iffco training report

A

Report onIndustrial training

At

Kasturi Nagar, Gandhi Nagar, Gujarat, INDIA

Submitted to: Mr. B. A. Shah

Indus Institute of Technology and Engineering

Submitted by:Embrandiri Sujit

Sudeheshna Siddavaram

CERTIFICATE Indus Institute of Technology & Engineering,

Rancharda

This is to certify that following candidate of Electrical & Electronics Engineering (EEE) from has completed his 7th semester Training work in the year 2011 during 4th June ’12 to 12th June ’12.

Name: Embrandiri Sujit Sudheshna Siddavaram Reg.no.:090250108035 090250108063 Roll No. 09BEER011 09BEER059

Staff in charge:Prof. S.P. YadavHead of DepartmentElectrical & Electronics Engg.


ACKNOWLEDGEMENTI wish to express my gratitude to the Instrumentation Department & Electrical Department of Indian Farmers Fertilizers Co-operative Limited for allowing me to study various functions of their department.

It gives me an opportunity to understand the practical aspects of different functions of Instrumentation Department & Electrical Department of Indian Farmers Fertilizers Co-operative Limited. The present project bears the true justification of their investment. I would like to add few heartfelt words for the people who were part of this project in numerous ways.

It is my great pleasure to express my sincere gratitude to Mr. B.A. Shah , D.G.M. Training Department, IFFCO, Kalol Unit for his deep interest profile inspiration, valuable advice during the entire course of vocational training.

I also thankful to Mr. __________________, Head of Electrical Department and Mr. ____________________, Head of Instrumentation Department for taking interest and guidance in my endeavor to get opportunity to work at IFFCO.

I am also thankful to entire staff of IFFCO, Kalol unit for their help and assistance during my training period.


ContentsAbout IFFCO..................................................................................................................................................5

Production....................................................................................................................................................7

Ammonia Plant..............................................................................................................................................8

Plant Modifications.......................................................................................................................................9

Fire and Safety Department........................................................................................................................12

Locations and types of emergency..........................................................................................................12

Emergency siren code.............................................................................................................................13

Instrumentation Department......................................................................................................................14

Introduction to PLCS...............................................................................................................................14

PLC Origin................................................................................................................................................14

Programmable Logic Controllers.............................................................................................................15

I/O Circuits..............................................................................................................................................21

Basic Function of a Typical PLC................................................................................................................25

PLC Communications...............................................................................................................................26

Serial Communications............................................................................................................................26

Examples of PLC Programming Software................................................................................................28

Electrical Department.................................................................................................................................29

Electric power supply system..................................................................................................................29

Energy Consumption...............................................................................................................................30

Energy Saving Project..............................................................................................................................30

Energy Policy...........................................................................................................................................31

Important schemes implemented for performance....................................................................................32


About IFFCO

During mid- sixties the Co-operative sector in India was responsible for distribution of 70 per cent of fertilisers consumed in the country. This Sector had adequate infrastructure to distribute fertilisers but had no production facilities of its own and hence dependent on public/private Sectors for supplies. To overcome this lacuna and to bridge the demand supply gap in the country, a new cooperative society was conceived to specifically cater to the requirements of farmers. It was an unique venture in which the farmers of the country through their own Co-operative Societies created this new institution to safeguard their interests. The number of Co-operative Societies associated with IFFCO have risen from 57 in 1967 to 39,824 at present.

Indian Farmers Fertiliser Co-operative Limited (IFFCO) was registered on November 3, 1967 as a Multi-unit Co-operative Society. On the enactment of the Multistate Co-operative Societies act 1984 & 2002, the Society is deemed to be registered as a Multistate Co-operative Society. The Society is primarily engaged in production and distribution of fertilisers. The byelaws of the Society provide a broad frame work for the activities of IFFCO as a Co-operative Society.

IFFCO commissioned an ammonia - urea complex at Kalol and the NPK/DAP plant at Kandla both in the state of Gujarat in 1975. Another ammonia - urea complex was set up at Phulpur in the state of Uttar Pradesh in 1981. The ammonia - urea unit at Aonla was commissioned in 1988.

In 1993, IFFCO had drawn up a major expansion programme of all the four plants under overall aegis of IFFCO VISION 2000. The expansion projects at Aonla, Kalol, Phulpur and Kandla were completed on schedule. All the projects conceived as part of VISION 2000 had been realised without time or cost overruns. All the production units of IFFCO have established a reputation for excellence and quality. Another growth path was chalked out to realise newer dreams and greater heights through Vision 2010. As part of this vision, IFFCO has acquired fertiliser unit at Paradeep in Orissa in September 2005. As a result of these expansion projects and acuisition, IFFCO's annual capacity has been increased to 3.69 million tonnes of Urea and NPK/DAP equivalent to 1.71 million tonnes. In pursuit of its growth and development, IFFCO had embarked upon and successfully implemented its Corporate Plans, ‘Mission 2005’ and ‘Vision 2010’. These plans have resulted in IFFCO becoming one of the largest producer and marketeer of Chemical fertilisers by expansion of its existing Units, setting up Joint Venture Companies Overseas and Diversification into new Sectors.

IFFCO has now visualized a comprehensive plan titled ‘Vision-2015’ which is presently under implementation.

