Experimental study of cyclone seperators as combustor 1

Experimental study of cyclone separators as combustor

1

Contents Acknowledgment ………..…………………………………………………...4

Abstract……………………………………………………………………….5

Cyclone separators ................................................................................ 7

Combustion ........................................................................................... 8

Combustion triangle ............................................................................. 8

Objective of combustion ................................................................ 9

Types of combustion ...................................................................... 9

Flame .................................................................................................. 10

Flame definition ........................................................................... 10

Flame temperature ........................................................................ 10

Types of flame .............................................................................. 10

Flame stability .............................................................................. 11

Biomass fuel ....................................................................................... 14

Definition ...................................................................................... 15

Biomass fuel ................................................................................. 15

Biomass power ............................................................................. 15

Chemical composition .................................................................. 16

Biomass is a renewable source of fuel to produce energy for some

reasons 16

Biomass Energy in Egypt ............................................................. 16


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Definition: ........................................................................................... 18

How It Works: .................................................................................... 19

General Types of cyclone ................................................................... 20

Classification of cyclone according to design .................................... 21

Soviet type .................................................................................... 21

Stairmand design .......................................................................... 26

The advantages of the design ............................................................. 28

Effectiveness: ...................................................................................... 29

Advantages and disadvantages of cyclone ......................................... 29

Efficiency ............................................................................................ 30

Air calibration ..................................................................................... 32

Air calibration steps ..................................................................... 32

Fuel calibration ................................................................................... 35

LPG fuel calibration ..................................................................... 35

Experimental test rig ........................................................................... 38

Cyclone separator system: .................................................................. 40

Airline arrangement: .......................................................................... 41

Combustion system ............................................................................. 42

Combustion system components .................................................. 42

Feeding system ................................................................................... 43


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Instruments ......................................................................................... 44

Thermocouple ............................................................................... 44

Rotating vane Anemometer .......................................................... 44

Troubleshooting .................................................................................. 45

Cold condition .................................................................................... 48

Combustion condition......................................................................... 50

Conclusion from cold condition: ........................................................ 53

Future work ......................................................................................... 53


4

ACKNOWLEDGMENTS

At first and forever we thank ALLAH who helped us to finish this

work.

We are highly indebted to supervisor Prof. Dr. Mohamed Atteya

Okeily and Dr .Eng. Nasser Shelil for their guidance and constant

supervision as well as providing necessary information related to the

project.

Also, we would like to express our gratitude towards Eng. Ahmed

Gharib yousry for his, technical support and helping as.

Special gratitude and thanks go to our parents, whole family and

friends.


5

Abstract

The objective of our project is the experimental study of separator as

a combustor.

We designed a separator to give us maximum efficiency of

separation

(LPG) is used as a primary fuel to start the combustion and then burn

sawdust as a secondary fuel, Traditional fuel line system used to

supply LPG, sawdust is used as biomass fuel, we used specified

feeding system for biomass fuel (sawdust) and we designed a burner

to achieve flame stabilization.

Thermocouple type B (platinum / rhodium) is used for measuring hot

gases temperature to help us drawing temperature distribution inside

cyclone.

Rotating vane anemometer is used to measure velocity of air and LPG

to make calibration.

We preformed experiments in cold and hot condition

Cold condition

The particles of sawdust are separated from the air stream

through cyclone by gravity and centrifugal force.

Combustion condition

We succeeded to burn Sawdust (600 µm) and draw radial temperature

distribution.


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INTRODUCTION


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Cyclone separators

Cyclones are mostly used for removing industrials dust from air or process

gases. They are the principal type of gas-solid separator

Most common form of particulate removal gas is spun rapidly – heavier

particulate matter to collect on outside of separator by centrifugal force, where

it is collected and removed.

Fig. 1-1 Cyclone separator


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Combustion

Study of combustion process in all combustion systems is one of the most

Important and complex problems.

Combustion or burning is the sequence exothermic chemical reaction between

a fuel oxidant Accompanied by the production of heat and conversion of

chemical species.

The release of heat can result in the production of light in the form of either

glowing or aflame.

Combustion triangle

Fig. 1-3 Combustion triangle

Fig. 1-2 Combustin process


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The combustion triangles may be also consisting of:-

• Combustible mixture of air and fuel

• Ignition source

• Flame holder

In a complete combustion reaction, a compound reacts with an oxidizing

element, such as oxygen.

