298 results about "Dry grinding" patented technology

The invention relates to the technical field of laser cutting machining, in particular to a cutting device for forge piece machining, which comprises a worktable, a transmission rotating shaft for conveying pipes is mounted at the upper end of the worktable, a first motor is mounted at the rear end of the worktable, and a cleaning mechanism for pretreating the pipes is mounted at the front end of the worktable; a bevel conveying frame is fixedly connected to the rear end of the workbench, a chamfering mechanism used for polishing the round pipe is installed on the inner side of the bevel conveying frame, through the synergistic effect of a heating plate and a friction plate, the heating plate is attached to the curved surface of the pipe in a self-adaptive mode through a second spring, and an oxide layer is heated to the softening temperature; through cooperation with circumferential grinding of a silicon carbide friction plate, the removal rate can reach 98% or above, the problem of scrap residue in traditional dry grinding is avoided, and it is ensured that the two sets of rotating plates clamp the pipe at the synchronous rotating speed through the rotating plate synchronous closing technology and the design of the 1.2-time tooth number ratio of a fourth gear and a fifth gear.

The utility model belongs to the field of photovoltaic modules, and particularly relates to a photovoltaic module cleaning device which comprises a cleaning module composed of a driving mechanism, a cleaning mechanism and a reversing mechanism. Under the control of the reversing mechanism, only the spraying rod facing one side of the advancing direction sprays water for cleaning each time, that is to say, the front of the wiping block is always subjected to the operation of spraying water for wetting when the wiping block moves along with the moving seat, and the use is convenient and flexible; the adaptive starting of the two spraying rods can be automatically started and stopped according to the moving direction of the moving seat, the automation degree is high, the phenomenon that a wiping block and a photovoltaic panel are damaged due to dry grinding is avoided, and the problem that when an existing spraying rod and an existing wiping rod move in a reciprocating mode, it cannot be guaranteed that a clean water source is sprayed in front of the wiping rod all the time is solved; the wiping rod and the photovoltaic panel are easily subjected to dry grinding cleaning, and the surface of the photovoltaic panel is damaged.

The invention relates to the field of tungsten carbide, and provides a preparation method of wear-resistant tungsten carbide powder in order to solve the problem that it is difficult for existing tungsten carbide to ensure high compactness while ensuring high wear resistance of a coating, and the preparation method comprises the steps that S100, by weight, tungsten carbide, cobalt powder, polyethylene glycol and alcohol are put into a ball mill to be subjected to ball milling, and slurry is obtained; s200, granulating the slurry through an atomization drying tower to obtain mixed powder; s300, sintering the mixed powder to obtain a powder block; s400, the powder blocks are made into wear-resistant tungsten carbide powder through a dry grinding machine; the tungsten carbide comprises 25 wt%-35 wt% of a first component, 28 wt%-32 wt% of a second component and the balance of a third component. The average particle size of the first component is 0.4-0.6 [mu] m, the average particle size of the second component is 0.9-1.2 [mu] m, and the average particle size of the third component is 2.5-2.8 [mu] m; the polyethylene glycol comprises a polymer of which the molecular weight distribution is 2000-20000, and the polymer of which the molecular weight distribution is 15000-20000 accounts for 50%-60%. Through grading of the tungsten carbide raw material, after the prepared tungsten carbide powder forms a coating, the coating has the characteristics of wear resistance and high compactness.

The invention discloses a fly ash pretreatment method and a preparation method and application of an anti-corrosion and wear-resistant coating, and relates to the technical field of fly ash treatment, and the method comprises the following steps: s1, dispersing inferior fly ash in water, and then uniformly stirring to form ore pulp; s2, an emulsifying agent is dissolved in water, a collecting agent is added under stirring, and then an O / W type emulsifying collecting agent is obtained; s3, the prepared O / W type emulsifying collecting agent and foaming agent are added into the ore pulp, first-stage flotation solid removal treatment is conducted after sufficient stirring, and first-stage solid-removed fly ash is obtained; s4, drying the obtained first-stage solid-removed fly ash, and then carrying out second-stage electric separation solid-removed treatment to obtain second-stage solid-removed fly ash; and s5, adding a modifier and water into the obtained secondary solid-removed fly ash, carrying out wet grinding, taking out the fly ash after the modifier fully reacts with the fly ash, taking out the fly ash, drying the fly ash, and carrying out dry grinding to obtain the fly ash subjected to chambering modification. Therefore, the problem of incapability of direct resource utilization due to excessive impurity content of fly ash in the power plant in the prior art is avoided.