IFFCO has made strategic investments in several joint ventures. Indian Potash Ltd (IPL) in India, Industries Chimiques du Senegal (ICS) in Senegal, Oman India Fertiliser Company (OMIFCO) in Oman and Jordan India Fertiliser Company (JIFCO) are important fertiliser joint ventures. As part of strategic diversification, IFFCO has entered into several key sectors. IFFCO-Tokio General Insurance Ltd (ITGI) is a foray into general insurance sector. Through ITGI, IFFCO has formulated new services of benefit to farmers. 'Sankat Haran Bima Yojana' provides free insurance cover to farmers along with each bag of


IFFCO fertiliser purchased. To take the benefits of emerging concepts like agricultural commodity trading, IFFCO has taken equity in National Commodity and Derivative Exchange (NCDEX) and National Collateral Management Services Ltd (NCMSL). IFFCO Chattisgarh Power Ltd (ICPL) which is under implementation is yet another foray to move into core area of power. IFFCO is also behind several other companies with the sole intention of benefitting farmers.

The distribution of IFFCO's fertiliser is undertaken through over 39824 Co-operative Societies. The entire activities of Distribution, Sales and Promotion are co-ordinated by Marketing Central Office (MKCO) at New Delhi assisted by the Marketing offices in the field. In addition, essential agro-inputs for crop production are made available to the farmers through a chain of 158 Farmers Service Centre (FSC). IFFCO has promoted several institutions and organisations to work for the welfare of farmers, strengthening cooperative movement, improve Indian agriculture. Indian Farm Forestry Development Cooperative Ltd (IFFDC), Cooperative Rural Development Trust (CORDET), IFFCO Foundation, Kisan Sewa Trust belong to this category. An ambitious project 'ICT Initiatives for Farmers and Cooperatives' is launched to promote e-culture in rural India. IFFCO obsessively nurtures its relations with farmers and undertakes a large number of agricultural extension activities for their benefit every year.

At IFFCO, the thirst for ever improving the services to farmers and member co-operatives is insatiable, commitment to quality is insurmountable and harnessing of mother earths' bounty to drive hunger away from India in an ecologically sustainable manner is the prime mission. All that IFFCO cherishes in exchange is an everlasting smile on the face of Indian Farmer who form the moving spirit behind this mission.

IFFCO, to day, is a leading player in India's fertiliser industry and is making substantial contribution to the efforts of Indian Government to increase foodgrain production in the country.


Production

Production Unit : Kalol

State Gujarat, IndiaState Capital Gandhi Nagar, is about 18 Km from the plant site.District GandhinagarDistance from New Delhi 912 KmDistance from Mumbai 514 KmNearest Airport Ahmedabad (About 25 Km. away from Plant)Railway Station Kalol (7 Km from the plant)Road Ahmedabad (25 Km from the plant)On Ahmedabad- Mehsana State Highway (SH)Area under Plant 96 HectaresTownship 22 HectaresTemperature ( o C ) 45 (Maximum) in summer to 4 (Minimum) in winter.Rainfall (mm) 742Longitude 72-31-40Latitude 23-12-3

Production Capacities Ammonia- Urea Complex Commissioned in 1975 Ammonia - 0.36 million TPA Urea - 0.55 million TPA


Ammonia Plant

The Ammonia Plant is designed to produce 1100 tonnes of ammonia per day based on MW Kellogg steam reforming of natural gas process. Original plant capacity was 910 tpd, which is upgraded to 1100 tpd in the year 1997 with an add on Naphtha Pre-reformer unit (equivalent to ammonia production of 250 MTPD) to use the naphtha as feed stock alongwith natural gas. Presently, operation of Naphtha Pre-reformer is stopped as per guidelines of GOI. Presently, Ammonia Plant operates with 100 % gas as feed and fuel. Feed gas is first purified in the Desulphuriser -Activated Carbon and then mixed with steam, and this natural gas & steam mixture is partially reformed in Primary Reformer. A mixture of gases, coming out from Primary Reformer, enters Secondary Reformer where stoichiometric quantity of air is introduced.

The process gas leaving the Secondary Reformer contain nitrogen, hydrogen, carbon monoxide and carbon dioxide. At exit of Secondary Reformer, high pressure (HP) steam is generated with process gas. Then these gases are passed through Shift Converters (i.e. HTS, LT Guard & LTS) where most of the carbon monoxide gets converted to carbon dioxide. Carbon dioxide from process gas removed in CO2 Removal System where carbon dioxide is absorbed in an activated Methyl Diethanol Amine (aMDEA) solution.

Activated Methyl Diethanol Amine (aMDEA) solution from CO2 Absorber is letdown to HP Flash Vessel through hydraulic turbine. The aMDEA solution from HP flash is further letdown to LP Flash Vessel . The offgases from HP Flash Vessel is recycled back to CO2 Absorber.The solution in LP Flash Vessel is known as semi-lean aMDEA solution. The semi lean solution from LP Flash Vessel is pumped back into CO2 Absorber and CO2 Stripper. The aMDEA solution regeneration heat in CO2 Stripper is supplied by LTS exit process gases after heat recovery in BFW preheater. The vapor from CO2 Stripper is sent to LP Flash Vessel and off gases from LP Flash Vessel is further cooled & sent to Urea Plant as CO2 Product .

