Sbo 10

Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar

Project on:

Calculation of unutilised heat and heat utilisation of blower (SBO10) in pet 300 bpm line Prepared by: Kushagra Abhishek Haldia Institute of Technology

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PREFACE Summer training at Raninagar was a very wonderful learning experience. It enables me to know the functioning of industry, which we are used to study study in theory. All theory norms were applied here to have glimpse of practical situation. Carried out a project here was yet another new and different experience. In this report there is a detailed situation prevailing in technical unit of industry and their working is discussed in detail.

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Acknowledgement I would like to thank Mr. Joydeep Roy , Production Manager at HCCBPL Raninagar for giving me a very challenging and interesting project on “Calculation of unutilised heat and heat utilisation of blower (sbo10) in pet 300 bpm line” . His proper guidance and instruction throughout the project work keeps me energetic and enthusiastic. I would like to thank him again for giving me a wonderful opportunity to have a firsthand industry experience. I would also like to thank Mr. Arindam Nath Roy and Mr. Argha Sarkar , both production executive for their valuable assistance throughout the project As and when required. At last but not the least I would also like to thank Sujit Dhar and Amit Roy, operator at blower room for their knowledge sharing on machine related issues.

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S.no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Content Abstract Introduction What is PET Why PET Preforms PET blowing basics PET blowing process Blow molding operation Bottle manufacturing process How blowing is done Compressor R- back system Preforms and bottle classification Parameters of blowing Oven heating and lamp setup Heat loss calculation Benefits of waste heat recovery Methods and equipments for recovery of waste heat Conclusion References

Page no. 5 6 7 7 8 8 8 9 9 13 13 13 14 15 15 17 20 23 25 26

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Abstract Heat loss from any system is highly undesirable for any industry, as huge potential of energy is wasted continuously from the stack or chimney of boiler, oven or furnace. So every industry is searching a way to utilise this waste heat to meet other energy requirement. By reducing the waste heat loss and utilising them, industry can save their capital. Industries are trying their level best in recovering Waste heat. During one month training at HCCBPL Raninagar, I have calculated amount waste heat which is escaping out to atmosphere from blower of SBO 10 in PET 300 BPM line. These heat loss can be minimised by installing a waste heat recovery unit having various type of direct and indirect contact heat exchanger. These waste heats have sufficient amount of energy, which can be used for heating of water, drying bottles and also can be used in RGB line in bottle washing .

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Introduction Hindustan coca cola beverage private limited, Raninagar is a company owned bottling unit. In India there are total 24 HCCBPL plant situated throughout the nation.HCCBPL Raninagar plant was set up in the year 2002in siliguri, west Bengal. Plant initially has only one production line of 100 bpm (bottles per minute).With passage of years it set up consecutively two more lines of production RGB(returnable glass bottle ) line and pet (Ploy Ethylene Terepthalic )300 bpm line. HCCBPL

100 bpm

300 pet bpm RGB

Raninagar plant is producing different coke flavour such as Sprite, Thums up, coke, Fanta, Limca, kinley (all 600, 1250 and 2000ml) and except kinley 600 ml. FLAVOUR

600 ml (SPT, KO, TU, KIN,FANTA, LIMCA)

1250 ml

2000 ml

(Except kinley all flavour)

(except kinley all flavour)

With a capacity of producing 1.5 lac bottles per day, its main consumption supply is in most districts of Bihar, North Bengal, and North Eastern states like Sikkim and Assam. Bottles are made from performs which is a polymer of ethylene glycol (EG) and Terepthalic acid (PTA). Plant get the supply of performs from Sikkim, Kolkata, and up. Perform manufacturer Canpet Epitome petrochemical ltd. AMD Chemco

Location Kolkata Sikkim U.P. Kolkata

This plant has various unit such as quality and its accessories, quality checking and laboratory, production having 100bpm,300 BPM and RGB line. There is also effluent treatment plant (ETP) and water treatment plant (WTP) which have capacity of treating effluent and water at 100 liter per day. During one month training at HCCBPL Raninagar plant, carried out a project on calculation of unutilised heat from sbo10 blower in pet 300 bpm line. In this report there is a detailed content on blow moulding equipment, operation and various its aspects.