The invention relates to the field of tungsten carbide, and provides a preparation method of composite tungsten carbide powder in order to solve the problem that in the preparation process of existing tungsten carbide powder, due to concentrated volatilization of a binder during sintering, the morphology of the powder cannot be effectively kept. 55-65 parts of tungsten carbide, 5-9 parts of cobalt powder, 1-3 parts of polyethylene glycol and 18-24 parts of alcohol are put into a ball mill to be subjected to ball milling, and slurry is obtained; s200, granulating the slurry through an atomization drying tower to obtain mixed powder; s300, sintering the mixed powder to obtain a powder block; s400, the powder blocks are made into composite tungsten carbide powder through a dry grinding machine; the polyethylene glycol comprises a polymer with the molecular weight of 2000 to 20000. The molecular weight of the polyethylene glycol is regulated and controlled, so that the polyethylene glycol not only can keep a good bonding effect, but also can be volatilized in batches during sintering, the morphology of mixed powder is kept, the defects of a sintered product are reduced, and the performance of a final product is improved.

The utility model discloses a pit vacuum pump which comprises a vacuum tank provided with a connecting pipe, the connecting pipe is provided with an inserting pipe, and a static ring is arranged in the inserting pipe in a sliding mode. A movable ring is rotationally arranged in the liquid inlet pipe; the sealing device further comprises springs which are symmetrically arranged on the static ring, and the static ring is attached to the end face of the movable ring under pushing of the springs. According to the pit vacuum pump provided by the utility model, through the arrangement of the vacuum tank, the phenomenon that the self-suction force of the pump body is insufficient is eliminated, the overall suction effect is improved, meanwhile, the air binding phenomenon and the dry grinding condition of equipment are avoided, vibration is reduced, the operation period is prolonged, and pump filling during first-time starting is realized; pumping and exhausting are not needed during each start and stop, so that time and manpower are greatly saved.

The invention provides modified composite light calcium carbonate as well as a preparation method and application thereof, and belongs to the technical field of functional inorganic powder. The preparation method comprises the following steps: mixing lime milk slurry with water to obtain slurry, and then adding a dispersing agent and a crystal form control agent to react in a carbon dioxide atmosphere to obtain light calcium carbonate powder; the preparation method comprises the following steps: crushing calcite raw ore, carrying out dry grinding by a ring roller mill to obtain calcium carbonate coarse powder, adding water and part of a pre-dispersing agent, pulping to obtain calcium carbonate slurry, adding the rest of the pre-dispersing agent and a silicon source, and sequentially carrying out grinding and spray drying to obtain superfine heavy calcium carbonate powder; mixing the light calcium carbonate powder, the superfine heavy calcium carbonate powder and the composite modifier, and modifying to obtain the modified composite light calcium carbonate. The modified composite light calcium carbonate prepared by the invention not only retains the regular crystal structure of light calcium carbonate, but also has the advantages of small particle size, high 2-micron content and large specific surface area of superfine heavy calcium carbonate.

The utility model relates to the technical field of grinding machine screens, in particular to a dry grinding screen which adopts a screen body, the screen body is provided with a plurality of longitudinally-arranged long-strip filter holes, and the long-strip filter holes comprise narrow-slit long-strip filter holes and wide-slit long-strip filter holes which are sequentially communicated from the front face of the screen body to the back face of the screen body. The slit width of the narrow slit long-strip filtering holes is smaller than that of the wide slit long-strip filtering holes, materials meeting the particle size requirement are screened out through the long-strip filtering holes, the long-strip filtering holes are longitudinally formed, in the actual grinding process, under the action of materials / grinding media, the materials in the long-strip filtering holes are easier to remove, blockage caused by material accumulation in the long-strip filtering holes is avoided, and the service life of the long-strip filtering holes is prolonged. And the screen can screen out materials meeting the particle size requirement in time, and the grinding efficiency is improved. Materials are sequentially discharged along the narrow-slit long-strip filtering holes and the wide-slit long-strip filtering holes during discharging, the narrow-slit long-strip filtering holes are used for screening the materials, and then the materials enter the wide-slit long-strip filtering holes to be discharged, so that the situation that the whole long-strip filtering holes are blocked due to material accumulation is better avoided.

