Voc Control Devices

8/7/2019 Voc Control Devices

http://slidepdf.com/reader/full/voc-control-devices 1/66

VOC Controls 1/66 © Copyright Training 4 Today 2001 Published by EnviroWin Software LLC

VOLATILE ORGANIC COMPOUNDS

CONTROLS

CUSTOMIZED ENVIRONMENTAL

TRAINING




INSTRUCTOR

Insert Instructor Name Here




Define Ground Level Ozone.

Define VOCs.

Discuss VOC Content.

Discuss Transfer Efficiency (TE).

Discuss Different Types of Sprayers.

Discuss Operator Training.

Discuss Capturing Fugitive Emissions.

Discuss Destroying Fugitive Emissions.

Recommend Handling, Storage, and Disposal Procedures for

VOCs.

OBJECTIVES




GOALS

Understand the Definition Ground Level Ozone.

Understand the Definition of VOCs.

Understand What VOC content is. Understand Transfer Efficiency.

Be Familiar With The Different Types of Sprayers.

Understand the Importance of Operator Training.

Understand the Importance of Capturing Fugitive Emissions. Understand the Importance of Destroying Fugitive Emissions.

Be Familiar With Recommend Handling, Storage, and

Disposal Procedures for VOCs.




BACKGROUND In 1998, 61,234 industries reported a total of 7.3 billion

pounds of hazardous chemicals released to the air, land and

water in the United States.

EPA estimates that 85,300 tons of toxic emissions from

solvents are released to the atmosphere annually

Solvents contain Volatile Organic Compounds (VOCs) that

have been found to contribute to the formation of smog and

ozone

Fugitive Air Emissions Containing VOCs can have a

Detrimental Impact on Human Health and the Environment.




Supervisors

Facility Engineers

Maintenance Personnel

Department Managers

Building Occupants

Process Specialists Environmental and Safety Committees

LEARNERS




The goal of this course is to provide supervisors

with the tools needed to help control Volatile

Organic Compounds (VOCs) from becoming fugitiveemissions. It recommends practical, actions that can

be carried out by facility management, maintenance

personnel and building occupants. The course will

help you to integrate good VOC control management

activities into your existing organization and identify

which of your staff have the necessary skills to carry

out those activities.

OVERVIEW




WHAT THIS COURSE DOES NOT DO

The course is not intended to provide information to

install, repair, calibrate equipment or remove VOC

control devices. Nor is it intended to providealternative technologies or products that do not

contain VOCs. These specialties required training

beyond the intended scope of this course. Where

this expertise is needed, outside assistance should

be solicited.




CLEAN AIR ACT AMENDMENTS

(CAAA)

CAAA of 1990 - One of the 189 hazardous air pollutants that has been identified is Volatile OrganicCompounds (VOCs).




FEDERAL REGULATIONS

Pertinent Regulations:

40 CFR 59²National Volatile Organic Compound Emission

Standards For Consumer and Commercial Products

40 CFR 63 Subpart D²National Volatile Organic CompoundEmission Standards for Architectural Coatings

40 CFR 63 Subpart KK - National Emission Standards for thePrinting and Publishing Industry

40 CFR 60 Subpart RR - Standards of Performance for PressureSensitive Tape and Label Surface Coating Operations

40 CFR 60 Subpart FFF - Standards of Performance for FlexibleVinyl and Urethane Coating and Printing




GROUND LEVEL OZONE

Ground level ozone, commonlyreferred to as "smog," is the singlemost serious air quality challenge for

most urban areas

In 1990, six out of every ten Americans were living in an areaswhere ozone levels exceeded EPA'sair quality standards

This was the number 1 urbanpollutant




GROUND LEVEL OZONE

Ground level ozone is a complex problem that is difficultto control in part because it is not emitted directly byspecific sources

It forms in the air when there are chemical reactionsbetween two other pollutants nitrogen oxides (NOx) andvolatile organic compounds (VOCs) -- in the presence of heat and sunlight

Hotter temperatures accelerate ozone formation

Ozone at ground level is a major health andenvironmental problem

Ozone is beneficial substance in the stratosphere whereit shields the earth from the sun's harmful ultravioletradiation




WHAT ARE VOCs?

VOCs* (volatile organic compounds); smog-formers

VOCs are released from burning fuel solvents, paints

glues and other products used at work or at home

VOCs, in addition to ozone (smog) effects, can causeserious health problems such as cancer and other effects

In addition to ozone (smog) effects, some VOCs suchas formaldehyde and ethylene may harm plants andanimals




WHAT ARE VOCs?

