Seminar Report on Annealing and Pickling Multi Metals Ltd, Kota

DEPARTMENT

OF

ELECTRONICS AND COMMUNICATION ENGINEERING

CERTIFICATE

This is to certify that a seminar report on summer training taken at

MULTIMETALS LTD. KOTA PLANT is submitted by VISHESH VIJAY,

student of 4th year (VII semester) in Electronics and Communication

Engineering of Rajasthan Technical University, Kota during the academic year

2011-2012. The report has been found satisfactory and is approved for

submission.

(Mr. PRANAY SHARMA) (Mr. RISHABH SHARMA)

Seminar Coordinator Seminar Coordinator

Asst. prof.EC Asst. prof.EC

1

ACKNOWLDEGMENT

We cannot achieve anything worthwhile in the field of technical education unless or until

the theoretical education acquired in the classroom is effectively wedded to the practical

approach that is taking place in the modern industries and the research institutes. It gives me

profound pleasure to have an opportunity to acknowledge and to express gratitude to those

who were associated with my training at MULTIMETALS LIMITED.

It is a matter of great privilege for me to present this report as a consequence of my

30 days Industrial Training, on the basis of practical knowledge gained by me during this

practical training at MULTIMETALS LTD. KOTA PLANT (RAJASTHAN) during session

2011-2012.

I am highly grateful to all Engineering departments and Engineers for their ample

guidance during my training period. I attribute heartiest thanks to following

officers/instructors at MULTIMETALS for their positive cooperation in learning during full

period of training.

1. Mr. Ajay sharma (Training Officer)

2. Mr. Ankit Vijay

I also owe a great deal to all other vocational trainees & persons who directly or

indirectly were a source of constant help & suggestions for me.

(VISHESH VIJAY)

2

PAGE INDEX

TOPIC PAGE NO

ABSTRACT 1

1. INTRODUCTION 2

1.1 About Multimetals Ltd. 3

2. GENERAL DESCRIPTION 5

2.1 Line Specifications 6

2.2 Line Equipments 7

3. ENTRY EQUIPMENTS 8

4. CRFH COIL 9

5. WELDING 10

6. DEGREASING 12

7. ANNEALING 14

8. FURNACE SECTION 16

9. COOLING SECTION 19

10. PICKING 21

11. SKIN PASS MILL 22

12. TENSION LEVELLER 24

13. EXIT EQUIPMENTS 26

14. ELECTRONICS INSTRUMENTS 27

CONCLUSION 37

BIBLIOGRAPHY 38

APPENDIXES

3

FIGURE INDEX

FIGURE PAGE NO

1.1 Site view of Multimetals plant 4

2.1 Block diagram of process 5

2.2 Line equipment 7

3.1 Enter equipment 8

5.1 Welding section 11

6.1 Degreasing layer 12

6.2 Degreasing section 13

7.1 Annealing process 15

9.1 Jet cooling section 20

10.1 Coil after pickling 21

11.1 Skin pass mill 23

12.1 Tension leveller machine 25

12.2 Modulation of tension leveller 25

14.1 DSC 28

14.2 PLC 31

14.3 Pressure gauge 33

14.4 Thermocouple 34

14.5 SCADA 36

4

ABSTRACT

According to the rules of Rajasthan Technical University, I have undergone my 30 days

Practical In plant Training at MULTIMETALS LTD. KOTA PLANT which is incorporated

in the syllabus for 4 year B.Tech. Course. The training report hereby submitted outlines the

course of work during my training in an oriented manner over a period of 30 days for

Electronics and Communication branch.

MULTIMETALS is ISO 9001:2008 certified Company. Adequate diagrams and

layouts have been provided for a more descriptive outlook and clarity of understanding.

In all, I have tried my best to present this report in a very precise and profitable

manner. Engineering students gain theoretical knowledge only through books, which in not

sufficient for absolute mastery in our field.

Thus, I made a sincere attempt to bring about the details which I experienced during

my training at “MULTIMETALS LTD. KOTA PLANT” from 10 JUNE TO 10 JULY 2011

through this report. I have tried my best to reproduce the facts & findings of the training

site.

