Handbook of Crushing

PennsylvaniaCrusher

The Most Choices, The Most Experience

HANDBOOKOF

CRUSHING

®

With Posimetric® Feeders

2

We specialize in the manufacture of size reduction and feeding equipment and have pioneered manybasic designs. Pennsylvania® produces more types and sizes of crushers and breakers than any other firm inthe world and is known for offering, "The Most Choices, The Most Experience".

Established in 1905, our equipment is used by numerous basic industries such as power generation,mining, cement plants, food & chemical processing, the glass industry and many others. In the U.S. in fact, ahigh percentage of the coal needed to generate electric power is crushed using our equipment.

Our application expertise is second to none, and we invite you to take advantage of our help in solvingyour reduction or feeding problems.

THE TECHNOLOGY OF CRUSHING

The ability to crush material is governed by the laws of physics involving mass, velocity, kinetic energy,and gravity. However, it is impractical to reduce the process of selecting and sizing a crusher to a series offormulas. The selection process is largely based on experience and testing: experience with actual fieldapplications and laboratory tests that show how a given material will be reduced by a given crusher type.

The main purpose of this handbook is to explain the principles that govern the technology of crushingand also to impart the practical knowledge gained by Pennsylvania Crusher over the past century.

INTRODUCTION

600 Abbott Drive • Box 100 • Broomall, PA 19008-0100 U.S.A.Phone: (610) 544-7200 • Fax: (610) 543-0190

E-Mail: [email protected]

PennsylvaniaCrusher


®

Table of Contents

THE TECHNOLOGY OF CRUSHINGIntroduction .................................................................................................................................................................. 2Table of Contents ........................................................................................................................................................ 3Glossary of Terms ........................................................................................................................................................ 4Mechanical Reduction Methods .................................................................................................................................. 5Crusher Selection Criteria / Development of Job Specifications ................................................................................ 7Application Analysis Form............................................................................................................................................ 8Typical Screen Analysis .............................................................................................................................................. 9Crushing Tests ............................................................................................................................................................ 10How to Take Samples .................................................................................................................................................. 10Measuring Crushing Resistance .................................................................................................................................. 10Measuring Relative Abrasiveness................................................................................................................................ 10Index of Abrasiveness.................................................................................................................................................. 11Definitions of Material Characteristics.......................................................................................................................... 12Physical Characteristics of Materials .......................................................................................................................... 12Power Requirements.................................................................................................................................................... 13Closed Circuit Crushing .............................................................................................................................................. 13Hammer Technology .................................................................................................................................................... 14

FACILITIESFacilities and Organization .......................................................................................................................................... 15Parts and Service ........................................................................................................................................................ 21

PRODUCTS Complete brochures with specifications on individual products are available upon request.

BRADFORD BREAKERS• Roller Mounted Breakers .......................................................................................................................................... 23• Tri-Mounted Breakers ................................................................................................................................................ 23• Bradpactors................................................................................................................................................................ 24

CAGE MILLS .............................................................................................................................................................. 25

GRANULATORS.......................................................................................................................................................... 26

HAMMERMILLS• Reversible Hammermills for Coal .............................................................................................................................. 27• Reversible Hammermills for Fluid Bed Boiler Applications........................................................................................ 28• Reversible Hammermills for Rock, Limestone, Minerals and Chemicals .................................................................. 29• Non-Reversible Hammermills .................................................................................................................................... 29• Non-Clog Hammermills.............................................................................................................................................. 30

IMPACTORS• Coalpactors................................................................................................................................................................ 31• Aluminum Dross Impactors / Metallic Slag Crushers ................................................................................................ 32• Reversible Impactors ................................................................................................................................................ 33• Reversible Impactors, Small ...................................................................................................................................... 34• Twin Rotor Impactors ................................................................................................................................................ 34

JAW CRUSHERS ........................................................................................................................................................ 35

GRINDING MILLS• Brad-Multi-Roll Crushers .......................................................................................................................................... 36

ROLL CRUSHERS• Clinker Crushers ........................................................................................................................................................ 37• Single Roll Crushers .................................................................................................................................................. 38• Double Roll Crushers ................................................................................................................................................ 39• Frozen Coal Crackers................................................................................................................................................ 40

SIZERS ........................................................................................................................................................................ 41

POSIMETRIC FEEDERS ............................................................................................................................................ 42

PENNSYLVANIA BRADFORD HAMMERMILL® FROZEN COAL CRACKER® PENNSYLVANIA REVERSIBLE IMPACTOR® KOAL KING®

U.S. Patent Number 4,343,438

BRADPACTOR® FBR® COALPACTOR® BMR BRAD-MULTI-ROLL®

U.S. Patent Numbers 3,931,937; 4,009,834

POSIMETRIC® FEEDER PENNTECHNIC® PENNSYLVANIA®

Trademarks of Pennsylvania Crusher Corporation

©Pennsylvania Crusher Corporation 2000, 2002, 2003 3

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Angle of Nip The angle formed between the movingsurface of a crusher roll or jaw plate and thestationary plate surface, at which point thematerial will be pinched. Angle varies withmachine size and material lump size.

Bond Work Index (BWI) KW hr. per short ton required toreduce the material to 80% passing 100 microns.

Breaker Block (Breaker Plate) The steel anvil surface ofa crusher against which material is crushed byimpact or pressure.

Bridging Blocking of crusher opening by large pieces ofmaterial.

Burbank Abrasion Test A standard method of comparingthe relative abrasiveness of rocks, minerals andores.

Cage A screening device, fixed or adjustable, made ofprecisely spaced bars or slotted plate, where finalsizing is accomplished within the crusher.

Choke Feed Operating the crusher with a completely filledcrushing chamber.

Choke Point Place in the crushing chamber having theminimum cross section. All compression typecrushers have choke points, but this does notnecessarily mean that choking is likely to occur.

Choking Stoppage of the flow of material through thecrusher, usually the result of wet and stickymaterial clogging exit points.

Circulating Load The amount of oversize returned to thecrusher from a screen in a closed-circuit system.

Closed-Circuit Crushing A system in which oversizematerial is screened from the output and returnedfor another pass through the crusher.

D50 Denotes that output size is 50% smaller than thesize indicated.

Feed Input to the crusher.

Feeder A device that regulates and distributes materialinto the crusher.

Fines Material with particle size smaller than a specifiedopening.

Finished Product (Output) The resulting material after ithas been processed.

Friable Material that breaks easily.

Hammers Free-swinging or fixed metal impact surfacesattached to the rotor assembly of an impactor orhammermill crusher. Sometimes designated as“beaters”.

Hardgrove Index (HGI) The grindability of a coal isexpressed as an index showing the relativehardness of that coal compared with a standardcoal of 100 grindability.

Height of Drop Vertical, free fall distance from the lip ofthe feeding device to the inlet opening of animpactor or hammermill crusher. Normallyapplies to reversible machines.

Hopper The area of the crusher preceding the crushingchamber. Also, an external bin that holds the feedmaterial.

MOH Scale Relative hardness of material compared to 1-Talc, 2-Gypsum, 3-Calcite, 4-Fluorite, 5-Apatite,6-Feldspar, 7-Quartz, 8-Topaz, 9-Corundum, and10-Diamond.

Nominal Describes product size (output size), usuallydenoting that at least 90% of product is smallerthan size indicated.

Oversize Material too large to pass through a specific sizeof screen or grizzly opening.

Plugging Restriction of material flow through a crusher.

Primary Crusher The first crusher in a crushing systeminto which material is fed. Succeeding crushersin the system are referred to as secondary ortertiary crushers.

Product Output from the crusher.

Reduction Ratio The ratio of the top size of input materialto the top size of crusher discharge.

Reversible Crushers Hammermills and impactors withrotors that can be run both clockwise andcounterclockwise.

ROM Run Of Mine — Material from a mine that has notbeen crushed or screened.

ROQ Run Of Quarry — Material from a quarry that hasnot been crushed or screened.

Rotor Rotating assembly of shaft, discs, and hammerswithin a crusher which imparts the crushing forcesto the material.

Scalping Removing all sizes smaller than output top sizefrom the crusher input material.

Screen Bars The bars in the cage of a hammermill orgranulator, spaced to control the output size. Alsocalled “cage bars” or “grate bars”.

Slugger Teeth The large teeth on a single roll crusherwhich first strike the material.

