ASH HANDLING PLANTINTRODUCTION TO ASH HANDLING PLANT: Large quantity of ash is generated in coal based thermal power stations. This huge quantity of ash, considered an environmental pollutant, requires huge quantities of water and large tracts of land for its safe disposal in the conventional ash handling systems. This huge quantity of thermal plant waste i.e. ash is fast becoming a useful resource / material needing products quality of various required standards for different applications. This emerging utilization potential of ash now calls for promoting technological advancements in ash collection and storage systems with in built facilities for bulk utilization applications as well as meeting stricter environmental norms. Keeping in line with the above requirements the dry ash handling system as NCPS / Dadri has been designed and provided with in built facilities to facilitate bulk utilization of ash besides conserving land and requiring less water for ash disposal purpose. 45 ASH HANDLING PLANT Overview of NTPC Dadri (Thermal Plant): • • • • • • • STATION CAPACITY COAL CONSUMPTION ASH GENERATION ASH DISPOSAL DRY ASH SYSTEM Transportation WATER REQMT. FOR ASH CONDITIONING ASH MOUND AREA : 20 % by Weight : 375 acre : 840 MW : 3.66 Million T / Year : 1.5 Million T / Year : Dry Ash System : Vac. Extraction & Pr. Flue Gases & Fine Ash Coal Consumption /Day/Unit= Ash 3000T Generation /Day/Unit( 34% ) = 1000T (Approx.) Economis er APH ESP Bottom Ash Hopper CAT APH + ESP =80% of Total Ash System (800 T /Day Dry /Unit) BA + CA =20% of Total Ash Slurry System (200 T /Day /Unit) 46 C pH Bulk Density : 64. Al2O3 Ferric Oxide.81 gm/ml 47 .84-2% : 0.05% : 0.55% : 0.57 % : 24.84% : 0. Fe2O3 CaO MgO P2O5 SO3 Na2O Potassium Oxide Carbon.08% : 6.10 : 0.5 % : 8.ASH HANDLING PLANT CHEMICAL COMPOSITION OF FLY ASH: • • • • • • • • • • • • Silica.15% : 0.36% : 0.4% : 0. SiO2 Alumina. 1 : 10 ratio and the slurry formed is transported through the pipelines to remote ash bund area by means of ash slurry disposal pumps. PROGRESSIVE RESTORATION OF ASH DISPOSAL SITE AS USEFUL LAND. dry ash is handled and water required for this system is only for providing the moisture to ash to control the fugitive dust during process. 5. land required for ash mound area is 0. Conventional ash handling system. total 375 acre land is acquired for ash mound which is designed for 25 years ash output of four 210 MW units i. minimum 1.45 acre land per MW of generation capacity for 25 years is required in dry ash handling system. LESS WATER REQUIREMENT: In conventional method i. LESS REQUIREMENT OF LAND: Approx. Approximate ash water ratio in this system is 10 : 1.e.8 acres per MW of generation capacity for 30-35 years. FACILITATE LARGE SCALE UTILIZATION OF ASH. only 0.ASH HANDLING PLANT DRY ASH HANDLING ADVANTAGES: SYSTEM AND ITS The concept of dry ash handling has been utilized for the first time in India at a NTPC Dadri. This layer allows water to flow freely to the perimeter ditch and protects the ground water from toxic leach ate contamination. requires enormous land water and has associated problems of leaching effect. before putting PFA.e. 2. Some major aspects with respect to dry ash handling system that make it more favorable in comparison to conventional method of wet disposal are: 1. 4. 48 . lean slurry disposal system of ash. At NTPC Dadri. dust blow etc. ELIMINATES UNDERGROUND WATER AND SURROUNDING WATER WAYS POLLUTION: At NTPC Dadri. 