The invention discloses an architectural ceramic wetting and powdering production system, which relates to the technical field of ceramic production systems, and comprises two main process links of dry grinding and fine powder wetting, and wet ball milling and fine powder wetting. Wherein dry grinding comprises a raw material storing and batching device, raw materials in the raw material storing and batching device are classified through dry and wet raw materials, hard stone raw materials are fed into a column crusher to be crushed, and a vertical mill or a dry ball mill is selected according to the comprehensive moisture difference of the raw materials in the formula; a feeding machine in the wet ball milling is communicated with a wet ball mill, the wet ball mill is communicated with a slurry tank, and powder in the slurry tank is treated to obtain dry fine powder; fine powder wetting comprises a wetting tower, powder of the wetting tower is fed into a drum screen, and the drum screen feeds the powder into a self-flowing type powder waking bin. According to the invention, the selection of the vertical mill or the dry ball mill can be determined according to the water content in the raw material formula, and the dry fine powder is wetted by the wetting tower, so that compared with a traditional wetting mode, the wetting tower can more uniformly wet the dry fine powder.

The invention discloses a hydrogen storage alloy and a preparation method thereof, relates to the technical field of metal functional materials, and solves the problems of high reaction temperature and low hydrogen absorption and dehydrogenation rate of a magnesium-based hydrogen storage material in the prior art. The prepared hydrogen storage alloy comprises the following alloy components in parts by mass: 5-15 parts of nickel, 2-8 parts of yttrium, 2-8 parts of ytterbium, 68.8-91 parts of magnesium and 0-0.2 part of impurities. A magnesium ingot, a magnesium-yttrium alloy and a magnesium-ytterbium alloy are melted, then magnesium-nickel alloy is added, stirring is conducted till the magnesium-nickel alloy is melted, standing is conducted, and casting is conducted to obtain a hydrogen storage magnesium alloy cast ingot; the method comprises the following steps: crushing a hydrogen storage magnesium alloy cast ingot, loading into a stainless steel ball milling tank for dry milling, and adding a solvent into the tank body for wet milling after the dry milling is finished; and drying to obtain the magnesium alloy flaky powder. According to the invention, multiphase cooperation, structure regulation and interface optimization of multiple elements are utilized, so that the hydrogen absorption and desorption performance of the hydrogen storage material is obviously enhanced.

The invention discloses dual-drive dry grinding equipment, which belongs to the field of grinding equipment and comprises a grinding cylinder, two ends of the grinding cylinder are respectively and fixedly provided with a grinding cylinder rotating shaft, a grinding rotor is arranged in the grinding cylinder, two ends of the grinding rotor are respectively and fixedly provided with a rotor transmission shaft, and the rotor transmission shafts and the grinding cylinder rotating shafts are concentric and non-coaxial and can relatively independently rotate. According to the grinding equipment, in the grinding process, the grinding cylinder can be rotated to drive a grinding medium to roll, the grinding efficiency is greatly improved, meanwhile, the grinding medium is evenly stressed on the inner wall of the grinding cylinder to shear and collide, generation of static electricity is reduced, and therefore hardening and accumulation of powder on the inner wall are reduced, and the powder is more evenly ground; by rotating the grinding rotor, higher power is provided for the grinding medium in the grinding inner cavity, so that the grinding efficiency is improved again, the rotor transmission shaft and the grinding cylinder rotating shaft are of a concentric and heteroaxial structure, the grinding cylinder and the grinding rotor can rotate and operate at different rotating speeds, the grinding device is suitable for operation under different working conditions, and the error-tolerant rate is higher.

The invention belongs to the field of lithium battery recycling, and particularly relates to a method for recycling lithium in lithium iron phosphate battery black powder. The method comprises the following steps: sieving the lithium iron phosphate battery black powder with a 200-mesh sieve, oxidizing the powder with oxygen for 20-40 minutes to obtain powder a; dry ball milling: weighing phosphoric acid salt of sodium, the powder a and potassium superphosphate, mixing, and carrying out dry milling for 2-3 hours to obtain powder b; iron removal: dissolving the powder b subjected to dry grinding in water, and filtering to obtain a solid phase a and filtrate a; adding 0.1-0.3 wt.% of alkali into the filtrate a, and filtering to obtain filtrate b; leaching out lithium; adding an aqueous solution of saturated soluble carbonate into the filtrate b obtained in the step S3, heating and concentrating, and filtering while hot; washing and enriching; and washing with hot water, filtering, and collecting a solid phase to complete lithium recovery. According to the method, lithium ions are replaced through potassium ions and sodium ions, mechanical ball milling and the oxidation effect of persulfate are matched, lithium is leached in a synergistic mode, corrosion to equipment is small, and meanwhile the leaching rate of lithium can reach 98% or above.

