108results about How to "Uniform circulation" patented technology

The invention relates to the technical field of air filtering, in particular to a graphene material coating and a preparing method thereof, and further relates to an a air filtering device and system based on the graphene material coating. The preparing method of the graphene material coating includes the following steps that S1, slurry-dispersion raw liquid is prepared, wherein a dispersing agent and a bonding agent are added into a solvent, and the mixture is stirred to generate the slurry-dispersion raw liquid; S2, a graphene surface coating is formed, wherein graphene powder is added into the slurry-dispersion raw liquid, the mixture is stirred to allow slurry to be even to be applied to the surface of a carrier, drying is carried out, and the graphene-material-coating finished product is obtained. By means of the graphene material coating and the preparing method thereof, the adsorption rate of hazardous substances in gas can be increased, and secondary pollution caused by unfirm adsorption is avoided.

The invention relates to a steam sterilizing process for the disinfection of medical appliances in hospital, and the steam sterilizer employing the steam sterilizing process, which comprises the steps of vacuumizing, preheating, sterilizing and cooling down. The steam sterilizer comprises a steam sterilizing box, a valve group, an air filter, a steam generator, a vacuum pump and an automatic control system.

The invention relates to an energy-saving explosionproof drying furnace and a monitoring system thereof. The drying furnace is provided with a furnace body, a heating element, a trolley and a chimney, wherein the furnace body is provided with a heating chamber body; the top of the furnace body is provided with a circular hot-air generator; the heating element is positioned in the heating chamber body; the chimney is sleeved with a preheating sleeve communicated with the heating chamber body; and the bottom of the furnace body is provided with a trolley lifting mechanism. The furnace has a rational and novel structure, a unique air channel design, and is provided with the complete drying automation monitoring system, thereby having the advantages of high heat energy utilization rate, convenient operation, labor conservation and quick drying speed, ensuring that the whole drying process is effectively monitored and maintained in an optimal running state, particularly effectively eliminating the hidden trouble of a burning and explosion accident and effectively guaranteeing the safety of a person and equipment.

The invention provides a temperature-control component as well as a battery module and a battery box. The temperature-control component comprises at least one substrate and fins, wherein the substrate is pasted to the wall surface of a unit battery so as to conduct heat; the fins are in heat conduction connection with the substrate; the temperature control component further comprises a heating device for heating the fins and / or the substrate so as to raise the temperature of the unit battery; the outer side of the temperature-control component is tightly pasted to the outer wall of the unit battery, thereby forming the battery module; the battery module, an upper cover and a box body form the battery box provided by the invention. The temperature-control component provided by the invention is connected with different unit batteries in a sufficient contact manner, and the temperature of the battery module is controlled through air cooling heat radiation and heating of heating elements, so that the problem that a common battery box is low in working efficiency in a low-temperature environment because of absence of the heating elements is solved.

The invention discloses a battery heating system of an electric automobile, and aims to provide a battery heating system which is uniform in heat distribution, high in heating efficiency and good in heating consistency for each battery module. The battery heating system comprises a plurality of mounting plates and a plurality of groups of battery modules, wherein a plurality of single batteries are arranged in each battery module; the battery modules are arranged in the corresponding mounting plates respectively, and are fixed in a battery box through the mounting plates; a plurality of electric heating plates are arranged in each battery module, and each electric heating plate is arranged between every two adjacent single batteries respectively; a heat transfer heat-conducting fin is arranged between each mounting plate and each battery module, the upper surface of the heat transfer heat-conducting fin is jointed with the bottom surface of each single battery in each battery module, and the lower surface of the heat transfer heat-conducting fin is jointed with the inner bottom surface of each mounting plate; and a soaking heat-conducting fin is arranged below each mounting plate, and the outer bottom surface of each mounting plate is jointed with the upper surface of each soaking heat-conducting fin.

The invention provides a fuel cell gas diffusion layer structure and a processing method thereof, a gas diffusion layer is a substrate layer close to one side of a bipolar plate, and the surface of the gas diffusion layer is provided with a plurality of mutually staggered and communicated groove textures, the cross section area of the groove texture in the flowing direction in the groove textureswhich are communicated in a staggered mode is gradually increased and then gradually reduced in the flowing direction, wherein the areas of the cross sections of the two ends of the groove texture inthe flow direction are gradually changed, the area of the cross section of the middle of the groove texture in the flow direction is kept unchanged, and the area of the cross section in the middle ofthe groove texture is 1.5-3 times of the minimum area of the cross sections at the two ends. The trench texture can enable liquid water to leave the cathode, eliminate the electrode flooding phenomenon, allow a proper amount of water to wet airflow, and keep the membrane electrode wet.

