CN112747582A

CN112747582A - Single-stage coal slime drying method

Info

Publication number: CN112747582A
Application number: CN202011636434.2A
Authority: CN
Inventors: 宋世果; 张立忠; 张峰; 刘戈; 杨惠茹; 赵廷江
Original assignee: Beijing Zhongkuang Boneng Energy Saving Science & Technology Co ltd
Current assignee: Beijing Zhongkuang Boneng Energy Saving Science & Technology Co ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-05-04

Abstract

The invention discloses a single-stage coal slime drying method, which comprises the following steps: set up a drying chamber, set up feed inlet and discharge gate on drying chamber, make the coal slime be in carry along S type route from the feed inlet to the discharge gate in the drying chamber, to first circulating air is let in to drying chamber ' S middle part, and the coal slime to drying chamber upper portion is dried, first circulating air is got from drying chamber ' S upper portion and is let in drying chamber ' S middle part after the heating, to drying chamber ' S lower part lets in second circulating air, and the coal slime from the bottom up to drying chamber lower part and upper portion is dried, second circulating air is got from drying chamber ' S upper portion and the lower part that lets in drying chamber after the dehumidification heating. The single-stage coal slime drying method is low in energy consumption and cost, can realize accurate drying, and does not discharge smoke and dust.

Description

Single-stage coal slime drying method

Technical Field

The invention relates to the field of coal slime drying, in particular to a single-stage coal slime drying method.

Background

China is a country rich in coal and less in oil, and coal is in a more-than-demand format for a long time. According to the investigation of coal mine washing plants all over the country, some coal slime produced in the coal production process is discharged and stacked in situ, because the coal slime is extremely unstable in shape and does not form by self-flow, the coal slime runs off when meeting water and flies after being dried in the air, the coal slime is abandoned as waste, the environmental protection problem is more serious than that of coal gangue washing, and extremely serious environmental pollution is produced. The other treatment mode is drying by using a dryer, the traditional coal slime drying process mainly comprises a high-temperature drying process of a hot blast stove and a steam heating low-temperature drying process, smoke emission and dust emission exist, the environment is protected, the standard is not easy to reach, the operation cost is high, and the steam low-temperature drying process is limited by a steam heat source.

The coal slime is as the by-product that produces among the washing process, and its transportation, storage, stack have a great deal of environmental protection problems such as environmental pollution occupation of land, and direct marketing economic value is extremely low, and the novel coal slime drying technology of clean, efficient is urgently needed at present, carries out drying process to the coal slime product to improve the economic, the environmental protection benefit of enterprise.

At present, the coal slime drying process adopted by coal mine coal preparation plants can be mainly divided into two main types.

(1) The high-temperature flue gas drying process comprises the following steps: and drying the coal slime filter cake by adopting a hot-blast stove and a roller dryer (or a fluidized bed). The water content of the filter cake of the filter press coal slime is reduced to 13-15% after the filter cake is dried, and the filter cake of the filter press coal slime is in a globular shape and sold separately or mixed with clean coal for external sale. The technology is mature, the yield is high, and a coal-fired hot air furnace and a gas-fired hot air furnace are selected for the hot air furnaces, the heat supply capacity of the coal-fired hot air furnace is below 20 steam tons, and the technology belongs to obsolete equipment; the gas storage source supply safety of the gas hot blast stove and the defects of overproof nitrogen oxide emission, high energy consumption, high operation cost and the like.

(2) And (3) a low-temperature steam drying process: the process utilizes the latent heat of vaporization of steam to heat and dry coal slurry. The steam is indirectly contacted with the coal slime through a steam rotary dryer (or a fluidized bed) to evaporate the moisture in the coal slime. The coal slime low-temperature steam rotary drying technology is a novel environment-friendly drying technology, but the coal slime low-temperature steam rotary drying technology takes steam as a drying heat source, is limited in heat source, has the problems of pollutant emission, dust removal, white elimination and the like, and has the defects of large equipment floor area, small capacity, high energy consumption, high operation cost and the like.

Disclosure of Invention

The invention aims to solve the technical problem of providing a single-stage coal slime drying method which is low in energy consumption and cost, capable of realizing accurate drying and free of smoke and dust emission.

The single-stage coal slime drying method comprises the following steps:

arranging a drying chamber, arranging a feed inlet above the drying chamber, arranging a discharge outlet below the drying chamber,

the coal slime is conveyed along an S-shaped path from the feeding hole to the discharging hole in the drying chamber,

introducing first circulating air into the middle part of the drying chamber to dry the coal slime at the upper part of the drying chamber, wherein the first circulating air is taken from the upper part of the drying chamber and is introduced into the middle part of the drying chamber after being heated,

and introducing second circulating air into the lower part of the drying chamber, drying the lower part of the drying chamber and the coal slime on the upper part from bottom to top, wherein the second circulating air is taken from the upper part of the drying chamber and introduced into the lower part of the drying chamber after dehumidification and heating.

The invention relates to a single-stage coal slime drying method, wherein the concrete steps of conveying coal slime from a feeding hole to a discharging hole along an S-shaped path in a drying chamber are as follows: arrange two or more net chain conveyor in proper order from the top down in the dry chamber, every set up the blow vent on net chain conveyor's the net chain conveyor, make adjacent two net chain conveyor's transport coal slime opposite direction, the coal slime from the top down is carried through two or more net chain conveyor in proper order.

The invention relates to a single-stage coal slime drying method, wherein when coal slime is conveyed by more than two net chain conveyors from top to bottom, high-pressure gas is used for cleaning the net chain conveyor belts of the net chain conveyors.

The invention relates to a single-stage coal slime drying method, wherein the heating of first circulating air comprises the following specific steps: and arranging a first heat pump unit to heat the first circulating air through a condenser of the first heat pump unit.

The invention relates to a single-stage coal slime drying method, wherein the second circulating air is subjected to dehumidification and heating, and the method comprises the following specific steps: and arranging a second heat pump unit to enable the second circulating air to be dehumidified by the evaporators of the first heat pump unit and the second heat pump unit and then heated by the condenser of the second heat pump unit.

The invention relates to a single-stage coal slime drying method, wherein in the specific step of dehumidifying and heating second circulating air, a surface air cooler and a heat recovery device are arranged, the surface air cooler is connected with a cooling tower through a cooling water circulation pipeline, the second circulating air is firstly dehumidified by the surface air cooler and the heat recovery device in sequence, then the second circulating air is dehumidified by evaporators of a first heat pump unit and a second heat pump unit, then the second circulating air is heated by the heat recovery device, and finally the second circulating air is heated by a condenser of the second heat pump unit.

