REPORT ONTRAININGATJ. K. LAKSHMI CEMENT , JAYKAYPURAMSubmittedIn partial fulfillmentFor the award of the Degree ofBachelor of TechnologyIn Department of Electronic Instrumentation& Control Engineering

SUBMITTED TO: SUBMITTED BY:

Priyank Soni (10EEAEI041)Department of Electronic Instrumentation & ControlEngineeringGOVT. ENGINEERING COLLEGE, AJMERAugust, 2013

ABSTRACTBlindness is more feared by the public than any other ailment. Artificial vision for the blind was once the stuff of science fiction. But now, a limited form of artificial vision is a reality .Now we are at the beginning of the end of blindness with this type of technology. In an effort to illuminate the perpetually dark world of the blind, researchers are turning to technology. They are investigating several electronic-based strategies designed to bypass various defects or missing links along the brain's image processing pathway and provide some form of artificial sight. This paper is about curing blindness. Linking electronics and biotechnology, the scientists has made the commitment to the development of technology that will provide or restore vision for the visually impaired around the world. This paper describes the development of artificial vision system, which cures blindness to some extent. This paper explains the process involved in it and explains the concepts of artificial silicon retina, cortical implants etc. The roadblocks that are created are also elucidated clearly. Finally the advancements made in this system and scope of this in the future is also presented clearly.

IIII

ACKNOWLEDGEMENTIt gives me immense pleasure in presenting my training report. I would like to take this opportunity to express my deepest gratitude to the people, who has contributed their valuable time for helping me to successfully present this seminar.

One of most important principles of the universe is each and every indivisual is unique and different and varies having his own identity and indivisuality. The same principle also applies to the organization. In addition these entities have their own set of values, norms, procedure, practices, which are to be followed in the day to day work life.

My training with J.K.Lakshmi cement Limited is truly a rewarding and knowledgable one. At the end it has served the purpose for which it has been designed by making me well acquainted with the practices, procedure, strategies and most importantaly POTENTIAL PEOPLE IN in the organization.

TABLE OF CONTENTSCHAPTER NO. TITLE PAGE NO.ABSTRUCT ACKNOWLEDGEMENTLIST OF FIGUREvi

1.INTRODUCTION 1.1 INTRODUCTION TO J.K. LAKSHMI CEMENT LTD.1.2 INTRODUCTION TO PLANT EFFICIENCY2.CEMENT DEFINITION AND MANUFACTURING PROCESS2.1 MINING2.2CRUSHING 2.3 RAW GRINDING 2.4 BLENDING SILO 2.5 COAL MILL 2.6 PYROPROCESSING 2.7 FINISH GRINDING 2.8 PACKING3.EQUIPMENTS USE IN CEMENT PLANT 3.1 CRUSHER3.2 AIR LIFT SYSTEM 3.3 BELT BUCKET ELEVATOR3.4 CHAIN BUCKET ELEVATORS3.5 ROTARY PACKER4. ROLE OF INSTRUMENTATION IN CEMENT PLANT 4.1 SAFTEY INSTRUMENTS 4.1.1 PULL CORD SWITCH 4.1.2 BELT SWAY SWITCH 4.1.3 BOOT LEVEL SWITCH 4.1.4 ZERO SPEED SWITCH 4.2 MEASURING INSTRUMENTS 4.2.1 THERMOCOUPLE 4.2.2 RTD 4.2.3 TECHOGENERATOR 4.2.4 CURRENT TRANSDUCER 4.2.5 KILOWATT TRANSDUCER 4.2.6 LEVEL MEASUREMENT 4.2.7 TRANSMITTERS 4.2.8 WEIGHING EQUIPMENTS5. CONTROL METHOD 5.1 DISTRIBUTED CONTROL SYSTEM 5.2 TDC 3000 CHARACTERISTICS

CONCLUSION31REFERENCES32

LIST OF FIGURE FIGURE NAME PAGE NO.

Figure 2.1 Crusher

Figure 2.2 Silo3

Figure 3.1 Bucket Elevator4

Figure 3.2 Rotary Packer 6

Figure 4.1 Pull Cord Switch6

Figure 4.2 Thermocouple7

Figure 4.3 RTD 8

Figure 4.4 Weigh Feeder12

1.INTRODUCTION 1.1 INTRODUCTION TO J .K. LAKSHMI CEMENT

The J.K. Lakshmi Cement Limited was initially incorporated as a Private Company in 1951; subsequently the company was converted into a Public Company on May 4, 1974.

J.K.. Lakshmi Cement Limited is a Member of J.K.Organisation. The plant located in the lower part of Rajasthan at Jaykaypuram on the border of Gujarat in District Sirohi a No Industry District of Rajasthan.

The first dry process Cement Plant of Company was set up in Jaykaypuram and commissioned in August, 1982, with original capacity of 0.5 Million Tone per annum which was enhanced in 1991 to 0.6 Million Tone per annum.

