Pulverized coal milling device and method

Abstract

The invention belongs to the technical field of coal processing, and relates to a pulverized coal milling device and method. The main structure of the pulverized coal milling device comprises a DCS automatic control system, a coal mill, a raw coal supplier, a pulverized coal collecting and storage system and an induced air negative-pressure drying system, wherein the DCS automatic control system is separately connected with the coal mill, the raw coal supplier, the pulverized coal collecting and storage system and the induced air negative-pressure drying system through electric information and controls the operation of the above devices; and the pulverized coal milling method comprises the three steps of operation debugging, formal pulverized coal production and subsequent processing. One time of input and multiple times of output can be realized for pulverized coal milling data, and the whole process is automatically controlled; the DCS automatic control system controls the temperature and air volume of drying air; pulverized coal during a milling process is dried by utilizing low-temperature drying air circulation; a full-negative-pressure pulverized coal conveying mode is adopted by the induced air negative-pressure drying system; and the pulverized coal milling device is simple in structure, scientific and reliable in principles, simple and convenient in operation, precise in control, high in coal milling efficiency, good in safety performance and low in cost, and is energy-saving and emission-reducing.

Description

Technical field: [0001] The invention belongs to the technical field of coal processing, and relates to a pulverized coal preparation device and method thereof, which have the functions of energy saving, environmental protection and full automatic monitoring and control, and are especially suitable for large-scale pulverized coal processing and preparation. Background technique: [0002] Pulverized coal is composed of powders of different sizes and irregular shapes. Generally, the diameter of pulverized coal particles ranges from 0-1000um, and the density of pulverized coal is relatively small. The bulk density of newly ground pulverized coal is about 0.45-0.5t / m 3 , the bulk density after storage for a certain period of time is 0.8-0.9t / m 3 , the pulverized coal particles are very fine, and the pulverized coal per unit mass has a large surface area, and the surface can absorb a large amount of air, so that it has fluidity. This feature makes the pulverized coal easy to be t...

AI Technical Summary

Problems solved by technology

[0002] Pulverized coal is composed of powders of different sizes and irregular shapes. Generally, the diameter of pulverized coal particles ranges from 0-1000um, and the density of pulverized coal is relatively small. The bulk density of newly ground pulverized coal is about 0.45-0.5t / m 3 , the bulk density after storage for a certain period of time is 0.8-0.9t / m 3 , the pulverized coal particles are very fine, and the pulverized coal per unit mass has a large surface area, and the surface can absorb a large amount of air, so that it has fluidity. This feature makes the pulverized coal easy to be transported by pneumatic force. Easy to leak powder when not tight

The preparation methods of coal powder include wet method and dry method: the wet method has the characteristics of good production safety and is used in the preparation process of coal water slurry. The disadvantages are inconvenient storage and transportation, low production efficiency and narrow application range; the dry method is divided into one step One-step method and two-step method, the one-step method refers to drying the raw coal while grinding, which has the characteristics of simple process steps and high safety requirements. The one-step method generally uses high-temperature inert gases such as superheated steam, boiler exhaust gas or nitrogen for drying. Using the principle of reducing the oxygen content in the drying gas, it needs to be used in conjunction with industrial anaerobic tail gas. The heat loss is large when the high-temperature gas is recycled, which limits the site selection of the pulverized coal preparation workshop. When there is no boiler tail gas nearby, a long distance is required. Pipeline transportation, self-built boilers or inert gases such as nitrogen require high costs; the two-step method refers to the separation of the grinding and drying steps of raw coal, which has low safety requirements. The disadvantage is that the process is too long, involving many equipment and ratio Large investment, suitable for small and medium-scale coal powder preparation and pulverization; dust pollution is easy to occur during the transmission process of dry coal powder preparation, and the safety requirements for the storage environment are extremely high

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