107 results about "Tar" patented technology

The present invention relates to the technical field of tar residue separation, and in particular to an online crushing, slag collection and separation system and process for large tar residue based on a pre-separator, wherein the online crushing, slag collection and separation system for large tar residue based on a pre-separator includes a pre-separator and a pre-separation pipe A and a pre-separation pipe B connected to the outlet end of the pre-separator, a crushing device respectively connected to the outlet ends of the pre-separation pipe A and the pre-separation pipe B, a centrifugal pump and a pretreatment device connected to the outlet end of the centrifugal pump, the crushing device is used to crush tar residue and graphite blocks, and the pretreatment device is used to precipitate and layer the crushed tar, tar residue, graphite blocks and ammonia water mixture; the present invention realizes the crushing, slag collection and drying of large tar residue and graphite blocks through a two-stage crushing treatment method composed of a crushing device and a drying unit, significantly reduces the risk of blockage in subsequent processes, meets the requirements of the coal blending process for material particle size, and improves the availability of tar residue.

The invention relates to the technical field of tar residue separation, in particular to a crushing treatment device for tar residue recovery, which comprises an upper scraping component mounted at the output end of a driving component, and the driving component is used for driving the upper scraping component to rotate on the upper surface of an upper-layer screen and the upper surface of a lower-layer screen. A lower scraping assembly and a transmission assembly are installed in the crushing barrel, the input end of the transmission assembly is connected with the output end of the upper scraping assembly, and the input end of the lower scraping assembly is connected with the output end of the transmission assembly. The driving assembly drives the lower scraping assembly to rotate on the lower surface of the upper-layer screen and the lower surface of the lower-layer screen through the upper scraping assembly and the transmission assembly. The upper scraping assembly is used for cleaning the upper surface of the screen, the lower scraping assembly is used for cleaning the lower surface of the screen, the problem that tar residues adhere to the upper surface and the lower surface of the filter screen is thoroughly solved, and the filtering efficiency is remarkably improved.

The invention discloses a coal tar pretreatment method. According to the method, a magnetic filtering system is included, the magnetic filtering system comprises a magnetic filter, the magnetic filter comprises a magnetic filtering cylinder, multiple layers of magnetic gathering media are arranged in the magnetic filtering cylinder, a magnetic field generating device is arranged outside the magnetic filtering cylinder, and the magnetic field generating device enables a high-gradient magnetic field to be formed in the magnetic filtering cylinder. The method comprises the following steps: heating a coal tar raw material, mixing the heated coal tar raw material with water, a demetallization agent, a flocculant and a magnetic seed, carrying out magnetic filtration, and sequentially carrying out salt leaching, oil-water separation and deep dehydration to obtain refined coal tar. The pretreatment method can effectively remove solid slag, water, salt and metal in the coal tar, and is simple in process flow and low in cost.

The utility model discloses a tar residue crushing device, which relates to the technical field of tar residue crushing and comprises a tar residue crushing device body, a first dredging motor is detachably mounted on one side of the top of the tar residue crushing device body, and a stirring rod is detachably mounted at one end of the output end of the first dredging motor. And two sets of stirring plates are detachably installed on the outer side of one end of the stirring rod in a staggered mode, one end of the stirring rod is connected with a connecting pipe in a penetrating mode, one end of the connecting pipe is connected with one side of the tar residue crushing device body in a penetrating mode, and a second dredging motor is detachably installed on the adjacent side of the tar residue crushing device body. According to the tar residue crushing device, the arranged stirring rod is matched with the stirring plate to distribute and dredge tar residues flowing out of the end of the connecting pipe, blockage of the tar residues at the end of the connecting pipe is prevented, the tar residues are screened through the leakage plate and the drainage plate and then drained to the crushing barrel to be crushed, the crushing precision is improved through batch crushing, and the crushing effect is better.

The utility model relates to a guiding filtering type tar filter which comprises a box body and a base located at the bottom of the box body, a plurality of supporting legs are installed at the bottom of the base, an air inlet is formed in the middle of the right side of the box body, an air outlet is formed in the middle of the left side of the box body, and a filtering assembly is installed in the box body. According to the utility model, by virtue of the guide plates which are obliquely distributed, large tar particles can be conveniently and better blocked, and the large tar particles can be conveniently and better settled on the filter screen below.

