CONTENTS

1. Acknowledgment2. Introduction3.Technical Collabration4.Main Objective of plant5. Basic design of plant6. Various section of plant7. Polymer process8. Process flow activities9. PSF spinning10. Fibre line flow chart11. Fibre line or draw line12. Recycle plant13. Utility plant14. Division of plant15.Electrical section16.Field Instruments17.PLC

ACKNOWLEDGEMENT

If the theoretical knowledge carves and shapes the career of a person, practical knowledgepolishes it and adds luster and brilliance to it. The six month training taken at IPCL was a learning experience for me. I am thankful to this organization for energizing my faith towards dignity of work.With great thanks to Mr. Sudhir Sharma (H.O.D, EE). I feel greatly honored toexpress my deep sense of gratitude to Mr. DIPANKAR GANGOPADHYA (MD, AFL) for giving me this opportunity. I am deeply indebted to Mr.AVTAR SINGH (AGM), Mr.B.B SHARMA(Manager, P&A), Mr. H.K. SONI (DGM & Head E&I),Mr. SALIL SHAH (Manager, INST.), Mr. LOKESH SHARMA (As-Manager), Mr. KULWANTSINGH (Deputy Manager, FIBRE LINE), Mr.HARISH PAL for helping me throughout this sixmonths training programme.I would also like to thank Mr.BALVINDER SINGH, Mr. SATPAL and othertechnicians for offering their sincere co-operation and sparing time for my queries. With theirselfless efforts and co-operation, I have been able to complete this training successfully.On the whole I am thankful to all of employees of IPCL, who directly or indirectlyhelped me in this v enture. I am also thankful to my friends for their assistance and co-operation who were with me at IPCL during this venture. ATUL KUMAR GUPTA351/03ELECT. ENGG.Univ. r no: - L-42605005DAVIET, JALANDHAR.

INDIAN PETROCHEMICAL CORPORATION LIMITED HOSHIARPUR COMPLEX FORMERLY KNOWN AS (APPOLLO FIBRES LIMITED)

INTRODUCTION

LOCATION : - In the outskirts of Hoshiarpur at Chohal, foothills of Shivalik on Dharamshala road.

YEAR OF ESTABLISHMENT : - 1988

TECHNICAL COLLABRATION : - World renowned M/S ZIMMER AG Of GERMANY

COMMERCIAL PRODUCTION : - Started in April 1989

PRODUCTS MANUFACTURED : - Polyester staple fiber (PSF) Partially oriented yarn (POY) Polyester chips

BRAND NAME : - RECRON

END USE OF PRODUCT : - Suiting, shirting, sewing thread, Sarees, Curtains etc.

TECHNICAL COLLABRATION

AFL has technical collaboration with germany and china. A German based company known as Zimmer AG installed it in 1988. Most of the instruments installed in the plant are redundant. The common example of redundant system is of HTM (Heat Transfer Medium) heaters ,DCS-Redundant controllers. To correct bursting out of pressure safety valve are mounted at various location. Beside these safety valves, there are various pressure transmitters mounted on various places through a microprocessor-based controller.

The company follows various protection standards needed for the protection of instruments for instance

IP -> Flame Proof IP ->Weather Proof & Flame proof

The Instrument used in the company’s are from much different company’s for e.g.

1. DCS PANEL -> ABB

2. PLC’S -> SIEMENS

3. CONTROLE VALVES -> ECKARDT

4. DIESEL GENERATORS->SKODA & MAN

5. LEVEL INDICATORS->MICROMOTION&ROSE

MOUNT

6. DRIVES (A.C & D.C)->SIEMENS

MAIN OBJECTIVE OF PLANT

Environment policy

At INDIAN PETROCHEMICALES CORPORATION Ltd (IPCL), protection of environmental is of prime concern and an important business objective. IPCL is conscious of its responsibilities towards creating, maintaining and ensuring a safe and clean environment for sustainable development.

The organization is committed to:

1) Comply with legal and other requirements ,which relate to its environmental aspects meeting the requirements of ISO 14000-Environment 5’s certification.

2) Plants trees ;develop green belt and lust green surrounding at our manufacturing location to work in harmony with nature.

3) make this policy available to the public.

Quality Policy

IPCL is committed to achieve and sustain a consistently high quality of their products and services to the entire satisfaction of their customers .The company is further committed to achieve and retain market leadership by producing and supplying a wide range of polyster staple fibers polstyer fiber fill ,poy and polyster chips meeting international standards at competitive prices.

The commitment is met by:

1) Adoptoin and Implementation of quality management system meeting the requirements of ISO 9001:2000.

2) Planning and efficient utilization of resources to control cost and minimize waste.

3) Utilizing the feedback from the customers for continuous improvement.

GENERAL BASIC DESIGN OF PLANT

The plant design is as follow:

Annual Capacity 92,000 TPA

Daily Capacity 270 TP day

Running Maximum Capacity 280 TP day

No of Esterification Reactor 2

No of Final reactor 2

Delustring Agent Titanium dioxide

No of Pre poly condensation reactor 3

Catalyst Antimony Trioxide

Vapour Heating Medium Dowtherm

Raw material PTA

Luster Semi dull, full dull

Finished Product POY, PSF, Polyester Chips

INDIAN PETROCHEMICALS LIMITED is one of the leading manufacturer of polyesterfibre in India and an associated company of Reliance Industries Ltd Mumbai(Mukesh AmbaniGroup).This plant has been producing Polyester fibre, POY ,Polyester fibre fill @1,10000 TPA andhaving approximately 1000 employees in plant operation and commercial department.Manufacturing process of polyester fibre at IPCL includes the following process steps:

I Polymerization Area

2 Spinning and Draw line of Polyester fibre 3Spinning of Drawline of polyester fibre fill plants 4 Spinning and draw line of POY

Detail of the above processes is as below

Polymerization Area:

This process involves the esterification and poly condensation reaction in between Mono Ethylene glycol and pure terpthallic acid by using antimony trioxide as catalyst and titanium dioxide as delusterant .

Spinning &draw line of Polyester staple fibre:

This process involves spinning of the polyester melt by passing through spinnerate having 600-1200holes and converting polyester melt into yarn by quenching the filament these filament are called tow and it has a moisture content of22% and is passed through dip bath having spin finish oil and then stretched at two stage drawing followed by thermo setting and crimping then the above tow converted into fibre tow which than passed through dryer at 160-180 Centigrade and than cut into different staple length at cutter .The staples of polyester fibre are then packed into the form of bales of 300kg and being sold to spinning and textile mills for making Polyester fabric.Spinning &draw line of polyester fibre fillSame procedure as above except using polyester flakes instead of polyester melt.Spinning and drawling of partially oriented filament yarn:In this process melted polyester is passed through spinnerate and being drawn into polyester filament yarn by providing quenching air. This filament yarn finally is winded on high speed winders and winded in the form of bobbins .These bobbins are being sold to fabric manufacturing textile mill

I NDIAN P ETROCHEMICAL C ORPORATION L IMITED HOSHIARPUR COMPLEX FORMERLY KNOWN AS (APPOLLO FIBRES LIMITED) VARIOUS SECTION OF PLANT( AN OVERVIEW)

POLY: -In this section the raw material PTA, glycol, catalyst, Titanium dioxide ismixed via chemical reaction and through various processes. The paste is formedand is known as melt. This paste is then stored in two disc ring reactor (DRR-l &DRR-2). From DRR-l the melt comes in POY section & from DRR -2 the melt comes at spinning as well as POY.

