36results about How to "Realize hierarchical filtering" patented technology

The invention relates to the field of cereal drying, and in particular relates to a cereal drying machine. The cereal drying machine comprises a drying tower (1) and a heat pump (2) which is communicated with the drying tower (1) and is used for providing hot air for the drying tower, wherein the heat pump (2) comprises a pump shell (3) and an evaporator (4) arranged in the pump shell; the cereal drying machine is characterized by further comprising a dust collection room (5) which is communicated with the drying tower (1) and is used for collecting waste air discharged by the drying tower; and a defrosting heating device is arranged on the evaporator (4). The cereal drying machine can efficiently filter the discharged waste air, and the phenomenon that cold air is generated at an air outlet where the evaporator is positioned during defrosting of the evaporator is avoided.

The invention discloses an environmental-friendly dust collecting room for a grain drier, which comprises a box body (1), wherein a filter screen group used for dividing an inner cavity of the box body (1) into an upper chamber (1.1) and a lower chamber (1.2) is set inside the box body (1); the lower chamber (1.2) is provided with an inlet (1.3); the upper chamber (1.1) is provided with an outlet (1.4) used for the discharged waste gas inside the lower chamber after the waste gas passes through the filter screen group; and the environmental-friendly dust collecting room for the grain drier is characterized in that the filter screen group comprises an initially filtering filter screen and a top-layer filter mechanism (5) set above the initially filtering filter screen. The invention provides an environmental-friendly dust collecting room for a grain drier that is capable of filtering waste gas discharged from the grain drier with high efficiency to eliminate dust particles and impurities in the waste gas.

The invention relates to a vector tile data processing method, a vector tile data processing device, vector tile data processing equipment and a storage medium. Calculating a space range of the request tile according to the tile request parameter; determining a target layer according to a layer display level filtering rule; calculating a target filtering rule according to the tile request parameter and the target distribution density of the target layer in the space range; and filtering the to-be-requested tile data according to a target filtering rule to determine target tile data, the front-end device generating a vector tile according to the target tile data. And the tile generation efficiency and the vector tile service performance are improved.

The invention discloses a graded sewage treater for environmental protection engineering, which comprises a box body. A cleaning mechanism is installed in the upper portion of the box body, a handle is fixedly connected to the left end of a cross rod, and the outer wall of the left side of the cross rod is attached to the inner wall of the middle of a rubber pad. According to the graded sewage treater for environmental protection engineering, the cross rod drives two hair balls on a rotating block to move left and right in a first filter plate, so that the first filter plate can be dredged, the first filter plate cannot be blocked, and the problem that the filtering equipment on the existing sewage treater for environmental protection engineering is blocked due to long-term use and normaloperation of the equipment is affected is solved. A rubber ring on a clamping block leaves a second filter plate, and at the moment, the second filter plate can be rapidly disassembled for maintenanceor replacement, so that the problem that most of existing sewage treatment devices for environmental protection engineering are mounted by bolts or the like and are inconvenient to disassemble for maintenance or replacement is solved.

The invention relates to an automatic pressure flush type rapid filter which comprises a bucket, characterized in that a clear water discharge pipeline is arranged at the upper end of the bucket, a pre-filtering water pipeline and a sludge discharge pipeline are respectively arranged at the lower end of the bucket, a filtering material layer is arranged in the bucket and comprises a plurality of filtering material elementary layers arranged sequentially from the top down, and the filtering material elementary layers can be sequentially reduced in hole diameter from the bottom up according to particle diameters. In a flushing state, muddy water is filtered by layers from the bottom up through a water inlet pipeline and the filtering material layer, filtered clear water is discharged from the clear water discharge pipeline at the upper end, and sludge deposits in a sludge bucket and is discharged from the sludge discharge pipeline; and in a back flushing state, water reversely flows downwards from a clear water storage area to flush the filtering material layer by the self gravitational potential energy, and accumulated sludge is discharged from the sludge discharge pipeline below. The process is combined with a rapid filtration self-solidifying process, back washing is performed by the self pressure of the liquid level of the water, and a back washing pump is saved, thus saving the cost and having good effects.

