Lamont Boiler is the first forced convection boiler.It is a high pressure water tube, forced circulation externally fired. boiler. It was name Lamont Boiler because it was introduced by Douglas La-Mont in the year 1925.
In lamont boiler, external water tube pump is used to circulate water within water tubes of the boiler. So, pressure of water in the tubes is more as compared with pressure of water in natural circulation boiler.
Lamont Boiler is mainly used in power plant industries to generate electricity.
Parts Of Lamont Boiler:
These are the main parts of Lamont Boiler:
1) Feed Pump:
Feed Pump supply water into the boiler from hot well.
Economizer is used to increase the temperature of feed water to some extent.
3) Centrifugal Pump:
Centrifugal pump is used to circulate water inside the Lamont Boiler as it is a forced circulation boiler. The pump is driven by a steam turbine and the steam for this turbine is taken by the boiler. This boiler uses its own steam to drive its pump that circulate water in it.
4) Steam Seperating Drum:
Role of this part of Lamont Boiler is indicated by its name. It seperates steam from water.
5) Super Heater:
Steam generated from the evaporator is saturated steam and if used in steam turbine can cause corrosion on the turbine. So the saturated steam is sent to the super heater where it converts into superheated steam and this superheated steam is sent to turbine.
6) Radiant Evaporator:
Radiant Evaporator heats the water with help of radiation. It is located near furnace.
7) Convective Evaporator:
Convective Evaporator is located above the Radiant Evaporator. It heats the water by convection process.
Air preheater is present near the top of the Lamont Boiler. Its main function is to improve thermal efficiency of boiler by preheating the air from coming from the blower and this preheated air is sent to the furnace.
It blows the air into the air preheater which further is sent to furnace to increase the efficency of boiler.
Construction of Lamont Boiler:
- In lamont boiler, air blower is connected to the air preheater and supply air to this. This air preheater is connected to the furnace.
- The water feed pump is connected to the economizer which preheats the water an this economizer is connected to steam seperator drum.
- The Steam seperator drum is connected to the radiant evaporator which is located near combustion chamber and this radiant evaporator is connected to convective evaporator which is present above it.
- The steam seperator drum is also connected to the super heater which further heats the air to desired level and then transfer the steam to turine to produce electricity.
Working Of Lamont Boiler:
- At first, the air blower will blow air to the air preheater where air is preheated and sent to the furnace to increase the thermal efficiency of the boiler.
- On the otherside, the water feed pump circulates the water into the economizer of the boiler. The economizer heat the water to some extent and this water is sent to the steam seperator drum.
- After the steam seperator drum, this water is forced circulated through the radiant evaporator by the external centrifugal pump which is driven by steam turbine. Radiant evaporator heats the water and convert some portion of water into steam.
- Water and steam mixture from the radiant evaporator is sent to convective evaporator. In convective evaporator, water is further heated and most of the water converts into saturated steam. Water passes from these two evaporators 10 – 15 times until almost all water converts into saturated steam.
- The mixture of saturated steam and water is then sent to steam seperator drum to seperate the steam from water. In the steam seperator drum, the steam is collected at upeer portion of the drum and the remaining water settles down.
- This saturated steam present in steam seperator drum cannot be sent to the turbine directly as it will cause corrosion in the turbine. So, the saturated steam is passed through superheater where the temperature of steam is increased to desired level and saturated steam converts into superheated steam.
- After that this superheated steam is either sent to the steam collecting drum or sent to the turbine to produce electricity.
- Also, air from the air preheater reaches the furnace where the fuel burn. The flue gases from the furnace first heat the evaporator and then passes by the the super heater. These gas after passing through the superheater reaches the air preheater and are used to preheat the air before reahing frunace.
Advantages of Lamont Boiler:
1) Lamont Boiler has very flexible and simple design.
2) It has high heat transfer rate.
3) This boiler has high heat transfer rate.
4) It has very high steam generating capacity (about 50 tonnes per hour ).