The invention discloses a modified pitch production process based on medium and low temperature coal tar heavy components, and relates to the technical field of modified pitch, the modified pitch production process comprises the following steps: raw material pretreatment: filtering and centrifuging medium and low temperature coal tar; hydrotreating: mixing the primary tar and a hydrogen-donor solvent according to the mass ratio of 1: (0.3-0.5), and adding a catalyst for hydrocracking reaction to obtain a hydrogenated product; thermal polycondensation reaction: separating heavy components in the hydrogenation product by adopting reduced pressure distillation, and feeding the heavy components into a two-stage thermal polycondensation reactor to generate a modified pitch intermediate; and gas-liquid separation: enabling the modified pitch intermediate to sequentially pass through a high-temperature cyclone separator, a condensation system and a supercritical extraction tower, and separating out light oil gas, a medium fraction and a modified pitch product. When the production process provided by the invention is adopted to treat the medium and low temperature coal tar, a cross-linking agent does not need to be added, so that the content of quinoline insoluble substances is reduced to 5-12%, and the softening point reaches 240-280 DEG C.

The present invention belongs to the technical field of coal chemical processing, and discloses a coal hydrogasification furnace system and a hydrogasification method of a liquid slag removal moving bed. In the hydrogasification system of the present invention, the gas outlet of the hydrogasifier is sequentially connected to the air inlet of the hydrogen membrane separator through a pressure reducing tank, a chilled water scrubber, and a gas-liquid separator. A hydrogen outlet and a methane-rich outlet are provided on the hydrogen membrane separator, wherein the hydrogen outlet of the hydrogen membrane separator is divided into two paths and connected to the second air inlet and the third air inlet of the hydrogasifier, and the pressure reducing tank, the chilled water scrubber and the liquid outlet of the gas-liquid separator are all connected to a tar collector. The hydrogasification method of the present invention can realize the controllable product components in the process of stabilizing the hydrogasification of coal, enhance the adaptability of raw materials and the diversity of products, and the methane yield and the yield of high light aromatics (BTX, PCXN) are high.

This invention discloses an integrated device for coal tar separation and recovery and electrostatic precipitator in coal gangue decarbonization tail gas, belonging to the field of flue gas treatment technology. It includes a dust collector, a coal tar separation and collection hopper, a radial flow rotary disc tar collector, and an electrostatic precipitator unit. The radial flow rotary disc tar collector is installed in the coal tar separation and collection hopper and includes an inner air-flowing central pipe, an outer pipe, multiple hollow collection discs, and a rotation drive assembly. A jacket is formed between the inner air-flowing central pipe and the outer pipe for introducing a heat exchange medium. The inner cavity of the hollow collection discs communicates with the jacket. A radial exhaust channel for tail gas is provided on the inner air-flowing central pipe. During operation, the heat exchange medium is switched to keep the disc surface at a low temperature during the condensation and collection stage, where tar in the tail gas condenses and adheres to the disc surface. During the desorption and regeneration stage, the heat exchange medium is switched to a high temperature and rotates at high speed, using centrifugal force to throw the tar out and collect it. This achieves anhydrous separation and resource recovery of tar, avoiding tar contamination of the electrostatic precipitator unit.

The invention discloses a multi-energy coupling submerged arc furnace tail gas carbon capture and efficient utilization system which comprises a tail gas purification and pretreatment subsystem used for conducting step-by-step purification treatment on tail gas of a high-temperature submerged arc furnace to remove dust, tar and sulfide; the power generation and waste heat recovery subsystem is used for receiving and storing the purified tail gas, generating power by using the tail gas and recovering waste heat of flue gas generated in the power generation process to generate steam; the alcohol amine method carbon capture subsystem is used for capturing CO2 in the flue gas discharged by the power generation and waste heat recovery subsystem, driving an amine liquid regeneration process by using steam generated by the power generation and waste heat recovery subsystem, and finally outputting purified liquid CO2; and the control system is based on a programmable logic controller or a distributed control system, realizes full-process parameter monitoring and dynamic optimization, and coordinates energy and material flow among the subsystems.