The Company had a Technical Collaboration with M/s. Blue Circle Industries PLC, UK for a period of 1983 to 1993 for full utilization of capacity, quality improvement and increased productivity.

Due to substantial improvement carried out by the company, the capacity of plant has been increased from 0.6 MTPA to 2.2 MTPA by way of putting of two more Clinkerisation units (Unit#2 Phase#1 & Phase#2) in 1995 and 1996 respectively. Initially these units had production capacity of 2500 TPD and 2800 TPD respectively which were further increased to 3100 TPD each in October 1998 and June 1999.At present by addition of Parallel preheater to Kiln No. 2 (Phase-I)Kiln No. 3 (Phase-2) the increased Production Capacity is 4200 TPD for Kiln-2 and 4500 TPD for Kiln-3.

Limestone is excavated from captive mines (Company owned and fully mechanized) located about 2 KM from factory and spread over 414 Hectares having sufficient resources of raw materials.

The Plant falls under the category of Large Scale Industry and has present turnover of about Crores.

The factory and township have been laid out a plan with a Community center, Metal roads, School, Market etc., Metallic roads are provided for transportation of raw materials, finished goods and other items, Company has also provided recreational facilities including TV Center & Disc Antenna.

Factory has a well-equipped workshop to meet its contingencies.

Plant is getting electric power from Jodhpur Vidyut Vitran Nigam and has a contract demand of 40 MW. To meet any emergency requirement of power, the factory has 5 DG Sets (4 MW x 2, 3.5 MW x 1, 6 MW x 2) with total generating capacity of 23.5 MW. Factory has installed own Captive Power Plant of 18x2 MW and have started its Unit-1 power generation from May-2007. Water is drawn from Dhanari Dam as well as bore wells within the factory premises and is sufficient for meeting plant requirement of 31 Million Cubic Feet per annum. A water treatment plant is in continuous operation to obtain required quality of water.

It has permanent workers of different categories besides casual workers. It is a continuous process plant and is working in three-shift basis.

The plant is well connected with Rain & Road. The plant is located on National Highway No.14 (Delhi-Ahmedabad). Banas Railway Station is about 2 KM from Factory. Railway siding, under company arrangement has been constructed, from Banas Railway Station for shipment of products.

The unit manufactures following grades of Cement in confirmatory with the standard specifications of Bureau of Indian Standards.

a.OPC Grade 33 as per IS 269-1989b.OPC Grade 43 as per IS 8112-1989c.OPC Grade 53 as per IS 12269-1987d.Portland Pozzolana Cement as per IS 1489-1991 (Part-II).

1.2.INTRODUCTION ABOUT PLANT EFFICIENCY

Plant: J.K. Lakshmi Cement Limited An ISO 9001-2000, ISO-14001-2004 andOHSAS-18001-1999 Amendment-1-2002company

Unit 1

Commissioned In Year: 1982 Capacity: 6 Lac Tons Per Annum

Unit 2

Commissioned In Year: 1995 Capacity: 8.25 Lac Tons Per Annum

Unit 3

Commissioned In Year: 1996Capacity: 9.25 Lac Tons Per AnnumTotal Capacity: 17.5 Lac Tons Per Annum

2.DEFINATION AND TYPES OF CEMENT

Cement can be defined as any substance which can join or unite two or more pieces of some other substance together to form a unit mass. Cement, as used in construction industries, is a fine powder which when mixed with water and allowed to set and harden can join different components or members together to give a mechanically strong structure. Thus, cement can be used as a bonding material for bricks or for bonding solid particles of different sizes to form a monolith. Construction of houses for shelter is one of the oldest industries in human civilization, and cement of one kind or the another has been used from the pre-historic times for construction purposes. Lime and /or lime mixed with clay matter, burnt or otherwise, has been used for bonding of bricks and stone masonry for at least a millennium, and various theories have been propounded from time to time to account for the setting and hardening properties of lime mortars. It was just a 150 years ago that Cement as we know it today was developed or invented.

The range of chemical composition of Portland Cement types is given:-

SiO219 to 25%

Al2O32 to 8%

Fe2O30.3 to 6%

CaO60 to 65%

Mgo1 to 60%

SO31 to 3%

Alkalies0.5 to 1.5%

PROCESS OF CEMENT MANUFACTURING

1. Mines(raw material/limestone) 2. Crushers3. Lime stone stacker and reclaimer 4.VRM5. Kiln, Coolers.6.Coal pile stock 7. Cement mills8.Packing section

CEMENT MANUFACTURING PROCESS

Preparation of Raw Materials

There are three distinct processes for manufacturing Portland cement: -

(a) Wet Process (30 to 40 % water)(b) Dry Process (3 to 4% water)(c) Semi-Dry Process (10to12%water)

THE PROCESS

2.1 MININGLimestone of our mine is cement grade limestone, which is having all necessary oxides sufficient to produce cement clinker. Limestone being the basic raw material is available in our mines in abundance. The stone is blasted by explosives loaded into dumpers with the help of Excavators and Shovels. The dumpers carry the limestone and dump into the hoppers of Crusher.

