The coke calcining process varies depending on the calcining equipment used, which also affects the quality of the calcined coke. The selection of calcining equipment should be determined based on a comprehensive consideration of the factory's product range, annual output, raw material quality, and energy availability. Currently, three main types of calciners are commonly used both domestically and internationally: pot calciners, rotary kilns, and electric calciners.
A pot calciner is a thermal kiln in which the carbon raw materials are placed in a calcining pot and heat is indirectly applied by radiation from the refractory brick walls. Commonly used types include co-current pot calciners and counter-current pot calciners. The structure and process of a co-current pot calciner are described. A pot calciner in which the direction of calcining material movement aligns with the overall flow of hot gases is called a co-current pot calciner.
The structure and operating principle of a co-current pot calciner are described. A downstream retort furnace consists of the following main components: the furnace body, including the retort furnace chamber and heating flue; charging, discharging, and cooling systems; gas piping, volatile collection duct, and control valves; an air preheating chamber, flue, exhaust fan, and chimney.
The retort furnace body is composed of several vertically arranged calcining pots of identical structure, built with refractory bricks. Each pot is 3 to 4 meters high, 360 mm wide, and 1.7 to 1.8 meters long. Four calcining pots form a group. Depending on production requirements, each calciner can be configured with 3 to 7 groups. Most retort furnaces consist of 6 groups, for a total of 24 calcining pots. Each calcining pot is flanked by 5 to 8 layers of heating flue, with most having 6 layers.