RU2699642C1 - Device for obtaining separated combustion products of coals - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to coal-processing industry, namely to equipment for production of combustion products separated in specific weight from coal in process of its combustion, suitable for use as raw material for various industries, as well as to obtain a concentrate for extracting gold and other useful components therefrom. Device for obtaining separated combustion products of coal includes furnace chamber with grate inside, connected through lower part of air intake with two-section ash collector with three thermocouples, in first section of which there is afterburner chamber, and the outlet from the second section having a control flap is connected through the flue-pump to the chimney, wherein the latter through the neck is connected to the scrubber, which in its turn is connected to the centrifugal moisture lens, and lower part – with filter unit consisting of in-series connected filter-settler, mechanical coarse filter and fine filter, at that to lower side part of furnace chamber is connected blow fan, inside the chimney there is a sprinkler, by means of a pipeline connected to a pump station located in the lower part of the reservoir for man-made liquid, afterburning chamber in upper part is equipped with a gas burner with a control valve, lower part of air intake – shutter, scrubber neck has adjusting shutters, drain tap at the outlet is equipped with a thermocouple, wherein the fine filter is combined, having a cartridge for fine purification from mechanical impurities and a filter-adsorbent, and as an industrial liquid, both water and an alkaline solution can be used.

EFFECT: invention ensures production of combustion products of coals separated by specific weight and with high degree of purification from carbon.

1 cl, 1 dwg

Description

The invention relates to the coal processing industry, and in particular to equipment for producing from coal during its combustion separated by specific gravity combustion products suitable for use as raw materials for various industries, as well as to obtain concentrate for the extraction of gold and other useful components.

A device is known, - the Experimental Technological Complex “AMUR” (ETK “Amur”) allowing to obtain coal combustion products (CCP) in the form of furnace slag and flue gas treatment products, is published in the collection of reports “Comprehensive use of the potential of hard and brown coals and the creation of combined environmentally friendly safe technologies for their development ”Blagoveshchensk 2017, pp. 117-121. / 1, O.A. Ageev, A.P. Sorokin, V.N. Borisov et al. /

The main disadvantage of this installation is the presence in the combustion products of coal of a large amount of carbon. In the slag and fly ash there are 20-25% of unburned coal (underburning). In the sludge of filtered man-made water, carbon was in the form of tar, soot, small particles of coal and other complex hydrocarbon compounds. According to the laboratory analysis performed by the Center for Laboratory Analysis and Technical Measurements in the Far Eastern Federal District Center for Laboratory Analysis and Technical Measurements in the Amur Region, 68.20 mg / m is contained in gases purified from impurities (after the scrubber) ³ carbon monoxide (Test report No. 325/2d of 10/21/2016).

A large number of carbon-containing compounds in the products of coal combustion impairs the property of the obtained products as raw materials. According to Varshal G.M., Velyukhanov T.K., Koshcheev I.Ya. et al., “On the concentration of precious metals by the carbonaceous matter of rocks” / 2, Geochemistry. 1994. No. 6. S. 814-823 /, “the presence of forms associated with the carbonaceous matter of rocks by the complexation mechanism dramatically reduces the degree of extraction of precious metals in technological and analytical operations. In the analysis of carbon-bearing rocks, the loss of precious metals due to sorption and the formation of volatile compounds can reach 1-2 orders of magnitude. " To reduce the carbon content in CCPs and, therefore, to more efficiently extract gold and other useful components from them, industrial plants require the use of technological methods to achieve a more complete combustion of carbon.

The technical problem solved by this invention is to create a device for controlled combustion of coal in the combustion chamber in a fluidized bed mode, and secondary combustion of volatile fuel compounds in the afterburner located in the ash collector. This allows you to get the combustion products of coal, divided by specific gravity and with a high degree of purification from carbon.

The essence of the invention lies in the fact that in a device for producing separated products of coal combustion, including a combustion chamber with a grate inside, connected through the lower part of the air intake to a two-section ash collector with three thermocouples, in the first section of which there is a afterburner, and the exit from the second section, having a control flap connected through a smoke exhaust with a chimney, the latter through a neck connected to a scrubber, which, in turn, is connected to the centrifugal moisture by the upper part a trap, and the lower part - with a filter unit, consisting of a series-connected filter sump, a mechanical coarse filter and a fine filter, while a blower fan is connected to the lower side of the combustion chamber, a sprinkler sprinkler is located inside the chimney, through a pipe connected to a pump station located in the lower part of the tank for technogenic liquid, the afterburner in the upper part is equipped with a gas burner with a control valve, the lower part of the air the intake pipe is equipped with a shutter, the scrubber neck has control shutters, the outlet moisture trap is equipped with a thermocouple, and the fine filter is combined with a cartridge for fine cleaning from mechanical impurities and a filter adsorbent, and water or an alkaline solution are used as the technogenic liquid.

