1. MD. GOLAM KABIR
PRIMEASIA UNIVERSITY
Welcome

2. Topic
Spinning, Dyeing & Utilities

3. Viyellatex Spinning Ltd

4. SPINNING
 Viyellatex Spinning has a well developed quality
assurance lab equipped with modern sophisticated
machineries for raw material and finished material
testing. All the machineries are imported from USA ,
Switzerland ,Italy, Germany & India. Produce100%
export oriented a very high quality yarn.

5. At a glance Viyellatex Spinning Ltd.
Viyellatex Spinning Ltd is a sister concern of Viyellatex Group. It equipped with
all brand new state of the art European machines. It was established in the year
2004.
Position hold Mr. K. M. Rezaul Hasanat (David), Chairman & CEO
No. of Spindle 40320 spindle in Ring unit.
1280 spindle in Rotor unit.
Capacity700 Tons per month (Ring Spinning)
200 Tons per month (Rotor Spinning)
Project Cost More than 200 crore.
Project area 7.50 Acres
Total Manpower 1140 person (Management Staff -37, Non-Management
Staff-127 & Worker-980)

6. Department wise Present Manpower Status
Section MS NMS WORKER
Plant Head 1 0 0
Production & Planning 17 14 845
Human Resources 06 68 N/A
Plant Maintenance
(Maintenance)
2 6 85
Plant Maintenance (Utility) 3 11 50
Quality Management 2 18 N/A
Material Management 2 6 N/A
Sales & Distribution 2 4 N/A
Accounts & Finance 1 0 0
ISS 1 0 0
Total 37 127 980

7. Machine specification
Blow room : Blendomat , SPMF , CLP, MX-I , CLC-3,
SP-F
Preparatory : Carding , Breaker drawing , Unilap ,
Comber ,Finisher Drawing , Simplex
Ring Section : Ring Frame
Finishing section : Autoconer , Heat setting

8. Production types
 In Viyellatex Spinning we produce two different
types of yarn . They are –
1. Combed yarn.
2. Carded yarn .
We have required different machine for producing
the above two types of yarn and their processing is
also different . The process flow chart for combed
and Carded yarn are given in the next.

9. Combed yarn
 Combed yarn is most precious, finer and thiner than
the carded yarn. Because the Carded Yarn is
produced by following some less manufacturing
steps than the Combed Yarn.

10. Process flow chart of combed yarn
Input Processing
Machineries
Output
Raw Cotton Blow Room Lap
Lap Carding Carded Sliver
Carded Sliver Pre-Comb Drawing Pre-comb drawn sliver
Pre-comb drawn sliver Super Lap Former Mini Lap
Mini Lap Comber Combed Sliver
Combed Sliver Post Comb Drawing Post Comb Drawn Sliver
Post Comb Drawn Sliver Speed Frame/ Simplex Roving
Roving Ring Frame Yarn
Yarn Winding Yarn in large package

11. CLC-3 CL-PMX-I SPMF BLENDOMATE
UNILAP COMBER
RING SIMPLEX POST COMBED
DRAWING
SP-F CARDING PRE COMBED
DRAWING
HEAT
SETTING
AUTOCONE
PROCESS FLOW CHART FOR COMBED YARN

12. Carded Yarn
 Carded Yarn needs less steps to follow to make a
yarn than the Combed yarn. The main purpose of
Combed yarn manufacturing is to create a yarn
which is highly finer and highly qualified.
Here i will give you a chart from where you will be
able to know about How A Yarn is made by the
combed yarn manufacturing process”

13. Process flow chart of carded yarn
Input Processing
Machineries
Output
Raw Cotton Blow Room Lap
Lap Carding Carded Sliver
Carded Sliver Drawing-1 drawn sliver
Breaker Sliver Drawing-2 Finish draw sliver
Finisher Drawn Sliver Speed Frame/ Simplex Roving
Roving Ring Frame Yarn
Yarn Winding Yarn in large package

