UA55648A - Line for coal drying at dressing works - Google Patents

Abstract

Coal drying line at dressing works has installed in sequence coal-dust furnace of boiling layer with a box of feeding air from blow fan to under movable chain grate, drying drum. Inner surface of the walls of the furnace is equipped with ceramic rod radiators made of material with catalytic activity; in front of the entrance to drying drum a screen is installed, this is made with openings at its area, filled with ceramic pilasters-radiators made of that material with catalytic activity. At the height of the furnace volume there are placed three levels of tangent air inlets from the blow box, and in front of the transverse screen and that ceramic pilasters there is placed a pipe vapor-overheater, for obtaining overheated water vapor.

Description

The invention relates to the coal industry, specifically to coal drying lines in the conditions of high productivity central enrichment factories (CZF) and can be used in the preparation of technical projects and modernization of outdated coal drying lines.

Coal drying at beneficiation plants completes the production cycle and is one of the main processes that determines the moisture content of the product shipped to the consumer. The issues of dehydration and drying of coal concentrates became especially relevant in connection with the wide development of mechanized coal mining, which led to an increased output of small-class coal, as well as in connection with the introduction of sludge flotation at factories.

Fine concentrate (class 0 - 13 mm) with an initial moisture content of 9 - 1295 is dried at coal beneficiation factories; float concentrate (class 0 - О0.5 mm) with an initial moisture content of 24 - 3095 and coal slurry (0 - Zmm), as a rule, in a mixture.

The moisture content of the coal supplied for drying, depending on the percentage of flotation concentrate supplied for drying in its composition, varies widely and is from 12.595 to 3090, and the moisture content of the dried coal is, as a rule, 8 - 995. It is necessary to accurately withstand the given final moisture content of coal, because overdrying is not allowed due to a significant deterioration of the working conditions of the dust cleaning equipment placed in the drying line, and underdrying leads to a deterioration of loose properties and a decrease in the efficiency of coal scattering by dry method. This is especially relevant for factories beneficiating thermal coal, anthracite and low-ash coking coal of small grades.

In the former USSR, as of 1984, the number of beneficiation factories with drying departments was 63, with a volume of processed coal of 54.5 million tons/year. The number of drying devices was 217, including 123 tube dryers, 90 drum dryers and a total of 4 fluidized bed dryers. More than half of coal, 30.7 mln. t/year or 62,195 of its total mass, dried in drum dryers with moisture evaporation

3.5 billion tons/year. More than half of all coal (57,195) was dried in the Donetsk coal basin. This is explained by the use of large-tonnage drum dryers with a diameter of 2.8 m and a length of 14 m. Starting from the end of the 60s, drum dryers of even greater productivity with a diameter of 3.5 m and a length of 27 m have just begun to be used in factories. (see Overview information, issue 4 Filippov V.A. State and development of coal drying at beneficiation factories, MUP of the USSR, TsNDIEDvugillia, Moscow, 1984 (11).

Until now, in drum dryers with a diameter of 3.5 m, as a rule, coal is dried up to 300 t/hour, while up to 27 t/hour of moisture is evaporated in the form of steam with the productivity of smoke extractors at least 100,000 m3/hour.

For example, the drying plant of the Komendantska coal-fired power plant (see (1|)|, p. 19) with an improved chain nozzle in a drying drum with a diameter of 3.5 m and a length of 27 m when drying anthracite of the ASH brand 0 - bmm with an initial moisture content of up to 2295 dries up to humidity 995 when used in a furnace with a fluidized bed as fuel coal of the AS brand with an ash content of 10 - 1495. The temperature of the gas at the entrance to the drying drum is 800 - 900 "C, and at the exit from it up to 150 "C. In drum dryers, the heat consumption is 4000 - 5460kj per kg of evaporated moisture, the electricity consumption per 1t of evaporated moisture is 20 - 75kWh, and for tube dryers, the electricity consumption is estimated as 30 - bOkWh. The consumption of heat and electricity depends on the condition of the equipment, the sealing of the drying tract, the type of drying material and fuel, the productivity of the drying agent, etc. (see V.A. Filipov. Purification of industrial gases at coal enrichment and briquette factories: Moscow, Nadra, 1982, pp. 8-16 |21).

From the given data, it follows that coal beneficiation factories are the largest consumers of electricity and fuel (solid, liquid, gaseous).