The invention is illustrated in the drawing. In FIG. 1 is a diagram of a general view of a device consisting of a blower fan 1, a combustion chamber 2, a grate 3, a damper 4, thermocouples 5.1; 5.2; 5.3, 5.4, an air intake 6, a two-section ash collector 7, a regulating flap 8; smoke exhauster 9, chimney 10, sprinkler sprinkler 11, confuser 12, adjustable neck 13, scrubber 14, centrifugal dehumidifier 15, filter settler 16, coarse filter 17, industrial fluid container 18, pump station 19, pipeline 20, gas burner 21, control valve 22, gas pipe 23.

The diagram also indicates: I - coal burned; II - furnace slag; III - fly ash (heavy fraction); IV - fly ash light fraction; V - sludge filter sump; VI - scrubber slurry; VII - sediment man-made liquid; VIII - technogenic fluid.

The device operates as follows.

In the combustion chamber 2, coal I, crushed to 25-30 mm, is burned on horizontal grates 3 in a fluidized bed mode. The formation of a high-temperature fluidized bed and the organization of the coal combustion process is provided by a blower fan 1, which pumps air under the grate (air excess ratio is 1.3-1.5; gas flow rate = 4-5 m / s). The afterburning of products of incomplete combustion of fuel occurs in the afterburner located in the first section of the ash collector 7. The afterburner is equipped with a gas burner 21, where gas - propane enters through the gas line 22 equipped with a control valve 21, the combustion of which (backlight) provides temperature conditions in the afterburner not less than 610 ° С. Upon reaching stable combustion of volatile fuel and a temperature of more than 610 ° C, the burner shuts down. Subsequent burning occurs without backlight. Secondary air enters through the air intake 6 and is regulated by a damper 4. The temperature mode is controlled by thermocouples 5.1; 5.2; 5.3, 5.4. This design of two-stage fuel combustion provides a high degree of purification of coal combustion products from underburning and volatile compounds of carbon and sulfur.

The separation of products by specific gravity is carried out in the process of dry and wet cleaning of flue gases. Light and small particles in the combustion chamber 2 in suspension, due to the forced movement of the air-gas mixture created by the blower fan 1 and the smoke exhauster 9, are carried away from the furnace into a two-stage ash collector 7 with an afterburning chamber for volatile carbon compounds. The speed of the gas stream is regulated by a regulating flap 8. A two-section ash collector is designed for rough cleaning of smoke from solid particles larger than 40 microns.

The principle of operation of the ash collector is dry gravitational enrichment, based on the difference in the speeds of particles having different densities or sizes in the gas stream. In the first section of the ash collector, there is a significant slowdown in the gas flow rate, which facilitates the deposition of the heavy fraction of fly ash III; in the second section, the light fraction of the fly ash IV is precipitated. Fly ash accumulates in the ash bin and is periodically removed. An ash trap provides effective cleaning of flue gases from dust up to 40 microns, keeps the bulk of the trapped dust dry, which allows it to be used as a building material, dramatically reduces the amount of chemically aggressive fluid sludge formed during wet cleaning.

Purified from dust, larger than 40 microns in size, the gas stream, as well as the volatile products of fuel combustion, consisting of hot gases containing oxides of carbon, nitrogen, sulfur, and water vapor, are removed from the ash collector by a smoke exhaust 9 through a chimney 10 to the scrubber 14. Basic scrubber functions - deep cleaning of flue gases from impurities and lowering the temperature of flue gases. The principle of wet cleaning is based on intensive crushing of the irrigating liquid with a dusty gas stream moving at high speed. The scrubber has a smooth narrowing at the inlet of the gases (confuser) 12 and a smooth expansion at the outlet (diffuser). The narrow part is the adjustable neck 13. The cross section of the neck is slotted. With an increase in gas velocity, the interaction of gas and liquid flows proceeds more intensely. The change in gas flow rate is achieved by changing the cross-sectional area of the throat by the adjustment flaps. This design allows you to adjust the speed of the gas stream in the range from 18 to 200 m / s.