The invention provides a preparation method of high-nitrogen vanadium nitride. The preparation method comprises the following steps: (1) vanadium oxide, a carbon reducing agent and water are mixed and pressed to prepare pellets; (2) the prepared pellets are put in a vertical medium-frequency furnace; nitrogen with a flow of 80-200 m3 / h is introduced; and the pellets move in the vertical medium-frequency furnace from top to bottom, are reacted by a heating section in the vertical medium-frequency furnace, and are cooled by a cooling section to prepare vanadium nitride. The preparation method adopts the vertical medium-frequency furnace to supply the stable reaction atmosphere and reaction process, uses the valence state of vanadium in vanadium oxide as basis for precisely controlling the carbon content in the product, can reduce the ratio of carbon in the product to the greatest extent, guarantees the promotion space of the nitrogen content in the product, and prepares high-nitrogen vanadium nitride through controlling such process conditions as fresh pellet quality, reaction temperature in each phase and nitrogen flow.

The invention discloses a gas circulation type growth chamber used for three-dimensionally planted edible mushrooms. The gas circulation type growth chamber includes a growth chamber body, axial-flow draught fans, connecting cylinders, an edible mushroom suspension device and a filtering device; the inside of the upper side of the growth chamber body is fixedly connected with the edible mushroom suspension device through a connecting column, the axial-flow draught fans are fixedly installed on the upper portion of the growth chamber body in a bilateral symmetrical mode, and the lower portions of the axial-flow draught fans are fixedly connected with the connecting cylinders which fixedly penetrate through the wall boy of the upper side of the growth chamber body. The growth chamber has the advantages that when more suspended pollutants are attached to the inner wall of a filtering net, a pressure valve is opened, the suspended pollutants attached to the filtering net are absorbed through dust absorption holes in a conical barrel and then enter a dust absorption barrel, the adsorbed suspended pollutants are injected to a collection box under the effect of a connecting pipe, therefore, regular cleaning is not needed for the inner wall of a filtering cylinder, the working time is saved, the working intensity is reduced, the structure is simple, the air filtering effect is significant, and gas circulation in the growth chamber body can be maintained.

The invention provides an active carbon adsorption regenerator, and a waste gas treatment line equipped with same. The adsorption regenerator includes an adsorption chamber, in which an active carbonaccommodating frame is located, active carbon placed in the active carbon accommodating frame. A vapor generator is connected to the lower part of the adsorption chamber and includes a liquid chamber,in which a heater is arranged. The vapor generator is also connected to a blower which blows vapor to the active carbon. The invention also provides the waste gas treatment line equipped with the adsorption regenerator, which includes, in a successively connected manner, a condenser, a sprayer and a photo-catalytic oxidizer. A gas inlet of the adsorption regenerator is connected to the photo-catalytic oxidizer while a gas return port is connected to the condenser. During use of the adsorption regenerator, the active carbon is unnecessary to move, and can be regenerated in manners of solvent dissolution, vapor blowing dissolution and hot air blowing. During use of the waste gas treatment line, the units are combined in order to gradually treat pollutants in waste gas with a better treatment effect.

The invention relates to a filter device for filtering fluid media, comprising a housing (1) for accommodating a filter element (3) in an accommodation cavity (2), the filter element (3) divides the accommodation cavity (2) into an inflow cavity (4) and an outflow cavity (5) divided into a master cavity (5a) and a slavery cavity (5b) by a partition (6) at least partially movable, and the master cavity (5a) and the slavery cavity (5b) are flowably connected. The invention aims to provide a filter device capable of optimizing the air supply of an internal combustion engine after long running time at low cost, characterized in that the partition (6) has a working surface (6a), a force generated by a pressure difference between the inflow cavity (4) and the outflow cavity (5) can be applied to the working surface, such that the flowable connection between the master cavity (4) and the slavery cavity (5) can be formed directly by the force.