The process gases from exit of CO2 Absorber are again purified in the Methanator where the remaining small quantities of carbon oxides are converted to methane. The gas after purification is a mixture of mainly nitrogen and hydrogen in 1:3 proportion. Ammonia Dehydrator unit is installed to removed the oxygenated compound like CO, CO2 , H2O etc from syn gas at first stage discharge of Syn Gas Compressor. Liquid ammonia at -32 degC is used for washing the syn gas at Ammonia Dehydrator. The final stage discharge of Syn Gas Compressor is sent to two Ammonia Synthesis Converters. In Synthesis Converters, nitrogen and hydrogen combine to form ammonia and then syn gas passed through a train of coolers & chillers to condensed the ammonia formed in converted and un converted syn gas is recycled back to Syn Gas Compressor.

A small stream of gases being purged from the synthesis loop is sent to the Purge Gas Recovery Plant where hydrogen is recovered by cryogenic process. This hydrogen is recycled to the synthesis loop and balance is used as fuel in Primary Reformer Furnace. The separated liquid ammonia is purified by further flashing in Ammonia flash drums and it is then sent to Urea Plant or to an Atmospheric Storage Tanks, having 10,000 or 5,000 tonnes capacity. Basic Technology

UREA PLANT MTPD 1650 M/S STAMICARBON BV, THE NETHERLANDSDRY ICE MTPD 6 M/S BORSIG, GERMANY


Plant Modifications

Ammonia Plant

PGR Plant May 1980

Combination type auxiliary boiler burners Jan 1981

Natural gas compressor Aug 1984

Additional surface condenser Aug 1984

Installation of BFW coil in LT convection zone May 1986

Ammonia converter retrofit Sep 1993

LTS catalyst reduction system Sep 1993

Natural gas booster compressor Aug 1997

Naphtha pre-reformer system Aug 1997

Process air compressor revamp May 1997

MEA solution swap by MDEA in CO2 removal May 1997

Syn. gas compressor suction chiller Aug 1997

DCS control system Aug 1997

Ammonia recovery unit Dec 1998

Syn. compressor topping turbine nozzle modification Apr 1999

Installation of LNG piping system for use of R-LNG as feed & fuel May 2004

Installation of LTS Guard Bed and BFW Preheaters Jun 2005

Two Stage aMDEA CO2 Removal System Jun 2005

Installation of Ammonia wash unit (Dehydrator) May 2006

Installation of S-50 Ammonia converter at d/s of existing converter May 2006

Re-piping of synthesis loop May 2006

Revamp of synthesis gas compressor (LP & HP cases) May 2006

Additional rows of offsite BFW coil at ID fan suction for heat recovery May 2006

Urea Plant

LP absorber for HP scrubber off gases Mar 1978

Urea recovery system Feb 1981

Atmospheric ammonia scrubber for LP system vent gases May 1986


Fluidised bed Urea prills cooling system Aug 1988

Hydrolyser stripper system Dec 1992

Centrifugal CO2 compressor Aug 1997

High efficiency reactor trays Aug 1997

Additional LPCC Aug 1997

Pre-evaporator system Aug 1997

New second stage evaporator, condenser, ejectors etc. Aug 1997

Modified prill bucket Aug 1997

DCS control system Aug 1997

Ammonia recovery from LP system vent gases 1998 - 99

9 ata steam tracing change over to LP steam May 1999

Ammonia recovery from flash tank condenser off gases May 2001

Replacement of HP Stripper Apr 2002

Others

Extension of cooling tower with C.W. pump May 1978

BHEL steam generation plant Oct 1982

Additional streams of cation, anion and MB Mar 1986

5000 t ammonia storage facility Sep 1992

Inert gas/cracked gas plant Sep 1993

Additional Naphtha storage facility Aug 1997

Condensing turbine for C.W. pump Aug 1997

Cooling tower three cells with C.W. pump Aug 1997

2.2 MW DG set Aug 1997

Automatic bagging machine Apr 1999

New fire hydrant system Apr 1999

Renovation/addition of borewells Apr 1999

Dust extraction system for B & MH plant Apr 1999

Additional bagging packer in B & MH Plant Mar 2005

Modification in BHEL Boiler Burners for 100% MCR in Gas/LSHS Jun 2005


Fire and Safety Department

IFFCO has established procedures to conduct safety meetings, safety audits, and Risk assessment to identify potential accidents and emergency situations in the plant.The emergency situations, which have the potential to cause serious injuries or loss of lives, damage to property and serious disruption inside and out side the organization or to environment have been identified as FIRE, EXPLOSION and TOXIC RELEASE due to bursting of any of the high pressure lines, or explosion in vessels or pipe lines or catastrophic failure of tanks.

Locations and types of emergency• Ammonia Plant Fire, Explosion, Toxic Release• Urea & Granulation Plant Toxic Release, Fire, Explosion• Steam & Power Generation Fire & Explosion• Off Sites Utilities Toxic Release (Ammonia)• Product Handling Jetty Toxic Release Fire & Oil Spill• Response To Emergency

To locate the emergency situation in the plant, automatic Fire & GasDetection System has been installed. The fire and gas detection system (FGS) is intended to make an early detection of a fire situation and gas release (toxic and flammable) to provide a warning or alarm of the situation in order to allow check actions, either manual or automatic, to minimize the probability of degeneration of a dangerous situation.

