44results about How to "Reduce inspiratory volume" patented technology

The present invention relates to a superplastic forming method for the titanium plate specially used for the plate type heat exchanger, which belongs to the field of mechanical processing technology. The present invention comprises the following steps that spongy titanium is chosen to be the melted raw material; the spongy titanium is placed in a vacuum plasma smelting furnace to be directly cast into plate base; the plate base forms a plate of a thickness of 2.0 to 2.4 mm after the process of heating, hot rolling, acid and alkali washing; second heating, hot rolling and acid and alkali washing and annealing; the plate of a thickness of 2.0 to 2.4 mm after the annealing in the vacuum smelting furnace forms a titanium plate of a thickness of 0.5 to 0.6 mm after the process of cold rolling, cleaning, second annealing and cold rolling, acid and alkali washing and third annealing. The present invention adopts the process that the spongy titanium which contains oxygen, iron and nitrogen of comparatively high content is directly processed into the titanium plate base in the plasma smelting furnace and directly rolled into the plate without forging and pressing.

This invention is a ceramic grain reinforcing Al-base compound material and its preparation method, and relates to a Al-base alloy. Its components are: 2.5-15% TiN, 2.4-10%AIN, 4-6.5%Si, 0.5-1.5%Cu, 0.3-0.5%Mg, 0-0.8%Ni, 0-0.5%Ti, and the rest is Al, and the percentages are weight percentages; the preparation method adopts melt blending founding method, and the technique flow is: material matching-melting base body-adding reinforcing grains-melting-modifying treatment-pouring-heat treatment, and the size reinforcing grains is in the range of 5-10 mum, and the vacuum degree of the vacuum furnace is 1.3-1.6X10 to the power -3 Pa, the temperature is 670-800deg.C, the modifying agent is 1-18g / Kg compound material containing 1-6% Na nanometer Al alloy powder; the Al-base compound material of this invention has light weight, high modulus number, high intension, good heat-fast and wearable performances, and the preparation cost is low, the technique is simple and it can be industrially produced.

The invention belongs to the field of fire flooding process, in particular relating to a layered electric ignition method for multilayer gas injection of fire flood, comprising the following steps: (1) placing a gas injection tubular column in a fire flooding gas-injection well; (2) continuously injecting air into the gas injection tubular column; (3) determining a main gas-entry layer by means of a main gas-entry profile; (4) heating the air until the temperature of the air is above 450 DEG C, and ensuring the contents of the oxygen in tail gases of surrounding production wells to be less than or equal to 2%; (5) injecting high-temperature foams into the fire flooding gas-injection well, and when pressure increases 1-4Mpa, determining the main gas-entry layer by the means of the main gas-entry profile; (6) increasing the air injection amount by 30%, electrifying to heat the injected air until the temperature of the injected air is above 450 DEG C, and ensuring the contents of the oxygen in the tail gases of the surrounding production wells to be less than or equal to 2%; and (7) continuing to inject the high-temperature foams, ensuring the air injection intensity, and determiningthe main gas-entry layer by means of the main gas-entry profile when the pressure increases, as well as detecting the compositions in the tail gases of the surrounding production wells. According to the invention, the fire flood is utilized to realize multilayer combustion, multilayer effectiveness and high mining efficiency.

The invention provides a metal mold casting coating for an aluminum alloy thin-walled piece. The coating is prepared from refractory aggregate, adhesive and carrier liquid, wherein the refractory aggregate contains kieselguhr, corundum powder, titanium dioxide and asbestos powder; the adhesive is silica sol or anhydrous phosphate; the carrier liquid is industrial alcohol; and the coating comprises the following components in part by weight: 0.5 to 1 part of kieselguhr, 0.5 to 1 part of corundum powder, 1.5 to 3.5 parts of titanium dioxide, 3 to 7 parts of asbestos powder, 0.6 to 1 part of silica sol or anhydrous phosphate, and 20 to 60 parts of industrial alcohol. The invention also provides a preparation method for the coating; the method comprises the following steps of: putting the refractory aggregate and the adhesive into a container with proper size, stirring the refractory aggregate and the adhesive uniformly through manpower or a machine, pouring the industrial alcohol into the container, and stirring uniformly for later use. The invention finally relates to a coating method of the coating. When the coating is used, the temperature of a die is between 180 and 400 DEG C, and a coating with the thickness of 0.1 to 0.5 millimeter is coated on the surface of the die.