The present invention discloses a power distribution cabinet with a good heat dissipation effect, pertaining to the technical field of power equipments. The power distribution cabinet comprises a cabinet body, a controller arranged in the cabinet body, a temperature control system electrically connected with the controller, and a humidity control system, wherein the humidity control system is arranged in the cabinet body and the humidity control system is electrically connected with the controller. The temperature control system comprises a temperature sensor arranged on the inner wall of oneside of the inside of the cabinet body; a refrigerating box, wherein the refrigerating box is arranged close to the cabinet body and the refrigerating box is connected with the cabinet body; and heatdissipation components arranged on the bottom of the inner wall of the cabinet body. The middle part of the refrigerating box is provided with a partition plate. A refrigerating part is located on theupper end of the partition plate, in the refrigerating box. A heat dissipation part is located under the lower end of the partition plate, in the refrigerating box. The refrigerating part comprises abox body, wherein the box body is arranged at the lower end of one side of the cabinet body and the box body is connected with the cabinet body; an evaporator, wherein the evaporator is arranged in the box body and the evaporator is used for refrigerating; a cold air fan used for inducing air; and a cold air motor used for driving the cold air fan. The power distribution cabinet can be used for refrigeration and dehumidification, and the power distribution cabinet has the advantages of convenience for using and good heat dissipation effect.

The invention discloses a hand drier, which comprises a shell, an air guide duct and a dynamical structure, wherein the shell is provided with an air inlet; the air guide duct is arranged on the shell and comprises two induced pipes and an annular discharge pipe; the two end parts of the discharge pipe extend towards each other; the lower ends of the two induced pipes are respectively communicated with the inner part of the shell; the upper ends of the two induced pipes are respectively connected with the two end parts of the discharge pipe; a plurality of air outlets are formed in the inner peripheral wall of the discharge pipe and comprise left side air outlets and right side air outlets; the dynamical structure is formed in the shell, operates to guide air into the shell from the air inlet and guides the air in the shell to each induced pipe. According to the hand drier provided by the invention, the hand drying area is roomier, the phenomenon that hands of a user touch the discharge pipe when being dried can be avoided, the air speed of the air outlet is improved favorably, and the hand drying time of the user is reduced.

The invention belongs to a container steam heating device. In order to solve the technical problem that an extra-tank heating system of a tank container in the prior art is low in heating efficiency and insufficient in heating balance degree, and condensed water generated by a heating pipeline in a low-temperature environment is poor in circulation, a tank container steam heating device is provided. The tank container steam heating device comprises an arc-shaped shell and an arc-shaped heating cover plate, the shell is arranged outside the heating cover plate in a sleeving mode, a cavity is formed between the shell and the heating cover plate, a steam inlet channel, a steam outlet channel and a plurality of cavity partition plates are arranged in the cavity in the circumferential direction, the plurality of cavity partition plates are located between the steam inlet channel and the steam outlet channel to divide the cavity into a plurality of heating areas which sequentially communicate with one another, steam passing holes and condensed water passing holes are formed in the inner side of the steam inlet channel, steam passing holes and condensed water passing holes are formed in the cavity partition plates, steam passing holes and condensed water passing holes are formed in the inner side of the steam outlet channel, and condensed water discharge ports are formed in the outerside of the steam outlet channel.

The invention provides a biomembrane unit. The biomembrane unit comprises a support board provided with a plurality of raised strips and membrane cloths fastened to the support board, a water chute is formed between adjacent raised strips, and each of the raised strips is provided with through holes connecting two surfaces of the support board. The invention also provides a membrane bioreactor comprising the biomembrane unit. Each of the raised strips is provided with through holes for the mutual flow of clear water on two surfaces of the support board, so when clear water penetrating one of the membrane cloths is more than clear water penetrating the other one of the membrane cloths, the clear water penetrating the one of the membrane cloths can enter the water chute on the other surface because of a water pressure difference, and the water chute on the other surface is fully utilized to make the water smoothly and uniformly flow and the water output stable.

The invention discloses an intelligent building air environment monitoring management system. The management system comprises a dynamic sampling system, an environment adjusting system, an abnormal early warning system and a terminal control system. A real-time parameter value of the air quality in each area of a building environment is acquired in a form of dynamic circulation, so that detected air is ensured to circulate uniformly and the detection accuracy is high; by acquiring parameters such as the content of particulate matters, harmful gas and microorganisms in the air, the temperatureand humidity and the smoke condition, the air environment can be comprehensively monitored; according to detected data, corresponding air environment adjustment can be performed to control the air environment to be in a safe and healthy state; an abnormal state is reminded in advance by utilizing the abnormal early warning system, so that corresponding measures can be taken in time; and through the terminal control system, the air quality and the operation condition of related equipment are known in real time, so that macroscopic regulation and control are facilitated and a green and healthy construction environment can be created.