3. At NTPC Dadri.00 meter thick drainage blanket is laid over the ground with FBA. is ash is mixed with water in approx. ASH HANDLING PLANT SALIENT FEATURES OF INSTALLED SYSTEM: • • • • • Extraction & transportation of fly ash in complete dry form. 49 . Construction of Ash Mound in a systematic manner. Complete re-circulation of water for Bottom Ash Handling System. Unloading & Transportation of conditioned ash from Silo’s & decanted bottom ash from Hydrobins on to belt conveyor’s. System having provision to store selected grade of ash in separate Silo (Silo-3). Bottom Ash / Coarse Ash Removal System Economiser Hoppers LP Water HBN-1 Flushing Apparatus HBN-2 HP Water CAT LP Water OFT OFP-1 & 2 HP Water Bottom Ash hopper BAH Gates HBN-3 CG CG 50 . The decanted water from hydrobin is transferred to setting tank / surge tank for re-circulation. is continuously collected in water impounded bottom ash hopper and periodically transferred to the hydrobin by means of jet pumps and associated pipe lines. FURNACE BOTTOM ASH (FBA): Bottom ash. is the removal of ash from 4x210 MW plant and their associated economizers. resulted from the combustion of coal. air pre-heaters and electrostatic precipitators to the ash mount area. Each bin discharges de-watered ash onto its dedicated reversing belt conveyor. Stage-1. From hydrobin. the settled ash is transported by conveyors to the ash mound area. In one direction the ash is transported to ash mound through series of belt conveyors and in other direction ash can be loaded into lorries for various ash utilization purposes.ASH HANDLING PLANT GENERAL DESCRIPTION OF ASH HANDLING PLANT SYSTEM: The Ash Handling System at Dadri. Hydrobin is decanted through a floating decanter and 10 stationary decanter columns. two operating and one standby. for its further removal to the ash mound area. A pressure relief door is mounted on the top of the silo to relieve any excess pressure from the silo. For buffer hoppers. the fly ash is to be deposited. The conditioned fly ash is discharged to a running belt conveyor (to be supplied by others) located below the hydromix dust conditioners. is continuously cleaned during system operation. Segregating valves in each pressure transport line. flushing apparatus. Arranged fan rows around the outlet adopter opening in the silo floor. by means of vacuum pumps. The fly ash falls from the bag filter down into the silo. Water is sprayed through nozzles on the fly ash inside the hydromixer to condition the ash. silo-2 and common silo. dry ash is pneumatically conveyed. Pulsating air is supplied to clean the fly ash from the exterior surface of the filter bags. via. Each silo is provided with three hydromix dust conditioners. Each 51 . Located at the fly ash storage silo. while the conveying air passes through a vent filter mounted on the silo roof and is discharge to the atmosphere. each silo is provided with three more outlets for removal of fly ash as an alternative arrangement. Altogether five silos are provided for all the four units. via pipe lines to the storage silos for its further removal to the ash mound area by means of belt conveyors. controls which of the three silos. Thus fly ash from unit-1 can be transferred to silo-1. aerate the dust in the silo and functions continuously irrespective of whether silo is used as storage of being loaded/unloaded. for the removal and conditioning of fly ash in a moist state. Apart from hydromix dust conditioners. Alternative the de-watered hydrobin ash can also be unloaded to trucks through the reversible belt conveyor. Alternate arrangement is provided to load the unconditioned dry ash from silo to closed trucks. Hydromix dust conditioner is supplied with fluidizing feeder and metering cut off gate.ASH HANDLING PLANT The coarse ash from economizer hoppers is also transferred to the hydrobin. coarse ash tank and pipe lines. PULVERIZED FLY ASH (PFA): Fly ash from air pre-heater collection chutes and electrostatic precipitator’s collection chutes is continuously removed to the buffer hoppers located near the ESP. When the fly ash reaches the silo it enters a target box and falls by gravity into the silo. The vent filter. installed on the top of the silo. Provision is also made in the system to collect separately the saleable and non saleable ash. Out of five silos one silo is common which receives fly ash from both the transport lines of all the four units and remaining each silo receives fly ash from both the transport lines of only two units. Air slides. Ash is unloaded through feeder in dry form on to a closed truck. Each silo having the capacity of 2500 MT where as hydrobin capacity is 650 MT. one solenoid operated plate valve. one rotary feeder and one telescopic chute.ASH HANDLING PLANT outlet is having one manual isolation valve. 