IMPROVING THE ENERGY EFFICIENCY OF A ROTARY KILN FOR CALCINING CARBON-CONTAINING RAW MATERIALS

Abstract

An analysis is made of the traditional energy-intensive process of calcining carbon-containing raw materials, in particular petroleum coke, in rotary kilns, which assumes continuous burning of natural gas in these furnaces. A new method for producing calcined petroleum coke is proposed, which minimizes the cost of natural gas as fuel, and therefore reduces the energy intensity of the calcination process and the cost of the obtained calcined coke. In the proposed method, at the beginning of the process, flue gases are obtained by burning natural gas in a rotary kiln, after the calcined coke reaches the required temperature, the consumption of natural gas is reduced or stopped altogether, and the required temperature of the calcined coke is maintained by the corresponding ratio of the flow rate of ambient air and synthetic gas obtained by cooling the material in a rotary kiln or in a cooler drum. To implement the method, a scheme of air supply to the calcination zone of a rotary kiln with the installation of air blowers directly on the casing of a rotary kiln is justified. The fundamental possibility of implementing the proposed method on a rotary kiln diameter 2x40 m with a capacity of 10 t/h for the finished product is shown. In particular, the calculation of its main structural and technological parameters has been performed. Compared with the known method, the proposed technical solution allows to reduce the energy intensity and, accordingly, the cost of the obtained calcined coke. Bibl. 14, Fig. 7.