2.2 CRUSHING & STACKINGThis consists of hopper in which limestone is dumped. At the bottom of the hopper is a grizzly feeder, which feeds stone above 150mm size to the crusher. The crusher breaks the stone to less than 80mm size and delivers it to a belt conveyer, which takes the stone up to a BMA tower.

Fig 2.1 CrusherThe stone below 150mm in the hopper goes to the screen house where the fraction of stones greater than 80mm size are returned to the crusher and fraction of stone less than 20mm size is thrown away as reject.The BMA analyses the limestone foe chemical composition so as to facilitate selection of proper quality of limestone. The stone is then stacked in the stockpile so as to form a kidney shaped pile. The quality of limestone ranging in b/w 80 to 130 LSF (lime saturation factor) or 70 to 82% TC (total carbonate) of limestone content is accepted where as the limestone having less than 80%LSF will go to the low grade limestone pile which can be used for lowering the LSF if required. The screen house raises the limestone quality by sieving and thus high LSF130 and above is stocked in high-grade stockpile.2.3 RAW GRINDING The limestones is extracted from the pile by reclaimer and send to blended limestone hoppers, additives like high grade limestone, low grade limestone can be taken through a separate system of belts after their respective hoppers after Weighment.

These materials in the required proportion are extracted by weighing feeders and send to the vertical roller mills (VRM) where they are ground to a fine powder and the powder is collected in cyclone separators and the bag house. A system of air slides and screw conveyers take the raw meal to the bucket elevators, which put the material in the blending silo (CF silo). The particle size of fine powder is controlled with the help of seperator to maintain the residue percentage on 90-micron sieve the range of 183%.

2.4 BLENDING SILOThe blending silo is of continuous flow type, the extraction being done through ten air slides from the bottom. The method of extraction itself leads to proper blending of the meal before entering the load cell hopper.

Fig 2.2 SiloThe raw meals are extracted from the load cell hopper by air slides through a solid flow meter, which control the extraction rate as per our requirement. Therefore a system of air slides feed it into the belt elevators going to the top of the pre heater tower. The raw meal is transferred to storage silos for KILN NO.1.

2.5 COAL MILLSWe are having 2nos. coal mills i.e. Conventional Ball Mills to produce the desired fineness of Fine Coal.

2.6 PYROPROCESSINGThis is done in a four stage Preheater for KILN NO1 and six stage suspension preheater tower with separate line calciner for KILN NO. II & KILN NO. III. The material comes in contact of hot gas coming out of kiln and temperature of material goes on increasing from first stage to the calciner. Pyroprocessing is having certain distinguish advantages such as:

(a)The raw material is better Calcined in the calciner. (b)The cooler, which is a controlled low grate cooler, is more efficient than the conventional cooler thereby yielding better heat recovery.(c)Instead of conveying the clinker to stockpile it is conveyed to the clinker silos so that it is not affected by weather conditions and moreover it supplies the material for cement grinding in more homogenous manners. The variation in quality is minimum.

2.7 FINISH GRINDING

(A)For cement mill no. III, & I we are having closed circuit conventional ball mill.(B)For cement mill no. II, the clinker & gypsum are first fed to a roller press, which crushes the material in the form of cake, which are fed into ball mills. (C)The cement is conveyed by means of air slides and elevator.(D)The quality of cement grinding i.e. specific surface is maintained with the help of O-SEPA seperator speed as per the requirement of the cement produced.

2.8 PACKINGPackers are of electronic type so that consistent weight of cement fill bags are maintained within ranges of 50 to 50.5 kg/bag.

3.EQUIPMENTS USE IN CEMENT PLANT

3.1 CRUSHERS

Crushers are use to desizing of raw material.The raw material as received from the mines are in lump form and have to be crushed before fine grinding .The size of lumps would depend upon the raw material and the method of mining, so the size of the crushing equipment used would depend primarily upon the size of the lumps received .In the mordern cement factory, manufacturing 100 to 2000 tonnes of cement per day ,the limestone is mined by mechanical means and hence the size of indiviual pieces may be 1 meter or so . In smaller factories ,the mining of limestone may be manual and the size of individual pieces may be 200mm or so .Similarly, clay, shale, bauxite, laterite, sandstone, coal, gypsum etc may be received in sizes not larger than 300mm.Types of crushers1.EV crusher2. Compound crusher

Specification: - EV CRUSHER (1030) Make Fuller-FLS Size EV200*300 Capacity 1100TPH Feed size 1500mm(max) Product size 80 mm (97%) Rotor size 200 mm dia. & 300 mm longWeight 160 Tons