Objective of combustion

The objective of combustion is to retrieve energy from the burning of fuels in

the most efficient way possible .to maximize combustion efficiency ,it is

necessary to burn all fuel material with the least amount of Loses . The more

efficiently fuels are burned and energy gathered, the cheaper the combustion

process becomes.

Types of combustion

The continuous combustion

The continuous combustion engine is characterized by a steady flow of fuel and

oxidizer into the engine. A stable flame is maintained within the engine (e.g.,

jet engine).

The intermittent combustion

The intermittent combustion engine is characterized by an unsteady flow of fuel

and air into the engine. Non continuous flame is maintained within the engine

(i.e. Internal combustion engines).


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Flame

Flame definition

A flame is the visible light emitting, gaseous part of fire. it is caused by highly

exothermic reaction (for example combustion ,a self-sustaining oxidation

reaction ) taking place in a thin zone .

Flame temperature

Fig. 1-4 Flame temperature distribution

Types of flame

Diffusion flame

In combustion, a diffusion flame is a flame in which the oxidizer combines with

the fuel in the combustion zone. As a result, the flame speed is limited by the

rate of diffusion. Diffusion flames tend to burn slower and to produce more

soot than premixed flames because there may not be sufficient oxidizer for the

reaction to go to completion.

Fig. 1-5 Diffusion flame


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Premixed flame

Flame in oxidizer has been mixed with the fuel before it reaches the flame front.

This creates a thin flame front as all of the reactants are readily available. If the

mixture is rich, a diffusion flame will generally be found farther downstream.

Fig. 1-6 premixed flame

Flame stability

Flame stabilization is of fundamental importance in the design.

It is found that, the flow velocity and burning velocity are the most important

factors that the flame stabilization depends on. The burning velocity should be

equal to the flow velocity for a stationary flame front.

Parameters Influencing Flame Stability

There are many factors that affecting on the stabilization of flames are

Described here, these include:

a) Blockage effect

If flame holder is located in a duct, which is the normal case, then an additional

parameter controlling its stability characteristics is known as the blockage ratio,

(BR). This is defined as the ratio of the area of projected flame holder to the


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cross sectional area of the duct. All stability theorems show that stability limit

is widened as the characteristic dimension of the flame holder increases.

b) Flame holder size

An increase in flame holder size improves stability by extending the residence

time of reaction in the recirculation zone.

c) Flame holder shape

The shape of flame holder affects its stability characteristics, which influences

the size and shape of the wake region.

d) Fuel type

The fuel type has an effect on stability limit as for kerosene type fuel, it’s found

that combustion can be sustained at leaner mixture strengths with fuels of lower

specific gravity. The paraffin fuels will operate at lower fuel air ratio than

aromatic fuels.

The stability is further improved with:

1. The increase in fuel volatility.

2. Finer atomization and reduction of the mean drop size of fuel.

e) Stream velocity

Any increase in stream velocity invariably has an adverse effect on flame

stability. Any increase in velocity reduces the range of mixtures strengths over

which combustion is possible and increases the weak extinction limit.

f) Pressure

The increase in the reactants pressure always improves flame stability. The

studies performed, by several investigators on bluff body flame holders in can-

type, burners, and stirred reactors have fully confirmed the beneficial effect of


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increased pressure in extending the range of stable operating conditions. For

the gases mixture, the increase in the pressure expands the stability loop by

enhancing the blowout velocity, especially for rich and near stoichiometric

mixture.

Flame Stabilization Methods

Free jets flames are hardly stable, so some mechanisms are needed to enhance

the flammability limits of the flame such as using a bluff body, a swirler.

1- Flame stabilization by using a bluff body

Bluff bodies are used to stabilize flames in high velocity flow in variety of

propulsion and industrial combustion systems.

The usual shapes of the bluff bodies used are cylindrical rods, rectangular discs,

baffles, cones or “vee” gutters which produce in their wake a low velocity

recirculated flow in which combustion can be initiated and maintained. The

propagation of flame to other regions is rendered possible by the transport of

heat and radicals from the boundaries of the re-circulation zone to the adjacent

fresh mixture.

