39results about How to "High efficiency filterability" patented technology

The invention relates to the technical field of manufacturing of fiber composite membranes, particularly a preparation method of a multilayer-structure nano fiber composite membrane for filtering particulates in air. The preparation method comprises the following steps: (1) sequentially spinning a first nano fiber membrane layer to nth nano fiber membrane layer onto a matrix by electrostatic spinning, wherein n is a whole number ranging from 1 to 50; (2) covering a nano fiber membrane protective layer on the upper surface of the nth nano fiber membrane layer and the exposed surfaces of all the nano fiber membrane layers to obtain a semifinished product; and (3) compounding the semifinished product to obtain the product. The method can enhance the uniformity and mechanical properties of the filter membrane, and can also enhance the barrier efficiency of the filter membrane for particulates and relatively lower the air drag.

The invention discloses a method for preparing a quaternary ammonium salt chitosan and polyvinyl alcohol antibacterial filter composite material. The method is characterized by comprising the following steps: mixing and stirring chitosan powder, acetic acid and deionized water to form a chitosan acetic acid solution; adding isopropyl alcohol, stirring and standing; heating a container through a water bath, and dropwise adding a certain amount of 2,3-epoxypropyltrimethylammonium chloride at set intervals to react; at the end of the reaction, adding absolute ethanol to the container, precipitating, performing suction filtration, and then soaking with acetone, washing, performing suction filtration, and drying to obtain modified quaternary ammonium salt chitosan; preparing a spinning solutionfrom the modified quaternary ammonium salt chitosan, and adding the spinning solution into a polyvinyl alcohol spinning solution to be mixed and stirred to obtain a mixed spinning solution, and obtaining the composite material by an electro-spinning method. The method disclosed by the invention satisfies the development requirements that the material is light and thin, and has good filterabilityand excellent antibacterial performance and the like in practical application, and can be used for preparing biomedical antibacterial protective materials such as biofiltration membranes, protective masks, wound dressings and the like.

The invention discloses an isolation compartment device with negative pressure ventilation and epidemic prevention medical functions. The device comprises an isolation compartment, individual partitions, a stretcher door, an isolation door, a stretcher fixing position, a sterilizing lamp, a toilet, a negative pressure ventilation and disinfection system and a main valve, wherein the isolation doorand the stretcher door are respectively mounted at one side of the isolation compartment, the individual partitions, the stretcher fixing position, the sterilizing lamp and the toilet are mounted inthe isolation compartment, and a valve, a pump, a generator and the main assembly of the negative pressure ventilation and disinfection system are mounted in an equipment compartment. In addition, anoxygen delivery pipeline, a disinfectant pipeline and an exhaust pipeline which are connected with the negative pressure ventilation and disinfection system are respectively mounted in the isolation compartment, and the main valve is mounted on the oxygen delivery pipeline, the disinfectant pipeline and the exhaust pipeline. The isolation compartment device with negative pressure ventilation and epidemic prevention medical functions, disclosed by the invention, is good in air tightness and reasonable in arrangement and has the properties of high efficiency, multiple filtration and efficient filtration; and the equipment is independently partitioned to ensure that the inside of the compartment is easy to sterilize, disinfect and clean, the exhausted gas is not polluted, and a vehicle is clean when the vehicle is used every time.

The invention belongs to the civilian air purification processing field and especially relates to a multifunctional air purifier adopting the combination of a negative ion generator, an active-carbon mesh and a photocatalyst so as to effectively eliminate contamination generated in decoration process while sending out a great amount of negative ions. An air inlet and an air outlet are respectively arranged on the casing of the multifunctional air purifier; the negative ion generator, a fan and strainers are arranged in the casing; and the strainers are arranged between the air inlet and the fan. The multifunctional air purifier is characterized by arranging the active-carbon mesh and a photocatalyst mesh between the strainers and the fan and arranging an ultraviolet lamp around the photocatalyst mesh. The strainers can be classified into a primary-effect strainer, an intermediate-effect strainer and a high-effect strainer, wherein the high-effect strainer is arranged on the back of the active-carbon mesh. The ultraviolet lamp arranged around the photocatalyst mesh is provided with ultraviolet wavelength between 40 nm and 387.5 nm. The purpose of the invention is to overcome problems of the prior art that the single air treatment manner is adopted, the contamination in air cannot be reduced effectively and the like.