HAMMER CRUSHERImpact Hammer Crusher, Type EV 200*300 for crushing of limestone. The Hammer crusher is of single rotor type, with outlet grates and inlet roller, and is designed for larger size reduction in one stage The feed fall upon two slowly rotating shock-absorbing roller transporting the material to be crushed to the crusher properly. Part of the fines is separated off at this stage. In the crusher, the hammer break up the material and hurl it against the lining of the upper part of the crusher for further fragmentation. Final crushing takes place at the adjustable crushing plate and at the outlet grates.The rotor shaft runs in amply dimensioned spherical roller bearing in split bearing housing with oil bath lubrication and grease filled labyrinth seals. The bearing housing are placed on rigid bottom frame of cast steel, bolted together .The bottom frame is provided with large, hinged access doors and lined with wear resistant, bolted on lining plate, at areas exposed to wear from crushed material.

The heavy ,forged ,square ,rotor shaft is provided with cast steel hammer discs. The chrome alloy mananese steel hammer are suspended on through going hammer bolts of induction hardened chrome nickel steel ,supported in replaceable,hardened bushing of chrome nickel molybdenum steel placed in the hammer discs .The hammer bolt are locked into position by discs at either end of the rotor.The hammer are symmetrically shaped and can be turned so that the leading amnd trailing edges are reversed , thus prolonging the useful life orf the hammers.

Outlet grate assembly with study, replaceable, manganese steel grate bars, carried in strong cast cheeks .The position of the grate assembly is adjustable from outside the crusher casing to compensate for wear.Heavy cast steel adjustable breaker plate with bolted on manganese steel lining.The two cast steel inlet roller is placed on shaft with shock absorbing rubber blocks between roller and shafts. The shaft s rotate in grease lubricated spherical roller bearing in bearing housing with labyrinth seals, placed on the bottom frame.

The other one connected through an enclosed chain drive drives one of the rollers.Top casing made of rigid, large, welded up, section bolted together for easy dismantling, allowing removal and installation of rotor and inlet roller without dismantling the feeder for the crusher. However, the top casing does not have to be removed when replacing the hammer proper T casing is provided with bolted on lining plates of manganese steel and carbon steel, the latter for areas less exposed to wear.

A heavy, vertical chain curtain is suspended in the crusher inlet to prevent material from being hurdled back onto the feeder .The rotor shaft is provided with a flywheel placed on a flanged bushing, the latter keyed to the rotor shaft and with two shear pins between flywheel and bushing, cut off switch which stops the crusher, inlet roller and feeder motion in case the shear pins break and the fly wheel starts rotating on the bushing.Included is membrane coupling with torsion shaft between the drive flange of the flywheel and the slow speed shaft of separate gear unit for it. Included in the supply of the crusher is also over loaded protection equipment, which stops the feeder in front of the crusher and the inlet roller, in case of over load condition has been occurred.

3.2 AIR LIFT SYSTEMAir lift or pneumatic elevator is capable of conveying dry pulversied material through a vertical pipe to the discharge into receiver or bins at a substantially higher level.The cylindrical shaped feed bin has a fully aerated bottom to allow complete fluidisation of the material in the bin .The pressure head effect in the fluidised material acts to move the material towards the air nozzle. The material converging , with the primary air from the nozzle is conveyed upward through the air lift pipe .The pri mary air supply furnishes air to the airlift nozzle through a pipe manifold with check valve . The aeration air supply furnishes air to the bottom of the feed bin to fluidised the material in the bin . With separated source of air , the degree of fluidisation of the material can be finely tuned to obtain the ultimately material density and feed rate to the airlift pipe .The use of the separate air source for bin aeration prevents any possibility of material entering the plenum and blinding the media in case of power failure .

3.3 BELT BUCKET ELEVATORCotton fabric belts as traction element to be employed for biucket elevator of the self loading type which scooped up the material by the digging action of the bucket for the handling of light fine grained materials (below 60 mm particle size.

Fig 3.1 Bucket Elevator

The desire to achieve greater elevating heights and to operate at higher temperture led to the development of the belt incorporating polyster and steel cable reinforcing elements.This has resulted in general change in high capacity bucket elevator engineering .Whereas chain bucket elevator are normally built for elevating height not more than 50-60 m, with steel cable belts it is possible to attain height of upto 100m.

3.4 CHAIN BUCKET ELEVATORSThis is the only type of bucket elevator that can be used for the handling of materials.Beside bushed chains, round link chain are also used , their advantage being the smaller chain pitch giving quiter running on passing round the sprocker or chain wheel .For high capacity bucket elevator it is necessary to use suitably heat treated (quenched and tempered) steel chains of the round link type in order to keep the amount of wear at the points of articulation within acceptable limits.Another of this open type of chain, especialaly for the handling of dry material consisting of angular particles ,is that these will not attach themselves to the round articulation surfaces of the links and thus cause heavy wear.