52 . The unloading of silo through rotary feeder is controlled only from local control station. whereas unloading of silo through hydromix dust conditioner can be controlled either from local control station or from conveyor control panel. Each Buffer Hopper is connected with an individual Vacuum Pump of 50 m 3 /min capacity at 16 inch Hg Vacuum. The varying line vacuum is used to control system operation. Thus two in service & two stand-by. The material handling valves operate sequentially through the hopper rows. When the vacuum reaches the system vacuum set point. When the hopper is empty the vacuum will fall to the low set point and the material handling valve closes. This results in increase of line vacuum. [Fly ash enters the transfer hopper (buffer hopper) and is directed downward by means of a stone box arrangement. Each set is connected with two sets of Buffer Hopper.29 kg /cm 2 each) & Transport Air Line (1 km each) in each Unit. per Buffer Hoppers) inbuilt in the Buffer Hopper separate ash from ash-air mixture & ash is being collected in the Buffer Hopper. The transfer hopper is provided with 53 . There are four buffer hoppers & four Vacuum Pumps in each Unit. It opens initially after establishing a system operating vacuum and cycles close and open between the full load and no load set point. There are two sets of Transport Air Compressor (150 m 3 /min at 2. the system is signaled to advance to the next hopper in sequence. From ESP/APH hoppers to Silos through Dry Ash Handling System & Bottom Ash Hoppers/Economizer Hoppers to Hydrobins through Wet Ash Handling System. [Vacuum switches installed in the vacuum line transmit signals to the programmable controller.ASH HANDLING PLANT DETAILED PROCESS OF ASH DISPOSAL SYSTEM: The Ash Handling Plant comprises of two major sub-systems: 1. DRY ASH HANDLING SYSTEM: • The Dry Ash is evacuated from 24 ESP & 4 APH hoppers and is transported to ash storage Silos continuously in two stages. Thus one set running & other stand-by. One set of Buffer Hopper & Vacuum Pump collects ash from 12 ESP & 2 APH hoppers. Bag Filters (81 nos.] • Secondly from Buffer Hopper to Ash storage Silos through pressure system. • First from ESP & APH hoppers to Buffer Hoppers through Vacuum System. Two air lock tanks are installed below each transfer hopper. An equalizer valve controls the pressure in the air lock chamber. In HMDCs Fly Ash is being conditioned (Ash : Air :: 80 : 20 ) & unloaded in conveyor belt and sent to Ash Mound. The system has provision for storage of segregated fine fly ash from ESP hoppers to Silo-3. Silo 3 is common for all the four Units for saleable purpose. After Clinker Grinder the slurry line is evacuated by Hydro ejector ( inlet Pressure 20 kg /cm 2 & outlet Pressure 4 kg /cm 2) and sent to Hydrobin (650 cu. for a group of two Units. is continuously cleaned during system operation through solenoid operated pulsating air system. The plant has six Hydrobins for four Units. 