PARTIALLY ORIENTED YARN: -From DRR -1 it comes on packs and according to requirement the denier of yarn is settled. Thisyarn is finally bounded on winders. In this way partially oriented yarn is formed in this section.

SPINNING: -In this section the melt is converted into the toe according to the requirement of denier of fiber.This toe is then collected in the tank via can traversing process.

FIBRE LINE: -

Toe coming from spinning section is further comes under the effect of toe guiding machine, crimper, dipping bath, draw frames. Tow is crimped by crimper, washed at different temperature by the dipping bath, stretched by the draw frames and at last it is cut by the cutter according to requirement& is finally packed.

POLYMER PROCESS

RAW MATERIAL :

PTA - Pure Terephthalic Acid (HOOC-C6H4-COOH)MEG – Mono Ethyl GlycolCATALYST-Antimony Tri AcetateDELUSTRANT-TiO2

CATALYST PREPARATION:

In the glycol preparation section, catalyst req. for poly condensation is added to glycol. Glycol isheated in catalyst preparation vessel in order to improve solubility for catalyst. An amount of Poly condensation catalyst will be filled in catalyst preparation vessel. While the sol. Is stirred, catalyst is dissolved. After recheck of concentration by analysis the solution is passed through catalyst glycol ilter into catalyst EG-receiver

ESTERIFICATION:

PTA & GLYCOL are esterifies under graduate pressure & with rising temperature toTEREPHTHALIC DIGLYCO ester is formed while water is being split off. Together with water a part of free Glycol leaves the section & these two components are then sep. byDISTILLATION(1401).While Glycol is refluxed into the Esterification reactor 1(1201) & 2(1202), water is discharged into WASTE WATER SYSTEM. Esterification takes place in two series connected reactors.

DELUSTERENT PREPARATION(TiO2):-

TiO2 suspension is prepared in suspension vessel & homogenized in disperser& predetermined quality of glycol is passed via a flow meter into TiO2 Vessel to get 50% suspension

PRE POLYCONDENSATION: -

Products coming from EST. Section are Polycondensed under a rising vacuum at elevatedtemperatures. But in agitators are applied to ensure a more effective evaporation of glycol andincreased heat transfer due to turbulent flow of circulated product. At the same time, at a certainresidual Esterification reaction proceeds parallel to polycondensation reaction. Due to pressuregradient product flows to other stages w/out conveying equipment. The vessels for prepolycondensationreaction are 1207(stage 1), 1205(stage2) &1206(stage3)

PRE POLYMER VACUUM SYSTEM: -

Vacuum is drawn in Pre polycondensation reactors with the aid of blower glycol liquids ring pumps provided with spray condenser &Glycol circulation pumps. Glycol liquid ring pump is provided with separate glycol cycle. For recycling the glycol is conveyed to paste preparation vessel. Glycol stream is divided as under:-1. Main stream is passed to condensers being in operation.2. The partial stream is passed with the glycol liquid ring vacuum pump being operated, to Replace operating medium.

FINAL POLY CONDENSATION: -

Product leaving Pre polycondensation stage is polycondensed in polycondensation reactor under an increased vacuum, and at same time under elevated temp. To desired final viscosity. Product enters at the one DISC RING TYPE agitator. Disc rings are used for lifting up the product from the chambers & vapor of glycol is withdrawn under high vacuum so that a rapid reaction takes place in the product

LIQUID RING PUMP VACUUM SYSTEM: -

The gases &residual vapors are removed by way of suction from third jet condenser with the aid of following glycol liquid ring pump and compressed to atmospheric Pressure. The glycol coming out of process is recycled to paste preparation.

VACUUM JET SYSTEM: -

FINAL PRODUCT DISCHARGE PUMP:-

The non condensable gases coming from the scrapper condenser are withdrawn into EG jet system. The glycol vacuum generator consists of three series connector injector stages. Each stage being followed by a direct contact condenser in which all condensable are condensed with liquid glycol. Non condensable gases together with portion vapour are withdrawn by means of suction by injector stage following the condenser & compressor. Condensed glycol leaves direct contact condenser at lower most end & flows via gravity flow to glycol immersion vessel. Product being in DRR is divided into two product feed pumps into corresponding product streams. Both product feed pumps are driven by INVERTER CONTROLLED MOTORS on its way to DIE head. The product is passing through VISCOMETERS of DRR. GEAR PUMPS are fitted with heating jackets for the liquid from HTM plant. Discharge from DRR2 is fed to BOOSTER pump & move to POY stream.

CHIPS PRODUCTION: -

Some part of melt is converted into the chips from DRR-1.These chips are made so that in any case ofpoly failure, chips are melted and are used as the raw material.

.

SPINNING

SECTION

BRIEF DESCRIPTION OF SPINNING TECHNIQUES:

There are three main techniques of spinning: -

1 ) DRY SPINNING: The first spin able fiber was produced with this technique. Solution ofspin able fiber is made in solvent. Solidification of jet done by evaporation of solvent. 2 ) WET SPINNING : In Wet Spinning the polymer is coagulated in a bath containing a liquidthat is miscible with the solvent but is not itself a solvent of polymer.

3 ) MELT SPINNING: It involves freezing of molten polymer jet. It is simpler and is mostelegant method of producing filaments.

Man made fibers produced by different methods:-

TYPES OF SPINNING PROCESS:-

(CLASSIFICATION IS BASED ON SPINNING SPEEDS)

1. LOY (LOW ORIENTED YARN) Spinning : Low spinning speed in range of 600-1800rpm

2. P OY (PARTIALLY ORIENTED YARN) Spinning : Medium spinning speed in range of1800-4000 rpm

3. HOY (HIGHLY ORIENTED YARN) Spinning : High spinning speed in range of 4000 –6000 pm

4. FOY (FULLY ORIENTED YARN) Spinning: Very high spinning speed above 8000rpm.

Brief Description of AFL POY plant :

Total POY Capacity : 40 TPD

Technology of Plant : M/S ZIMMER AG GERMANY

Supplier of Winders : M/S BARMAG AG GERMANY

Total Nos of lines : 3 (SM#1, SM#2 & SM#3)

Total nos of positions/lin : 16

Total Ends / position : 8

Total Ends/ line : 128

PROCESS FLOW ACTIVITIES:

1 CPF: It is a continuous polymer filter which is used to filter impurities like oligomers, gels& black particles.

2. Booster Pump: This is a gear pump to supply polymer at constant pressure to POY.

3. Mix- Cooler: For cooling & homogenous mixing of polymer.

4. Melt Pump: This is a gear pump to provide metered quantity of melt.

5. Spin Pack: Assembly which filter impurities, distribute polymer pressure homogeneously.It consists spinnerets for filament extrusion.