3.5 ROTARY PACKER In contrast with the in line packer with its filling spouts mounted stationary side by side , required the machine operator to move from spout to spout , the spout , the rotary packer move one by one into position in front of the operator , who merely has to fit the valve sack s onto them as they successively pass him.

Fig 3.2 Rotary Packer

There are rotary packer with 6,8,12 and 14 spout s.Fig .show the weighing system conventionally used for rotary packers and show an electronics system.

4.ROLE OF INSTRUMENTATION IN CEMENT INDUSTRY.Instrumentation is used for safety of equipments, measurement of important parameters, and control of process parameter and quality control of the final products.

4.1 UNDER SAFETY INSTRUMENTS IN LAKSHMI CEMENT THERE ARE: -

1)Pull Cord Switch2)Belt Sway Switch3)Boot Level Switch4)Pressure Switch5)Zero Speed Sensor

4.1.1 PULL CORD SWITCH

Switches are attached to the belt at equal distances and these switches are joined by cords. If the material splits from belt the switch is triggered.

Fig 4.1 Pull Cord Switch

Also, in case of some accident the operator can pull the cord which triggers the switch and the belt is stopped. Used in belt conveyors, deep bucket conveyors.

4.1.2 BELT SWAY SWITCH

To prevent the excess swaying of belt on either side switches are attached, therefore, if the belt sways to the sides the switch is tripped which in turn stops the belt. Used in belt conveyors, deep bucket conveyors, bucket elevators.

4.1.3 ZERO SPEED SWITCH

The belt has a driver side which has a motor and a driven end to which a proximity is attached It has four flanges which also rotates with the motor and generate four pulses detected by a detector. In case of jamming or some problem due to which the belt does not move in that case the proximity also does not rotate and therefore the pulse which were generated earlier will not be detected now and since the four pulses can not be sensed therefore the belt is stopped. Used in belt conveyors, deep bucket conveyors, rotary air locks, screw conveyors etc.

4.1.4 BOOT LEVEL SWITCH

This is used in bucket elevators through which material is carried to higher levels through a chain of buckets. This switch is present at the bottom of the bucket elevator and therefore its called a boot level switch. Used in bucket elevators.

4.2FOR MEASUREMENT 1)Thermocouple for higher temperature.2)RTD for bearing and winding temperature of motors.3)Pressure transmitter for flow measurement.4)DP transmitter for differential pressure.5)Temperature transmitter for temperature measurement (in PID Loops)6)Current transducer for measuring current of the drives7)Kilowatt transducer for measuring power drawn by the drives.8)Tachogenerator- for measuring RPM9)Vibration Sensor10)Level measurement.

3. Control of process parameter is through DCS supplied by TATA Honeywell, Model TDC 3000. In Lakshmi Cement closed loop (feedback) control scheme is used to run the Plant.4. To check quality of cement production (final product) they use X-ray machine to check the constituents of cement and for raw material they were using BMA (Bulk Material Analyzer).

4.2.1 THERMOCOUPLEAccording to ceback effect if a circuit is formed consisting of two dissimilar metallic conductors and if the two junctions are at different temperature. Then a thermal emf is generated which causes of the flow of current through the circuit

Fig 4.2 ThermocoupleThe emf is a parabolic function of the difference in temperature below the two junctions given by e = At+Bt2 There are many type of junctions like J & K type. In cement industry K type which has Nickel & Nickel chromium as the two wires is used. Hot junction is kept under temperature to be measured. At cold junction MV proportional to difference in temperature is generated. K type has a range of 0-12000C. This mV is measured or detected as it is by LLMUX or converted into mA through transmitter and then detected. Used for cyclone temperatures, kiln inlet temperatures, cooler temperatures.

4.2.2 RTD This works on the principle of temperature dependence of resistance. It is used for temperature measurement. Here Pt-100 type of RTD is used. This means 00C corresponds to 100 ohms. Max range of RTD is usually not more than 4000C.

Fig 4.3 RTD

RTD can be two/three/four wires RTD. The third & fourth wire helps in compensation and therefore more precise measurement. Here usually Pt-100 with 3 wires is used. Mainly used in measuring bearing and winding temperatures of motors.Thermocouples are more accurate and have wider range but RTD is more economic also Pt-100 is lightweight, stable & easily calibrated.

4.2.3 TACHOGENERATOR

In this the armature of the tachometer is connected to the machine whose speed is to be measured. When armature revolves in the field of permanent magnet emf proportional to the speed is generated. This can be measured directly or after suitable conversions to find the speed of the machine. In case of ac tachometers the permanent magnet is rotating type and emf is generated in the stator coil. Used to measure the speed of the fans, weigh feeders etc.