The FGS is an integrated set of FGS subsystems. Each plant building constitute a subsystem with its own local fire and gas panel and display, located inside the building, to handle local detectors and alarms, detectors and alarms relevant to a defined process area, to report individual or cumulative alarms to the central fire and gas panel in Central Control Room and to a Mimic panel in the Fire Station and security main gate house.

Manual Call Points, Public address system, Intercom and wireless Systems are provided in the plant for fast communication with Emergency Control Center and Fire Station Control Room. On receipt of an alarm or fire/ gas leak message in Emergency Control Room, fire tender along with crew takes turnout and proceeds towards the scene of incident. The plant shift manager takes charge of the incident and acts as the Incident Controller and Fire crew in charge takes the command to control fire / emergency till the arrival of senior officers. Plant personnel are trained to work along side fire servicesand together provide a useful combination of skill and knowledge. If situation demands outside assistance, then ROP civil defense fire service are called under mutual aid scheme and emergency siren is blown as per the established siren tones.


Emergency siren code:

FIRE /GAS LEAK - Wailing sound for two minutesALL CLEAR - Continuous sound for two minutesTESTING - Continuous sound for 15 seconds

ON HEARING EMERGENCY SIREN• Key / Essential Personnel shall report to respective satellite room / EmergencyControl Room. - CCR• Non-essential personnel shall report to their shit supervisor and follow theinstruction for safe route of evacuation.• Note wind direction by checking windsock. Leave affected area immediately,moving crosswinds and upwind, never move downwind unless specific indicationis given by the site supervision.• Do not run, except in life threatening conditions.

RED SIREN: Fire Alarm• BLUE SIREN : Hot gas or Flue gas Alarm• YELLOW SIREN : Toxic gas Alarm


Instrumentation Department

Introduction to PLCS• Less wiring.• Wiring between devices and relay contacts are done in the PLC program.• Easier and faster to make changes.• Trouble shooting aids make programming easier and reduce downtime.• Reliable components make these likely to operate for years before failure.

PLC Origin

• - Developed to replace relays in the late 1960s• - Costs dropped and became popular by 1980s• - Now used in many industrial designs

Historical BackgroundThe Hydrometric Division of the General Motors Corporation specified the design criteria for the first programmable controller in 1968

Their primary goal To eliminate the high costs associated with inflexible, relay-controlled systems.

• The controller had to be designed in modular form, so that sub-assemblies could be removed easily for replacement or repair.

• The control system needed the capability to pass data collection to a central system. • The system had to be reusable.• The method used to program the controller had to be simple, so that it could be easily

understood by plant personnel.

Programmable Controller Development1968 Programmable concept developed1969 Hardware CPU controller, with logic instructions,

1K of memory and 128 I/O points 1974 Use of several (multi) processors within a PLC - timers and counters; arithmetic operations; 12 K of memory and 1024 I/O points1976 Remote input/output systems introduced1977 Microprocessors - based PLC introduced1980 Intelligent I/O modules developed

Enhanced communications facilitiesEnhanced software features (e.g. documentation)Use of personal microcomputers as programming aids

1983 Low - cost small PLC’s introduced1985 on Networking of all levels of PLC, computer and machine using SCADA software.


Programmable Logic Controllers(Definition according to NEMA standard ICS3-1978)A digitally operating electronic apparatus which uses a programming memory for the internal storage of instructions for implementing specific functions such as logic, sequencing, timing, counting and arithmetic to control through digital or analog modules, various types of machines or process.

Leading Brands Of PLCAMERICAN 1. Allen Bradley

2. Gould Modicon3. Texas Instruments 4. General Electric5. Westinghouse6. Cutter Hammer7. Square D

EUROPEAN 1. Siemens2. Klockner & Mouller3. Festo 4. Telemechanique

JAPANESE 1. Toshiba2. Omron3. Fanuc4. Mitsubishi

Areas of Application Manufacturing / Machining Food / Beverage Metals Power Mining Petrochemical / Chemical

PLC Size1. SMALL - it covers units with up to 128 I/O’s and memories up to 2 Kbytes.

- these PLC’s are capable of providing simple to advance levels or machine controls.2. MEDIUM - have up to 2048 I/O’s and memories up 32 Kbytes.3. LARGE - the most sophisticated units of the PLC family. They

have up to 8192 I/O’s and memories up to 750 Kbytes. - can control individual production processes or entire plant.


A

B

C

FS

MOTOR

TIMER

FLOAT SWITCH

SOLENOIDS

SOLENOID

1 -MINUTE

Tank Used to Mix Two Liquids

A tank is used to mix two liquids. The control circuit operates as follows:

1. When the start button is pressed, solenoids A and B energize. This permits the two liquids to begin filling the tank. 2. When the tank is filled, the float switch trips. This de-energizes solenoids A and B and starts the motor used to mix the liquids together. 3. The motor is permitted to run for one minute. After one minute has elapsed, the motor turns off and solenoid C energizes to drain the tank. 4. When the tank is empty, the float switch de-energizes solenoid C.5. A stop button can be used to stop the process at any point. 6. If the motor becomes overloaded, the action of the entire circuit will stop. 7. Once the circuit has been energized it will continue to operate until it is manually stopped.