Sorbent Stone, usually containing calcium; used to capturesulfur in a fluid bed boiler.

Tailings Refuse or residue material from a screeningprocess.

Top Size The largest particle size in an input or output size.

Tramp Iron Bolts, shovel teeth, picks, and other uncrush-able metal that is often present in crusher input.

GLOSSARY OF TERMS

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There are four basic ways to reduce a material — by impact, attrition, shear or compression —

and most crushers employ a combination of all these crushing methods

MECHANICALREDUCTIONMETHODS

THE TECHNOLOGYOF CRUSHING

ImpactIn crushing terminology, impact refers to the

sharp, instantaneous collision of one moving objectagainst another. Both objects may be moving, such asa baseball bat connecting with a fast ball, or one objectmay be motionless, such as a rock being struck byhammer blows.

There are two variations of impact: gravity im-pact and dynamic impact. Coal dropped onto a hardsurface such as a steel plate is an example of gravityimpact. Gravity impact is most often used when it isnecessary to separate two materials which haverelatively different friability. The more friable material isbroken, while the less friable material remainsunbroken. Separation can then be done by screening.

The Pennsylvania Bradford Breaker employsgravity impact only. This machine revolves so slowlythat for all practical purposes, gravity is the onlyaccelerating force on the coal.

Material dropping in front of a moving hammer(both objects in motion), illustrates dynamic impact.When crushed by gravity impact, the free-fallingmaterial is momentarily stopped by the stationaryobject. But when crushed by dynamic impact, thematerial is unsupported and the force of impactaccelerates movement of the reduced particles towardbreaker blocks and/or other hammers.

Dynamic impact has definite advantages for thereduction of many materials and it is specified under thefollowing conditions:

—when a cubical particle is needed—when finished product must be well graded

and must meet intermediate sizingspecifications, as well as top and bottomspecifications

—when ores must be broken along naturalcleavage lines in order to free and separateundesirable inclusions (such as mica infeldspars)

—when materials are too hard and abrasive forhammermills, but where jaw crushers cannotbe used because of particle shape require-ments, high moisture content or capacity

Dynamic impact is the crushing method used byPennsylvania Impactors.

AttritionAttrition is a term applied to the reduction of

materials by scrubbing it between two hard surfaces.Hammermills operate with close clearances betweenthe hammers and the screen bars and they reduce byattrition combined with shear and impact reduction.Though attrition consumes more power and exactsheavier wear on hammers and screen bars, it ispractical for crushing the less abrasive materials suchas pure limestone and coal.

Attrition crushing is most useful in the followingcircumstances:

—when material is friable or not too abrasive—when a closed-circuit system is not desirable

to control top size

ShearShear consists of a trimming or cleaving action

rather than the rubbing action associated with attrition.Shear is usually combined with other methods. Forexample, single-roll crushers employ shear togetherwith impact and compression. Shear crushing isnormally called for under these conditions:

—when material is somewhat friable and has a relatively low silica content

—for primary crushing with a reduction ratio of 6 to 1

—when a relatively coarse product is desired,usually larger than 11/2" (38mm) top size

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CompressionAs the name implies, crushing by compression

is done between two surfaces, with the work being doneby one or both surfaces. Jaw crushers using thismethod of compression are suitable for reducingextremely hard and abrasive rock. However, some jawcrushers employ attrition as well as compression andare not as suitable for abrasive rock since the rubbing

action accentuates the wear on crushing surfaces. As amechanical reduction method, compression should beused as follows:

—if the material is hard and tough—if the material is abrasive—if the material is not sticky—where the finished product is to be relatively

coarse, i.e., 11/2" (38mm) or larger top size—when the material will break cubically

The Pennsylvania Jaw crushes by compressionwithout rubbing. Hinged overhead and on thecenterline of the crushing zone, the swinging jawmeets the material firmly and squarely. There is norubbing action to reduce capacity, to generate fines orto cause excessive wear of jaw plates.

Single Roll Crushers reduce large input by a combinationof shear, impact and compression. They are noted forlow headroom requirements and large capacity.

When a Pennsylvania Non-Reversible Hammermill is usedfor reduction, material is broken first by impact betweenhammers and material and then by a scrubbing action(shear and attrition) of material against screen bars.

The bottom of the Pennsylvania Reversible Impactor isopen and the sized material passes through almostinstantaneously. Liberal clearance between hammers andthe breaker blocks eliminates attrition, and crushing is byimpact only.

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CRUSHERSELECTIONCRITERIAWhen selecting a crusher, the following criteria must be considered:

1. Will it produce desired output size and shape at the required capacity?

2. Will it accept the largest input size expected?

3. What is its capacity?

4. Will it choke or plug?

5. Can it pass uncrushable debris without damage to the crusher?

6. How much supervision of the unit is necessary?

7. Will it meet product specifications without additional crushing stages and auxiliary equipment?

8. What is the crusher’s power demand per ton per hour of finished product?

9. How does it resist abrasive wear?

10. Does it operate economically with minimum maintenance?

11. Does it offer dependable and prolonged service life?

12. Is there ready availability of replacement parts?

13. Does it have acceptable parts replacement cost?

14. Does it have easy access to internal parts?

15. Is the crusher versatile?

16. How does the initial cost of the machine compare with its long term operating costs?

17. Is experienced factory service readily available?

The initial steps in selecting the proper crusherrequire the development of complete job specifica-tions, including the pertinent physical characteristics ofthe feed material.

The Application Analysis Form that appearshere is designed to simplify the task of collecting jobspecifications. In most cases, the completed form willenable the engineering staff of Pennsylvania Crusherto recommend the crusher best suited to meet therequirements.

On occasion, it may also be necessary tosupply actual samples of the material for test crushingin the Pennsylvania Crusher test facilities. Refer toPage 8 for “How to Take Samples”.

Additional copies of the Application AnalysisForm (Page 6) may be obtained by photocopying or byrequest. If you have any questions regarding thecompletion of this form, please contact PennsylvaniaCrusher Corporation.

DEVELOPMENT OF JOB SPECIFICATIONS

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a. Material: ________________________________________________________________________________b. Bulk Density: _____________________________________________________________________________c. Moisture:_______________________________%Total_______________%Surface_____________________d. Compressive Strength (PSI) _________________________________________________________________e. MOH Hardness/Hardgrove Index:_____________________________________________________________f. Material Temperature:___________________Degrees F:____________________Degrees C:_____________g. Material is:

Free-Flowing ( ) Sticky ( )Non-Abrasive ( ) Mildly Abrasive ( ) Very Abrasive ( )

h. Other Characteristics: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

a. Mining Method or Process Source:____________________________________________________________b. Feed Size (Maximum): _______________________ X________________________X___________________c. Desired Product Size (State size and % passing):________________________________________________d. Is product size material removed from feed prior to crushing? ______________________________________

What percentage is removed? _______________________________________________________________e. Are fines: ( ) desirable ( ) undesirable ( ) no preference

If undesirable, at what size? _________________________________________________________________f. Can external screens be used to return oversize to crusher (closed-circuit)? ___________________________g. Capacity desired (tons per hour): _____________________________________________________________

a. Crusher will: ( ) replace existing equipment ( ) be used in new operationb. Project is: ( ) study for feasibility or budget purposes

( ) funded for purchase. Expected purchase date:________________________________c. Delivery is required by: _____________________________________________________________________

_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

APPLICATION ANALYSIS FORMCompletion of this sheet will help ourengineers select the crusher best suited toyour requirements.

Box 100Broomall, Pennsylvania 19008-0100, U.S.A.Telephone: 610-544-7200Fax: 610-543-0190E-Mail: [email protected]

COMPANY: __________________________________________

ADDRESS: __________________________________________

CITY: ________________________________________________

STATE:______ ZIP:_____________ COUNTRY:______________

NAME AND TITLE: ____________________________________

PHONE: ______________________________________________

FAX: ________________________________________________

E-MAIL:______________________________________________

1.MATERIAL

DESCRIPTION

2.APPLICATION

REQUIREMENTS

3.GENERAL

INFORMATION

4.OTHER

INFORMATIONWHICH MAY BE

OF VALUE

PennsylvaniaCrusher

DATE:____________________________________________

PROJECT: ________________________________________

PROJECT LOCATION: ______________________________

______________________________________________________

______________________________________________________

PROJECT REFERENCE NUMBER:____________________

______________________________________________________

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CRUSHINGTESTS

When a new or unusual application is encoun-tered, samples of the material may be crushed todetermine which crusher is most suitable. This is donein the Pennsylvania Crusher Test Laboratory. By crush-ing samples of the material, significant facts can belearned for predicting the performance of full capacitymachines with acceptable accuracy.