The invention discloses an explosion-proof ventilation device for underground engineering. The explosion-proof ventilation device for the underground engineering comprises a ventilation pipe and a fanmounted inside the ventilation pipe, the inner wall of the ventilation pipe is fixedly provided with an adjustment device for adjusting the rotation speed of the fan, a treatment box is fixed on theinner wall of the ventilation pipe, the side wall of the treatment box is provided with a ventilation groove in a penetrating mode, an L-shaped connecting rod is fixed on the inner wall of the ventilation groove, a rotating shaft is rotationally connected to the side wall of the connecting rod, and a plurality of rotating plates are fixed to the circumferential side wall of the rotating shaft. Theexplosion-proof ventilation device has the advantages that when the concentration of mashgas of an underground passage is relatively high, and air input by an air outlet pipe is not enough to reducethe concentration of the mashgas, a detector can emit an acousto-optic alarm, the emitted sound can be used for prompting a worker for prevention, the emitted flash can reduce the value of resistanceof a photoresistor, so that the attraction force of an electromagnet to an electricity connecting piece is increased, then the rotation speed of the fan is reduced, the air suction amount per unit time is reduced, then the concentration of the mashgas in the ventilation pipe is reduced, and explosion is avoided.

The invention discloses a pollution discharge drop shaft structure based on an internal circulation airflow pipe. The pollution discharge drop shaft structure comprises a vertical shaft and the internal circulation airflow pipe arranged in the vertical shaft, the inner circulation airflow pipe divides the vertical shaft into a water passing part and a non-water-passing air pipe part, the water passing part is connected with a water inlet pipe, the top of the inner circulation airflow pipe is lower than the bottom of the water inlet pipe, the bottom of the inner circulation airflow pipe is higher than the top of an outflow pipe, the inner circulation airflow pipe is used for guiding air to form inner circulation airflow in the airflow pipe, and the inner circulation airflow pipe is vertically hung in the vertical shaft through a fixing device and makes contact with the inner wall face of the vertical shaft. The invention further discloses a using method of the pollution discharge drop shaft structure based on the internal circulation airflow pipe. According to the vertical shaft structure, the problems of odor dissipation and environmental pollution of a blowdown system are solved,meanwhile, the optimal gas reduction effect can be achieved according to different water flow settings, and the requirement for pipeline overhauling and entering is not affected.

A ventilation system and method with a ventilating tube, a stylet removably disposed within the ventilating tube, and a proximal housing. A proximal housing includes a proximal end that connects to the ventilating tube, a distal end that connects to a ventilating machine, a lumen between the proximal end and distal end, an external wall between the proximal end and distal end, a filter contained within the external wall, surrounding the lumen, and connecting the proximal end and distal end, and a cavity between the filter and the external wall. A proximal housing contains at least one detection element and can be sensitive to carbon dioxide. The same proximal housing contains at least one treatment element to heat, cool, humidify, dehumidify, or provide medication to the lumen of the proximal housing.

The invention discloses a low-pressure filling method and device using electromagnetic stirring technology. The device includes a crucible furnace and a riser tube. The crucible furnace is provided with a furnace cover, so that the inside of the crucible furnace forms a sealed cavity. The top of the sealed cavity is communicated to the bottom of the cavity to be filled through a riser tube. An electromagnetic stirrer is provided beside the riser tube, and the crucible furnace has a pressurized gas inlet. Pressure is applied to metal melt in the crucible furnace to make the metal melt rise through the riser. Under the filling pressure, the metal melt enters the cavity smoothly until the entire cavity is completely filled. The temperature of the metal melt passing through the riser is 30 to60% of the liquidus temperature of the metal or alloy plus the width of its solidification temperature interval; As the metal melt flows through the riser, the metal melt is electromagnetically stirred. The device disclosed in the invention uses electromagnetic stirring to break up the generated dendrites, new crystal nuclei are added, the grain structure is refined, the pouring temperature is lowered, the mechanical properties of the casting can be improved, air intake and shrinkage of the casting can be reduced, and the casting quality and metal utilization rate can be improved.

A ventilation system and method with a ventilating tube, a stylet removably disposed within the ventilating tube, and a proximal housing. A proximal housing includes a proximal end that connects to the ventilating tube, a distal end that connects to a ventilating machine, a lumen between the proximal end and distal end, an external wall between the proximal end and distal end, a filter contained within the external wall, surrounding the lumen, and connecting the proximal end and distal end, and a cavity between the filter and the external wall. A proximal housing contains at least one detection element and can be sensitive to carbon dioxide. The same proximal housing contains at least one treatment element to heat, cool, humidify, dehumidify, or provide medication to the lumen of the proximal housing.

