Abstract: The invention as disclosed in the following specification, relates to a heat exchanger, having tubes fitted into plates, that exchange heat from a gas passing thereover to fluids passing through the tubes. The heat exchanger is particularly adaptable to boilers having fire tubes and other types of boilers wherein the heat applied to the tubes is circulated and then exhausted. Prior to exhaust, the heated gas is passed over the plates in a duct. The tubes in the plates are used to pick up the heat from the exhaust gases by means of the feed water passing through the tubes, or the tubes can be used to directly heat other fluids, such as oil and service hot water. A damper is placed over the normal exhaust gas flue in conjunction with a second damper or duct control system whereby an exhaust fan on the downstream side of the heat exchanger duct provides a constant draw to allow the boiler to operate within its normal pressure ranges.

Abstract: A continuous flow expander for expanding particulate material, more specifically for grain or cattle fodder, is provided whereby material to be expanded is transported in a substantially continuous manner through a pressurized region wherein it is heated, steamed and pressurized by a counterflow of dry steam created from available city water by a recirculating steam boiler. The material is then ejected by another flow of dry steam created from available water into a lower pressure region for expansion. Enthalpy in the ejection region is automatically maintained within a predetermined range, for grain or cattle fodder from 450 to 750 BTU per pound of moisture being ejected, regardless of the moisture content of the material, by varying steam boiler output and, if necessary, material flow rate. An expanded product requiring no further drying prior to use or storage is thereby provided with minimum energy use.