09-09-2014, 04:03 PM
A CASE STUDY ON COAL HANDLING PLANT AND WORKING OF ROTARY DISCHARGE MACHINE PROJECT REPORT
A CASE STUDY ON COAL.docx (Size: 1.61 MB / Downloads: 16)
ABSTRACT
CHP is (C-Coal, H-Handling, P-Plant) a plant which handles the coal from its receipt to transporting the coal to the unit bunkers of KTPS-V & VI stage and from there to boiler and also to the UCCY(un crushed coal yard) and CCY (crushed coal yard) for stocking purpose. It also processes the raw coal to make it suitable for Boiler operation. In brief we can say that receipt of coal to various coal mills bunkers. This is the responsibility and duty of the CHP its staff.
In CHP coal is unloaded from wagons to the track hopper in which the whose coal is deposited and it has to transfer to the conveyor belts properly, in order to perform this operation “ROTARTY DISCHARGE MACHINE” is used which discharged coal from track hopper to the conveyor belt.
Rotary Discharge Machines ensure the reliable discharge of totally different bulk materials such as coal, limestone, marl, dolomite stone, natural and FGD gypsum. Minerals or additives from silos, hopper or piles. In coal handling plants the Rotary Discharge Machine is used to discharge coal from Track Hopper to the running conveyor belt. Equipped with an electric control, the Rotary Discharge Machine moves within the discharge channel on rails in both travel directions. Thanks to the logarithmically curved discharge arms. Even bulk materials with poor flow properties can be discharged uniformly. The rotary discharge machine is adaptable to completely different applications and depending on the requirements, comes in block or low profile design. The rotary discharge machine travels on the support structure of discharge belt conveyor along the hopper table. In the swiveling version, the rotary discharge machine travels to the pre-selected areas where it discharges the bulk materials.
INTRODUCTION
Kothagudem thermal power station is a coal fired thermal power generating station with total capacity of 1000MW out of which
Recently during 1996, one more stage KTPS – V stage was constructed which consists of two units 9 & 10 each of 250MW capacity.
The KTPS –VI stage consists of unit 11 of 500MW capacity.
Thus the total installed capacity of the plant is:
KTPS - V Station: 2*250=500MW (Commissioned in the year 1996)
KTPS - VI Station: 1*500=500MW (Commissioned in the year 2011)
TOTAL = 1000MW
KOTHAGUDEM THERMAL POWER STATION STAGE V & VI
The KTPS – V & VI stages are the one which is highly technical and has more advantages. Units 9, 10 & 11 of KTPS – V & VI stages were successfully completed and commissioned in a record time of 31 & 28 months respectively after commencemt of work.
Supply of Water
The Kinnerasani Project which is 10 KM away from the plant is the only source of water supply to the KTPS. The Kinnerasani Dam was constructed at a cost of Rs.5.6 Cores and was maintained by the Irrigation department up to March 1998.
The project was taken over by APSEB/APGENCO on 01.04.1998. Remedial and Modernization works at a cost of Rs.5.6cores have been carried out to ensure storing of water to full reservoir level of 407
The Kinnerasani Project which is 10 KM away from the plant is the only source of water supply to the KTPS. The Kinnerasani Dam was constructed at a cost of Rs.5.6 Cores and was maintained by the Irrigation department up to March 1998.
The project was taken over by APSEB/APGENCO on 01.04.1998. Remedial and Modernization works at a cost of Rs.5.6cores have been carried out to ensure storing of water to full reservoir level of 407
WAGON TIPPLERS
The rotary tippler designed for unloading broad – gauge open railway by inverting wagon by inverting on its own centre of gravity through an angle of 1700, there by discharging its contents into hopper below rail. ( The tippler is designed to handle wag-ons having a gross load up to 110 tones, height from 2,250mm (min) to 3,735 mm max) and a maximum overall width of 3,500 mm. The tippler ensures handling of wagons, without any damage.
The tippler consists of two circular rings, a platform with travel rails, support rollers, two girders as well as clamping device, which retains the wagon from the top as well as from the side during tippling.