One of the main and most complex units of the drying plant is the furnace device, which emits hot flue gases for drying coal. Therefore, technical and economic parameters during the operation of dryers largely depend on the efficiency of the furnace. The consumption of conventional fuel consumed in the furnaces of drying plants is at least 2.2 - 2.595 of the mass of dried coal, that is, a rather large amount of fuel is burned in the furnaces of drying plants. According to estimates, in 1977 in the USSR coal beneficiation factories emitted about 40 billion cubic meters into the atmosphere from burning fuel. flue gases.

The furnaces of drying plants differ from the furnace devices of steam boilers in the absence of cooling surfaces (screen pipes), burning of fuel with increased excess air, which affects the increased output of nitrogen oxides and significant fluctuations in the thermal regime associated with frequent shutdowns of drying plants.

Various types of furnaces for solid fuel are known according to the following classes: with a dense layer; furnaces with a fluidized bed; torch furnaces for burning pulverized fuel; cyclone and vortex furnaces.

Furnaces of the first and second class are arranged both with full combustion of gases in the furnace volume, and in the form of semi-gas furnaces, which are distinguished by the transition of the combustion of gases into the working space of the furnaces in order to develop the highest possible temperature there. Semi-gas furnaces are used mainly for burning lignite and stone coal, as well as anthracite (see A.A. Shchukin. Gas and rough plant management. M-L, 1966, ed.

Energy, p. 131 - 133, 159 - 169; 193 - 199) IZ). Express information TsNDIEDvoguillya, series "Enrichment and briquetting of coal", V.A. Filippov, Ten En Z. Experience in operating furnaces of drying units of coal beneficiation factories, Moscow, 1979 1(4Ї1, V. A. Filippov. Ten En Z. Furnace device of high-performance dryers of foreign coal beneficiation factories, e/i TsNDIEDdvugillia, series "Enrichment and briquetting of coal, Moscow, 1979 (5). In the mentioned review I5|, summaries of pulverized coal furnaces of drying plants in the USA, which ensure the productivity of dryers in terms of evaporated moisture up to 50 - 70 tons/hour, as well as information on fluidized bed furnaces of the "Ignifluid" type, France with a high unit heat capacity and furnaces of the "Duclafluid" type, the USSR.

In all coal beneficiation factories designed and built in the former USSR, a two-stage or three-stage dust collection system was provided. The following dust cleaning system was recommended for dedusting exhaust gases at drying plants: unloading device (I stage dry cleaning) - battery cyclone PBU (II stage - dry cleaning) - PMR wet dust collector (II stage - wet dust cleaning). As a promising system, the following system was considered: unloading device - battery cyclone PBU - horizontal electrostatic precipitator. The main purpose of the dust collection system of drying units is the maximum separation of dried concentrate in dry form from the flow of flue gases (technological cleaning) and the final cleaning of emissions in accordance with the requirements of sanitary standards. A large number of different types of devices for dust collection are used, but each dust collector has its limits of application depending on the size of the dust particles being captured. For catching coarse dust with a size of more than 10 microns, cyclones have become the most popular, because they are simple in design | do not require much maintenance during operation.

For the capture of fine dust smaller than 1 Ωm, as a rule, wet dust capture (HER degree of purification) is used as a sanitary final purification of gases (see V.V. Bobrykiv, V.A. Filippov, Protection of the air pool from pollution by industrial gases, MVP of the USSR , TsNDIEDcoal, series "Technology of beneficiation and briquetting of coal", Moscow, 1975. IbY).

It is known that when burning various types of fuel, especially solid fuel, along with a significant amount of solid particles (ash, dust, soot), sulfur oxides (505 and 503), nitrogen oxides (MOx and MOZ") are emitted into the atmosphere, as well as smaller quantities of carbon monoxide, aldehydes, organic acids. Sulfur oxides are one of the largest emissions and those that are difficult to purify atmospheric air pollutants emitted mainly by power plants. Nitrogen oxides occupy a special place among atmospheric air pollutants. Due to the high toxicity of nitrogen oxides, the maximum permissible one-time concentration of nitrogen oxides in the atmospheric air of cities in the USSR was 5.8 times lower than for sulfuric anhydrite. All over the world, there are particularly strict standards for cleaning emissions into the atmosphere from the specified oxides. With regard to cleaning flue gases of boiler houses, various methods of cleaning gases from sulfur and nitrogen oxides have been developed and are being used in the power industry (see N.Ya. Sigal. Protection of the air pool during fuel combustion. L-d, Nadra, 1977 (|7|), pp. 5-16; 17-38; 195-198; 221-237; Kotlyar V.R. Nitrogen oxide in boiler flue gases, Moscow, Znergoatomizdat, 1987 |8), p. 8; 48-64; 83-86; 106-107; 114-115). For example, a chemical method of cleaning using the injection of liquid ammonia is known, the experience of which is described in the work of A.S. Savenkov. etc. Concentration of solutions in the technology of gas purification from 5O5 and (MOH.