All VOCs contain carbon (C), the basic chemicalelement found in living beings

Carbon-containing chemicals are called organic

Volatile chemicals escape into the air easily

Many VOCs are also hazardous air pollutants, whichcan cause very serious illnesses

EPA does not list VOCs as criteria air pollutants, butthey are included in this list of pollutants because effortsto control smog target VOCs for reduction




REDUCING VOCs

Non-attainment areas must reduceVOC emissions by 3% per year, untilthe standard is attained

The base year of measuring is 1990.

All but Marginal areas must reduceVOC emissions by 15% by 1996

After that point, the areas must

continue to reduce VOC emissions by3% annually




REDUCING VOCs

Purchase products with the lowest VOCconcentrations

Ensure there are high transfer efficiencies of theproduct to reduce waste and fugitive emissions

Collect and destroy fugitive VOC emissions




VOC CONTENT

Coatings consist of solids and solvents

Solvents lower the viscosity and act as the carrier for

the solids

Solvents also are used to dissolve the solid resin

Solvents evaporate from the coating before, duringand after application

Solvents include VOCs, water, and exempt solvents




VOC CONTENT

The VOC concentration does not change if youincrease the volume of mixed paint used, however, theVOC concentration does increase when adding VOC

solvents such as thinners or reducers

Manufacturers are currently being required by federalregulations to formulate paint to certain VOCspecifications, that when used, according to themanufacturer¶s recommendations, will meet VOCcontent limits

The VOC content is generally stated on the label or on the manufacturer¶s paint specification sheet




CALCULATING VOC CONTENT

Information is from a Material Safety Data Sheet for thiscoating:

If the coating weighs 10.4 pounds/gallon, and it contains

the following VOCs:Xylene 2% x 10.4 lb/gal = .21 lb/gal

Toulene 2% x 10.4 lb/gal = .21 lb/gal

MEK 6% x 10.4 lb/gal = .63 lb/gal

Mixed Aliphatics 10% x 10.4 lb/gal = 1.04 lb/galTOTAL 20% x 10.4 lb/gal = 2.09 lb/gal

2.09 lb/gal x 119.8 (g/L) (gal/lb) = 250 grams/Liter




TRANSFER EFFICIENCY

Transfer efficiency rates the ability of sprayequipment to put a coating on the parts being coatedrather than allowing it to escape as overspray or in

other forms of waste

If you spray 10 pounds of coating on uncoated partsand those parts gain two pounds as the result of beingcoated, you've achieved 20% transfer efficiency (TE)

In selecting new spray-painting equipment, 85% of industrial consumers rated transfer efficiency as

extremely or moderately important




SPRAYING

The major types of spray equipment in use today are asfollows:

Conventional Air-Atomize Guns

Airless and Air-Assisted Airless Guns

High-Volume, Low-Pressure Spray Equipment

Electrostatic Spray Equipment

Plural-Component Spray Equipment




CONVENTIONAL SPRAY GUNS

They have been around sincethe early part of this century

They emit a stream of coating

from a small opening in a fluidnozzle

The coating is broken up intotiny droplets by compressed air emerging from jets adjacent to the

fluid nozzle Relatively high air pressures atlow volumes will quickly atomizelarge amounts of coating





Advantages

In the hands of a skilled operator, produces smooth,reflective finishes

Can be used to coat almost any shape

Can apply paint at high production rates on partshanging from fast-moving conveyors

Are "user friendly." Most spray painters areexperienced in using them





Disadvantages

Very poor transfer efficiency

Wastes paint, increases cleanup costs, emitsmore VOCs




AIRLESS SPRAY GUNS

Similar to a garden hose

Airless paint guns pressurize coatings to 900-1200psi (or higher) and forces it through a nozzle

Unlike conventional air spray, there are no jets of atomizing air to break up the paint and propel it to thesurface

Atomization is dependent upon high fluid pressure




AIRLESS SPRAY GUNS

Advantages

In the absence of atomizing air, less overspray andbetter transfer efficiency

Can apply paint at high flow rates, resulting in abilityto meet high-production speeds




AIRLESS SPRAY GUNS

Disadvantages

Inability to break up paint into very fine droplets, thusproducing a coarser spray and a rougher finish

Nozzle wear from high velocities cause abrasivepigments in paints to wear nozzle openings morerapidly as they travel through the nozzle.