5

CHAPTER-1

INTRODUCTION

About Multimetals Ltd.:-

Multimetals was founded in 1962 as a joint venture with Revere Copper and Brass Inc.,

USA. Today, we are premier manufacturers of seamless extruded copper, copper alloy

products including 90/10, 95/5, & 70/30 Cupro Nickel, Cunifer, Aluminium Brass,

Admiralty Brass, 70/30 Brass, 63/37 Brass, Naval Brass confirming to various international

standards. With our wide product range we cater to numerous industries like Air-

conditioning, Refrigeration, Heat exchangers, Nuclear and Thermal Power Plants, Ship

Building and Repairs, Petroleum refineries, Sugar Plants, Defense establishments i.e. Naval

Warships etc.

We have a technical collaboration with M/s Hitachi Cable Ltd., Japan, one of the

world leaders in Air Conditioning and Refrigeration Copper tube technology. 

The distinguishing factor about us is the quality of our products owing to which we

have won 13 Export Excellence awards since 1993-94. Multimetals is an ISO 9001:2008

certified company with its works approved from Lloyds Register. We possess PED

Certification and self-certification AD 2000 Merkblatt W6/2 from TUV Nord.

Apart from the Standard products, we have also started manufacturing other copper

based alloy semis in the form of hollows, sections, profiles and rods as per customers’

requirements, custom made as per the chemical, mechanical, metallurgical and physical

properties provided by the customer. We also offer PVC Coated Tubes and high

performance copper alloy wires, adding to our product range.

6

FIGURE 1.1- “MULTIMETALS LTD. KOTA PLANT”

7

CHAPTER-2

GENERAL DESCRIPTION

Uncoiling of CRFH Coil at uncoiler

Entry looper

FIGURE 2.1- BLOCK DIAGRAM OF PROCESS

8

Welding Degreasing

Annealing in furnance Cooling section

Pickling Exit looper Skin pass

Tension leveler Creep looper Recoiling of coil

LINE SPECIFICATION:-

Material to be Processed AISI 200,300, 400

Strip Thickness 0.3 mm – 3 mm

Strip Width 600mm – 1300 mm

Coil ID; (In & Out) 610 mm

Coil OD; (In & Out) 1800 mm (Max.)

Coil Weight 28 MT (Max.)

Hand of Line Right to Left

Product Mix AISI 200 – 60%,

AISI 300-30%, AISI 400-10%

Total length of line 320 meters

Height of equipment from 10.36 meters (app.)

+ 0 mill floors level

Depth of cellar from 5 m (exit lopper) (app.)

+ 0 mill floors level 7.5 m (sump pit) (app.)

Crane hook height 10.935 m

Line Consists Of:-

Entry Equipments with Looper

Welding machine from Guild,USA

Degreasing Unit

Annealing furnace

Pickling section

9

Skin pass mill with Creep looper

On-line Tension leveller and provision for side trimmer.

Exit equipments with looper

All Auxiliaries which includes Acid Storage, ETP, WT,

DM water plant Etc.

FIGURE 2.2-LINE SPECIFICATION

10

CHAPTER-3

ENTRY EQUIPMENT

2 Uncoiler with CPC unit

Paper winder with tension feedback unit.

Pinchrolls, 5 roll flatteners, Up cut shears, belt conveyors.

Flat leader end handling system by vacuum stacker; Bottom side shift able

Bridles;deflector,steering rolls;PU coated roll dia 1000 mmx1600 mm

Automatic seam welding machine from Guild USA; Welding time #4 min..

Coil car, coil centering system

FIGURE 3.1-ENTRY EQUIPMENT

11

CHAPTER-4

COLD ROLLED FULL HARD (CRFH)

Advantages:

Close Dimensional Tolerances

Excellent surface finish

Controlled mechanical & physical properties as per customer requirements

Excellent Testing Facilities

CRFH Specifications:

Thickness 0.30 mm – 5.5 mm

Width 6 mm – 1000 mm

Length(For Sheets) up to 7000 mm

Temper 1/8 Hard , 1/4 Hard, 1/2 Hard,

Full

Edge Mill Edge/ Slit Edge

Thickness Tolerance +/- 0.02 mm

Width Tolerance As per Specification

Coil Weight 0.250 MT – 10 MT

Coil ID 400 - 500 mm

Coil OD Up to 1300 mm

Length Tolerance(For Sheets) - 0 mm/+5 mm

12

CHAPTER-5

WELDING

Welding is a fabrication or sculptural process that joins materials, usually metals or

thermoplastics, by causing coalescence. This is often done by melting the workpieces and

adding a filler material to form a pool of molten material (the weld pool) that cools to

become a strong joint, with pressure sometimes used in conjunction with heat, or by itself,

to produce the weld. This is in contrast with soldering and brazing, which involve melting a

lower-melting-point material between the workpieces to form a bond between them, without

melting the workpieces.

