1286a.    GUMZ, W.  [Present Status and Future Possibilities in Gasification Processes.]  Gas- u. Wasserfach, vol. 88, 1947, pp. 129-136; Chem. Abs., vol. 42, 1948, p. 4,729.

         Trend of gas production is in the direction of complete gasification with the use of noncoking coals.  Water-gas generators are commonly used for synthesis-gas production; the use of O₂ is advantageous when this can be generated at a low price.  A greatly expanded use of producer gas is seen particularly in steel works owing to the tendency to sell coke-oven gas to super-gas schemes.  The Flesch-Winkler gas producer serves as a transition stage between the grate-type producer and the powdered-coal gas producers.  In this generator a 1-m. layer of fine fuel is held on a grate by an air pressure of about 4 mm. H₂O column.  This is gasified for 10-15 min. until a slag layer is formed, which is caused to sink to the grate by introducing steam; this slag is then removed by means of a H₂O-cooled stirring arm.  The slag removal period requires 1-3 min., which is followed by a purge of 1 min. after which fresh fuel is introduced and gasification continued.  Low-grade high-ash fuels are used.  The slagging-type producer offers considerable promise for low-grade fuels, especially when combined with metal recovery.  A dry air blast is ordinarily used, but this producer can be operated with 2 stages, the upper using saturated air and the lower dry air.