6. Quench System: Filaments coming out from spinneret are cooled with help of cool crossflow air. Proper orientation of filaments takes place during quenching & properties are set.

7. Finish – System: This system provides metered quantity of spin finish to yarn.

8. Gadgets: Controls the yarn tension & facilitate achieving better quality package buildup.

9. Intermingling: Provides nips to yarn which facilitate better unwinding at Texturisingstage.

10. Winders : Automatic changeover of bobbins take place after a required preset time. Allpackages are produced with same weight with these winders.

SPIN PUMPS:-

Spin pumps are used to deliver metered quantity of polymer melt to Spin Pack as per the required Denier. Requirement is to deliver accurate quantity of polymer to each &every pack in very close tolerance. Planetary type gear pumps are used for this purpose. There is one inlet & four outlets to deliver melt. Speed pump speed is set through invertors

Supplier of Pumps: Mahr Gnbh Germany

SPIN FINISH: -

As the name suggests, Spin Finish is the finishing treatment given to yarn to facilitate the processability of yarn during its manufacture as well as in its subsequent processing at customers end.

WHY IS SPIN FINISH APPLIED?

_ Lubrication: controls friction_ Antistatic Property: Control static charge._ Cohesion of filaments: Control filament in bundle_ Antibacterial/anti oxidant agents

Where & How spin finish applied?

In POY: At Spinning stage only…Spin Finish is applied on yarn in metered quantity with help of Spin finish metric pumpthrough CERAMIC OILING NOZZLE in the form of emulsion of 5 to 10% conc. As perrequirement.

WINDING ACTIVITY:-

Type of Winders : CW4R (CRAFT WINDERS)Mechanical speed : 2 500 – 4500Helix Angle : 5 – 7 deg.

Package Weight : 15.5 kgs

Operational Speed (rpm) : 2700 – 3200Gadget type : Duo

Mechanical Speed (rpm) : 2500 – 4500

Overfeed : 0.4 – 0.6 %

Here SPW means Step Precision Winding.Helix Angle: Half of crossing Angle

PSF SPINNING

After Final Poly Condensation,. The melt flows to the Disc Ring Reactor. There are two Disc Ring Reactors (DRR1 & DRR2). Discharge from DRR2 is fed to Booster Pump in the POY stream and that from DRR1 goes to PSF SPINNING.

SPIN PACK:-

The incoming Discharge is pumped to the SPIN PACK in the metered quantity through the metering pumps & at a pressure of 170bar.From metering pump, melt goes to spin pack where the impurities are rendered out and polymer is distributed homogeneously. It consists of spinnerets for filament extrusion.

QUENCHING AREA:-

Melt from spin pack goes to quenching area where filament is cooled with cool cross air. In ittemperature of air is kept 16 deg/c and that of water is kept at 8 deg/c. Hence her ENTHALPY ofsystem is controlled.Then the filaments from all positions are collectively form a tow through Slub Catcher and Kiss Roll where the spin finish is applied which helps in cohesion.

GODET ROLLERS:-

These control yarn tension & help in building better quality. It has seven rollers run by invertermotors.

SUNFLOWER UNIT:-

After gadget rollers, tow is passed through Sunflower unit which provides crimps on reel so that tow does not entangle on falling in can. Its rolling speed is more than those of Gadget Rollers.Then tow is moved to Fiber Line for further processing.

FIBRE LINE OR DRAW LINE:-

Drawing is the process of aligning un-oriented molecules of polymer chain along the polymer axis & in turn increasing crystalline zone of polymer. Spun yarn in produced in spinning has poor orientation and is not suitable for textile applications. Hence it is drawn to convert it to acommercially useful product.

FIBRE LINE BROADLY CLASSIFIED IN 4 AREAS:-

1. DM#1. - Big line with an avg. production cap. 75 tons/day (ZIMMER TECHNOLOGY)2. DM#2. – Big line with an avg. production cap. 75 tons/day (ZIMMER TECHNOLOGY)3. DM#3. - Small line with an avg. production cap. 10 tons/day (ZIMMER TECHNOLOGY)4. DM#4. – Big line with an avg. production cap. 75 tons/day. ( Zeng -Zhou Technology)

PROCESS:-

CAN CREEL AREA:-

After creel gets ready from spinning, it is placed in fiber line creel area for at least 2 hrs ofconditioning as polyester un drawn filaments will attain moisture equilibrium as this will help inhomogenous drawing of filaments. Cans in creel will depend upon tow denier to be run.

TOW GUIDING FRAME:-

Set of cables is then passed through set of rollers called TOW GUIDING FRAME which is used togive cables the equal pre tension before making it ready for drawing.

DIP BATH:-

Tow is then passed through Dip Bath with rotating guide rolls; here the Dissolution conc. ismaintained 0.6% as spinning finish is washed off. In this bath all the cables pass through DM water sol. As this wets cable uniformly.

DRAW FRAME 1 & 2:-

Main drawing zone is comprised of 1st & 2nd set of 7 rollers each called DF 1 &DF 2. One nip rollereach is provided at DF1&DF2 to squeeze out extra moisture and to avoid slippage of tow. Processconditions are so selected that actual drawing point comes at bottom of 7th roll of DF1. The tow isdrawn around 2.6 times.DF1 is maintained at 40 deg/c & DF2 is at 90 deg/c. After 1st

drawing, 2ndstage drawing is b/w 7 rolls of DF2 & 1st 8 rolls of TSU-1 (annealer). This drawing is helped with aSTEAM CHEST. The speed of TSU-1 is about 1.15-1.2 times. Speed of TSU-1 is Line speed.

THERMOSETTING UNIT:-

Drawn tow is passed through TSU-1 & TSU-2 which heat stabilizes the tow to a specified shrinkage.A relaxation is given b/w TSU-1(first 8 rolls) and TSU-2(last 4 rolls) and again relaxation is given incooling zone b/w TSU-2 and DF3.A total of 3% relaxation is given. Steam pressure is decided as perthe dyeing and tensile properties. In case of DM#4 there are three TSU zones i.e. (1 to 6th roll)_,TSU-2(6th to 12th roll),TSU-3(12th to 18th roll).So there is relaxation b/w TSU-1& TSU-2 & TSU-3.Relaxation and cooling is between TSU-3 and DF-3.After heat setting zone there is quenching andcooling zone in which tow is cooled with DM water spray and a set of cooling rolls called DF-3. Thisfreezes the orientation and fiber of req. tensile properties is achieved.