54 . the equalizer valve is connected with the transfer hopper to ensure the pressure in the air lock tank is equal to the transfer hopper.ASH HANDLING PLANT aeration air to assist in maintaining the fly ash in fluidized condition. installed on the top of the buffer hopper. M) through Slurry Line (1 km long). the equalizer valve shifts position. When the top gate closes. • Each Unit has four Clinker Grinders including Gate Housing and two slurry lines. The Silo’s 1-2-3 for Units # 1 & 2 and Silos 3-4-5 for Units # 3 & 4. When top gate is open.] • The plant has 5 fly ash storage Silo’s (3000 m 3 each) for four units. Through Rotary Feeders dry ash is unloaded in closed truck. • Each Silo has three Hydro Mix Dust Conditioners (200 T /hr each) & three Rotary Feeders. Three nos. allowing air from the transport air compressor to pressurize the air lock tank and assist the flow of fly ash when bottom gate opens. The bag filters. BOTTOM ASH HANDLING SYSTEM: • The Bottom Ash impounded into Bottom Ash Hopper (194 m 3) and fed into Clinker Grinder through Bottom Ash Hopper discharge Gate. Aeration above each gate assist to maintain the fly ash in fluidized condition.Each air lock tank has an inlet or top gate and outlet or bottom gate to control fly ash flow from trans hopper to silo. operated simultaneously. It takes 8 to 10 hours & then unloaded to conveyor belts through Vibrofeeder and send to Ash Mound. From Over Flow Tank the water is being recycled to Settling Tank through Over Flow Pump (200 m 3 /hr) and Over Flow discharge line. And afterwards ash settles down & water overflows to the Settling Tank.ASH HANDLING PLANT • The coarse ash from economizer is flashed by LP water and collected in Coarse Ash Tank. All the HP & LP pumps are taking suction from Surge Tank. • Fly Ash collected in Silos & Bottom Ash decanted in Hydrobins transported to Ash Mound area by a series of belt conveyors system and ash is dumped in a systematic manner. • Bottom Ash Hopper evacuation done once in shift. Gradually Ash level rises in the Hydrobin. 55 . Transportation of conditioned Ash from Silos & Decanted Bottom Ash from Hydrobins to Ash Mound Through Conveyor belts and construction of Ash Mound in a systematic manner. Further evacuated through hydro ejector & and sent to Hydrobin through Slurry Line. Economizer flashing to Coarse Ash Tank. • Initially Hydrobin is filled with water. Normal evacuation time by two hydro ejectors is 45 minutes. Water drained through decanter plates to settling tank. 2. In Hydrobin ash is being separated & collected and water overflows to Settling Tank (750 m 3). Evacuation of Coarse Ash Tank once in a shift by 20 minutes through one hydro ejector. Normally after six Bottom Ash Hopper deashing around 400 T of ash accumulated in the Hydrobin. • LP water pumps (each 294 m 3 /hr at 6 kg /cm 2) feeding water for Bottom Ash Hopper filling/over flow. All the three water overflows to Over Flow Tank (24 m 3). • Ash can be damped in three different areas in ash mound area depending upon the system availability and weather condition. • Normally ash is damped in permanent ash mound area through Spreader-I & II. Then the Hydrobin taken under decantation. Seal Trough make up. and further overflows to Surge Tank (1500 m 3). • In case of non-availability of permanent as well as temporary stock yard. ash is being dumped in Temporary Stock Yard through Stacker from where it is reclaimed to the permanent Ash Mound through Reclaimer. 56 . ash is being dumped in Emergency Stock Pile from where it is reclaimed with the help of mobile equipments like dumpers & dozers.ASH HANDLING PLANT FROM 1ST UNIT Silo Vent Fan BAG FILTERS SILO UNLOADING SYSTEM TARGET BOXES FROM 2ND UNIT BAG FILTERS Silo Vent Fan . Ash Storage Silo: Capacity 2949 m3 each 6 deg ROTARY FEEDER HEATER ELESCOPIC CHUTE VENT FAN TELESCOPIC CHUTE SAB-2 SAB-1 HMDC DRY ASH INTO CLOSED TANKERS CONDITIONED ASH INTO OPEN TRUCKS ASH MOUND • During rainy season or system non-availability. Conveyors are selected on control desk by selector switches.conveyor belt. M. C32. Average ash unloading is done 4000 T /day. environmental EXISTING OPERATIONAL PRACTICES TO UNLOAD DRY ASH FROM SILO TO ASH MOUND: • • • • • • • First of all path is selected to unload fly ash / bottom ash. ash mound will spread over an area of 375 acres which will go up to a height of 55 meters with top most flat area of 140 acres. erosion and considerations of noise dust and