Laboratory tests can prove or disprove the rel-ative merits of various types of crushers. They alsoprovide an opportunity to evaluate the effects of variouscrusher settings, speeds, feeding methods, height-of-drop, and size or shape of hammers and breaker blocks.In the lab, one element at a time can be changed whileall others are held constant. Under such conditions, anychanges in crushing results can be isolated andevaluated by our application engineers.

Testing ProcedureThe normal procedure is to test crush a repre-

sentative sample of the material and to then determinethe product size gradation. From this data, a graph isplotted showing the cumulative percentage of materialpassing each screen size. Page 7 illustrates a typicalscreen analysis derived in this manner.

By comparing screen analyses and othercriteria with those associated with familiar materials, anexperienced crusher application engineer can estimateoverall crushing performance as well as power require-ments. The engineer can also detect characteristicsthat require special design considerations or auxiliaryequipment.

Deciding FactorsTests may show that two or more types of

crushers will perform equally well on a particularmaterial. But other factors must still be considered suchas headroom, desirability of fines, product shape,economics of maintenance and operations, and theadaptability of the crusher to future plant expansions.

HOW TO TAKE SAMPLES

To ensure meaningful results from thePennsylvania Crusher Test Laboratory, it is importantthat a truly representative sample of material be pro-vided. Care must be taken to ensure that the sample iscollected from a true cross section of the material andthat it is packed to retain its original characteristics(moisture, size, shape, etc.).

A 55-gallon steel barrel of material will usuallybe an adequate amount for testing.

Measuring Crushing ResistanceA basic premise in equipment selection is that

the crusher be stronger than the material that it mustcrush. How strong are rocks and ore? While there is nodirect measurement of “resistance to crushing”, it ispossible to measure compressive strength and theelastic properties of a material.

The graph shows a typical plot of test results fordifferent materials, and it demonstrates the relationshipbetween compressive load and resulting displacement.The material exhibiting twice as much displacementunder compression will normally require twice as muchpower to be crushed.

A.S.T.M. Method C-170-50 is used to obtain thehighest accuracy in measuring compressive strength.However, the Pennsylvania Crusher laboratory hasdeveloped a procedure that is more practical for crusherselection. This procedure is fully described in an articleby Benjamin B. Burbank, entitled “Measuring theCrushing Resistance of Rocks and Ores”. Copies areavailable from Pennsylvania Crusher Corporation.

Measuring Relative AbrasivenessIt is difficult to predict the abrasive action of

rocks, minerals, and ores. Often, rocks belonging to thesame geological classification will vary widely inabrasiveness from one locality to another. Therefore, inorder to select the proper crusher, we must have somereliable measurement of the abrasiveness of the specificmaterial.

Abrasiveness can be determined either fromprior experience or by testing in semi-production plants,but a simpler method has been developed byPennsylvania Crusher Corporation. This involves

.004" .008" .012" .016" .020" .024"0

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Cement rock, NY

Colorado oil shale, CO

Feldspar, NH

Cement rock, Thomaston, ME

Dolomite, NY

Sandstone, AZ

Iron ore, Ozark Mts., AR

Graphic granite (feldspar), NY

Chert, Picher, OK

Granite, Winterport, ME

Quartzite, VT

DISPLACEMENT (Inches)

COMPRESSIVE LOAD(x 1,000 psi)

11

testing, and it is a reliable way to establish relativeabrasiveness by using four 400-gram samples of thematerial to be crushed.

Each sample of material is rotated for 15 min-utes in a drum with a steel paddle. After the four sepa-rate batches are run, the average milligrams of weightloss by the paddle is measured. This will serve as arelative index of abrasive action. The higher the index,the greater the abrasiveness.

This test provides the most practical index ofabrasiveness available today. Such test data has beencollected for many years on numerous samples of rocksand ores. Typical scales of relative abrasiveness derivedfrom this testing procedure are shown in the table below.A more complete description of the method andequipment for obtaining these abrasiveness indices iscontained in our publication entitled, “Measuring theCrushing Resistance of Rocks and Ores.”

INDEX OF ABRASIVENESSMATERIAL AND SOURCE ABRASIVENESS INDEX

Highly AbrasiveManganese Ore, Georgia ............................................................................................................................................................................ 32,946Aluminum Oxide, New York......................................................................................................................................................................... 14,114Sandstone, Pennsylvania ............................................................................................................................................................................ 13,121Oxygen Furnace Slag, Ontario.................................................................................................................................................................... 10,828Chert, Missouri ............................................................................................................................................................................................ 9,829Stone and Bauxite Clinker, Indiana ............................................................................................................................................................. 9,489Gravel, Mississippi....................................................................................................................................................................................... 8,888Stone, Virginia ............................................................................................................................................................................................. 7,969White Quartz, Maine.................................................................................................................................................................................... 7,000Calcined Alumina, Louisiana ....................................................................................................................................................................... 6,879Open Hearth Pot Slag, New York................................................................................................................................................................ 6,830High-Silica Limestone, Pennsylvania .......................................................................................................................................................... 4,838Granite, Puerto Rico .................................................................................................................................................................................... 4,517Feldspar, Virginia ......................................................................................................................................................................................... 3,650Burned Brick and Tile, Pennsylvania........................................................................................................................................................... 3,491Sintered Ore, Alabama ................................................................................................................................................................................ 3,065Trap Rock, Pennsylvania............................................................................................................................................................................. 2,928Feldspar, New Hampshire ........................................................................................................................................................................... 2,871Tungsten Ore, California ............................................................................................................................................................................. 2,253Cement Clinker, Pennsylvania..................................................................................................................................................................... 2,206

Abrasive (Wear can be minimized by design and materials of construction)Iron Ore, Missouri ........................................................................................................................................................................................ 1,992Transvaal Chrome Ore, South Africa .......................................................................................................................................................... 1,755Coke Breeze, Alabama................................................................................................................................................................................ 1,690Calcined Bauxite, Missouri .......................................................................................................................................................................... 1,671Red Limestone, Vermont ............................................................................................................................................................................. 1,452Scoria Volcanic Cinder ................................................................................................................................................................................ 1,352Cement Clinker, Quebec ............................................................................................................................................................................. 1,231Grog, New Jersey........................................................................................................................................................................................ 1,052Amorphous Silica, Illinois............................................................................................................................................................................. 978Travertine, Australia..................................................................................................................................................................................... 838Phosphate Nodules, Tennessee.................................................................................................................................................................. 813Cement Clinker, Kentucky ........................................................................................................................................................................... 695Hematite, Venezuela ................................................................................................................................................................................... 620Barite, Arkansas .......................................................................................................................................................................................... 550Limestone, Indiana ...................................................................................................................................................................................... 526Dolomitic Clinker, Ohio ................................................................................................................................................................................ 494Cement Rock, Brazil.................................................................................................................................................................................... 444Ferro-Phosphorous, Oklahoma ................................................................................................................................................................... 443Dolomite, West Virginia ............................................................................................................................................................................... 417

Low in Abrasion (Parts wear is not critical)Shale, Virginia ............................................................................................................................................................................................. 345Antimony Ore, New Jersey.......................................................................................................................................................................... 315Oil Shale, Colorado ..................................................................................................................................................................................... 270Chamotte, Michigan..................................................................................................................................................................................... 250Zinc Sinter, Pennsylvania ............................................................................................................................................................................ 249Limestone, Ohio .......................................................................................................................................................................................... 241Extruded Zircon, New Jersey ...................................................................................................................................................................... 186Weathered Shale, Virginia........................................................................................................................................................................... 131Zinc Oxide, Pennsylvania ............................................................................................................................................................................ 78Diatomaceous Shale Clinker, England ........................................................................................................................................................ 78Dolomite, Alabama ...................................................................................................................................................................................... 62Sandstone, California .................................................................................................................................................................................. 38Red Flux, Australia ...................................................................................................................................................................................... 31Shale, Virginia ............................................................................................................................................................................................. 30Clay, Pennsylvania ...................................................................................................................................................................................... 25Cement rock, Pennsylvania......................................................................................................................................................................... 13Anhydrite, Kansas ....................................................................................................................................................................................... 9Limestone, Australia .................................................................................................................................................................................... 7

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DEFINITIONS OF MATERIAL CHARACTERISTICS

Selection of the most appropriate crusher is greatly influenced by the precise nature of the material to be crushed. The listingsthat follow serve to illustrate how even the same basic materialscan vary widely. Such variances will definitely influence the type of crusher that should be employed.