The invention discloses a three-section type screw rotor and a twin-screw vacuum pump comprising the same and belongs to the field of dry twin-screw vacuum pumps. The screw rotor comprises a gas suction section, a compression section and a gas exhaust section, wherein section profile lines of the gas suction section, the compression section and the gas exhaust section change continuously with a spiral expansion angle; the gas suction section and the gas exhaust section have profile lines with the equal pitch and equal sections, the pitch of the gas suction section is larger than that of the gas exhaust section, but the tooth top surface width of the gas suction section is smaller than that of the gas exhaust section; transition from the gas suction section to the gas exhaust section is realized by the aid of the compression section; the compression section has the profile line with the varying pitch and varying section; and tooth surfaces and spiral lines between the gas suction section and the compression section and between the compression section and the gas exhaust section are in smooth transition. The screw rotor can form the relatively large gas suction volume and the relatively small gas exhaust volume within a relatively small axial size, and the inner volume ratio and the sealing performance of the screw rotor are increased; thus, the screw rotor has the advantages of large inner volume ratio, good sealing performance, compact structure, small axial size and low machining difficulty, and the final vacuum and the pumping speed of the twin-screw vacuum pump are increased.

The invention relates to a pulmonary fibrosis animal model building method. The method comprises the step that a pulmonary fibrosis animal model is prepared by dripping a PM2.5 suspension into a nasalcavity. The method has the advantages that a mouse pulmonary fibrosis model is built through PM2.5 nasal cavity dripping for the first time, the feasibility is verified through experiments, and by means of PM2.5 nasal cavity dripping for eight consecutive weeks, mouse pulmonary fibrosis can be induced. According to the pulmonary fibrosis animal model building method, bleomycin is not used, an airpipe is not used for dripping, operation is easy and convenient, and the trauma is small.

The invention provides an injection supercharging cascade supercooling injection throttling transcritical CO2 system and application. The system comprises a CO2 low-temperature-level evaporator and acommon working medium-temperature-level compressor, wherein an outlet of the CO2 low-temperature-level evaporator sequentially communicates with an inlet of a secondary flow of a CO2 injector, a heating medium side of the CO2 medium-temperature-level evaporator, the CO2 compressor, a heating medium side of a CO2 gas cooler, a heating medium side of a medium-temperature-level cooling evaporator andan inlet of a heating medium side of a low-temperature-level cooling evaporator; an outlet of the heating medium side of the low-temperature-level cooling evaporator is divided into two paths to communicate with a main flow inlet of the CO2 injector and an inlet of the CO2 low-temperature-level evaporator; and an outlet of the common working medium-temperature-level compressor sequentially communicates with a heating medium side of a condenser and a main flow inlet of a common working medium injector. According to the injection supercharging cascade supercooling injection throttling transcritical CO2 system, power consumption can be reduced, irreversible throttling losses can be reduced, and the system energy efficiency can be improved.

The invention discloses a multistage compression multi-condenser intermediate complete cooling heat pump drying system which is composed of an evaporator, an air cooler, multiple stages of compressors, multiple stages of condensers, multiple stages of throttling valves and multiple stages of gas coolers. Materials are dewatered and dried according to technological requirements by arranging different numbers of stages, air is repeatedly continuously heated through multi-stage compression and multi-stage variable temperature condensation processes of working media, and irreversible loss caused by heat exchange between air and working media in the heating process can be remarkably reduced. The compression ratios of the multiple stages of compressors are small, non-azeotropic mixed working media with reasonable temperature slip can be adopted, the working media and air form good temperature matching, the heat transfer temperature difference can be further reduced, heat transfer irreversible loss of the condensers and the evaporator is reduced, and system energy efficiency is improved.