14. PROCESS FLOW CHART FOR KARDED YARN
CLC-3 CL-PMX-I SPMF BLENDOMATE
RING SIMPLEX
FINISHER
DRAWING
SP-F CARDING BREAKER
DRAWING
HEAT
SETTING
AUTOCONE
PROCESS FLOW CHART FOR CARDED YARN

15. Sl
NO
Name of wastage Generated from Standard
wastage
percentage
Types of
wastage
01 Blow room dropping (BW) Blow room machines 2%~3% Usable
02 Card Dropping (CD) Carding 3%~4% Usable
03 Flat Strips (FS) Carding 1%~2% Usable
04 Sliver Wastage Carding , drawing, comber 0.25% Usable
05 Noil Comber 15%~16% Usable
06 Roving wastage Simplex, Ring 0.25% Usable
07 Pnueumafil Ring 2.0%~2.5% Usable
08 Hard wastage Autocone, Ring 0.50% Saleable
09 Filter wastage All machine 0.75% Unusuable
10 Microdust Blow room machines 0.50% Unusable
Different wastage of Ring Unit

16. Information in Rotor Unit

18. ROTOR MACHINE
1,Drafting
2,Twisting
3,Winding the yarn on the
paper tube .

19. Quality Management
 Viyellatex Spinning has a well developed quality
assurance lab equipped with modern sophisticated
machineries for raw material and finished material
testing. All the machineries are imported from USA ,
Switzerland ,Italy, Germany & India.

20. Different Lab QC machine
No. Machine name Model No. Origin Number of
M/c
1 USTER HVI SPECTRUM Spectrum 1 USA 1
2 USTER AFIS PRO Pro USA 1
3 SLIVER & ROVING REEL SRR:001 USA 1
4 PORTABLE SCALE LBP:001 USA 1
5 ELECTRONIC YARN REEL YRL:001 Italy 1
6 USTER AUTO SORTER 4 Switzerland 1
7 ELECTRONIC TWIEST
TESTER
002 Italy 1
8 LEA STRENGTH TESTER MAG- Y 0251 India 1
9 USTER TESTER 4sx Switzerland 1
10 MOISTURE TESTER HMT:001 USA 1
11 TECHOMETER LSR:103 UK 1
12 TENSION METER DTMB:500 Germany 1

21. Picture of lab machine
1
43
2
7
65
9
8
1110 12

22. Quality control strategy
The quality department of Viyellatex spinning ensures standard quality of yarn as per buyer’s
requirement . We always try to maintain quality in every steps of yarn manufacturing process.
Besides, we implement the standard norms to achieve quality product. For this , we prepare a yarn
engineering plan according to fibre properties and types of yarn. Then we send this plan to the
top management. Then the top management purchase raw cotton through different cotton
supplier . When the raw cotton arrives to the factory premises from the various cotton growing
country , at first we take sample from every bale according to invoice lot. Then these samples are
conditioned at 20~22c temp for 72 and above hours. After that we test these samples and prepare
bale management according to fibre properties . During bale management we consider all fibre
properties . Then we prepare lay down plan. When the fibre goes in the process we fix up
process parameter according to the production plan given by production department. Analyze and
control yarn fault and take corrective action in process while deviation found in case of urgent and
critical situations. QAD discuss with the related department to reduce wastage.
We have certification in “FLO Fair Trade “ , “CMIA”, “Organic”, “Okeo-Tex” CCI (Cotton council
International ) . So, only Viyellatex Spinning can produce this kind of certified yarn.
In a word QA department always try to produce qualityful yarn to keep the reputation of Viyellatex
Spinning in the textile sector.

23. This is the end About Spinning

24. Villatex Dyeing Unite.

25. Dyeing
 Dyeing is the process of adding color to textile
products like fibers, yarns, and fabrics. Dyeing is
normally done in a special solution containing dyes
and particular chemical material. After dyeing, dye
molecules have uncut Chemical bond with fiber
molecules. The temperature and time controlling are
two key factors in dyeing. There are mainly two
classes of dye, natural and man-made.