Many different energy sources can be used for welding, including a gas flame, an

electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial

process, welding may be performed in many different environments, including open air,

under water and in outer space. Welding is a potentially hazardous undertaking and

precautions are required to avoid burns, electric shock, vision damage, inhalation of

poisonous gases and fumes, and exposure to intense ultraviolet radiation.

SEAM WELDING:-

Resistance seam welding is a process that produces a weld at the faying surfaces of

two similar metals. The seam may be a butt joint or an overlap joint and is usually an

automated process. It differs from butt welding in that butt welding typically welds the

entire joint at once and seam welding forms the weld progressively, starting at one end.

Like spot welding, seam welding relies on two electrodes, usually made from copper, to

apply pressure and current. The electrodes are disc shaped and rotate as the material passes

between them. This allows the electrodes to stay in constant contact with the

material to make long continuous welds. The electrodes may also move or

assist the movement of the material.

13

WELDING SECTION

Type -Guild Model QMM 125-54, Quick lap Seam Welder

Material 200,300,400 CRSS

Max. Strip Width 1300mm

Min. Strip Width 600 mm

Max. Strip Thickness 3.0mm

Min. Strip Thickness 0.3mm

Electrics 415/3/50

Weld Process Continuous Seam

FIGURE 5.1- WELDING MACHINE

14

CHAPTER-6

DEGREASING

Degreasing is a process that removes oils, grease, and solid dirt particles from metal

surfaces. Degreasing prepares a material for finishing applications such as primers, paints,

or bonds.

Parts cleaning is essential to many industrial processes, as a prelude to surface

finishing or to protect sensitive components. Electroplating is particularly sensitive to part

cleanliness, since molecular layers of oil can prevent adhesion of the coating. ASTM B322

is a standard guide for cleaning metals prior to electroplating. Cleaning processes include

solvent cleaning, hot alkaline detergent cleaning, electrocleaning, and.Hydrophobic

contaminants such as oils cause the water to bead and break up, allowing the water to drain

rapidly. Perfectly clean metal surfaces are hydrophilic and will retain an unbroken sheet of

water that does not bead up or drain off. ASTM F22 describes a version of this test. This

test does not detect hydrophilic contaminants, but the electroplating process can displace

these easily since the solutions are water-based. Surfactants such as soap reduce the

sensitivity

.

FIGURE 6.1-DEGREASING LAYER

15

degreasing section:-

(i) First degreasing stage - Spray degreasing machine

(ii) Second degreasing stage - Chemical scrub brush

(iii) Rinsing section - 3 –Stage cascade rinsing

(iv) Length of degreasing section – 18.15 meters (approx)

FIGURE 6.2-DEGREASING SECTION

16

CHAPTER-7

ANNEALING

Annealing, in metallurgy and materials science, is a heat treatment wherein a material is

altered, causing changes in its properties such as strength and hardness. It is a process that

produces conditions by heating to above the recrystallization temperature, maintaining a

suitable temperature, and then cooling. Annealing is used to induce ductility, soften

material, relieve internal stresses, refine the structure by making it homogeneous, and

improve cold working properties.

In the cases of copper, steel, silver, and brass, this process is performed by

substantially heating the material (generally until glowing) for a while and allowing it to

cool. Unlike ferrous metals—which must be cooled slowly to anneal—copper, silver and

brass can be cooled slowly in air or quickly by quenching in water. In this fashion the metal

is softened and prepared for further work such as shaping, stamping, or forming.

Annealing occurs by the diffusion of atoms within a solid material, so that the

material progresses towards its equilibrium state. Heat is needed to increase the rate of

diffusion by providing the energy needed to break bonds. The movement of atoms has the

effect of redistributing and destroying the dislocations in metals and (to a lesser extent) in

ceramics. This alteration in dislocations allows metals to deform more easily, so increases

their ductility.

