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PRESENTATION

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The process of disposal of ashes from the The process of disposal of ashes from the power plant is called Ash Handling System. It power plant is called Ash Handling System. It includes following operations:includes following operations:

To remove the ashes from the furnace To remove the ashes from the furnace hopper.hopper.

To convey the ashes from furnace ash To convey the ashes from furnace ash hopper to a storage or fill with the help hopper to a storage or fill with the help of conveyors.of conveyors.

To dispose the ashes from the storage.To dispose the ashes from the storage. It occurred due to the use of low grade high It occurred due to the use of low grade high

ash content coals have been used in the ever ash content coals have been used in the ever increasing capacities of boiler.increasing capacities of boiler.

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1.1. Mechanical ash handling systemMechanical ash handling system2.2. Hydraulic ash handling systemHydraulic ash handling system3.3. Pneumatic ash handling systemPneumatic ash handling system4.4. Steam jet ash handling systemSteam jet ash handling system

Mechanical chain type ash handling system

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The hot ash coming out of boiler furnace is made to The hot ash coming out of boiler furnace is made to fall over the belt conveyor through a water seal. The fall over the belt conveyor through a water seal. The cooled ash falls on belt conveyor and it s carried cooled ash falls on belt conveyor and it s carried continuously to the dumping side or overhead continuously to the dumping side or overhead bunker.bunker.

This type of system is generally used in low capacity This type of system is generally used in low capacity power plant.power plant.

The life of this system is 5-10 years. The max. The life of this system is 5-10 years. The max. capacity of this system is limited to 5 tons per hour.capacity of this system is limited to 5 tons per hour.

The major advantage of this system is low power The major advantage of this system is low power consumption.consumption.

The mechanical ash handling system is produce less The mechanical ash handling system is produce less noise.noise.

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The hydraulic ash handling system carries the ash The hydraulic ash handling system carries the ash with the flow of water with high velocity through a with the flow of water with high velocity through a chanel and finally dumped to the sump.chanel and finally dumped to the sump.

This type of system is subdivided as low velocity This type of system is subdivided as low velocity system and high velocity system.system and high velocity system.

Ash from the furnace grate falls into the system of water possessing low velocity and carried to sump with water. The velocity of water in the water trough is usually between 3-5 m/sec.

The ash carrying capacity of this system is 50 tons/hr and distance covered is 500 meters.

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the hoppers below the boilers are fitted with the hoppers below the boilers are fitted with water nozzles at top and on the sides water nozzles at top and on the sides

The top nozzles quench the ash and the side The top nozzles quench the ash and the side nozzle provide the driving force to carry the ash nozzle provide the driving force to carry the ash through a trough.through a trough.

The ash carrying capacity of this system is as The ash carrying capacity of this system is as large as 120 tons/hr and the distance covered is large as 120 tons/hr and the distance covered is as large as 1000 meters.as large as 1000 meters.

1010 HIGH VELOCITY ASH HANDLING SYSTEM

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1. It is clean,dustlessand totally enclosed.

2. Its ash carrying capacity is considerably large therefore it is more suitable for large thermal power plant .

3. It can discharge the ash at a considerable distance from the power plant.

4. The unhealthy aspects of ordinary ash basement work is eliminated.

5. The whole systemic clean and healthy.

6. The important feature of this system is the absence of working parts with the ash.

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Pneumatic or vacuum extraction ash handling system

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This system has been developed for handling abrasive ash as well as dusty materials such as fly-ash and soot.

This is more suitable to the boiler plants from which ash and soot must be transported some considerable distance for final disposal.

The pneumatic ash handling system is subdivided as mechanical I.D. fan or stream jet type system or water jet ash handling system.

The mechanical exhauster is proffered where large tonnages of material are to be conveyed. the power require for mechanical exhauster is 3 Kw per ton of ash.

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The water jet exhauster may be used more economically where large quantities of water are easily and cheaply available.

The ash carrying capacity of this system varies from 5 to 30 tons per hour.

Vacuum & pressure pneumatic ash conveying system

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1. With the use if this system, all dust nuisance is eliminated in the handling lf flyash and dust.

2. The materials are conveyed in a dry state and delivered to the storage bin in the same condition.

3. The system has great flexibility and thus can be made to fit varying physical plant condition.

4. The conveyor pipeline requires little space in the boiler plant and therefore the cost per ton of ash discharged is less then the other systems.

The system suffers only from the disadvantage of wearing out the pipe line and therefore maintenance charges are high. It is more nosy.

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In this system a jet of high pressure steam is passed in the direction of ash travel through a conveying pipe in which the ash from the boiler ash hoppers is fed. the ash is deposited in the ash hopper.

1. The steam generated by the boiler is used ,therefore, it does not require any sort of auxiliary drive.

2. Ash can be removed economically by this system through a horizontal distance of 200 meters and through a vertical distance of 30 meters.

3. The capital cost of this system per ton of ash handled is less than other systems.

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1. There is a greater wear of pipes carrying the ash due to abrasive action of ash. Therefore the pipe is lined with nickel alloy.

2. The operation of the system is noisy.

3. The capacity of this system is limited to 15 tons/our therefore continuous operation of the system is necessary.

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TYPICAL ASH PICK-UP STATION

Prepared By: JIGAR MEVADA

PRIYA MISTRY

JAGJIVAN NANADVANA

HARESH MORI