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WHA T I S PET

Polyethylene

terephthalate (sometimes

written

poly(ethylene

terephthalate)),

commonly

abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. The term polyethylene terephthalate is a source of confusion because this substance, PET, does not contain

polyethylene. Depending on its processing and thermal history, polyethylene terephthalate may exist both as an amorphous (transparent) and as a semi crystalline polymer. The semi crystalline material might appear transparent (particle size < 500 nm) or opaque and white (particle size up to a few microns) depending on its crystal structure and particle size. Its monomer (bis- βhydroxyterephthalate) can be synthesized by the esterification reaction between terepthalic acid and ethylene glycol with water as a byproduct, or by transestrification reaction between ethylene glycol and dimethyl terephthalate with methano l as a byproduct. The majority of the world's PET production is for synthetic fibers (in excess of 60%), with bottle production accounting for around 30% of global demand. In the context of textile applications, PET is referred to by its common name, "polyester," whereas the acronym "PET" is generally used in relation to packaging. Polyester makes up about 18% of world polymer production and is the third-most-produced polymer; polyethylene (PE) and polypropylene (PP) are first and second, respectively.PET consists of polymerized units of the monomer ethylene terephthalate, with repeating C 10H8O4 units. PET is commonly recycled, and has the number "1" as its

OH

recycling symbol.

+ OH

OOHC

COOH

heat acid

(EG) (PTA)

PET WHY PET? There are many reasons for using pet for manufacturing of preforms some of them are listed below 

Good barrier property for co2 and o2



Minimal sensory impact



Safety and easy to handle



High mechanical property when it is stretched biaxial



Light weight and clarity and 100% recyclable 7


Some PET properties are: The production process of the preforms results in an amorphous structure of the PET, which is characterized by transparency, hardness, and fragility, at low temperature and high deformability at moderate temperature (about 100 °C). In this condition the material presents a Density of 1,370 g/cm3, a Heat Capacity at constant pressure of 1000 J/(kg·K) and a Thermal Conductivity of 0.15 W/(m·K). These values can vary depending on the characteristic of the material’s production process; consequently this study had been conducted by using literature values that can be relevant as a qualitative reference for the industrial practice.

Preforms used as a raw material for blowing operation it is made up of PET. Some preform details are : 

100% pet



Reliance/aspet resin supplier



Central procurement of resin cocacola



Approved perform suppliers will convert resin into perform



Perform supplier /resin supplier follows coca cola standard

Performs requirement are:

preforms



Differences in dimension in neck causes co2 losses and torque problems



In HCCBPL 28 mm PCO(plastic closure only) 1810 for CSD(Carburetted soft drinks) and 30/25 mm 3 start for water for neck are being used

PET Blowing basics:

Stretch blowing occurs in four steps:  Preform heating  Mechanical stretching – axial(vertical)  Radial stretching using compressed air (horizontal) first pre blow at 5 to15 bar and then

blow at 32 to 40 bar  Air recovery about 20 to 30% @ 10 bar  Exhaust

Types of blow moulding process: 

Raw material (generally resin) blown to bottle in a single machine. Ex are jars,20/25 l water bulk container. This is done single stage moulding process.



Two stage (used by HCCBPL): raw materials are converted perform in one machine and then performs are blown to bottle in other machine. Examples are all pet product. 8


Pet blowing process

Perform heating

mechanical stretching (Axial and vertical)

radial stretching a) pre blow (7 bar) b) Blow (40 bar)

outlet

air recovery at 10 bar (20 to 30%)

Blow moulding operation: For blowing performs into bottles HCCBPL Raninagar plant is using Sidel blow moulding machine which is called as sbo10 for heating of performs and SBO universal for molding operation .These machines are very highly efficient and consume, 45% less power than traditional blowing machines. Bottle manufacturing process:

There are various steps involved in bottle m aking .preforms goes to different stages via different equipment. These are discussed below:

Hopper: Preforms are dumped in large hopper having capacity up to 500 kg.