4.2.4 CURRENT TRANSDUCERS

The current transformers is used with its primary winding connected in series with line carrying current to be measured or the line on buss bar itself is made the primary. Therefore it has very few turns so there is not any appreciable voltage across it. The secondary is connected to measuring instrument or transmitter. It has large number of turns.The high current flowing in the primary is step down into the required range (4-20 mA) which can be detected by the instruments in DCS after suitable conversions.

4.2.5 KILOWATT TRANSDUCERS

In potential transformer the primary winding of the transformer is connected across the line carrying the voltage to be measured and the measuring, voltage circuit is connected across secondary winding like in current transformer. Unlike current transformer the potential transformer can be considered as parallel transformer with its secondary nearly under open circuit condition. Together with the potential transformer a current transformer attached in the circuit forms a kilowatt transformer. The primary for both transformers is theline for which measurement is to be made. The high voltage and current is step down to the required range. Transmitter can convert voltage to mA (4-20) and by knowing the angle of potential and current transformer power factor, cos is known.Power is calculated by P = 3 VI cos.

4.2.6 LEVEL MEASUREMENT

Level measurement can be done by many methods: -

-Capacitive type-Vibrating fork type-Radio frequency type-IR type-Ultrasonic type

In capacitive type of level measurement, a plate is attached at a, desired level the other capacitive plate is formed by the bottom of the container when material is filled it acts as the dielectric and the capacitance decreases with the increase in level of material. At a fixed value of capacitance desired level is obtained and the flow of material is stopped.

In case of vibrating fork type of measurement a fork is attached when the material is filled the vibration of fork is reduced and when the vibration is equivalent to the desired level then its detected and the flow is stopped.

In case of RF and IR & ultrasonic source method the RF or IR sensor is at one end and a detector at the other end of hopper. The material allows some rays to pass and absorbs some IR/RF rays therefore by knowing the amount of rays reachingthe detector and the nature of material flowing in the level or amount of material can be determined.

The level measurement can be point measurement or continuous measurement. In case of point measurement the level is determined at any particular point. In continuous measurement the level is measured continuously. Used to measure the filling of the hoppers and silo.

VIBRATION SENSOR

It can be capacitive type or LVDT type of vibration sensor. In capacitive type one of the capacitive plates is kept on the vibrating surface the movement of the plate causes a change in capacitance.Similarly in case of LVDT the core of LVDT moves due to vibration and the secondary of LVDT give an ac output voltage. Used to measure the vibration of the VRM and fan vibration etc.

TRANSMITTER PRESSURE TRANSMITTER

In pressure transmitter, by using diaphragm pressure or draft (- ve press) is measured. One of the diaphragms is fixed and pressure is applied to the other diaphragm. The reduction or increase in value of capacitance depending of application of pressure or suction respectively is measured.

In differential pressure transmitter measurement is made by the difference in pressure causing the movement of both the diaphragm. Used to measure the cooler and kiln drafts.

Solenoid Valve: It is used to change the direction of the diverter. By using solenoid valve air is sent in through one of the two pneumatic inlet ports which cause the movement of piston in cylinder this causes the movement of diverter. Solenoid valve has a plunger by the movement of which the inlet and outlet port open and close and piston of diverter is changed. Used in pneumatic cut off gates.

4.2.7 WEIGHING EQUIPMENTS:

WEIGH FEEDERSLoad cells are attached to the belt, which weigh the weight of material per meter in kg/gm or tons/hr.

Fig 4.4 Weigh Feeder

By using tachogenerator the speed of the belt is measured in m/s considering both the factors we get the weight measured in kg/s on T/H of the material on the belt. Used to measure and control the feed in the VRM and Cement mills.

SOLID FLOW METER

When the material flows on the load cell with a fixed speed the weight is measured in kg/m since the speed and distance is constant therefore only the weight varies. Solid flow meter only measures weight and does not control the flow of material. Used to measure the feed in the kiln.

LOSS IN WEIGHT

This not only weighs the material but also controls the flow of the material. The set point is given from the DCS and the output regulates speed of screw. The controlling is done by microcount, which has a PID loop. The hoppers have a buffer level of 3600 kg or 3.6 tons. When the level goes below this coal starts filling upto a level of 4.5

tons. This is the volumetric mode and at the time of filling the bottom end of hopper is closed. When the filling stops it goes into gravimetric mode and the coal starts flowing through the screws attached below the hopper. The load cells attached to the hopper make the loss in weight measurement if the flow is more than the required set point then the speed of the screw is varied and therefore controlling is done. It is used to measure the coal firing in the kiln.