26. Different types of dyeing
 Reactive dye
 Disperse dye
 Azoic dye
 Acid dye
 Basic dye
 Vat dye.

27. About Villatex dyeing pocess
 Viyellatex Dyeing is covered by the 22 dyeing
machines & 2 Turning machines and every machines
are German branded and we have 30 tons per day
dyeing capacity. 24 hours running our dyeing section
by the three shift 3 hundred workers are working in
our dyeing section. This is 100% export oriented knit
dyeing plant.

28. Lay out of dyeing floor

29. About the machine of Viyellatex
 Total number of machine: 22
 Sample machine: 7
 Bulk Machine : 15

30. Total Capacity
Machine no Capacity
Machine 1
Machine 2.
Machine 3.
Machine 4.
Machine 5.
Machine 6.
Machine 7.
Machine 8.
Machine 9.
Machine 10.
Machine 11
Machine 12.
Machine 13
Machine 14.
Machine 15
Machine 16
Machine 17
Machine 18
Machine 19
Machine 20
Machine 21
Machine 22.
Total Capacity
500
1000
1000
25
25
250
500
750
25
120
200
250
750
1120
840
30
560
1680
840
1120
60
60
11705

31. Production Per Day (100% loading)
 At a time loading capacity = 11705kg
 Production per day(100% loading)= (11705*2.5)kg
= 29262kg
(Approx 30 ton)

32. Production Per Day (80% loading)
 At a time loading capacity = 9364kg
Production per day(80% loading)= (9364*2.5)kg
= 23410kg
(Approx 25 ton)

33. Machine Specification
No. Name Type Model No. Origin Capacity No. of Nozzle
1 FONG’S Bulk 28015002 China 500kg 2
2 THIES Bulk 45505 Germany 1000kg 4
3 THIES Bulk D-48653 Germany 1000kg 4
4 FONG’S Sample 28015001 China 25kg 1
5 THIES Sample D-48653 Germany 25kg 1
6 THIES Bulk 41346 Germany 250kg 1
7 THIES Bulk 41350 Germany 500kg 2
8 THIES Bulk 41354 Germany 750kg 3
9 FONG’S Sample 30019009 China 25kg 1
10 FONG’S Sample 30019010 China 120kg 1
11 FONG’S Bulk ECO-6-IT China 200kg 1
12 FONG’S Bulk ECO-6-IT China 250kg 1
13 FONG’S Bulk 31021190 China 750kg 3
14 FONG’S Bulk 31021190 China 1120kg 4
15 FONG’S Bulk 31021189 China 840kg 3
16 FONG’S Sample 31021188 China 30kg 1
17 FONG’S Bulk 32022490 China 560kg 2
18 FONG’S Bulk 32022493 China 1680kg 6
19 FONG’S Bulk 32022491 China 840kg 3
20 FONG’S Bulk 32022492 China 1120kg 4
21 FONG’S Sample 32022489 China 60kg 1
22 FONG’S Sample 32022488 China 60kg 1

34. Process flow chart of Knit dyeing.
Batching/Grey Fabric Inspection
↓
Sewing or Stitching
↓
Scouring
↓
Bleaching
↓
Mercerizing
↓
Dyeing
↓
Printing
↓
Finishing
↓
Final Inspection
↓
Delivery

35. MACHINE DESCRIPTION
 There is two types of dyeing machine use in Viyellatex,
 Thise
 Fongs

36. Different production capacity of
machine.
Machine NO. Machine name Machine capacity Origin
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Fong’s
Thies.
Thies
Thies
Thies
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
Fong’s
500
1000
1000
500
750
120
200
250
750
1120
840
560
1680
840
1120
China
Germany
Germany
Germany
Germany
China
China
China
China
China
China
China
China
China
China

37. Different parts of dyeing machine..
Stairs
Unload reel
Unloader
Lid
Reel motor
Light
Reel
Nozzle
Dyeing chamber
Main pump
Chemical tank 1.
Chemical tank 2.
Water bulb
Steam tank
Drain line
Pressure bulb
Chemical tank filter
Chemical tank mixtuture.
Reel switch board.
Chemical tank switch
board.
Panel board.
Heat exchanger
Filter
Water line
Steam line

38. Thies machine.

39. Feature of Thies machine.
 Filter is at the inside of the machine.
 Need more time & water for machine wash.
 Chamber size is fixed not adjustable.
 Nozzle size is manually adjustable.
 The chamber is half round shaped.
 There is a heat chamber in vertically.
 Nozzle is situated at the top of the machine.
 There is a pressure bulb in the lid.
 The chemical are manually mixed with the help of stirrer.
 No need to clean the filter of the machine.
 Origin at Germany.

