During the development of a process for producing formed coke various systems were designed for accelerated heating of coal up to the temperature of its plastic state by a gaseous heat-carrier.* The systems consist of three or four identical stages. Each stage consists of a heat-exchanger and a cyclone for separating coal from gas. The simplest and most reliable heat-exchanger is a tube of the ascending gas-coal stream. In all modifications of the Systems in each of the stages a parallel stream of coal and a heating agent (gas) is realized and in the system of stages a counter flow is created. The systems have been tested under pilot-plant conditions, proved reliable and make it possible to heat gas and weakly caking coals up to 430-450 deg C without their appreciable degradation. The capacity of industrial systems may amount to 60-80 metric tons per hour. This is satisfactory for the first industrial installations. However, in the future more powerful Systems will evidently be required.A substantial increase of the capacity of the systems developed can be achieved by increasing the pressure of the gaseous heat-carrier in them. This will make it possible to increase the mass of the stream of the heat-transfer agent at the same (or even lower) linear velocity. Thus, the coal stream can be increased proportionately. But the ratio of the water equivalents of the heated and heating agents will be retained. The thermal state of the system, i.e., the temperatures of coal and gas at all points, will also remain unchanged. The ordinary heating system will become a highly efficient system.
展开▼