The single-stage coal slime drying method is characterized in that a drying chamber is arranged, a feeding hole is formed above the drying chamber, a discharging hole is formed below the drying chamber, coal slime is conveyed from the feeding hole to the discharging hole along an S-shaped path in the drying chamber, first circulating air is introduced into the middle of the drying chamber to dry the coal slime on the upper portion of the drying chamber, the first circulating air is taken from the upper portion of the drying chamber and is heated and then introduced into the middle of the drying chamber, second circulating air is introduced into the lower portion of the drying chamber to dry the coal slime on the lower portion and the upper portion of the drying chamber from bottom to top, and the second circulating air is taken from the upper portion of the drying chamber, is dehumidified and heated and then is introduced into the lower portion of the drying chamber. Therefore, the air coming out of the drying chamber is divided into two paths, one path is first circulating air, and the first circulating air is heated and then introduced into the middle part of the drying chamber so as to dry the coal slime on the upper part of the drying chamber; and the other path of the second circulating air is dehumidified and heated and then is introduced into the lower part of the drying chamber so as to dry the coal slime at the lower part and the upper part of the drying chamber from bottom to top. In conclusion, the invention has the advantages of low energy consumption and low cost, can realize accurate drying of the coal slime, and has no emission of smoke and dust.

The invention will be further explained with reference to the drawings.

Drawings

FIG. 1 is a schematic structural diagram of a coal slurry drying system for implementing a single-stage coal slurry drying method of the present invention;

FIG. 2 is a schematic structural diagram of a scraper type automatic ash removal device in a coal slime drying system for realizing the single-stage coal slime drying method of the invention;

FIG. 3 is a schematic structural diagram of scrapers in a coal slurry drying system for implementing the single-stage coal slurry drying method of the present invention;

FIG. 4 is a schematic structural diagram of a plugging member in a coal slurry drying system for implementing the single-stage coal slurry drying method of the present invention;

FIG. 5 is a schematic structural diagram of a socket in a coal slurry drying system for implementing the single-stage coal slurry drying method of the present invention;

FIG. 6 is a schematic structural view of the bottom of a scraper in a coal slurry drying system for implementing the single-stage coal slurry drying method of the present invention;

FIG. 7 is a front view of a high pressure gas nozzle in a coal slurry drying system implementing a single stage coal slurry drying process of the present invention;

FIG. 8 is a front cross-sectional view of a high pressure gas nozzle in a coal slurry drying system implementing the single stage coal slurry drying method of the present invention (with the first diversion block seat in the blocking position);

FIG. 9 is a front cross-sectional view of a high pressure gas nozzle in a coal slurry drying system implementing the single stage coal slurry drying method of the present invention (with the first diversion block seat in the conducting position);

FIG. 10 is a front view of a first diversion block seat in a coal slurry drying system implementing the single-stage coal slurry drying method of the present invention;

FIG. 11 is a top view of a first diversion plugging seat in a coal slurry drying system implementing the single-stage coal slurry drying method of the present invention;

FIG. 12 is a top view of a first divert support frame in a coal slurry drying system implementing the single stage coal slurry drying method of the present invention;

FIG. 13 is a front view of a cleaning nozzle in a coal slurry drying system implementing the single stage coal slurry drying process of the present invention;

FIG. 14 is a front cross-sectional view of a cleaning nozzle in a coal slurry drying system implementing the single stage coal slurry drying process of the present invention (with the second diversion block seat in a blocking position);

FIG. 15 is a front cross-sectional view of a cleaning nozzle in a coal slurry drying system implementing the single stage coal slurry drying process of the present invention (with the second diversion block seat in the conducting position);

FIG. 16 is a front view of a second diversion block seat in a coal slurry drying system implementing the single-stage coal slurry drying method of the present invention;

FIG. 17 is a top view of a second diversion plug seat in a coal slurry drying system implementing the single-stage coal slurry drying method of the present invention;

fig. 18 is a top view of a second divert support frame in a coal slurry drying system implementing a single stage coal slurry drying process of the present invention.

Detailed Description

The single-stage coal slime drying method comprises the following steps:

The first heat pump unit and the second heat pump unit both belong to the prior art and respectively comprise a compressor, a condenser, an expansion valve and an evaporator, the four components are connected into a refrigeration loop through pipelines, and a refrigerant is circulated in the refrigeration loop in a reciprocating manner. The refrigerant exothermically condenses as it flows through the condenser and endothermically evaporates as it flows through the evaporator. Therefore, when the first circulating air flows through the condenser of the first heat pump unit, the first circulating air can be heated (the first circulating air exchanges heat with the refrigerant of the first heat pump unit, the refrigerant releases heat, and the first circulating air absorbs heat), the second circulating air can be dehumidified when flowing through the evaporators of the first heat pump unit and the second heat pump unit (the second circulating air exchanges heat with the refrigerant of the first heat pump unit and the second heat pump unit, the refrigerant absorbs heat, and the second circulating air releases heat to separate out condensate water), and the principle that the second circulating air can be heated when flowing through the condenser of the second heat pump unit is the same as the principle that the first circulating air is heated when flowing through the condenser of the first heat pump unit, which is not described herein.

Surface cooler and cooling tower all belong to prior art, and when the second circulating air flowed through the surface cooler, heat exchange took place with the cooling water of flowing through the surface cooler, and the second circulating air is exothermic and is appeared comdenstion water (dehumidification), and the cooling water heat absorption, the cooling water behind the heat absorption is again through cooling water circulation pipeline and is flowed through the cooling tower and release heat, and the cooling water behind the heat release is again through cooling water circulation pipeline and is flowed through the heat that the surface cooler absorbed the second circulating air, so reciprocating cycle.

The heat recovery device belongs to a heat exchanger, which belongs to the prior art, in the invention, the second circulating air can be dehumidified by the heat recovery device and can be heated by the heat recovery device, and the principle is as follows: the air which comes out of the surface air cooler and enters the heat recovery device is called upstream air, the upstream air is high-temperature humid air, the air which comes out of the evaporators of the first heat pump unit and the second heat pump unit and enters the heat recovery device is called downstream air, the downstream air is low-temperature dry air, when the upstream air and the downstream air simultaneously flow through the heat recovery device, the upstream air and the downstream air exchange heat, namely the upstream air releases heat to separate out condensate water (dehumidification), and the downstream air absorbs heat to raise the temperature (heating).