The invention provides an ejector booster two-stage super-cooling trans-critical CO2 dual-temperature system and application. The ejector booster two-stage super-cooling trans-critical CO2 dual-temperature system comprises an ejector, booster, and dual-supercooler series mechanical super-cooling cycline and a trans-critical CO2 dual-temperature-region cycle, which can mutually exchange heat; the trans-critical CO2 dual-temperature-region cycle comprises a CO2 low-temperature-stage evaporator, an outlet of the CO2 low-temperature-stage evaporator sequentially communicates with a CO2 low-pressure-stage compressor, a CO2 medium-pressure-stage compressor, a CO2 high-pressure-stage compressor, a heating medium side of a CO2 gas cooler, a heating medium side of the medium-temperature-stage cooling evaporator, a heating medium side of a low-temperature-stage cooling evaporator, a medium-temperature-stage gas-liquid separator, a low-temperature-stage gas-liquid separator and an inlet of a CO2low-temperature-stage evaporator. The ejector booster two-stage super-cooling trans-critical CO2 dual-temperature system can reduce gas exhaust pressure of the compressor, reduces a pressure ratio ofthe CO2 compressor, improves isentropic efficiency, and prolongs the service life of the compressor.

The invention provides an interstage pressure regulating structure of a two-stage screw air compressor. The structure can change the inter-stage pressure (also referred to as the exhaust pressure of afirst-stage main machine) by adjusting the air suction quantity of a second-stage main machine, thereby improving the load of a first-stage main machine rotor, thereby eliminating the noise and vibration generated by the first-stage main machine under the unloading condition. The first-stage main machine, the second-stage main machine and an oil distributing barrel are arranged along the air flowdirection, the first-stage main machine rotor and the second-stage main machine rotor are connected through a connecting structure, a second-stage main machine compression cavity and a second-stage main machine air suction cavity are in communication through a bypass flow channel, a valve plate is pressed by a return connection port of the bypass flow channel and the second-stage main machine compression cavity, and the valve plate is mounted on a mobile structure.

The invention discloses a coating for a metal mold casting of magnesium alloy thin-wall parts, wherein the coating consists of following components, by weight percent, 1.5 to 2.5% of diatomaceous earth, 2 to 3% of magnesia powder, 1.2 to 1.8% of titanium dioxide powder, 1 to 2% of zircon powder, 1.5 to 2.5% of bentonite, 2 to 4% of asbestos powder, 1.2 to 1.4% of silica sol and the balance of alcohol.

The invention discloses a filtering device based on a built-in passage board. The filtering device based on the built-in passage board comprises a shell, an exhaust pipe and a washing pipe; a separation board parallel to the horizontal plane is arranged on the sealed end of the shell; the separation board extends from the sealed end of the shell to the opening end of the shell and divides the inner space of the shell into an air filtering chamber and a sand collecting chamber; a matched sand collecting chamber cover is arranged at the end, located at the opening end of the shell, of the sand collecting chamber; the passage board vertical to the separation board is arranged on the separation board; the passage board is provided with a plurality of passages; and a sand discharging hole is formed in the separation board. The sand concentration in the air filtered by the passage board is greatly reduced, a small quantity of sand particles can not damage an air cleaner of an air compressor, and the air cleaner does not need to be frequently disassembled and washed by an operator. The sand collecting chamber has enough space to store the sand particles; after the sand particles in the sand collecting chamber are piled to a certain degree, the exhaust pipe and an air inlet of the air compressor are disconnected, the sand collecting chamber cover is opened, and the sand particles are discharged.

This invention is a ceramic grain reinforcing Al-base compound material and its preparation method, and relates to a Al-base alloy. Its components are: 2.5-15% TiN, 2.4-10%AIN, 4-6.5%Si, 0.5-1.5%Cu, 0.3-0.5%Mg, 0-0.8%Ni, 0-0.5%Ti, and the rest is Al, and the percentages are weight percentages; the preparation method adopts melt blending founding method, and the technique flow is: material matching-melting base body-adding reinforcing grains-melting-modifying treatment-pouring-heat treatment, and the size reinforcing grains is in the range of 5-10 mum, and the vacuum degree of the vacuum furnace is 1.3-1.6X10 to the power -3 Pa, the temperature is 670-800deg.C, the modifying agent is 1-18g / Kg compound material containing 1-6% Na nanometer Al alloy powder; the Al-base compound material of this invention has light weight, high modulus number, high intension, good heat-fast and wearable performances, and the preparation cost is low, the technique is simple and it can be industrially produced.