Danger of airless-injection injury




AIR-ASSISTED AIRLESS SPRAY

A hybrid of airless spray and conventional air-atomizespray, this kind of gun uses fluid pressures higher thanthose used in conventional air-atomize guns but lower

than those employed in normal airless spray Unlike normal airless guns, these guns do havecompressed air jets that supply atomizing air, but the air pressure is far lower than that used in conventional air-atomize guns

In operation, air-assisted airless guns provideatomization much better than is normal with airless

spray

Danger of airless injection is lessened, as is wear of fluid nozzles




AIR-ASSISTED AIRLESS SPRAY

The main reason for considering use of air-assistedairless spray is better transfer efficiency

Its softer spray also makes it easier to spray intorecesses

Both air-assisted and pure airless spray operate athigh fluid pressures and thus can use smaller-diameter fluid lines

This translates into paint and solvent savings




HVLP SPRAY

High-Volume Low-Pressure (HVLP) Spray is avariation of conventional air-atomize spray

The difference is that these guns are designed toatomize coatings using a high volume of air delivered at

low pressure

The lower pressure results in far less overspray and"bounce-back"




HVLP SPRAY

Advantages

Better transfer efficiency results in less coating wasteand lower cleanup costs

The exact TE depends upon the circumstances inyour installation the booth design, spray techniques, themix of parts, etc.

Operators used to conventional guns generally find it

easy to learn how to use HVLP




HVLP SPRAY

Disadvantages

Atomization may be insufficient to meet the strictestrequirements for smooth, fine finishes

May be difficult to atomize coating at sufficiently highrates to meet very high-production requirements




HVLP SPRAY

Disadvantages continued

Some problems in achieving proper atomization withHVLP may be caused by "starving" the spray gun for air

Causes of this problem include use of air hoses thatare too long or too small in diameter; use of too many"quick-disconnect" fittings; and use of low-performanceair compressors and air regulators

Any one of these factors may result in too little air being delivered to the air cap, causing poor atomizationfrom the gun




ELECTROSTATIC PAINTING

Electrostatic painting begins with a spray gun or other device to atomize a coating

The atomizing principle could be any of those

previously discussed conventional air-atomize, HVLP,or airless

The difference is that an electrostatic applicationdevice is equipped with a means of electrically chargingthe particles of a coating

A common method is to build in an electrode near thepoint where a coating is atomized

Parts are grounded, usually by hanging them on aconveyor securely connected to a ground





The result is that fewer of the coating particles arepropelled into space as overspray and more areelectrostatically guided to the surfaces of the parts

being coated Sprayed particles will even turn the corner and beattracted to the back side of a part if the velocity of theparticles causes them to initially travel past the partsbeing painted

Transfer efficiency is greatly improved withelectrostatic spray





Advantages

Higher transfer efficiency

Coverage of edgesUniformity of film thickness

Productivity - Electrostatic guns mounted onreciprocators are widely used to paint long runs of partsin high-production installations producing lower labor

costs





Disadvantages

Electrostatically charged particles seek out the

nearest grounded surface, if that happens to be theridge area of a sculptured part, the valley may bedifficult to reach

For this reason, manual touchup with non-electrostatic guns may be necessary

Changes appearance of metallics that areelectrostatically charged






Fire hazard - there is danger that a spark can occur,

igniting paints containing flammable solvents Safety - If operators are not careful to follow set-updirections, they can be electrically shocked

Ergonomics - Operators may find some guns moredifficult and more tiring to handle






Cleanliness - It's mandatory in order to achieve thebenefits of electrostatic application

Some coatings may require reformulation becausesome solvents are more conductive than others




ELECTROSTATIC ROTATIONAL

ATOMIZERS Rotary atomizers utilize centrifugal force rather thancompressed air or fluid pressure to atomize coatings

Discs

It is a spinning flat round disc with a hole in the center Feed coating through a hose so that it overflows throughthe hole and onto the spinning disc

Centrifugal force propels coating over the surface of thespinning disc until it flies off the edge

The coating atomizes as it is propelled through theatmosphere

Parts on hangers travel around the periphery of the discin an "omega loop," housed by a circular spray booth





ATOMIZERSBells

Electrostatic bells are similar in principle, except thatin this case the paint is fed through a hole at the closedend of the spinning bell-shaped atomizer

Centrifugal force propels paint from the edges of thebell

Bells may be mounted on reciprocators or on hand-

held guns.





