What is meant by Stoker?
(Entry 1 of 2) 1 : one employed to tend a furnace and supply it with fuel specifically : one that tends a marine steam boiler. 2 : a machine for feeding a fire.
What can you say about Stoker?
Stoker, machine for feeding coal or other solid fuel into a furnace, usually supporting the fuel during combustion. A good stoker also supplies air for combustion and regulates the rate of burning and, in large installations, disposes of the ashes.
How does a stoker work?
A mechanical stoker is a mechanical system that feeds solid fuel like coal, coke or anthracite into the furnace of a steam boiler. The under feeder pushes fresh coal into the bottom of the furnace and then advances it upwards so that it mixes with the burning coal above.
What does Stoker mean in engine?
1. One who is employed to feed fuel to and tend a furnace, as on a steam locomotive or a steamship. 2. A mechanical device for feeding coal to a furnace.
What is it called when someone follows you around?
When you play tag and the person who’s “it” runs behind you as you dodge around trees, that person is a follower. The Old English root is folgere, “servant or disciple,” from folgian, “follow, accompany, or pursue.” Definitions of follower.
What is stoker firing?
Mechanical Stoker Firing. When fuel i.e. coal is put into the steam boiler furnace by means of a mechanical stoker, the firing of boiler method is referred as mechanical stoker firing. There are mainly two types of mechanical stoker firing systems.
What are the two types of stoker fired boiler?
The main types of stokers are:
- Chain-grate or travelling-grate stoker.
- Spreader stoker boiler.
Why is coal pulverized?
Pulverized coal firing ensures complete combustion of coal, thus ensuring higher efficiency of steam generators. It is predominantly adopted in large coal-fired utility boilers. The finer the grinding of coal, the more efficient its combustion.
What is Travelling grate?
The traveling grate is comprised of chain that carries the pellets like a conveyor. The difference is that the grate chain allows air to pass through it. The grate chain travels flat and strait. There are several compartments the pellets are exposed to different heat.
What is traveling grate boiler?
Uttam’s Travelling Grate Boilers offer high efficiency through a proven design that ensures complete combustion through high turbulence and thorough mixing of volatile gasses. Continuous ash discharge provides for higher productivity and lower downtime.
What is grate area in boiler?
A furnace grate is provided in a steam boiler furnace for supporting the solid fuel in the furnace. Grate is so designed that it can also allow air to admit air in the solid fuel for combustion.
What is overfeed stoker?
Overfeed stoker means a boiler design that employs a moving grate assembly where the coal is fed into a hopper and then onto a continuous grate that conveys the coal into the furnace. As coal moves through the furnace, it passes over several air zones for staged burning.
Which of the following is underfeed stoker?
A mechanical stoker suitable for small boilers, such as the vertical, water-tube, and locomotive types. Coal is conveyed direct from a bunker or hopper by a feed worm, which forces the fuel up through the bottom of the retort in which it is burned.
What is pulverized coal?
Pulverized coal is made from coal as the coals are crushed between cylindrical rollers and then it is air heated at about 340∘C. After that the pulverized coal is directly blown into the burner as a fuel. Pulverized coal is mainly used because it is fine enough that its combustion rate is very high.
What is the difference between overfeed and underfeed stoker?
The principal difference between overfeed stoker and underfeed stoker is in the entry of coal. Overfeed stoker is the type of stoker in which the coal is fed from the top and air is blown from below. Underfeed stoker is one where coal is fed from underneath and the air is fed from top.
What is the basic principle of overfeed stoker?
In case of overfeed stokers, the coal is fed on the grate above the point of air admission. Working principle : In this type of fuel firing, the primary air enters the grate from the bottom. The air passing through the grate is heated by absorbing the heat from the ash and grates itself. So, the grate is cooled.
What is the reason for using forced draft in multi retort Stoker?
Explanation: Forced draught causes rapid combustion. It is also necessary to introduce ‘over fire’ when high volatile coals are used to prevent the smoke formation. Combustion control is introduced into the stoker drive either by varying the ram stoke or by changing the rate of reciprocation.
When coal is being burnt how much of ash is formed compared to the whole amount?
2. When coal is being burnt how much % of ash is formed compared to the whole amount? Explanation: The coal available in nature already contains some percent of ash and when it is burnt. Due to its brittle nature more amount of ash is produced.
Why is mechanical handling of fuel necessary in power plant?
Mechanical Stoker Firing: Even though it is costlier, generally they are used to feed the solid fuels in small and medium size power plants, because of the following reasons: 1) Combustion is more efficient. 2) Fuel handling is automatic and combustion control is easier. 4) Low quality fuels can be successfully burnt.