waterborne pollution. The maximum side slope of ash mound will be 1:4 it will hold 53 million cubic meters of ash. • • • • • • 57 . C-30/31. CA/CB.8 hours per day to evacuate this quantity of ash. Operated belt sway. System runs 7 . Selected conveyors are made healthy electrically from their modules. Generally silo unloading is done in 1st Shift and hydrobin in 2nd Shift or as per requirement / availability of system. CD/CC. For HMDC's operation . C-24/25. pull cord etc. All the flap gates are positioned on selected conveyors manually or electrically at various junction houses (JH's). Machine conveyors are started from its local control panel. C-20/21 and Silo Conveyor C-01 to C-05 or Hydrobin Conveyor C-10 to C-15 are selected and started from ash mound control room. Individual location operator gives the clearance through p. Than C-33. Ash mound system is designed for 25 years ash output of four 210 MW units & one 500 MW unit.S. Instrument air compressor should be in running condition. system before start the conveyor belt. Belt loading capacity is 2000 T /hr. Conveyor belt system is used to unload dry / bottom ash from silo and hydrobins. System is designed to run in two shifts. water pump and silo aeration blower. Protection device switches are normalized. System is started in backward sequence from machine SP-1 / SP-2 / Stacker / SC-2 as per selection of ash unloading area. C-22/23.ASH HANDLING PLANT THE ASH MOUND: Out of 500 acres of land for the dry ash disposal system. The mound design covers stability.a. Short. ash is dumped in "temporary stock yard area" from where ash is transferred to permanent ash mound area through re-claimer machines. Due to this practice Utility factor of this system is 32 and system running hours is 210 220 hours per month. Modular section of belt conveyor structures of shiftable field conveyor are mounted on pontoons which can be easily towed by bulldozers sideways with the help of special shifting attachments during horizontal shifting of conveyor. c) In case of non-availability of systems for permanent & temporary ash mound area. Each silo takes different time to become empty. 58 . On completion of silo / hydrobin unloading system is stopped from silo / hydrobin Conveyors and then other conveyors are also stopped in forward sequence. intermediate modules on pontoons are added or removed to change length. ASH CAN BE DUMPED AT THREE DIFFERENT AREAS IN ASH MOUND DEPENDING UPON SYSTEM AVAILABILITY & WEATHER CONDITIONS: a) Normally ash is taken into permanent ash mound area with the help of boom spreader machine which receives ash from a tripper car lane the final shiftable field conveyor and deposits the ash to 15 meters height up to 60 meters from the center line of shiftable conveyor. Shifting attachment mounted bulldozers facilitate the shifting of conveyor in assembled condition to a new location. b) During rainy season or system non-availability (like during horizontal shifting of field conveyor). Silos are evacuated upto empty limit daily.ASH HANDLING PLANT • • • • Each silo pressure is depending on per day coal consumption. ash can be transported to emergency stockpile from where it is reclaimed with the help of mobile equipment. Head and tail units mounted on skids can be either towed by bulldozer sideways or lifted with a big crane to change the position of the conveyor. system runs more hours. The extendable shiftable conveyors give maximum flexibility for ash mound construction to the full height over the entire area. 5 20 7 10 21.ASH HANDLING PLANT EQUIPMENTS OF AHP: Equipments Transport Air Compressor Vacuum Pump Buffer Hopper Transport Air Line(300/350NB) Silo(2949m 3) Silo Aeration Blower Silo Vent Fan Hydro Mix Dust Conditioner Instrument Air Compressor Bottom Ash Hopper (194cuM) Coarse Ash Tank Clinker Grinder Hydro Ejector Over Flow Tank Over Flow Pump Hydrobin Settling Tank Surge Tank Sludge Pump HP Pumps LP Pumps MS Pumps Seal Water Pump Motor rating In kW 545 75 N/A N/A N/A 30 18.6 59 .8 Populatio n 2*4 4*4 4*4 2*4 5 2*2*5 2*5 3*5 3 1*4 1*4 4*4 6*4 1*4 2*4 6 2 2 2*4 6 6 3 2 11 320 75 75 45 3.5 7.5 atm 0.5 m 3 /min 28 T up to high level 55 T max. 4 2.7+0. 