Method for controlling coking coal dampness

Abstract

The invention relates to a method for controlling the humidity of coking coal, belonging to the technical field of coking coal preparation. The technical problem to be solved in the invention is to provide a method for controlling the humidity of coking coal with simple process and less equipment; the method also can effectively reduce the oxygen content of a drying system and guarantee the safety of the system. The method can make full use of the back-pressure steam generated after dry quenching steam power generation or other low-pressure steam and coke oven waste gas in plants, utilizes steam for indirect drying and takes the waste gas generated in the coke oven production process as carrier gas for direct drying at the same time. The method can improve the drying efficiency of a drying machine, prevent the condensation of moisture after drying, reduce the oxygen content in the system (keeping the oxygen content of the system below 13% steadily), prevent the ignition and explosion of the system, improve the running safety of the system, lower the consumption of steam, reduce running cost and have promising market prospect.

Description

technical field [0001] The invention relates to a method for controlling the humidity of coking coal, belonging to the technical field of coking coal preparation. Background technique [0002] In the preparation process of coking coal, there is often a large amount of water due to washing, weather and other reasons, resulting in reduced coke oven production capacity, increased coking heat consumption, poor coke quality, increased ammonia distillation wastewater, and coke oven waste. The life expectancy is also greatly affected. Due to the depletion of coking coal resources, a large number of tamping coke ovens will be built. The tamping coke ovens have higher requirements on the moisture stability of coal materials. In order to meet production needs and control the moisture content of coking coal within a certain range, the industry has developed a A series of coal moisture control methods (CoalMoisture Control referred to as CMC). At present, there are mainly three CMC me...

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Problems solved by technology

At present, there are mainly three CMC methods: one is the heat transfer oil humidity control method, which uses the heat transfer oil to recover the waste heat of the coke oven flue gas and the sensible heat of the coke oven riser, and then uses the heat transfer oil to control the coal in the multi-tube rotary dryer. Indirect heating is carried out to dry the coal material. This kind of coal humidity control system has complicated process, huge equipment, many operation links, high failure rate and high investment. It is rarely built now.

The second is the steam humidity control method (rotary dryer coal humidity control), which uses the back pressure steam after coke dry quenching steam power generation or other low-pressure steam in the factory as a heat source. Indirect heating and drying, steam coal humidity control device has less equipment and simple process, but the steam consumption is large, the oxygen content of the system is not suitable for control, and fire accidents are prone to occur

This humidity control method directly exchanges heat between the coal material and the flue exhaust gas, which has high efficiency, but because 10% to 30% of the fine coal powder is carried out by the exhaust gas, it is necessary to install a huge dust removal facility.

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