The relief of internal stresses is a thermodynamically spontaneous process; however,

at room temperatures, it is a very slow process. The high temperatures at which the

annealing process occurs serve to accelerate this process.

17

ANNEALING PROCESS

Process annealing, also called "intermediate annealing", "subcritical annealing", or "in-

process annealing", is a heat treatment cycle that restores some of the ductility to a work

piece allowing it be worked further without breaking. Ductility is important in shaping and

creating a more refined piece of work through processes such as rolling, drawing, forging,

spinning, extruding and heading. The piece is heated to a temperature typically below the

austenizing temperature, and held there long enough to relieve stresses in the metal. The

piece is finally cooled slowly to room temperature. It is then ready again for additional cold

working. This can also be used to ensure there is reduced risk of distortion of the work piece

during machining, welding, or further heat treatment cycles.

The temperature range for process annealing ranges from 260 °C(500 °F) to 760

°C(1400 °F), depending on the alloy in question.

FIGURE 7.1-ANNEALING PROCESS

18

CHAPTER-8

FURNACE SECTION

ANNEALING FURNACE:-

SCOPE OF SUPPLY:-

ANDRITZ-THERMTEC offers annealing furnace equipment for a new APL for cold-rolled stainless steel strip.The furnace equipment will comprise following:

A - Furnace heating and cooling sections and auxiliary equipment, consisting of:-

Four (4) furnace chambers, heated by gas-fired, hot-air burners, as follows:

1st chamber, comprising an unfired preheating section

2nd chamber, unfired section plus 1 fired zone.

3rd chamber, 2 fired zones.

4th chamber, 3 fired zones

Heat recovery system with flue gas recuperator, including flue gas ducting, ex-

hauster fan and stack.

Combustion system, incl. main fuel gas station and pressure safety system, combus-

tion air fan and hot-air distribution and flow control system.

Ten (10) air jet-cooling chambers, including air supply fans and interconnecting

ductwork. The 2nd and 9th chamber will be fitted with water-mist spray-headers, for

accelerated cooling.

Three (3) air knives incl. fans; located at entry of 1st chamber, entry of 2nd chamber

and exit of 2nd chamber.

Exhaust system for waste cooling air, including exhauster fans and stack.

Strip supporting equipment, comprising ceramic fiber lined rolls and carousel type

furnace roll stands, including a transferable motorized carriage (1), for roll removal

in the heating and cooling sections.

Skid-mounted closed recirculation type cooling water system for furnace rolls.

Strip retraction cooler, ahead of furnace entry end.

Exit table with threading winch at exit end of the equipment.

Platforms, walkways, ladders and stairs, for access to the equipments.

19

Strip threading mechanism.

Process control system in pre-wired cabinets, incl. customized software for furnace

process control (recipe model control) and visualization.

Components for piping systems for combustion air, fuel gas, cooling water,

compressed air and impulse lines; incl. valves, expansion bellows, flexibles, packing

and sealing materials, as required.

Special cabling materials (standard cabling by others).

Special tools

B - Engineering and documentation, including:

Drawings and specifications for equipment components.

Drawings and specifications for components to be manufactured / supplied by the

Buyer or others.

Operating- and maintenance manuals.

Software documentation of process control.

C - Supervision services

Supervision for site installation.

Supervision for commissioning.

PRINCIPAL DIMENSIONS:-

20

The furnace equipment will have following approximate principal dimensions:-

Overall length, incl. strip retraction cool and exit table : 140,000 mm

Overall height of furnace equipment above support floor : 6,500 mm

Height of strip passline above support floor : 2,500 mm

Length of unfired preheat section : 21,000 mm

Total length of heating section : 73,900 mm

Length of cooling section : 52,500 mm

Inside width of heating chamber : 2,400 mm

Inside height of DGF heating chamber : 2,850 mm

Roll span heating section (typical) : 18,700 mm

Roll span cooling section (typical) : 5.200 mm

Discharge height of stacks above ground floor level : 23,000 mm

Diameter of waste combustion gas stack (approx.) : 1,200 mm

Diameter of waste cooling air stack (approx.) : 3,500 mm

GENERAL ARRANGEMENT OF FURNACE EQUIPMENT

It is understood that the furnace equipment will be located on a concrete support floor at

+4,500 mm elevation. This floor shall extend to the outer wall of the building to locate

various auxiliary systems, such as hot-air ducting, and fan equipment for the heating and

cooling sections. The flue gas recuperator and exhaust fan will be located in a pit.