ATOMIZERSHigher-Speed Rotational Devices

The latest bells and discs utilize higher rotationalspeeds, producing finer atomization, the ability to apply

higher-solids and waterborne coatings, and high transfer efficiency

These devices are often mounted on reciprocators invery-high-production installations

Less operator time is required in the disc application

But high-speed discs and bells also may have problemsin reaching into deep recesses

Some of the labor conserved by their use may berequired to hand-spray reinforce the areas of parts notproperly covered by the automatic spray




VOLTAGE-BLOCK SYSTEMS

Voltage-Block Systems

Waterborne coatings are widely used to lessen theVOC content of coating materials

To oversimplify, if water replaces some or all of theorganic solvents used in paints, the resultant coatingmaterial contains less VOC

Electrostatically applying waterborne coatings can bea problem

To circumvent this, manufacturers have developedincreasingly sophisticated "voltage-block" systems

Switching to waterbornes is now easier because of the new technologies available in voltage-isolatingsystems




PLURAL-COMPONENT GUNS

Plural-Component Guns continued

If the two components are mixed before entering apaint pump or pressure pot, the mixed material must besprayed promptly

It is said to have limited "pot life"

For this reason, spray guns have been developedthat bring each of the two components into the spray

gun through separate feed lines This remedies the "pot-life" problem, since mixingoccurs only at the moment before application




CO2 SPRAY

CO2 Spray

The most recent development in spray applicationequipment is built to spray coatings formulated withheated, compressed carbon dioxide

Carbon dioxide is a liquid and can be used as acoating thinner

Since carbon dioxide is naturally present in the

atmosphere and is not considered hazardous The system was developed and patented by UnionCarbide under the trade name "Unicarb"




HYBRIDS

Hybrids

There are numerous combinations of thetechnologies for spray painting

Such technologies as HVLP and air-assisted airless,already more efficient in raising TE, can be equippedwith electrostatics to further improve TE and lessenVOCs

But you have to test any system that appears to meetyour requirements in YOUR plant, while painting YOURmix of parts




PAINT HEATERS

Paint Heaters

Heat reduces the viscosity of paint

Heating paint before it is atomized makes it possibleto spray more viscous paint

Paint heaters are a well-established, viable means of lowering VOCs

If the coating formulation permits use of a paint

heater, it will keep viscosity more constant, improve TE,lower wear of equipment and improve finish quality andconsistency




CONVERTIBLE AIR-SPRAY GUNS

Convertible Air-Spray Guns

Some conventional air-sprayguns can be converted to HVLP

By inexpensively changing a fewcomponents of these guns, one canmove to HVLP without buying awhole new gun




OPERATOR TRAINING

Training operators of sprayequipment has always beenimportant, but it becomes evenmore so when one considers howoperators' techniques caninfluence TE

Operator training and annual re-training may be the bestinvestment you can make

Knowledgeable operators withgood spray techniques canmeasurably improve TE withoutchanging equipment




OPERATOR TRAINING

Pressures

Operators sometimes perceive that they can increaseair and fluid pressures to improve speed or reduce

orange peel Had they used the right air caps and fluid tips theymight have applied a smoother finish at lower fluid andair pressures

As much as 20% of a coating applied can be wasted

by too-high fluid and air pressures Use the lowest pressures consistent with finishquality and productivity




OPERATOR TRAINING

Exhaust Rates

In trying to improve transfer efficiency plant engineersmust set air-exhaust rates in spray booths to the lowest

consistent with operator safety and comfort

Too-high rates can pull more coating onto air-exhaustfilters than is being applied on parts being coated

OSHA regulations specify minimum flow rates and

you should aim to be close to these rates




OPERATOR TRAINING

Gun Handling

A well-trained operator holds the gun perpendicular tothe surface being coated, at a distance of six to eight

inches

Avoid "arcing" (holding the gun at less than a 90-degree angle to the surface)

Good operators move the spray gun toward the

surface to be coated before triggering As they reach the end of the surface being coated,they release the trigger to stop coating flow




OPERATOR TRAINING

Gun Handling continued

Manufacturers of equipment have been paying muchmore attention to ergonomic design

Companies using ergonomically designed gunsreport not only greater worker satisfaction and higher-quality finishes, but actual improvements in TE

