2. High Pressure Boiler:
High pressure boiler – Over 25 Kg / Cm2 or 24.50 bar ranging to 60-80 bar
high-pressure boiler is a type of boiler that operates at a pressure above 80 bars.
They are widely used in thermal power plants for the generation of power.
3. Example of High Pressure Boiler
LAMOUNT BOILER
Features:
- Forced Circulation
- Watertube type
- Steam Generated Rate = 45 to 50 tonnes/ hr
- Pressure is 120 bar
- Temperature is 500 C
4. Example of High Pressure Boiler
BENSON BOILER
Features:
- If boiler pressure is raised to critical pressure (221.2 bar) then the steam and water
will have the same density
- Steam Generated Rate = 150 tonnes/ hr
- Pressure is 500 bar
- Temperature is 650 C
5. Medium Pressure Boiler:
Medium pressure boiler – 10-25 Kg /Cm2 or 9.80 bar to 24.50 bar
What is a medium pressure boiler?
Medium pressure boilers fall in the range of 10 to 25 bar These are typically power
generating plants where process steam is required. The makeup demand is greater
in medium boiler plants due to steam consumption and loss. In either case, the
water treatment requirements can be met with basic chemicals
6. Example of Medium Pressure Boiler
As you know Lancashire boiler is a shell and tube type, heat exchanger. Which uses
natural current to flow the water inside the boiler. This boiler is more reliable and
can create a large amount of steam
Features:
- The maximum working pressure in a Lancashire boiler is 16 bar. It is used where
working pressure and power required are moderate. Its steam production rate is
9000 kg/hr or 9 tonnes Its efficiency is from 50% to 70% depending upon the type
of fuel used.
- -
7. Low Pressure boiler
. Low pressure boiler – up to 10Kg / Cm2 or 9.80 bar
Low-pressure boilers generally stay in not more than 10 bar and the temperature
is maintained under about 300 degrees F. This type of boiler is generally used in
buildings where a somewhat consistent temperature works for all spaces and no
rapid changes are required.
8. Example of Low Pressure Boiler
A Cochran Boiler has a vertical, fire tube boiler commonly used for small capacity steam
generation. It is an improved type of simple vertical boiler in order to minimize heating
surface. Total heating surface area is 10-25 times the grate area and the working
pressure is upto Kgf/cm2 and steam generating capacity from 20 Kg/hrs to 3000 Kg/hrs.
Boiler has dimensions ranging from 1 m diameter and 2 m height to 2 m diameter and 6
meter
Steam generation capacity 3000 – 4000 Kg/hr Working pressure 7 bar (max 15 bar)
Efficiency of boiler 70 to 75% Tube diameter : 6.25 cm (external diameter) No of tubes :
165 – 170 numbers Provided main hole at the top for cleaning purpose Commonly used
for small capacity steam generation Uses of Cochran boiler. The Cochran boiler was
produced by Cochran & Co. of Annan, Scotland. It is widely used in marine practice,
either fired directly by coal or oil fuels, or else used for heat recovery from the exhaust
of large diesel