Floor loads will typically be approx.:-

Furnace section 80 kN/m²

Cooling section 40 kN/m²

Recuperator and hot-air ducting, alongside furnace 50 kN/m²

Fan equipment, alongside cooling section 20 kN/m²

CHAPTER-9

COOLING

21

The strip will be cooled in 10 jet-cooling chambers. The method of strip cooling may be

adjusted for the various material grades and processing requirements by random selection of

the following cooling means or combination thereof.

High-convection jet-cooling with ambient air, in 10 air cooling chambers.

Additional accelerated cooling in the 2nd and 9th chamber by water-mist sprays

Separate adjustment of air flow from top and bottom plenums, to allow for

adjustment for various strip thickness and shape.

In the air jet-cooling chambers air will be supplied by centrifugal fans and blown

onto the strip surface through a number of plenum ducts, located above and below strip

passline, to provide uniform high convection air cooling.

The cooling rate in the JC chambers 1-4 can be controlled by speed control of the

jet-cool fan motors. The adjustment of the air flow in the other chambers is by motorized

inlet vane dampers on the fans.

All plenums and tubes facing the strip will be of stainless steel construction.

Strip support rolls / Roll carousels:-

The strip will be supported on rolls throughout the heating and cooling sections, as

follows:

1 fix mounted roll at the entrance of the 1st heating chamber.

4 carousel type roll stands for the heating sections, each with 2 rolls.

10 fix mounted rolls in the jet-cooling section, 1 after each jet-cool chamber.

Each furnace carousel will be fitted with two rolls (1 water-cooled bronze coated metallic

roll for heavy gauges and 1 fiber disc type roll for thin gauges).

22

FIGURE 9.1-JET COOLING SECTION

JET-COOLING SECTION:-

Each cooling chamber is enclosed in a casing of approx. 4 mm. steel plate, reinforced with

structural steel shapes. All air supply- and exhaust ducts and remaining construction will

also be of normal steel plate construction. All air plenum boxes will be constructed of

stainless steel plate, connecting to a common steel header.

Each chamber will be fitted with a hand operated flow damper to adjust the

distribution between top and bottom flow.

CHAPTER-10

23

PICKLING

Pickling is a metal surface treatment used to remove impurities, such as stains, inorganic

contaminants, rust or scale from ferrous metals, copper, and aluminium alloys. A solution

called pickle liquor, which contains strong acids, is used to remove the surface impurities. It

is commonly used to decaled or clean steel in various steelmaking processes.

The function of pickling is to dissolve/ remove/ peel off oxide layer on surface of

strip. Such oxide layers are formed during hot rolling and in case of cold rolled strip during

annealing operation.

FIGURE 10.1- COIL AFTER PICKLING

CHAPTER-11

24

SKIN PASS MILE

Skin passing is done to:-

1. To improve strip shape

2. To impart the desired surface finish to steel from 2D to 2B

3. To produce desired mechanical properties.

4. To eliminate minor surface blemishes.

5. Masking of yield point

2 Hi Mill

Elongation 1.5%

Roll Cleaning system

Bottom Roll having Hydraulic Gap Control

Quick Roll Changing device;

Roll changing time ~ 8 minutes

Roll changing is possible during running

High Pressure Hydraulic system

2 High roll – 800mm (max.) /

750mm (min.) x 1500mm barrel length.

Roll force – Max. 10,000 KN

25

FIGURE 11.1- SKIN PASS MILL

26

CHAPTER-12

TENSION LEVELER

The purpose of tension leveling is to bring all the fibers in the metal to equal

length:-

To achieve Desired strip elongation(0-2%) and strip flatness

Tension leveler consists of Entry bridle, Tension leveler wet type process, and Exit

bridles.

Design One set of bending roll cartridge two sets of anti cross bow roll cartridge

Tension – 350 KN (max.)

Roll configuration.

Bending roll module: 6 – High

Anti cross bow roll module: 3 – High.