The invention discloses a segmented treatment vertical sewage treatment device. The vertical sewage treatment device comprises a vertical type treatment tower, wherein a plurality of horizontal partition plates are sequentially arranged in the treatment tower from bottom to top at intervals and the inner cavity of the tower is divided into a plurality of processing chambers; the adjacent processing chambers are connected through a communicating pipeline to form a serpentine walking path, a water inlet is formed in the processing chamber at the bottommost side, and a water outlet is formed in the processing chamber at the uppermost side; a bypass pipeline is further connected to a bypass pipeline, and a bypass switch valve is arranged on the communicating pipeline and the downstream of theconnecting portion of the bypass pipeline, and each processing chamber is provided with a sewage filtering device, when sewage treatment is carried out, sewage is fed from the water inlet and is discharged from the water outlet; when the sediment is cleaned, clean water is cleaned from the water outlet and is discharged from the water outlet. The device has the advantages that the occupied area issmall, the centralized degree is high, the sewage can be treated in a segmented mode, and the self-cleaning function is achieved.

The invention relates to the technical field of purifying, in particular to an inlet gas filter device and a boiler provided with same. The inlet gas filter device provided by the invention is arranged at an air inlet of a first object, and comprises a filter mechanism and a water curtain forming mechanism, wherein the filter mechanism is provided with a gas inlet, a gas outlet, and at least a primary filter screen arranged between the gas inlet and the gas outlet; the gas outlet communicates with the gas inlet; and the water curtain forming mechanism is used for forming a water curtain on each stage of the filter screen. According to the inlet gas filter device provided by the invention, the water curtain is formed on each stage of the filter screen through the water curtain forming mechanism, so that the water curtain on the filter screen is in sufficient contact with inlet air of a first object, adhesion and filtration on dust in inlet air is realized by utilizing the adhesion of water; circulating water continuously flushes the filter screen, so that the filter screen is kept transparent, and therefore, the filter screen is prevented from being blocked as a result of too much dust; and the device does not need to dismount for maintaining, and circulating water only needs to change, so that maintenance is relatively simple, and maintenance cost is relatively low.

The invention discloses a collecting device suitable for marine plankton. The collecting device comprises a collecting mechanism, a floating body arranged above the collecting mechanism, a sinking mechanism arranged below the collecting mechanism and a controller, wherein the collecting mechanism comprises a collecting box and a filtering component arranged in the collecting box, an opening and closing component is arranged at the upper end of the collecting box, and the sinking mechanism comprises a fixing balancing weight arranged at the lower end of the collecting box, a releasing component arranged below the fixing balancing weight and a sinking balancing weight with a hanging rope. The collecting device is simple in structure and convenient to use, the floating body above the collecting mechanism provides buoyancy, the sinking mechanism below the collecting mechanism provides sinking gravity, the controller controls the releasing component of the sinking mechanism to release the sinking balancing weight through a received signal of a depth sensor, the collecting mechanism floats upwards, meanwhile the controller controls opening and closing of the opening and closing component, therefore, the collecting mechanism is controlled to collect the plankton, and the plankton can be accurately filtered and collected in a preset collecting depth interval.

The invention discloses a practical wire cutting water tank. The water tank comprises a coarse filtering cavity, a fine filtering cavity and a purification cavity from a water inlet pipe to a water outlet pipe. The interior of the coarse filtering cavity and the interior of the fine filtering cavity are communicated through a partition plate structure between the coarse filtering cavity and the fine filtering cavity. The fine filtering cavity and the purification cavity are completely isolated through a partition plate structure between the fine filtering cavity and the purification cavity, and the fine filtering cavity and the purification cavity are communicated through a fine filtering pump arranged in the fine filtering cavity and an external water pipe. According to the practical wire cutting water tank, the structural design of the water tank is reasonable, and using and maintaining are convenient; classified filtering is achieved on scrap iron and impurities in work fluid, the quality of the work fluid is ensured, and an effective guarantee is provided for normal proceeding of wire cutting production.

The invention discloses a lubricating system of a main gear box of a wind generating set. The lubricating system comprises a circulating pump, an on-line filter, an off-line fine filter, a temperature control valve, a radiator and an oil distributor; an inlet of the circulating pump is connected with an oil outlet of the main gear box, an outlet of the circulating pump is connected with an inlet of the on-line filter, an outlet of the on-line filter is respectively connected with inlets of the off-line fine filter, the temperature control valve and the oil distributor, an outlet of the off-line fine filter is connected with an inlet of the oil distributor, an outlet of the temperature control valve is connected with the inlet of the oil distributor through the radiator, and an outlet of the oil distributor is connected with an oil return opening of the main gear box. The invention further discloses the main gear box of the wind generating set. The main gear box of the wind generating set comprises the lubricating system of the main gear box of the wind generating set. The lubricating system has the advantages that the lubricating system is simple in structure, low in cost, capable of reasonably utilizing the off-line fine filter, capable of guaranteeing the high cleanliness of lubricating oil and the like.

