摘要 |
A pocket heat exchanger comprises an elongated combustion chamber that defines a plane passing through the combustion chamber longitudinal axis. A two-pass, three-pass, or four-pass duct system is arranged symmetrically about the plane to conduct hot products of combustion produced in the combustion chamber in parallel paths to a flue. The pocket heat exchanger is installable as a modular unit into the pocket of a recirculatory fluid system. The symmetrical design of the pocket heat exchanger assures that a stream of recirculating gas flowing past the pocket heat exchanger is heated to have a uniform temperature across its cross section. A shroud partially surrounding the combustion chamber and the duct system aids in directing the recirculating gas to thoroughly scrub the combustion chamber for maximum heat transfer to and temperature uniformity of the stream of gas. The flue for the products of combustion may pass through the stream of recirculating gas, or it may pass outside the stream of the gas.
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