Bending: - work roll – 35mmØ x 1600mm

Intermediate roll - 50mmØ x 1600mm

Back up roll - 60mmØ x 130mm

Anti cross: - work roll – 150mmØ x 1600mm

Back up roll - 60mmØ x 130mm

27

FIGURE 12.1-TENSION LEVELLER

FIGURE 12.2- MODULATION OF TENSION LEVELLER

28

CHAPTER-13

EXIT EQUIPMENTS

1 Recoiler with EPC Unit

Paper unwinder with Tension feedback unit

Pinch Rolls, Up Cut Shears, Belt Conveyor.

Bridles, Deflector, Steering rolls; PU coated

Roll dia 1000 mm x 1600mm.

Coil car with a provision to travel in other bay

4 Strands Dolly Type Looper; Storage capacity 566 m.

On line Weighing, Manual Strapping

Hydraulics & Pneumatic Systems

29

CHAPTER-14

ELECTRONIC INSTRUMENTS

Distributed control system (DCS):

INSTALLED AT: Have almost the same work as PLC but is unable to handle

not as much input as that PLC

WORKING PRINCIPLE:

Distributed control systems (dcs) are dedicated systems used to control manufacturing

processes that are continuous or batch-oriented, such as oil refining, petrochemicals, central

station power generation, pharmaceuticals, food beverage manufacturing, cement

production, steelmaking, and papermaking. DCSs a connected to sensors and actuators and

use set point control to control the flow of material through the plant. The most common

example is a set point control loop consisting of a pressure sensor, controller, and control

valve.

Pressure or flow measurements are transmitted to the controller, usually through the

aid of a signal conditioning Input/ Output (I/O) device. When the measured variable reaches

a certain point, the controller instructs a valve or actuation device to open or close until the

fluidic flow process reaches the desired set point. Large oil refineries have many thousands

of I/O points and employ very large DCSs. Processes are not limited to fluidic flow through

pipes, however, and can also include things like paper machines and their associated

variable speed drives and motor control centres, cement kilns, mining operations, ore

processing facilities, and many others.

A typical DCS consists of functionally and/or geographically distributed digital

controllers capable of executing from 1 to 256 or more regulatory control loops in one

control box. The input/output devices (I/O) can be integral with the controller or locate

remotely via afield network. Today controllers have extensive computational capabilities

and, in addition to proportional, integral, and derivative (PID) control, can generally

perform logic and sequential control .DCSs may employ one or several workstations and

can be configured at the workstation or by an online personal computer. Local

30

communication is handled by a control network with transmission over twisted pair,

coaxial, or fibre optic cable.

FIGURE:-14.1 DCS

Programmable logic controller (PLC):

Simplification of engineering and precise control of manufacturing process can result in

significant cost savings. The most cost-effective way, which can pay big dividends in

the long run, is flexible automation; a planned approach towards integrated control

systems. It requires a conscious effort on the part of plant managers to identify areas

where automation can result in better deployment/utilization of human resources and

31

savings in man-hours, down time. Automation need not be high ended and too

sophisticated; it is the phased, step-by-step effort to automate, employing control

systems tailored to one’s specific requirements that achieves the most attractive results.

That is where Industrial electronics has been a breakthrough in the field of automation

and control techniques.

ROLE OF ELECTRONICS IN AUTOMATION

A constant demand for better and more efficient manufacturing and process machinery

has led to the requirement for higher quality and reliability in control techniques. With

the availability of intelligent, compact solid state electronic devices, it has been possible

to provide control systems that can reduce maintenance, down time and improve

productivity to a great extend. By installing efficient and user friendly industrial

electronics systems for manufacturing machinery or processors, one can obtain a

precise, reliable and prolific means for generating quality products.

Considering the varied demand and increasing competition, one has to provide for

flexible manufacturing process. One of the latest techniques in solid state controls that

offers flexible and efficient operation to the user is “PROGRAMMABLE

CONTROLLERS”. The basic idea behind these programmable controllers was to

provide means to eliminate high cost associated with inflexible, conventional relay

controlled systems.

