Cast iron heating boiler has cooperating half shells provided with interfitting projections and recesses for providing meandering flue path

摘要

The heating boiler has a pair of cooperating half shells (1,1') fitted together side-by-side for providing a combustion chamber and a hot gas flue (4), the half shells having interfitting projections (9) and recesses (10) in the vicinity of the flue, for providing a meandering flue path, with tapering of the latter in the flow direction for matching the reduction in the hot gas volume resulting from cooling.