The invention discloses a high-efficiency dust collection device for coal mining. The high-efficiency dust collection device for coal mining comprises a shell body, and dedusting water is stored in the shell body. A fixed bracket is arranged at the bottom of the shell body, and the shell body is fixed on the fixed bracket. An air suction dryer is arranged at the top of the shell body, and a wind suction hood is arranged at the front end of the air suction dryer and a draught fan is arranged in the air suction dryer. The after end of the air suction dryer is communicated with the bottom of theshell body by a conduit pipe. A gas density sensor is arranged in the top end of the shell body and a wind pipe is arranged at the front side of the inner of the shell body top. By the high-efficiencydust collection device for coal mining, the structure is ingenious and reasonably arranged, specifically that firstly, the coal dust in the raise dust is wiped off effectively and the air in work place is cleaned; secondarily, the gas density in work place can be tested and reduced, and the security is improved; thirdly, efficient filtration and sedimentation of coal dust is achieved and the coaldust is convenient to discharge; fourthly, an actuating mechanism in an engine room is ingeniously arranged and the structure is compact and simple.

The invention belongs to the field of novel materials and photocatalysis and particularly relates to a preparation method and application of a dark light catalytic non-photo-catalyst / activated carbon fiber composite material. The dark light catalytic non-photo-catalyst / activated carbon fiber composite material is characterized by comprising a non-photo-catalyst, an activated carbon fiber raw material, an adhesive and water. The preparation method comprises the following steps: cutting the activated carbon fiber to required size and perforating; weighing the non-photo-catalyst, and adding water to form a non-photo-catalyst solution; preparing a chitin powder adhesive; spray coating the non-photo-catalyst solution onto the surface of the activated carbon fiber, drying, spray coating the adhesive onto the surface of the coated non-photo-catalyst solution to fix the adhesive on the surface of the activated carbon fiber, and drying. The dark light catalytic non-photo-catalyst / activated carbon fiber composite material can purify pollutants through adsorption and catalysis functions under dark light or sufficient light, the formaldehyde degradation efficiency within 1 hour reaches 99.9%, the load is firm, the specific surface area is high, and the composite material can be regenerated in situ under sunlight exposure or at low temperature of 60 DEG C.

The invention discloses a real-time data loading method based on a data flow technology. The method comprises the steps that a data flow operator set is set; a plurality of operators are selected from the operator set according to service demands to generate a real-time query processing expression of data flow; the real-time loading network of the data flow is set according to the real-time query processing expression; the data flow entering in the real-time loading network is driven and controlled, and buffer memory space is dynamically distributed for the data flow; result data flow is output and is loaded to a real-time data warehouse. The invention further discloses a real-time data loading device based on the data flow technology. The method and device are used for achieving real-time conversion and continuous loading of data, and the real-time loading network can be established in real time.

The invention aims at providing a solution melt co-spinning electrospinning device for preparing composite fibers. The device comprises a first sleeve, a second sleeve, a third sleeve and a fourth sleeve which are nested with one another in sequence, straight flow channels and annular flow channels are formed among the sleeves and used for flow of gas and melts, a needle head is fixed to the lowerend of a central pipe from the interior of the fourth sleeve, the top of the central pipe is connected to an injection pump through an insulated guide pipe and connected to a high-voltage electrostatic generator, and jetting of a solution is formed at the tip of the needle head; a high-voltage electric field is formed between the annular tip of the first sleeve and the needle head, the annular tip is inductively charged, the melts are self-organized to form a uniformly distributed multi-jet, and the annular airflow prevents solution-spun fibers from flying to the annular tip; moreover, the two fibers are stretched to reduce the fiber diameter, and the fibers formed by the melts and the solution are entangled and adhered to each other during jetting to form the composite fibers. The devicehas the advantage that composite fiber membranes with high porosity, a high specific surface area and high strength can be prepared.

The invention discloses a biofilter for organic waste gas. The invention relates to the technical field of waste gas treatment devices. The tower comprises a tower body, wherein the tower body is sequentially provided with a water storage layer and a biodegradation layer from bottom to top; wherein an exhaust port is formed in the top of the tower body, a gas distribution device is arranged in thewater storage layer, a gas inlet of the gas distribution device is connected with a fan, a spraying assembly is arranged in the tower body, the spraying assembly is located above the biodegradation layer, and the spraying assembly is connected with the water storage layer through a first liquid inlet pipeline provided with a circulating water pump. The technical problem that in the prior art, theorganic waste gas filtering efficiency is poor is solved. A three-stage waste gas filtering stage is adopted, the filtering efficiency and effect of organic waste gas are greatly improved, meanwhile,the manufacturing cost is reduced, the economic benefits are improved, and the device further has the functions of maintaining the efficient filtering performance of the biodegradation layer, periodically cleaning the biodegradation layer, controlling the water content and the like.