CLASSLow abrasiveness..................................................................................................................................... 1Mildly abrasive.......................................................................................................................................... 2Very abrasive............................................................................................................................................ 3

Very free flowing - angle of repose up to 30°........................................................................................... 4Free flowing - angle of repose 30°-45° .................................................................................................... 5Sluggish - angle of repose 45° and up..................................................................................................... 6

Hygroscopic.............................................................................................................................................. AHighly corrosive ........................................................................................................................................ BMildly corrosive......................................................................................................................................... CDegradable when exposed to air ............................................................................................................. DVery friable................................................................................................................................................ EMildly friable.............................................................................................................................................. FTough - resists reduction .......................................................................................................................... GPlastic or sticky......................................................................................................................................... H

SPECIALCHARACTERISTICS

PHYSICAL CHARACTERISTICS OF MATERIALS

*Refer to table above for class description

MaterialAluminaAluminum OxideBagasseBariteBark (wood refuse)Basalt (broken)Bauxite (crushed)BentoniteBrickCarbon Electrodes (baked)Carbon Electrodes (unbaked)Cement ClinkerCement RockCharcoalClay (dry)Calcined ClayCoal - AnthraciteCoal - BituminousCoal - Sub-bituminousCoke - PetroleumCryoliteCullet - GlassDiatomaceous EarthDross - AluminumFluorsparFullers Earth - rawGranite - brokenGravelGypsum Rock

Class*3-5-G3-G1-6-C3-52-6-G3-G3-5-F2-53-F2-G1-F3-5-F2-5-F2-5-D-F3-53-F1-4-D-E1-5-C-D-E1-5-C-D-E2-51-5-F3-5-E23-F-C2-5-F2-53-5-G-H3-5-F2-5-F

Average Weight in Lbs.Per Cubic Foot

6070-1207-8140-18010-2010-2075-8540-50100-125——75-95100-11018-2560-7580-10055-6045-5545-5535-4211080-12011-14—90-10035-4090-10090-10090-100

MaterialLignite - Texas (ROM)Lignite - Dakota (ROM)Lime - PebbleLimestone - brokenManganese OreMarble - brokenMarl - raw & wetMiddlings - CoalPhosphate – Rock - OrePotash OrePotash Ore Compactor FlakeQuartz - brokenRefuse - householdSand - dry bankSand - foundrySandstone - brokenShale - brokenShells - OysterDiacalcium PhosphateDolomiteSlag - Open HearthSlag - Blast FurnaceSlateSoapstone (talc)SuperphosphateTraprock - brokenTriple SuperphosphateTrona OreTungsten Carbide

Class*1-5-D-E1-6-D-F1-5-E2-5-F3-5-G2-5-F2-6-E-H2-5-G-F2-51-E1-E3-5-E2-G3-53-53-F2-5-F2-5-E2-5-E-H2-5-F3-G3-4-F-E2-E1-F2-6-F-H3-52-6-F-H2-5-F3-4-G

Average Weight in Lbs.Per Cubic Foot

45-5045-5053-5690-100125-14090-100130-140————85-9545-5090-11090-11085-9090-10070-804390-100160-18080-9085-9540-5050-55105-11050-5590-100—

ABRASIVENESS

FLOWABILITY

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In crushing, the useful or meaningful work isthat expended to reduce the material to a given size. Anumber of theories have been expressed to define therelationship between work input and size reduction.Kick’s Law states that work done is proportional to thereduction in volume of particles, a theory which appliesto the crushing of large particles. However, finerproduct sizes conform more closely to Rittinger’sTheory which concludes that work required isproportional to the new surface area formed, andinversely proportional to the product diameter.

In any case, reduction ratio is not the only factorin determining power requirements. Nearly all crushingprojects differ from one another in one or more aspects,and no hard and fast rule can be applied with regard topower consumption. However, through extensiveexperience in the field of mechanical reduction, someaverage values have been compiled regarding thepower requirements of different types of crushers.

Typical Horsepower RequirementsIt has been determined that a primary single roll

crusher, reducing run of quarry medium-hard limestoneto a 6" (150mm) product will require approximately 1/2

horsepower per ton per hour (HP per TPH). However,when crushing medium-hard bituminous coal to thesame specifications, the power demand is only 1/12 HPper TPH. Even on the hardest materials, single rolls donot require more than one full HP per TPH and maydemand as little as 1/25 HP per TPH.

Coalpactors for preparing coking coal for cokeovens are fed with 3" (75mm) and under bituminouscoal. The product usually desired is 80-85% minus 1/8"(3mm). For this service, 11/2 to 2 HP per TPH is nor-mally required.

In cement plants, where hammermills orimpactors are used for secondary crushing of cementrock, the feed is approximately 6-10" (150 - 250mm) andthe product is a nominal 1/2 " (12mm). This reductionneeds 11/3 to 11/2 HP per net TPH.

Impactors generally require approximately 1 HPper TPH (gross load) to drive them. This may be slightlyincreased if an extremely fast rotor speed is required.

Granulators (ring hammermills) are most oftenused in the coal handling facilities of power stationswhere they reduce run of mine coal to a nominal 3/4"(19mm) product. This typically requires 1/2 HP per TPH.

The Pennsylvania Jaw Crusher requiresapproximately 1/3 or less HP per TPH, depending uponthe reduction ratio desired.

Bradford Breakers and Bradford Hammermillsrequire approximately 1/4 or less HP per TPH.

Motor SelectionThe foregoing figures are averages, and each

crushing problem should be carefully studied beforeselecting motors. We urge all prospective customers toconsult us prior to selecting motors, since so manyfactors will affect power demand. Our experience withsuch diverse types of crushers will serve as a guide forproper motor selection.

CLOSED-CIRCUIT CRUSHINGClosed-circuit crushing is a means of controlling

product top size by screening the product and thenreturning oversize material to the feed end of thecrusher for another pass through the machine. While itmay be possible to obtain a specified top size fromcrushers without using a closed-circuit system, it is notalways desirable. To control top size from a singlecrusher operating in an open circuit, material mustremain in the crushing chamber until it is reduced. Thisresults in overgrinding a percentage of the product, witha corresponding increase in fines and a loss ofefficiency.

In a typical multiple-stage crushing plant withthe last stage operated in closed-circuit, the primarycrusher operates at a setting which produces asatisfactory feed size for the secondary crusher, so thata balance exists for the work done by each crusher.

POWERREQUIREMENTS

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Hammer design plays a significant role incrusher efficiency, because in most types of crushers,the hammers do most of the work. Early hammerdesigns were only concerned with mass and generalshape of the hammer. Today the technology ofPennsylvania hammers is highly developed, and wegive careful consideration to a great many factors:

Location of the hammer’s center of gravity

The center of gravity determines the focus ofimpact, which in turn helps to control the amount ofimpact and the general shape of the shattered particle.The center of gravity must be controlled to utilize the fullmass of the hammer against the feed.

Air paths created by hammer rotation

The air paths created by the hammer sweepusually contain a certain amount of fines and other smallparticles which must be directed away from the hammershanks and rotor discs; otherwise premature wear wouldoccur. Pennsylvania hammers are designed so that theresulting air paths are directed toward open areas of thecrushing chamber, away from vital parts.

Edge configuration of the hammer head

The edges of each Pennsylvania hammer faceare shaped to a special geometry in order to producemaximum hammer life with the lowest amount of friction.

Heat treating

Hammer hardness is the most essential factorin determining hammer life, for while the hammer headmust be extremely hard and resistant to wear, the shankmust be more ductile in order to absorb shock. Toproduce this on certain designs, Pennsylvania uses aspecial method of heat treating that creates a graduallyvarying hardness between the shank and the tip,without any abrupt changes. However, in cross section,the hardness extends for the full depth instead of merelythe surface. Hammer hardness is normally gaugedaccording to the Brinnel method.

As a result of continued improvements,Pennsylvania hammer design plays a major role inproducing high efficiency and in reducing maintenanceproblems. As the company introduces refinements tothe hammers, users are provided with the latest designsas part of their normal resupply orders.