PROCESSOR

POWERSUPPLY

I MN O P D U UT L E

O M U OT DP UU LT E

PROGRAMMING DEVICE

From SENSORS

Pushbuttons,contacts,

limit switches,etc.

ToOUTPUT

Solenoids, contactors,

alarmsetc.

Major Components of a Common PLCPOWER SUPPLY Provides the voltage needed to run the primary PLC components

I/O MODULES Provides signal conversion and isolation between the internal logic- level signals inside the PLC and the field’s high level signal.

PROCESSOR Provides intelligence to command and govern the activities of the entire PLC systems.

PROGRAMMING DEVICE used to enter the desired program that will determine the sequence of operation and control of process equipment or driven machine.

Also known as: Industrial Terminal ( Allen Bradley ) Program Development Terminal ( General Electric ) Programming Panel ( Gould Modicon ) Programmer ( Square D ) Program Loader ( Idec-Izumi )

Types: Hand held unit with LED / LCD display Desktop type with a CRT display Compatible computer terminal


OPTO-ISOLATO

R

IS NEEDED TO: Prevent voltage transients from damaging the processor.Helps reduce the effects of electrical noise

CurrentLimitingResistor

FROM INPUTDEVICE

USE TO DROP THE VOLTAGE TO LOGIC LEVEL

Buffer, Filter, hysteresis Circuits

TOPROCESSOR

I/O Module• The I/O interface section of a PLC connects it to external field devices. • The main purpose of the I/O interface is to condition the various signals received from or

sent to the external input and output devices. • Input modules converts signals from discrete or analog input devices to logic levels

acceptable to PLC’s processor. • Output modules converts signal from the processor to levels capable of driving the

connected discrete or analog output devices.

DC INPUT MODULE


OPTO-ISOLATO

R

IS NEEDED TO: Prevent voltage transients from damaging the processor.Helps reduce the effects of electrical noise

FROM PROCESSOR

TTLCircuits

AmplifierRELAYTRIACX’SISTOR

TOOUTPUTDEVICE

DC / AC OUTPUT MODULE


I/O Circuits

DIFFERENT TYPES OF I/O CIRCUITS

1. Pilot Duty OutputsOutputs of this type typically are used to drive high-current electromagnetic loads such as solenoids, relays, valves, and motor starters. These loads are highly inductive and exhibit a large inrush current. Pilot duty outputs should be capable of withstanding an inrush current of 10 times the rated load for a short period of time without failure.

2. General - Purpose OutputsThese are usually low- voltage and low-current and are used to drive indicating lights and other non-inductive loads. Noise suppression may or may not be included on this types of modules.

3. Discrete InputsCircuits of this type are used to sense the status of limit switches, push buttons, and other discrete sensors. Noise suppression is of great importance in preventing false indication of inputs turning on or off because of noise.

4. Analog I/OCircuits of this type sense or drive analog signals. Analog inputs come from devices, such as thermocouples, strain gages, or pressure sensors, that provide a signal voltage or current that is derived from the process variable. Standard Analog Input signals: 4-20mA; 0-10V


PLC

INPUTS

OUTPUTS

MOTOR

LAMPCONTACTOR

Analog outputs can be used to drive devices such as voltmeters, X-Y recorders, servomotor drives, and valves through the use of transducers. Standard Analog Output signals: 4-20mA; 0-5V; 0-10V

5. Special - Purpose I/OCircuits of this type are used to interface PLCs to very specific types of circuits such as servomotors, stepping motors PID (proportional plus integral plus derivative) loops, high-speed pulse counting, resolver and decoder inputs, multiplexed displays, and keyboards.

This module allows for limited access to timer and counter presets and other PLC variables without requiring a program loader.


L1 L2

P. B SWITCH

INPUT MODULE

WIRING DIAGRAM

LADDER PROGRAM

I:2

0

I= Input

Moduleslot # in rack

ModuleTerminal #

Allen-Bradley 1746-1A16

Address I:2.0/0

N.O

C

L2 L1

L1 L2

OUTPUT MODULEWIRING

MOTOR

CONTACTOR

O:4

0CONTACTOR

LADDER PROGRAM

L1 L2

FIELD WIRING

SOLENOIDVALVESLAMPBUZZER


Normally Open Pushbutton

Normally Closed Pushbutton

Normally Open switch

Normally Closed switch

Normally Open contact

Normally closed contact

Discrete InputA discrete input also referred as digital input is an input that is either ON or OFF is connected to the PLC digital input. In the ON condition it is referred to as logic 1 or a logic high and in the OFF condition maybe referred to as logic o or logic low.

ProcessorThe processor module contains the PLC’s microprocessor, its supporting circuitry, and its memory system.

The main function of the microprocessor is to analyze data coming from field sensors through input modules, make decisions based on the user’s defined control program and return signal back through output modules to the field devices. Field sensors: switches, flow, level, pressure, temp. transmitters, etc. Field output devices: motors, valves, solenoids, lamps, or audible devices.