20 Outlet Pr. 4 atm N/A 7 kg/cm 2 N/A N/A Inlet Pr.5 125 N/A N/A 7.1.5 . (40T avg.7=1.5 Capacity 159/147 m 3 /min 46.) 2500 T 12 m 3 /min 200 m 3 /min 200 T/hr 14 m 3 /min 128 T 38 m 3 70 T/hr 45 54 m 3 245 m 3 /hr 650 m 3 750 m 3 1500 m 3 40 400 m 3 /hr 296 m 3 /hr 296 m 3 /hr 30 Pressure In kg/cm 2 2.29 -400 mmHg 0. 4 for each unit (2 working. 2 standby) 35 m3 up to high level 1.ASH HANDLING PLANT TECHNICAL DATA OF AHP EQUIPMENT: TRANSPORT AIR COMPRESSOR: Number Make Discharge Pressure Flow Gear Box Make Ratio Motor : : : : : : : : : 8 no.. 2. 1-2-3 for unit 1&2 and 3-4-5 for unit 3&4 Silo no 3 for saleable purpose.26 kg /cm2 (For Unit# 1 & 2) 1.41 m3 (2 no below each Buffer Hopper) BAG FILTERS: Number Material Size : : : 81 in each Buffer Hopper Nomex 150 mm Diameter & 2750 mm long (each) DRY ASH SILO: Number : 5 no. New Delhi-55 2. USA Rotary Lobe Vacuum Blower 46.49 : 1 545 kW/ 6.8 m3 /min at 16 mm of Hg 1057 75 kW / 415 V BUFFER HOPPER: Number Capacity Volume of air lock tank : : : 16 no. Chinchwad.6 kV VACUUM PUMPS: Number Make Type Inlet Volume Rpm Motor : : : : : : 16 no. 2 standby) Roots Division Dressers Industries Inc.97 kg /cm2 (For Unit# 3 & 4) 159 N m3 /min (For Unit# 1 & 2) 147 N m3 /min (For Unit# 3 & 4) David Brown Greeves Ltd. 2 for each units Khosla-Crepelle. 4 for each unit (2 working. Pune. 60 . 3 for each silo (2 working.5 kW. Set of 2 blowers in series per silo (5 sets working. (1 working. 1 set standby for all the Pressure Stage-I : Stage-II : Motor : These blowers supply aeration air to silo by which dry ash slides towards inlet gate of Hydro Mix Dust Conditioners (HMDC). 1 standby) 200 T / hr 61 . 415 V TELESCOPIC CHUT VENT FAN: Number Motor : : 5 no. Ltd. 2no per silo. Centrifugal 12000 m3 /hr 18. SILO VENT FAN: Number Make Type Flow Rate Motor : : : : : 10 no. 1 for each silo 5.5 kW / 415 V ROTARY FEEDERS: Number Motor : : 15 no. 415 V HYDROMIX DUST CONDITIONER: Number Capacity : : 15 no.ASH HANDLING PLANT Capacity Diameter : : 2949 m3 15 m SILO AERATION BLOWER: Number silos) Make Type Capacity Rpm : : : Stage-I : Stage-II : Swam Engineering Twin Lobe Compressors 770 m3 /hr 1650 1250 7000 Mmwc 14100 Mmwc 30 kW / 415 V : 12 no.2 kW. 1 standby) Batliboi & Co. 3 for each silo 2. 0 kg /cm2 125 kW / 415 V : : 3 no. 1 for each unit Water Impounded COARSE ASH TANK: No Capacity : : 4 no. Pumps are also used for flushing of hydrobin decanters & slurry lines etc. M. 10-12 kg/cm2 Working pressure : Mix spray water pumps are used for HMDC nozzles to condition the dry ash which passes through it. (2 working. 1 standby) 14 m3 /min (each) AIR DRYING PLANT : Capacity : 1800 N m3 /hr BOTTOM ASH HOPPER: Number Type Section of Hopper Capacity Discharge Gate : : : 2 per boiler 196 m3 (128 T) 4 no per hopper : : 4 no. : : : 196 m3 /min Motor 2 pumps in service and 1 pump in standby condition. 1 for each unit 38 m3 CLINKER GRINDERS: 62 . Pressure Motor Stage-I Stage-II : : : 1. INSTRUMENT AIR COMPRESSORS: Number Flow Rate Dish.S. 415 V MIX SPRAY PUMPS: Capacity Drive Nos.5 hp.8 kg /cm2 8.ASH HANDLING PLANT Motor : 7. 5 kW / 415 V 7.. 1 standby) Indure Ltd.8 kg /cm2 45 kW / 415 V HYDROBINS: Number Capacity Top Diameter : : : 6 no. 6 no per unit (4 for Bottom Ash Hopper. Pressure Motor : : : : : 8 no. 4 for each unit (2 running.52 : 1 960 rpm Gear Box Ratio : Fluid Coupling : HYDRO EJECTORS (JET PUMP): Number Make Size Nozzle size Capacity Head Flow : : : : : : : 24 no.ASH HANDLING PLANT Number Type Make Capacity Motor : : : : : 16 no. 2 per unit (1 working. 3 for unit 1 & 2 and 3 for unit 3 & 4 650 T 10. 245 m3 /hr 2. 2 standby) Double roll Indure 70 T / hr 7. 