The invention discloses a novel recycled water production device for municipal wastewater treatment. The novel recycled water production device comprises a base, wherein a box body is arranged above the base and is fixedly connected with the base through a support; the outer end of a middle opening which is formed in the top side of the box body is fixedly connected with a lower port of a sewage ball valve; a coaxial gear is fixedly mounted at the left end of a valve rod of the sewage ball valve; a first horizontal shaft is arranged at the left end of the lower part of the box body; the rear end of the first horizontal shaft is in bearing connection with the rear-side inner wall of the box body; the front end of the first horizontal shaft passes through a preformed hole which is formed inthe front wall of the box body and is positioned on the front part of the box body; and the outer circumference of the first horizontal shaft is rotatably connected with the inner circumference of thepreformed hole through a sealing bearing. The novel recycled water production device disclosed by the invention has a simple structure and is ingenious in idea; by utilizing the gravity of the sewageas kinetic energy, classifying filtration of the sewage is realized; by using a pure mechanical structure, coordination of all sewage treatment steps is realized, and thus, the reliability is high, the pure mechanical structure is convenient to repair and the maintenance cost is low; and a filtration device can be cleaned, so that blocking of the filtration device is effectively avoided, greenness is achieved, energy consumption is avoided, and market demands can be met, and therefore, the novel recycled water production device for municipal wastewater treatment is suitable for popularization.

The invention discloses a circuit breaker. With the circuit breaker, problems of easy loosening and unstable fixation of arc-extinguishing cover fixation in the housing in the prior art can be solved. The circuit breaker is characterized in that the breaker comprises a housing; a mounting groove and an arc-extinguishing cover arranged in the mounting groove are arranged in the housing. The arc-extinguishing cover includes a cover body, a first arc-extinguishing grid plate and a second arc-extinguishing grid plate, wherein the grid plates are distributed in the cover body at intervals. Elastic abutting plates abutted against the inner walls of the mounting groove are arranged at the two opposite sides of the cover body and enable the arc-extinguishing cover to be abutted against and fixed in the mounting groove elastically, so that loosening and unstable fixation between the arc-extinguishing cover and the mounting groove can be avoided. The first arc-extinguishing grid plate and the second arc-extinguishing grid plate are distributed in the cover body at an interval and crossed arc extinguishing is carried out on the arc; and the breaking index is high, so that the arc-extinguishing effect of the arc-extinguishing cover is optimized.

The invention belongs to the field of sewage treatment equipment and particularly relates to a sewage filtering device for food processing. The sewage filtering device comprises an upper base plate, alower base plate, side plates, a controller, a first-stage filtering unit and a second-stage filtering unit, wherein the upper base plate is arranged on the lower base plate by the side plates; the first-stage filtering unit is connected with a sewage inlet in the side plate through a pipeline; the second-stage filtering unit is positioned on the left side of the first-stage filtering unit; a first hairbrush unit is arranged on a sliding block of a rodless air cylinder through an air pressure rod and is positioned on the left side of a second hairbrush unit; the rodless air cylinder is fixedon the lower surface of the upper base plate; the first hairbrush unit comprises a first-stage plate, a second-stage plate, second-stage air pressure rods and hairbrushes; the second-stage plate is connected with the first-stage plate through the air pressure rod; and hairbrushes are uniformly arranged between the first-stage plate and the second-stage plate. The sewage filtering device disclosedby the invention is mainly used for graded filtering of sewage produced by a slaughter house and differentiated recovering of the sewage in the slaughter house; and the utilization rate of resources is improved while the labor cost is reduced.

The invention discloses a horizontal-type double-drum backwashing filter. The horizontal-type double-drum backwashing filter comprises a left side cover plate, a right side cover plate, a coarse filtering drum filter screen, a large particle collecting tank, a fine filtering drum filter screen, a sludge and sand collecting tank, a negative pressure water outlet, a high pressure water inlet, a high pressure jet pipe, a toothed belt, and a driving wheel; the horizontal-type double-drum backwashing filter is placed in water; sewage is delivered through the coarse filtering drum filter screen and the fine filtering drum filter screen successively for filtering; the high pressure jet pipe is arranged to be vertical to water surface, and is used for backwashing of the parts of the coarse filtering drum filter screen and the fine filtering drum filter screen above the water surface; large particle impurities are collected by the large particle collecting tank on the coarse filtering drum filter screen, and small particle impurities such as sludge and sand are collected by the sludge and sand collecting tank on the fine filtering drum filter screen; the drum filter screens are driven by the driving wheel to rotate so as to realize repeat backwashing of the filter screens using the high pressure jet pipe.

