Improvements in or relating to processes of and apparatus for producing oil and other products from bituminous materials such as shales, schists, coal or the like

摘要

224,907. Gr÷ndal, G., and Carlson, L. Nov. 17, 1923, [Convention date]. Tunnel furnaces.-A tunnel furnace used in coking and carbonizing is heated by flues d, e and i, hot gases from two fireplaces passing into flues d, e respectively and being then conveyed by channel h to flue i and then to the chimney.