CRUSHERHAMMERTECHNOLOGY

BAR HAMMER

T-HEAD HAMMER

RING-TYPE HAMMER (plain)

RING-TYPE HAMMER (toothed)

B A S I C H A M M E R T Y P E S

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FACILITIES ANDORGANIZATION

Pennsylvania Crusher possesses the most modern facilities in the world devotedto the design and manufacture of crushers. Still, our company’s most valuable assetsreside in the talents of the skilled professionals who staff our many departments.

Design engineering, application engineering, field service, parts, production,finance, marketing, research and development — all work together to provide equipmentthat will perform best in your application, with full factory support throughout theoperational life of your crusher.

For an evaluation of your needs, please contact us at any time. We believe youwill be impressed with the experience, the proficiency and the helpful attitude you find atevery level within Pennsylvania Crusher.

Pennsylvania CrusherManufacturing Plant (top)in Cuyahoga Falls, Ohio,

and Headquarters in Broomall, Pennsylvania.

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Our manufacturing facility is located inCuyahoga Falls, Ohio, near Akron, and is adjacentto major rail and highway arteries. This facilitycontains every type of manufacturing equipmentneeded to produce the numerous types and sizes ofcrushers and feeders sold by Pennsylvania Crusher.

An exceptionally high percentage of our manufacturing specialists arequalified journeymen, with a minimum of 8,000 hours of on-the-jobtraining, coupled with years of formal schooling.

In terms of hands-on experience, fully half of us haveserved under the same roof for over ten years, and manyhave over twenty and thirty years to our credit.

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We also handle the repair and remanufacture of Pennsylvania crushers, includingrotor and cage assemblies and other components. This enables the customer toupgrade to a new design, in order to achieve current operating efficiencies, alongwith a new parts warranty.

We operate a Crushing Test Laboratory, fully equipped withvarious models of crushers. Test crushing your material inadvance of purchase enables us to determine which model andsize of crusher will be the most suitable. It also enables us todetermine wear rates, height-of-drop data and other valuableinformation.

Analyses of materials, equipment and parts by ourtesting laboratory constitute the basic data fromwhich recommendations will be made for selectionand sizing of crushers.

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Design Engineering. This group is the source of numerous innovations in crusher design . . . includingsome basic crushing methods that have been adopted by the entire industry.

Our extensive use of computer-aided design (CAD) helpsto speed the completion of new equipment designs.

All operations of Pennsylvania Crusherare linked by an integrated, state-of-the-artmanagement program that embraces advanceplanning, accounting, engineering, order entry,scheduling, manufacturing, shop floor reporting,and shipping.

This has enhanced our ability to provideyou with timely information regarding the statusof your order, and to expedite manufacture tosuit your schedule.

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Communications Center. This group isresponsible for our company’s contact with allpoints on the globe. The innovative equipmentused here helps to enhance the speed andaccuracy of communications.

Field Service. We can supply trained personnel tosupervise the installation of Pennsylvania Crushers.Their practical and extensive experience helps toachieve significant cost savings.

Management Information Systems. Computer-based procedures haveenhanced Pennsylvania’s customer service and order acknowledgmentsystems. They also help the company to achieve more accurate levelsof inventory to meet changing customer needs.

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Sales and Applications Engineering. These groups possess unparalleled skill and experience with material reduction projectsworldwide. To complement the high professional expertise of each member, the application department maintains one of the mostextensive data bases of information about materials, equipment, and test results on tens of thousands of mineral samples from everycontinent.

Accounting and FinanceGroup. The significant

financial strength of ourcompany is enhanced by

the efficiency and smooth operation of thisdepartment. This section

is staffed by professionalswho clearly understand

the special requirementsof the markets we serve.

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Parts & Service Group. This group goes farbeyond the usual concept of simply supplyingreplacement parts. They operate under a philosophy ofservice completely oriented to the continuing needs of the customer, regardless of whether thecustomer is working with new Pennsylvania equipmentor with equipment that was placed in service over ninetyyears ago.

As part of this practice, there are threeimportant areas in which this department is of practicalservice to customers:

1. Basic supply requirements.

2. Refinements to older design equipment forimproved performance.

3. Major modifications to equipment either forimproved performance or for different applicationsthan that for which it was originally designed.

For maximum effectiveness, the Pennsylvaniaparts staff maintains thoroughly detailed records on all machines shipped, including details of past

modifications, service records and all other pertinentdata. Complete drawings are kept on modifications asfar back as ninety years, for there are numerousinstances where such Pennsylvania equipment is still inproductive service.

The Parts Department operates almost as anextension of the customer’s maintenance department,since the objectives are similar, i.e., to keep theequipment operating effectively and economically.Parts and Service sales representatives are availablefor consultation with the customer on questionsregarding parts, service, or modification work.

Electronic Data InterchangeOur on-line system for electronic data

interchange (EDI) speeds the flow of acknowledgments,RFQs, POs and invoices, using a standard, ready-to-process form.

If you already have such a system, pleasecontact us about establishing a link directly to yourcompany or to your consulting service.

The Pennsylvania Crusher Parts and Service Group has forged a reputation for responsiveness, experience and versatility.

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These machines are used for crushing, sizing,and cleaning of run-of-mine coal and other friablematerials. They are used to produce a product that isrelatively coarse, with minimum fines, and that is 100%to size.

Bradford Breakers crush by gravity impact only.A large cylinder made of perforated screen plates isfitted with internal shelves. As the cylinder rotates, theshelves lift the feed and, in turn, the feed slides off theshelves and drops onto the screen plates below, whereit shatters along natural cleavage lines.

The size of the screen plate perforationsdetermines the product size. Sized product fallsthrough these perforations but oversized pieces willagain be lifted and dropped by the shelves until they toopass through the screen plates.

Tramp iron, lumber, or other uncrushable debristhat enters the breaker along with the feed istransported to the discharge end of the cylinder. There,these uncrushables are scooped out continuously by arefuse plow which channels this debris out of thecylinder and into a disposal bin.

Often a Pennsylvania Bradford Breaker is usedmerely to clean debris from coal that has already beensized. This gives some indication of the economy ofoperation and versatility of this machine.

Breaker cylinders rotate at slow speeds of 12 to14 RPM depending upon cylinder diameter. Comparedwith most other crushers, Bradford Breakers areextremely long lived. Screen plates, for example,frequently last ten years or more, crushing millions oftons of coal, and there are numerous examples ofPennsylvania Bradford Breakers in continuous servicefor upwards of forty years.

Pennsylvania has also designed the screenplates in the breakers to be interchangeable, so that thescreen plates from the feed end, where wear isgreatest, can be switched with screen plates from otherareas of the cylinder where there is less wear.

The profile of the perforations in the screenplates has been scientifically designed to obtain amaximum self-cleaning effect, without product bridgingacross the perforation itself.

BRADFORD BREAKERS

PENNSYLVANIACRUSHERPRODUCTS

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Roller Mounted

Many prefer this model because its threesupport points provide a stable yet forgiving platform,minimizing the attention to wheel alignment needed withthe roller mounted arrangement to compensate forshifting foundations.

This model also features the design standardsfound on our other Bradford Breakers such as lapped

screen plates, adjustable feed plows, and roller chaindrive.

Longitudinal beams are bolted to the end cones— never welded — so that replacement can easily beaccomplished at your job site. These, plus numerousother features, make this an extremely low maintenancebreaker.

TRI-MOUNTED BRADFORDBREAKERS(Not illustrated)

ROLLER MOUNTEDBRADFORD BREAKERS

The roller mounted Bradford Breaker is suitedfor coal mines where the feed often includes unusuallylarge pieces of coal. This model will readily acceptthese larger pieces of coal without blocking the entry.

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The Bradpactor is a highlysuccessful innovation based on theBradford Breaker design. In the Brad-pactor, the breaker cylinder isequipped with a rotor that is mountedwith a series of paddle hammers. Therotor runs the entire length of thecylinder and the speed of the rotor canbe varied.

This gives operators the abilityto “tune” the Bradpactor to the type offriable material that is to be crushed.The paddles impact against theoversize material dropped into theirpath by the rotating cylinder. Thepaddles drive the material against thecylinder walls until the product is sizedand screened out through the screenplate holes.

By varying the rotor speed,impact force as well as fines can becontrolled. Compared with a breaker,a Bradpactor gives greater capacitywhile occupying far less space than aconventional breaker.