As shown in fig. 1 and combined with fig. 2-18, the coal slime drying system for implementing the single-stage coal slime drying method of the present invention includes a dryer and an air supply device, the dryer includes a drying chamber 6, a feed inlet is disposed above the drying chamber 6, a discharge outlet is disposed below the drying chamber 6, and an upper net chain conveyor unit and a lower net chain conveyor unit are sequentially disposed in the drying chamber 6 from top to bottom. The upper net chain conveyor unit is provided with at least one upper net chain conveyor 8, and when the upper net chain conveyor 8 is set to be more than two, the more than two upper net chain conveyors 8 are sequentially arranged along the up-down direction. The lower mesh chain conveyor unit is provided with at least one lower mesh chain conveyor 17, and when the lower mesh chain conveyor 17 is set to be more than two, the more than two lower mesh chain conveyors 17 are sequentially arranged along the up-down direction. The air supply device comprises a first heat pump unit 49, a second heat pump unit 52, a first air circulation pipeline 26 and a second air circulation pipeline 29 which are respectively connected with a drying chamber 6, air (namely, first circulation air of the invention) in the first air circulation pipeline 26 from the drying chamber 6 is heated by a condenser 27 of the first heat pump unit 49 and then returns to the drying chamber 6 for drying coal slime on the upper net chain conveying unit, air (namely, second circulation air of the invention) in the second air circulation pipeline 29 from the drying chamber 6 is cooled and dehumidified by evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, and then returns to the drying chamber 6 after being heated by a condenser 37 of the second heat pump unit 52 for drying the coal slime on the lower net chain conveying unit and the upper net chain conveying unit from bottom to top in sequence.

As shown in fig. 1, the upper net chain conveyor unit is provided with an upper net chain conveyor 8, the upper net chain conveyor 8 comprises an upper driving sprocket, an upper driven sprocket and an upper net chain conveyor belt, the upper driving sprocket and the upper driven sprocket are both rotatably mounted in the drying chamber 6, the upper net chain conveyor belt is sleeved on the upper driving sprocket and the upper driven sprocket, a plurality of upper vent holes are formed in the upper net chain conveyor belt along the length direction, and the upper driving sprocket is driven by an upper motor. The lower net chain conveyor unit is provided with a lower net chain conveyor 17, the lower net chain conveyor 17 comprises a lower driving chain wheel, a lower driven chain wheel and a lower net chain conveyor belt, the lower driving chain wheel and the lower driven chain wheel are both rotatably installed in the drying chamber 6, the lower net chain conveyor belt is sleeved on the lower driving chain wheel and the lower driven chain wheel, a plurality of lower air vents are formed in the lower net chain conveyor belt along the length direction, and the lower driving chain wheel is driven by a lower motor. The net chain conveyor belongs to the prior art, and its theory of operation is motor drive sprocket, and drive sprocket passes through net chain conveyer belt and drives driven sprocket and rotate together, and net chain conveyer belt can be used for carrying the material. The top of going up net chain conveyer belt and lower net chain conveyer belt is equipped with material turning device 22 respectively, material turning device 22 locates the axis of rotation on drying chamber 6 including rotating, be equipped with a plurality of returning face plates of radially arranging in the axis of rotation, the axis of rotation is through upset motor drive. Under the action of the material turning device 22, the coal slime can be sufficiently turned to be dried.

As shown in fig. 1, the drying chamber 6 is divided into an upper air chamber, a hollow air chamber and a lower air chamber from top to bottom by an upper net chain conveyor 8 and a lower net chain conveyor 17, an upper wind shield 7 is arranged around the upper net chain conveyor 8, the upper wind shield 7 is connected between the upper net chain conveyor 8 and the drying chamber 6, a lower wind shield 9 is arranged around the lower net chain conveyor 17, the lower wind shield 9 is connected between the lower net chain conveyor 17 and the drying chamber 6, the drying chamber 6 at one end of the upper net chain conveyor 8 is provided with the feeding port, the upper wind shield 7 at the other end of the upper net chain conveyor 8 is provided with an upper blanking port 23, one end of the lower net chain conveyor 17 is positioned below the upper blanking port 23, the lower wind shield 9 at the other end of the lower net chain conveyor 17 is provided with a lower blanking port 10, the drying chamber 6 below the lower blanking port 10 is provided with the discharging port, one end of the first air circulation line 26 is connected to the upper air chamber of the drying chamber 6, the other end of the first air circulation line 26 is connected to the hollow air chamber of the drying chamber 6, one end of the second air circulation line 29 is connected to the upper air chamber of the drying chamber 6, and the other end of the second air circulation line 29 is connected to the lower air chamber of the drying chamber 6. It can be seen that the drying chamber 6 and the first air circulation line 26 form a closed air circulation, as does the drying chamber 6 and the second air circulation line 29.

As shown in fig. 1, the upper blanking opening 23 and the lower blanking opening 10 are respectively provided with a baffle 11, and the baffle 11 is used for guiding the coal slurry to fall down.

As shown in fig. 1, a bridge breaking forming distributing machine 3 is arranged at a feed inlet of the drying chamber 6, a bridge breaking device 5 and an extrusion forming distributing device 4 are sequentially arranged in the bridge breaking forming distributing machine 3 from top to bottom, and it should be noted that the bridge breaking forming distributing machine 3 belongs to the prior art, and specific structures and working principles thereof are not described herein again. Broken bridge shaping cloth machine 3's top is equipped with feeding conveyor 1, feeding conveyor 1 includes the feeding action wheel, the feeding from driving wheel and feeding conveyer belt, feeding conveyer belt suit is in the feeding action wheel and the feeding from the driving wheel, the feeding action wheel passes through feeding motor drive, and when the feeding action wheel rotates, it can drive the feeding through the feeding conveyer belt and rotate from the driving wheel together, and the feeding conveyer belt can be used for carrying the material coal slime. The feed conveyor 1 belongs to the prior art, and the detailed structure and working principle thereof are not described herein again. The two ends of the feeding conveyor 1 are respectively a feeding end and a blanking end, the blanking end is positioned right above the bridge-breaking forming distributor 3, and the iron remover 2 is arranged above the feeding conveyor 1. Discharge gate department of drying chamber 6 is equipped with out feed cylinder 14, the last port that goes out feed cylinder 14 is located the below of blanking mouth 10, the below that goes out feed cylinder 14 is equipped with spiral discharge machine 15, the import of spiral discharge machine 15 is located the below of 14 lower ports of feed cylinder, and the export of spiral discharge machine 15 is used for discharging dry material coal slime. It should be noted that the bridge-breaking forming distributor 3, the iron remover 2 and the spiral discharging machine 15 are all in the prior art, and detailed descriptions of the specific structures and working principles thereof are omitted here.

