GB393305A - Improvements in or relating to rotary retorts, furnaces and similar apparatus - Google Patents

Abstract

393,305. Rotary furnaces or retorts. BRITISH COAL REFINING PROCESSES, Ltd., 3, Central Buildings, Westminster, and SALERNI, P. M., 23, Carlton House Terrace, St. James's, London. Sept. 17, 1931, Nos. 7101/33 (divided on 393,297), 26215/31, 28145/31, 33190/31, 1648/32, 1921/32, and 4739/32. [Classes 51 (ii) and 55 (i).] An externally heated rotary retort comprises an inner element formed by walls 2, 3 containing an annular space 4 through which heating gases pass, the inner element being supported by an outer element or shell 1 to which it is slidingly connected and by which it is rotated, a gas being passed in the space 14 between the elements to prevent heating of the outer shell 1. This retort is suitable for carrying out the process described in Specification 393,297. The inner drum 2 which may be made of a series of welded cylindrical sections, is connected to the outer drum 3 by resilient members 6 secured to rings welded to the sections 2, 3 which may move relatively in a radial direction. To compensate for longitudinal expansion the plates 3 are corrugated at 7. The members 6 have keyways 9 in which slide pins 10 carried by the shell 1. Insulating jackets 13, 8 are provided on the shell 1, and inner element respectively. Cool gas, such as spent flue gas, is passed through the space 14 to insulate the shell 1 from the heat of the heating space 4. The rotary cylinder is mounted on rollers, and its ends extend into stationary heads B, C, gaseous means being provided as described in Specification 393,306 to prevent escape or entry of heating or distillation gases. These means comprise the use of maze plates 27 adjacent the heating passage, plates 28 adjacent the cool gas passage, and plates at 29, 30 to prevent escape of distillates or heating gases, or the mixing of these gases. The heads B, C provide passages for the entry and exit of the heating gases in the annular space 4, and of the cooling gases in the space 14, and are spring-mounted. Scraping means are provided of the kind described in Specification 393,303, comprising a flexible support 44 from which are suspended scrapers 43. The temperature of the inner element is registered by mounting on the outer shell a split ring 45, Fig. 9, connected with the inner element by radial pins 46, a scale 48 being made on one end of the ring, and a pointer provided. On expansion of the inner element due to heat, the ends of the ring are forced apart, and a measure of the temperature obtained. A thermostat is used to regulate the supply of air and fuel gas to the combustion chamber from which the hot gases are supplied to the retort. The coke ovoids are delivered to a gastight shoot leading to a conveyer 49 on to which the raw coal is fed, so that the coal covers the coke, and is thus preheated. The coke powder from a crusher, and the preheated comminuted coal, are mixed in a drum into which hot heavy oils from the process are introduced, and the blend is fed to the retort.