Elevators Performs are elevated to a certain height through elevator. These elevators are inclined 60 to70° with hopper base level. Preforms are then allowed to fall down in unscramble roller.

Unscramble roller These are somewhat complicated machines having two cylindrical rollers rotating axially in counter direction .There is a gap of about 2 cm between the roller so that due to continuous vibration preforms align themselves between roller having neck tucked in gap. Preforms which don’t align in gap are allowed to move back to hopper via recycling pipe.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar In feed rail : After coming from roller, performs arranges themselves in feed rail which are inclined at certain angle and then enter in SBO 10 machine. Before entering in oven zone of SBO10 performs follows some path profile, which is depicted in adjacent figure

Infeed wheel: Preforms from infeed rail are moved to infeed wheel which rotates and hence preforms are made to travel in horizontal line . From here preforms are moved to spindle chain.

Spindle chain: Spindles are cylindrical rod and which rotates on its axis .

performs are fixed in the spindle head .As spindle chain moves preforms also moves parallel to oven

so that

performs get heated up and it is easy to blow heated perform as it is flexible than hard and dry preforms. In one chain there are 196 spindles. There is a cooling ramp having circulation of cold water. This is necessary as to keep neck of preform cool, because in blowing process there is no any need of altering neck of preforms as it is same for all types of bottle.

Spindle wheel: These wheel are just to the reverse the direction of performs. So that preform again passes through another set of oven. From distribution oven to another of oven i.e. penetration oven.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Oven In SBO 10 machine there are two set of oven which is located on opposite side of machine. It’s SBO 10 because there are total 10 number of oven. First five set of oven is called distribution oven and second five set is called penetration oven. Each oven contain 9 infrared lamps which are fitted in oven one above other. First lamps from bottom of each oven have power rated of 3000 watt while rest of the lamps are 2500 watt.

Temperature of oven is set manually considering weight of performs in spindle chain, external or atmospheric temperature etc. oven temperature is controlled or set through by keeping ON different numbers of lamp at a time and also setting different zone heating percentage. It’s quite common to keep the temperature of oven below the melting point of preform.

Infrared lamp These lamps have power rated 2500 watt and 3000 watt. These lamps are ceramic coated which gives more radiations intense luminous Technical Data : Volts 400 Colour Temp Watts 3000 and 2500 watt, Life 5000 hr. Lumen/Watt 4-6 Burning Position Horizontal Finish Clear/refl ect coat.

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Above figure clearly depicts preform movement in oven zone also hoe preforms are heated can be easily understand by above figure. There is continuous reflection of IR rays from metallic shining surface which heat up the preforms. Blower After getting heated, performs enter the blower machine and get fitted itself in mould of blower. In Raninagar plant SBO blower in 300 pet line have 10 mould .rotates at a rate of 300 bpm. Mold Generally performs are fitted in mould and are given preblow pressure and then final blow pressure. There is continuous circulation of chilled water to keep the different parts like neck and base panel cool during blow so that bottles can’t burst. In HCCBPL there are different mould for 600 ml, 1250 ml and 2000 ml of bottle. Preforms get the shape in mould as final blowing pressure is applied.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar How blowing is done?

