80results about How to "Large air volume" patented technology

The invention provides a control method of an air conditioner and the air conditioner. A first air guide assembly is arranged at an indoor air outlet of the air conditioner, the first air guide assembly is used for adjusting the longitudinal air outlet direction of the indoor air outlet, and a plurality of working positions are preset. The control method of the air conditioner comprises the steps of obtaining an air supply mode and an operation mode of the air conditioner; judging whether the air supply mode is a preset reciprocating air supply mode or not; if yes, according to the operation mode, the preset staying duration of the first air guide assembly at each working position is determined; and the first air guide assembly is controlled to swing in a reciprocating mode and stays at each working position for the corresponding preset staying duration. According to the air conditioner control method, the air conditioner can correspondingly adjust the preset staying duration of the first air guide assembly staying at each working position according to the running mode when air is supplied in a reciprocating mode, so that the uniform temperature adjusting effect of the air conditioner on all positions of a room is better.

The utility model provides a fan and a ventilation device.The fan comprises a first cover plate, a second cover plate and a plurality of fan blades, the first cover plate is annular, and a first ventilation opening is formed in the inner side of the first cover plate; the second cover plate and the first cover plate are oppositely arranged at an interval, and a second ventilation opening is formed between the outer edge of the second cover plate and the outer edge of the first cover plate; the multiple fan blades are arranged between the first cover plate and the second cover plate at intervals around the center line of the first ventilation opening. The ends, close to the center of the first ventilation opening, of the fan blades extend into the first ventilation opening, so that the ends, close to the first ventilation opening, of the fan blades can be set to be high, the area of the fan blades is large, and the air volume is increased; and the end, close to the center of the first ventilation opening, of each fan blade is in the step shape with the height gradually increased in the direction from the center of the first ventilation opening to the edge of the first ventilation opening, noise can be effectively reduced, and therefore the fan is low in noise while having large air volume.

The air conditioner indoor unit comprises a machine shell, a first air outlet channel and a second air outlet channel are arranged in the machine shell, the first air outlet channel is provided with a first air outlet formed in the machine shell, and the second air outlet channel is provided with a second air outlet formed in the machine shell; the flow dividing structural part is arranged on the machine shell, the flow dividing structural part is provided with a first flow dividing face and a second flow dividing face, the first flow dividing face is used for guiding airflow to the first air outlet, and the second flow dividing face is used for guiding airflow to the second air outlet; the switching part is rotatably arranged on the flow dividing structural part, the switching part has a first state, a second state and a middle state, the switching part shields the first air outlet channel in the first state, the switching part shields the second air outlet channel in the second state, and the first air outlet channel and the second air outlet channel are both communicated in the middle state. According to the air conditioner indoor unit, the first air outlet and / or the second air outlet can be selected for air outlet, and the air outlet modes of the air conditioner indoor unit are increased.

The utility model provides a drying air duct structure which is applied to a clothes drying device, the clothes drying device comprises a drying cylinder, a clothes drying cavity is formed in the drying cylinder, the clothes drying cavity is provided with an airflow inlet and an airflow outlet, and the drying air duct structure is communicated between the airflow inlet and the airflow outlet. The drying air duct structure comprises a rear cover plate and a back plate which are buckled together front and back to form the drying air duct structure, and two air inlets are located in the lower portion of the drying air duct structure and used for introducing hot air from a heating source into an air duct cavity of the drying air duct structure. When the back plate and the rear cover plate are buckled together front and back to form a drying air duct structure, the first volute structures and the second volute structures are matched together in a one-to-one correspondence mode to form two volute air ducts. The two volute air ducts are in one-to-one correspondence with the two air inlets so as to be respectively provided with an impeller for introducing hot air from a heating source into the air duct cavity of the drying air duct structure; and the air supply direction of the air supply outlet of each volute air duct faces the air outlet of the drying air duct structure.

The utility model provides a kind of high-speed fan, including: motor assembly;Fan shell, sleeve joint motor assembly, the direction of the air flow produced by the outer periphery of cooperation motor assembly is formed into air inlet end and air outlet end respectively, the surface of motor assembly located at air outlet end is equipped with several self central outward helical extension's air deflector;Annular air inlet cover, connect the air inlet end of fan shell;And arc air outlet cover, connect the air outlet end of fan shell, the outer wall of fan shell, the inner wall of arc air outlet cover is divided by air deflector and is formed into several helical air ducts arranged in ring, air flow produced by motor assembly is shunted as sub-air flow by helical air duct, and sub-air flow is independently emitted outward from the air outlet opening in the center of arc air outlet cover.The utility model can improve air duct structure, effectively increase the air output of fan under the premise of constant motor power, and improve the effect of silence.