40. Fong’s machine.

41. Feature of Fong’s machine.
 Filter is at the inside of the heat exchanger of the machine.
 Need small time & water for machine wash with the help of spray
rod.
 Chamber size is adjustable.
 Nozzle size is automatically adjustable.
 The chamber is fully round shaped.
 There is a heat chamber in horizontally at the back side of the
machine .
 Nozzle is situated at the side of the machine.
 There is a pressure bulb in the lid if the machine is HTTP.
 The chemical are automatically mixed with the help of mixture.
 Filter need to clean.
 Origin at China.

42. The technique of dyeing.

43. Difference between Thies & Fong’s machine
No Thies Fong’s
1 Filter is at the inside of the machine. Filter is at the inside of the heat exchanger of the machine.
2 Need more time & water for machine wash. Need small time & water for machine wash with the help of
spray rod.
3 Chamber size is fixed not adjustable. Chamber size is adjustable.
4 Nozzle size is manually adjustable. Nozzle size is automatically adjustable.
5 The chamber is half round shaped. The chamber is fully round shaped.
6. There is a heat chamber in vertically. There is a heat chamber in horizontally.
7 Nozzle is situated at the top of the machine. Nozzle is situated at the side of the machine..
8 No need to clean the filter of the machine. Filter need to clean.
9 The chemical are manually mixed with the help of
stirrer.
The chemical are automatically mixed with the help of
mixture.
10 Origin at Germany. Origin at China

44. Calculation of Winch Speed
Let,
Fabric weight = 1000kg
Per nozzle fabric weight =250kg
Fabric Diameter (open) = 56 inch
Cycle time or Dwell time = 2.5-3.0 m per
minute G.S.M =180
We know, GSM = gram / meter2
= gram / (Length × Diameter)
Or, Length = gram / (GSM × Diameter)
= (250×1000× 100) /
(56×2.54× 180)
= 976 meters.
So, Winch or Reel Speed = Per nozzle Fabric length / Cycle time
= 976 / 3 meter/minute
= 325 meter/minute.
Calculation of Linear Density:
Linear Density = (Diameter×GSM×2.54) / 100 gram/meter

45. Dyeing process flow chart
Grey fabric receive from knitting section
↓
Batching
↓
Turning of fabric (only for Single Jersey)
↓
Selection machine no
↓
Fabric loading
↓
Select production program
↓
Select recipe for dyeing
↓
Pretreatment
↓
Dyeing
↓
After treatment
↓
Fabric Unload

46. Production Parameters
 PH
Scouring PH – 12.5
During H2O2 bleaching PH 10.5-11
Enzyme PH – 4.5
Before dyeing (Leveling) PH – 6.5
Salt PH – 7-8
During reactive dyeing PH 10.5-11.5
During disperse dyeing PH 4.5-6.0
Softener PH – 6.5
 Time:
For white fabric 4-5hrs
For 100% cotton 8-10hrs
For 100% polyester 5hrs
CVC 2 parts 13-14 hrs.

47. Production Parameters
 Temperature:
For cotton fabric scouring: 105ºC
During NaOH addition 65oC
During H2O2 addition 70oC
Peroxide killing at 80oC
Sequestering at 90oC
Bio-polishing at 55oC
For cotton dyeing:
Low brand – 45oC
Medium brand - 600C
Hot brand – 80oC
Migration for turquoise color at – 90oC
Optical brightening agent (OBA) at – 80oC
Polyester dying: 1000-1300C
Softener at – 45oC
 M: L ratio:
For reactive dyeing M: L ratio maintained between 1:6