The memory system in the processor module has two parts: a system memory and an application memory.


PHASE 2Program

Execution

PHASE 3Diagnostics/

Comm

PHASE 4Output

Scan

PHASE 1Read Inputs

Scan

Basic Function of a Typical PLC

Read all field input devices via the input interfaces, execute the user program stored in application memory, then, based on whatever control scheme has been programmed by the user, turn the field output devices on or off, or perform whatever control is necessary for the process application.

This process of sequentially reading the inputs, executing the program in memory, and updating the outputs is known as scanning.

While the PLC is running, the scanning process includes the following four phases, which are repeated continuously as individual cycles of operation:


PHASE 1 – Input Status scan

A PLC scan cycle begins with the CPU reading the status of its inputs.

PHASE 2– Logic Solve/Program Execution

The application program is executed using the status of the inputsPHASE 3– Logic Solve/Program Execution

Once the program is executed, the CPU performs diagnostics and communication tasks

PHASE 4 - Output Status Scan

An output status scan is then performed, whereby the stored output values are sent to actuators and other field output devices. The cycle ends by updating the outputs.

As soon as Phase 4 are completed, the entire cycle begins again with Phase 1 input scan.

The time it takes to implement a scan cycle is called SCAN TIME. The scan time composed of the program scan time, which is the time required for solving the control program, and the I/O update time, or time required to read inputs and update outputs. The program scan time generally depends on the amount of memory taken by the control program and type of instructions used in the program. The time to make a single scan can vary from 1 ms to 100 ms.

PLC Communications

Common Uses of PLC Communications Ports Changing resident PLC programs - uploading/downloading from a supervisory controller

(Laptop or desktop computer). Forcing I/O points and memory elements from a remote terminal. Linking a PLC into a control hierarchy containing several sizes of PLC and computer. Monitoring data and alarms, etc. via printers or Operator Interface Units (OIUs).

Serial CommunicationsPLC communications facilities normally provides serial transmission of information.

Common StandardsRS 232

Used in short-distance computer communications, with the majority of computer hardware and peripherals.

Has a maximum effective distance of approx. 30 m at 9600 baud.


Local Area Network (LAN)

Local Area Network provides a physical link between all devices plus providing overall data exchange management or protocol, ensuring that each device can “talk” to other machines and understand data received from them.

LANs provide the common, high-speed data communications bus which interconnects any or all devices within the local area.

LANs are commonly used in business applications to allow several users to share costly software packages and peripheral equipment such as printers and hard disk storage.

RS 422 / RS 485 Used for longer-distance links, often between several PCs in a distributed system. RS 485

can have a maximum distance of about 1000 meters.

SpecificationsSeveral factors are used for evaluating the quality and performance of programmable controllers when selecting a unit for a particular application. These are listed below.

NUMBER OF I /O PORTS

This specifies the number of I/O devices that can be connected to the controller. There should be sufficient I/O ports to meet present requirements with enough spares to provide for moderate future expansion.

Several factors are used for evaluating the quality and performance of programmable controllers when selecting a unit for a particular application. These are listed below.

NUMBER OF I /O PORTS

This specifies the number of I/O devices that can be connected to the controller. There should be sufficient I/O ports to meet present requirements with enough spares to provide for moderate future expansion.

Criteria• Number of logical inputs and outputs.• Memory• Number of special I/O modules• Scan Time• Communications• Software

A Detailed Design Process1. Understand the process2. Hardware/software selection3. Develop ladder logic4. Determine scan times and memory requirements


SpecificationsOUTPUT-PORT POWER RATINGSEach output port should be capable of supplying sufficient voltage and current to drive the output peripheral connected to it.

SCAN TIMEThis is the speed at which the controller executes the relay-ladder logic program. This variable is usually specified as the scan time per 1000 logic nodes and typically ranges from 1 to 200 milliseconds.

MEMORY CAPACITY

The amount of memory required for a particular application is related to the length of the program and the complexity of the control system. Simple applications having just a few relays do not require significant amount of memory. Program length tend to expand after the system have been used for a while. It is advantageous to a acquire a controller that has more memory than is presently needed.

PLC Status Indicators• Power On• Run Mode• Programming Mode• Fault

Examples of PLC Programming Software:1. Allen-Bradley – Rockwell Software RSLogix5002. Modicon - Modsoft3. Omron - Syswin4. GE-Fanuc Series 6 – LogicMaster65. Square D- PowerLogic6. Texas Instruments – Simatic6. Telemecanique – Modicon TSX Micro


Electrical Department

Electric power supply systemPower supply Need:-The electrical demand of the IFFCO complex is totally met by the on site generation;There is no public utility tie-in to the plant. Two Gas-turbine Generators provide thenecessary power for two Urea plants, two Ammonia plants and associated utilities, over awide range of operating and environmental conditions.

The gas turbine has a single shaft that cranks the generator via speed reducing gear toproduce 50Hz frequency electrical power.There is an 11kV HV bus which distributes the power to the following substations:-

1) S/S-1 Substation- a) 11kV distribution system. b) Steam generation. c) Instrument air. d) Inert gas.