CRIMPING:-

Crimps are basically waviness in the filaments which are helpful in further processing of fiber intextile industries for blending etc. Before entering crimper tow is passed through a stacker unit (set of3 rollers) to adjust 3 bands of tow as per the crimper requirements. Later it enters the crimper afterpassing through a STEAM BOX, which makes it ready for crimping by heating the tow with steam. Incrimper crimps are imparted through a stuffer box crimping method, in which there is a set of tworoller and two horizontal plates. Crimps are imparted due to high pressure of crisper rollers and stufferbox plates. In the crimper, finish is applied on the tow by injecting it through stuffer plates (top &bottom) itself. The finish application is must as it helps in further processing of fibre in TextileIndustries.

DRYERS:-

Tow that comes out of crimper is still wet & therefore passed through a hot air steam heated dryerhaving 5 zones. The temperature are set such that in final tow the moisture content is not more than0.5%.Crimps properties are also stabilized in dryer section. Temperature in dryer section is keptbetween 60-90 deg/c.

CUTTERS:-

Crimped &stabilized tow after cooling is next passed through tension adjusting rollers before cuttingso that crimps are removed but not overstretched. The cutter then cuts the tow to desired staple lengthagainst the pressure of pressure wheel.

BALING PRESS:-

Finally cut staple fibre is allowed to fall in bailer box through a duct, where bale is formed whichfinally is packed after being pressed with a pressure of 225 bar. Generally the bale weight is kept 350-380kgs.

RECYCLE

PLANT

RECYCLE PLANT IPCL, Chohal, Hoshiarpur (CAPACITY: 30 TPD)

This is a plant where small pieces of plastic bottles after crushing them are recycled to make fibre out of these plastic pieces. Hence here raw material is plastic pieces (flakes) and chips that are made during spinning.

Process of manufacture can be divided into following main two areas

1. Flakes conveying , drying & spinning2. Fiber Line

PROCESS: -

Flakes are conveyed to storage silo by PNEUMATIC conveying system. From this silo it goes to5 tumbler dryers each having 2.25Mt capacity, where flakes are dried, with steam and vacuumpulling, up tro req, level. From these tumbler dryer flakes/chips are transferred into two storagehoppers with help of conveying trolleys. PET flakes are melted in Extruder having six heating zones. The extruder maintains melt pressure at set value with variation in speed .The melt flows from extruder through Continuous Polymer Filter (CPF) to two beams. CPF has 200 mesh candles (19nos) in it. The CPF is heated with SENTOTHERM, which in term is heated by electric heaters. Melt flows from CPF to beams and to position through metering pump. The metering pump gives a metered quantity of melt. The speed of pump is set from inverter.Melt flows out from spinnerets in form of continuous filaments and is cooled byquenching air of which temperature is maintained at about 18 deg/c. Also quench air delta pressure is maintained in each position.Filaments of all positions collectively form a tow in the Take Up Unit. In Take upspin finish are applied to filaments on all positions individually. Spin Finish act as an anti-staticagent and also helps in cohesion of filaments in tow.

Take Up Unit has 6 Gadgets and Sunflower Reel unit. The gadgets surface speedis set according to DENIER and filaments are drawn by it. The Sunflower Unit gives temporarycrimping to tow so that tow falling in can does not cause tow enlargements.The tow falls into can. The can moves in to and fro movement and sideways onthe Can Traverse Unit helping in uniform filling of can.A creel is formed of no. of cans & is supplied to Draw Line.

DRAW LINE: -

All cans tow ends are collectively drawn over the Drafter Rollers in form of three bands. Here draws are given and total draw speed is controlled from Drafter Roller Speed.The tow is passed through the Dipping Bath to enable to draw it in wet state. The tow passes through the draw bath, b/w Drafter Roller-1 and Drafter Rollers-2,having DM water at about 70-75 deg/c. It helps in drawing the filaments in wet and hot condition. The tow passes through steam chest for proper drawing at Drafter rollers-3. After the draw rollers the tow converges into single band and passes through crimper rollers and stuffer box, which provides crimps to filaments.

The finish is applied to tow at tow conveyor and the tow passes through relaxer dryer, throughwhich the hot air is blown. The tow is cut into the desired staple length at the cutter reel. The cutmaterial is transferred to bailer by conveyor and is packed into the bales at the Baler

UTILITY

PLANT

UTILITY PLANT

1. BOILERS2. CHILLERS3. COMPRESSORS

BOILERS: -

Water requited by the industry should be soft and free from organic matter. Ifhard water is used uniform drying of the fiber is not possible. Hardness of water isremoved and then it is supplied to boilers for the production of steam. There are fourboilers in the plant from which two have been made by THERMAX (Pune) and other twoare made by IAFC (Bombay)

THERE ARE TWO TYPES OF BOILER:-

1. WATER TUBE 2. FIRE TUBE

WATER TUBE: -

In this case water flows from the tube and heating is done outside thetube. Two third of the tube is filled with water and heated so as to convertthe water into the steam

FIRE TUBE: -

In this case fire is within the tube and water is circulated around it,such that water absorbs the heat converts the water into steam.

In IPCL there are four boilers two of water tube type and two offire tube type

CHILLERS: -

Steam given out by generators is used to drive the chiller machine which produceschilled water and this chilled water is supplied to whole factory which serves as apurpose for coolant. Here arrangements have been made that the hot water comingthrough pipes from various machines and is cooled.

COMPRESSORS:-

In the Compressors, the compressed air is produced. There are total three no. ofcompressors in the factory which owe for the supply of compressed air. The compressedair being produced is supplied to machines through hollow pipes.

DIVISIONS

OF

PLANT

The plant is divided into five section namely:

Poly Poy Spinning Fiber line Recycling

There is a definite chance of launching another unit in the plant that is of CONJUGATE FIBER by next year. The main motive is to produce a high quality fiber , Which is in demand in European Countries .As I have already discussed that the factory has technical collaboration with Germany and China.

So we can say that the heart is poly , the production starts from this unit .if it comes to stand still, the company production does not proceed further .In this unit final product formed is polymer which is transferred to different section of the plant from Disc Ring Reactors(DRR1&DRR2).Disc Ring Reactors uses radioactive material for knowing its level . Raw material used up in this section are PTA (Pure Terepthalic Acid) and Glycol with Antimony Tri Acetate act as a catalyst. Titanium-di-oxide act as a delustrant .The other by product formed during this reaction is water.