As shown in fig. 1 and fig. 2, a scraper-type automatic ash removal device is disposed at the inner bottom of the drying chamber 6, the scraper-type automatic ash removal device includes a scraper 16, an ash removal driving sprocket 57, an ash removal driven sprocket 59 and a chain 58, the ash removal driving sprocket 57 and the ash removal driven sprocket 59 are respectively rotatably disposed at two ends of the inner bottom of the drying chamber 6, the chain 58 is sleeved on the ash removal driving sprocket 57 and the ash removal driven sprocket 59, the ash removal driving sprocket 57 is driven by an ash removal motor, the scraper 16 is connected to the chain 58, and an ash outlet 56 corresponding to the scraper 16 is disposed on the discharging barrel 14. When the ash removal motor drives the ash removal driving sprocket 57 to rotate, the ash removal driving sprocket 57 drives the chain 58 and the ash removal driven sprocket 59 to rotate together, and the scraper 16 is connected to the chain 58, so that when the chain 58 rotates around the ash removal driving sprocket and the ash removal driven sprocket, the chain 58 can drive the scraper 16 to move back and forth between the ash removal driving sprocket and the ash removal driven sprocket so as to scrape ash. The scraper type automatic ash removal device is started periodically, collected ash at the bottom of the drying chamber 6 is scraped to the ash outlet 56 from one end far away from the ash outlet 56 through the scraper 16, and is discharged out of the drying chamber 6 together with coal slime, and the operation of scraping ash independently can be carried out.

As shown in fig. 3 and with reference to fig. 4-6, the scraper 16 includes a socket 60 and a plug 61, the socket 60 is a triangular barrel structure, the barrel walls of the socket 60 are a first bottom barrel wall 68 and two first side barrel walls 66 that are connected to each other, the first bottom barrel wall 68 is provided with two sliding grooves 69 that are arranged along the length direction of the socket 60, the plug 61 is a triangular column structure, the external shape of the plug 61 matches the barrel cavity shape of the socket 60, the external peripheral walls of the plug 61 are an external bottom wall 64 and two external side walls 63 that are connected to each other, the external bottom wall 64 of the plug 61 is provided with two sliding blocks 65, the plug 61 is inserted into the barrel cavity of the socket 60, the two sliding blocks 65 are respectively located in the two sliding grooves 69, the two external side walls 63 of the plug 61 are respectively provided with a plurality of elastic protrusions 62, every a plurality of elastic protrusions 62 on the lateral wall 63 all arrange along the length direction of plug connector 61, be equipped with on the inner barrel wall of socket 60 with elastic protrusion 62 assorted recess 67, the one end of chain 58 is connected on a first lateral barrel wall 66 of socket 60 and a lateral wall 63 of plug connector 61, the other end of chain 58 is connected on another first lateral barrel wall 66 of socket 60 and another lateral wall 63 of plug connector 61. Thus, during the rotation of chain 58, it pulls the entire scraper 16 in motion, while the scraper 16 is in motion, the first bottom tub wall 68 of socket 60 and the outer bottom wall 64 of plug 61 are against the bottom of drying chamber 6.

As shown in fig. 3 in conjunction with fig. 4-6, the length of the scraper 16 can be adjusted according to the actual situation, i.e. the depth of the plug 61 inserted into the socket 60 is adjusted, when the plug 61 is inserted into or withdrawn from the socket 60, the plug 61 slides in the barrel cavity of the socket 60, and at the same time, the sliding blocks 65 on the plug 61 slide along the sliding grooves 69 on the socket 60. After the length of the scraper 16 is adjusted, the elastic protrusion 62 on the outer side wall 63 of the plug 61 is located in the groove 67 of the inner wall of the socket 60, and the two are clamped to play a limiting role, so that the length of the scraper 16 is fixed. Due to the elastic action of the elastic protrusion 62, when the length of the scraper 16 is adjusted, the elastic protrusion 62 can be pulled out or pushed out of the groove 67 by pulling or pushing the plug-in part 61 relative to the socket part 60, so that the clamping between the two parts is released, and then the scraper 16 is adjusted to the proper length. The elastic protrusion 62 may be made of elastic material such as rubber.

As shown in fig. 1, the upper and lower net chain conveyer belts are all cleaned by the net chain automatic cleaning device, the net chain automatic cleaning device comprises a high-pressure air pump 18, a high-pressure air tank 19 and a high-pressure air nozzle which are sequentially connected through a high-pressure air pipeline 20, the high-pressure air nozzle comprises a first high-pressure air nozzle 21 and a second high-pressure air nozzle 55 which are the same in structure, the first high-pressure air nozzle 21 is arranged between the upper and lower conveyer belts of the upper net chain conveyer belt, the first high-pressure air nozzle 21 is arranged towards the lower conveyer belt of the upper net chain conveyer belt, the second high-pressure air nozzle 55 is arranged between the upper and lower conveyer belts of the lower net chain conveyer belt, and the second high-pressure air nozzle 55 is arranged towards the lower conveyer belt of the lower. The high-pressure air pump 18 and the high-pressure air tank 19 are used as high-pressure air sources and supply high-pressure air to the high-pressure air nozzle, and the high-pressure air nozzle cleans coal slime blocked in the air vent through the high-pressure air. The high-pressure air pump 18 and the high-pressure air tank 19 belong to the prior art, and the detailed structure and the working principle thereof are not described herein.

As shown in fig. 7 and fig. 8-12, each of the first high-pressure gas nozzle 21 and the second high-pressure gas nozzle 55 includes a first cylindrical housing 70, an upper cylinder opening and a lower cylinder opening of the first housing 70 are respectively an airflow inlet and an airflow outlet, the first housing 70 includes an upper cylinder 71 and a lower cylinder 72 which are arranged up and down, an inner diameter of the lower cylinder 72 is larger than an inner diameter of the upper cylinder 71, a first diversion block seat 74 is slidably and sealingly disposed in the upper cylinder 71 of the first housing 70, the first diversion block seat 74 is barrel-shaped, a cylinder opening of the first diversion block seat 74 is arranged toward the upper cylinder opening of the first housing 70, the first diversion block seat 74 includes a second bottom cylinder wall 81 and a second side cylinder wall 84, a first airflow hole 83 is disposed on the second side cylinder wall 84, a first guiding column 79 is connected to an outer side of the second bottom cylinder wall 81, a first diversion support frame 80 is disposed in the lower cylinder 72, the first diversion support frame 80 is provided with a first guide hole 77 corresponding to the first guide post 79, and the first guide post 79 is inserted into the first guide hole 77. The first diversion support frame 80 is provided with a second airflow through hole 76, the second airflow through hole 76 penetrates through the first diversion support frame 80 along the vertical direction, so that the second airflow through hole 76 can conduct the cylinder cavities of the lower cylinder 72, which are respectively positioned above and below the first diversion support frame 80, that is, in the lower cylinder 72, high-pressure gas above the first diversion support frame 80 can flow to the lower part of the first diversion support frame 80 along the second airflow through hole 76. A first spring 75 is connected between the first flow guide plugging seat 74 and the first flow guide support frame 80, a first annular clamping table 82 is fixedly arranged at the lower end of the inner cylinder wall of the upper cylinder body 71, the first flow guide plugging seat 74 is arranged in the first annular clamping table 82 in a sliding and sealing manner (namely, the upper cylinder body 71 is in sliding and sealing with the first flow guide plugging seat 74 through the first annular clamping table 82), a first radial flange 73 is fixedly arranged on the outer side of the barrel mouth of the first flow guide plugging seat 74, a first fixture block 78 is fixedly arranged at the lower end of the first guide column 79, the first fixture block 78 is positioned below the first flow guide support frame 80, and an internal thread for connecting the high-pressure gas pipeline 20 is arranged at the upper end of the inner cylinder wall of the upper cylinder body 71. The end of the high-pressure gas pipeline 20 connected with the high-pressure gas nozzle is provided with an external thread, and the high-pressure gas pipeline 20 is fixedly connected with the high-pressure gas nozzle through a thread.

