Utilities used in textile industry

1.According to relative position of water and hot gases a Fire tube boilers; If the hot gases of combustion from the furnace pass through the tubes and water is surrounding the tubes is

UTILITIES USED IN TEXTILE

INDUSTRY

UNIVERSITY OF KARACHI CHEMICAL ENGINEERING

UTILITIES SECTIONUtilities section is the department which supply

UTILITY DEFINITION:

Utility provide services to industry

processes

UTILITIES SECTION:

 Electricity is used to run the machine in industry It is power source for machinery.

2.STEAM:

 Steam is the vaporized state of water which contains heat

energy and transfer that energy into a variety of processes in textile industry

 Boilers are the common installation in utility plants to

produce steam.

Applications in textile industry:

 In textile industry Steam is used for fiber production,

weaving , dyeing , drying , printing, heating the equipment and maintaining the temperature of system

A boiler is basically a closed vessel into which water is heated

until the water is converted into steam at required pressure.

Classification of Boilers:

Boilers can be classified as follows:

1. According to relative position of water and hot gases

2. According to geometric orientation of boiler

3. According to location of furnace

4. According to method of water circulation

5. According to working pressure

6. According to mobility of boiler

7. According to number of tubes in the boiler

1.According to relative position of water and hot gases

a) Fire tube boilers; If the hot gases of combustion from the furnace pass

through the tubes and water is surrounding the tubes is called fire tube boilers b) Water tube boiler; If the water passes through the tubes and hot gases

surrounding the tubes is called water tube boiler

Water Tube Boiler Fire Tube Boilers

2.According to geometric orientation of boiler

a Horizontal boiler; If the axis of boiler is horizontal is called Horizontal boiler

b Vertical boiler; If the axis of boiler is vertical then it is called vertical boiler

c Inclined boiler; If the axis of boiler is inclined then it is called inclined boiler.

3.According to location of furnace

d Externally fired boilers; In this boiler the furnace is placed outside the boiler shell Generally water tube boilers are externally fired

e Internally fired boilers; In this boiler the furnace is placed inside the boiler shell Generally fire tube boilers are internally fired

4.According to method of water circulation

f Natural circulation boilers; In this boiler, water flow take place naturally, by

density difference of water The flow of water and steam are set up due to density difference resulting from difference in temperature

g Forced circulation boilers; In this boiler, water flow takes place by a pump.

5.According to working pressure

a High pressure boiler; The working pressure of this boiler is higher than 25 bar

b Medium pressure boiler; The range of working pressure of this boiler is between 10 bar to 25 bar

c Low pressure boiler; The range of working pressure is between 3.5 to 10 bar

6.According to mobility of boiler

d Stationary boiler; This boiler cannot be moved easily from one place to another place This are used in power generation or

process heating in industries

e Mobile boiler; It is easily moved

7.According to numbers of tubes in the boiler

f Single tube boiler; This boiler having only one fire or water tube for circulation of hot gases or water

g Multi-tube boiler ; This boiler having two or more fire or water tubes for the circulation of hot gases or water

3.WATER :

The textile industry consumes large amount of water in its varied processing operations

In textile wet processing, water is used mainly for two purposes

Firstly, as a solvent for processing chemicals and

Secondly , as a washing and rinsing medium

The quantity of water required for textile processing varies from mill to mill depending on fabric produce, process, equipment type and dyestuff

The longer the processing sequences, the higher will be the quantity of

water required

Bulk of the water is utilized in washing at the end of process

In the mechanical processes of spinning and weaving, water consumed is very small as compared to textile wet processing operations, where water is used extensively

Water consumption in Textile industry

COOLING TOWER:

 A Cooling tower is a heat rejection device which

removes waste heat to the atmosphere through the

cooling of a water stream to a lower temperature

 Cooling towers use the evaporation of water toremove process heat and cool the working fluid

 Cooling towers remove excess heat from large structures; heat that is the product of machinery, processed material, and mechanical processes

 The main purpose of cooling towers is to cool the

circulating water used in these structures

Classification Of Cooling Tower

 On the basis of air flow:

1.Natural draft

No external mean required to force or draw air through the tower.

2.Mechanical draft

Uses power-driven fan motors

to force or draw air through the tower.

i Induced draft

ii Forced draft

.On the basis of air-to-water flow

1.Cross flow

2.Counter flow

Mechanical draft:

It is divided into two types:

i) In induced draft cooling towers, the fan is mounted at the top of the tower and is used to

"pull" air through the tower

ii) In forced draft cooling towers, the fan is mounted on the side of the tower and is used to

"push" air through the tower

On the basis of air-to-water flow

i) In cross flow cooling towers, the air enters the side of the tower and travels perpendicularly to the water stream

ii) In counter flow cooling towers, the air

enters at the bottom of the tower and travels up

in the opposite direction of the water stream

 The induced draft counter flow cooling tower is

probably the most common.

4.COMPRESSED AIR:

 Compressed air is a form of stored energy that is used to operate machinery, equipment, or processes

 Air compressor , used to produce compressed air.

Application In Textile Industry:

 Compressed air is used mainly as a motive force to actuate the process control valves and machines in a textile mill

 It is also used for loom jet weaving, spinning , texturizing

AIR COMPRESSOR

 A compressor is a machine that is used to increase the

pressure of a gas

Positive displacement

Reciprocating Centrifugal Axial

Dynamic

Rotary

Classification Of Air Compressor

1.Positive-displacement Compressor

 In the positive-displacement type, a given quantity of air is

trapped in a compression chamber and the volume it

occupies is mechanically reduced, causing a corresponding

rise in pressure prior to discharge.

a Reciprocating Compressor

 A piston, driven through a crankshaft and connecting rod by

an electric motor, reduces the volume in the cylinder occupied

by the air or gas , compressing it to a higher pressure

b Rotary compressor

 Rotary compressors have rotors in place of pistons and give

a continuous discharge

 The most common type of rotary compressor is screw-type

 Rotary screw compressor consists of two intermeshing rotors, screw-rotors mesh, trapping air, and reducing the volume of the air along the rotors to the air discharge point resulting in increased pressure

 A centrifugal air compressor has a

continuously flowing air stream

which has velocity energy, imparted

to it by an impeller

 Approximately one half of the

pressure energy is developed in the

impeller with the other half achieved

by converting the velocity energy to

pressure energy as the air speed is

reduced in a diffuser and volute

BOILER WATER TREATMENT

 The primary function of a boiler water treatment

program is to keep heat transfer surfaces free from scale and deposition.

 Boiler deposits are problematical, as they typically contain undesirable levels of metal oxides, mineral scale, sludge, or various combinations.

 Boiler water treatment is used to remove suspended solid , dissolved solid and dissolved gases.

 The steps that are used to purify water before it goes to boiler

are:

1. Filtration to remove suspended solid

2. Reverse osmosis to remove dissolved solid

3. Deaeration to remove dissolved gasses

1.Carbon filter

.A pressure vessel, filter bed of various sizes of gravel, sand, and anthracite coal is usually sufficient to reduce suspended

solids to acceptable levels

. It remove some particles that cloud the water, reduce nasty chlorine residue and can even help

to reduce odors, thus improving the general taste and clarity of water.

2.Reverse osmosis

 RO involves separating water from a

solution of dissolved solids by forcing the water through a semi-permeable

membrane.

Deaerators exploit the physical properties of temperature and pressure to drive off dissolved gases

to remove the dissolved corrosive gasses( Hydrogen

(H2S) ,Carbon dioxide (CO2), Oxygen (O2))properly

temperature but the pressure is also exerted to stop boiling

phenomenon.

Gasses vent off