Ecology 98. Proceedings of the conference of the CIS countries on the ecology of chemical production. Chemical technology, m.

Severodonetsk, 15-17 p. 1998 (91.

As a prototype that coincides with the proposed coal drying line in terms of its purpose and main structural components, a drying line with a drum dryer was chosen, shown in fig. 1.1. page 8 of the book:

VA Filippov, Purification of industrial gases at coal beneficiation and briquette factories. Moscow, Nadra, 1982 |2).

The general design features of the coal drying line according to the prototype and the claimed invention are the placement in sequence in the line: a pulverized coal furnace chamber of a fluidized bed with an air supply box from a gas fan under a movable chain grate, to which pulverized coal fuel is fed from a special feeder from above; drying drum, into the inlet of which wet coal from the bunker is supplied through the feeder pipe, and from the outlet of the drum dried coal enters the unloading chamber (I stage of dry cleaning), through the pipeline from the upper part of which the flue gases enter the inlet of the battery cyclone dust collector ( П stage of dry cleaning), from the lower part of which trapped dust is discharged, and from its upper part, flue gases enter the inlet of the smoke extractor, from the outlet of which the flue gases are pumped to the inlet of the wet dust collector (II stage of cleaning), and from its outlet, gases and steam are directed into funnel.

The analysis of scientific and technical and patent information shows that the existing coal drying lines at domestic coal beneficiation factories largely do not correspond to the main trends in the development of modern combustion devices and gas dust cleaning systems developed in the field of energy.

First of all, a significant drawback of coal drying lines is the release of significant amounts of water vapor into the atmosphere without the heat used for water vaporization being utilized. As an example of effective utilization of energy resources, for example, one can cite RF patent Me 2039918 B268 3/084, on a method of drying water-retaining material, which is carried out at a power plant, and a device for its implementation, according to which the dryer works under pressure, and the steam obtained in during the drying process, it is sent in the form of blown steam to the gas turbine.

Heat transfer pipes in the device are mostly straight, thanks to which flow losses are minimized.

It is also known that over the last decade, fluidized bed pulverized coal furnaces have been improved and found effective use in power plants for coal gasification (coal gasification process using the technology of the German company Lurga).

Secondly, there is a failure of the lower part of the wet coal feed pipe due to its placement in the flow of hot combustion gases.

Thirdly, the used fluidized bed combustion chambers have a number of disadvantages: large underburning and removal of pulverized coal fuel (up to 20 - 3095), unsatisfactory organization of the fluidized bed, low radiant heat exchange.

Fourthly, the dust and gas cleaning system does not meet modern requirements.

Therefore, significant costs for the modernization of the existing coal drying lines are expedient with a significant improvement of the technical and economic parameters and the provision of environmental requirements for the protection of the water-air basin.

The essence of the invention.

The invention is based on the task of improving the known coal drying line, which, due to the features of the design of the fluidized bed furnace, the introduction of new blocks into the line and the establishment of connections between the blocks, increases the efficiency of the line in terms of productivity and compliance with environmental standards and requirements.

The general formulation of increasing the efficiency of the coal drying line specifically means ensuring the increased completeness of the combustion of pulverized coal fuel in the fluidized bed furnace with a simultaneous reduction in the formation of nitrogen oxides, the use of the obtained additional amount of heat for the production of superheated steam for preliminary drying of wet coal, condensation of water vapor from flue gases with utilization their heat, neutralization of flue gases from acidic impurities and improvement of their cleaning before discharge into the chimney.