Programmable controllers offer a system with computer flexibility:

1. Suited to withstand the industrial environment

2. Has simplicity of operation

3. Maintenance by plant technicians and

4. Reduce machine down time and provide expandability for future.

DEFINATION OF PLC

A Programmable controller is a solid state user programmable control system with

functions to control logic, sequencing, timing, arithmetic data manipulation and counting

capabilities. It can be viewed as an industrial computer that has a central processor unit,

memory, input output interface and a programming device. The central processing unit

32

provides the intelligence of the controller. It accepts data, status information from various

sensing devices like limit switches, proximity switches, executes the user control program

store in the memory and gives appropriate output commands to devices like solenoid valves,

switches etc.

Input output interface is the communication link between field devices and the

controllers; field devices are wired to the I/O interfaces. Through these interfaces the

processor can sense and measure physical quantities regarding a machine or process, such

as, proximity, position, motion, level, temperature, pressure, etc. Based on status sensed,

the CPU issues command to output devices such as valves, motors, alarms, etc.

Programmer unit provides the man machine interface. It is used to enter the

application program, which often uses a simple user-friendly logic.

BENEFITS OF PROGRAMMABLE CONTROLLERS

1. Programmable controllers are made of solid state components and hence provide

high reliability.

2. They are flexible and changes in sequence of operation can easily be

incorporated due to programmability. They may be modular in nature and thus

expandability and easy installation is possible.

3. Use of PLC results in appreciable savings in Hardware and wiring cost.

4. They are compact and occupy less space.

5. Eliminate hardware items like Timers, counters and Auxiliary relays. The

presence for timers and counters has easy accessibility.

6. PLC can control a variety of devices and eliminates the need for customized

controls.

7. Easy diagnostic facilities are provided as a part of the system. Diagnosis of the

external systems also becomes very simple. Thus easy service/maintenance.

8. Programming devices provide operator friendly interface with the machine.

Being an outcome of the latest art of electronics technology, Programmable

controllers provide higher level of performance with computers is possible.

Useful management data can be obtained and maintained.

9. It has total protections against obsolescence and has wide scope for upgradation.

33

INSTALLED AT: - Serve as the centre for monitoring ,controlling and measuring all the

parameters in control room. PLC in short act as the important computer to control the

process flow.

Figure-14.2 PLC

WORKING PRINCIPLE:-

A programmable logic controller (PLC) or programmable controller is a digital computer

used for automation of electromechanical processes, such as control of machinery on

factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many

industries and machines, such as packaging for multiple inputs and output arrangements,

extended temperature ranges and semiconductor machines, unlike general-purpose

computers, the PLC is designed immunity to electrical noise, and resistance to vibration and

impact. Programs control machine operation is typically stored in battery-backed or non-

volatile memory. A PLC is an example of a real time system since output results must be

produced in response to input conditions within a bounded time ,otherwise unintended

operation will result.

34

Transducers

1. Resistance Temperature Detector (RTD):

INSTALLED AT:

Installed in furnaces to measure, monitor and regulate the temperature.

WORKING PRINCIPLE:

It is a temperature sensor that exploits the predictable

Change in electrical resistance of some materials with changing temperature based on

positive temperature coefficient of resistance. As they are almost invariably made of

platinum, they are often called platinum resistance thermometers (PRTs). They are slowly

replacing the use of thermocouples in many industrial applications below 600C, due to

higher accuracy and repeatability.

2. Bourdon Gauge:

INSTALLED AT:

Installed measure pressure at sinter, zinc and lead circuit.

WORKING PRINCIPLE:

A Bourdon gauge uses a coiled tube, which as it expands due to pressure increase causes a

rotation of an arm connected to the tube. The pressure sensing element is coiled tube

connected to the chamber or pipe in which pressure is to be sensed. As the gauge pressure

increases the tube will tend to uncoil which is a reduced gauge pressure will cause the tube

to coil more tightly.

This motion transferred through a linkage to a gear train connected to an indicating needle.

35

3. Pressure Gauge:

INSTALLED AT: Installed measure pressure at sinter, zinc and lead circuit.

FIG:-14.3 PRESSURE GAUGE

WORKING PRINCIPLE: A vacuum gauge is used to measure the pressure in a vacuum

which is further divided into two sub categories high and low vacuum and sometimes ultra

high vacuum .The appreciable pressure range of many of the techniques used to measure

vacuum have an overlap. Hence by combining several different types of gauges, it is

possible to measure system pressure continuously from 10 mbar to very low value.