Fig. 1-7 Different shapes bluff body


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2-Flame stabilization using a swirler

A swirler is a number of curved swirl vanes have different angles normally 30,

45 and 60 degrees, which promotes the formation of recirculation zone and this

is the essential mechanism for flame stabilization. Swirling flow can be

produced either by tangential jet injections or by vane swirlers. The swirl angle

determines the size and the strength of the recirculation zone and most of flame

properties.

Fig. 1-8 Air swirler

Biomass fuel

Fig. 1-9 Biomass fuel


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Definition

Biomass is fuel that is developed from organic materials, a renewable and

sustainable source of energy used to create electricity or other forms of power,

or Biomass is biological material derived from living, or recently living

organisms. In the context of biomass for energy this is often used to mean plant

based material, but biomass can equally apply to both animal and vegetable

derived material.

Biomass fuel

Biomass from plants or animal origin are directly burnt for cooking and other

purposes. Agricultural wastes are converted to energy which can meet the

demand for energy in rural sector.

Biomass power

Fig. 1-10 Shape of burning biomass

Biomass power is carbon neutral electricity generated from renewable organic

waste that would otherwise be dumped in landfills, openly burned, or left as

fodder for forest fires.


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When burned, the energy in biomass is released as heat. If you have a fireplace,

you already are participating in the use of biomass as the wood you burn in it

is a biomass fuel.

In biomass power plants, wood waste or other waste is burned to produce steam

that runs a turbine to make electricity, or that provides heat to industries and

homes. Fortunately, new technologies — including pollution controls and

combustion engineering — have advanced to the point that any emissions from

burning biomass in industrial facilities are generally less than emissions

produced when using fossil fuels (coal, natural gas, oil). ReEnergy has included

these technologies in our facilities.

Chemical composition

Biomass is carbon based and is composed of a mixture of organic molecules

containing hydrogen, usually including atoms of oxygen, often nitrogen and

also small quantities of other atoms, including alkali, alkaline earth and heavy

metals.

Biomass is a renewable source of fuel to produce energy

for some reasons

Waste residues will always exist – in terms of scrap wood, mill residuals and

forest resources; and properly managed forests will always have more trees,

and we will always have crops and the residual biological matter from those

crops. ReEnergy Holdings is an integrated waste fuel/biomass renewable

energy company. Our facilities collect, process and recycle items for use as

fuel, as well as green energy facilities that create power from that waste.

Biomass Energy in Egypt

In Egypt the total biomass resources potential reaches 40 million Ton / year .


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CYCLONE SEPARATOR


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Definition:

Cyclone separators have been used in the United States for about 100 years,

and are still one of the most widely used of all industrial gas-cleaning devices.

The main reasons for the wide-spread use of cyclones are that they are

inexpensive to purchase, they have no moving parts, and they can be

constructed to withstand harsh operating conditions.

Fig. 2-1 Cyclone separator

Cyclone separators or simply cyclones are separation devices that use the

principle of Gravity to remove particulate matter from flue gases.

It is important to note that cyclones can vary in their size. The size of the

cyclone depends largely on how much flue gas must be filtered, and thus larger

operations tend to need larger cyclones.

http://energyeducation.ca/encyclopedia/Inertia

http://energyeducation.ca/encyclopedia/Particulate_matter

http://energyeducation.ca/encyclopedia/Gas


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For example, several different models of one cyclone type can exist, and the

sizes can range from a relatively small 1.2-1.5 meters tall (about 4-5 feet) to

around 9 meters or about 30 feet (which is about as tall as a three story

building!).

How It Works:

In a cyclone separator, dirty flue gas is fed into a chamber. Inside this chamber

exists a spiral vortex, similar to a tornado.

The lighter components of this gas have less inertia, so it is easier for them to

be influenced by the vortex and travel up it. Unlike these particles, larger

components of particulate matter have more inertia and are not as easily

influenced by the vortex.

Fig. 2-2 Particles move through a cyclonic separator


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Because these larger particles have difficulty following the high-speed spiral

motion of the gas and the vortex, the particles hit the inside walls of the

container and drop down into a collection hopper.

Most cyclones are built to control and remove particulate matter than is larger

than 10 micrometers in diameter.