5. CONTROL METHOD

5.1 DISTRIBUTED CONTROL SYSTEM

There are numerous field equipments in a plant for safety and proper control of these equipments some control scheme is required. There are number of parameters to be checked and controlled (e.g. press, temp, pos) these parameters have to be kept within certain set point for the proper function of plant and good result.In present computer era, most of the controlling part is performed through computer on microprocessor. These turn out to be most efficient.Earlier and even today for small plants one single computer is used to control the whole plant but there were some underlying drawbacks of such a centralized control method. It could not prove its efficiency for lager plants since load will grow beyond its handling capacity resulting in improper control of the plant. The biggest drawback is that if computer fails whole plant will shut down.To overcome these drawbacks DCS, distributed control system came into existence. The control is distributed. It reduces load on particular system and failure of particular node does not affect other nodes and will not lead to the shut down of entire plant. This control scheme is DCS.

We use TATA HONEYWELLS DCS, the TDC 3000.

5.2 SYSTEM CHARACTERISTIC OF TDC 3000

TDC 3000 DCS ARCHITECTURE:

DCS consists of interconnected network, LCN & UCN. TDC 3000 is a data acquisition and control system that can be tailored to meet your specifications. It can be small or highly complex system with hundreds of devices.The backbone of every TDC 3000 is a communication network, local control network. LCN directly links those devices that provide following function.

1.Human interface.2.Mass data storage.3.Intensive advanced Control.4.Interface blow multiple LCNs.5.Interface to computer.6.Interface to process network.

LCN MODULES

There are 13 LCN modules 8-USs, 3 NIMs and 2 HMs.The devices connected directly to the local control network are called LCN modules. The standard modules according to their functions are -

1) UNIVERSAL STATION (HUMAN INTERFACE)

US is primary TDC 3000 human interface, it allows an easy and quick access to data in any part of system. It has memory of 2 Mb & 3 Mb. An US can be programmed to draw the schematic of different parts of plant using graphical technique.

It works in three modules, called its personality.

-Engineering personality.-Operator personality.-Universal personality.

Engineering Personality: The user is allowed to create on alter database, display and load system software from HM on any storage device.Operator personality: Can see or send only object files. Operator monitors or controls process and change process parameters through US and is not concerned with technical aspects.Universal personality: Can work in both engineering and operator modes.System & process operation function includes following:

1.Monitoring & manipulating continuous & discontinuous operation.2.Anticipating and handling alarms.3.Displaying and printing trends, logs, journals and reports.4.Monitoring and controlling system status and diagnostics.

Process engineering functions includes following.

1.N/W configuration.2.Building process database.3.Building custom graphics.4.Designing reports.5.Preparing control language programs.

Maintenance function includes.

1.Diagnosing system problem.2.Displaying and printing information required during trouble shooting.

Design benefits:

1. Incremental expandability The functional specification of physical module allows starting with those devices of internal requirement and available funds. Expansion can be done by simple addition of hardware module without reprogramming of software.

Global database: TDC 3000 system function with a single database accessible to all users by single access mechanism, which minimizes engineering costs.

2.History Module: It consists of hard disk a SMC card and a LCN interface card. Its main function is to store data and system files. Data is stored on hard disks. SMC card is connected to hard disks and LCN interface card. Personality of HM is loaded on SMC card, which controls operation of disk and fetches the data from the disk. It in turn supplies data to LCN interface card.There are two history modules linked with LCN. HM is used for mass data. Storage and therefore consists of hard disk. Helps in storage and quick access of large blocks of data.Stores process alarms, system status change, system files of all types and other data when module is reloaded or US personality is changed required data and system files are accessed from HM.

3. NIM Network Interface ModuleIt provides an interface between UCN & LCN. NIM carries all the information of the exiting data points in network.

UCN based distributed control

Designed to be compatible with IEEE and ISO standards UCN is high-speed high security process network. Its peer-to-peer communication capability allows for easy sharing of process data, making it convenient to implement sophisticated control schemes involving more than one process Manager, APM, LM or combination of these.

UCN Modules:

Devices directly linked to UCN.

1.LM: Logic Manager

It performs digital and analog logic control function as an integral component of Honeywell TDC 3000 DCS. The LM provides process automation for control, communication monitoring of specific processes and a peer-to peer link with the process manager system, or other LMs on the UCN.LM system has high-speed programmable controller processor, power supplies, option modules, serial and parallel I/0 links to field devices and a LMM that provides an interface between the processor and UCN.

LM is programmed with ladder logic. LM system scans its I/0 interface, executing control program for output devices and provides input status collected from input devices. This information is processed and converted to UCN data format.LM system consists of single/redundant LM processor. Redundancy in LM system involves a single I/0 system controlled by dual process. Two redundant control modules that reside in one-logic manager processor card files manage redundancy.

LM Processor: It is composed of multi-modular units (cards) featuring remote serial and local parallel I/0 capability. The memory is expanded to 32 K from 29 K words of memory. The LM is designed to service high speed and complex control operations.