The task is solved by the fact that in the coal drying line of the beneficiation factory, which contains a fluidized bed pulverized coal furnace with an air supply box from a gas fan under movable chain grates, to which pulverized fuel is fed from above from a special feeder, a drying drum is installed in series, into the inlet of which wet coal is supplied from the hopper through the feed pipe, and dried coal from the drum outlet enters the unloading chamber, which is the first stage of dry cleaning, through the pipeline from the upper part of which flue gases enter the dust collector of the second stage of dry cleaning, from the lower part of which trapped dust is unloaded, and through the pipeline from its upper part, flue gases enter the inlet of the vacuum cleaner, from the outlet of which the flue gases are pumped into the wet dust collector as the third stage of wet cleaning, from the outlet of which the flue gases are directed into the flue, according to the invention, the inner surface of the walls furnace is equipped with ceramic rod emitters made of a material with catalytic activity, a transverse screen installed before the entrance to the drying drum is made with holes over its area, filled with ceramic pilasters-emitters made of the specified material with catalytic activity, the total area of the pilaster holes is equivalent to the area of the entrance opening to the drying drum, along the height of the furnace volume, there are three tiers of tangential air intake from the dust box, and in front of the transverse screen and the specified ceramic pilasters, a tubular steam superheater is placed for obtaining superheated steam, from the outlet of which the steam enters the wet coal bunker, the feeder pipe from the bunker and into the pipe steam jet dryer for drying an additional amount of wet coal placed in the area of the drying drum, the second stage of dry cleaning of flue gases is made in the form of a cyclone device with counter-rotating flows of flue gases, an attachment is installed behind the flue gas this line of steam condensation and wet dust cleaning of gases in the form of a vortex turbocyclone based on a multi-chamber film apparatus connected to a system for neutralizing gases from sulfur and nitrogen oxides, a system for removing wet sludge to a sump with the release of excess contaminated water for further treatment, as well as systems for utilization and use of condensate heat.

The listed features make up the essence of the invention, because they are necessary in any variant of the invention and are sufficient to achieve the set task.

The detailed design differences of improvements to the combustion chamber, ceramic radiators and screen, steam jet dryer, turbocyclone with a 502 and MOH washing system, as well as the irrigation system of the third stage of wet dust cleaning of gases will be disclosed additionally on the basis of independent applications for inventions.

The cause-and-effect relationship between the distinctive features introduced into the coal drying line and the technical result achieved is as follows.

Increasing the completeness of the combustion of pulverized coal fuel and, therefore, the thermal stress of the combustion chamber is achieved by many improvements, including uniform loading of coal across the entire width of the chain grates, prevention of fuel particles being carried into the ash pan, increasing the emissivity of the walls of the internal volume due to the heating of ceramic elements, redistribution of air along furnace volume with the help of tangential inputs, gas turbulence on the surface of the walls. The redistribution of air, in particular, contributes to the effective mixing of gases, reducing the formation of nitrogen oxides and improving the cooling of the walls. The best scheme for modernizing the internal furnace space is the installation of ceramic rods and ceramic pilasters in the walls of the center of the opening and the transverse screen.

The total radiation surface of the installed ceramic elements can additionally provide up to 4096 thermal stress of the entire combustion volume without increasing fuel consumption, which can then be used to obtain superheated steam.

The effectiveness of processes occurring on the surface of ceramic radiating elements made of material with catalytic activity is as follows. Ceramics made of natural kaolin (aluminosilicate) after firing in furnaces at 1200 - 14002C has the properties of a catalyst for the destruction of hydrocarbon raw materials.

In the radiation zone of ceramics with catalytic properties, the destruction of hydrocarbon gases in the presence of water vapor occurs at significantly higher speeds compared to the thermal process of combustion. In the radiation zone, ozone is formed from molecular oxygen under the action of UV radiation and COg is assimilated into combustion products (Hg, СО, СНа) due to photosynthesis, which reduces the formation of toxic gases and reduces dustiness, increasing the intensity of radiation with the release of heat.

In the area of high temperatures of 800 - 1000"C, an intense thermal effect of infrared rays is also created on particles of unburnt organic products of coal and dust that fall between the surfaces of the radiation sources of rods and pilasters, which contributes to instantaneous combustion due to chemical transformations and photochemical reactions.

The heat generated by the radiators is used to superheat the steam through a superheater installed in front of the transverse screen partition and ceramic radiators ("used by three streams.

