RU2216572C1 - Method of coal-aerosol power-plant fuel production - Google Patents

Abstract

FIELD: heat-power engineering, technology of coal-aerosol power-plant fuel production. SUBSTANCE: invention relates to technology of production of the efficient and ecologically pure solid fuel on the basis of coal, that may be utilized for incineration in boilers, furnaces and other installations of heat-power engineering. Coal- aerosol fuel made on the basis of micronized activated coal and hydrocarbon compounds is produced by preliminary comminution of large-sized lumpy coal up to 2-3 mm in the devices provided with magnetic traps for trapping non- grinded metal impurities with following thin grinding exercised by a jet-rotor grinder up to particle sizes of 17-20 micromicrons and at the high-speed mode of operation lead up the coal moisture to 1-3 % with production of a stable aerosol system of heightened calorific value and the given moisture. EFFECT: production of the efficient and ecologically pure coal-aerosol power-plant fuel. 4 cl

Description

 The invention relates to the production of fuel, in particular to energy fuel based on a two-phase aerosol, the solid phase of which is represented by finely dispersed activated carbon with increased adsorption ability, and the air (gas) phase with significant impurities of volatiles, the output of which is observed during high-frequency and multiple collisions of particles in a jet rotary grinders.

 Coal-aerosol fuel can be used for combustion in boilers, furnaces and other heat power facilities.

 The closest technical solution to solve the technical problem is a method for producing coal-aerosol energy fuel based on activated carbon of hydrocarbon compounds capable of adsorbing on the surface of the solid phase, including coal preparation with preliminary grinding of large-sized lump coal to initial size and subsequent fine grinding of coal into jet rotary mill (RU 2166367, class B 02 C 7/08, 05/10/2001).

 Without begging the merits of the known method, nevertheless, it should be noted that although it is provided, including in the energy sector, for grinding various materials, it is not disclosed to what criteria it is necessary to perform grinding to obtain particles of a given fraction and humidity.

 The proposed method is devoid of the above drawback and provides the production of coal-aerosol energy fuel based on activated carbon and hydrocarbon compounds capable of adsorbing on the surface of the solid phase to obtain particles of a given fraction and their moisture content.

 The solution to the technical problem is provided by the fact that the method of producing coal-aerosol energy fuel based on activated carbon and hydrocarbon compounds capable of adsorbing on the surface of the solid phase includes coal preparation with preliminary grinding of large-sized coal to initial size and subsequent grinding of coal in a jet rotary mill, with this coal preparation with preliminary grinding of large-sized lump coal is carried out by grinding coal up to 2-3 mm in devices with magnetic traps for collecting impenetrable metal inclusions, after which the coal jet is finely ground to a particle size of 17-20 microns and, with a high-speed operating mode, the coal humidity is adjusted to 1-3% to obtain a stable aerosol system.

 In addition, the drying of wet coal is carried out by fine grinding in a jet-rotary mill due to multiple collisions and high contact temperatures.

 After grinding in the rotor part of the mill, the particles of coal are informed of an exit velocity of up to 200 m / s and, when impacted by the lining of the mill body made of carbon plates, increase the amount of carbon due to abrasive wear, changing the elemental composition of the coal.

 The method also provides when, during fine grinding of coal, in order to increase calorific value, 1-1.5% hydrocarbon compounds are introduced into the stream, which, adsorbed on the developed surface of the solid phase, intensify the combustion process.

 When grinding in jet-rotor mills to sizes of 17-20 microns, due to the characteristics of grinding, the moisture decreases from 18 to 1-3%, which virtually eliminates the cost of heat for evaporation of moisture and leads to the complete combustion of coal particles. The output of volatiles not participating in the combustion process at the high-frequency grinding stage is reduced from 38 to 8.5%, while the possibilities of traditional grinding equipment, which are equipped with coal preparation departments of thermal power plants, and the standards for upper grinding limits R 90 μm + 7-10% lead to incomplete combustion of coal particles from 20 to 24%. Losses due to this factor make up 30-40% of the total losses.

 The gaseous environment of coal aerosols determines the difference in their properties from the properties of colloidal systems with a dispersed liquid medium, where the solid phase is also represented by micronized particles of coal - water-coal fuel. The ratio of liquid to solid phase, in which it ranges up to (40:60)% and higher.