As a result of this interaction, dust particles penetrate the liquid upon impact, large droplets of the liquid, along with the captured dust particles, enter the scrubber man-made liquid tray and are continuously discharged into the filter unit for cleaning in the form of sludge. Small droplets of water carried away by the gas flow enter the centrifugal dehumidifier 15, where, under the action of centrifugal force, they settle on the walls of the cyclone and flow into the scrubber pan. The liquid used in the system is water or an alkaline solution (chemisorption). The sprayed droplets must be large enough not to be carried away by the gas stream. The surface area of the droplets should be sufficient to capture all the dust. To implement these requirements, a sprinkler sprinkler 11 is used in the irrigation system.

The purified gases are transported to the atmosphere, and the liquid medium with suspensions enters the filter unit. The filter unit is distinguished by its simplicity of design, compactness and the ability to qualitatively clean the liquid from suspended particles and heavy metal ions. The block consists of three stages of cleaning. The first stage is the filter settler 16. The principle of operation is the flow of man-made fluid into the expanding space of the filter housing, where it loses sharply in speed, and heavy particles settle to the bottom under the influence of gravitational forces. A precipitate is formed - the sludge from the sump filter V, is collected in the lower part of the housing, from where it is periodically removed. The second stage of cleaning is a mechanical coarse filter 17, designed to collect scrubber VI sludge. Principle of work - technogenic liquid passes through the cellular structure, which does not pass further suspended solids. Depth of cleaning is regulated by the sizes of cells. The third stage is a fine filter for extracting dissolved substances from man-made water and sediment of man-made water VII (adsorbent filter). It is supposed to use activated carbon (carbene) or ion-exchange resin as a sorbent. Technogenic liquid VIII is poured into the tank 18, from where the pumping station 19 is fed through the pipeline 20 to the sprinkler sprinkler 11. The water supply is reverse.

The technical result of using the device is as follows: 1. Separate production of CCP even at the stage of coal burning greatly simplifies the technology of utilization of CCP. Gravity and magnetic concentration of furnace slag II and fly ash III, IV allows you to get ready-made raw materials for use in road construction and the production of building materials, as well as raw materials for the metallurgical industry and concentrate containing a number of valuable elements, including native gold. Wet flue gas cleaning products V, VI, VII, according to neutron activation analysis performed at the Institute of Chemistry of the Far Eastern Branch of the Russian Academy of Sciences, are valuable raw materials for non-ferrous metallurgy. The content in the sludge of gold reaches industrial values (1.71 g / t), and lead and iron significantly exceed the content of these elements in the slag and fly ash. / Distribution of macronutrients and gold in coal combustion products (Experimental results) / Ageev OA, Yudakov AA; Ivankov S.I; and other results are published in the collection of reports “Comprehensive use of the potential of hard and brown coals and the creation of combined environmentally safe technologies for their development” Blagoveshchensk 2017, pp. 129-132 /.

2. The applied method of controlled fuel combustion in a fluidized bed mode with secondary mixture formation of unburnt volatile carbon compounds with air in the afterburner provides a high degree of purification of coal combustion products from underburning and volatile carbon and sulfur compounds.

3. The developed and implemented technology of multi-stage purification of flue gases and industrial liquid from harmful and toxic impurities solves the important environmental problem of cleaning emissions from coal combustion.

4. The use of an alkaline solution as an irrigation liquid ensures 90% purification of flue gases from sulfur dioxide emissions (chemisorption). This allows the use of fuel with a high sulfur content for combustion.

Claims (1)

A device for producing separated products of coal combustion, including a combustion chamber with a grate inside, connected through the lower part of the air intake to a two-section ash collector with three thermocouples, in the first section of which there is a afterburner, and the outlet from the second section, which has a control damper, is connected through a smoke exhaust with a chimney, while the latter through the neck is connected to a scrubber, which, in turn, is connected to the centrifugal dehumidifier by the upper part, and to the filter part by the lower part a block consisting of a series-connected filter sump, a mechanical coarse filter and a fine filter, while a blower fan is connected to the lower side of the combustion chamber, a sprinkler sprinkler is located inside the chimney, through a pipeline connected to the pump station located in the lower part containers for technogenic liquid, characterized in that the afterburner in the upper part is equipped with a gas burner with an adjustment valve, the lower part of the air intake is a shutter , The neck has a regulating flap scrubber, demister outlet equipped with a thermocouple, wherein the fine filter is made a combination having a cartridge for fine purification from mechanical impurities and filter the adsorbent, and as the technological liquid can be used both water and alkaline solution.

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