The invention discloses a sewage discharge drop shaft structure in an internal circulation air pipe, which comprises a vertical shaft and an internal circulation air pipe arranged in the shaft; the internal circulation air pipe divides the vertical shaft into a water-passing part and a water-passing air pipe part , the water passing part is connected with the water inlet pipe, the top of the inner circulation airflow pipe is lower than the bottom of the water inlet pipe, and the bottom of the inner circulation airflow pipe is higher than the top of the outlet pipe, which is used to guide the gas to form an inner airflow pipe in the airflow pipe. Circulating air flow; the internal circulating air flow pipe is vertically suspended in the vertical shaft by a fixing device, and the internal circulating air flow pipe is in contact with the inner wall of the shaft. The invention also discloses a method for using the sewage discharge drop shaft structure based on the internal circulation air flow pipe. The vertical shaft structure of the present invention improves the problem of odor emission and environmental pollution in the sewage system, and can be set according to different water flows to achieve the best gas reduction effect without affecting the requirements for pipeline maintenance and access.

The invention discloses a three-section type screw rotor and a twin-screw vacuum pump comprising the same and belongs to the field of dry twin-screw vacuum pumps. The screw rotor comprises a gas suction section, a compression section and a gas exhaust section, wherein section profile lines of the gas suction section, the compression section and the gas exhaust section change continuously with a spiral expansion angle; the gas suction section and the gas exhaust section have profile lines with the equal pitch and equal sections, the pitch of the gas suction section is larger than that of the gas exhaust section, but the tooth top surface width of the gas suction section is smaller than that of the gas exhaust section; transition from the gas suction section to the gas exhaust section is realized by the aid of the compression section; the compression section has the profile line with the varying pitch and varying section; and tooth surfaces and spiral lines between the gas suction section and the compression section and between the compression section and the gas exhaust section are in smooth transition. The screw rotor can form the relatively large gas suction volume and the relatively small gas exhaust volume within a relatively small axial size, and the inner volume ratio and the sealing performance of the screw rotor are increased; thus, the screw rotor has the advantages of large inner volume ratio, good sealing performance, compact structure, small axial size and low machining difficulty, and the final vacuum and the pumping speed of the twin-screw vacuum pump are increased.

The invention relates to the technical field of vacuum pumps, and discloses a cooling mechanism of a water ring vacuum pump. The cooling mechanism comprises a shell; an air suction port is arranged above the middle part of one side of the shell; an exhaust port is arranged below the middle part of one side of the shell; a medium is stored on the bottom surface of an inner cavity of the shell; and a driving wheel is movably connected below the middle part of the inner cavity of the shell. Through the arrangement of an internal cooling mechanism, when a beating trash removal mechanism works normally and a piston rod is rapidly thrown out under the action of centrifugal force, air to be exhausted is sucked into a refrigeration cavity through a vent hole, and the air suction amount in the refrigeration cavity is small under the effect that the opening range is small when the vent hole sucks air; and under the effect that the outward moving amplitude of the piston rod is large, air in the refrigeration cavity expands under the effect of negative pressure and absorbs a small amount of heat, so that when the water ring vacuum pump works normally, the refrigeration cavity continuously absorbs a small amount of heat, and the inner cavity of the water ring vacuum pump is continuously subjected to heat absorption and cooling.

The invention relates to a vehicle hub using high impact toughness Al-Si-Mg alloy new material and the manufacture method. It uses Al, industrial pure Si, Al-Mg alloy, Al- Cu alloy, Al-Sr alloy, Al-rare earth intermediate alloy, and Ti power as raw material and taking smelting, ultrasonic, electromagnetic wave to whisking equally, degassing by nitrogen, filtering by double stage multi hole ceramic, and casting by water cooling crystallizer. The invention could improve impact toughness, and improve the casting capability.

The invention discloses a degassing and deodorizing method for acetylene apparatus carbon black water. The degassing and deodorizing method comprises that (1) to-be-treated carbon black water is pressurized, the pressured carbon black water enters a gas stripping tower, and is sprayed on the middle-upper portion of the gas stripping tower, and gas stripping gas enters the tower from the middle-lower portion of the gas stripping tower, and is concentrated tail gas from a concentration section; (2) carbon black water recycled by an acetylene apparatus enters the water spraying section on the topportion of the gas stripping tower, the stripped gas stripping gas is subjected to spray cooling with the carbon black water, and the cooled gas stripping gas enters the middle-lower portion of a vacuum pump sucking tank from the top portion of the gas stripping tower; (3) the carbon black water is sprayed downward from the upper portion of the vacuum pump sucking tank, the stripped gas strippinggas discharged from the top portion of the gas stripping tower is further cooled in the tank, and the gas stripping gas discharged from the tank top is conveyed to a cracking gas total pipe by a vacuum pump; and (4) the carbon black water discharged from the bottom portion of the vacuum pump sucking tank is introduced into the tower kettle of the gas stripping tower, the discharged carbon black water and the carbon black water degassed at the tower kettle are pressurized, and the pressurized carbon black water is conveyed into a subsequent carbon black water groove so as to be further treated. According to the present invention, with the method, the acetylene apparatus carbon black water degassing effect can be improved, and the environmental protection problem can be solved.