The utility model discloses a duct type air conditioner and an air conditioner. The duct type air conditioner comprises a shell, a first mounting area, a second mounting area and a third mounting area are sequentially arranged in the shell; the heat exchanger is arranged in the first mounting area; the fan is arranged in the third mounting area, and an air inlet of the fan faces the second mounting area; the acoustic superstructure is located in the second installation area and located on the periphery of the air inlet of the fan, and an air passing channel is formed among the sound absorption face of the acoustic superstructure, the side, facing the second installation area, of the heat exchanger and the air inlet of the fan. When the wind pipe machine runs, indoor air flows to the wind passing channel after being subjected to heat exchange through the heat exchanger and then is blown back into a room through the fan, the acoustic superstructure is located on the periphery of the air inlet of the fan, so that the acoustic superstructure does not affect air inlet of the air inlet of the fan, and in the process that a wind beam passes through the wind passing channel, the wind beam is not affected. The noise in the wind beam can enter the acoustic superstructure from the sound absorption surface of the acoustic superstructure to reduce the noise, so that the ducted air conditioner has the advantages of low noise, large air output and good overall performance.

The utility model relates to a kind of hot exhaust gas recovery circulation devices of mobile air conditioner, it mainly is in mobile air conditioner inside is equipped with a circulating device and the heat generated by the operation of air compressor is recycled and recycled.The hot exhaust gas recovery circulation device includes blower, heat dissipation element, water collecting tank and exhaust pipe.The blower is located in the rear end of the heat dissipation fin of mobile air conditioner, and the hot exhaust gas generated by the air compressor is discharged to the heat dissipation unit of water collecting tank, and the heat dissipation pipeline and filter cotton piece inhale lower temperature fresh air and cool down, and then transported to air outlet of air conditioner through exhaust pipe, increase the air output of the mobile air conditioner.The utility model reduces to normal temperature and purifies by blower sending hot exhaust gas of mobile air conditioner to heat dissipation element, and then transported to air outlet of air conditioner to enhance air volume, solve the emission and pollution problem of traditional mobile air conditioner hot exhaust gas.

The application relates to a blade, an impeller and a ventilation device, the blade comprises a plurality of control surfaces arranged in layers along the height direction of the blade, the blade comprises an arc-shaped leading edge, the distance between the leading edge and the central axis of the impeller is an inner diameter of the blade, and the inner diameters of the plurality of control surfaces are different from each other. The impeller of the application changes the design of the blade along the height direction of the blade under the same hub groove structure, so that the leading edge of the blade is designed by using different control points, and the shape of the groove for accommodating the motor of the hub is matched, the air volume is increased, the aerodynamic noise is reduced, the power consumption is reduced, and the aerodynamic performance of the ventilation device is improved.

This utility model relates to the field of mine ventilation equipment technology, specifically to an improved adjustable filter window for mine ventilation safety. It includes a duct body and an adjustment connection unit. The adjustment connection unit includes multiple fan blades, multiple connecting shafts, multiple connecting plates, a movable frame, a track plate, a drive component, a filter assembly, and an installation assembly. In use, the duct body is inserted into the mine's air intake pipe and fixed using the installation assembly. To increase the airflow of the duct body, the drive component is activated, causing the movable frame to move backward within the track plate. During this process, the movable frame, in conjunction with the strip groove, pulls the connecting plate to rotate, causing the fan blades below the connecting shaft to open, increasing the airflow intake area. To reduce the airflow of the duct body, simply move the movable frame in the opposite direction, closing the fan blades and reducing the airflow intake area. This method allows workers to flexibly adjust the ventilation volume according to actual ventilation needs, effectively improving ease of use.