POY is another section installed in the plant for the production of the Partially Oriented Yarn just to improve the strength of yarn. this is achieved in two stages:

SPINNING SECTION is another section where spinning of polymer results in

advancement of polymer paste or melt coming from DRR-2 in poly section through the various lines with the help of booster pump in the poly unit.

TAKE UP SECTION includes the windings of the yarn produced .It the yarn from the

spinning section and then wind up on the paper tubes with the help of WINDER MACHINE that is why it is known as take up section.

FIBER LINE is the place where production of fiber takes place. It is the last stage of

producing PSF(Poly staple fiber) after passing through the stage of polymer production in POLY section, and production of TOW in spinning section .After that through the various process final packing of fiber takes place in BAILING PRESS. It operates hydraulically. The

weight of each bail is 360kg with variation of 20kg.

There is recycle plant also where small pieces of plastic bottle after crushing them are recycled to make fiber out of these plastic pieces.

SOURCES OF RAW MATERIALS

1. PTA:

2. GLYCOL:

3. CATALYST:

4. TiO2

Reliance Hazira -Gujrat

Patal Ganga - Bombay

Reliance Hazira-IGL,IPCC

Mittal Polymer-Kota

Sahibabad -UP

Sachtleben - Germany

OVERVIEW OF PLANT

As an electronics Trainee my aim in six week trianing was to study the process going on in the plant. I wanted to know the sections in which plant is divided,what the raw material used and what the final product is.

DISTRIBUTION OF PLANT :-

PROCESS PRODUCTION/DAY PRODUCTION/YEAR

(TONS) (TONS)

POLY

POY

SPINNING

RECYCLING

260

35

170

31

94900

14000

5000

3000

ELECTRICAL

SECTION

INTRODUCTION

Electrical section of the curcial part of the industry. Since the plant runs for 24*7, so continuous power supply should begiven to the different section of the plant . two different types

of power supply of ALF are :-

1) DG (Diesel Generator) supply

2) PSEB (Punjab State Electricity board) supply

ALF is the process plant , so there is always a need of continuity of the power supply . to maintain this continuity , DG supply is given to essential and semi essential and semi essential load , while, PSEB supply is given to normal load. Essential and semi essential load are those loads where continuous power supply should be given in case of normal load, if the supply is switched off it can be restart. POLY, spinning, POY comes under essential load while , utility section comes under normal load. Running load required in case of essential & semi essential load is 4.8MW & 2.0 MW in case of normal load.

There is total six DG’s with four SKODA company having a capacity of 1.2MW (each) & two MAN company having a capacity of 2.7MW (each). PSEB supply is coming from chohal sub station has a supply of 132KV.

INDUSTRIAL SUBSTATION

The electrical substations are same as that of other substations. The main function of the substations is mainly to convert the voltage level of incoming voltage to other level in the outgoing voltage. In ALF , 33KV supply is coming to the switch yard. This incoming supply is coming from 132KV main substation chohal , Hoshiarpur. The substation was commissioned by siemens Ltd. In 1988.

The two 5MVA transformers are located in the main sub-stations yard. M/S cromton Greaves are the manufacturer of two transformers. Since the current is very high therefore ammeters cannot be used for the measurement. So, CT ( Current transformer) & PT ( po9tential transformer) are used for measurement of the current & voltages.

CURRENT TRANSFORMERS:-

They are used for measuring high current. Since the current in the load lines is very high therefore ammeters cannot be used. CT is basically the step down transformer connected in

series with the load line.

POTENTIAL TRANSFORMER :-

These are used for the measuring high voltages. Since, the voltage of the order of KV are produced & voltmeters of this range are not available so step down transformers are used to step down the voltage to the level of voltmeter.

CIRCUIT BREAKERS:-

Circuit breakers are the device which :-

1). Makes for breaks a circuit either manually or by remote control under normal condition.

2).Breaks a circuit automatically under fault condition.

Functions performed by the circuit breakers:-

1) To carry full load current continuously

2) To open & closed a circuit on no load

3) To make or break normal operating current

4) To make or break short current in faulty section

CLASSIFICATIONS OF CIRCUIT BREAKERS

The classifications of circuit breakers are follows:-

Oil circuit break

Air circuit breake

Water circuit breaker

Vaccum circuit break

Sulphur Hexa Flouride circuit breaker

INDUSTRIAL CIRCUIT BREAKER

Circuit breaker is a very important electrical equipment. It is used in almost every industry. In ALF the following circuit breakers are used :-

1) MOCB ( Minimum oil circuit breakers)

2) ACB ( Air circuit breakers)

MINIMUM OIL CIRCUIT BREAKERS :-

This type of circuit breaker is also known as poor oil or small oil circuit breakers. In this circuit breaker is small quantity of oil used for the excitation.

AIR CIRCUIT BREAKERS

In this circuit breaker, compressed air is employed for arc excitation. When contacts are separated, arc is struck; the air blast cools the arc & sweeps always the ionized medium established between the contacts, this

Increases the dielectric strength of the medium between the contacts and help in the restriction of the arc. Thus the arc is distinguished & current is interrupted.

EARTHING

The term earthing means connecting the neutral point of the supply system or the non current carrying parts of electrical apparatus to the general mass of earth in such manner that at all time an immediate discharge of electrical energy takes place without danger. Earthing is necessary as it offers many advantages given below:-

1). Better safety is ensured

2). Sensitive protective apparatus can be used.

Earthing is also called neutral grounding.

EARTHING USED IN INDUSTRY

Various methods of are present. Some of them are:-

1) Strip earthing

2) Rod earthing

3) Pipe earthing

4). Plate earthing

But in industry , plate earthing is used.

DIESEL GENERATOR HOUSE

Diesel generators are essential part of the process industry. These are used as the stand by power supply units. These power plants are in the range of 2-50MW capacity. The DG are more reliable and long piece of equipment compared with the other type of power plants.

ADVANTAGES OF DG

1) Design and installation is very simple

2) The stand by losses are less

3) Occupy less space

4) Can started & put on load quickly

5) Requires less quantity of water for cooling

6) Overall capital cost is less

APPLICATIONS

1) Used for the peak load house.

2) As the stand by unit.

As the emergency plant

FIELD INSTRUMENT

PREASSURE TRANSMETTER

There are two types of transmitters:-

1). Differential pressure transmitter

2). Absolute pressure transmitter

DIFFERENTIAL PRESSURE TRANSMETTER

These are force balance instruments, which measure differential pressure & transmit a proportional pneumatic output signal. The various forms of the transmitter provide capability for measuring differential span from 5 to 800 inches of water. The span or each transmitter is adjustable. A micrometer type scale on the span adjustment permits any previously calibrated span to reproduce without recalibration.

ABSOLUTE PRESSURE TRANSMITTER

These instruments measure absolute pressure & transmit a proportional 4 to 20ma DC electrical output signal.