The invention relates to the technology of refractory materials, in particular to a process and system for producing alumina-based high-temperature synthetic materials, the system comprises a crushing unit, a dry grinding unit, a wet grinding unit, a mixing unit, a press unit, a drying kiln and a tunnel kiln, the drying kiln is connected with the tunnel kiln through a track, the crushing unit is connected with the dry grinding unit and the wet grinding unit, and the mixing unit is connected with the dry grinding unit and the wet grinding unit. The dry grinding unit and the wet grinding unit are respectively connected with the material mixing unit, the material mixing unit is connected with the press unit, the manipulator is arranged between the press unit and the drying kiln, the press unit performs automatic pressing, material distribution and brick discharging, the manipulator performs brick stacking according to programming, and the brick stacking vehicle sequentially enters the drying kiln and the tunnel kiln through the track. According to the method, the water content and the mixing ratio of the dry grinding powder and the wet grinding slurry are finely controlled, and the mixing means of the original process is improved, so that the production cost is lower, the quality of the obtained product is better, and the production efficiency of the alumina-based high-temperature synthetic material is effectively improved on the premise of energy conservation and emission reduction.

The invention discloses a dry grinding, automatic grading and thermochemical activation method for coarse ore powder, which comprises the following steps: 1) mixing limonite and specularite according to a ratio of 7: 3, and carrying out dry grinding to form embedded novel fine grinding iron ore powder; 2) dynamically drying for more than 28 seconds through a thermal medium at 450-550 DEG C to remove 1.5-6.5% of crystal water from materials entering a mill, promoting conversion of 10-30% of limonite phase into hematite, reducing the heat sensitivity and burning loss of the hematite, and improving the roasting performance of the pellets; (3) through dynamic drying-vertical roller milling integrated pretreatment, the surface activity and the surface energy of the coarse iron ore powder are improved under the action of a thermal medium and mechanical force; and (4) finished fine ground iron powder collected by the cloth bag powder collector is conveyed to a finished product bin for storage through a closed chute and a bucket elevator, is metered by a sealed belt weigher, is humidified by a humidifier and then enters an M1 belt to participate in pellet batching. According to the method, the adding proportion of specularite and limonite powder in pellet production is greatly increased, the wide caliber of pellet raw materials is achieved, and the raw material production cost of pellet ore is reduced.

The utility model relates to the technical field of dry grinding and dry separation of iron ore and similar processes, and particularly discloses a dry grinding and dry separation system which comprises an incoming material conveying system, a roller mill, a dynamic powder concentrator, a dry classification cabin and a fine powder collecting and conveying system. A discharging hole of the supplied material conveying system is communicated with a feeding hole of the roller mill; a discharging hole of the roller mill is communicated with a feeding hole of the dynamic powder concentrator; a coarse particle material outlet of the dynamic powder concentrator is communicated with a material inlet of the dry type grading cabin; an oversize coarse particle discharging opening of the dry type grading cabin is communicated with a feeding opening of the roller mill; and a fine powder discharge hole of the dynamic powder concentrator is communicated with the fine powder collecting and conveying system. Finished product materials with various particle sizes can be provided, and the requirements of customers for different finished product particle sizes are met; fine powder screened by the dynamic powder concentrator is collected by a dust collector and then is directly conveyed to a tailing discarding procedure, so that the handling capacity of the dry classification cabin is reduced; the use condition of the dry-type grading cabin is optimized, and the system flow is simplified.