2) S/S-2 Substation- a) Ammonia-1 (Unit 12). b) Ammonia-2 (Unit-22).

3) S/S-3 Substation- a) Urea-1 (Unit 11). b) Urea-2 (Unit 21). c) Granulation-1 (Unit 18). d) Granulation-2 (Unit 28).

4) S/S-4 Substation- a) Urea handling. b) Ammonia storage (Unit 39).

5) S/S-4.1 Substation- a) Jetty (Unit 39). b) Shipment (Unit 39).

6) S/S-5 Substation- a) Sea water intake unit (Unit 47). b) Electro chlorination unit. c) Effluent treatment.

7) S/S-6 Substation- a) Desalination unit (Unit 33). b) Fresh cooling water pump.


c) Boiler feed water preparation (Unit 31). d) Flare system. e) Workshop & Warehouse. f) Chemical & Outdoor storage. g) Natural Gas preparation.

8) S/S-6.1 Substation- a)Administration building. b)Control room. c)Canteen. d)Guard house. e)Gate house. f)Technical building.

In case of gas turbine failure, two emergency synchronous generators, driven by diesel engines shall constitute emergency source of electrical power to enable a safe shut down of the plant.

Energy Consumption:-Kalol unit has produced 544518 MT of urea and 344326 tonne of ammonia during the year 2005-2006 attaining a capacity utilisation of 100.00 % and 94.86 % respectively. The ever lowest specific energy consumption of 6.179 Gcal/MT and 8.967 Gcal/MT was achieved in the year 2005-06 for Urea and Ammonia production respectively.

Energy Saving Project:-IFFCO Kalol Ammonia plant is of early 70's Kellogg technology and has limitations in implementing new technologies. Space availability is another major problem. In spite of these constraints Kalol unit is continuously putting efforts to reduce specific energy consumption.

Energy Saving Project (ESP) is one such measure which aims in reducing specific energy consumption by 0.915 Gcal/t of ammonia at an estimated cost of Rs. 125.30 crores. ESP Phase-I was implemented and commissioned in May-June 2005. ESP Phase-II was implemented and commissioned in April-May 2006.

There is considerable reduction in Specific Energy Consumption of Ammonia and in turn, Urea as a result of implementation of schemes under ESP.The reduction trend in Specific Energy Consumption for the last three years is shown below.189 Energy cost in terms of percentage of manufacturing cost.

With continuous efforts in energy conservation, there is tremendous reduction in the energy cost and the same is illustrated below.Particulars 2003-04 2004-05 2005-06Energy cost (a) (Rs. Lakhs) 33915.65 36945.68 34964.78Manufacturing cost of Bagged Urea (b) (Rs. Lakhs) 39894.90 43689.14 46166.45(a)/(b)*100 85.01 84.56 75.74Energy Conservation Commitment, Policy and Organisational Set-up


Process Engg. Section, IFFCO Kalol carries out energy audit on regular basis. Plant operations are studied in detail to identify the areas for reducing specific energy consumption and minimizing losses.With this objective and based on detailed study of energy audits, Ammonia plant Energy Saving Project – Phase I andother energy saving schemes were successfully commissioned in June-2005.

Energy Policy:-At IFFCO Kalol, optimum utilisation of energy and the total energy management are the part of corporate mission and IFFCO is fully committed to reduce the specific energy consumption in the production of nitrogenous fertiliser through: Conducting in-house energy audit and monitoring the energy consumption norms. Carrying out various minor and major modifications. Adoption of technological advancement befitting to the old plant.190 Development of human resources. Creating safe, healthy and energy conscious working environment. Better housekeeping in the plant.

Organisation Chart of Process Engineering Section:-DIRECTOR (TECHNICAL)

|SR. EXECUTIVE DIRECTOR (TECH)

|GENERAL MANAGER

|CHIEF MANAGER (TECHNICAL)

|CHIEF MANAGER (PROCESS)

|SENIOR MANAGER

|MANAGERS

|DEPUTY MANAGER

|ASSISTANT ENGINEER


Energy Conservation Achievements:- Ever lowest yearly specific energy consumption of 8.967 Gcal/ t of Ammonia. Ever lowest yearly specific energy consumption of 6.179 Gcal/ t of Urea. Ever lowest monthly specific energy consumption of 5.952 Gcal/ t of Urea in February-06. Ever lowest monthly specific energy consumption of 8.728 Gcal/ t of Ammonia in February-06.

Important schemes implemented for performance improvement during the year 2005-06:-

1) Ammonia plantSeveral Schemes in phased manner under Energy Saving Project (ESP) were implemented in the year 2005 and 2006 to reduce specific energy consumption by 0.915 Gcal/t of ammonia at an estimated cost of Rs. 125.30 crores.ESP Phase-I was implemented and commissioned in May-June 2005.ESP Phase-II was implemented and commissioned in April-May 2006.

LTS Guard Bed and BFW Pre HeatersA new LTS guard reactor is installed at upstream of existing LT Shift Converter with the provision for replacing the catalyst during plant operation. In this way, it is possible to keep a low CO-slippage during the entire life of the LT shift converter catalyst.A guard bed with 11.6 m3 catalyst along with two BFW preheaters is installed. Furthermore the constraint for decreasing the steam/ carbon ratio during normal operation with old LTS catalyst is removed.