48. Pretreatment process
 Typical recipe for scouring: (all in g/l)
 Felson NOF – 0.7
 Kapazon H53 – 0.5
 Caustic – 2
 H2O2 – 2.5
 Recorit wez/Peroxide killer – 0.75
 Acetic acid – 0.8
 Biopolish B-11 – 1.5
 Securon 540 – 0.5

49. Pretreatment flow chart
Fresh water and fabric Load at 45oC
Temperature raise to 60oC
Detergent, Peroxide Stabilizer inject
Run for 5 min
Inject Caustic and run 5 min
Raise temperature to 70oC
H2O2 inject and run 5 min
Temperature raise to 105oC
Run for 30 min
Lower the temperature to 80oC
Bath drain
Peroxide killer inject and run 10 min
Rinsing and unload the fabric.

50. Curve for scouring of fabric

51. Types of shade
 Light
 Medium
 Dark
 White

52. Curve for black shade (dark) cotton dyeing

53. Curve for Cotton part Dyeing

54. Curve for White shade

55. Curve for Polyester dyeing

56. Curve for dyeing with turquoise color

57. Common dyeing faults with their remedies
Uneven dyeing
 Causes:
Uneven pretreatment (uneven scouring & bleaching).
Rapid addition of Dyes and Chemicals.
Improper color dosing.
Using dyes of high fixation property.
Uneven heat-setting in case of synthetic fibers.
Lack of control on dyeing m/c
 Remedies:
By ensuring even pretreatment.
By ensuring even heat-setting in case of synthetic fibers.
Proper dosing of dyes and chemicals.
Proper controlling of dyeing m/c

58. Common dyeing faults with their remedies
Batch to Batch Shade variation
 Causes:
Fluctuation of temperature.
Improper dosing time of dyes & chemicals.
Batch to batch weight variation of dyes and chemicals.
Dyes lot variation.
Improper reel speed, pump speed, liquor ratio.
Improper pretreatment.
Liquor ratio changed.
Different dyeing procedure for each batch.
 Remedies:
Use standard dyes and chemicals.
Maintain the same liquor ratio.
Follow the standard pretreatment procedure.
Maintain the same dyeing cycle.
Identical dyeing procedure should be followed for the same depth of the Shade.
Make sure that the operators add the right bulk chemicals at the same time and temperature in the
process.
The pH, hardness and sodium carbonate content of supply water should check daily.

59. Common dyeing faults with their remedies
Dye Spots
 Causes:
Not proper agitation of dyestuffs.
Dye bath hardness.
Operators ignorance about mixing and dissolving the dyestuffs and
chemicals.
 Remedies:
Proper agitation of dyestuffs.
Use adequate amount of sequestering agent to minimize hardness.

60. Remarks
I have seen that in dyeing different production
parameters like temperature, time, PH, M:L ratio
etc. are strictly followed. Sometimes the original
dyeing process may not be found according to dyeing
curve as they produce some complicated shade. One
thing is clearly noticeable that production manager
and officers are committed to try their best for
reducing production time.

61. Viyellatex Utilities

62. Boiler
 Introduction:
A boiler is a closed vessel in which water under
pressure is transformed into steam by the application of heat. In
the boiler furnace, the chemical energy in the fuel is converted into
heat, and it is the function of the boiler to transfer this heat to the
contained water in the most efficient manner. The boiler should
also be designed to generate high quality steam for plant use. A
flow diagram for a typical boiler plant is presented in Figure.

63. Boiler Plant Flow Diagram

64. Fuel
The source of heat for a boiler is combustion of any of several
fuels, such as: wood,
A. Coal,
B, Oil,
C. Natural gas.
Electric steam boilers use resistance- or immersion-type
heating elements. Nuclear fission is also used as a heat source
for generating steam. Heat recovery steam generators
(HRSGs) use the heat rejected from other processes such as
gas turbines.

65. Classification of steam
boiler
1. According to the contents in the tube.
2. According to the position of the furnace.
3. According to the axis of the shell.
4. According to the number of tube.
5. According to the method of circulation of water &
steam.
6. According to the use.
7. According to the source of heat.