The invention provides a heating light box of blow molding machine for heating material embryo, comprising heating device and cooling device. The heating device used to heat material embryo comprises several semi-closed first boxes and several heating body set on first boxes. The cooling device blows air to the heating device so that material embryo heated in the heating device is blown so as to make material embryo cool appropriately. The cooling device comprises several second boxes and at least a blower set on said second box. By adopting the heating light box in invention blow molding machine can increase heating efficiency obviously and air circulation in light box is evener. The mouth part of bottle embryo can be cooled better and energy is saving.

The invention provides a reverse air inlet heat dissipation method of bank self-service equipment. An air blower is used for heat dissipation in the mode of blowing air into the equipment. As the air blower blows air into the equipment, positive pressure is generated inside the equipment, the air pressure inside the equipment is higher than that of the external environment, the air inside the equipment flows from the seam of an outer shell of the equipment and an air outlet of a panel to the external environment for heat dissipation, a replaceable filtering net is arranged at an air inlet portion on the outer side of the air blower, the air entering the equipment passes through the filtering net in a concentrated mode, and dust is adsorbed and filtered in a concentrated mode, so that it is guaranteed that the air entering the equipment is free of dust and the dust is prevented for polluting elements inside the equipment. Meanwhile, the filtering net can be replaced and cleaned conveniently.

The invention discloses a high-pressure elbow. Guide impellers are arranged on an inner wall of the elbow; multiple levels of guide impellers are arranged in the medium flow direction of the elbow uniformly at intervals, and in any level of guide impellers, and multiple groups of guide impellers are arranged in the radial direction of the elbow uniformly at intervals; the radial size of each guide impeller in the elbow is 1 / 4-1 / 3 of that of the elbow; blades are made of impact-resistant metal materials; the uniform spaced distance of the multiple levels of guide impellers in the medium flow direction is 1-3 times the radial size of the elbow; the uniform spaced distance of the multiple levels of guide impellers in the radial direction of the elbow is 1 / 4-1 / 2 of the outer peripheral arc length of the elbow; a thickened wear resisting layer is arranged on the peripheral side of the elbow. The guide impellers are arranged in the elbow, orderly dredge high-pressure fluid media, bear a part of stress of flushing of the high-pressure fluid media and facilitate uniform circulation of the media; besides, the thickened wear resisting layer is additionally arranged on the peripheral side of the elbow, and the service life of the elbow is further prolonged.

The invention relates to an epoxy resin electric power insulator casting molding method, which comprises a workbench, a fixing device, a first mold, a second mold and a moving device, and is characterized in that the fixing device comprises a placing groove, a driving motor, a circular rod, an annular plate, an annular clamping groove and a clamping frame; through cooperation of the workbench, the fixing device, the first mold, the second mold and the moving device, firstly, the first mold and the second mold of the epoxy resin electric power insulator needing to be subjected to casting molding are rapidly closed through the fixing device, so that traditional tedious mold closing and demolding are avoided, and the mechanical adaptability and working efficiency are improved; and the mold cavity is poured through the moving device, and the molten resin material can uniformly flow to the whole edge structure of the mold cavity through the matching of the fixing device, so that the qualified rate of the machine is improved.

The invention provides a power device protective chip which comprises a substrate, a first epitaxial layer formed on the substrate, rectification areas formed in the first epitaxial layer separately,and an isolation area positioned between the two rectification areas and extending from the upper surface of the first epitaxial layer to the substrate; each rectification area comprises a first trench formed from the upper surface of the first epitaxial layer to the first epitaxial layer, a second trench formed from the bottom of the first trench to the first epitaxial layer, and a third trench formed the bottom of the second trench to the first epitaxial layer, the first, second and third trenches are communicated, the widths of the first, second and third trenches are decreased successively, and Schottky barrier heights between metal layers in the first, second and third trenches and the first epitaxial layer are reduced successively; and the isolation area comprises a fourth trench, aninjection region positioned in the bottom of the fourth trench and a second epitaxial layer formed in the fourth trench. The invention also provides a preparation method of the power device protective chip. The reliability is improved, the packaging area is reduced, and the cost is reduced.