For blowing preforms into bottle there is application of 7bar to 10 bar pressure in heated preforms. This initial blowing process is called preblow. This is done to make performs more flexible so that it can bear later high blow pressure of 40 bar. If directly 40 bar pressure is applied in the preforms then bottle will burst frequently. For generating such high pressure of 40 bar plant have installed a 40 bar Ateliers Francois air compressor manufactured by Siemens, Belgium

Compressor These compressor generate 40 bar pressure in three stage at first stage 3.5 to 5 bar pressure is generated then 7 to 10 bar pressure is generated and finally 40 bar pressure at third stage is achieved.

rd

3.5 kg/cm2 1st stage

3

stage T=30-40°c

40 bar air

40 bar

40 Compressor

air tank

T=3-4°C Air dryer

2nd stage(10 bar)

Return back Air recovery tank

System

Air recovery

Main blow pressure 40 bar

Air tank

3.5 kg/cm2

Regulator Pre blow 15 bar Exhaust silencer

Mould

Before (To atmosphere, air not recovered)

7 bar Atomizer (for base spray)

For bottle rejection

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Raninagar plant is currently using kaizen formula of air recovery system in 40 bar air compressor. When bottle is blown then there is exhaust air coming out of mould having pressure up to 2

3.5kg/cm . Plant is collecting these pressurised air in air receiver tank .this enables compressor to move directly to second stage as first stage of attaining 3.5 bar pressure is already happened by air recovery system. By this company is claiming that they are saving rs.1875 per day at the same time reducing 2.5 tonnes of co 2 emission annually

After blowing of bottle it is ejected from blower having high temperature of about 80 to 100°c so water is sprayed in the base of bottle and then allowed to enter in the air conveyer which have air blower at fixed distance over it which blows dry air at very high velocity and pushes the bottles forward. Through air conveyer bottles are sent to filler section for filling up of beverages into the bottle. From there bottles are conveyed to labeller for labelling purpose through belt conveyer.

Coca cola Raninagar plan classifies preforms according to their weight and so that they can be molded and blowed in 600ml, 1.25lt and 2 lt bottle. Weight of preform volume flavour 27gm 600 ml Spt,kin,tu,ko,limca 25gm 39gm

600ml 1250 ml

fanta Spt,kin,tu,ko,limca

48 gm

2000ml

Spt,kin,tu,ko,limca

Bottles are classified as dimple, contour and splash.

Bottles

dimple

coke

generic

splash

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Different parameters and operating temperature and pressure for various flavour of coke bottle are given below: Perform weight

Flavour

27 gm 27 gm 27gm 27gm 39gm 39gm 48gm 48gm

Dimple/sprite Kin /TU Coke Fanta /limca Coke generic coke generic

Temperat ure of oven 106°c 120°c 120°c 120°c 210°c 205°c 210°c 220°c

Feeding temperatur e 85°c 85°c 85°c 85°c 135°c 140°c 160°c 190°c

Output %

Output setpoint

80 85 80 80 90 80 85 95

20000b/h 20000b/h 20000b/h 20000b/h 18000b/h 18000b/h 14000b/h 14000b/h

Preform temperatur e 99°c 99°c 98°c 99°c 93°c 96°c 95°c 110°c

Oven heating and lamp setup for preform heating is also given below: For 600 ml dimple Penetration oven Zone no.

1

2

3

4

Distribution oven** 5

6

7

8

9

10

9 8 7 6 5 4 3 2 1

For 600 ml coke

Lamp setup Penetration oven Zone no. 9

1

2

3

4


6

7

8

9

10

8 7 6 5 4 3 2 1

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar For 600 ml splash Lamp

setup

Penetration oven Zone no. 9

1

2

3

4


6

7

8

9

10

8 7 6 5 4 3 2 1

For 1250 ml generic clear Lamp setup Penetration oven Zone no.

1

2

3

4


6

7

8

9

10

9 8 7 6 5 4 3

.

2 1 For 1250 ml coke Lamp setup Penetration oven Zone no.