As shown in fig. 8, when the high-pressure gas nozzle is not supplied with high-pressure gas or the pressure of the high-pressure gas is not enough to compress the first spring 75, the high-pressure gas nozzle is in a blocking state, that is, the first flow guide blocking seat 74 is in the blocking position, at this time, the first flow guide blocking seat 74 separates the high-pressure gas pipeline 20 from the outside, so as to prevent coal ash from entering the high-pressure gas pipeline 20, thereby preventing the high-pressure gas pipeline 20 from being blocked due to the entry of the coal ash. As shown in fig. 9, high pressure gas is introduced into the gas flow inlet of the high pressure gas nozzle, and when the pressure of the high pressure gas reaches a certain degree, the high pressure gas will compress the first spring 75 downwards through the first flow guiding block seat 74 (the high pressure gas acts on the second bottom barrel wall 81 of the first flow guiding block seat 74), and at the same time, the first flow guiding block seat 74 slides downwards along the first annular clamping table 82, and when the first flow guiding block seat slides to a certain position, the first gas flow hole 83 on the second side barrel wall 84 enters into the lower barrel 72, at this time, the first flow guiding block seat 74 is in the conducting position, because the inner diameter of the lower barrel 72 is larger than the inner diameter of the upper barrel 71, when the first flow guiding block seat 74 is in the conducting position, a gap exists between the second side barrel wall 84 and the inner barrel wall of the lower barrel 72, and then the high pressure gas in the barrel cavity of the first flow guiding block seat 74 enters into the gap through the first gas flow, and then enters the cylinder cavity of the lower cylinder 72 above the first diversion support frame 80 through the gap, then enters the cylinder cavity of the lower cylinder 72 below the first diversion support frame 80 through the second air flow through hole 76, and finally is ejected from the air flow outlet. When cleaning is not needed, the high-pressure gas nozzle is disconnected from high-pressure gas, the compressed first spring 75 is extended and reset, then the first flow guide plugging seat 74 slides upwards along the first annular clamping table 82 until the first gas flow hole 83 in the second side barrel wall 84 enters the barrel cavity of the upper barrel body 71, at the moment, the first flow guide plugging seat 74 is in a plugging position, namely plugging is realized through sliding sealing between the first flow guide plugging seat 74 and the first annular clamping table 82, and as a result, coal ash outside the high-pressure gas nozzle cannot enter the high-pressure gas pipeline 20 through the first flow guide plugging seat 74, so that the high-pressure gas pipeline 20 can be prevented from being plugged by the coal ash.

As shown in fig. 8 and in conjunction with fig. 9-12, when the first diversion blocking seat 74 slides up and down along the first annular clamping platform 82, the first guiding column 79 also slides up and down along the first guiding hole 77 of the first diversion supporting frame 80, and the first guiding column 79 plays a guiding role. When the first guide column 79 slides upwards to a certain position, the first clamping block 78 fixedly arranged at the lower end of the first guide column 79 abuts against the first flow guide supporting frame 80 to prevent the first guide column 79 and the first flow guide plugging seat 74 from continuously sliding upwards, and prevent the first flow guide plugging seat 74 from being separated from the first annular clamping table 82 to cause plugging failure. When the first diversion blocking seat 74 slides downwards along the first annular clamping table 82 to a certain position, the first radial flange 73 abuts against the first annular clamping table 82, and at the moment, the first diversion blocking seat 74 is at the maximum conduction position, namely the first air flow hole 83 completely enters the lower cylinder 72. The first radial flange 73 is designed to abut against the first annular locking platform 82, so as to prevent the high-pressure gas nozzle from being damaged due to the excessive pressure of the high-pressure gas, for example, if the first annular locking platform 82 is not provided when the pressure of the high-pressure gas is excessive, the first diversion blocking seat 74 may completely enter the lower cylinder 72, and incline to be locked in the lower cylinder 72 under the action of the high-pressure gas flow, so that the blocking state cannot be recovered.

As shown in fig. 1, one end of a first air circulation line 26 and one end of a second air circulation line 29 are connected to an upper air chamber of the drying chamber 6 through a main air line 25, the first air circulation line 26 is connected to a first fan 28, air in the first air circulation line 26 from the upper air chamber of the drying chamber 6 is heated by a condenser 27 of a first heat pump unit 49 and then returns to a hollow air chamber of the drying chamber 6, the second air circulation line 29 is connected to a second fan 38, a surface air cooler 30 and a heat recovery unit 34, the surface air cooler 30 is connected to a cooling tower 32 through a cooling water circulation line 31, the cooling water circulation line 31 is connected to a cooling water circulation pump 33, and air in the second air circulation line 29 from the upper air chamber of the drying chamber 6 sequentially passes through the surface air cooler 30, the heat recovery unit 34 and an evaporator 35 of the first heat pump unit 49 and the second heat pump unit 52, 36, then the air is heated by the heat recoverer 34 and the condenser 37 of the second heat pump unit 52 in sequence and then returns to the lower air chamber of the drying chamber 6.