PENNSYLVANIA BRADPACTORS

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This crusher is employed for size reduction offriable, dry bulk substances such as chemicals, grain,fertilizer, coal, slag, glass, soap and many others. It’salso used for beneficiation of materials that vary inhardness.

In this model, material is reduced in size purelyby impact. Feed enters the innermost cage where it isinitially struck by the first row of sleeves. They scatterthe shattered material toward the next row which rotatesin the opposite direction.

Further reduction occurs in that and eachsuccessive row until the material exits the final row, tobe thrown against impact plates that line the crushingchamber. The sized material then discharges throughthe open bottom of the mill.

For production of fine, medium or coarse sizes,the spacing between sleeves on each row can beselected. Product size can also be changed by varyingthe speed of the cages.

We have improved the cage mill design inseveral ways. For example, the two motors used todrive the cages are on the same side, away from thefeed area, so as not to interfere with access to thecrushing chamber for maintenance. This arrangementalso produces a smaller footprint than ordinary cagemills, thereby allowing use of a smaller, less costlyfoundation. Additionally, total access to the wholeinterior is provided by the hinged hopper door. It swingswide open, completely out of the way, and an integralcage hoist can be installed at our factory or added later.

We normally recommend that your material betest crushed in the full-scale cage mill at our CrushingTest Facility in Broomall.

CAGE MILLS

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GRANULATORS

Pennsylvania Granulators use rows of ringhammers which crush with a slow, positive rolling action.This produces a granular product with minimum fines.

Offered in three models and nearly fifty sizes,Granulators are used for crushing coals, particularly forpower plants. They are also used for gypsum, salt,chemicals and moderately hard materials.

Granulators crush by a combination of impactand rolling compression, producing high reduction ratiosat high capacities. Product size is determined by screenopenings, and is adjusted by changing the clearancebetween the cage and the path of the ring hammers.

All Pennsylvania Granulators possess anexternal adjustment for the cage assembly which isoperable while the crusher is operating. Granulatorsalso have a tramp iron pocket for continuous removal ofuncrushables from the crushing zone.

This series includes the Koal King® Granulator, amachine that crushes fuel for both pulverized coal boilersand fluid bed boilers.

The Koal King Granulator will handle virtuallyany type of coal, including low quality coals that are wet,frozen, high in fines, or high in ash content, with virtuallyno clogging problems.

It has a number of important servicing advan-tages. It opens like a clamshell to expose the inside ofthe machine for inspection or maintenance, withoutdisturbing the feed system.

The rotor can be removed through the openingquickly and easily, and rigging to open the rear quadrantis totally unnecessary when the optional hydraulic dooropener is specified.

The Koal King Granulator accepts feed sizes upto 12" (300mm). Product sizes of 100% minus 1/2" (12mm) can be maintained when necessary.

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HAMMERMILLS

Hammermills are among the oldest, yet still themost widely used crusher designs. Although recentyears have witnessed the introduction of new types ofcrushers, many are a refinement of the basic hammermilldesign to serve more specialized purposes.

Pennsylvania Hammermills crush material intwo stages: First, the material is reduced by dynamicimpact; crushing then occurs by attrition and shear inthe second zone, where small clearances exist betweenhammers and screen bars. This second zone is thefinal sizing zone for the product.

One of the advantages of PennsylvaniaHammermills is their ability to produce the specified topsize without the need for a closed-circuit crushing

system. Hammermill crushing produces a cubicalproduct with a minimum of flats and slivers, and isrecommended when the material to be crushed is notunusually abrasive. In a Hammermill, large particlescannot escape the cage bars until sized, resulting ingreat product uniformity with a minimum of oversize.

Hammermills have high reduction ratios and willproduce high capacities whether used for primary,secondary or tertiary crushing. Cages can be adjustedto regulate product size, and a tramp iron pocket isstandard on all models.

REVERSIBLE HAMMERMILLSPennsylvania Reversible Hammermills are

symmetrically designed crushers with a rotor that canbe run clockwise or counter-clockwise. Reversal of therotor permits the operator to utilize the opposite face ofthe hammer daily for maximum hammer sharpness.This ability to reverse totally eliminates the requirementof manual hammer reversal.

In addition to more effective use of thehammers, reversal also brings the opposing set ofbreaker blocks and screen bars into use. The user of aReversible Hammermill virtually has two crushers in onemachine, reversal being done with a simple motorswitch.

REVERSIBLEHAMMERMILLS FOR COAL

Pennsylvania builds this Reversible Hammer-mill specifically for the reduction of pulverizer coals,cyclone fuel and other finely crushed coal.

To produce the smaller product sizes required,this model has more rows of hammers than are found inthe Reversible Hammermills used for stone or rock.

The internal configurations of the coal and rockmodels differ, though the crushing actions are similar.

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These units are specifically designed to reduceboth fuels and sorbents in fluid bed boiler applications.They meet the needs of utility and cogeneration plantsfor crushers that perform effectively and efficiently.

They are also suitable for similar reductionproblems in other industries.

Low investment cost and low power con-sumption have enabled these units to enjoy rapidacceptance. While they constitute the state-of-the-art ofthis technology, their design is based upon ourcompany’s many decades of experience with reversiblehammermills of many types.

Pennsylvania’s exclusive high performance,forged steel hammers are supplied for most applica-tions. Alloy steel is used for breaker plates, scrubberand screen sections.

Both sides of these units open fully for completeaccess to the crushing chamber. Product sizing andwear compensation are accomplished by adjusting thecage, and a tramp iron pocket is included for protectionof the rotor. Options include air sweeping and drying.

As plant needs change in future years, thisdesign readily allows for modifications that can beperformed whenever needed without compromising theoriginal investment in this equipment.

Our extensive experience with fluid bedapplications will allow us to determine the configurationand size that match the needs of your plant. We alsoprovide peripheral equipment and systems as neededto ensure a fully integrated operation.

REVERSIBLE HAMMERMILLS FOR FLUID BED BOILER APPLICATIONS

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REVERSIBLE HAMMERMILLSFOR ROCK, LIMESTONE,MINERALS AND CHEMICALS

In these machines, the breaker blocks and the cagebars are more massive than those used for crushing coal orother relatively friable materials.

This type of Reversible Hammermill has fewer rowsof hammers than the coal version, and the hammersthemselves are of a different type and size.

These are used for primary or secondary reduction ofdry, friable, low abrasive rocks, ores and chemicals,particularly when uniform product gradation is important.

This type of crusher is often used for primarycrushing of quarry-run feed to the final product size in a singlepass. It is also used for secondary crushing when oversizemust be controlled, but where a closed-circuit crushingsystem is not practical.

Size reduction starts by impact when the hammerstrikes the material as it enters the crushing zone. Shatteredfragments are swept down into the final crushing zone forfurther reduction at the pinch points between the hammersand screen bars. Oversize material remains in the machineuntil it is reduced sufficiently to fit through the screen baropenings.

Some of these models are available with adjustablecages, a feature that permits the user to make changes in theproduct size and compensate for wear. The tighter theclearance between the screen bars and hammers, thesmaller the particle size of the crushed product. However,major product size changes are controlled by changing theindividual screen bar openings.

When the machine has no adjustable cage, hammerwear is compensated for by resetting the hammer suspensionbars closer to the outside edges of the rotor discs, and bymoving the breaker plate closer to the hammer circle. Largeaccess doors provide entry for these adjustments. Thesecrushers accept feed sizes up to 30" (750mm).

NON-REVERSIBLE HAMMERMILLS

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This type of hammermill will crush material thatmight build up within other kinds of hammermills. Thiswould apply to any product that is very sticky or muddy,or that is simply too wet to be effectively crushed in othermills.

In place of the fixed breaker plate, a travelingbreaker plate revolves continuously and carries theincoming feed into the path of the hammers. Thisvirtually eliminates any chance for feed to build upoutside of the hammer sweep area. The combinedforces of crushed particle velocity and gravity arenormally sufficient to clear the product through themachine. However, if the feed is so sticky that it mayaccumulate, this machine can be equipped with an

additional traveling rear element which is self-cleaning.Both the traveling breaker plate and the

traveling rear element have a torque release mechanismthat allows the V-belts to go slack and the motor to shutoff in case of a jammed breaker plate.