The invention discloses an automobile exhaust manifold silencer which comprises a main body, an air inlet pipe and an end cover. A silencer core body is fixed in the main body, and both ends of the silencer core body run through the end part of the main body and the middle part of the end cover. An annular groove is arranged in the open end face of the main body. An extension part which matches the annular groove is arranged in the middle part of the seal end of the end cover. An inclined face A is arranged at the upper part of the seal end face of the end cover. An inclined face B which shares the same inclination direction with the inclined face A is arranged on the end face of the main body. The inclined face A, the outer wall of the extension part and the inclined face B form an annular filling groove. The end part of the silencer core body is in butt joint with an intake pipe. A helical diversion trench is arranged in the inner wall of the intake pipe in the direction, which points to the main body, of the axis. On the seal end face of the end cover, an L-shaped contact face is formed on the outer wall between the extension end and a projection. Through a metal adhesive in the filling groove, the outer wall is completely separated from the inside of the main body to ensure that the airtightness of the silencer.

The invention relates to a novel anti-scouring adjusting valve which comprises a valve body, a valve deck, a valve rod, a valve element, a valve base and a throttling element. The throttling element is formed by jointly stacking a plurality of pore plate assemblies. Each pore plate assembly comprises a pore plate body, wherein the pore plate body is annular, an annular groove is formed in the lower end of the pore plate body, the annular groove is divided into two coaxial annular ducts through a partition plate, the annular ducts are the annular duct A and the annular duct B in sequence from interior to exterior, a hole A communicated with the annular duct A is formed in the inner wall of the pore plate body, a hole B communicating the annular runner A with the annular runner B is formed in the partition plate, a hole C communicated with the annular runner B is formed in the outer wall of the pore plate body, and the hole A, the hole B and the hole C are distributed in a staggered mode. The novel anti-scouring adjusting valve has the advantages that the throttling element is designed to be of the combined structure of the multiple annular runners, and the pressure and flow speed of a medium can be effectively decreased, so that the characteristic that the flow of a medium is adjusted in a balanced and stable mode is achieved, and no fluctuations are generated.

The invention relates to a redox flowing method of a vanadium redox flow galvanic pile and the galvanic pile. The redox flowing method of the vanadium redox flow galvanic pile is characterized in that each galvanic pile unit in the vanadium redox flow galvanic pile is taken as an independent vanadium redox circulating system. The galvanic pile comprises a plurality of galvanic pile units, and each galvanic pile unit is provided with the independent vanadium redox circulating system. After the technical scheme is adopted, vanadium redox is more uniform in circulation and distribution inside the galvanic pile, so that the whole electric performance and stability of the whole vanadium galvanic pile are greatly improved; each galvanic pile unit independently operates, so that the sealing effect is better.

The invention discloses an adjustable vortex type airflow drying oven and relates to the field of drying ovens. The problems that most drying ovens in the prior art cannot well control airflow, so that drying is not uniform, drying time is long, and the efficiency is not high are solved. The adjustable vortex type airflow drying oven comprises an oven body. A vortex drying cavity is formed in the oven body. The inner wall of the vortex drying cavity is provided with a plurality of air injection cavities distributed in an annular array manner. The outer walls of the air injection cavities are in an arc shape. Air injection pipes are arranged at the positions, corresponding to the air injection cavities, of the outer wall of the vortex drying cavity. A drying device, a fan and a heating device are also arranged in the oven body. A humidity sensor is arranged on a pipeline between the drying device and the fan. The inner wall of the vortex drying cavity is further provided with a temperature sensor. A man-machine visual control screen is arranged on the outer side of the vortex drying cavity. By the adoption of a vortex way, the air in the drying cavity evenly flows, hot air can bring away more moisture or other volatile liquid when entering the drying cavity, drying time is greatly shortened, and drying efficiency is improved.

The invention discloses a corrosion-resistant magnetic drive centrifugal pump. A first conveying channel is arranged on a pump cover, and a second conveying channel is arranged on a driving conveyingshaft, is arranged on the central axis of the driving conveying shaft and extends towards the rear end to extend out of the driving conveying shaft along the central axis. A conveying opening is formed on the driving conveying shaft, one end of the first conveying channel is connected to a buffer liquid storage tank, and the other end is connected with a conveying port of the second conveying channel. A third conveying channel is further formed on the pump cover, the first conveying channel and the third conveying channel both extend inwards from the outer wall of the pump cover to penetrate through the pump cover, one end of the third conveying channel is connected to the buffer liquid storage tank, and the other end communicates with an annular gap area between an isolation sleeve and aninner magnetic rotor, so that the problem that heat preservation is needed during the conveying process is solved, the media which are easy to crystallize and high in corrosivity do not enter a driving cavity, the driving shaft is protected, and the service life is prolonged; the cooling and lubricating effects are good, the driving conveying shaft achieves a good driving effect, and the volume loss is well reduced.