The invention discloses a production method for producing low-alkalinity fluxed pellets from whole hematite limonite, which comprises the following steps: taking flue gas treatment by-product desulfurized fly ash and carbon-containing dedusting ash, feeding into a first batching bin, blanking according to a first preset proportion, feeding into a powerful mixer, mixing, and rolling at high pressure to obtain a first mixture; performing dry grinding or wet grinding on the hematite and limonite coarse powder to obtain hematite and limonite fine powder; the first mixture, hematite and limonite fine powder and bentonite are blanked according to a second preset proportion, and a second mixture is obtained; carrying out strong mixing and high-pressure roller milling on the second mixture, and pelletizing to form green pellets; and the green pellets sequentially enter a forced air drying section, an air draft drying section, a preheating section and a roasting section of a belt type roasting machine, and finally the all-hematite limonite low-alkalinity fluxed pellets are obtained. The method has the advantages that the pulverization phenomenon caused by the low bursting temperature of the drying section can be eradicated, the quality of green pellets is improved in the drying section, conditions are provided for liquid phase generation in the preheating and roasting sections, and the compressive strength of pellets is remarkably improved.

The invention discloses a magnetic suspension compressor energy feedback method and system, a compressor, a medium and a program product, and relates to the technical field of compressors, the magnetic suspension compressor energy feedback method comprises the following steps: collecting the real-time bus voltage of the compressor, and when the real-time bus voltage is lower than a preset cut-in voltage threshold, controlling the compressor to enter an energy feedback mode, in the energy feedback mode, a motor of the compressor is controlled to provide electric energy for a preset voltage controller; and inputting a preset bus reference voltage and the real-time bus voltage into a voltage controller, and controlling the voltage controller to output a motor quadrature-axis current to a bus capacitor of the compressor so as to supply power to a bearing controller. The bearing controller cannot be powered off after the magnetic suspension compressor is powered off, the dry grinding condition is avoided, and the operation stability of the compressor is kept.

The invention relates to the technical field of phosphorus chemical industry solid waste resource utilization, and particularly discloses a liquid triisopropanolamine feeding device for phosphorus slag micro powder dry grinding production, which comprises a liquid storage assembly, a metering conveying mechanism, a preheating mixing mechanism, a dry grinding machine butt joint assembly and an intelligent regulation and control module. The liquid storage assembly stores materials under the protection of nitrogen and at a constant temperature; the metering conveying mechanism achieves constant-temperature and accurate metering conveying of materials through a variable-frequency plunger pump, an electromagnetic flowmeter and a pipeline with a heat preservation heat tracing function. The preheating mixing mechanism atomizes liquid triisopropanolamine through an atomizing nozzle, and the liquid triisopropanolamine and phosphorus slag raw materials are forcibly mixed to be uniform in a heating cavity through a stirring assembly. The dry mill butt-joint assembly realizes sealed conveying of the mixed materials to the dry mill; and the intelligent regulation and control module is connected with and cooperatively controls each component. The problems of large metering error, high volatilization loss, non-uniform mixing and easy blockage in the prior art are solved, and the phosphorus slag grinding efficiency, the product quality and the system operation continuity are remarkably improved.

The invention relates to a high-temperature alloy-Ti (C, N) composite metal ceramic material and a preparation method thereof, and belongs to the technical field of metallurgy. The preparation method comprises the following steps that S1, high-temperature alloy powder and Ti (C, N) ceramic powder are subjected to dry grinding, ultrasonic dispersion, wet grinding and drying, and metal ceramic powder is obtained; and S2, the metal ceramic powder is subjected to two-way pressing, vacuum sintering and cooling, and the high-temperature alloy-Ti (C, N) composite metal ceramic material is obtained. The high-temperature alloy-Ti (C, N) composite metal ceramic material prepared by the method has excellent high hardness, obdurability and high-temperature resistance, has outstanding room-temperature and high-temperature mechanical properties, and can meet the strict requirements of extreme working conditions and high-speed cutting on the comprehensive properties of the material.

The present application relates to a kind of engine pre-oiling system and method, including main oil tank and auxiliary oil tank, main oil tank is sequentially connected with main oil passage by pipeline by oil pump;Auxiliary oil tank is connected with the outlet of oil pump by corresponding pipeline with main oil passage respectively, and the pipeline connected with the outlet of oil pump is equipped with first pre-oiling pump, and the pipeline connected with main oil passage is equipped with second pre-oiling pump, and heating device is equipped on auxiliary oil tank.By increasing auxiliary oil tank and the pipeline and oil pump matched, the oil passage pressure fluctuation when engine is started first or normally is used to inject lubricating oil into auxiliary oil tank, so that when the viscosity of engine oil is increased in low temperature environment, the lubricating oil in auxiliary oil tank can be heated by heating device and sent into main oil passage, to avoid the problem of dry grinding, lubrication and damage caused by the influence of oil viscosity in bearing region.