4. Thermocouple:

INSTALLED AT:

Many places to measure the temperature.

WORKING PRINCIPLE:

A thermocouple is a junction between two different metals that produces a voltage related

to a temperature difference. Thermocouples are a widely used type of temperature sensor

and can also be used to convert heat into electric power. The main limitation is accuracy;

System errors of less than one Kelvin (K) can be difficult to achieve. [Citation needed] Any

circuit made of dissimilar metals will produce a temperature-related difference of voltage.

Thermocouples for practical measurement of temperature are made of specific alloys, which

in combination have a predictable and repeatable relationship between temperature and

voltage. Different alloys are used for different temperature ranges, and to resist corrosion.

Where the measurement point is far from the measuring instrument, the intermediate

36

connection can be made by extension wires, which are less costly than the materials used to

make the sensor. Thermocouples are standardized against a reference temperature of 0

degrees Celsius; practical instruments use electronic methods of cold-junction

compensation to adjust for varying temperature at the instrument terminals. Electronic

instruments can also compensate for the varying characteristics of the thermocouple, and so

improve the precision and accuracy of measurements. Thermocouples are widely used in

science and industry; a few applications would include temperature measurement for kilns,

measurement of exhaust temperature of gas turbines or diesel engines, and many other

industrial processes.

FIGURE:-14.4 WORKING PRINCIPLE OF THERMOCOUPLE

37

SCADA:

INSTALLED AT: This act as the interface between measuring and controlling

the different parameters . In short SCADA is the language of PLC and DCS.

WORKING PRINCIPLE: 14

SCADA stands for Supervisory Control and Data Acquisition.

The term SCADA usually refers to centralized systems which monitor and control entire

sites, or complexes of systems spread out over large areas (anything between an industrial

plant and a country). Most control actions are performed automatically by remote terminal

units ("RTUs") or by programmable logic controllers ("PLCs"). Host control functions are

usually restricted to basic overriding or supervisory level intervention. For example, a PLC

may control the flow of cooling water through part of an industrial process, but the SCADA

system may allow operators to change the set points for the flow, and enable alarm

conditions, such as loss of low and high temperature, to be displayed and recorded. The

feedback control loop passes through the RTU or PLC, while the SCADA system monitors

the overall performance of the loop. Data acquisition begins at the RTU or PLC level and

includes meter readings and equipment status reports that are communicated to SCADA as

required. Data is then compiled and formatted in such a way that a control room operator

using the HMI can make supervisory decisions to adjust or override normal RTU (PLC)

controls. Data may also be fed to a Historian, often built on a commodity Database

Management System, to allow trending and other analytical auditing

38

FIGURE:-14.5 SCADA

SCADA systems typically implement a distributed database, commonly referred to as a tag

database, which contains data elements called tags or points. A point represents a single

input or output value monitored or controlled by the system. Points can be either "hard" or

"soft". A hard point represents an actual input or output within the system, while a soft point

results from logic and math operations applied to other points. (Most implementations

conceptually remove the distinction by making every property a "soft" point expression,

which may, in the simplest case, equal a single hard point.) Points are normally stored as

value-timestamp pairs: a value and the timestamp when it was recorded or calculated. A

series of value-timestamp pairs gives the history of that point. It's also common to store

additional metadata with tags, such as the path to a field device or PLC register, design time

comments,

39

CONCLUSION

In this orientation program that I underwent during our summer training session at

MULTIMETALS LTD. KOTA PLANT, I studied about various industrial process and

various instruments installed at the ANNEALING & PICKLING unit. These process were

of varying_fields like chemical, mechanical, electronic and civil. I also gained knowledge

of mining and metallurgical industries and their scenario in India. In my training program i

was able to learn the practical aspect of all the electrical instruments i have learnt so far

during the course of my study. I also learnt about the professional hierarchy of an industry,

about various departments that exists in an industrial firm like MULTIMETALS LTD.

Hence with this I would like to conclude that the duration of this training was a

knowledge gaining experience which would help me in the future.

40

BIBLIOGRAPHY

The followings books and websites were referred to during the making of the project report.

1. Manuals provided at MULTIMETALS.

2. http://www.multimetals.in

3. http://www.seminar projects.com

4. http://www.wikipedia.com

41