As shown in fig. 1, a first fan 28 drives air in the first air circulation line 26 and a second fan 38 drives air in the second air circulation line 29. The first heat pump unit 49 includes a compressor 51, a condenser 27, an expansion valve 50, and an evaporator 35, which are connected by piping to form a refrigeration loop in which a refrigerant is circulated in a reciprocating manner. The second heat pump unit 52 and the first heat pump unit 49 have the same structure, and the second heat pump unit 52 also includes a compressor 53, a condenser 37, an expansion valve 54, and an evaporator 36. The structures and the operating principles of the first heat pump unit 49 and the second heat pump unit 52 are the prior art, and are not described herein again. In the present embodiment, the evaporator 35 of the first heat pump unit 49 and the evaporator 36 of the second heat pump unit 52 share a single casing. When the air in the first air circulation line 26 from the air chamber above the drying chamber 6 passes through the condenser 27 of the first heat pump unit 49, heat exchange with the refrigerant occurs, that is, the air absorbs heat, the refrigerant releases heat and condenses, and the air after absorbing heat returns to the air chamber above the drying chamber 6. When the air in the second air circulation pipeline 29 from the air chamber on the drying chamber 6 flows through the surface air cooler 30, heat exchange is performed between the air and the cooling water, namely the air releases heat and separates out condensed water, the cooling water absorbs heat, the cooling water after absorbing heat enters the cooling tower 32 along the cooling water circulation pipeline 31 to release heat, the cooling water after releasing heat enters the surface air cooler 30 along the cooling water circulation pipeline 31 to absorb heat, and the operation is repeated in a circulating mode. Cooling water can flow along the cooling water circulation line 31, and the power thereof is derived from the cooling water circulation pump 33. The air in the second air circulation line 29 passes through the surface air cooler 30 and then enters the heat recovery unit 34, the air that exits from the surface air cooler 30 and enters the heat recovery unit 34 is called upstream air, the upstream air is high-temperature humid air, the air that exits from the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52 and enters the heat recovery unit 34 is called downstream air, the downstream air is low-temperature dry air, and when the upstream air enters the heat recovery unit 34, heat exchange is performed between the upstream air and the downstream air, namely, the upstream air releases heat and separates out condensed water, and the downstream air absorbs heat. After the heat is released by the heat recovery device 34, the air in the second air circulation pipeline 29 enters the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, and exchanges heat with the refrigerants in the first heat pump unit 49 and the second heat pump unit 52, namely, the air releases heat and separates out condensed water, and the refrigerants absorb heat and evaporate. The air in the second air circulation line 29 is discharged from the evaporators 35, 36 of the first heat pump unit 49 and the second heat pump unit 52 and then enters the heat recovery unit 34, the air entering the heat recovery unit 34 is the downstream air, and the downstream air performs heat exchange with the upstream air in the heat recovery unit 34, that is, the downstream air absorbs heat and the upstream air releases heat. After being heated by the heat recovery device 34, the air in the second air circulation pipeline 29 enters the condenser 37 of the second heat pump unit 52, and exchanges heat with the refrigerant of the second heat pump unit 52, that is, the air absorbs heat, and the refrigerant releases heat and condenses. The air in the second air circulation line 29 is heated by the condenser 37 of the second heat pump unit 52 and then returned to the lower air chamber of the drying chamber 6.

The surface cooler 30, the cooling tower 32 and the heat recovery unit 34 are all in the prior art, and the detailed structure and operation thereof will not be described herein.

As shown in fig. 1, the surface air cooler 30, the heat recovery unit 34 and the condenser 27 of the first heat pump unit 49 are all cleaned by a heat exchanger automatic cleaning device, the heat exchanger automatic cleaning device includes a precipitation filter tank 40, a cleaning circulation pump 41 is arranged in the precipitation filter tank 40, a cleaning water supply pipe 42 is connected to the cleaning circulation pump 41, a cleaning nozzle is connected to the cleaning water supply pipe 42, the cleaning nozzle includes a first cleaning nozzle 43, a second cleaning nozzle 45 and a third cleaning nozzle 47 which are identical in structure, the first cleaning nozzle 43 is used for cleaning the surface air cooler 30, the second cleaning nozzle 45 is used for cleaning the heat recovery unit 34, and the third cleaning nozzle 47 is used for cleaning the condenser 27 of the first heat pump unit 49. The heat recovery device 34 is located above the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, and the bottom of the surface air cooler 30, the bottom of the condenser 27 of the first heat pump unit 49 and the bottoms of the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52 are respectively connected to the precipitation filter tank 40 through a water return pipe 39. The return pipes 39 at the bottoms of the evaporators 35, 36 of the first heat pump unit 49 and the second heat pump unit 52 are provided at the bottom of the common casing of the two evaporators 35, 36, and only one return pipe 39 is required. The return pipe 39 functions as two: firstly, when the cleaning nozzle is used for cleaning the surface air cooler 30, the heat recoverer 34 and the condenser 27 of the first heat pump unit 49, the cleaned sewage can flow back to the precipitation filtering pool 40 along the water return pipe 39, and can be continuously recycled after precipitation filtering; secondly, condensed water generated when air flows through the surface air cooler 30, the heat recovery unit 34 and the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52 is recovered, and the heat recovery unit 34 is positioned above the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, so that the condensed water in the heat recovery unit 34 can flow into a shell shared by the evaporator 35 of the first heat pump unit 49 and the evaporator 36 of the second heat pump unit 52 along the second air circulation pipeline 29, and thus, when the air in the second air circulation pipeline 29 flows through the surface air cooler 30, the heat recovery unit 34 and the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, the condensed water which releases heat and is separated out can flow into the precipitation filter tank 40 along the water return pipe 39 so as to be recovered and utilized.

As shown in fig. 13 and fig. 14 to 18, each of the first cleaning nozzle 43, the second cleaning nozzle 45 and the third cleaning nozzle 47 includes a second casing 85 in a barrel shape, a barrel opening of the second casing 85 is a water inlet, a water outlet 88 is disposed at a barrel bottom of the second casing 85, the second casing 85 includes an upper barrel 86 and a lower barrel 87 which are disposed up and down, an inner diameter of the lower barrel 87 is larger than an inner diameter of the upper barrel 86, a second diversion plug seat 91 is slidably and sealingly disposed in the upper barrel 86 of the second casing 85, the second diversion plug seat 91 is in a barrel shape, a barrel opening of the second diversion plug seat 91 is disposed toward the barrel opening of the second casing 85, the second diversion plug seat 91 includes a third bottom barrel wall 98 and a third side barrel wall 89, a first water through hole 90 is disposed on the third side barrel wall 89, a second guide column 95 is connected to an outer side of the third bottom barrel wall 98, a second flow guide support frame 96 is arranged in the lower barrel body 87, a second guide hole 93 corresponding to the second guide column 95 is arranged on the second flow guide support frame 96, and the second guide column 95 is inserted in the second guide hole 93. The second diversion support frame 96 is provided with a second water flow through hole 92, the second water flow through hole 92 penetrates through the second diversion support frame 96 along the vertical direction, so that the second water flow through hole 92 can conduct barrel cavities of the lower barrel body 87 which are respectively positioned above and below the second diversion support frame 96, that is, in the lower barrel body 87, water flow above the second diversion support frame 96 can flow to the lower part of the second diversion support frame 96 along the second water flow through hole 92. A second spring 97 is connected between the second diversion plug seat 91 and the second diversion support frame 96, a second annular clamping table 99 is fixedly arranged at the lower end of the inner barrel wall of the upper barrel body 86, the second diversion plug seat 91 is arranged in the second annular clamping table 99 in a sliding and sealing manner (namely, the upper barrel body 86 is in sliding and sealing with the second diversion plug seat 91 through the second annular clamping table 99), a second radial flange 100 is fixedly arranged on the outer side of the barrel mouth of the second diversion plug seat 91, a second fixture block 94 is fixedly arranged at the lower end of the second guide column 95, the second fixture block 94 is positioned below the second diversion support frame 96, and an internal thread for connecting and cleaning the water supply pipe 42 is arranged at the upper end of the inner barrel wall of the upper barrel body 86. The end of the cleaning water supply pipe 42 connected with the cleaning nozzle is provided with an external thread, and the cleaning water supply pipe 42 is fixedly connected with the cleaning nozzle through a thread.

