AFC-Holcroft patented "Lo-Dew" gas generator produces a variety of atmospheres with analyses ranging from exothermic (101/102) to endothermic (501/502). Design of this generator is based on burning a controlled ratio of gas and air in a closed chamber. The products of combustion are cooled in the same manner as in the 101 exothermic generator. A controlled amount of hydrocarbon is then added to these cooled combustion products. The resultant mixture is passed over heated nickel catalyst, as in the 302 endothermic generator, and a special endothermic atmosphere is produced by this patented process.
With a simple valve adjustment, the versatile AFC-Holcroft "Lo-Dew" generator allows heat treatments ranging from clean annealing and sintering (where a lean mixture is required); clean hardening, carbonitriding and carburizing (an intermediate mixture); to special applications requiring extremely low dew points.
The exothermic gas is a by-product of the primary heating reaction and corresponds to the vented gas from a conventional endothermic generator. A portion of this gas is available for use wherever a lean 101 type atmosphere is needed...such as purging and/or blanketing hot oil tanks, even when the generator is producing a rich finished gas.
With the growing concern for more efficient use of natural gas, the "Lo-Dew" endothermic generator offers an important advantage over the conventional type 301/302 generators. The patented "Lo-Dew" generator produces more finished atmosphere for a given gas output.