GB191827A - Improvements in the manufacture of electrodes - Google Patents

Abstract

191,827. Illingworth, S. R. Oct. 18, 1921. Carbon.-Electrodes, particularly those for use in furnaces, are manufactured from the substances varying from smokeless fuel to true coke set out below, by compressing one or other of them, heating it at least 50‹ to 100‹ C. above the temperature of decomposition of rasinic matter in the compressed substance and preferably to 600‹ C., and then impregnating it with pitch rendered liquid by heat and corbonizing at 800‹ to 1000‹ C. or upwards. The substances used are (a) coals preheated below 600‹ C. as described in Specifications 164,104 and 175,888, [Class 55 (i), Coking &c.], or coals preheated above 600‹ C. as described in Specification 186,384, [Class 55 (i), Coking &c.], (b) coals oxidized as described in Specification 186,085, [Class 55 (i), Coking &c.], (c) coals blended as described in Specification 186,085, [Class 55 (i), Coking &c.], (d) coals of low volatile content as described in Specification 187,328, [Class 55 (i), Coking &c.], (e) carbonized caking coals of high oxygen content (over 8 per cent) which when carbonized at temperatures of 50‹ to 100‹ C. or higher above the temperature of decomposition give a hard fuel or dense structure, and (f) carbonized bituminous coals whose resinic content is reduced below 5 per cent and which produce a coherent product when carbonized at 500‹ C. One of the substances above is stamped into a mould a, Fig. 1, provided with a perforated cover c and wedges g, h for moving a side plate e. The mould is placed in the oven i, Fig. 3, and heated to the desired temperature after which it is removed through the door j and the wedge h is driven in to hold the mass in place. The mould is then lowered into the tank k which is evacuated through the pipe r. When the temperature of the tank has fallen to 250‹ C. for half an hour, preferably by waste flue gases from the oven i, after which excess pitch is allowed to run back to the tank o through the pipe q. The mould is then placed in an oven of the same type as the oven i and situated on the opposite side of the tank k and is heated therein to 800‹ C. or upwards after which it is placed in a cooling chamber filled with an inert gas. For large electrodes the tank k may be under pressure. The ovens have condensing appliances to recover bye-products. Tar or other bitumen or resin like product may be used in place of pitch.