Heat exchanger attached to double walled chimney - has spiral water tubes with water heated in counter flow to hot gases

摘要

The heat recuperator is for a boiler which can also be the chimney and is double-walled. The hot gases travel up inside the inner wall and also through the annular space between the inner and outer walls. Water passes through the inner wall in counter flow to the hot gases passing upwards inside it. The outer wall consists of a sheet, onto the outside of which is welded a coil made of sheeting suitably formed. Thus a double coil can be formed by welding on a continuous U section spiral, and bridging the space between two coils with a welded-on strip. Water can also be passed through these coils, either in counter-flow to the hot gases, or in the same direction. Suitable water feed and return pipes are fitted top and bottom.