The invention discloses a thermal comfort PM2.5-proof nanofiber mask filter element and a preparation method thereof. The filter element is composed of an infrared light transmitting layer 5 for enhancing radiation heat dissipation of a human body and a visible light blocking layer 6 for preventing atmospheric environment from radiating heat to the face of the human body. The two layers of functional nano-films are intensively sewed to form the mask filter element, so that PM2.5 is prevented from invading a human body, and meanwhile, the face of the human body is cooled. The average fiber diameter of the prepared thermal comfort nanofiber filter element membrane is 0.2-1 micron, the porosity of the membrane is larger than or equal to 85%, the moisture permeability is 0.01-0.02 g / (cm < 2 >h), the filtering efficiency of particles larger than or equal to 0.3 micron is 90%-99.95%, and the resistance is 3-200 Pa. The infrared transmittance of the prepared thermal comfort mask filter element to a human body is larger than or equal to 85%, and the transmittance of visible light carrying a large amount of radiant heat in the environment is smaller than or equal to 60%.

The invention relates to an intelligent fruit and vegetable cleaning device based on the Internet of Things, which comprises a cleaning chamber, a neutralizing chamber and a filtering chamber. Fruitsand vegetables to be cleaned are put into a cleaning tank, firstly the fruits and vegetables immersed in a water body is subjected to bubble cleaning through a bottom air jet disc to remove pesticideresidues on the surfaces of the fruits and vegetables, then a bottom plate is clamped to the bottom of the cleaning tank through a bottom plate extending part, and then the rotation of a driving motoris used to drive the cleaning tank to rotate in the water body, so that the deep cleaning of the fruits and vegetables is achieved; and after the cleaning is finished, the cleaning tank is lifted upwards through a lifting component, so that the cleaning is finished. Through the steps of filtering, neutralizing, adsorbing and the like in the water body in the cleaning process, the repeated reuse of the cleaning water is achieved.

The invention relates to a nano germanium-containing filter element, which comprises a nano-germanium filtering layer and an inner non-woven protective layer; and a cavity through which water can passis formed at the inner side of the filter element. A drinking water purification treatment material adopted by the nano germanium-containing filter element comprises the following components in percentage by weight: 0.2 to 3 percent of nanometer germanium, 5 to 20 percent of tourmaline nano-powder, 1 to 10 percent of nano-silver antimicrobial material, 5 to 20 percent of hot-melt powder and the balance of active carbon. According to the nano germanium-containing filter element, drinking water contains trace element germanium and has high activity, and can effectively absorb and filter iron rust, suspended substances, silt, peculiar smell, algae, flocculation chemicals, harmful conglutination substances and heavy metal in tap water; when antibiosis and disinfection are carried out, water processed by germanium filtering simultaneously has the function of regulating the abnormal electric potential and magnetic field of a human body, can capture the electronic magnetic field of cancer cells so as to reduce the electric potential of the cancer cells and inhibit the deterioration of the state of illness of cancer, and is suitable for crowds lacking the germanium, middle and old aged groups and cancer and tumour patients of wide areas lacking the germanium.

The invention relates to a high-efficiency mineral water purifying device which comprises a stirring ejector, a settling basin, a solid-liquid separation basin and a three-stage filter tank. By arranging the stirring ejector, through the combination of the settling basin of the specific structure, primary separation efficiency is improved; by arranging an inclined large-aperture filter plate on the solid-liquid separation basin, solid-liquid separation efficiency is improved; by arranging the multi-stage filter tank, filter water is subjected to settling again during filtering and then filtered, and the high-efficiency filtering effect is achieved on the aspect of physics.