The invention discloses a quick grinding device for making sugar through stevia rebaudiana. The quick grinding device structurally comprises a view window, hinges, a protection door, a feed inlet, a crusher, a drive motor, portable handles, protection door lock catches, a grinding tank, a supporting frame and fixing pull rods. The quick grinding device has the beneficial effects that two grindingplates are arranged, a transverse rod is fixed to the middle of a drive swing frame in a buckled mode, positioning of the swing axis is achieved, and then grinding blocks are driven to cooperate withthe grinding plates for grinding; and the middle of a gear rack is engaged with a drive gear, the bottom of the gear rack drives the swing frame to swing accordingly, and steel wire ropes are connected to the two ends of the gear rack, so that a storage basket and a screen are driven to shake to achieve graded filtering, dual-station grinding is achieved, graded filtering can be carried out automatically, and processing procedures are reduced while the processing efficiency is improved.

The invention relates to the field of pet products, in particular to a multi-layer filter core water feeder, which comprises a hollow main body and a base seat, wherein an inner cavity is formed in the hallow main body; the base seat is used for connecting a power supply; the base seat is arranged below the main body; the top of the inner cavity of the main body is opened and a filter hole plate is arranged at the opening, and a water passing hole is formed in the filter hole plate; a water pump is arranged at the bottom of the inner cavity of the main body, a water outlet pipe is connected tothe upper end of the water pump, the water outlet pipe extends upwards to the outside of the main body, and a water outlet is formed in the upper end of the water outlet pipe; a receiving disc is sleeved to the water outlet pipe and is sleeve below the water outlet; a filtering structure is arranged below the filter hole plate; an upper cover and a filter core unit are sequentially arranged on the filtering structure from top to bottom; the filter core unit is provided with at least two layers to form a multi-layer filter core unit; and a driving device for controlling the filter core unit isfurther arranged on the main body. The filter core unit can rotate, and when one layer of the filter core unit fails or the effect drops, the filter core unit can rotate in time to filter water by using a new and effective filter core unit.

The invention discloses a domestic sewage recycling device and a use method of the device. The device comprises a treatment box, wherein the interior of the treatment box is divided into an oil spilling tank, a settling tank, a buffer tank and a sterilization tank; the two ends in the oil spilling tank are fixedly connected with an oil spilling plate and a first spilling plate; an oil outlet pipeis arranged at the left side end of the oil spilling tank; the oil spilling tank is further internally equipped with an electric heating pipe; second spilling plates are fixed at the two ends in the settling tank respectively; a sterilization device is mounted at the top of the treatment box and comprises ultraviolet lamp tubes; the ultraviolet lamp tubes extend into the sterilization tank; and apurified water outlet is formed on one side of the sterilization tank. Floating oil and excessive sewage can automatically spill through the oil spilling plate; graded filtration of the sewage can beachieved; a sewage filtration effect is improved; under irradiation of the ultraviolet lamp tubes, clean water filtered in the sterilization tank can be sterilized; the storage time of a water body isprolonged; and bacterial breeding is avoided.

The invention discloses a sewage treatment device, and belongs to the technical field of sewage treatment. A water inlet is formed in the upper end of one side of a sewage treatment tank, a water outlet is formed in the bottom of the other side of the sewage treatment tank, an end cover is arranged at the top of the sewage treatment tank, and openable cover bodies are installed on the two sides ofthe end cover. The filtering mechanism comprises a driving motor, a shaft rod and a filtering disc; the shaft rod comprises a screw rod end and a polish rod end; the filter disc comprises a base plate and a filter screen disc, the filter screen disc is connected to the screw rod end of the shaft rod, the base plate is connected with the polished rod end of the shaft rod in a penetrating mode, anda centrifugal device is further arranged in the sewage treatment box. According to the sewage filtering device, sewage impurities are filtered in a graded mode, the purpose of sewage stirring and filtering is achieved, the situation that the sewage treatment efficiency of the whole filtering mechanism is affected due to blockage of the filtering net disc can be effectively avoided, the whole filtering mechanism is simple in structure, convenient to operate and convenient to install, and the sewage treatment efficiency is greatly improved.