66. Pot boiler or Haycock boiler
 "Pot boiler" or "Haycock boiler": a primitive "kettle" where a fire
heats a partially-filled water container from below. 18th century
Haycock boilers generally produced and stored large volumes of
very low-pressure steam, often hardly above that of the
atmosphere. These could burn wood or most often, coal.
Efficiency was very low.

67. Fire-tube boiler
 Fire-tube boiler. Here, water partially fills a boiler barrel with a small volume left
above to accommodate the steam (steam space). This is the type of boiler used in
nearly all steam locomotives. The heat source is inside a furnace or firebox that has
to be kept permanently surrounded by the water in order to maintain the
temperature of the heating surface just below boiling point. The furnace can be
situated at one end of a fire-tube which lengthens the path of the hot gases, thus
augmenting the heating surface which can be further increased by making the gases
reverse direction through a second parallel tube or a bundle of multiple tubes (two-
pass or return flue boiler); alternatively the gases may be taken along the sides and
then beneath the boiler through flues (3-pass boiler). In the case of a locomotive-
type boiler, a boiler barrel extends from the firebox and the hot gases pass through
a bundle of fire tubes inside the barrel which greatly increase the heating surface
compared to a single tube and further improve heat transfer. Fire-tube boilers
usually have a comparatively low rate of steam production, but high steam storage
capacity. Fire-tube boilers mostly burn solid fuels, but are readily adaptable to
those of the liquid or gas variety.

68. Water-tube boiler
 Water-tube boiler. In this type, the water tubes are arranged inside
a furnace in a number of possible configurations: often the water
tubes connect large drums, the lower ones containing water and
the upper ones, steam and water; in other cases, such as a
monotone boiler, water is circulated by a pump through a
succession of coils. This type generally gives high steam
production rates, but less storage capacity than the above. Water
tube boilers can be designed to exploit any heat source and are
generally preferred in high pressure applications since the high
pressure water/steam is contained within small diameter pipes
which can withstand the pressure with a thinner wall.

69. Flash boiler
 A flash boiler is a type of water-tube boiler, whose tubes
are strong and close together with water pumped through
the tubes. The tubes are kept very hot so the water feed is
quickly flashed into steam and superheated. The flash
boiler was invented by Léon Serpollet, who used the
design in his steam-powered cars.
 Compared to other kinds of boilers, they have the
advantages of being lighter and less bulky and taking less
time to raise steam from a cold start. On the other hand, a
flash boiler is much easier than an ordinary boiler to
overheat, as there is no large reservoir of water to cool
the tubes in case the water flow is interrupted or
inadequate

70. Fire-tube boiler with Water-
tube firebox
 Fire-tube boiler with Water-tube firebox. Sometimes the two
above types have been combined in the following manner:
the firebox contains an assembly of water tubes, called
thermic siphons. The gases then pass through a conventional
firetube boiler. Water-tube fireboxes were installed in many
Hungarian locomotives, but have met with little success in
other countries.

71. Sectional boiler
 In a cast iron sectional boiler, sometimes called a "pork
chop boiler" the water is contained inside cast iron
sections. These sections are assembled on site to create
the finished boiler.

72. Steam Utilization
Steam is generated for the following plant uses:
1. Turbine drive for electric generating equipment,
blowers and pumps
2. Process for direct contact with products, direct
contact sterilization and noncontact for
processing temperatures
3. Heating and air conditioning for comfort and
equipment

73. Supercritical Steam
Generators
Supercritical steam generators (also known as Benson boilers)
are frequently used for the production of electric power. They operate
at "supercritical pressure". In contrast to a "subcritical boiler", a
supercritical steam generator operates at such a high pressure (over
3,200 psi/22.06 MPa or 220.6 bar) that actual boiling ceases to occur,
and the boiler has no water - steam separation. There is no generation
of steam bubbles within the water, because the pressure is above the
"critical pressure" at which steam bubbles can form. It passes below
the critical point as it does work in the high pressure turbine and
enters the generator's condenser. This is more efficient, resulting in
slightly less fuel use. The term "boiler" should not be used for a
supercritical pressure steam generator, as no "boiling" actually occurs
in this device.

