Vertical Multi Tubular Boiler (COCHRAN BOILER)

Vertical Multi Tubular Boiler Points : Vertical Multi Tubular Boiler (COCHRAN BOILER), Definition There are various designs of vertical Multi Tubular boilers. A Cochran boiler is considered to be one of the most efficient type of such boilers. It is an improved type of simple vertical boiler. This boiler consists of an external cylindrical shell and a fire box as shown. (a) & (b). The shell and fire box are both hemispherical. The hemispherical crown of the boiler shell gives maximum space and strength to withstand the pressure of steam inside the boiler. The hemispherical crown of the fire box is also advantageous for resisting intense heat. The fire box and the combustion chamber is connected through a short pipe. The flue gases from the combustion chamber flow to the smoke box through a number of smoke tubes. These tubes generally have 62.5 mm external diameter and are 165 in number. The gases from the smoke box pass to the atmosphere through a chimney. The combustion chamber is lined with fire bricks, on the shell side. A manhole near the top of the crown on the shell is provided for cleaning.
At the bottom of the firebox, there is a great (in case of coal firing) and the coal is fed through the fire hole. If the boiler is used for oil firing, no grate is provided, but the bottom of the firebox is lined with firebricks. The oil burner is fitted at the fire hole.