1

2

3

4


6

7

8

9

10

9 8 7 6 5 4 3 2 1

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar PET blow molding machines are the most popular technology employed to produce bottles and flagons. The process starts with the production of the PET, which is then used to make preforms that will be finally transformed into bottles. This paper will focus on the heating process of the preforms that leads to the final blow-molding transformation. The heating process is controlled through a series of panels, mounting Infra Red lamps, and the cooling airflow generated by dedicated fans. In fact one of the main issues in this transformation process is the temperature distribution along the preform length and the radial thickness, which should ideally vary according to the shape of the preform and the mechanical stresses introduced by the stretching action. Consequently the main objective of this development was to design an oven which gave the possibility of a fine regulation of the temperature in the PET section with a particular attention for the critical regions. The deep level of knowledge reached with this simulation work will lead to the production of better quality bottles, thanks to a higher level of reliability of the process, whilst also savings on production waste. Heat generated by oven is calculated by taking account no. of lamps ON and its overall zone heating percentage individually for each zone and then the heat coming from each zone is summed to get the total heating of oven. Also the heat acquired by preforms is calculated by very famous equation Q = mcpdT where Q is heat gained by one preform, m is mass of preform, c p is specific heat capacity of preform (c p for pet preform is 1KJ/Kg°c) dT is change in temperature of performs i.e. Preform temperature after coming from all set of ovens- perform external or normal temperature. Then for getting heat gained by performs in one hour, Q value is multiplied by no. of preform passing through oven in hour. Heat loss from blower is calculated by taking out the difference between total heat generated by oven and total heat gained by preforms in one hour.

(i)For 600 ml sprite bottle, heat loss calculation is done as follows:

Total heat given by all oven = sum of heat given by each zone For zone 1 i.e. for 3000 watt lamp, heat given= power X (no. of lamps ON) X overall heating % = 3000 X 8 X 0.64

considering 8 no. of on lamps 64% of overall heating of zone 1

= 15360 J/S For zone 2 to 9 i.e. for 2500 watt lamp, heat given = power X (no. of l amps ON) X overall heating % = 2500 X (6X.45+4X.29+4X.296+3X.53+6X.36) = 20192 J/S Total Heat given by oven = (15360+20192) J/S =127987.2 KJ/hr

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Heat gained by preform in one hour = m X c p X dT X (input rate of preform) =0.027 X 1X (99-25) X 16000 Cp of preform is 1kj/kg°c = 31968 KJ/hr and dT= (preform temperature – external temperature)

Heat loss or unutilised heat = total heat given by oven – heat gained by preform in one hour = (127987.2 – 31968) KJ/hr =96019.2 KJ/hr NOW heat required to raise the temperature of 100 litre of water from 20 to 50°c is computed as: Q=mcpdT, cp for water is 4.2 kj/kg°c = 100 X 4.2 X (50-20) KJ =12600 KJ only So we can utilise the waste heat coming out as exhaust to warm the water and use it in various other processing unit in the plant.

(ii)For 1250 ml sprite bottle, heat loss calculation is done as follows:

Total heat given by all oven = sum of heat given by each zone For zone 1 i.e. for 3000 watt lamp, heat given= power X (no. of lamps ON) X overall heating % = 3000 X 6 X 0.436

considering 6 no. of on lamps 43% of overall heating of zone 1

= 7848 J/S For zone 2 to 9 i.e. for 2500 watt lamp, heat given = power X (no. of lamps ON) X overall heating % = 2500 X(7X.523+3X.243+4X.337+3X.268+4X1.09) = 27305 J/S Total Heat given by oven = (7848 + 27305) J/S =126550 KJ/hr Heat gained by preform in one hour = m X c p X dT X (input rate of preform) =0.039 X 1X (105-25) X 14000 Cp of preform is 1kj/kg°c = 43680 KJ/hr and dT= (preform temperature – external temperature)

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Heat loss or unutilised heat = total heat given by oven – heat gained by preform in one hour = (126550 – 43680) KJ/hr =82870 KJ/hr (iii)For 2000 ml sprite bottle, heat loss calculation is done as follows:

Total heat given by all oven = sum of heat given by each zone For zone 1 i.e. for 3000 watt lamp, heat given= power X (no. of lamps ON) X overall heating % = 3000 X 6 X 0..436 considering 6 no. of on lamps 43% of overall heating of zone 1

= 28252KJ/S For zone 2 to 9 i.e. for 2500 watt lamp, heat given = power X (no. of lamps ON) X overall heating % = 2500 X (6X.44+3X.24+5X.40+3X.26+4X.1.07) = 94968 J/S Total Heat given by oven = (15360+20192) J/S =123220.2 KJ/hr Heat gained by preform in one hour = m X c p X dT X (input rate of preform) =0.047 X 1X (110-25) X12000 Cp of preform is 1kj/kg°c = 47940 KJ/hr and dT= (preform temperature – external temperature)

Heat loss or unutilised heat = total heat given by oven – heat gained by preform in one hour = (123220 – 47940) KJ/hr =27300 KJ/hr From above three heat loss calculation, we find that heat loss is not always constant it varies with the type of bottle in the production line. Also heat loss is more in case of small size bottle where as heat loss decreases when larger volume of bottles are made. Also heat emission is not continuous from oven because when there is any blockage in infeed rail or when preforms don’t undergo heating process then lamps get switched off thus saving power and cost. Also there is limited no. of lamps are kept ON so that optimum heating is achieved at low power. Sufficient Metallic reflector is placed in spindle line and also on both side of preform incoming line during its motion in oven zone to minimise the heat loss. Inspite of highly efficient designing of blower machine there is always some heat loss in the form of waste heat. Quality and quantity of such waste heat loss have been studied minutely and their further uti lisation in other process have been investigated.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Heat Losses –Quality Depending upon the type of process, waste heat can be rejected at virtually

any temperature from that of chilled cooling water to high temperature waste gases from an industrial furnace or kiln. Usually higher the temperature, higher the quality and more cost effective is the heat recovery. In any study of waste heat recovery, it is absolutely necessary that there should be some use for the recovered heat. Typical examples of use would be preheating of combustion air, space heating, or pre-heating boiler feed water or process water. With high temperature heat recovery, a cascade system of waste heat recovery may be practiced to ensure that the maximum amount of heat is recovered at the highest potential. An example of this technique of waste heat recovery would be where the high temperature stage was used for air pre-heating and the low temperature stage used for process feed water heating or steam raising. Heat Losses – Quantity In any heat recovery situation it is essential to know the amount of heat

recoverable and also how it can be used. An example of the availability of waste heat is given below: • Heat recovery from heat treatment furnace In a heat treatment furnace, the exhaust gases are leaving the furnace at 900oC at the rate of 2100 m3/hour. The total heat recoverable at 180oC final exhaust can be calculated as Q = V x ρ x Cp x ∆T Q is the heat content in kCal V is the flow rate of the substance in m3/hr Bureau of Energy Efficiency 1 8. Waste Heat Recovery ρ is density of the flue gas in kg/m3 Cp is the specific heat of the substance in kCal/kg oC ∆T is the temperature difference in oC Cp (Specific heat of flue gas) = 0.24 kCal/kg/oC Heat available (Q) = 2100 x 1.19 x 0.24 x (900-180) = 4,31,827 kCal/hr By installing a recuperator, this heat can be recovered to pre-heat the combustion air. The fuel savings would be 33% (@ 1% fuel reduction for every 22°C reduction in temperature of flue gas. Benefits of Waste Heat Recovery

Benefits of ‘waste heat recovery’ can be broadly classified in two categories: Direct Benefits:

Recovery of waste heat has a direct effect on the efficiency of the process. This is reflected by reduction in the utility consumption & costs, and process cost. Indirect Benefits :

a) Reduction in pollution: A number of toxic combustible wastes such as carbon monoxide gas, sour gas, carbon black off gases, oil sludge, Acrylonitrile and other plastic chemicals etc, releasing to atmosphere if/when burnt in the incinerators serves dual purpose i.e. recovers heat and reduces the environmental pollution levels.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar b) Reduction in equipment sizes: Waste heat recovery reduces the fuel consumption, which leads to reduction in the flue gas produced. This results in reduction in equipment sizes of all flue gas handling equipments such as fans, stacks, ducts, burners, etc. c) Reduction in auxiliary energy consumption: Reduction in equipment sizes gives additional benefits in the form of reduction in auxiliary energy consumption like electricity for fans, pumps etc. comparative study of waste heat in cocacola with other large industry such as steel or coal industry.

Coca cola

Heat is needed for blowing preforms purpose mainly , drying, warming water etc. All above process requires moderate amount of heat Maximum temperature of heat requirement is up to 160°C , because 220°C is the melting point of preforms and in cocacola all blowing operation is performed below the melting point.

other industry (steel, coal, cement etc.)

Heat is needed for melting solid, boiling etc. Above process requires very large quantity of heat at every processing stage. No any fixed maximum limit of temperature of heat requirement it may be around 2000°C t0 2500°C

Temperature of exhaust gas is about 1500°C Temperature of exhaust is about 120°C on an average. Quality of waste heat is of low grade as it have low temperature if collected may be used for space heating or air preheats. Most of the heat is lost in transportation of waste heat hence reducing its potential and usefulness

Exhaust gases or flue gas have sufficient heat capacity to be used in other process easily and efficiently high grade of exhaust gas is available Exhaust gas have large potential to be reused in boilers or furnace by recirculating it . Minimum heat is lost during transportation

Blower machine running in coca cola is very heat efficient there is only little loss of heat as compared to other processing industries. Temperature of exhaust gas in metallurgical industries is some times as high as 1500°C and quantity of exhaust gas is 10 times more than plastic related industry. In coca cola plant exhaust heat has temperature of about 120°C to 140°C only during peak running condition. The heat coming from is in the form of infrared radiation while other industries have flue gas which is produced by burning fuels or during combustion process.

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Stack of blower machine through which hot radiation and air escape to atmosphere. Temperature at stack inlet is about 120 °c and at stack outlet is about 50°c. to recover the waste heat which are escaping through stack , it is necessary to determine the area these waste if collected can find some use. (i)

It has been found that there is requirement of warm water of about 35c for spraying on bottles to carry out condensation on bottle surface because bottles which are coming out of filler is very cool and surface of bottle is chilled .

(ii)

Before labelling of bottle starts it is necessary to dry the surface of bottle so that labelling is done effectively, so there in labelling section there is provision of spraying hot air which has temperature of about 50c if waste heat is collected then it can be used to generate hot air by intermixing atmospheric air with exhaust gas.

(iii)

Space heating can also be achieved by this waste heat.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Methods and equipment for recovering waste heat These waste heat can be recovered by using heat exchanger, heat pipe , shell and tube , recuperator, heat wheel etc.

Heat pipe:

A heat pipe can transfer up to 100 times more thermal energy than copper, the best known conductor. In other words, heat pipe is a thermal energy absorbing and transferring system and have no moving parts and hence require minimum maintenance.

The Heat Pipe comprises of three elements – a sealed container, a capillary wick structure and a working fluid. The capillary wick structure is integrally fabricated into the interior surface of the container tube and sealed under vacuum. Thermal energy applied to the external surface of the heat pipe is in equilibrium with its own vapour as the container tube is sealed under vacuum. Thermal energy applied to the external surface of the heat pipe causes the working fluid near the surface to evaporate instantaneously. Vapour thus formed absorbs the latent heat of vapourisation and this part of the heat pipe becomes an evaporator region. The vapour then travels to the other end the pipe where the thermal energy is removed causing the vapour to condense into liqui d again, thereby giving up the latent heat of the condensation. This part of the heat pipe works as the condenser region. The condensed liquid then f lows back to the evaporated region.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Shell and tube heat exchanger:

When the medium containing waste heat is a liquid or a vapor which heats another liquid, then the shell and tube heat exchanger must be used since both paths must be sealed to contain the pressures of their respective fluid. The shell contains the tube bundle, and usually internal baffles, to direct the fluid in the shell over the tubes in multiple passes. The shell is inherently weaker than the tube, so that the higher-pressure fluid is circulated in the tubes while the lower pressure fluid flows through the shell. When a vapor contains the waste heat, it usually condenses, giving up its latent heat to the liquid being heated. In this application, the vapor is almost invariably contained within the shell. If the reverse is attempted, the condensation of vapors within small diameter parallel tubes causes flow instabilities. Tube and shell heat exchangers are available in a wide range of standard sizes with many combinations of materials for the tubes and shells.

Convective recuperator

A common configuration for recuperators is called the tube type or convective recuperator. As seen in the figure above, the hot gases are carried through a number of parallel small diameter tubes, while the incoming air to be heated enters a shell surrounding the tubes and passes over the hot tubes one or more times in the direction normal to their axes. If the tubes are baffled to allow the gas to pass over them twice, the heat exchanger is termed a two-pass recuperator; if two baffles are used, a three-pass recuperator, etc. Although baffling increases both the cost of the exchanger and the pressure drop in the combustion air path, it increases the effectiveness of heat exchange. Shell and tube type recuperators are generally more compact and have a higher effectiveness than radiation recuperators, because of the larger heat transfer area made possible through the use of multiple tubes and multiple passes of the gases.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Heat wheel

A heat wheel is finding increasing applications in low to medium temperature waste heat recovery systems. It is a sizable porous disk, fabricated with material having a fairly high heat capacity, which rotates between two side-by-side ducts: one is a cold gas duct, the other a hot gas duct. The axis of the disk is located parallel and on the partition between the two ducts. As the disk slowly rotates, sensible heat (moisture that contains latent heat) is transferred to the disk by the hot air and, as the disk rotates, from the disk to the cold air. The overall efficiency of sensible heat transfer for this kind of regenerator can be as high as 85 per cent. A variation of the heat wheel is the rotary regenerator where the matrix is in a cylinder rotating across the waste gas and air streams. The heat or energy recovery wheel is a rotary gas heat regenerator, which can transfer heat from exhaust to incoming gases. Its main area of application is where heat is exchanged between large masses of air having small temperature differences. Heating and ventilation systems and recovery of heat from dryer exhaust air are typical applications.

Waste heat recovery from blower will enable sharp reduction of power consumption along with limiting the emission of harmful gas into the atmosphere thus reducing global warming.

Conclusion: Utilisation of waste heat from stack is very much cost effective and can boost the power requirement of company to a large scale. So heat utilisation of exhaust from blower can be used to meet the energy requirement of the industry. Plant should work on heat utilisation, as maximum portion of energy input is wasted. Only small portion of heat input is converted into useful work and rest are allowed to escape into atmosphere which ultimately results in increase in pollution level. During one month training at coca cola plant, heat loss calculation is carried out and found that these waste heats have large potential of heating water, space heating and can be useful at many other processing units. Some methods of heat recovery have been also suggested, herewith.

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Hindustan Coca -Cola Beverages Pvt. Ltd., Raninagar Refrences: (i) (ii) (iii) (iv) (v) (vi)

Sidel training manual on blow molding machine Thermal Energy Equipment: Waste Heat Recovery by A.k. ghosh Best Practices and Industry Standards in PET Plastic Recycling by David J. Hurd, Associate Director BRONX 2000 ASSOCIATES, INC Sidel.com/blowing colution.pdf Principles of Heat Transfer Supplement to Heat Transfer Product Reviews March 2008 Version 1.1 Wikipedia.com/polyethylene terepthalate

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Sbo 10

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