The utility model belongs to tar production processing technical field relates to a kind of tar intermediate tank body including intermediate tank body, feed pipe is equipped on the intermediate tank body, feed pipe is connected with external tar supply pipe, the lower end of intermediate tank body is rotatably installed with conical discharge pipe, driving assembly that is compatible with conical discharge pipe is equipped on the intermediate tank body, the inner wall of conical discharge pipe is equipped with extruding piece, extruding piece is helical, discharge pipe is rotatably connected in the lower end of conical discharge pipe, discharge pipe is connected with external tar depot, conical discharge pipe outside is equipped with heating assembly. The utility model is discharged to internal tar by setting conical structure's conical discharge groove in the lower end of its intermediate tank body, so that it can utilize gravity to accelerate material to slide down, compared with flat bottom, can reduce the retention area of tar in tank bottom, avoid deposition dead angle, while its inside is also equipped with helical extruding piece, rotate with conical discharge pipe, push tar to discharge port, further improve the discharging efficiency of the device.

The utility model discloses a carbonization and activation system for preparing a coal pitch-based porous material, which comprises a high-pressure gas cylinder for outputting a gas source, a gas output end in the high-pressure gas cylinder is connected with an input end of a tubular reactor after being decompressed, and a tail output end of the tubular reactor is connected with an input end of a condenser through a heat tracing pipeline; the bottom output end of the condenser is connected with the product discharge system, the top product output end of the condenser is connected with the adsorption and desorption system, and the top output end of the adsorption and desorption system outputs exhaust gas. The device has the structural characteristics of preventing equipment from being blocked and treating polluted tail gas.

The invention relates to the technical field of stemming refractory materials, and discloses an expansion iron mouth type anhydrous stemming for a blast furnace of more than 2000 cubic meters. The expansion iron mouth type anhydrous stemming comprises the following components in percentage by mass: 3-4% of high-temperature asphalt particles, 13-20% of ferro-silicon nitride, 10-13% of clay, 0.5-2% of carbon black, 3-5% of pyrophyllite, 31-39% of alumina clinker, 13-18% of silicon carbide, 5-7% of coke powder, 1-3% of polyethylene glycol and 12-13% of tar. According to the method, polyethylene glycol 200 is used as a binding agent, the characteristic that the polyethylene glycol 200 forms curing strength at 250-350 DEG C is utilized, the polyethylene glycol 200 and beta resin in high-temperature asphalt powder complete temperature relay to form carbon coke, a balling drum is rapidly stabilized within 15-30 minutes of gun pressing, and the iron notch depth is increased; according to the invention, the problem of strength of the stemming at 250-350 DEG C is effectively solved, good opening strength and enough iron notch depth are realized, the application effect on 2650 m < 3 > and 4000 m < 3 > blast furnaces is good, and the iron notch depth is respectively prolonged by 0.2 m and 0.4 m.

The utility model relates to the technical field of tar dehydration, and provides a tar dehydration device which comprises a heating barrel, sealing plates, a stirring mechanism and an opening and closing mechanism, the heating barrel is provided with a feeding port and two discharging ports, the two discharging ports are both rotatably connected with the sealing plates, the stirring mechanism is arranged in the heating barrel and used for stirring and scraping coal tar, and the opening and closing mechanism is arranged in the heating barrel. The opening and closing mechanism is arranged on the heating barrel and used for controlling the two sealing plates to be opened and closed, and the stirring mechanism comprises a stirring frame, a scraping plate, a transmission assembly and a driving assembly.By means of the technical scheme, the problems that in the related technology, due to the fact that coal tar is thick and is prone to adhering to the interior of the device, discharging is inconvenient, discharging is not thorough, and the coal tar cannot be discharged easily are solved. And the practicability is reduced.

The invention relates to the technical field of oil shale production, in particular to a method for improving the recovery rate of tar in gas of a venturi tower, and aims to solve the problem that in the gas conveying process of the venturi tower at present, due to the fact that the temperature of a pipeline is too high, light oil gas is usually very volatile, and finally the oil recovery rate is affected. According to the method, a plate type heat exchanger is additionally arranged at the rear end of an air cooler ring in series, treated coal mine water or tap water is used as a cold source to cool cold ring circulating water again, the temperature of the cold ring circulating water is reduced, the cold ring circulating water enters a rotational flow plate tower to wash coal gas, the temperature of the coal gas is effectively reduced, and the temperature of the coal gas is effectively reduced through real-time adjustment of a PLC temperature control system. And the temperature of the coal gas can be reduced to an ideal temperature required by oil catching of the high-voltage electrostatic oil catcher, so that oil-gas condensation and separation are effectively promoted, and the oil recovery rate is greatly improved while the cyclic utilization rate of mine water is increased.