LM I/0 System: It offers several options for interfacing LM processors to sensors and actuators of plant floor. The parallel and serial I/0 system includes a wide variety of discrete analog special function I/0 modules and related I/0 hardware. The I/0 system consists of many different i/p, o/p modules with varying number of points and voltage types designed for compatibility with many different kind of field devices and power sources. The LM gathers and measures physical machine or process, variables such as proximity, pressure, temperature and voltage through I/0 interface. Based on this status the LM processor then issues commands to control the devices being mentioned (alarms, control relays, motor, pump & valves)

The I/0 system may be set up with the LM system in several configurations. A parallel configuration is used for local placement of the control processor and I/0.

Serial configuration permits I/0 to be located thousand of meters away from the processor. This configuration also minimizes field wiring.

HPM (High Performance Manager)

Designed to provide flexible and powerful process scanning and control capability. It uses powerful multiprocessor dedicated to perform specific tasks. It consists of HPMM & I/0 sub-system.HPMM consists of communication processor and modem, I/0 link interface processor and control processor. HPMM redundancy can be optionally provided.The communication processor is optimized to provide high performance. N/w communication handling such functions as n/w data access and peer-to-peer communication. The control processor is the HPM resource dedicated to executing regulatory, logic and sequence functions. The I/0 link interface processor is the interface to the I/0 sub-system.The I/0 sub-system consists of redundant I/0 link and the I/0 processor. These I/0 processors handle all fields I/0 for both data acquisition and control functions. The I/0 processor provides functions as engineering unit conversion and alarm limit checking independent of HPMM. All control operations are performed in HPMM, with all data acquisition being performed in I/0 process. The process engineer has complete flexibility of choice.

HPMM card file options: The basic advanced process manager sub-system configuration consists of a single. High performance manager module residing in HPMM card file. The card file also accommodates upto 10 IOP cards.The redundant HPM sub-system has two configurations:1.An HPM sub-system in which primary & secondary HPMMs resides in the same card file with also upto 5 IOPs. The card file is designated redundant HPMM card file.

2.The preferred redundant configuration is comprised of 2 HPMM card files with HPMM in each. This provides:

1-A primary HPMM.2-A redundant HPMM3-40 IOP card slots.

This alternative redundant HPM sub-system can be configured with the redundant card file installed in the same cabinet or in another cabinet of a cabinet complex with a separate power system. A redundancy cable connects two HPMM together.

HPM Architecture

HPM consists of:1.HPMM2.Redundant HPMM card files.3.Filed termination assembly.4.Power system.

HPMM provides:

1.Communication with LCN n/w interface modules through UCN.2.Communication through I/0 link interface with IOPs processors.3.Memory for control processor database.4.Control processor.5.Redundancy control.

Process Manager Modules are comprised of five cards listed below:Modem A mod/demod circuit board that interfaces with UCN. Its job is serial to parallel conversion and vice-versa.

Advanced I/0 link interface Provides communication link to the IOPs.

Advanced communication A communication controller that interfaces with modem card. Provides external peer-to-peer communication.

ADVANCED CONTROL Provides control processing and calculating provides the drive capability for exclusive redundancy interface blow redundant HPMMs. All the points built in HPM came in this module.

FILLERA non-functional card (blank use)

In HPM there are 3 files and in each these are 15 modules i.e.total 45 modules, out of these first 5 in file 1 is called HPMM. The remaining 10 are IOPS.

I/0 PROCESSORS USED IN LAKSHMI CEMENT

High level Analog Input (HLAI)Low level Analog Multiplier (LLMUX)Analog output (AO)Digital output (DO)

Additional IOP card files slots can be added to any HPM.

HIGH LEVEL ANALOG I/PAccepts upto 16 high level inputs. The inputs are configurable as single ended on differential in relation to mater reference ground.

ANALOG OUTPUT:Provides 4-20 mA outputs to proportioning cards such as valves:

DIGITAL 0/P Provides 16 O/P that is isolated from each other.

LLMUXThe FTA accepts one set of 16 low-level inputs such as thermocouples or RTDS. The inputs are sequentially multiplexed.

QUALITY CONTROLTo check the consistency of cement: 2 X-Ray machines are used one by Philips and the other by Oxford. Presently, Oxford MDX 1000 is in use, which consists of a floor, standing XRF spectrometer and an associated PC.The principle on which it works is the multi depressive X-ray fluorescence allowing quantitative multi-elemental analysis. It is based on windows and uses XpertEase software. It requires single-phase supply and may also need helium for some applications like liquid analysis.As soon as the power is switched on the window is automatically loaded. In XRF menu icon software will start and XpertEase start up window will appear. The lid is removed and the pallet is inserted. This pallet goes inside and the shutter is removed so that the X-rays fall on the sample and analysis is done. There are spectrometers attached for each constituent. The entire report is obtained on the PC, which displays the analysis. This analysis is done for checking quality of clinker produced in the kiln.

For checking the quality of raw material from mines Cross Belt Analyzer is being used.

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