A competent operator learns how to overlap hisstrokes to apply a smooth finish without excessive

thickness Your equipment and coating suppliers can help youwith operator training and tell you where to find trainingcourses for your operators




FUGITIVE VOC EMISSIONS

State permits will often dictate either "capture efficiency,""overall VOC reduction efficiency," or both

VOC Reduction can be expressed in the following way:

VOC Reduction = VOC Capture x VOC DestructionVOC Capture = % of the VOC emissions that is exhaustedto the VOC control

VOC Destruction = % of the VOC emissions that isexhausted to VOC control that is destroyed

Example:VOC Destruction for Control Device = 95%VOC Capture Rate = 90%VOC Reduction = 0.95 x 0.90 = 0.855 or 85.5%




TOTAL ENCLOSURE

EPA Guidelines for "TOTAL ENCLOSURE"

1. VOC sources not close to indraft openings.

2. Minimum openings in room of less that 5% of total

enclosure surface area.3. Minimum indraft air velocity of 200 fpm.

4. Access doors and windows closed during routineoperation.

5. All exhaust points must be directed to a controldevice.

With "total enclosure," EPA will assume 100% of totalcapture under these guidelines.




CAPTURING FUGITIVE VOC

EMISSIONSThe kinds of equipment needed to capture and conveythe waste gas to a control device are:

(1) hoods - used to capture the emissions at the source

(2) ductwork- to convey them to the control device

(3) stacks - to disperse them after they leave the controldevice

(4) fans - to provide the energy for moving them through

the control system




CONTROL DEVICES

The principle devices are:

Thermal Oxidation

Catalytic Oxidation

Condensation

Carbon Adsorption




THERMAL OXIDATION

Thermal oxidizers are control devices in whichsolvent-laden air is preheated and then passed to acombustion chamber

In the combustion chamber, volatile organics in theinlet air stream are ignited and combusted to carbondioxide and water

The two main types of thermal oxidizers arerecuperative and regenerative

Thermal oxidizers device efficiencies range from 98to 99 percent




CATALYTIC OXIDATION

Catalytic oxidizers, like thermal oxidizers, are controldevices in which solvent-laden air is preheated and thenpassed to a combustion chamber

In the combustion chamber, volatile organics in theinlet air stream are ignited and combusted to carbondioxide and water

In the presence of a catalyst, combustion will takeplace at a lower temperature than that required for thermal oxidizers

The catalysts, supported on ceramic or metallicsubstrates, are metal oxides or precious metals

Catalytic oxidizers can achieve control deviceefficiencies of 95 to 99 percent




CONDENSATION

Condensation is a control technique in which one or more volatile components of a solvent-laden air streamare separated from the remaining vapor throughsaturation followed by a gas-to-liquid phase conversion(i.e., condensation)

The recovered organic components can be reused or sold

Refrigeration is often employed to obtain the lowtemperatures required for acceptable removalefficiencies

Removal efficiencies obtained by condensers usuallyrange from 50 to 90 percent.




ADSORPTION

Adsorbers typically use activated carbon as theadsorptive material

Adsorber beds are typically operated in parallel sothat when the adsorption capacity of one bed isexhausted, it can be removed from service and asecond adsorber bed can be put into service

Carbon adsorption systems can achieve control

device efficiencies between 95 and 99 percent.




HANDLING, STORAGE AND

DISPOSAL OF VOCsHandling ±

Reduce spills and clean up spills immediately

During atomized cleaning of a spray gun, the

cleaning solvent must be directed into a waste container fitted with a capture device

Storage -

Store all VOCs and materials impregnated with VOCsin closed containers

Disposal -

Handle used VOCs as hazardous waste and alwayskeep waste VOCs in closed containers




Remember, You Control Your Facility or Area!

Review Procedures W ith Them Before Starting the Job!

Ensure They Are Properly Trained!

Determine Their Environmental Compliance Record!

Determine Who Is in Charge of Their People!

Determine How They Will Affect Your Facility¶s

Environmental Compliance!

TIPS FOR USING CONTRACTORS



THE IMPORTANCE OF A

CLEAN ENVIRONMENT

³I would ask all of us to remember

that protecting our environment is

about protecting where we live andhow we live. Let us join together to

protect our health, our economy,

and our communities -- so all of us

and our children and our

grandchildren can enjoy a healthyand a prosperous life.´

Carol Browner

Former EPAAdministrator

Voc Control Devices

Documents

Transcript of Voc Control Devices