As shown in fig. 14, when the water flow is not introduced into the cleaning nozzle or the pressure of the water flow is not enough to compress the second spring 97, the cleaning nozzle is in a blocking state, that is, the second diversion blocking seat 91 is in the blocking position, at this time, the second diversion blocking seat 91 separates the cleaning water feed pipe 42 from the outside, and prevents the coal ash from entering the cleaning water feed pipe 42, so that the cleaning water feed pipe 42 can be prevented from being blocked due to the entry of the coal ash. As shown in fig. 15, a water flow is introduced into the water inlet of the cleaning nozzle, and when the pressure of the water flow reaches a certain level, the water flow compresses the second spring 97 downward through the second diversion block seat 91 (the water flow acts on the third bottom barrel wall 98 of the second diversion block seat 91), and at the same time, the second diversion block seat 91 slides downward along the second annular locking platform 99, when the second diversion block seat 91 slides to a certain position, the first water flow through hole 90 on the third side barrel wall 89 enters the lower barrel 87, at this time, the second diversion block seat 91 is in the conducting position, because the inner diameter of the lower barrel 87 is larger than the inner diameter of the upper barrel 86, when the second diversion block seat 91 is in the conducting position, a gap exists between the third side barrel wall 89 and the inner barrel wall of the lower barrel 87, so that the water flow in the barrel cavity of the second diversion block seat 91 enters the gap through the first water flow through hole 90 and then enters the barrel cavity of the lower barrel 87 located above the second diversion support 96, then enters the barrel cavity of the lower barrel body 87 below the second diversion support frame 96 through the second water flow through hole 92, and finally is sprayed out from the water flow outlet 88. When not needing to wash, washing nozzle disconnection rivers, the extension of compressed second spring 97 resets, then second water conservancy diversion shutoff seat 91 upwards slides along second annular ka tai 99, enter into the bucket intracavity of upper barrel body 86 until first rivers through-hole 90 on third lateral wall 89, at this moment, second water conservancy diversion shutoff seat 91 is in the shutoff position, that is to say, the shutoff has been realized through the sliding seal between second water conservancy diversion shutoff seat 91 and the second annular ka tai 99, the result is exactly, the outer coal ash of washing nozzle can't enter into through second water conservancy diversion shutoff seat 91 and wash in the water supply pipe 42, thereby can prevent that wash the water supply pipe 42 from being blockked up by the coal ash.

As shown in fig. 14 and 15, when the second diversion blocking seat 91 slides up and down along the second annular clamping table 99, the second guide column 95 also slides up and down along the second guide hole 93 of the second diversion supporting frame 96, and the second guide column 95 plays a role of guiding. When the second guide post 95 slides upwards to a certain position, the second fixture block 94 fixedly arranged at the lower end of the second guide post 95 abuts against the second flow guide support frame 96, so that the second guide post 95 and the second flow guide plugging seat 91 are prevented from continuously sliding upwards, and the second flow guide plugging seat 91 is prevented from being separated from the second annular fixture table 99 to cause plugging failure. When the second diversion sealing seat 91 slides downwards to a certain position along the second annular clamping table 99, the second radial flange 100 abuts against the second annular clamping table 99, and at the moment, the second diversion sealing seat 91 is at the maximum conduction position, namely, the first water flow through hole 90 completely enters the lower barrel 87. The second radial flange 100 is designed to abut against the second annular locking platform 99, so as to prevent the cleaning nozzle from being damaged due to the excessive pressure of the water flow, for example, if the second annular locking platform 99 is not provided when the pressure of the water flow is excessive, the second diversion blocking seat 91 may completely enter the lower barrel 87, and incline and be locked in the lower barrel 87 under the action of the water flow, so that the blocking state cannot be recovered.

As shown in fig. 1, the connection cleaning nozzle end of the cleaning water supply pipe 42 is connected with a first branch water supply pipe, a second branch water supply pipe and a third branch water supply pipe, the first branch water supply pipe is connected with a first cleaning nozzle 43, the first branch water supply pipe is provided with a first valve 44, the second branch water supply pipe is connected with a second cleaning nozzle 45, the second branch water supply pipe is provided with a second valve 46, the third branch water supply pipe is connected with a third cleaning nozzle 47, and the third branch water supply pipe is provided with a third valve 48. The operating state of the cleaning nozzle can be controlled by the opening and closing operation of the valve.

As shown in fig. 1, a double exhaust valve 24 is arranged on the main air pipeline 25, an external circulation air inlet is arranged on the lower air chamber of the drying chamber 6, a double intake valve 13 is arranged at the external circulation air inlet, and a third fan 12 is arranged at the external circulation air inlet in the drying chamber 6. Through the detection of the intelligent detection control system, when the ambient temperature and humidity outside the drying chamber 6 are appropriate, the first fan 28 and the second fan 38 are closed, the dual air inlet valve 13, the dual air outlet valve 24 and the third fan 12 are opened (the centrifugal fan is selected for the third fan 12), and the coal slime is dried by using the outside air.