The first stream of steam is used in the tube steam dryer to dry the additional mass of raw coal material, and the second stream of steam is used in conjunction with feeding the tube of the loading feeder of the raw wet coal, while the third stream is directed to the hopper of wet material, which is fed into the drying drum. The steam introduced into the feeder pipe simultaneously performs the role of preliminary initial drying, which pushes the coal into the drum, protects the coal loading feeder pipe and the drying drum from overheating with combustion gases and from burning out. When the steam jet dryer is turned off, the steam received in the superheater can successfully perform the role of a tube dryer in the loading pipe of the feeder.

An increase in the degree of dry cleaning of gases in the second stage of cleaning can be achieved by replacing battery cyclones with VZP devices - cyclones with oncoming swirling flows of flue gases being cleaned. These cyclones more effectively capture finely dispersed dust with a particle size of less than 5 μm, work stably when the gas load changes within 3090 from the nominal one, and have 2.5 times less hydraulic resistance. Productivity of VZP gas cyclones is up to 100,000 m3/hour.

The efficiency of wet gas cleaning is increased due to the introduction of a vortex turbocyclone.

Three chambers are mounted in the turbocyclone - for gas cooling, steam condensation and separation of finely dispersed sludge, and in the fourth chamber at the exit of gases from the turbocyclone, a system of new electron beam technology can be mounted, with the help of which the outgoing gases are irradiated with a high content : sulfur dioxide 1600 ppm; nitrogen oxides bOOrrm; ash (dust) - 1000 rrm.

A significant advantage of the vortex turbocyclone is the low resistance to gas movement due to steam condensation in each subsequent chamber.

When using an industrial accelerator with a capacity of 50 kW with a particle energy of 1.5 MEV, a high degree of capture of 50: and MOH up to 80...9095 is achieved. In order to bind the oxides in front of the irradiation chamber, ammonia is injected into the passing gas in a stoichiometric ratio, which is formed in the gas phase of a mixture of sulfate and ammonium nitrate (ANH) in a ratio of 4:1. Next, the mixture is concentrated by circulating through a turbocyclone and upon reaching a high concentration of SNA or water according to gas analysis of МОх - 50 - 100 ppm and 50" - 100 - 150 ppm water is partially sent to the consumer for use in order to obtain ammonium sulfite-nitrite fertilizer up to 25 - 3095 concentration. The method was tested at the Slovyanskaya GRES according to the development of the Kharkiv Polytechnic University, Kharkiv (Materials of the 111th conference of the CIS countries on the ecology of chemical production, Severodonetsk.

Chemical technology (institute) Ecology 98, September 15-17. 1998 (91

Other known methods of neutralization and purification of gases from 5O»2 and MOx oxides, which are given above, can be used (see 7, 81.

Of great interest is the use of a solution of magnesium oxide (MoO(OH)26) for cleaning flue gases without the consumption of a reagent according to the reactions:

Na5ZO»z - Myaa(OH)» and H" - Mda5O:z i 2H20

M9zBo:z 6NgO - MobO»z : bNgoO

MO - MO" - MgOz

MgOz - NgO - 2NMO" 2NMO" - MIA(OH)" - Mo(MOz)"2 -- 2H2O.

The cheapest and most accessible method is the addition of 1 - 2.5 mg of urea (urea) per 1 liter of water obtained by condensation (5 - 6 irrigation cycles - 4Okg/shift).

Urea - protects well against corrosion: iron, stainless steel, cast iron. Performs anodic inhibition and shielding of the surface of metals from a corrosive environment. Urea - creates complex insoluble crystals in water with all salts, which can be separated by filtration or removed with sludge from the turbocyclone tray. Urea dissolves well in water (400 grams in 100 g of water at 800 "C. (A.T. Zotov, "Urea",

Goshimvid-vo. Moscow, 1963 (101.

Improving the degree of gas purification is achieved by improving the third wet cleaning in the scheme of the coal drying line. After cleaning in the turbocyclone, the gas passes through the unit of enhanced cooling by condensate injection and is directed to the film cooler, which is improved by more intensive irrigation of the walls of the cooler along the entire height due to nozzles that wash the entire wall. The gas along the wall is directed towards the liquid film of the cyclone apparatus, the cooled steam is directed into the output chimney under the jet plate, which additionally irrigates the output steam and completely condenses it. The resulting condensate collects at the bottom of the cooler and flows down the downpipes into the receiving sedimentation tank with partitions. In the tank, the removal particles settle to the bottom and, after their accumulation, are removed by washing under water pressure from the pump to the sludge clarifier. The illuminated condensate from the tank is removed through the heat exchanger, cooled and directed to the cooling of the gases in the film cooler. The hot condensate undergoes filtration, secondary heating in the heat exchanger and is directed to the boiler, where the heat of the condensate is utilized in the hot water supply system of the enterprise.