Because this type of hammermill is usuallyoperated under extremely difficult conditions, the motordrives for the traveling breaker plate and for the rearelement are mounted on the mill itself, above theworking level. This arrangement is very compact andrequires minimum floor space.

Non-Clog Hammermills accept feed sizes up to 36"(900mm).

NON-CLOG HAMMERMILLS

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Coalpactors were originated by PennsylvaniaCrusher to crush coking coals and to produce anoptimum percentage of product below 1/8” (3mm), butwith a minimum amount of fines (100 mesh or smaller).Coalpactors are also used for crushing coal andpetroleum coke for fluid bed boilers which have similaroutput size requirements.

This crusher permits coke plant operators toobtain high stability coke from various grades of coal.When coke is produced from a blend of petrographicallydiffering coals, the coke strength is improved by controlof the minus 1/8” (3mm) pulverization.

A Pennsylvania Coalpactor is similar to animpactor. It has breaker plates that are fully adjustablefrom outside of the frame to enable operators to varythe degree of pulverization. This allows maintenance ofa uniform product size throughout the life of hammersand breaker plates.

The Coalpactor rotor may be run eitherclockwise or counter-clockwise to provide for equalwear on both hammer faces. This helps to extendhammer life and to reduce maintenance problems. Tofacilitate servicing, all internal parts of the machine arereadily accessible.

Pennsylvania Coalpactors have largelyreplaced other types of crushers for crushing cokingcoals because the Coalpactor will maintain ratedcapacity even when the coal is wet, and it is not affectedby uncrushables.

When used to crush fuel for fluid bed boilers,the FB-design Coalpactors use an extended crushingpath to further improve output size control.

COALPACTORS

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This is a special type of Impactor that takes largepieces of aluminum dross or slag and reduces the oxide, byimpact, to approximately 8" (200mm) and under. The impactfrees the more friable slag from the harder, uncrushable metal.Thus, the machine not only reduces the dross, but alsobeneficiates the aluminum.

As dross enters the feed hopper, it slides down into thepath of heavy rotating hammers. Upon impact with thesehammers, the dross is driven up against the breaker bars.Additional reduction also takes place as material ricochetsbetween the hammers and the breaker bars, until it is finallyswept from the crushing chamber. This machine alsoincorporates a protective device for uncrushables.

METALLIC SLAG CRUSHERSIn addition to the Aluminum Dross Impactor, Pennsylvania

Crusher also offers other crushers which are used for crushing dross orslag.

The Reversible Impactor (CF 9-50) was developed for reduction ofopen hearth, B.O.F. and blast furnace slag. This crusher takes 10" - 12" (250-300mm) slag and reduces it to a minus 2" - 3" (50-75mm) product size in onepass. In this crusher, the impact breaks the more friable oxides from themetallic particles. The metallic particles are then separated magnetically andthe oxide or slag body is used for aggregate.

Pennsylvania Jaw Crushers are used to crush residue materialfrom the zinc smelting process. The crushed material then goes back intothe system for reclamation of usable zinc.

Pennsylvania Jaw Crushers are also used to crush saltcake, which is a furnace slag containing a high amount of sodiumchloride. To retrieve particles of aluminum, the PennsylvaniaJaw Crusher reduces the salt cake to minus 5" - 6" (125 -150mm).

ALUMINUM DROSS IMPACTORS

CF 9-50 Reversible Impactor

Jaw Crusher

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Reversible Impactors are used for secondaryand tertiary crushing, and occasionally for primarycrushing. They are used for reduction of cement rock,gypsum, fertilizer, chemicals, lime and agriculturallimestone, lightweight aggregate, ceramics and othermaterials.

Reversible Impactors are normally recom-mended when certain requirements exist: high reductionratio (35:1 or greater), high capacity, cubically shaped,well-graded product, and minimum fines.

These crushers can be easily adjusted toproduce a wide variety of product sizes. For coarseroutput sizes, Impactors are operated at lower speeds.When finer output sizes are required, higher speeds areused. It is also possible to change product size bymaking adjustments to the breaker block assemblies.

Material drops through the centrally locatedfeed chute directly into the rotor, where it is struck by therotating hammers. The material then impacts againstthe breaker blocks and rebounds into the path of thehammers. There are no cage bars or screens,

therefore, impact and some shear are the methods ofreduction. The bottom of the crusher is entirely openand the sized material passes out freely.

When the product must be held to a specific topsize, the machines should be operated in a closed-circuit system. When operating in closed-circuit, the milldischarge is carried to external screens or classifiers forseparation, with the oversized particles being returnedto the impactor for further reduction.

The size of the feed may vary up to sizesproduced by primary crushers. In some instances,these crushers will handle material directly fromquarries or other sources.

Pennsylvania Crusher originated the ReversibleImpactor in order to eliminate manual turning ofhammers. The Reversible Impactor is symmetrical indesign, and by simply pushing the reversing button, theoperator can change the direction of the rotor,presenting a fresh hammer face to the feed.

REVERSIBLEIMPACTORS

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SMALL REVERSIBLE IMPACTORS

These smaller impactors have been designedfor specialized crushing requirements at relatively lowcapacities.

Typical applications for these units include:“green” brick, mill scale, foundry sand, gypsum,phosphate rock, flake frit, graphite ore, glass tubing, saltcake, brass skimmings and tungsten carbide chips.

For servicing, the frame section on both ends ofthe machine may be removed to expose the breakerblocks, liners and rotor. The liners are made of carbon-manganese steel and are renewable.

The upper breakerblocks are made of castalloy steel and are bothreversible and interchange-able. The lower breakerblocks are supplied in fixedor adjustable configuration.

These impactorsare offered in several sizes.

TWIN ROTOR IMPACTORS

The Pennsylvania Twin Rotor Impactor handleswet, sticky materials that would clog most othercrushers. It produces a maximum of fines and is widelyused in brick and clay plants as a secondary crusher. Itcan also be used as a primary tailings crusher.

The crushing action in Pennsylvania Twin RotorImpactors is accomplished solely by impact of the feedagainst two counter-rotating sets of manganese steelhammers. There are no impact blocks, screen bars orother stationary impact areas, and the product path isdirectly through the center of the crusher. This design

demands relatively little power and it facilitates crushingof wet, sticky materials.

The Twin Rotor Impactor has an inner lining,separated from the outer shell by a chamber or“plenum”. Hot waste gas can be directed into theplenum, heating the lining. This helps to prevent a majoraccumulation of material.

Twin Rotor Impactors are available in three sizes;the largest can accept feed sizes up to 14" (350mm).Normally these units are operated in closed-circuit. Eachrotor is driven by a separate motor.

SMALL REVERSIBLE IMPACTOR TWIN ROTOR IMPACTOR

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For crushing of hard, abrasive materials, JawCrushers are often preferred, since this type of machinewill crush virtually any mineral.

Jaw Crushers differ substantially from othertypes of crushers. There is no rotary motion in thecrushing cycle, and all crushing is done by compressionof the feed material between two massive jaws, which ineffect are a type of breaker plate. Jaw plates can beeither smooth or corrugated.

While one jaw is fixed, the other jaw pivots abouta top hinge. This moving jaw is shaped to move firmlyand squarely against the material, at 250 to 400 strokesper minute. There is no rubbing or grinding, onlycompression, which produces a generally cubical productwith minimum fines.

The moving jaw is so balanced that fully 95% ofthe drive motor power is used for crushing, while only5% of the power is needed to move the jaw itself. As aresult of this high mechanical efficiency, smaller motorsmay be used, keeping power costs down.

Behind the stationary jaw are shims, used tocompensate for plate wear and to adjust the closed sidesetting. For protection from uncrushables, there is alsoan automatic drive disengagement feature that actsinstantaneously on the moveable jaw assembly.

Pennsylvania Jaw Crushers accept feed sizesup to 48" (1200mm) and produce a nominal product sizeas small as 3/4" (19mm). Product size is determined bythe distance between the lower end of the jaws. Thisgap dimension may be adjusted by shims behind thestationary jaw assembly. These crushers may be choke-fed from hoppers or conveyors.

Jaw Crushers for Glass Cullet

The basic Jaw Crusher design is modified forglass crushing by changing to special corrugatedplates, called “cullet plates”, on both jaws. These culletplates meet and intermesh to provide completecrushing of the glass. The product is designated asglass “cullet”.

JAW CRUSHERS

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The Brad-Multi-Roll Crusher was introduced toproduce material with output smaller than 1/4" (6mm)while producing a minimum of extreme fines.

