Boiler with hot water unit above combustion unit - has restricted connection between units and burner at rear of bottom

摘要

A boiler producing hot water and steam, with natural circulation or under pressure, has the hot water unit mounted above the combustion unit with a connection of restricted size between them. The connection may be made simply with an asbestos string joint or similar so that they are detachable. The combustion gases passing up through the joint to a tube bundle in the top unit. The burner is positioned near the bottom at the rear of the lower unit, or, in an alternative design, near the top at the rear of the lower unit, inside the combustion chamber.