2 for Coarse Ash Tank) Indure 152 mm*100 mm*150 mm (Inlet*Throat*outlet) 44 mm 70 T /hr 208 MWC 400 m3 OVER FLOW TANK: Capacity : 54 m3 OVERFLOW PUMP: Number Make Capacity Dish. U. Sahibabad.6 m 2*4 kW / 415 V / Opposite direction Vibrofeeder Motor: 63 .P. 3 for unit 3&4) Becon Weir Ltd. Single Stage. Pressure Motor : : : : : 8 no.0 kg /cm2 11 kW/ 415 V HIGH PRESSURE WATER PUMP: Number Make Type Capacity Head Motor : : : : : : 6 no (3 for unit 1 & 2.7 Litres / sec 63 Mwc 64 . 3) 112.6 kV Number of Stages : LOW PRESSURE WATER PUMP: Number Make Type Capacity Head : : : : : 6 no (3 for unit 1 & 2. 2. 2. 3 for unit 3&4) Becon Weir Ltd. 6) 208 Mwc (For Hp-1. Single Suction Centrifugal 7 110 Litres / sec (For Hp-1.5 kg /cm2 50 m3 /hr 3. 6) 320 kW / 6. 3) 176 Mwc (For Hp-4.02 m SURGE TANK: Number Capacity Top Diameter : : : 2 no (one for unit 1&2 and one for unit 3&4) 1500 m3 23 m SLUDGE PUMPS: Number Seal Water Pr. 2 for each Settling tank & Surge tank (1 working. Capacity Dish. 5. 5.ASH HANDLING PLANT SETTLING TANK: Number Capacity Top Diameter : : : 2 no (one for unit 1&2 and one for unit 3&4) 750 m3 20. 1 standby) 3. Double Suction Centrifugal 81. Multi Stage.78 Litres / sec (For Hp-4. 85 65 . Besides the long travel at approx.ASH HANDLING PLANT Motor : 75 KW / 415 V MIXER SPRAY WATER PUMP: Number Make Type Capacity Head Motor : : : : : : 3 no Becon Weir Ltd.9 UNIT -IV 2 * 0.0 meters/minute. Fnd-9 Multi Stage Centrifugal Type 7 8. The magnificence of this wonder machine can be judged by the fact that it is guaranteed to give ash output of 2000 T /hr. 6.3 Litres / sec 216 Mwc 45 KW / 415 V Number of Stages : BOOM SPREADER MACHINE (SP-1): The crawler mounted spreader machine forms the backbone of the dry ash handling system at NTPC Dadri. the spreader discharge boom can slew with the machine super structure within the angle range of + 145 degree and be luffed in the vertical plane from 3 to 16 degrees making it possible to attain maximum dumping height of 15.00 lacs T. 1 standby) Becon Weir Ltd. It has already dumped approx. of ash on the ash mound during last five years operation. the 300 MT machine while traveling on the crawler pads spreads and feeds ash to the permanent ash mound. FLY ASH TRANSPORT LINE: UNIT -I LENGTH OF PRESSURE 2 * 1 km UNIT -II 2 * 1.1 UNIT -III 2 * 0. 68.5 meter.7 Litres / sec 63 Mwc 75 kW / 415 V Number of Stages : SEAL WATER PUMP: No Make Model Type Capacity Head Motor : : : : : : : 2 no. Multi Stage. As the name suggests. Double Suction Centrifugal 2 81. (1 working. C.C.C.I.I. LINE a) A.I. LINE a) A. C. I (250 NB) LENGTH OF APH Vac. (2OO NB) b) A.ASH HANDLING PLANT LINE a) A. (2OO NB) b) A. C. (3OO NB ) 50% b) CAST BASALT(350 NB) 50% LENGTH OF ESP Vac. I (250 NB) 50 meter 10 meter 80 meter 10 meter km km km 50 meter 10 meter 80 meter 10 meter 50 meter 10 meter 80 meter 10 meter 50 meter 10 meter 80 meter 10 meter 66 . It is used for LIST OF MOBILE EQUIPMENTS: 1. 12. 8. equipment which are being used for the construction of ash mound and spreading of ash stacked by spreader system.ASH HANDLING PLANT INTRODUCTION OF MOBILE EQUIPMENTS: Mobile equipment stated there are the. Vibratory rollers are used for compaction after final leveling is completed pipe layer is used for shifting of field conveyor. 11. Capacity tank. 3 Nos. Articulated Dump Truck. are used for lifting & shifting of ash from one place to an other place for land filling. 2 Nos. 1 No. 3 Nos. Bulldozers also work as compactors because of the weight. 2 Nos. 5. Other equipment such as Pay Loader. 7. DOZER D-355 DOZERS D-155 DOZERS D-50 VIBRATORY ROLLER PAY LOADER MOTOR GRADER EXCAVATOR ARTICULATED DUMP TRUCK BOWSER DUMPER PIPE LAYER TRACTOR CRANE : : : : : : : : : : : : : 1 No. Bowsers are water sprinklers with 5 Kl. 10. 2 Nos. water spray on ash mound and nearby areas. 6. Bulldozer/zero is being used for spreading of stacked ash on ash mound. Moor grader is used for leveling of ash. 3. 1 No. 1 No. 13. 2 Nos. 67 . 9. 1 No. 2 Nos. 4. Excavator. 