The invention discloses a diatomite filter, which comprises a stirring kettle, a diatomite storage tank, a bracket, a filter barrel, a filter plate, a first circulating pump, a second circulating pumpand a recovery tank, wherein the left side of the upper end of the stirring kettle is connected and provided with a water inlet pipe; the right side of the upper end of the stirring kettle is connected and provided with the diatomite storage tank; the middle part of the upper end of the stirring kettle is connected and provided with a motor; the output end of the motor is connected and provided with a stirring shaft; a stirring fan blade and a stirring magnetic brush are symmetrically arranged at the periphery of the stirring shaft; the filter barrel is connected and arranged at the lower endof a flange; the filter plate is connected and arranged in the filter barrel through a strip-shaped notch; fixing bolts penetrate through and arranged at both ends of the filter barrel and the flange; a tee joint is connected and arranged at the lower end of the filter barrel; the first circulating pump is connected and arranged at the right end of the tee joint; and the second circulating pump is connected and arranged at the left end of the tee joint. According to the diatomite filter provided by the invention, the filter barrel which is movably connected is adopted, so that the filter plate is convenient to replace and clean; and the tee joint is used for connecting a pump set, so that the operation is convenient.

The invention discloses a small and medium-sized river channel floating oil filtering, intercepting and cleaning device based on a dam body. The device can effectively intercept pollutants such as oilstains and floating garbage on the water surfaces of small and medium-sized rivers and sundries flowing along with water in a water body, and can collect and clean the automatically salvaged pollutants on a dry sewage cleaning platform, floating oil on the surface of the water body can be adsorbed and filtered, a floating oil absorption device can go deep into the river channel to absorb oil stains in the river channel water body, meanwhile, a secondary automatic intercepting and filtering platform is arranged at the lower part of a drain opening to perform secondary efficient filtering, intercepting and cleaning on the water body, water body treatment can be performed scientifically and efficiently, and therefore, the small and medium-sized river channel floating oil filtering, intercepting and cleaning device based on the dam body has important practical significance in small and medium-sized river water body treatment, and is high in system integration level, compact in structure,convenient to process, high in practicability and suitable for wide popularization.

An environment-friendly high-rise building public flue structure and a flue cleaning system comprise a flue vertical shaft (1). The environment-friendly high-rise building public flue structure and a flue cleaning system are characterized in that vertical sliding rails (13) are fixedly arranged on the inner side wall of the flue vertical shaft (1), movable beams are installed on the outer sides of the four faces of the lower end of a machine frame (14) respectively, a telescopic adjusting mechanism is installed between every two opposite movable beams, one or more rotary cleaning cylinders (19) are horizontally arranged on a cleaning cylinder mounting seat (18), an elastic scraping plate (32) corresponding to the side wall of the flue vertical shaft (1) is arranged at the lower end of each movable beam, and a sewage collecting cover (33) with certain elasticity is arranged on the movable beams and the machine frame (14). The structure is reasonable, the structure and the system can enter a flue to perform automatic cleaning, cleaning sewage can be collected, a very good descaling and cleaning effect is achieved, lampblack and dirt are prevented from blocking a smoke exhaust channel, and meanwhile the fireproof safety performance is improved.

The invention discloses a preparation method of a polydimethylsiloxane (PDMS) composite sponge capable of continuously and efficiently filtering PM, which comprises the following steps: preparing a PDMS sponge by a sacrificial template method, then putting the PDMS sponge into a dopamine hydrochloride solution, and preparing a PDA-coated PDMS composite sponge by auto-polymerization; and soaking the obtained PDA (at) PDMS composite sponge in a mixed solution of 2-methylimidazole and zinc nitrate hexahydrate, so as to prepare the ZIF-8 (at) PDA (at) PDMS composite sponge. The preparation process is simple, the cost is low, the obtained ZIF-8 (at) PDA (at) PDMS composite sponge still has extremely high filtering performance under severe environments such as high temperature and high humidity due to the thermal stability and hydrophobicity, the shape is controllable, the mechanical performance is excellent, and the application range is greatly widened.

The invention discloses a multifunctional fresh air purifier. The purifier comprises boxes and a humidification bin arranged at the top of the boxes, a wind guide cover is arranged on the humidification bin, and an indoor fresh air outlet is formed in the wind guide cover; the purifier further comprises an air inlet bin, a plurality of dehumidification, heat and refrigeration bins, a fresh air binand a filter bin which are sequentially arranged in the boxes from bottom to top; an indoor compensation air inlet, a primary-efficiency filter and a medium-efficiency filter are sequentially arranged in the air inlet bin from bottom to top; condensers and evaporators are arranged in the dehumidification, heat and refrigeration bins; a fresh air fan and a controller are arranged in the fresh airbin; a power driver and a high-efficiency filter are arranged in the filter bin; a humidifier is arranged in the humidification bin; and a photocatalytic sterilization and disinfection device is arranged between the high-efficiency filter and the humidifier. According to the purifier, two, three or more dehumidification, heat and refrigeration bins can be selected to be used according to the requirements of a field for dehumidification, heat and refrigeration.

