Today we will learn about Babcock and Wilcox
boiler. Babcock and Wilcox boiler is a natural circulation, externally fired medium
pressure, stationary horizontal water tube boiler in which water is flow in the
inclined tubes. The furnace is located outside of the drum.
This boiler is invented by Stephen Wilcox and George
Herman Babcock in the year 1967. So this is named as Babcock and Wilcox.
Also Read : Types of Boilers
Also Read : Lamont Boiler : Main Parts & Working
Also Read : Types of Boilers
Also Read : Lamont Boiler : Main Parts & Working
Babcock and Wilcox boiler:
Main Parts:
Babcock and Wilcox is a stationary water tube boiler.
It has inclined tubes which are inclined at 10 to 15 degree, which are inclined
to maintain natural circulation of water from drum to tubes and steam from
tubes to drum. The main parts of this boiler are as follow.
1. Steam separator drum:
This
drum is situated upside of the boiler. It is larger diameter drum in which
water and steam placed together. The one half of the drum is filled with water
and the other half is remaining for steam.
2. Water tubes:
Water
tubes are situated bottom side of the drum. Water flows from the drum to the
tubes.
3. Uptake header:
Steam
separator drum and water tubes are connected by the two tubes. One is known as
uptake header and the other one is known as down take header. The steam from
the water tubes to the drum flow by the uptake header.
4. Down take header:
The
water flows form the drum to the water tubes through down take header. When the
steam flows by uptake header to the drum, at the same time water flows from
drum to the water tubes by down take header which maintains the flow of water.
5. Grate:
The
place in the furnace, where the fuel is placed and burn known as grate.
6. Furnace:
The
furnace is the place where the fuel burns. This is situated at the down side of
the water tubes. When the fuel burns, the flue gases generate. This gases flow
upper side and passes through water tube, which heat the water and convert it
into steam.
7. Super heater:
Super
heater is situated upper side of the water tube. One end of super heater is
connected to the drum and other end is for process work. Steam flows from the
drum to the super heater, where it heated by the flue gases and send for the
process work.
8. Baffles:
Baffles
are provided between the water tubes. The main function of baffles is to divert
the flue gases, so it flows more than one time through the tube and more heat
is transfer.
Other mounting like safety valve, blow off valve,
fuel door, inspection door, mud box, feed valve, stop valve, pressure gauge etc.
are also provided for safely working of boiler.
Working:
Now we discuss about working of Babcock and Wilcox
boiler. This is a high pressure, natural circulate, water tube boiler. The
working of this boiler is as follow.
* First water is filled in the water drum through feed
pump. The drum is half filled with water and the upper half is for steam.
First flue is fired at the grate.
* The flue gases generate by burning of fuel. These gases
start flowing from one end to another end of boiler.
* The flue gases passes by the water tubes and exchange
heat with water. The baffles are provided in the way, which deflects the flue
gases before escaping from the chimney. Due to this deflection, the flue gases
pass more than one time through water tubes, which cause more heat transfer.
* The water flows from the drum to the water tube
through down take header.
* The water tube nearer to the furnace heated more
than the other, so the density of water decrease in this tube which causes the
flow of steam from tube to drum through
uptake header. At the same time the water from the drum enters into the tubes
through down take header.
* The circulation of water from drum to tubes and
again tubes to drum is natural, due to density difference.
* The steam separates in the drum at the upper half.
This is saturated steam. This steam sends to the super heater through steam
pipe. The steam is heated again by the flue gases in the super heater and taken
out for process work.
* The flue gases send to the atmosphere from the super
heater.
* This process repeat until sufficient amount of steam generates. This
boiler can generate 20 ton steam per hour.
For better understanding of working of Babcock and Wilcox boiler watch the video.
For better understanding of working of Babcock and Wilcox boiler watch the video.
Advantages:
1. The steam generation rate is higher about 20 ton
per hour at pressure 10 to 20 bars.
2. The tubes can be replaced easily.
3. The boiler can expand and contract freely.
4. It is easy to repair maintenance and cleaning.
5. It drought loss is low compared to other boiler.
6. The overall efficiency of this boiler is high.
Today we have discussed about Babcock and Wilcox
boiler. If you have any query, asks by commenting.