The utility model discloses a mechanical shaft seal self-flushing circulating cooling structure and a compressor comprising the mechanical shaft seal self-flushing circulating cooling structure, the mechanical shaft seal self-flushing circulating cooling structure comprises an oil separator, a cooling pipeline, an adapter, a mechanical seal sealing cavity and a U-shaped pipeline, the adapter is located at the top of the mechanical seal sealing cavity, and the U-shaped pipeline is located at the bottom of the mechanical seal sealing cavity. The two ends of the cooling pipeline are connected to the oil distributor and the adapter respectively and communicate with the oil distributor and the adapter, and the two ends of the U-shaped pipeline are connected to the adapter and the bottom of the mechanical seal sealing cavity respectively and communicate with the adapter and the mechanical seal sealing cavity. According to the sealing structure, solid particles can be prevented from being accumulated on the sealing surface, cooling liquid stays in the sealing cavity through self weight under the condition that the whole system is stopped, timely lubrication is brought to next starting, and a sealing material is prevented from being degraded due to dry grinding and overheating; and meanwhile, the operation flexibility is improved, and the cost is reduced.

1. Name of the designed product: automatic grinder (dry grinding type). 2. Use of the designed product: grinding of blades. 3. Design points of the designed product: in shape. 4. Picture or photo that best shows the design points: perspective view. 5. The bottom surface of the designed product is the part that is not easy to see or cannot be seen during use, and the top view is omitted.

The invention relates to a ruthenium-modified iron-based catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: carrying out wet grinding on iron powder, a carbon and nitrogen source and a solvent to obtain slurry, and drying the slurry to obtain a precursor; and carrying out dry grinding on the precursor and a ruthenium source, and calcining in a reducing atmosphere to obtain the ruthenium-modified iron-based catalyst. According to the ruthenium-modified iron-based catalyst prepared by the invention, a carbon-nitrogen layer is formed on the surface of Fe, then Ru loading is carried out, active hydrogen generated in the reaction process can be timely transferred to the surface of the carbon-nitrogen layer to be combined with electrons to form H2 during thermocatalytic synthesis of ammonia, and the poisoning problem of the catalyst is effectively relieved.

The present invention discloses an ABX3 perovskite composite electromagnetic wave absorption material and a preparation method, which belongs to the field of electromagnetic wave absorption material preparation. The first step is to prepare ABX3 perovskite by dry grinding, and then dry and heat treat it. The second step is to uniformly mix and compound the prepared ABX3 perovskite with carbon nanotube materials according to different mass ratios. The present invention adopts a solvent-free method to prepare ABX3 perovskite-type absorption material, which is in the form of irregular nanoparticles and forms a conductive network structure with carbon nanotubes. The suitable structure constructed in this way has a strong absorption effect on electromagnetic waves and has a wide absorption band. The material preparation method does not require toxic solvents, has simple synthesis equipment, low cost, few processes, high yield, and is suitable for large-scale preparation.

The utility model discloses a graphite ore dry-wet combined grinding system, which belongs to the field of graphite ore crushing and grinding processing, and comprises a ball mill, a spiral classifier and a feeding belt, the feeding belt is connected with a lifting machine, the lifting machine is connected with a roller type crushing and grinding machine, and the roller type crushing and grinding machine is connected with the spiral classifier. The elevator is used for conveying the graphite raw materials conveyed by the feeding belt into the roller type comminution mill; the number of the spiral classifier is at least one, the spiral classifier is used for primarily screening the ground materials, and unqualified materials are returned to the ball mill; according to the system, a grinding system combining dry grinding of a roller type comminutor material bed and wet grinding of a ball mill is adopted, efficient grinding of graphite ore is achieved, through the design of a buffering discharging pipe and a stirring bin of the roller type comminutor, the running stability of the mill is guaranteed, meanwhile, slurry-shaped materials to be subjected to water separation can be discharged, and the system can adapt to the graphite ore water separation process.