The invention discloses a fuel filter, and relates to the technical field of vehicle fuel filter systems, the fuel filter comprises a main shell and a filter cartridge, the main shell is provided with an oil inlet and an oil outlet; the filter cartridge is internally provided with a filter assembly, and the filter assembly comprises a first filter assembly and a second filter assembly; a first cavity is formed between the first filtering assembly and the inner wall of the main shell, the first cavity communicates with the fuel inlet, and the first filtering assembly can filter particulate matter in fuel oil; a water outlet is further formed in the main shell, a second cavity is formed between the first filtering assembly and the second filtering assembly, the second cavity communicates with the water outlet, and the second filtering assembly can filter water in fuel oil; a third cavity is formed in the inner side of the second filtering assembly and communicates with the oil outlet. According to the invention, the effects of impurity filtration and oil-water separation can be realized, and the problem of corrosion of components in a fuel system in the use process of a vehicle is effectively solved.

The invention discloses an ecological retention gap applied to municipal engineering and a mounting method. The ecological retention gap comprises a retention gap main body, a rainwater ecological filtering treatment mechanism and an anti-waterlogging efficient drainage mechanism. The rainwater ecological filtering treatment mechanism is composed of a top precipitating and filtering intercepting net, a supporting rod of the intercepting net, a plant purification layer, a water guide filter screen and a purified water drainage pipe at the bottom end of the plant purification layer. The anti-waterlogging efficient drainage mechanism is composed of a flood discharge drainage pump in the middle part inside, water inlets in two sides, a bottom water storage circulating pipeline, a left distributary pipe and a right distributary pipe. When the ecological retention gap is paved and mounted, a rapid paving device is connected to another plate paving and splicing part, a splicing protruding bayonet pin on the top of the paving and splicing part is embedded into a splicing groove in the bottom of the paving device and is to pop up to be locked in a pop-up part clamping groove to be fixed after being embedded into a hollow groove in the pop-up part clamping groove, so that the ecological retention gap is suitable for being used in the technical field of municipal engineering and has a wide development prospect in the future.

The invention relates to the field of machine tools, in particular to an efficient cooling method for a turning and milling composite machine tool. Through the efficient cooling method and introduction of a residue treatment box in the method, a filter barrel in the residue treatment box can be rotationally switched, residues filtered on the surface of the filter barrel can be automatically scraped off, the efficient filtering performance of the filter barrel is guaranteed, nozzles can sufficiently and constantly spray out clean cooling liquid, and it is guaranteed that the turning and milling composite machine tool is efficiently cooled; and the residue treatment box used in the efficient cooling method achieves automatic cleaning of the filter barrel, the clean surface of the filter barrel will participate in filter work, meanwhile, the cleaned filter surface is rotated to the bottom position, and residues on the surface can be completely removed through back flushing of the cooling liquid, so that subsequent use is convenient.

The invention relates to a purification device for coal mine water. The purification device comprises a stirring ejector, a sedimentation tank, a solid-liquid separation tank and a filter box. By arranging the stirring ejector in combination with the sedimentation tank of a specific structure, the primary separation efficiency is improved; by improving the material of stirring blades, the service life of a stirrer is substantially prolonged; by arranging an inclined large-aperture filter plate on the solid-liquid separation tank, the solid-liquid separation efficiency is improved; by improving a multi-layer filter plate of the filter box, water obtained finally meets the qualified water quality standard. By the low-cost physical arrangement, coal mine water is efficiently purified.

The invention discloses an aluminum electrolysis fume purification method and a dust remover. According to the method, adsorbents of fresh aluminum oxide and fluorine-containing aluminum oxide are added into a purification system by means of main flue inlets and auxiliary flue inlets independently formed in all dust remover units; most electrolysis fume containing high-concentration hazard substances is subjected to primary purification after a large amount of fluorine-containing aluminum oxide is added into the system from the main flue inlets, and the fume subjected to primary purification is further purified through the fresh aluminum oxide added from the auxiliary flue inlets, so that fractional purification of the electrolysis fume is achieved. The method and the dust remover have the advantages that the purification effect is good, and the working efficiency of the dust remover is high. When two dust removers are arranged in a mirror mode, wall plates of boxes in the dust remover units can be used as main gas outlet pipes, and the system manufacturing cost can be lowered.