The utility model relates to the technical field of tar residue treatment, in particular to a tar residue sealing and drying treatment device, which comprises a base, a bracket fixed on the base, a rolling ring arranged on the bracket, an outer cylinder rotationally connected in the rolling ring and an oil discharge port arranged on the outer cylinder, the first-stage driving assembly is installed on the base, the centrifugal assembly is installed on the outer cylinder, the second-stage driving assembly is installed on the outer cylinder, the cleaning assembly is installed on the centrifugal assembly, and the outer cylinder, the centrifugal assembly and the cleaning assembly rotate with the overlapped central axis as the axis; according to the utility model, the cleaning assembly is synchronously driven to operate by the same power source for driving the centrifugal assembly to operate, so that a small amount of tar residue adhered to the centrifugal assembly can be removed while the tar residue is separated and dried, the tar residue enters a drying treatment state again, and the drying degree and the drying efficiency of the tar residue are ensured.

A tar residue box water sealing device comprises a cover plate fixedly arranged at the bottom of a residue outlet pipe, a first upper sealing frame fixedly arranged at the bottom of the cover plate and a first lower sealing frame arranged on the periphery of a residue inlet of a tar residue collecting box, and a first water storage tank used for storing water is formed between the first lower sealing frame and the residue inlet. A water inlet pipe communicated with the interior of the water storage tank is arranged at the bottom of the first lower sealing frame, the water inlet pipe is detachably connected with a first connecting pipe through a first connecting assembly, the first connecting pipe is connected with an external water supply assembly, the water supply assembly is used for injecting water into the first water storage tank, and the bottom end of the first lower sealing frame is inserted into water in the first water storage tank. The water inlet pipe is firmly connected with the first connecting pipe, the situation that the first connecting pipe is separated from the water inlet pipe due to vibration of a pipeline is prevented, water resources are prevented from being wasted due to the fact that water flows out of the first water storage tank, and harmful gas is prevented from escaping.

This invention discloses a process for controlling the water content of tar before the dehydration distillation step in a tar distillation unit, comprising the following steps: S1, raw tar is pumped from a large tar tank to a working tar tank via a tar delivery pipeline. The water content of the raw tar is detected by a moisture meter on the tar delivery pipeline, and based on this, it is determined whether the raw tar should be returned to the tar centrifugal dehydration and slag removal system; S2, the raw tar in the working tar tank is pumped to the tar distillation unit for processing via the working tank outlet delivery pipeline. The water content of the raw tar is detected by a moisture meter on the working tank outlet delivery pipeline, and it is determined whether the raw tar in the working tar tank should be drained. This invention can further reduce the water content of tar before the dehydration distillation step in the tar distillation unit, thereby reducing the production load of the tar dehydration distillation step.

The utility model discloses a continuous graphitization furnace spray tower tar separation system which comprises a spray tower, an upper-layer liquid outlet valve is installed in the middle of the spray tower, and a bottom-layer liquid outlet valve is installed at the lower end of the spray tower. The layering condition of tar and water is visually displayed, accurate operation is facilitated, accurate positioning of the top end oil outlet pipe and the bottom end water outlet pipe is achieved through cooperation of the air cylinder and the connecting rod, tar and water with different densities are effectively separated and collected, tar can be collected, the separated water is recycled through the backflow pipe for cleaning of the spray tower, and the water recycling effect is good. According to the continuous graphitization furnace spray tower cleaning device, water resources are saved and recycled, emission of VOC and generation of waste water in the cleaning process of a traditional continuous graphitization furnace spray tower are reduced, the operation difficulty is lowered, and the operation safety is improved.

The invention relates to a tar residue box lifting device and a working method thereof. The tar residue box lifting device comprises a hoisting frame and a lifting device, a lifting slide rail and a walking guide rail are arranged in the hoisting frame; during hoisting, the tar residue box is connected with the lifting device through a steel wire rope and ascends and descends along the lifting channel; a turnover guide rail is arranged in the middle of the lifting channel, and the tar residue box can move to a batching position along the turnover guide rail and the walking guide rail. According to the invention, the lifting device is matched with the lifting slide rail and the walking guide rail, so that the operations of lifting, descending, transversely moving to a batching position and the like of the tar residue box are realized, the working efficiency is greatly improved, and the labor intensity is reduced; the tar residue box is in a closed state in the moving process, so that no pollution is caused to the environment, the safety production coefficient and the environmental protection level of a factory are improved, and a powerful guarantee is provided for normal production.