The tippler is driven by a drive unit located on one side of tippler. The driver unit consists of motor-with flexible coupling; thruster operated brake, helical gearbox, pinion and toothed rings. The Size/type of drive is decided on the number of tips/hour required.
The complete hydraulic equipment, including the motor and the oil tank are located on the tippler itself and rotate along with the tippler. Top clamps and side beam are hydraulically operated. Wagon is clamped before tippling operation. The top clamps and side beam are lined with rubber pads throughout the length of the tippler, which reduces the pressure on wagon walls.
VIBRATING FEEDER
Vibrating feeder consists of vibrating frame, spring, vibrator, motor vibrating device and motor. The vibrator is made of two fixed eccentric shafts whose gears are jogged. When installation, the two gears must be jogged according to the sign. Through drive of the motor, the two eccentric start rotating to produce a linear huge power which forces the feeder to vibrate. Through the vibration, the materials will slip on the funnel, moving forward, when the materials pass the screening part, smaller parts will fall down, and avoiding the further crushing, so screening purpose can be reached.
Vibrating Feeder Application
Vibrating feeder is a kind of linear direction feeding equipment. It features smooth vibrating, reliable operation, long service life and suitable for feeding. They are widely used in mining, building-materials, silicate and chemical industry in the crushing and screening plants. In the sand-stone production line, it can send materials to crusher even and continuously and at the same time, it can screen materials roughly. It can be used in these areas such as metallurgical industry, coal mining industry, mining-selecting, building, chemical and grinding industry, etc.
ROTARY DISCHARGE MACHINE
Rotary Discharge Machine ensure the reliable discharge of totally different bulk materials such as coal, limestone’s, marl, dolomite stone, natural and FGD gypsum, minerals or additives from silos, hopper or piles. In coal handling plant the rotary discharge machine is used to discharge coal. Equipped with an electric control, the rotary discharge machine moves within the discharge arms, even bulk materials with poor flow properties can be discharged uniformly. The rotary discharge machine is adaptable to completely different applications and depending on the requirements, comes in block or low profile design. The rotary discharge machine travels on the support structure of the discharge belt conveyors along the hopper table. In the swiveling version, the rotary discharge machine travels to the pre-selected areas where it discharges the bulk materials
CONVEYOR BELTS
Conveyor belts play a crucial role wherever raw materials, parts and products have to be transported in mining, industry and commerce. Our conveyor belt fabric provide conveyor belts with the performance required by companies on all continents.
These range from the mining to the automotive industry and even includes logistics centers. Conveyor belts frequently convey weighing tones, especially in mining sector, and are exposed to enormous stress on a daily basis. Therefore, the manufacturers of conveyor and transport belts specify differing requirements, depending on the application.
COAL CRUSHER
Coal crusher is a type crusher of are crushing equipments used for crushing coal. Coal crusher is acknowledged well in coal processing industry for a long time. It is used widely in coal mining and coal processing because of its advantages. SBM is a major coal crusher manufacturer and supplier for power plants, coke ovens or other related coal crushing company. As the largest exporter in the design and manufacture of coal crushers and spare parts, SBM coal crushers are used in wide variety of material reduction and processing applications in 100 countries around the world.
ROTARY DISCHARGE MACHINE
Rotary Discharge Machine ensure the reliable discharge of totally different bulk materials such as coal, limestone marl, dolomite stone, natural and FGD gypsum, minerals or additives from silo, hoppers or piles. In coal handling plant the rotary discharge machine is used to discharge coal. Equipped with an electric control, the rotary discharge machine is used to discharge coal. Equipped with an electric control, the rotary discharge machine moves within the discharge channel on rails in both travel directions. Thanks to logarithmically curved discharged arms, even bulk materials with poor flow properties can be discharged uniformly. The rotary discharge machine is adaptable to completely different applications and, depending on the requirements, comes in block or low profile design. The rotary discharge machine travels on the support structure of the discharge belt conveyor along the hopper table. In the swiveling version, the rotary discharge machine travels to the pre-selected areas where it discharges the bulk material.
The block type rotary discharge machine is designed for two-sided discharge of a wide variety of bulk materials from longitudinal hoppers or silo batteries. The machine equipped with hydraulic drive and frequency converter discharge the bulk material over the hopper table at a controlled rate.