General Types of cyclone

Single cyclone separator

Horizontal cyclone separator

Vertical cyclone separator

Multiple cyclone separator

Fig. 2-4 Vertical cyclone Fig. 2-3 Horizontal cyclone


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Fig. 2-5 Multiple cyclones

Multiple cyclones are devices that consist of two or more cyclones which the

outlet cleaned air from the first cyclone is the inlet to the next cyclone etc.

Classification of cyclone according to design

Soviet type

Soviet type І

This type of cyclone combustors is used for high calorific value fuels

sometimes containing large quantities of volatile matter and where slag and ash

generation and removal are not a serious problem

With large stability limits, and large turndown ratios we will have low pollution

combustors, simple changes to flow aerodynamics in this type of cyclone


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combustor will achieve a large changes in the flow patterns regions of mixing

recirculation zones, and turbulence distribution.

Swirl number

The swirl numbers in cyclone combustors are appreciably higher than for the

corresponding swirl burners typically the range of swirl numbers lie in

between 3 and 20.In this type the swirl number is lie between 3< S < 11.

Design limitations

For main cyclone diameter D=30cm

Fig. 2-6 type I cyclone combustor


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Design limitations


Fig. 2-7 type I combustors

Table 1 soviet type I design

Soviet type І design 1. C

yclone diameter D = 30 cm

2. C

yclone diameter/Cone-tip

diameter

3. r

atio

D/Dc From 0.4 to 0.7 Dc=20cm

Cyclone length / cone- tip

diameter ratio L / Dc From 1.0 to 3.0 L= 60cm

No. of tang. inlets At least 2 inlets

Swirl number From 2 to 11

Fuel entry Usually tangential


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Soviet type ІІ

This type of cyclone combustors operates favorably at high swirl numbers and

is used for high ash content fuels when problems due to slag formation and fly

ash are of concern. This type of cyclone combustors is amore modification of

standard cyclone where burners have been substituted for tangential inlets.

Swirl number

The swirl numbers in cyclone combustors are appreciably higher than for the

corresponding swirl burners typically the range of swirl numbers lie in

between 3 and 20.In this type the swirl number is lie between 8< S < 20.

Fig. 2-8 type II cyclone combustor


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Design limitations


Fig. 2-9 type II cyclone combustor

Table 2 soviet typeII design

Soviet type ІІ design

Cyclone diameter D = 30 cm

Cyclone diameter/Cone-tip

diameter

ratio

D/Dc From 0.4 to 0.5 Dc=15cm

Cyclone length / cone- tip

diameter ratio L / Dc

From 1.0 to

1.25 L= 20cm

No. of tang. inlets Often only 1 sometimes up to 4

Swirl number From 8 to 20

Fuel entry Usually tangential


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Stairmand design

Stairmand cyclone was designed in 1951. It is one of the standard cyclones, and

is commonly used, this design and the listed below designs have the same

problem of high pressure loss and low collection efficiency.

Fig. 2-10 Stairmand cyclone


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This figure illustrate the dimensions of the cyclone. Which is used

Fig. 2-11 dimensions of the cyclone


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The dimensions for stairmand cyclone design are as follow:-

Table 3 The dimensions for stairmand cyclone

The advantages of the design

Lower pressure drop through the cyclone.

High collection efficiency.

Higher tangential velocity.

Good vortex due to optimized inlet dimensions.

Good performances at charge.

Cyclone diameter D = 30 cm

Inlet height a 0.618 D 18.9 cm

Inlet Width b 0.236 D 5.2 cm

Exhaust pipe diameter Dx 0.622 D 19 cm

Cylindrical part height h 1.618 D 49.4 cm

total height ht 4.236 D 129.2cm

Cone-tip height Ld 0.625 D 19.1 cm

Vortex finder depth S 0.62 D 18.9 cm

Exhaust pipe length Le D 18.9 cm

Cone-tip diameter Dd 0.382 D 11.7 cm


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Effectiveness:

Cyclone separators are generally able to remove somewhere between 50-99%

of all particulate matter in flue gas. How well the cyclone separators are

actually able to remove this matter depends largely on particle size. If there is

a large amount of lighter particulate matter, less of these particles are able to be

separated out. Because of this, cyclone separators work best on flue gases that

contain large amounts of big particulate matter.

The removed particulate matter is collected when dry, which makes it easier to

dispose of. Finally, these units take up very little space.