Summaries confirming the possibility of making the invention.

The figure shows a diagram of the coal drying line of the TsOF.

The coal drying line of the beneficiation factory contains a furnace chamber - 1, which includes movable chain grates - 2 installed in the lower part, to which pulverized coal fuel is fed by a special feeder - Z.

A box is installed under the chain grates - 4 air supplies from the gas fan - 5 in the zones of the specified grates and tangential input to the furnace.

In the combustion volume of the chamber there is a boar - 6, in the area of the ash pan there is an air intake - 7, to exclude the removal of fuel in the combustion volume there are tangential air intakes - 8, 9, 10, ceramic cylindrical rods on the entire surface of the lining - 11, a transverse screen - 12 with holes between the ceramic pilasters, the total area of which is equivalent to the area of the entrance hole to the drying drum - 13. A tubular coil is placed in front of the ceramic pilasters - 14 for obtaining superheated steam. Supply of wet coal is carried out from the bunker - 15 with the help of the feeder pipe - 16, obliquely introduced through the furnace chamber into the inlet of the rotating drying drum - 13.

In the outer zone of the drying drum, a steam jet dryer - 17 is installed, into which the received superheated hot steam is fed through the pipeline - 18 and at the same time through the pipeline - 19, the hot superheated steam is fed to the feeder pipe - 16 and into the hopper - 15 through two crosses for drying wet coal before feeding it to the pipeline - 19 and dryer - 17.

Next, the drying line contains an unloading chamber - 20 with a transportation system - 21 and loading of dried coal - 22, as well as a pipeline - 23 for supplying flue gases to a dry cleaning dust cleaner - 24,

which is equipped with a system for discharging captured dust - 25, connected by a pipeline - 26 with a smoke exhaust - 27, the exhaust pressure pipeline enters the first of three chambers of a vortex turbocyclone - 28, separated by three partitions controlled by the height above the water level. The fourth chamber - 29 is connected to the system of neutralization of sulfur and nitrogen oxides, for example, with the help of ammonia injection from the apparatus - 30 and the electron beam dust cleaning system - 31, in the pipeline - 32 there is an irrigation device - 33, a swirler of the gas flow - 34 and an additional cooling system with film irrigation - 35. Sludge discharge -36 to the sump - 37, combined with the release of excess contaminated water into the system for further purification and utilization of condensate heat in the heat exchanger - 38, boiler - 39.

The coal drying line works as follows:

Before starting the drying line into operation, the furnace 1 is started according to a special method using a high ignition pipe (not shown in the figure). When burning anthracite in the furnace, it is necessary to ensure an even distribution of fuel from the feeder 3 over the entire width of the chain grates 2, and the speed of its movement must be selected so that active combustion ends at the beginning of the slag zone, into which 40 - 5095 of the total amount of air must be supplied. In the first zone, near the feeder 3, it is necessary to supply a small amount of air from box 4, and the main amount of air, approximately 40 - 50905 of the total amount, is supplied to II, PI and IM zones of active combustion. To reduce the amount of unburned fuel carried into the ash pan, air is supplied through hole - 7. Stabilization of the combustion of pulverized coal fuel in the fluidized bed is ensured at a temperature not lower than 850 - 9002C, when self-heating of the bed takes place. To optimize the combustion regime, it is necessary to maintain a loosened suspended (boiling) layer of coal particles up to 1 m high with intensive circulation of particles throughout the entire volume. Purposeful reduction of the temperature in the furnace is carried out by changing the fuel consumption, because the reduction of the amount of air supplied from the box 4 is limited by the possibility of stopping the boiling of the layer and its subsequent melting. The defined adjustable amount of air supplied from box 4 through paired tangentially placed holes 8, 9, 10 in the walls of the furnace ensures the vortex movement of furnace gases and cooling of the walls. At a temperature of furnace gases of 800 - 9007С, ceramic rods 11, placed on the walls of the furnace and furnace furnace 6, as well as ceramic pilasters 12 in the partition make it possible to increase the emissivity of the walls to compensate for the increased blackness of the boiling layer.