The invention relates to a composite electret fiber filter material, which is prepared by the following method: (1) compounding a polytetrafluoroethylene film and a base film material to obtain a composite material; (2) injecting the composite material into an electrode to obtain Composite electret film; (3) The composite electret film is stretched into fibers and formed into a net to obtain the product. The composite electret filter material of the invention has high electret charge stability, excellent filtration efficiency, low pressure loss, long service life, wide application and wide adaptability.

The invention belongs to the field of fiber composite membrane preparation methods, and discloses a preparation method for in-situ growth of nanoscale (less than 100 nm) ZIF-8 crystals on the surfaces of inert polypropylene melt-blown cloth fibers. The preparation method comprises the following steps of firstly, modifying polypropylene fibers with polyacrylamide to enable the polypropylene fibers to have active groups, then adjusting the proportion of metals and organic ligands of ZIF-8 so as to control the size of the crystals, and uniformly growing the nanoscale ZIF-8 crystals on the surfaces of the polypropylene fibers through an in-situ growth method. As the nanoscale ZIF-8 crystals have larger specific surface area, higher porosity and abundant active functional groups, gas circulation and particulate matter capture can be facilitated. The ultra-small ZIF-8 particles are firmly combined on the surfaces of the fibers, and original holes among the fibers cannot be blocked; while the filtration efficiency is relatively high, the increase of filtration resistance can be greatly inhibited, and the Trade-off effect of a fiber filtration membrane is effectively reduced; and the method is mild in reaction condition, simple in preparation process and suitable for amplification synthesis and actual production application.

The invention discloses a SiO-based 2 @PDA-Ag composite antibacterial finishing nonwoven fabric, the preparation method of the nonwoven fabric comprises the following steps: (1) preparation of porous nano-silica by sol-gel method; (2) preparation of surface-attached polydopamine membrane modification material, i.e. SiO 2 @PDA; (3) Preparation of silver-loaded modified silica with core-shell structure, namely SiO, by in situ reduction method 2 @PDA‑Ag; (4) Preparation of nonwovens with composite antibacterial finishing by impregnation method. The reaction raw materials of the present invention are efficiently utilized and the reaction condition is room temperature, which has the characteristics of environmental protection, energy saving, and no pollution. Meanwhile, the nonwoven fabric of the present invention has the advantages of strong sterilization ability, no toxic side effects, and high air permeability.

The invention discloses a biological filter tower for organic waste gas, which relates to the technical field of waste gas treatment devices, and comprises a tower body. There is a built-in air distribution device in the water layer, and the air inlet of the air distribution device is connected to a fan. There is a spray assembly in the tower body. The spray assembly is located above the biodegradation layer. The pipes connect the aquifers. The invention solves the technical problem of poor organic waste gas filtration efficiency in the prior art. The invention adopts a three-stage waste gas filtration stage, which greatly improves the filtration efficiency and effect of organic waste gas. At the same time, the invention reduces manufacturing costs and improves economic benefits Moreover, the present invention also has the functions of maintaining the high-efficiency filtration performance of the biodegradable layer, regularly cleaning the biodegradable layer, and controlling water content.

The invention discloses a low-resistance and high-efficiency combined type fresh air filtering system. The low-resistance and high-efficiency combined type fresh air filtering system comprises a freshair filtering box body (1), an air inlet pipe (2), an air inlet guide vane (3), a plate filter (4), a bag filter (5), a pleated filter (6) and an air outlet pipe (7) which are connected in sequence,outdoor polluted fresh air enters the filtering box body (1) through the air inlet pipe (2), is filtered by the plate filter (4), the bag filter (5) and the pleated filter (6) in a combined mode, andthen is sent into indoor space from the air outlet pipe (7). According to the low-resistance and high-efficiency combined type fresh air filtering system, through the combined filtering mode of the plate filter, the bag filter and the pleated filter, the dust content is mainly distributed in the plate filter and the bag filter with larger dust content and lower resistance, and the pleated filter ensures the high-efficiency filtering performance of the whole filtering system so as to realize the high-efficiency filtering performance with ultra-low resistance, and huge energy saving effect is brought in the operational process.