Advantages and disadvantages of cyclone

Advantage Disadvantage

Low capital cost High operating cost due to pressure

drop.

Ability to operate at high temperature Low efficiencies ( particularly for

small particles )

Can handle liquid mists. Unable to process (sticky materials)

Can handle dry materials.

Low maintenance requirements (no

moving parts).

Table 4 Advantages and disadvantages of cyclone


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Efficiency

The overall collection efficiency is defined as, in a time interval the ratio

between the mass of solids collected by the cyclone and the mass flow rate of

incoming solids

Cyclone efficiency = 𝐨𝐮𝐭𝐥𝐞𝐭 𝐦𝐚𝐬𝐬

𝐢𝐧𝐭𝐥𝐞𝐭 𝐦𝐚𝐬𝐬


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Calibration


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Air calibration

Calibration process means to find the relation between water head measured by

manometer installed between two sides of an orifice in the air duct and the mass

flow rate passes through this orifice, in order to do this the following steps will

be taken.

Air calibration steps

1. Turn the air blower on and adjust the air valve to get a suitable

manometer reading (∆ℎ𝑤𝑎𝑡𝑒𝑟) to start with.

After ensuring that the manometer reading is stable, measure the air velocity in

the air duct by means of vane anemometer as shown in figure (3.1) and figure

(3.2) respectively.

For every annuals area of the air duct, it will be a different air velocities because

the velocity profile distribution (𝑣1, 𝑣2, 𝑣3, … . 𝑒𝑡𝑐 ) are obtained at different

values of duct radiuses (𝑟1, 𝑟2, 𝑟3, … . 𝑒𝑡𝑐 ).

Fig. 3-1 rotating vane anemometer

Values of air duct radii and divided cross section areas


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𝑅1 𝑅2 𝑅3 𝑅4

1.5 cm 3.5 cm 5.5 cm 7.5 cm

𝐴1

=𝜋

4∗ (𝑑1

2)

𝐴2

=𝜋

4∗ (𝑑2

2 − 𝑑12)

𝐴3

=𝜋

4∗ (𝑑3

2 − 𝑑22)

𝐴4

=𝜋

4∗ (𝑑4

2 − 𝑑32)

7.07 𝑐𝑚2 31.41 𝑐𝑚2 63.62 𝑐𝑚2 113.09 𝑐𝑚2

Fig. 3-2 air duct divided cross section

2. Calculate discharge in each annuals area by using the equation:-

𝐐𝐢 = 𝐀𝐢 × 𝐕𝐢

3. Calculate the total discharge for the whole air duct by using the following

equation:-

𝐐𝟏 = 𝐐𝟐 + 𝐐𝟑 + 𝐐𝟒 + … …

4. Measure the air temperature by using thermometer installed in a hole in the

air duct to obtain the air density from the relation:-

ρ = 𝑷𝒂𝒃𝒔 / RT

𝑃𝑎𝑏𝑠 = 𝑃𝑎𝑡𝑚 + ρg∆h

Where:


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ρ: density of air in Kg/𝑚3

P: absolute air pressure in Pascal

R: air constant which equals 287 J/Kg K

T: temperature of air in K

∆h: head difference in Cm of water

5. By using the following equation we obtain the mass flow rate of air.

𝐦. = 𝛒 × 𝑸

6. Change the air duct valve opening which leads to change in the water head

difference in the manometer, and then obtain the relation between air mass flow

rate passes through the orifice and the pressure head difference on the orifice

side.

7. By plotting those values of head difference in Cm of water and mass flow

rate of air in g/sec we get the air calibration curve shown in figure (3.3).

Fig. 3-3 Air calibration curve


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Fuel calibration

LPG fuel calibration

The following steps would be taken:-

1- Connect LPG fuel cylinder to a pressure gauge.

2- Open the fuel cylinder main valve, then use the fuel regulator to control fuel

flow rate and adjust the fuel pressure (P) at certain value.

3- Obtain the fuel velocity (𝑣𝑢)using the vane anemometer

4- Obtain the fuel flow rate (Q) from the equation:-

𝐐 = 𝐀𝟐 ∗ 𝐕𝐮

𝐀𝟐: Area of velocity anemometer, 𝐕𝐮: fuel velocity

5- Obtain the fuel temperature (T) from the thermometer.