The main disadvantages of water-coal fuel (VUT) are:
1. High humidity of the exhaust high-temperature gases and combustion products - all this creates them, almost threshold, aggressiveness to the metal structures of the waste gas and the environment.

 2. The evaporation of such a mass of water requires significant energy costs due to increased consumption (HLF), which leads to an increase in specific fuel consumption and reduces its efficiency.

 3. The creation of a stable colloidal system (VUT) requires fine grinding within 3 microns. Use for grinding traditional equipment to such fineness leads to unjustified energy costs.

 4. It is necessary to create chemical water treatment, since the properties of water and the elements of various salts dissolved in it increase the aggressiveness of the outgoing moist gases and contribute to the formation of “acid” rains.

 The technical task of the present invention is to remedy these disadvantages due to the rejection of the colloidal system (liquid and solid phase) and the organization of a coal-aerosol system (gas - solid phase).

The implementation of the proposed method in the substation version consists of the following steps:
- coal preparation with preliminary grinding of large-sized lump coal up to 2-3 mm with magnetic traps from accidental crushed metal inclusions;
- subsequent fine grinding of coal with a fineness of 17-20 microns, mechanical activation and increased adsorption capacity of activated carbon in jet-rotor mills;
- selection from the aspiration system of a gas-air mixture from air and volatiles not participating in the combustion process;
- creation of a device or devices providing conditions for the formation of a stable coal aerosol, its stable burning and the ability to control the flare;
- to increase caloric value, given the increased adsorption capacity of activated carbon and finely ground minerals (impurities) that remained after enrichment (for example, dry tribo-electrostatic enrichment), 1-1.5% hydrocarbon compounds (oil refinery, gas condensate, etc.), which are adsorbed on the developed surface of the solid phase and intensify the combustion process.

 A method of obtaining a coal-aerosol energy fuel based on activated carbon and hydrocarbon compounds is as follows.

 Coal preparation is initially performed with preliminary grinding of large-sized lump coal with a particle size of up to 2-3 mm in devices with magnetic traps for catching random crushed metal inclusions, and then fine grinding of coal with particle dispersion of 17-20 microns is carried out in a jet-rotary mill, creating an increased the adsorption capacity of activated carbon, and with a high-speed mode of operation up to 200 m / s, the coal humidity is adjusted to 1-3% to obtain a stable aerosol system. Wet coal is dried due to multiple collisions with grinding elements and between each other and high contact temperatures. After grinding in the rotor part of the mill, the particles of coal are informed of the exit velocity of up to 200 m / s, and when the mill body made of carbon plates collides with the lining, the amount of carbon is increased due to abrasion, changing the elemental composition. To increase calorific value during fine grinding of coal, 1-1.5% hydrocarbon compounds are introduced into the stream, which, adsorbed on the developed surface of the solid phase, intensify the combustion process. During the grinding period, a partial release of volatiles occurs, which reduces the thermal stability of the fuel.

Claims (4)

 1. The method of producing coal-aerosol fuel based on activated carbon and hydrocarbon compounds capable of adsorbing on the surface of the solid phase, including coal preparation with preliminary grinding of large-sized lump coal to the initial size and subsequent fine grinding of coal in a jet rotary mill, characterized in that the coal preparation with preliminary grinding of large-sized lump coal is carried out by grinding coal up to 2-3 mm in devices with magnetic traps for catching Bani tramp metal inclusions, after which the rotary jet mill micronization performed coal to the particle size of 17-20 microns and at high-speed mode is adjusted to 1-3% moisture to form a stable aerosol systems.  2. The method according to p. 1, characterized in that the drying of wet coal is carried out by fine grinding in a jet rotary mill due to multiple collisions and high contact temperatures.  3. The method according to p. 1, characterized in that the particles of coal after grinding in the rotor part of the mill are reported with an outlet speed of up to 200 m / s and when the collision with the lining of the mill body made of carbon plates increases the amount of carbon due to abrasion, changing the elemental composition of coal.  4. The method according to p. 1, characterized in that when finely grinding coal to increase calories, 1-1.5% hydrocarbon compounds are introduced into the stream, which, adsorbed on the developed surface of the solid phase, intensify the combustion process.