The invention discloses a pre-separation system for a positive-displacement air compressor. The pre-separation system for the positive-displacement air compressor comprises a shell. An exhaust pipe close to the closed end is installed at the top of the shell. A partition plate which is parallel to the horizontal plane is arranged at the closed end of the shell. The partition plate extends from the closed end of the shell to the open end of the shell and divides the internal space of the shell into an air filtering chamber and a sand collecting chamber. A sand collecting chamber cover matched with the sand collecting chamber is arranged at the end, located at the open end of the shell, of the sand collecting chamber. Channel plates perpendicular to the partition plate are arranged on the partition plate. A plurality of channels are formed in each channel plate. Sand discharging holes are formed in the partition plate. The sand content of air filtered by the channel plates is greatly reduced, and an air filter of the air compressor is prevented from being damaged by a small amount of sand, and an operator does not need to dismount and clean the air filter frequently; and the space of the sand collecting chamber is large enough to contain sand, the air exhaust pipe is disconnected with an air inlet of the air compressor after the sand in the sand collecting chamber is accumulated to a certain degree, the sand collecting chamber cover is opened, and then the sand is discharged.

Provided is a vehicle power transmission system which quickly performs shift operations in the transmission and is capable of alleviating the operator's discomfort due to so-called torque loss during said shift operations. This vehicle power transmission system (100) is provided with an engine (110) the operation of which is controlled by an ECU (300), a clutch (210) and a transmission (240). The engine (110) is provided with a bypass pathway (121) in a state in which a throttle valve (117) is bypassed by an intake pipe (116) which introduces a fuel-air mixture into a cylinder (111). An idle regulating valve (122) is provided in the bypass pathway (121). The idle regulating valve (122) regulates the amount of air that bypasses the throttle valve (117) and is supplied to the cylinder (111). The ECU (300) reduces the deceleration torque in the transmission (240) by opening the idle regulating valve (122) prior to shift change operations of the transmission (240).

The invention discloses a coating for a metal mold casting of magnesium alloy thin-wall parts, wherein the coating consists of following components, by weight percent, 1.5 to 2.5% of diatomaceous earth, 2 to 3% of magnesia powder, 1.2 to 1.8% of titanium dioxide powder, 1 to 2% of zircon powder, 1.5 to 2.5% of bentonite, 2 to 4% of asbestos powder, 1.2 to 1.4% of silica sol and the balance of alcohol.

The invention discloses a cylinder assembly, comprising a cylinder body, the cylinder body has an air suction channel, the inner wall of the air suction channel has a valve chamber, and a valve is reciprocally arranged in the valve chamber, so The movement direction of the valve is perpendicular to the axial direction of the suction channel, and a driving device that can drive the valve to extend into the suction channel is arranged in the valve chamber. The cylinder assembly can effectively reduce the operating load of the compressor when the discharge pressure is high and the suction and discharge pressure difference is large. The invention also discloses a compressor using the cylinder assembly.

The invention discloses a pre-sand-discharging structure for a rotor-type air compressor. The pre-sand-discharging structure comprises a shell, an air exhaust pipe, a rinsing pipe, a first grating, a second grating and a third grating, wherein a separation plate is arranged on the closed end of the shell; the separation plate extends to an open end from the closed end of the shell, and divides the space in the shell into an air filter chamber and a sand collection chamber; the end, located at the open end of the shell, of the sand collection chamber is provided with a sand collection chamber cover matched with the end; a passage plate vertical to the separation plate is arranged above the separation plate; a plurality of passages are arranged on the passage plate; and a sand discharging hole is formed in the separation plate. The sand content in air filtered by the passage plate is greatly lowered; the air filter of the air compressor cannot be damaged by a small amount of sand; operation personnel do not need to disassemble and clean the air filter frequently; the sand collection chamber has enough space to contain sand; and when sand in the sand collection chamber accumulates to a certain degree, the air exhaust pipe is disconnected from the air inlet of the air compressor, and the sand chamber cover is opened, so that the sand can be discharged.