The embodiment of the invention discloses an efficient tea oil filter and purifying device and purifying process. The device comprises a filter tank, a crude oil tank and a rack; the filter tank is arranged at the upper end of the rack; the crude oil tank is arranged at the top of the filter tank; the device also comprises a filter mechanism, a rotating motor, a slag discharging opening, an oil collecting tank, a vacuum circulating device and a cleaning mechanism which are arranged on the filter tank. The filter mechanism is vertically arranged in the filter tank; the rotating motor is arranged at the bottom of the filter tank; an output shaft of the rotating motor upwards extends into the filter tank and is in transmission connection with the filter mechanism; the lower part of the filterbox is provided with the slag discharge opening; the oil collecting tank is further arranged on the rack, the oil collecting tank is communicated with the filter tank and connected with one end of the vacuum circulating device, the other end of the vacuum circulating device is connected with the upper portion of the filter tank, and the cleaning mechanism is further arranged on the output shaft of the rotating motor and arranged at the bottom in the filter tank. The efficient tea oil filter and purifying device is simple in structural design and convenient to use, the coarse oil filtering efficiency is greatly improved, and meanwhile the self-cleaning function of the filter mechanism is achieved.

The invention discloses a classified filtering engine oil filter assembly for a motorcycle engine. The classified filtering engine oil filter assembly comprises a filter rotor, a filter cover and a crankshaft oil pass pipe. A filtering partition plate is arranged in a cavity of the filter rotor. The edge of the filtering partition plate is fixedly installed between the filter cover and the end face of the filter rotor. The middle portion of the filtering partition plate is hunched in the direction away from the crankshaft oil pass pipe so that a secondary scrap containing cavity can be formed in the hunched portion. Space between the other parts of the filtering partition plate except for the hunched part and the filter cover forms a primary scrap containing cavity. A plurality of primary oil pass holes paired with the primary scrap containing cavity are uniformly formed in the circumference, close to the edge, of the filtering partition plate. Secondary oil pass holes paired with the secondary scrap containing cavity are formed in the center position, corresponding to the bottom of the secondary scrap containing cavity, of the filtering partition plate. By means of classified filtering, the lubricating oil impurity separation effect is improved, and the engine can work better in the lubricating working state of the lubricating oil.

The invention discloses a segmented treatment vertical sewage treatment device. The vertical sewage treatment device comprises a vertical type treatment tower, wherein a plurality of horizontal partition plates are sequentially arranged in the treatment tower from bottom to top at intervals and the inner cavity of the tower is divided into a plurality of processing chambers; the adjacent processing chambers are connected through a communicating pipeline to form a serpentine walking path, a water inlet is formed in the processing chamber at the bottommost side, and a water outlet is formed in the processing chamber at the uppermost side; a bypass pipeline is further connected to a bypass pipeline, and a bypass switch valve is arranged on the communicating pipeline and the downstream of theconnecting portion of the bypass pipeline, and each processing chamber is provided with a sewage filtering device, when sewage treatment is carried out, sewage is fed from the water inlet and is discharged from the water outlet; when the sediment is cleaned, clean water is cleaned from the water outlet and is discharged from the water outlet. The device has the advantages that the occupied area issmall, the centralized degree is high, the sewage can be treated in a segmented mode, and the self-cleaning function is achieved.

The invention discloses a closed vibration screen. The closed vibration screen comprises a base, a support, a feeding port and a screen body. The screen body is fixed to the base through the support, and the feeding port is formed in the upper end of the screen body. The closed vibration screen is characterized in that vibrators are arranged on the side wall of the screen body and further connected with the support; and a sealing cover is arranged above the screen body, and a vibration motor is arranged on the sealing cover; a filtering sieve is arranged in the screen body, a fine sand outlet and a coarse sand outlet are formed below the screen body, and a conveying belt is arranged below the coarse sand outlet. According to the closed vibration screen, the vibration motor drives the screen body to vibrate through the vibrators, classification of sandstone along the filtering sieve is accelerated, and classified filtering of coarse sand and fine sand is achieved. The vibration screen has the beneficial effects of being simple in structure, small in size, low in production cost and good in screening effect. A sealed structure is adopted, raise dust generated during working can be effectively reduced, and a certain environment protection function is achieved.

