Abstract: A reactor for gasifying solid fuels, particularly coal, comprises with the fixed bed of fuel at least one stirring arm, which is rotatable about a vertical axis and is approximately triangular in cross-section. The forward knife edge and the rear crushing edge of the stirring arm are provided with replaceable armoring. The armoring at the knife edge consists of a plurality of armoring elements (7), which are approximately V-shaped in cross-section and are arranged one beside the other so as to define an expansion joint. The armoring at the crushing edge consists also of a plurality of elements (10), which are mounted on the stirring arm so as to be movable at ambient temperature.

Abstract: A process for gasifying coal comprising supplying to an upper portion of an entrained flow gasifier a coal powder having a particle size of 100 .mu.m or less whereby gasification is conducted at 900.degree. C. or higher in the absence of oxygen, supplying a coal powder including coarser particles and oxygen in an amount from that necessary for complete combustion of coal to a half of said amount to a lower portion of the gasifier whereby gasification is conducted at a melting point of coal ash or higher, and leading the gases produced at the lower portion of the gasifier directly to the upper portion of the gasifier, does not require recycle of char to the gasifier and gives a high gasification efficiency by passing coal powder through the gasifier only one time.

Abstract: The invention concerns a process for the preparation of a combustible gaseous mixture or product gas from a nongaseous fuel in which a gasifier is used provided with a rotatably driven cup-shaped support grate 3. A granular or pulverized refractory auxiliary material and fuel are continuously fed to the inner side of said grate, a gasification medium or process gas being fed to the outer side of the grate, whereupon the resulting product gas and the exhausted auxiliary material with ash from the fuel, are discharged separately. According to the invention the fuel consists, at least partly, of a residual oil previously fed into the fuel chamber 14, 15.

Abstract: For the chemical cleaning of cooled waveguides, in particular water-cooled waveguides of electric machines and apparatus, whose cooling cycle is maintained by a feed pump and comprises an ion exchanger in a closable bypass, alternately a complexing agent is added into the cooling cycle with the bypass closed and thereafter a purification of the cooling water via the ion exchanger is effected with the bypass open. The preferred complexing agent is a chelate former or one of the salts thereof. In addition to the complexing agent, an oxidant, in particular hydrogen peroxide or oxygen gas, may be added in at least one passage cycle.