The utility model discloses an automatic tar discharging system of a clarifying tank. The automatic tar discharging system comprises a tar pipeline, a temperature measuring instrument, a moisture analyzer and a pipeline type flow meter, an inlet of the tar pipeline extends into the clarifying tank, and the moisture analyzer and the pipeline type flowmeter are mounted on the tar pipeline; the thermodetector extends into the clarifying tank, and a plurality of temperature measuring points are arranged on the thermodetector; an electric valve is further arranged on the tar pipeline, and the electric valve, the thermodetector, the moisture analyzer and the pipeline type flowmeter are all electrically connected with the controller; the automatic tar discharging system of the clarifying tank can solve the problems that the tar content in ammonia water exceeds the standard and the moisture content in tar exceeds the standard, and realizes automatic tar discharging in the whole process.

The invention relates to the technical field of tar residue treatment, in particular to mechanical residue removing equipment and process based on a tar residue storage tank, the residue removing equipment comprises the storage tank, a mixture conveying pump, a production unit and a guarantee unit, the mixture conveying pump is an intelligent variable frequency pump, and an outlet of the storage tank is connected with the input end of the mixture conveying pump; a flow detection module is mounted at the joint of the mixture conveying pump and the storage tank and is used for monitoring the flow of the tar residue mixture in real time and feeding back a signal to a control system of the mixture conveying pump; the output end of the mixture conveying pump is connected with the production unit, and the production unit is provided with two output ends, namely a solid output end and a liquid output end; the liquid output end is connected with the guarantee unit, and the guarantee unit comprises a showering system and a steaming and blowing system; the viscosity of the tar residues in the storage tank is greatly reduced through intermittent steaming and blowing softening and synchronous ammonia water spraying, the mixture conveying pump is smooth in pumping, and the problems that the tar residues in the storage tank are left and cannot be cleaned thoroughly are solved.

The invention relates to a tar dry residue blending, discharging and mixing device and method. The tar dry residue blending, discharging and mixing device comprises a tar residue box, a belt conveyor, a connecting rod pushing and discharging mechanism and a plough collecting and mixing mechanism. A tar residue box is arranged above the belt conveyor at the downstream of the coal bunker; the connecting rod residue pushing and discharging mechanism consists of a connecting rod driving motor, a crank, a connecting rod and a push rake, the push rake is arranged at the bottom of the tar residue box, and a plurality of push rake turning plates are longitudinally arranged on the push rake; and the mixed coal ploughing and collecting mechanism is arranged below the tar residue outlet and comprises a front coal ploughing plate and a rear coal collecting plate which can rotate in a lifting manner. The connecting rod slag pushing and discharging mechanism is adopted, the internal space of the tar residue box is not occupied, quantitative slag discharging of the tar residue box is achieved, meanwhile, coal blending operation can be achieved in cooperation with the belt conveyor and the plough collecting and mixing mechanism, meanwhile, pollution to equipment and the environment in the tar residue conveying process is avoided, operation is convenient, and the automation degree is high.

The utility model relates to the technical field of filtering devices, and discloses a tar residue filtering device which comprises a filtering box, a feeding pipe fixedly penetrates through the top end of the filtering box, two partition plates are fixedly connected to the inner wall of the filtering box, the two partition plates are located on the same vertical plane, and a distance is reserved between the two partition plates. A plurality of heating plates are fixedly connected between the partition plate on the lower side and the filter box and are obliquely arranged; through structures such as a heating plate, a four-way valve, a pipeline, a communicating plate and a nozzle, the effects of drying tar residues, improving drying efficiency, reducing generation of peculiar smell and protecting the environment are achieved, and the problems that in the using process of a traditional device, the tar residues generate peculiar smell, the surrounding environment is damaged by generation of the peculiar smell, and the environmental pollution is caused are solved. And the generated tar residue cannot be directly utilized, so that the resource waste is caused.