6- Obtain LPG constant (R) from the following equation:-

𝑹 = (𝐑𝐮/𝐌)

7- Obtain the fuel mass flow rate (𝐦𝐟𝐮𝐞𝐥) from the equation:-

𝐦𝐟 = 𝛒 ∗ 𝐐 = (𝐏𝐚𝐛𝐬/𝐑𝐓) * Q

𝐏𝐚𝐛𝐬 = 𝐏𝐚𝐭𝐦 + 𝐏𝐠

8- Change the fuel pressure (P) then get fuel mass flow rates at the new fuel

pressure values.

9-Draw the LPG fuel calibration curve to get its mass flow rate using pressure

as shown:


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The LPG having a volumetric composition analysis of:

Composition Propane Propylene Butane Iso-butane Methane

Vol (%) 90 5 2 1.5 1.5

HHVv(Mj/K

g)

46.296 45.277 44.862 20.094

For all LPG fuel the higher heating value is 46.607 Kj/Kg.

And its density is 1.923 g/gal.

Fig. 3-4 Fuel calibration curve


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EXPERIMENTAL TEST

RIG


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Experimental test rig

This chapter explain most of the parts in the device and show the function of

each component like (air lines arrangement , fuel lines arrangement , cyclone

body ,burner , etc.).

Fig. 4-1 Cyclone separator and combustor


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Fig. 4-2 cyclone separetor

No. Name

1 Air blower

2 Air control valve

3 Air orifice

4 Hopper

5 Burner

6 Cyclone chimney

7 Cyclone cylinder

8 Collecting box


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Cyclone separator system:

Fig. 4-3 cyclone design

Lc Collecting box length

d Collecting box chimney diameter

De Diameter of exit

h Length of cylinder

Do Diameter of cylinder

H Cyclone length

a Length of dust inlet

b Width of dust inlet

Dv Diameter of vortex finder

Lv Length of vortex finder


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Chimney: Is used to take out smoke from cyclone separator.

Vortex finder: The part in which the air and saw dust inter the cyclone are

crashed then they go to walls and rotate due to centrifugal force.

Cyclone body: It is used to separate solid particles from combustion products

flow of saw dust.

Collecting box and its chimney: It is used to collect solid burned particles

which are separated in cyclone body. And the chimney is used to take out

smoke from burned particles in collecting box.

Airline arrangement:

Fig. 4-4 airline arrangement

No. Name

1 Air blower.

2 Air line.

3 Butterfly control valve.

4 Air orifice.


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Combustion system

Fuel flow from LPG cylinder through fuel valve which controls fuel flow rate

then passes through orifice which makes pressure difference to indicate flow

rate then passes through fuel line to the burner where fuel and air burn to make

diffusion flame.

Air flows through airline and crashes into the bluff body making circulation

zone where fuel flows from nozzle and mixes with air to burn together with a

stable flame.

Fig. 4-5 Design of burner with bluff body

Combustion system components

LPG cylinder

Fuel control valve

Fuel orifice

Fuel line

Fuel nozzle(1mm diameter)

Bluff body(5cm disc)

Combustion chamber

C.C. cooling jacket


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Feeding system

The design of the feeding system can be used for feeding many types of

biomass fuel.

Sawdust is the biomass fuel used and separated in many different diameters by

using لتدرج الحبيبى بأستخدام المناخل(جهاز ا ) and the hopper is fitted with inlet of

screw pump and is used as a biomass fuel tank with the screw pump which is

driven by electrical motor to make a continuous feeding of sawdust in the

system.

The screw pump draws sawdust from the hopper to the air flow line.

Fig. 4-6 feeding system

Electrical motor(1500 rpm)

pulley

Belt

Hopper

Screw pump


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Instruments

The instruments are the devices which are used to measure the parameters

needed in the experimental study (temperature, pressure, flow velocity, etc.)

Thermocouple

Thermocouple type B (Platinum Rhodium-30%/ Platinum Rhodium-6%)

The thermocouple range is (0 C to 1700 C)

It is used to measure the temperature of combustion products circulated in the

cyclone body. )radial and axial).

Rotating vane Anemometer

The device is used to measure the velocity of air and fuel flow.