FUNCTIONAL DESCRIPTION AND HYDRAULIC UNIT
Louise Rotary Discharge Machine are used for discharging bulk materials from continuous slot bunkers
Where by the materials is delivered over into a belt conveyer situated below the machine. Apart from its discharging function, the rotary discharge machine (RDM) effects a cross section mixing of the materials within the bunker. This is particularly advantageous in cases, where the bunker is loaded with different materials and the material discharged, is required to be mixed and chemically as uniform as possible.
Discharge is carried out by means of discharge wheel consisting of six logarithmically curved discharge arms, screwed onto the discharge wheel hub. The discharge wheel hub is mounted on the vertically down ward pointing drive pin of the discharge gear mechanism.
HYDRAULIC CIRCUIT
The hydraulic unit comprises the following integrated safety mechanisms:
A dual pressure control device for setting monitoring pressure for the discharge wheel gear mechanism, plus pressure switch at the return filter.
The dual pressure control device is equipped with two switching contacts.
The first contact closes, when the reversing pressure, which is lower than the switch-off pressure, is reached. The RDM stops, reverses its direction of travel, stops again a preset time and returns to its original directions. The reversing pressure is preset to a fixed value in ours work and must not be changed !.
The second contact opens, when the preset switch-off pressure is reached, and switches the Rotary Discharge Machine Off. The switch off pressure is preset to a specific value in our work and must not changed!
The pressure switch for the return filter will give a warning indication, when the filter is clogged. It is preset to a fixed value too and must not be changed.
MACHINE ELEMENTS
SERVO MOTOR
A servo motor is a motor which forms part of a servo mechanism. The servo motor is paired with some type of encoder to provide position/speed feedback. This feedback loop is used to provide precise control of the mechanical degree of driven by the motor. A servo mechanism may or may not use a servo motor. For example, a household furnace controlled by a thermostat is a servomechanism, because of the feedback and resulting error signal, yet there is no motor being controlled directly by the servomechanism.
Servomotors are not the only means of providing precise control of motor output. A common alternative is a stepper motor. In a stepper motor, the input command specifies the desired angle of rotation, and the controller provides the corresponding sequence of commutations without the use of any feedback about the position of the system being
CABLE TROLLEY SYSTEM
It is the system in which the cables are mounted like a trolley along with the track and the cables are connected to the RDM and moves along with it.
The parts used for this cable trolley system are of galvanized steel. The four guiding rollers have ball bearings and guarantee easy running in the special profile rail. The cables are clamped with rubber plates made of neoprene, an appropriately sharp bends at the clamping point. Installation depends on various criteria, e.g., maximum cable sag (cable weight) and working length.
LOCAL CONTROL
The term “local control” means operation of the RDM by the control elements on the control panel mounted on the machine.
For this purpose, move the key-operated switch “local control/remote control “into its “local control” position. This will be acknowledged by the illumination of the “local control” indicator lamp
SETTING OF DISCHARGE WHEEL SPEED
The discharge wheel speed is infinitely variable by means of the preset potentiometer in the local control cubicle.
The instanteous discharge wheel speed rate is picked up a proximity switch “actual value” with an output frequency proportional to the discharge wheel r.p.m.-rate. For
Further processing, these square-topped pulser are transferred to an electronic p.c.-card in the Comtronic, which converts the pulses into a 4-20mA current.
This current is used to indicate the capacity in present on the local control cubicle.
At maximum speed, the contact “limit switch control pump output max.” is opened. A further speed increase is not longer possible now.
If the different speed is required, the desired direction. The discharge wheel speed automatically rises or falls to the new value.
CONCLUSION
The scope of work for this project has been achieved, as well as all the individual tasks.
A good grasp of KOTHAGUDEM THERMAL POWER STATION – COAL HANDLING PLANT was achieved during the project on coal handling plant.
During the review of the coal discharge system to the conveyor belts the understanding of working of each individual machine that can be in coal handling plant was achieved. Furthermore, the basics of coal handling plant and working different coal handling plant machinery was achieved in the review process.
During the review with Rotary Discharge Machine , the design and working of RDM is studied.
Overall a good frame work for this project is achieved