As shown in fig. 1, the coal slurry drying system for implementing the single-stage coal slurry drying method of the present invention is sequentially provided with an upper-mesh chain conveyor unit and a lower-mesh chain conveyor unit from top to bottom in a drying chamber 6, coal slurry to be dried enters the drying chamber 6 from a feed port above the drying chamber 6 and falls on the upper-mesh chain conveyor unit, the coal slurry is conveyed to the lower-mesh chain conveyor unit by the upper-mesh chain conveyor 8 along with the rotation of the upper-mesh chain conveyor 8 (when the upper-mesh chain conveyor unit is provided with more than two upper-mesh chain conveyors 8, the coal slurry is conveyed to the lower-mesh chain conveyor 8 from the upper-mesh chain conveyor 8 to the lower-mesh chain conveyor unit along with the rotation of the upper-mesh chain conveyor 8), and then the coal slurry is conveyed to a discharge port below the drying chamber 6 by the lower-mesh chain conveyor 17 along with the rotation of the lower-mesh chain conveyor 17 (when the lower-mesh chain conveyor unit is provided with more than two lower-mesh chain conveyors 17 Meanwhile, with the rotation of the lower mesh chain conveyor 17, the coal slurry is conveyed from the last lower mesh chain conveyor 17 to the next lower mesh chain conveyor 17 until the lower mesh chain conveyor 17 at the lowermost end conveys the coal slurry to the discharge port), and is discharged. In the process of conveying the coal slime in the drying chamber 6, the air from the drying chamber 6 in the first air circulation pipeline 26 is heated by the condenser 27 of the first heat pump unit 49 and then returns to the drying chamber 6 for drying the coal slime on the upper net chain conveyor unit, and the air from the drying chamber 6 in the second air circulation pipeline 29 is cooled and dehumidified by the surface air cooler 30, the heat recoverer 34 and the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52 in sequence, and then is heated by the heat recoverer 34 and the condenser 37 of the second heat pump unit 52 and then returns to the drying chamber 6 for drying the coal slime on the lower net chain conveyor unit and the upper net chain conveyor unit in sequence from bottom to top. It can be seen that the air coming out of the drying chamber 6 is divided into two paths, one path entering the first air circulation line 26 and returning to the drying chamber 6 through the first air circulation line 26; the other way into the second air circulation line 29 and back to the drying chamber 6 via the second air circulation line 29. In conclusion, the coal slime drying system for realizing the single-stage coal slime drying method has the advantages of small occupied area, low energy consumption and low operation cost, can realize accurate drying, and does not discharge smoke and dust.

The working process of the coal slurry drying system for implementing the single-stage coal slurry drying method of the invention is described below.

As shown in fig. 1, the coal slurry (water content is 25% -30%) is fed into the broken bridge forming distributor 3 through the iron remover 2 by the feeding conveyor 1, the coal slurry is extruded into uniform particles and then spread at one end of the upper-mesh chain conveyor 8, the upper-mesh chain conveyor 8 rotates, the coal slurry is conveyed to the other end of the upper-mesh chain conveyor 8 and drops at one end of the lower-mesh chain conveyor 17 through the upper dropping port 23, the lower-mesh chain conveyor 17 rotates, the coal slurry is conveyed to the other end of the lower-mesh chain conveyor 17 and drops into the discharging barrel 14 of the discharging port through the lower dropping port 10, the coal slurry enters the spiral discharging machine 15 through the discharging barrel 14, and the dried coal slurry (water content is 10% -15%) is finally discharged through the spiral discharging machine 15. A plurality of material turning devices 22 are arranged above the upper net chain conveyor 8 and the lower net chain conveyor 17 to turn over coal slime particles so as to fully dry the coal slime particles. The coal slime tiling is on last net chain conveyor 8 and lower net chain conveyor 17, a plurality of blow vents that go up have evenly been seted up along length direction on the net chain conveyor of going up, a plurality of blow vents down have evenly been seted up along length direction on the lower net chain conveyor of going up, net chain conveyor 8 and net chain conveyor 17 have the deep bead down all around, the air passes through from the lower blow vent of net chain conveyor belt down and the last blow vent of net chain conveyor of going up, simultaneously with the coal slime contact heat transfer, take away the moisture in the coal slime (dry coal slime promptly), become humid air, discharge from the last air chamber of dry cavity 6, get into air supply device. The wet air entering the air supply device is divided into two paths, one path of wet air enters the first air circulation pipeline 26, is directly heated by the condenser 27 of the first heat pump unit 49 and then is driven by one or more first fans 28 (the first fan 28 adopts an axial flow fan) to return to the hollow air chamber of the drying chamber 6, and the coal slime on the upper net chain conveyor 8 is dried; the other path of wet air enters a second air circulation pipeline 29, is cooled and dehumidified by the surface air cooler 30, the heat recoverer 34 and the evaporators 35 and 36 of the first heat pump unit 49 and the second heat pump unit 52, is heated by the heat recoverer 34 and the condenser 37 of the second heat pump unit 52, is driven by one or more second fans 38 (centrifugal fans are used as the second fans 38) to return to a lower air chamber of the drying chamber 6, and is used for drying the coal slime on the lower net chain conveyor 17 and the upper net chain conveyor 8 from bottom to top in sequence; finally, the coal slurry is collected and discharged from an upper air chamber of the drying chamber 6 to a main air pipeline 25, and then enters a first air circulation pipeline 26 and a second air circulation pipeline 29 respectively, and the circulation is carried out, so that the coal slurry is dried by closed circulation air.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.

Claims

1. A single-stage coal slime drying method is characterized by comprising the following steps:

2. The single stage coal slurry drying method as recited in claim 1 wherein the step of conveying the coal slurry along an S-shaped path from the inlet to the outlet in the drying chamber comprises: arrange two or more net chain conveyor in proper order from the top down in the dry chamber, every set up the blow vent on net chain conveyor's the net chain conveyor, make adjacent two net chain conveyor's transport coal slime opposite direction, the coal slime from the top down is carried through two or more net chain conveyor in proper order.

3. The single stage coal slurry drying method of claim 2 wherein: when the coal slime is conveyed by more than two net chain conveyors from top to bottom, the net chain conveying belt of the net chain conveyor is cleaned by high-pressure gas.

4. The single-stage coal slime drying method of claim 3, wherein the heating of the first circulating air comprises the following specific steps: and arranging a first heat pump unit to heat the first circulating air through a condenser of the first heat pump unit.

5. The single-stage coal slime drying method of claim 4, wherein the second circulating air is dehumidified and heated by the following steps: and arranging a second heat pump unit to enable the second circulating air to be dehumidified by the evaporators of the first heat pump unit and the second heat pump unit and then heated by the condenser of the second heat pump unit.

6. The single stage coal slurry drying method of claim 5 wherein: and in the specific step of dehumidifying and heating the second circulating air, a surface air cooler and a heat recoverer are arranged, the surface air cooler is connected with a cooling tower through a cooling water circulation pipeline, the second circulating air is firstly dehumidified through the surface air cooler and the heat recoverer in sequence, then the second circulating air is dehumidified through evaporators of the first heat pump unit and the second heat pump unit, then the second circulating air is heated through the heat recoverer, and finally the second circulating air is heated through a condenser of the second heat pump unit.