2. 1 No. Tata Dumper etc. leveling and ramping the ash deposited by the boom spreader. One small dozer D-50 is being used in temporary stock yard for helping the reclaimer to collect the ash near reclaimer bucket. high and will not be level nor to the specific angle required. Ditch and drain cleaning was also a major problem and it was not possible to clean them manually. Operation of dozers reduces the boom spreader movement particularly when it reaches at limit. EXCAVATOR: Requirement of Excavator has been felt for making peripheral ditch around ash mound & drains around ash mound. The additional work which has a major role is lifting & shifting of ash from ash mound area to other places. in the excavator plays a major role as filling of dumpers are easy with the help of excavator. Pay Loader is used to lift and load ash in dumpers bucket for transportation of ash from ash mound to other low laying areas or to fill the rain cuts.ASH HANDLING PLANT REQUIREMENT & OPERATION OF VARIOUS MOBILE EQUIPMENTS: DOZER: The dozers are required for spreading. The bulldozers provide trimming. pay loader is also used to remove the mud and silt taken out from ditches by other machines. As discharge from the boom spreader generally falls in a pile 15 M. PAY LOADER: Requirement of Pay Loader is not connected with ash mound construction. This is operated after leveling of ash on mound surface and after reaching to required level at final stage. This small dozer is also used for making ditch slopes and lagoon area for filter bed preparation. Generally two D-155 dozers or one D-155 and one D-355 dozers are used for this purpose. Even though we 68 . This is used for compacting ash throughout the ash mound on place surface on top of mound and also on slopes. VIBRATORY ROLLER: Vibratory roller is basically a compactor cum roller. As before every rainy season ditch and drain cleaning was essential we preferred to purchase a excavator for this purpose. These two dozers are also used to from the graded side and face slopes to their rough profifles and any temporary ramps and accesses. This pulls field conveyor along its complete length in a step of 0. MOTOR GRADER: Motor Grader is a leveler / planner. The operation of rear engine and nozzles etc. are controlled from driver’s cabin. There bowser are also used for spraying of polymers on the ash mound finished surface to suppress dust. Bowser is consists of 5 Kl. hose recl. It is having a small blade between its front and rear tyres. With help of excavator we have reduce idle time of dumpers. PIPE LAYER: Pipe Layer is specially designed equipment for shifting of field conveyor a special attachment was fabricated and fitted on bulldozer model D-155 for this purpose. This dump truck is also used for shifting of ash from ash mound to other low laying areas for land filling purpose. valves. Bowsers are procured for this purpose. And spray nozzles. Capacity tank mounted on chasis.5 m at a time. 69 . ARTICULATED DUMP TRUCK: Articulated Dump Truck is being used to deposit ash in areas physically out of reach of the boom spreader.ASH HANDLING PLANT have one pay loader but it was not sufficient to fill the dumpers. engine driven centrifugal pump is installed on the chasis with water meter. Bowser are basically water spraying vehicle. Polymer spray on surface on mound makes a thin film of polymer on mound surface which eliminates the dust emission even in storm. It is used for final leveling of ash on mound and slopes to get the final profile. BOWSER: As water spreaying is an essential task in ash mound construction and to reduce dust emission. ASH HANDLING PLANT ASH UTILIZATION: • • • • • • • • • • • • • • OPC PPC (Portland Pozzolana Cement) Concrete Road Construction Embankments Land Development Structural Fills Lightweight Aggregates Lime-Fly Ash Bricks Clay-Fly Ash Bricks Insulating bricks Mineral Wool Cenospheres Colored Bricks 70 .