The invention provides a fault identification and processing method and control system for a high-pressure pump, and the method comprises the steps: a sensor assembly obtains the operation information of the high-pressure pump, and transmits the operation information to an MCU; the MCU determines the operation state of the high-pressure pump according to the operation information; wherein the operation state comprises a normal state, a no-load state, a bubble state and a blocking state; the MCU sends a normal instruction or a control instruction to the ECU according to the running state; and the ECU limits the operation of the high-pressure pump or controls the high-pressure pump to stop according to the control instruction. Dry grinding and high heat of the motor in a liquid-free cooling state are avoided, the temperature rise of the motor is effectively controlled, insulation aging or coil burning is avoided, and the service life of the motor is remarkably prolonged.

This invention provides a method for producing fine polyolefin powder in micrometer units, characterized by uniform particle shape, average particle size, and particle size distribution. [Solution] This invention relates to a method for producing polyolefin ultrafine powder and the polyolefin ultrafine powder produced thereby. Specifically, the method involves mixing and heating a polyolefin resin with a xylene mixed solvent to produce a polyolefin molten liquid, then cooling and crystallizing it, and then ultrafine grinding the crystallized reactant through a vacuum wet grinding step and a dry grinding step, in which wet grinding and drying are performed simultaneously with the solvent, thereby providing an ultrafine polyolefin powder with an average particle size of approximately 30 μm or less. A xylene mixed solvent is used as the mixed solvent for melting the polyolefin resin, and the ultrafine polyolefin powder produced thereby can be applied to general-purpose material fields such as construction, civil engineering, and chemical products, and has physical properties that are particularly advantageous for the manufacture of secondary battery electrodes.

The invention discloses a nitrogen-doped carbon catalyst based on weathered coal humic acid as well as a preparation method and application of the nitrogen-doped carbon catalyst. According to the method, weathered coal humic acid is used as a carbon precursor, the carbon precursor and a specific nitrogen source are mechanically ground and mixed according to the equal nitrogen proportion, and the nitrogen-doped carbon catalyst is prepared after high-temperature calcination and acid pickling. The catalyst is used for activating peroxymonosulfate (PMS) to degrade tetracycline, and under the conditions that the dosage of the catalyst is 0.2 g / L and the concentration of the PMS is 1.0 mM, the degradation rate of 20mg / L tetracycline in 30 minutes exceeds 85%. The synergistic effect of inherent trace iron in humic acid and an external nitrogen source is utilized, and high-activity sites are formed in situ in the pyrolysis process; dry grinding is adopted in the process, additional metal sources and solvents are not needed, low-cost and environment-friendly preparation of the efficient heterogeneous catalyst from waste resources is achieved, and a new material is provided for degradation of organic pollutants.

The present invention relates to the technical field of automobile repair and polishing equipment, and specifically to an explosion-proof automobile paint repair dry polishing device and dry polishing method. The device comprises a processing box, a polishing machine, a polishing sheet and an exhaust pipe, and the processing box is provided with a sealed door. The device can adsorb the dust generated by dry polishing through a filtering and collecting mechanism, and then adsorb the dust through an electrostatic roller. At the same time, the electrostatic roller can be moved laterally and up and down by a driving motor and an electric push rod, thereby adsorbing dust at different positions and heights. When the adsorption is good, the dust on the surface of the electrostatic roller can be swept by an output motor and a brush roller. At the same time, the water pump can be started to spray water mist with multiple spray nozzles, thereby reducing the resin dust and placing it in a collection box, thereby classifying and storing the dust, which is convenient for the later collection of metal dust for recycling.

The present application relates to a kind of centrifugal compressor, including shell, rotor, inner magnetic ring and outer magnetic ring, the rotor is arranged in the shell, the inner magnetic ring is arranged on the rotor, the outer magnetic ring is arranged on the shell, the outer magnetic ring is sleeved on the inner magnetic ring and with the inner magnetic ring in the radial direction of the rotor with gap, the inner circumferential surface of the outer magnetic ring and the outer circumferential surface of the inner magnetic ring on pole opposite.The centrifugal compressor of the present application, when the rotor bears external axial force, the axial force received by the rotor is balanced by the magnetic attraction force between the inner magnetic ring and the outer magnetic ring, at least part of the axial force acting on the rotor is cancelled, to avoid dry grinding of the gas floating thrust bearing on the rotor, reduce the heating condition of the gas floating thrust bearing, ensure the stability of the rotor under different working conditions of centrifugal compressor.