Abstract: A steam generating furnace which burns high moisture content fuel has a panel of heat absorbing tubes dividing it into two vertical interconnecting passageways: (a) a combustion chamber for burning the predried fuel and (b) a drying shaft for extracting moisture from the fuel. Wet fuel is introduced near the top of the drying shaft. As it falls it is dried by some of the hot gases diverted from the top of the combustion chamber into the top of the drying shaft. The cooling of the hot combustion gases due to evaporation of moisture from the wet fuel causes a difference in density between the gases in the two passageways, creates a natural, unidirectional circulation of part of the combustion gases from the top of the combustion chamber to the drying shaft. Predrying the wet fuel causes the fuel to burn faster and hotter thereby producing a stable and efficient combustion of the wet fuel at higher specific combustion rates.

Abstract: The housing of a smoke generator is provided with an outlet passage conducting a blower induced flow of particulate material from a hopper. An inflow of air is conducted to the blower separate from the material through a conduit extending through the hopper. The material is comminuted before entering the blower and is discharged by the blower into the outlet passage to accumulate on the upstream side of a screen which also forms a burner element activated by means of a switch to effect combustion of the accumulated material. The smoke so produced is displaced through the screen under the pressure produced in the outlet passage by the blower.

Abstract: A solid fuel burning hot water heater is described having a primary combustion chamber with a refractory material base portion which forms the locus of combustion. A water jacket defines an upright portion over the refractory base portion for receiving a charge of fuel in a generally vertical stack. The water jacket is coupled to a source of water for at least convection circulation and assists in confining the locus of solid fuel combustion to the base of the chamber. Heat exchange channels or pathways are defined around the outer periphery of the water jacket in heat exchange relationship with the water jacket for transfer of heat from the end products of combustion to the circulating water. A flue gas delay channel arrangement extends from the draft outlet at the base of the combustion chamber to the heat exchange pathways.

Abstract: A sawdust and chip burner for use with an existing furnace for heating water or a forced air system. The burner overcomes a previously known deficiency in prior burners in overcoming burn-back, the latter meaning creeping of combustion back into the stored fuel. The burn-back hazard is overcome in the present invention by the provision of double-walling of the fuel hopper adjacent the exit thereof and the supplying of cooling air through the passage formed by the double walling. In addition to preventing burn-back, the cooling air exits at a higher temperature and the thus heated air may be used to augment the heat output from the burner.

Abstract: A smoke generator and method for smoking food products such as meat, sausage and fish are provided. Smoke is produced from glowing sawdust maintained at a temperature just below the flame point in the presence of excess oxygen. The smoke produced is low in tar and carbon and the food product produced possesses outstanding smell and taste and has excellent uniformity of color.