LIQUID LEVEL TRANSMITTER

These are the instruments, which measure liquid level and transmit a proportional 4 – 20ma DC electrical output signal. they are used to control the amount of flow of liquid. The various types of transmitter provide capability for measuring level on closed tank or open tank

application.

RESISTANCE TEMPRETURE DETECTOR

(RTD)

It works on the principal of change in resistance with in change in temperature i.e. resistance of conductor changes when its temperature is change. This property is used for measurement of temperature.

The material used is generally platinum, gold, silver, copper. Platinum is suited for this purpose, as it can, with stand high temperature while maintaining excellent stability. As all metal produces positive change in resistance with temperature. This off course is the main function of RTD that system error is minimize. This implies a metal with value of resistivity should be used for RTD. The lower is the resistivity of metal the more material we will have to use.

The requirements of conductor material to be an RTD are as follows:-

1) change in resistance per unit change in temperature should be as large as possible.

2) resistance of material should have continuous & stable relationship with temperature.

INVERTER DRIVES

Inverters basically control the speed of motors according to the requirement of the plant. Most applications require accurate speed control and synchronous multi driven operation. AC motors are being used for search applications due to:-

1) AC motor are rugged low inertia & require less maintenance.

2) Maintenance cost is low due to absence of commutators & brushes.

3) Working voltages can be higher but for DC only 500V is used al AFL site.

4) 0.005 to 0.05% speed accuracy is possible in the digital speed control while 0.001% is possible with phase locking.

Reason for drive selection:-

1) Speed control accuracy is higher as compared to DC drives.

2) Wide control range and reliability is better.

3) AC drives are more reliable than DC drives.

Speed of the induction motor:-

S = 120 *F / P

F = supply frequency

P = Number of poles

So speed can be controlled by

1) controlling freq.

2) controlling no. of poles

INVERTER DRIVER USED IN AFL

Fiber line broadly classified in 4 areas:-

1) DM#1 = Runs on DC drivers ( SIEMENS TECHNOLOGY).

2) DM#2 = Runs on DC drivers ( SIEMENS TECHNOLOGY).

3) DM#3 = Runs on DC drivers ( SIEMENS TECHNOLOGY).

4) DM#4 = Runs on AC drivers ( FINLAND TECHNOLOGY).

There are 7 DC motors ( tow guiding frame, DF1, DF2, Roller TSU, TSU2, DF3 & finished unit) in each DM#1, DM#2, & DM#3 & all these motors runs on dc drivers. There are 9 AC motors (tow guiding frame, draw standing (DS) 1, DS2, Annealer (ANN1), ANN2, ANN3, DS3, Three roller and crimper) in DM#4 and all these motors runs on AC drivers.

INVERTERS APPLICATIONS

The inverter & motor requirements are determined by the speed range and torque requirements of the load . the relationship between speed & torque for different loads depend upon constant torque loads or variable torque loads.

Constant torque (CT)

CT is used if the application needs a constant torque on the whole freq. range. Many loads such as conveyers, compressors and positive displacement pumps can be considered to be constant torque loads .

Variable torque (VT)

VT is used if the application has a parabolic freq. torque characteristics like many fans & pumps.

PLC

PLC

(PROGRAMMING LOGIC DEVICE) PLC USED -- SIMATIC 5S- 135U

PLC are suitable for automation tasks in medium and upper performance level.

Provide simple solutions to AUTOMATION tasks such as:-

Logic Control PID Control Co-ordination & Communication Operator Control Monitoring Signalling Listing

Controllers are suitable for Areas as:-

Machine Control System Process Automation Process Monitoring

It has high performance capabilities:-

Easy to use due to simple assembly & connection. Simple communication with other programmable controllers & components through use

of internal Communication Processors & Bus System. Adaptability through use of Different I/P & O/P Voltages and as well as Modular

expansion. Simple programming by means of Structured Programming & use of standardized

programmable sections. Easy system start up by means of Programming & Debugging aids.

Language used is STEP-5 with following methods of representations

Control System Flowchart ( CSF) Ladder Diagram (LAD) Statement List( STL) Graph 5 - for sequential control

S 5 – 135U Programmable Controller:-

The S 5 – 135u programmable controller is a multi processor controller with special purpose processors which are available in various combinations each with a programmable memory:-

A. BOOLEAN(S) PROCESSOR:- Primarily used to open loop or logic control, monitoring and signaling

B. LOOP(R) PROCESSOR :- Primarily used for arithmetic functions , closed loop or PID control, monitoring & signaling.

C. COMMUNICATION PROCESSORS:- For operator process communication and Monitoring and Communications with other systems

Each processor uses same operation set and is optimized for particular tasks it has to perform.

By using a no. of R and S processors, automation task can be broken down into manageable parts.Each processor executes its program of the other processors. This increase the overall processing rate.Each processor can be started independently of others.

PERFORMANCE FEATURES :-

Central controller always contains a power supply unit and central controller modules.Expansion units are available both with or without a power supply. Depending upon a automation task, different I/P and O/P modules can be plugged into PC.

A. Digital I/P & Digital O/P ModulesB. Analog I/P & Analog O/P ModulesC. Communication Processors.

Digital I/P & O/P Modules Digital I/P &O/P Modules are adequate for simple logic control in which only state “0” &” 1” occur

Analog I/P &O/P Modules If on other hand, constantly changing modules quantities such as temperature or pressure are to be processed, Analog I/P & O/P Modules become necessary.

Communication processors Various Communication processors are available for automatically handling data communication b/w PCs & other devices such as Printers ,CRTs,.By performing these tasks, communications processors offload the CPU

Intelligent I/O Modules Intelligent I/Os may be used to solve automation tasks in which signals…. …or signal levels of a particular type occur & must be processed rapidly & frequently. These modules operate to a large degree independently of the CPU & also help to offload it . These modules can be used for example :- for position decoding, temperature control or high speed counting.

MECHANICAL FEATURES:-

Central controller & expansion units consists of

A. Compact housingB. Power supply chassis with fans and a battery compartment( for RAM)C. 21( 20or 11) Module slots

Housing:-

The housing consists of bolted aluminium sections with ventilation openings at top and bottom.The slots have socket connectors and guides to accommodate the modules.

Wiring duct for signal cables runs along the front beneath the modules and above

power supply chassis.

Power Supply Chassis :-

It with two fans is located at bottom of Housing.

Input Voltage is 240V AC.

Output voltages for internal power supply to modules:

+5V(10A,18A,40A;short ckt proof),with jacks for measuring current and voltage,

+24V(0.8A,2.8A:fused), with jacks for measuring voltage,

+15V(can be used for special applications)with jacks for measuring voltage.

