Improvements relating to low temperature carbonisation

摘要

A combined carbonizing, lime-burning, and electric furnace plant for obtaining calcium carbide, comprises a number of retorts charged with coal and limestone, and enclosed in a water jacket from which steam is obtained for generating electric current which is used in a furnace to which powdered lime and coke are fed from the retorts for the production o calcium carbide, the electrode for the furnace being made in a central retort. A boiler 1 is provided with corrugated tubes 2 into which retorts 5, 6 and an electrode chamber 4 are inserted. Gas from pipe 57 and air from openings 56, Fig. 6, supply heat to the flues 3, the retort door 58 being held in place by a pivoted arm 61. Coal and limestone in retorts 5, 6 are converted into coke and lime which are discharged into hoppers 15, 16 feeding crushing rollers N, Fig. 2, through which are circulated feed water for the boiler. The powdered coke and lime are air borne through duct S to a container, the larger particles falling on to a conveyer 23. The coke and lime powder are then fed through tubes 24, 28, in a water heater 25, and pass into an electric furnace 65 into which dips the electrode 7 which is fed downwardly by endless band grips 62. The hot gases evolved from the furnace pass upwardly through a perforated partition 33 and tubes 26 in the water heater 25, and are drawn off through pipe 66 for recovery of byeproducts before being burned in the tubes within the boiler 1. A plug 40, on withdrawal, allows the molten carbide to flow on to a cooled circular table 46 on which it is divided into sections by a cutter 44. A turbo-generator driven by the steam raised in the boiler provides a supply of electric current to sliding contacts 70. The furnace pan 29 is carried on arms 34 on a shaft 35 which is raised or lowered by a piston 36 in a hydraulic cylinder 37. Two pans are arranged on the same shaft at an angle so that when one is in use the other may be cleaned. The electrode 7 is made by heating a compacted mixture of powdered anthracite and coke in the central retort 4, and the current passes to a hollow electrode 32 through which the molten carbide flows. The feed water for the water space 25 is heated by a water jacket on the electric furnace, an inlet 68 being connected to a water jacket on the carbide cutter.