Fig. 4-9 Rotating vane anemometer

Fig. 4-8 Thermocouple Fig. 4-7 avometer


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Troubleshooting

Problems Remedies

Design of burner at first time

the flame was cut-off because

there was no flame stabilizer.

We used bluff body to hold

the flame (make flame stable).

Fitting the burner in the air

lines.

We designed new flanges and

welded it in the air lines.


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Leakage in the cyclone water

jacket.

Overheating of combustion

zone.

We solved the problems by arc

welding.

We made new water jacket for

combustion zone.

Due to high pressure (back

flow) the sawdust was comes

out from the feeding system.

We replaced the old feeding

system by screw pump driven

by large electrical motor (1500

rpm & 1 hp).


47

RESULTS


48

In this chapter we will use sawdust for our experiments

We have two methods for separations

Cold condition

We used four diameters for sawdust 6mm, 5mm, 4mm and 600µm. The

maximum efficiency of separation occurs when using the diameter of 6mm

(because large particles have large gravity force).

Combustion condition

We used one diameter for sawdust (600µm).

Cold condition

Sawdust is separated without combustion.

For diameter of 6mm, we found that the maximum efficiency of separation

occurs when the vortex finder (L) equals 20cm. and the minimum efficiency

occurs when (L) equals 10cm

Fig. 5-5-1 Results of cold separation of 6mm-saw dust


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For the diameter of 4mm, the maximum efficiency of separation at finder length

(L) is 20cm and 30cm is the same.



50

For diameter of 600 µm, the maximum efficiency occurs at finder (L) =20 cm

Fig. 5-5-4 Results of cold separation of 600 µm

From these results we notice that the efficiency of separation decreases when

the diameters of sawdust decreases.

And the efficiency increases when air flow rate increases.

Combustion condition.

Firstly, combustion is made by LPG then sawdust is added, then

separation process is made by cyclone separator.

The maximum temperature of flue gases in the cyclone occurs at radial

distance of 16 cm

And the minimum temperature is at radial distance of 27 cm.


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Fig. 5-5-5 distribution for combustion temperature


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CONCLUSION


53

Cyclone separator is a simple method for separation, its initial cost is

inexpensive, it is easy for maintenance and we can burn solid fuels inside it.

Conclusion from cold condition:

We found that the efficiency of separation increases when the diameter of

sawdust increases.

The efficiency of separation increases when the air flow increases.

The maximum efficiency of separation occurs when the length of vortex

finder is equal to 20 cm.

Future work

We are proud as we are members in this project, it is the first time to

burn biomass fuel inside the cyclone separator as cyclone separator

was used for cold separation only.

We advise the next team to do more experimental in hot condition

and use many types of biomass fuel.


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Appendix

Thermocouples transformer tables

Standard temperature for type-B Thermocouples


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References

"Cyclone"

1- http://en.wikipedia.org/wiki/Cyclone_furnace

"Cyclone separator"

2- Improving cyclone performance by proper selection of the exit pipe

Hesham ELBATSH 2012.

"Cyclone mechanism"

3- http://www.ske-india.com/cyclones.html

"Cyclone design optimization"

4- Analysis and Optimization of Cyclone Separators Geometry Using

RANS and LES Methodologies - Khairy Elsayed- Brussels, October

2011.

"Cyclone overview"

5- http://www.babcock.com/products/Pages/Cyclone-Furnaces.aspx.

"Collection efficiency"

6- Prediction of the effect of dimension, particle density, temperature, and

inlet velocity on cyclone collection efficiency. JOLIUS GIMBUN,

THOMAS S. Y. CHOONG, A. FAKHRUL-RAZI.

7- "Swirl Flows". A k GUPTA - D G LILLEY - N SYRED.

8- Gas Cyclones and Swirl Tubes Principles, Design and Operation

Second Edition.

"Cyclone design"

9- http://aerosol.ees.ufl.edu/cyclone/section01.html

10- THEORETICAL STUDY OF CYCLONE DESIGN, LINGJUAN

WANG May 2004.

http://en.wikipedia.org/wiki/Cyclone_furnace

http://www.ske-india.com/cyclones.html

http://www.babcock.com/products/Pages/Cyclone-Furnaces.aspx

http://aerosol.ees.ufl.edu/cyclone/section01.html

Experimental study of cyclone seperators as combustor 1

Engineering

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