Monitoring facilities (with LED displays) are provided for

A. input voltage(no display)B. 5V,15V,24V(+ OR -) O/P voltageC. 3.4V(+ or -) back up battery voltageD. airflow for both fansE. 24V(+ or -) load voltage(external).

Back Up Battery:-

A Lithium battery is provided to supply power to all RAMs in event of power failure.

S Comm.Proces-

ssor

Coordi-natorR

Program-er

Process computerOther PCsPrinters

CRTs

4321

Memory sub module

S 5 BUS

a b c d

EU Interface

1 – Binary signal a – digital I/ps d – analog o/ps 2 – Binary amplification b - digital o/ps3,4 – D/A Converter c – analog I/ps

Battery Characteristics:-

A. 10 year shelf lifeB. 5Ah capacity

Two jacks are provided for an external back up battery.With this feature, battery can be replaced w/out interrupting back up voltage even when I/P voltage is switched off.

The power supply chassis can be replaced w/out disconnecting the back up battery from central

controller.

STRUCTURE OF S5-135U PROGRAMMABLE CONTROLLER:-

Central Controller:-

Following modules can be plugged into central controller as required;

A. S ProcessorsB. R ProcessorsC. Communication ProcessorsD. Co-ordinator (if more than 1 processors used)E. Modules for I/P & O/P of digital and analog signals;F. Interface Modules for expansion units

Multi Processor Technology:-

A no. of processors can be usedin 135U central; controller, depending on task involved. A coordinator assigns time of accessing S5 bus to each processor. The necessary data exchange between all modules takes place via coordinator. Data exchange b/w all modules take place via S5 bus.

R & S Processors:-

R & s processors have a same operation set. However ,each processor is optimized for its specific tasks(eg. Processing speed).

The Automation task can be broken down into manageable sections by using a no. of R & S Processors. Each processor executes its program independently of the other processors.This inc. total processing rate.Each processor can be started independently of others.

The user program is stored in RAM or EPROM sub modules.One memory submodule can be inserted into each processor..During each program scanning cycle, the processor reads statements in program memory, interprets these statements and executes the corresponding operations.

Before each scan, input signal states are first transferred into the memory for process, input image. The processor accesses this memory during program execution. The processor stores signals for o/ps during program execution initially in memory for process o/p image. At end of each program scan, this image is transferred to outputs. Processor also handles internal timers and counters.

Communication Processors:-

Maximum of eight, each with two interfaces handle data communications autonomously with following:-

A. Standard peripherals such as printers, keyboards and CRTsB. ComputersC. Other programmable controllers,

The data req. for text and graphics can be programmed for each communications processors in a RAM or EPROM submodule so that they do not load the processor memories.

PROGRAM FEATURES:-

Programmable controller S5-135U

Basic function AND,OR logic,counting,timing,load & transfer operations; byte, word processing; comparison operations, 4 basic arithmetic operations for fixed pt. And floating pt. Nos; Integrated shift register &PID control algorithm

Programming language STEP 5

Processors S Processors( 1,8 bit optimized for LOGIC

tasks;

R Processors(optimized for PID tasks)

Scan time for 1K bit statements approx.

For 1K byte statements approx.

1.3ms in S Processor

20 ms in R Processor

45ms in S Processor

16ms in R Processor

Programmable memory(RAM, EPROM) 32K statements(data words) in each processor(R or S)

Flags 2048 for each R or S Processor

Timers 128 in each Processor

Inputs Digital Max.

Max

Analog Max

1024 with process image

3072 w/out process image

192

Outputs Digital Max

Max

Analog Max

1024 with process image

3072 w/out process image

192

POWER SUPPLY:-

Power supply is one of most important factors in determining long term reliability of PLC.For the safe and reliable operation of a PLC,an un-interrupted power, virtually free of frequency variation and voltage dips,surges and transients is essential. Failure of Power Supply can have varying from inconvenience in handling and catastrophic break down of equipment. Excessively large voltage impulses,Noise bursts and inadequqte filtering may result in component voltage overstress in the premature triggering of Control Circuit elements.

Power supply is an integral part of PLC and is generally mounted in main frame enclosure.Line power at 230V,50 Hz or 115V,50 Hz is converted to appropruate DC voltage required solid state memory and circuitry.For expanded I/O an additional heavy duty power power supply is usually required. Where overall size of system demands more than one power supply. It is desirable and in some case essential- for both supplies to be interlocked. If this precaution is not observed, a condition may arise where if a fault is introduced in one power supply, the logic would be left operational with possibly correct information but incomplete logic

Long or short power supply interruptions resulting in loss of stored information are liable to occur for many different reasons on any control system. For volatile memories where this condition could arise, DC cells are provided to ensure retention of memory in case of power supply failure.

Power is generally designed for a controlled power down sequence in case line power is lost. In case processor stops solving logic and retain the status of all coils, inputs, outputs and registers. Outputs are turned off. This eliminates the possibility of failure in an un determined mode. In power up sequence, stored inputs, outputs ,status of coils and registers are checked and only then memory scan sequence is actuated.

An ideal specification for a PLC power supply would include high speed automatic tripping with manual resetting for high current fault conditions such as accidental short circuits ,and time responsive overload protection against transient surges.

MEMORY:-

It is storage area which is used to hold program to be used by processor.It stores information until it is needed.Memory device must be extremely immune to noise & versatile. Size of memory is a function of total no. of i/o to be controlled.Basic unit of storage within memory is called word. Memory sizes are usually expressed as multiples of 1024 words,for eg. 1k,2k and so on ,where k equals 1024.Memory should be carefully selected after evaluating present and future needs.Solid state memories are of Two types:- static and dynamic.Static memories are bistable where information is stored in either of two states. It remain in a state until changed by an external signal . A flip flop is a common form of static memory. A dynamic memory ckt uses ‘1’ or ‘0’ in form of capacitor leakage and recharge.

PROMS:-

In any memory, it must be possible to read state of every binary word.If the binary word can be read but not changed,memory is called ROM.PROM is semiconductor type memory.It is non volatile,inexpensive and has good noise immunity.Electrical alteration is possible via a programme PLCs with electrically alternable read only memory EROM are desirable because it is possible to add a program or to stop or revise an existing program.

RAM:-

It is a semi conductor memory. A memory is said to be randomly accessible if individual binary words within memory can be accessed directly.It is flexible,inexpensive and has good noise immunity.It is volatile and requires battery back-up in case of power failure. Generally NiCd rechargeable cells are provided to ensure that program is not lost on power failure. Some models of PLCs offer a combination of RAM & PROM. In these PLCs, program is first developed on RAM and then transferred to PROM. Some PLCs use a portion of memory for executive program which reduces available memory for the control program. Hence memory of PLCs are checked before installation.

Devices used in PLCs as memory elements include magnetic cores and solid state devices.