74. boiler
 Boiler fittings and accessories
Safety valve: It is used to relieve pressure and prevent possible explosion of a boiler.
Water level indicators: They show the operator the level of fluid in the boiler, also
known as a sight glass, water gauge or water column is provided.
Bottom blowdown valves: They provide a means for removing solid particulates that
condense and lie on the bottom of a boiler. As the name implies, this valve is usually
located directly on the bottom of the boiler, and is occasionally opened to use the
pressure in the boiler to push these particulates out.
Continuous blowdown valve: This allows a small quantity of water to escape
continuously. Its purpose is to prevent the water in the boiler becoming saturated
with dissolved salts. Saturation would lead to foaming and cause water droplets to be
carried over with the steam - a condition known as priming. Blowdown is also often
used to monitor the chemistry of the boiler water.
Flash Tank: High pressure blowdown enters this vessel where the steam can 'flash'
safely and be used in a low-pressure system or be vented to atmosphere while the
ambient pressure blowdown flows to drain.

75. Different parts and function of boiler
Automatic Blowdown/Continuous Heat Recovery System: This system allows the boiler to blowdown
only when makeup water is flowing to the boiler, thereby transferring the maximum amount of heat possible
from the blowdown to the makeup water. No flash tank is generally needed as the blowdown discharged is
close to the temperature of the makeup water.
Hand holes: They are steel plates installed in openings in "header" to allow for inspections & installation of
tubes and inspection of internal surfaces.
Steam drum internals, A series of screen, scrubber & cans.
Low- water cutoff: It is a mechanical means (usually a float switch) that is used to turn off the burner or
shut off fuel to the boiler to prevent it from running once the water goes below a certain point. If a boiler is
"dry-fired" (burned without water in it) it can cause rupture or catastrophic failure.
Surface blowdown line: It provides a means for removing foam or other lightweight non-condensible
substances that tend to float on top of the water inside the boiler.
Circulating pump: It is designed to circulate water back to the boiler after it has expelled some of its heat.
Feedwater check valve or clack valve: A non-return stop valve in the feedwater line. This may be fitted to
the side of the boiler, just below the water level, or to the top of the boiler.
Top feed: A check valve (clack valve) in the feedwater line, mounted on top of the boiler. It is intended to
reduce the nuisance of limescale. It does not prevent limescale formation but causes the limescale to be
precipitated in a powdery form which is easily washed out of the boiler.
Desuperheater tubes or bundles: A series of tubes or bundles of tubes in the water drum or the steam drum
designed to cool superheated steam. Thus is to supply auxiliary equipment that does not need, or may be
damaged by, dry steam.
Chemical injection line: A connection to add chemicals for controlling feedwater pH.

76. Different parts and function
of boiler
 Steam accessories
• Main steam stop valve:
• Steam traps:
• Main steam stop/Check valve: It is used on
multiple boiler installations.

77. Different parts and function
of boiler
 Combustion accessories:
Fuel oil system
Gas system
Coal system
Soot blower

78. Different parts and
function of boiler
 Other essential items:
 Pressure gauges
 Feed pumps
 Fusible plug
 Inspectors test pressure gauge attachment
 Name plate
 Registration plate

79. Diagram of a boiler

81. Production of a boiler.
 Production/hr = 6 ton.
 .’. Production /day, 6 * 24 = 144 ton
 Viyella tex need 144 ton steam for regular
production.

82. Steam required different section
 Dyeing =
 Garments =
 Fabric =
 Printing =
 Fashion & plastic =
 Others =

83. Difference between water tube
& faire tube boiler.
NO Water tube boiler Fire tube boiler
1 The water circulates inside the tubes which
are surrounded by hot gases from the
finance.
The hot gases from the furnace pass
through the tubes which are surrounded by
water.
2 It generates steam at a higher pressure
upto165 bar.
It can generate steam only upto 24.5 bar.
3 The rate of generation of steam is high, i.e.
upto 450 tons per hour.
The rate of generation of steam is low, i.e.
upto 9 tons per hour.
4 Overall efficiency with economizer is upto
90%.
It overall efficiency is only 75%.
5 It is preferred for widely fluctuating loads. It can also cope reasonably with sudden
increase in load but for a shorter period.
6 The direction of water circulation is well
defined.
The water does not circulate in a definite
direction.
7 The operating cost is high. The operating cost is less.