In the tubular coil 14 placed in the furnace volume, steam is supplied through the outlet valve or water under pressure from the boiler room, which allows to obtain superheated steam with a pressure of at least 13 kgf/cm2 and a temperature of more than 2002С. The obtained superheated steam through the pipeline 19 is fed into the pipe of the wet coal feeder 16 from the hopper 15 and, together with the quickly dried wet coal, enters the inlet of the drying drum 13, which rotates around the longitudinal axis obliquely and is installed at an angle of З - 4. The dried coal from the drying drum 13 and from of the steam jet dryer 17 enters the unloading chamber 20 for unloading positions 21, 22, and flue gases and dust - removal through the pipe 23 enter the second stage of dry cleaning of gases from dust, for example, a cyclone of the VZP24 type and further through the pipeline 26 to the outlet of the smoke extractor 27, from the outlet of which flue gases enter the multi-chamber vortex turbocyclone 28 for wet cleaning.

The flue gases enter the chamber 29 for neutralization of sulfur and nitrogen oxides, for example, by irrigation of ammonia from the apparatus 30. Gas purification from 502 and MOH is carried out, for example, with the help of an electron beam device 31 with concentration of the SNA solution in the circulation system of the turbocyclone 28.

Further, the flue gases through the pipeline 32 enter the intensive irrigation device 33 and the gas swirler 34 of the third stage of wet cleaning along the wall of the device upwards towards the irrigation flow 35. The sludge is collected in the lower part and through the holes 36 enters the sump 37 connected to the system 38 sludge collection, water purification and condensate heat utilization 39 and its use.

Thus, the above set of interdependent technical solutions for the improvement of the coal drying line of the beneficiation factory allows to ensure the efficiency of the line in terms of productivity and compliance with environmental standards and requirements. Taking into account the achieved technical result, it is possible to modify the coal drying line of the current production of the CZF with strict observance of the basic technological regime reflected in the regulations and the passport of the coal drying line.

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Mitterya Mam pakhv In NI sna VI Ii ve mail "consumer ev", To Y | her: Y Z se 1 deyuui v u pe beru ut i zo i oti Vi 5 129 58

Fig.

Claims (1)

Coal drying line of the enrichment factory, which contains sequentially installed pulverized coal furnace of a fluidized bed with an air supply box from a dutt fan under movable chain grates, to which pulverized fuel is fed from above from a special feeder, a drying drum, into the inlet of which is fed through the pipe of the feeder from the bunker output wet coal, and from the output opening of the drum, dried coal enters the unloading chamber, which is the first stage of dry cleaning, from the upper part of which flue gases enter the dust collector entrance of the second stage of dry cleaning, from the lower part of which trapped dust is discharged, and from the upper part of the pipeline, flue gases enter the inlet of the smoke extractor, from the outlet of which the flue gases are pumped into the wet dust collector, and from the outlet of the third stage of wet cleaning, the flue gases are directed into the chimney, which is distinguished by the fact that the inner surface of the furnace walls is equipped with ceramic rod radiators, made of material with catalytic activity, a transverse screen is installed in front of the entrance to the drying drum, made with holes over its area, filled with ceramic pilasters-emitters made of the specified material with catalytic activity, the total area of the holes of the pilasters is equivalent to the area of the entrance hole to the drying drum, in height of the furnace volume, there are three tiers of tangential air intakes from the dust box, and in front of the transverse screen and the specified ceramic pilasters, there is a tubular superheater for obtaining superheated steam, from the outlet of which the steam enters the wet coal hopper, the feeder pipe from the hopper, and the tubular steam jet dryer in three streams for drying an additional amount of wet coal placed in the area of the drying drum, the second stage of dry cleaning of flue gases is made in the form of a cyclone device with counter-rotating flue gas flows, an additional steam and wet dust condensation line is installed behind the flue gas purification in the form of a vortex turbocyclone based on a multi-chamber film apparatus connected to a system for neutralizing gases from sulfur and nitrogen oxides and a system for draining wet sludge into a sump with the release of excess polluted water for further treatment and systems for utilization and use of condensate heat.