SEMICONDUCTOR MEMORY:-

Most PLCs now use semi conductor memory.The solid state memory devices have the capability of capturing and retaining short term events.These devices also have the capability of being cleared or reset. In any memory, binary bit storage location must be addressible.If the contents of the memory can be changed as well as read ,it is read/write memory.

PROCESSOR:-

It is central control unit of PLC. It directs the controllers to perform its functions as a system. The I/O structure is that portion of PLC which permits the CPU to be connected to the manufactured process equipment.It receives instructions from memory and generate commands to the o/p modules.Input commands, devices status and instructions are converted to logic signals.These logic signals are taken and processed by processor.

Available PLCs are based on various microprocessor chips which are programmed with a main ‘EXECUTIVE PROGRAM’. The executive program enables processor to understand i/p command instructions and status signals, besides providing logic processing capability.These capabilities include simple AND OR logic, timing sequence,counting,arithmetic functions,decision making,manipulation and structuring data in arrays and even PID control on analogous i/ps.These capabilities offer more sophisticated control systems, such as control of parameters like pressure,temp.,level flow rate etc.These signals generated by processor are used either to turn on/off valves, lights of communication displays or to adjust set points of analo controllers.Processor allows each network of interconnected logic elements to occur in their numerical sequence in order they are programmed.First network is scanned at time when power is supplied,first from top left to bottom left and then continuing to next vertical column to the right.Within a network, logic elements are solved during scan and then coils are appropriately energized to complete the scan. Since scanning rate is of order of few milli seconds, all logic appears to get solved simultaneously.The result of each network scan is then available to all subsequent networks.Thus all i/ps and o/ps are updated once per scan.To communicate these i/p and o/p signals, storage registers act as bridge b/w signals at field levels and ckt of processor.

PROGRAMMER :-

Programmer transforms the control scheme into useful PLC logic. THE logic program is then stored in memory where it is made available to processor for logic operations.LCD and CRT programmers are very popular. Program can also be stored in cassette tapes and loaded into the

PLC through a special interface units.

A.) LCD PROGRAMMER:- It is compact and light weight for convenience in testing and for maintainance.It has the following functions:-

I. Programming adding, deleting and alteringII. Supervising

III. Read outIV. SimulationV. Debugging

VI. Storing and read out of programVII. Recording, loading and verifying the program.

B.) CRT PROGRAMMER:- Many sophisticated programmer based on a portable CRT console have been developed for PLCs.A CRT Programmer has the

following functions:-

I. Programming,adding,deleting and alteringII. MonitoringIII. SimulationIV. SearchV. Fault diagnosisVI. Program printoutVII. Verification of program

Special back lighted keys with contact, coil and engraved branch symbols make program entry straight forward. With these programmers,one or more programs can be made to display at same time, providing operator picture of ladder diagram. Program state is displayed on CRT programmer in form of power flow showing sequence operations at a glance.This enables the user to check accuracy of program.Thus trouble shooting becomes quite easy. R/W Memory helps to modify program before entering it in main memory.

Usually a CRT programmer incorporates a microprocessor in its design.As a result, program diagnostics,program labeling and print out facility are available. Any i/p or o/p signal can be forced on or off for simulation with DISABLE and FORCE KEYS, ENTER key force data processing programs easily. In the supervisory mode, following operations can be accomplished.

STOP : PLC scanning is halted

START : PLC scanning is restarted

CLEAR MEMORY : Memory contents deleted

CONFIRM : Checks completion of above operations.

The CRT programs are provided with approximately 70 messages to notify programming steps or processes malfunctions on display.

For Example: -

“ COIL IS USED “ : Coil already in use is selected forProgramme.

“ INVALID “ : Incorrect contact no. Is selected for Program.

“ MUST BE COIL “ : Contacts are selected for program Where coils should be programmed.

PROGAMMING LANGUAGE:-

There is no need to learn sophisticated programming language to program a PLC.The language used to program an PLC is an electrical ladder diagram with logic line numbers and standard relay symbols for ND/NC contacts, timers counters etc. A logic control program closely resembles the format used for electrical relay systems. In the ladder diagram, the vertical up rights of the ladder indicates the source of power. The horizontal rungs indicate switch contacts to control the flow of power. Generally, the logic program diagram elements use the same number designations as the conventional relay diagram. For step controlled events, a single input contact is used to control many contacts by assuming the same reference number, as if it were limited poles into each step. This affects not memory usages for a given ladder; schematic some PLCs can be programmed only one horizontal rang at a time. Their maximum number of vertical elements is also limited.

The control logic changes are carried out by addressing the particular program step. During the period outputs can be lock into an energized or de energized position. The logic program lines are designed with seal circuits for momentary contact inputs or with latch ckts for retentive output action in case of power failures. By assigning the same reference number, as if it were relay with unlimited poles. The diagram shows a conventional ladder diagram with and another figure shows its PLC equivalent.

PROGRAMMING:-

Programming a PLC is very simple and straightforward process. Program consists of relay contact and coil symbols interconnected in a ladder diagram type structure. To program a PLC, the designer first layout a ladder diagram of the control scheme. Each field input device is assigned an input address. Output relay coil numbers are assigned for solenoid, valves, motors, indicator lights and alarms, where required. The programmer is plugged into the service port of

the PLC. The program is then entered in to the memory manually, one run at a time, by the push buttons of the programmer, which are, marked with the same symbols on the four relay contacts types.

The line number and individual contact reference number are dialed on a thumb when. One of the push buttons, marked with the logic symbol is then selected and processed. PLCs have different limitations, on the number of horizontal and vertical contacts that can be programmed. The Inputs controlled by the program adjust the correct processing always by moving the set points of the analogue controller .the logic system can program the final set point position by comparing the programmed set point signal to the measurement signal from the process. These signals are interlocked to prevent the sequence from advancing to the next step until the measurement has reached the pre programmed, set point.

INPUTS/OUTPUTS INTERFACE:-

One of the characteristics of PLCs is the case with which they handle information at low power levels. Although it is desirable to handle information with a minimum of power dissipation, it is usually inconvenient to transmit signals at low power levels. TheControl of environmental conditions outside the PLC is seldom as good as that which can be specified within the PLC cabinet. Most of the input and output devices may already exist on machines and equipment and their design has probably been dictated by exacting mechanical requirement rather than suitability for any particular type of control system. This situation is resulted in the development of different types of inputs / outputs modules. One of the main characteristics that had made PLCs extremely attractive is that the input/output modules are designed to interface directly with industrial equipment. In some models of PLC s the input/output modules are directly connected to the main frame, while in others these can be remotely located if the processor is kept in a Central control Room. Inputs and outputs are connected to the PLC via I/O modules, each modules being capable of taking 1 to 16 inputs/outputs. The use of distributed inputs and outputs located near the input and output devices in case of plants spread over relatively large areas can reduce the wiring costs.