84.  An air compressor is a m/c to compress the air & to
raise its pressure. The air compressor sucks air
from the atmosphere, compresses it & then delivers
the same under a high pressure to a storage vessel.
From a storage vessel, the pipeline to a place where
the supply, of compressed air is required.
AIR COMPRESSOR

85. Type of air compressor

86.  Reciprocating air compressors are positive displacement machines, meaning that they increase
the pressure of the air by reducing its volume. This means they are taking in successive volumes
of air which is confined within a closed space and elevating this air to a higher pressure. The
reciprocating air compressor accomplishes this by a piston within a cylinder as the compressing
and displacing element.
 Single-stage and two-stage reciprocating compressors are commercially available.
 Single-stage compressors are generally used for pressures in the range of 70 psig to 100 psig.
 Two-stage compressors are generally used for higher pressures in the range of 100 psig to 250
psig.
 Note that
 1 HP ~ 4 CFM at 100 psi
 and that 1 to 50 HP are typically for reciprocating units. Compressors 100 hp and above are
typically Rotary Screw or Centrifugal Compressors.
 The reciprocating air compressor is single acting when the compressing is accomplished using
only one side of the piston. A compressor using both sides of the piston is considered double
acting.
 Load reduction is achieved by unloading individual cylinders. Typically this is accomplished by
throttling the suction pressure to the cylinder or bypassing air either within or outside the
compressor. Capacity control is achieved by varying speed in engine-driven units through fuel
flow control.
 Reciprocating air compressors are available either as air-cooled or water-cooled in lubricated
and non-lubricated configurations and provide a wide range of pressure and capacity selections.
Reciprocating Air Compressors

88.  Rotary air compressors are positive displacement compressors. The most
common rotary air compressor is the single stage helical or spiral lobe oil flooded
screw air compressor. These compressors consist of two rotors within a casing
where the rotors compress the air internally. There are no valves. These units are
basically oil cooled (with air cooled or water cooled oil coolers) where the oil seals
the internal clearances.
 Since the cooling takes place right inside the compressor, the working parts never
experience extreme operating temperatures. The rotary compressor, therefore, is
a continuous duty, air cooled or water cooled compressor package.
 Rotary screw air compressors are easy to maintain and operate. Capacity control
for these compressors is accomplished by variable speed and variable compressor
displacement. For the latter control technique, a slide valve is positioned in the
casing. As the compressor capacity is reduced, the slide valve opens, bypassing a
portion of the compressed air back to the suction. Advantages of the rotary screw
compressor include smooth, pulse-free air output in a compact size with high
output volume over a long life.
 The oil free rotary screw air compressor utilizes specially designed air ends to
compress air without oil in the compression chamber yielding true oil free air. Oil
free rotary screw air compressors are available air cooled and water cooled and
provide the same flexibility as oil flooded rotaries when oil free air is required.
Rotary Screw Compressors

90.  The centrifugal air compressor is a dynamic compressor which
depends on transfer of energy from a rotating impeller to the air.
 Centrifugal compressors produce high-pressure discharge by
converting angular momentum imparted by the rotating impeller
(dynamic displacement). In order to do this efficiently, centrifugal
compressors rotate at higher speeds than the other types of
compressors. These types of compressors are also designed for
higher capacity because flow through the compressor is continuous.
 Adjusting the inlet guide vanes is the most common method to
control capacity of a centrifugal compressor. By closing the guide
vanes, volumetric flows and capacity are reduced.
 The centrifugal air compressor is an oil free compressor by design.
The oil lubricated running gear is separated from the air by shaft
seals and atmospheric vents.
Centrifugal Compressors

92.  There are three parts of an air compressor:-
 Main compressor
 Air heater.
 Air reserver.
Different parts of an air compressor.