The application discloses a tar-containing biomass gasification gas MILD combustion system carbon smoke detection method, and relates to the technical field of renewable low-carbon energy utilization and carbon smoke emission control. The application comprises the following steps: S1, installing a tar-containing biomass gasification gas MILD combustion system; S2, installing a carbon smoke detection system; and S3, detecting a carbon smoke generation process. The application realizes fuel supply of the tar-containing biomass gasification gas through a controllable mixing evaporator, guarantees that the tar participates in combustion in a gaseous form, detects the whole carbon smoke generation process under the MILD combustion by combining a thermal migration sampling system and an optical diagnosis system, solves the fuel supply problem caused by the tar, realizes the MILD combustion of the tar-containing biomass gasification gas, and further provides an effective detection method for the whole carbon smoke generation process under the MILD combustion, and provides a solution for related experimental research.

The application discloses a method for preparing coal-tar pitch-based porous carbon by using double-salt compounds (K2CO3 and Na2CO3) and potassium hydroxide and application thereof. The pore diameter of the material activated by KOH is adjusted by adding K2CO3 and Na2CO3, and the sputtering and eruption of the sample in the activation process is avoided, and the equipment is not corroded. The application comprises the following steps: after coal tar that is crushed is uniformly mixed with an activating agent, simple one-step activation is carried out at high temperature, wherein the specific surface area of the porous carbon material can reach about 2000 m 2 / g, and the pore volume is between 0.98 and 1.29 cm 3 / g. When the porous carbon material is used as an electrode material of a super capacitor, the material shows high specific capacitance and good rate performance. The application provides a preparation method of high-specific-surface-area porous carbon, and the reaction process is mild.

The application discloses a super-large triad central tube type rotating bed gasification furnace, which comprises a hearth with a gasification section and a dry distillation section, and the wall part of the hearth is provided with an annular channel extending in the circumferential direction; a triad central tube assembly is arranged at a relatively upper position in the dry distillation section and comprises three array tubes arranged in a circumferential array with the hearth central axis as a reference and a flow collecting mechanism connected to the top of the three array tubes. The triad central tube realizes multi-point uniform gas collection and primary separation, the triad structure guarantees uniform radial heating of the dry distillation section, reduces tar generation from the source, and then the gap and the annular channel are used to realize forced backflow of heavy tar, uncompletely combusted fine carbon particles and fly ash to the gasification section combustion chamber for secondary cracking, thereby reducing the tar content of the outlet coal gas, the array tube dispersion reduces the inlet flow rate, effectively reduces the fly ash entrainment in the coal gas, the uniform gas extraction point optimizes the bed layer gasification agent distribution, and the carbon conversion rate is effectively improved.

The invention belongs to the field of biomass gasification tar measurement, and relates to a method for measuring tar content in a pressurized fluidized bed biomass gasification process, which comprises a tar sampling device and content measurement. The sampling device comprises a stop valve, a sampling pipe, a drying pipe, a sampler, a pressure reducing valve, a cooling device, a wet gas flowmeter and a pressure gauge, and can realize constant-speed sampling under high-temperature and high-pressure conditions. The measuring method is based on the measuring principle of a filter membrane weighing method, the tar content and the dust content are successfully measured separately, accurate measurement of the tar content is achieved, operation is easy, the measuring cost is low, and industrial practical application is facilitated.

The present application belongs to the field of biomass gasification tar measurement, and relates to a method for measuring tar content in a pressurized fluidized bed biomass gasification process, comprising a tar sampling device and content determination. The sampling device comprises a stop valve, a sampling tube, a drying tube, a sampler, a pressure reducing valve, a cooling device, a wet gas flow meter and a pressure gauge, and can realize constant-speed sampling under high-temperature and high-pressure conditions. The measurement method is based on the filter membrane weighing method measurement principle, successfully separates the tar and dust content for measurement, realizes accurate measurement of the tar content, and is simple to operate, low in measurement cost and beneficial to practical application in industry.

The invention provides a production process for continuously preparing an efficient coal water slurry additive from styrene tar. The production process is mainly used for increasing the concentration of coal water slurry in a gasification device. The continuous production process comprises multi-stage high-pressure sulfonation, hydrolysis, neutralization, solvent recovery and the like. The coal water slurry additive with high sulfonate radical content (15-25%) prepared by the process can improve the slurrying concentration of coal water slurry (concentration is increased by 2-3%), especially the coal slurry concentration of low-rank coal.