What are the methods used in ash handling system?

What are the methods used in ash handling system?

Some of the techniques being used for ash handling are given below.

• High concentration slurry disposal (HCSD) ...
• Dry fly ash disposal system. ...
• Dry bottom ash system. ...
• O&M issues. ...
• The way forward.

Why and how ash handling is done?

In thermal power plants, an ash handling system is used to collect and dispose off discharged ash, once it has been cooled down to a manageable temperature, which is then used in various industries like construction, cement plants, and other allied industries.

How ash is handled in the power plant?

Mechanical plant electrical services Ash from the boiler is collected in a hopper directly below the furnace, whence it is removed by high pressure water jets and discharged, via sluiceways, into ash crushers.

How do you handle fly ash?

1 Moisture must be avoided in a dry handling system, since many fly ashes are hygroscopic and will react with water. If moisture is inadvertently added, caking, agglomeration and build-up can occur. Fly ashes are well known for their cementitious properties and are often used in low strength concrete mixes.

How is fly ash collected?

Fly ash is captured from the flue gases using electrostatic precipitators (ESP) or in filter fabric collectors, commonly referred to as baghouses. The physical and chemical characteristics of fly ash vary among combustion methods, coal source, and particle shape.

What is bottom ash used for?

Embankment or Backfill Material (Mainly Bottom Ash) Bottom ash and ponded ash have been used as structural fill materials for the construction of highway embankments and/or the backfilling of abutments, retaining walls, or trenches. These materials may also be used as pipe bedding in lieu of sand or pea gravel.

Why is ash handling harder than coal handling?

Ash produced is about 10 to 20% of the total coal burnt in the furnace. . Handling of ash is a problem because ash coming out of the furnace is too hot, it is dusty and irritating to handle and is accompanied by some poisonous gases. ... (iv) It produces poisonous gases. (v) It has corrosive action.

Why is it important to prefer ash handling?

Why is it important to prefer ash handling systems? Explanation: Considering the large coal burning capacity plant of modern times, the amount of ash produced when the coal is burnt is in thousands of tones. It could have an effect on other subjects too if the proper ash handling methods are not followed.

How many types of ash handling systems are there?

Ash handling system are generally divided into three types fly ash handling system, bottom ash handling system and ash slurry disposal system.

How do you prevent fly ash?

To prevent the ash from completely escaping when the coal is burned, electrostatic precipitators are used to collect the fly ash. Additionally, other stack filtration devices such as baghouses and scrubbers are used to reduce the emission of fly ash.

Which is the best handling system for Ash?

Wet bottom ash material handling systems and surface impoundments are currently regarded as the industry standard and are the most commonly used method in the coal-fired power industry around the world.

What are the rules for coal ash disposal?

To address the risks from improper disposal and discharge of coal ash, EPA has established national rules for coal ash disposal and is strengthening existing controls on water discharges. For more information, visit the following Web pages.

What happens to the ash when you burn coal?

The melting ash engulfs the unburnt coal particles and forms a solidified mass which is known as clinker. It is formed while burning coal containing ash which has low fusion temperature. Weathering of coal: All coals tend to combine with oxygen and slow oxidation takes place. This process of oxidation without burning is called weathering of coal.

How is Ash handled in an ash conveyor?

The ash that reaches the base of the submerged upper trough of the conveyor is scraped along an abrasion resistant replaceable liner on the floor by the flight bars, which are spaced four feet apart. At the end of the conveyor’s horizontal section, flight bars turn through the incline angle (nominally 35 degrees) and begin to rise out of the water.