This produces a product having a very steepgradation curve, making it ideally suited for preparationof fuel and sorbents for fluid bed boilers and for otherapplications that require such a gradation.

This machine is capable of handling moistmaterials when operated in open circuit. Drying is usuallyrecommended when closed-circuit operation is needed tomeet a specific gradation curve.

The Brad-Multi-Roll Crusher is well suited toabrasive materials. To compensate for any reduction incharge level resulting from wear, additional charge can

simply be added. This greatly simplifies maintenance,and provides a machine with exceptionally highavailability.

For some closed-circuit applications, integralscreening can be accomplished. The great compact-ness of this design means that a smaller building isrequired, while minimizing the need for peripheralequipment. Optional sound housings can be providedto control noise emissions.

When compared with other machines thatrequire air classification to achieve specified productsizes, users of the Brad-Multi-Roll Crusher will enjoysignificant and continuing savings in power costs.

BRAD-MULTI-ROLL CRUSHERS

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CLINKER CRUSHERS

The Clinker Crusher is used for handling of bot-tom ash, though it can readily be configured to handleother materials.

It is now widely employed as a direct replace-ment for the most common makes and sizes of clinkergrinders. Its efficient design improves maintainabilityand increases component life, thereby reducing bothoperation and maintenance costs.

For example, the cast, high chrome rollsegments are reversible to maximize their wear life.These segments can also be changed out with the unitin place by means of a large door in the rear of theframe.

For retrofit, no changes to foundations areneeded under normal circumstances.

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SINGLE ROLL CRUSHERS

Single Roll Crushers are typically used as primarycrushers. A single roll crusher has a roll assemblyconsisting of a roll shaft and a fabricated roll shell withintegral fixed teeth.

In the single roll crusher, three different methodsof reduction occur: impact, shear and compression.

Entering the crusher through the feed hopper,the feed material is struck by the teeth of the revolvingroll. While some breakage occurs here by impact, therotation of the roll carries the material into the crushingchamber formed between the breaker plate and the rollitself. As the turning roll compresses the material againstthe stationary breaker plate, the teeth on the roll shearthe material.

Sized material falls directly out through thedischarge end of the crusher which is completely open.There are no screen bars, and consequently there is norecrushing of the sized materials, a factor that helps toreduce power demand while minimizing product fines.

The clearance between the breaker plate andthe roll determines the product size. This clearance isadjustable from outside the machine by a shimarrangement. Adding or removing shims causes theplate to pivot about its top hinge, moving it into or awayfrom the roll.

For protection against uncrushable debris, thebreaker plate assembly is secured with an automaticrelease device. As pressure from the uncrushable isexerted against the plate, the device allows the entirebreaker plate assembly to move away from the rollinstantly. The uncrushable drops clear of the machine bygravity, and the breaker plate assembly immediatelyreturns to its normal crushing position.

Pennsylvania Crusher Corporation buildsseveral types of Single Roll Crushers in a great numberof sizes and capacities, with product sizes ranging from3" (75mm) to 12" (300mm) depending on machine size.

Applications include petroleum coke, coal withrock, coal, aggregate, limestone, chemicals, phosphaterock, shale and many other materials.

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These are typically used in situations in whichfines are to be minimized. They are widely employed onfriable materials such as coal, lime, limestone, petroleumcoke, and chemicals.

As the two rolls rotate toward each other, thematerial is pulled down into the crushing zone where it isgrabbed and compressed by the rolls.

Product size is determined by the size of the gapbetween the rolls, and this gap can be changed to varyproduct size or to compensate for wear.

Since both rolls rotate at the same speed, thereis no relative motion between the two roll surfaces, andcrushing is primarily accomplished by compression.

Compression crushing is extremely efficient, asenergy is only used to crush those particles larger thanthe gap between the rolls. Fines are reduced becausealready sized material passes freely through the crusherwith no further reduction.

Usual feed sizes are up to 6" (150mm), thoughlarger feed can be effectively handled in certainapplications. Reduction ratios normally do not exceed 4to 1.

Protection from uncrushables is provided bymeans of a retractable roll assembly. It retracts instantlywhen an uncrushable is encountered, then reverts to itsoriginal position once the uncrushable has cleared thecrushing chamber with no stoppage of the crusher.

Pennsylvania offers Double Roll Crushers in anumber of sizes and roll tooth patterns.

DOUBLE ROLL CRUSHERS

Other tooth patterns also available.

ROLL TOOTH PATTERNS

TRAPEZOID SLUGGER TRAPEZOID SMOOTH

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FROZEN COALCRACKERS

This type of machine is basically a single rollcrusher. It differs from our other single roll crushers inthe drive mechanism.

Though it utilizes the basic single roll design andcrushing actions, this particular machine has anextremely wide feed opening which permits the use ofopen-throated hoppers to choke feed large lumps of coalinto the machine. It will reduce coal to a nominal 6" to 8"(150 to 200mm) product size.

Freezing of the coal can occur in railcars andstockpiles, causing stoppages in handling or conveying.These frozen coal lumps will often fall from conveyors orbecome wedged in hopper throats.

For this reason, Pennsylvania Frozen CoalCrackers have a low profile, so as to fit into existing

handling systems. The machine is often installed directlybelow the railcar delivery hoppers or at the outdoorstockpile.

The breaker plate may be backed off duringwarmer weather to permit coal to flow directly through theunit unhindered. If desired, the entire roll assembly canbe removed for warm weather operation withoutdisturbing the feed system in the Model FCC. The FCCRModel allows easier removal of the roll by a screwmechanism. The roll assembly is then stored on theframe, fully aligned and ready to be re-inserted whenfreezing conditions recur.

Model FCC

Model FCCR

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The Mountaineer Sizer crushes a wide variety ofmaterials. It incorporates all of the features needed todo a better job than ordinary sizers, for primary orsecondary sizing.

For example, it sizes very accurately, producesextremely low fines and operates at low speed. Suchlow speed also helps to extend component life. It alsouses relatively low horsepower, resulting in reducedequipment wear and energy costs as well as low noiselevels. Made in U.S.A., its construction is modular andemploys standard components, meaning thatmaintenance can be performed more quickly and at lesscost than others. Low headroom, as low as 40 inches,enables it to fit most plant layouts.

An extremely rugged, high capacity machine,its crushing chamber is lined with heavy duty liners, andall side liners are reversible. The sizing rolls are offeredin a variety of tooth patterns to suit the application.

The Mountaineer Sizer is offered in variouslengths, with capacity dependent on many factors, themost important of which is the output size. The sizersare direct driven through a gearbox, and a fluid couplingis provided for tramp iron protection.

MOUNTAINEER™ SIZERS

Wheels not shown

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POSIMETRIC FEEDERS

This unique feeder handles materials having anextraordinary range of characteristics, including wet, dry,lumpy, sticky, abrasive or granular. Virtually immune tojams, it will feed dry, light particles at 1,200 pounds perhour, or heavy sticky materials at 120,000 cubic feet perhour, with absolute consistency never before achieved inordinary feeders.

It delivers material with unvarying accuracy of upto 99.5 percent, with no need to recalibrate, unless thematerial changes. Regardless of moisture content, itdelivers a constant rate of bulk solid material; eachrotation delivers a fixed volume that cannot vary,meaning that it feeds at the desired rate, with no surgesand no partial feeding.

This feeder contains only a single moving part –the rotating duct. Because the feed material helps to

turn this duct, only a small motor, usually under 10 hp.,is required to drive it. Those factors result in very lowstress and exceptionally low maintenance. In addition,wear is negligible because there is almost no abrasiveaction of material against the working parts. Some unitshave been in service for up to ten years, withoutneeding a single replacement part.

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Printed in U.S.A. Bulletin 4050-D 00-3-03R-1M

600 Abbott Drive • Box 100 • Broomall, PA 19008-0100 U.S.A.Phone: (610) 544-7200 • Fax: (610) 543-0190

E-Mail: [email protected]

www.penncrusher.com

PennsylvaniaCrusher


®

Click on link below to obtain contact information for our company staffand for our sales representatives around the world. Application

engineering assistance is available upon request.

Requests for individual brochures on each of our crushers or feedersmay be sent to our e-mail address or by writing

or faxing to the address shown.

Handbook of Crushing

Documents

Transcript of Handbook of Crushing