The invention discloses a cathode flow channel of a proton exchange membrane fuel cell for improving a water removal effect, which is characterized in that a gas diffusion layer is a substrate layer close to one side of a bipolar plate, micro-bulge textures are processed on the surface of the gas diffusion layer of the cathode flow channel, and the water logging phenomenon of a liquid reaction product is eliminated by utilizing the micro-bulge textures. The micro-convex textures are sine wave micro-textures which are parallel to one another, and the cross section area of the sine wave micro-textures in the flow direction is kept unchanged. A hydrophilic pipe structure can be processed at the top of the cathode flow channel, the hydrophilic pipe is used for removing liquid reactants on the surface of the gas diffusion layer, the cross section of the hydrophilic pipe in the flow direction is circular, and the area of the cross section is kept unchanged. The two structures can strengthen the function that liquid water leaves the surface of the gas diffusion layer, the water flooding phenomenon of the cathode of the proton exchange membrane fuel cell is remarkably improved, a proper amount of water is allowed to wet airflow, and the wettability of a membrane electrode is kept. In addition, certain advantages are achieved in the aspects of controlling the rising rate of pressure drop in the flow channel and reducing power loss.

The invention relates to the technical field of heat exchangers, in particular to a plate type heat exchanger with asymmetric channels. The plate type heat exchanger comprises a plurality of heat exchange plates stacked to form heat exchange channels, the heat exchange plates are first plates and second plates which are alternately arranged, the first plates and the second plates both comprise a main panel and surrounding baffles, a plurality of convex ridges are arranged on the main panel, a concave valley is formed between every two adjacent convex ridges, and a plurality of grooves are evenly distributed in the concave valley of the first plates, so that asymmetric channels with different volumes are formed in the two sides of the second plates. According to the heat exchanger, the multiple evenly-distributed grooves are formed in the valley of the first plates, asymmetric channels with different volumes are formed in the two sides of the second plates, the heat exchange performanceis improved, due to the arrangement of the grooves, the convex ridges of the second plates are clamped between every two adjacent grooves, the inclined planes on two sides of the convex ridges and the inclined planes on two sides of the grooves which are in contact with each other effectively increase the welding area, the pressure-bearing effect of the heat exchanger is enhanced, and the heat exchange performance and the pressure-bearing effect are both considered.

An air bag for pressing a living body, in which a problem that an arm of the user is non-uniformly pressed to give uncomfortable feeling to the user is prevented and in which measurement accuracy is increased. These are achieved by supplying air in a generally uniform way to the entire part of the air bag to totally and uniformly press the arm. The air bag (2) has a substantially rectangular air bag (22), a pipe (21) connected to the air bag (22), and a net-like sheet (23) contained in the air bag (22). The net-like sheet (23) has an upper folded part (231), a lower folded part (232), a right folded part (233), and a left folded part (234).

The invention discloses a kitchen ventilator positive pressure dust collecting system. The kitchen ventilator positive pressure dust collecting system comprises a positive pressure dust collecting binand further comprises first purification devices and second purification devices, all of which are arranged in the positive pressure dust collecting bin. The positive pressure dust collecting bin isin a cylindrical shape and is vertically arranged. The multiple first purification devices and the multiple second purification devices are arranged and are vertically arranged in a staggered manner,and a gap is formed between each first purification device and the corresponding second purification device adjacent to the first purification device. Cooking fume pollution gas enters from the lowerend of the positive pressure dust collecting bin and penetrates the first purification devices and the second purification devices, all of which are arranged in the staggered manner, cooking fume gasredistribution is formed in the gaps between the first purification devices and the second purification devices, and smoke can evenly circulate in each first purification device and each second purification device. Pollutants in cooking fume can be sufficiently adsorbed. The first purification devices and the second purification devices can be selected to be increased or reduced according to the needed smoke purification amount, and therefore the effect that the pollutants in the cooking fume gas can be completely purified can be achieved.