BASF AMDEA Two Stage CO2 Removal System192The conventional aMDEA CO2 removal system was consuming energy of 30,000 kcal/kg mole of CO2BASF a MDEA two stage CO2 removal system is installed to reduce energy consumption to about 10,000 kcal/kg mole of CO2The system includes a two stage absorption, low pressure and high pressure flashand stripping. The introduction of LP and HP flash vessels reduces the energy for regeneration of the solution and improves the quality of the CO2 product. New absorber has both lean and semi lean absorption.

Change over of ID Fan Drive Turbine from back pressure to condensing typeFor closing steam balance, back pressure ID fan turbine is modified to more efficient condensing one with a provision of atmospheric venting during plant startup. MP steam consumption reduces from 10.0 t/h to about 5.0 t/h and LP steam generationstopped.


2) Urea plant CO2 recovery with installation of ejector/separator system for CO2 centrifugal

compressorAbout 237 kg/h of CO2 from CO2 centrifugal compressor seal leak off gases of HP&LP cases is recovered by installing anejector/separator system. The CO2 recovery from vent gases is equivalent to additional urea production of 7 t/day. The net financial saving is Rs. 38 lakhs per annum.1932.2 Removal of last stage impeller and providing ARLON-1555 case wear rings for hydrolyser feed pump

As an energy saving measure, the original SS 316 wear ring of the hydrolyser feed pump is rep As an energy saving measure, the original SS 316 wear ring of the hydrolyser feed pump is replaced by Greene Tweede Make "ARLON-1555" ring. The pump clearance has reduced from about 0.8 mm to 0.5 mm and the leakages across the seal systemreduced resulting in increase of pump discharge pressure to 30.7 kg/cm2g as against the original normal pump discharge pressure of 24.0 kg/cm2g.With installation of ARLON-1555 wear ring and reducing one stage in hydrolyser feed pump, there is saving of 23.0 kWh power. Annual monetary saving will be Rs. 10 lakhs. In addition to above, ARLON-1555 case wear rings material imparts non-seizing and non-galling advantages, which will improve pump reliability.

Installation of smaller capacity low head surface condensate pump in urea plant52.5 m3/h capacity with 120 m head surface condensate pump was used to pump condensate from surface condenser to the utility deaerator. The actual required operating capacity is about 30 m3/h(design: 52.5 m3/h).30.0 m3/h normal capacity (Rated: 35.0 m3/h) with 85 m head surface condensate pump is installed in place of the higher capacity surface condensate pump. About 17 kW power is saved by installing smaller capacity and low head surface condensate pump. The cost of new pump installation is about Rs. 2,00,000/-(rupees two lakh only). The monetary saving is Rs.7,30,000/-.per annum. The pay back period works out to be about three months.1942.4 Provision of bigger size second evaporator steam control valve to reduce pressure drop in steam system.

The 3" control valve with Cv of 70 was designed for normal flow of 4.5 t/h with pressure drop of 3.0 kg/cm2. During high prilling load operation, it is required to supply 9.0 ata steam to second evaporator more than 4.5 t/h. It was causing limitation and the control was getting almost full open to maintain second evaporator outlet temperature. To keep the control valve in some operating range for operational flexibility, it was required to increase the 9 ata steam drum pressure to about 10.5 kg/cm2g.Steam system pressure loss survey was carried out & appreciable pressure loss was found across thecontrol valve. As per the study, to keep control valve in operating range with lower delta P across the control valve, higher Cv of the control valve (= 170) was required. As an energy saving measure, bigger size control valve is installed in June-2005 at cost of Rs.2.25 lakhs. With implementation of the scheme,the pressure drop across control valve has reduced, control valve supply full flow at desired 9.0 ata steam


drum pressure i.e. at about 7.0 to 8.0 kg/cm2g instead of 10.5 and control valve remains in operating range instead of wide open at full prilling load.It is now possible to maintain 9.0 ata steam drum pressure at 7.0 to 8.0 kg/cm2g. Due to this, about 1.0 t/h more 9.0 ata steam is generated from flashing of 23 ata steam condensate. The monetary saving works out to Rs.40 lakhs/annum. The pay back period is less than a month.

Single urea solution pump operation by installing bigger size urea solution flow control valveDuring normal plant operation, with one urea solution pump in operation, urea solution flow control valve to first evaporator was remaining about full open. To meet the flow requirement, it was required to operate both the urea solution pumps in paralleloperation and about 12 kW additional power was consumed in pumping system.To reduce the pressure drop in the control valve, the scheme isimplemented as under.New 6" globe type control valve having CV:312, class 300 # RF is installed in place of existing control valve of CV:187.The cost of modifications was around Rs.6,70,000/- (rupees six lakhs seventy thousand only). With bigger195 size flow control valve, the flow control valve is remaining in operating range with one pump in operation.This has saved about 11.7 kWh of electric power equivalent to annual monetary saving of about Rs.5.09 lakhs. The pay back period is about of one and half year.

*CONCLUDED*


iffco training report

Documents

lp flash vessel

moderate future expansion

local area network

hp flash vessel

annual monetary saving

syn gas compressor

prevent voltage transients

pay back period