Process and apparatus for heating goods by a heated gas

摘要

To treat a material with a heated gas, the heated gas is mixed with an added gas at the point inlet. Part of the heated gas is returned as the added gas for mixing, from the zone behind the fan blower in the gas flow direction. The mixing of the heated and the added gas is spread vertically after the point inlet. The cooler gas is drawn wholly from the recirculating air. The heated gas is steam or the burner gas is at a gas or oil burner. Part of the drying air as a mixing gas is taken from the pressure chamber back into the suction chamber, to be mixed with the heated gas to be fed to the recirculating air. The warmed gas is 160-220 degrees C, the cooler gas is 80-150 degrees C and the heated gas is 2000 degrees C. The volume of the mixing gas is set to give a temperature of the mixture of heated and added gases of 300-500 degrees C (350-450 degrees C). The warmed gas fed back for mixing comprises 7-25% (10-20%) of the heated gas. An Independent claim is also included for an assembly with a mixing station (56,57) near the point inlet (53) for the heated gas. A mixing gas feed channel connects the pressure side of the fan (55) with the mixing station (56,57).