Explain the working of Cochran boiler with neat sketch
The Cochran boiler is vertical, multi-tube boiler generally used for small capacity steam
generation. Cochran boilers are made in different sizes of evaporative capacities ranging
starting from 150 to 3000 kg/hr. and working pressure up to 15 bar.
Working:
1) First, the coal is fed to grate via a fire hole for a burn.
2) The ash formed in burning is collected in ash-pit below the grate and it removes
manually.
3) The hot gases from the grate pass through the combustion chamber to horizontal fire
tubes and transfer the heat to water by convection.
4) Exhaust gases out from fire tubes pass through smokebox and exhaust to the
atmosphere via a chimney.
5) There is a door in the smokebox for cleaning the fire tunes and smokebox. The
Cochran boiler has a working pressure of 6.5 bar and a steam capacity of 3500 kg/hr