The invention discloses a vertical sewage processor with self-cleaning function, which comprises a vertically arranged treatment tower, in which a plurality of horizontal partitions are arranged at intervals from bottom to top, and the cavity in the tower is divided into multiple Processing chambers; adjacent processing chambers are connected by connecting pipes to form a serpentine walking path, wherein the lowermost processing chamber is provided with a water inlet, and the uppermost processing chamber is provided with a water outlet; each processing chamber has A sewage filtering device is provided, and the sewage filtering device includes a plurality of filter plate frames arranged at intervals along the direction of the water flow, and the filter plate frames in each treatment chamber are inclined to one side toward the water flow; during sewage treatment, from the inlet Sewage is fed into the water outlet and discharged from the water outlet; when sediments are cleaned, cleaning water is fed from the water outlet and discharged from the water outlet. The invention has a small footprint and a high degree of centralization, can effectively treat sewage, and realizes the self-cleaning function.

The invention relates to a method for suppressing amplitude-preserving and fidelity linear coherent noise and a processing terminal. The method includes the following steps: step 1: obtaining a common shot point gather and formation velocity; step 2: performing spherical diffusion compensation to obtain spherical diffusion compensation The final common shot point gather A_shot; Step 3: Filter the A_shot F-K domain inclination angle to obtain N_shot; Step 4: Perform adaptive subtraction method on A_shot and N_shot to attenuate the noise to obtain R_shot; Step 5: Perform dynamic correction on N_shot , to get the Nnmo_shot after dynamic correction; Step 6: Extract linear coherent noise Nrem_shot from Nnmo_shot; Step 7: Carry out adaptive subtraction method to attenuate the noise according to Nnmo_shot and Nrem_shot, and obtain the residual effective signal common shot gather Rrem_shot; Step 8 : Perform reaction correction on Rrem_shot to obtain the residual effective signal Rremnmo_shot; Step 9: Add back to obtain the effective signal shot set Rall_shot with amplitude preservation and fidelity; Step 10: Perform inverse spherical diffusion compensation on the effective signal shot set Rall_shot to obtain suppressed linear coherence Common shot gathers after noise. The invention can effectively suppress linear coherent noise with amplitude preservation and fidelity.

The invention discloses an upright sewage processor with a self-cleaning function. The upright sewage processor comprises an upright processing tower, multiple horizontal clapboards are spaced in theprocessing tower from bottom to top in sequence, and a cavity in the tower is divided into multiple processing chambers; every two adjacent processing chambers are connected into an S-shaped walking path through a communication pipeline, a water inlet is formed in the processing chamber located at the lowermost side, and a water outlet is formed in the processing chamber located at the uppermost side; each processing chamber is internally provided with a sewage filtering device, each sewage filtering device comprises multiple filtering plate frames which are spaced in sequence in the directionof water current, and the filtering plate frames in each processing chamber all tilt in the incoming direction of the water current; when sewage needs to be treated, the sewage enters the water inletand is drained out of the water outlet; when sediment needs to be cleaned away, cleaning liquid enters the water outlet and is drained out of the water outlet. The upright sewage processor has a small occupied area and a high centralized degree, can effectively process the sewage, and achieves the self-cleaning function.

The invention discloses an environment-friendly dust-collecting room for a grain dryer, which comprises a box body (1). The box body (1) is equipped with an upper chamber (1.1) and a lower chamber (1.1). The filter group of the chamber (1.2), the lower chamber (1.2) is provided with an inlet (1.3), and the upper chamber (1.1) is provided with a filter for the waste gas in the lower chamber (1.2) to be discharged after passing through the filter group. The outlet (1.4) is characterized in that the filter group includes a primary filter and a top filter mechanism (5) arranged above the primary filter. The invention provides an environment-friendly dust collection room for a grain dryer, which can efficiently filter the waste gas discharged from the grain dryer, thereby removing dust particles and impurities in the waste gas.

The invention relates to a purification assembly and a filtering device applying the purification assembly, the purification assembly comprises a first filter screen made of a PET material, a second filter screen with electrostatic charges and a third filter screen capable of releasing negative ions, the first filter screen, the second filter screen and the third filter screen are stacked in sequence, and the third filter screen comprises a nano fiber structure prepared through electrostatic spinning. Anion powder is added into a spinning solution for spinning the third filter screen. Negative ion powder is added into the spinning solution for spinning the third filter screen, air around the negative ion powder is ionized, negative ions are formed, bacteria in the air are killed, people feel relaxed and happy, and the negative ions can be generated without high-voltage electricity; and moreover, the negative ions can be subjected to electret again on the second filter screen with electrostatic charges while being generated, so that the static electricity can be supplemented again after the static electricity of the second filter screen is lost, and the filtering efficiency of the particulate matters and the dust holding capacity of the particulate matters are greatly improved.