The utility model provides a range hood which comprises a fan, an exhaust fume collecting hood with a bottom inlet and a fan frame, the fan is fixed on the fan frame and communicated with the bottom inlet, the forward side of the fan frame comprises a front cover plate, a ventilation opening is arranged on the front cover plate, an air inlet of the fan is positioned on the forward side, and the air inlet of the fan is communicated with the ventilation opening. The inner side of the front cover plate is connected with an adsorption module used for adsorbing volatile organic compounds, an adsorption inlet of the adsorption module is exposed out of the ventilation opening, the height of the adsorption module is larger than that of the center line of the air inlet, and a closed inner space is formed in the fan frame to communicate with the bottom inlet and an adsorption outlet of the adsorption module. According to the utility model, on one hand, pollutants are adsorbed, so that air flow purification is realized, treatment of pollutants such as VOCs in a kitchen is realized, and the problems of peculiar smell in the kitchen and the like are solved; and on the other hand, the negative pressure of a local area is improved, the problem that the flow speed of the whole area of the air inlet of the fan is uneven due to size reduction of the fan frame is solved, air volume is increased, and rotating speed and noise are reduced.

The invention discloses an automatic air supplement device for a tobacco redrying machine and tobacco redrying equipment, and relates to the technical field of tobacco processing. The automatic air supplement device comprises a flow guide cover, a shutter type air supplement device, a shutter driving device and a lower computer. An air supplementing opening is formed in the flow guide cover, the air supplementing opening is formed in the position close to an atomizing nozzle of a moisture regaining area of the tobacco redrying machine, and the size of the air supplementing opening is determined by the needed air supplementing amount and the minimum air speed of the air supplementing opening; the shutter type air supplementing device comprises a plurality of shutter blades and a linkage mechanism, the shutter blades are connected with the shutter driving device through the linkage mechanism, and the shutter driving device is used for driving the linkage mechanism to drive the shutter blades to rotate, so that the opening degree of the air supplementing opening is adjusted; and the lower computer is used for controlling the action of the shutter driving device. The problems that in the existing tobacco leaf redrying process, air supplement in a moisture regaining area is insufficient, and the air supplement amount is not easy to control can be solved, and therefore the tobacco leaf moisture regaining performance is improved.

The utility model discloses an air volume adjusting device of a constant-displacement air conditioner, which relates to the technical field of air volume adjustment of air conditioners, and comprises a constant-displacement air inlet air conditioner, one end of the air inlet air conditioner is communicated with an air flow meter through a pipeline, and the other end of the air inlet air conditioner is communicated with a precision filter through a pipeline, adjustable electric valves are mounted on a pipeline between the air inlet air conditioner and the air flow meter and a pipeline between the air inlet air conditioner and the precision filter, and the other ends of the adjustable electric valves between the air inlet air conditioner and the air flow meter are connected with an air pump through pipelines; according to the utility model, a part of air is pumped out from the rear part of the system through the air pump and is injected into the pipeline between the air inlet air conditioner and the air flow meter, so that the purpose of increasing the air volume is achieved under the condition that the displacement of the air inlet air conditioner is not changed, and the air flow in the brake emission measuring instrument is controlled through the opening degree of the two adjustable electric valves.

The present invention relates to the technical field of heat dissipation of mobile terminals, and discloses a laptop computer and a heat dissipation structure thereof, wherein the heat dissipation structure comprises a heat dissipation fan, a fan housing of which is provided with a plurality of driving members, driving ends of the plurality of driving members being commonly connected to a protective leakage cover, the protective leakage cover being provided with a plurality of air inlet through holes, the protective leakage cover being fixedly connected to a central through hole of an elastic ring, and the plurality of driving members being used for driving the protective leakage cover to move in a direction away from the heat dissipation fan to reduce the air inlet pressure of the heat dissipation fan; the present invention enables the protective leakage cover connected to the elastic ring through the driving member to move in the thickness direction of the laptop computer, so that the protective leakage cover is away from the heat dissipation fan, and the air inlet pressure of the heat dissipation fan is reduced by increasing the gap on the air inlet side of the heat dissipation fan, thereby increasing the air volume entering into the main casing of the laptop computer, thereby achieving a more efficient heat dissipation effect.

The utility model provides a kind of O type reinforcing rib vane disc cross-flow fan blade, including two groups of vane disc, the middle part of two groups of vane disc is evenly distributed with several groups of fan blade at equal intervals, two groups of vane disc and several groups of fan blade form cross-flow fan blade, the surface of vane disc is provided with reinforcing rib structure;Reinforcing rib structure on the surface of vane disc is evenly transmitted to vane disc by annular continuous structure, significantly reduce the stress concentration of vane disc, thereby reduce the probability of vane disc fatigue cracking, improve the service life of device.

The utility model relates to the technical field of heaters, in particular to a heater fan with a combustion monitoring function. A motor is arranged on the fixing plate, a first wind wheel shell and a second wind wheel shell are arranged on the two sides of the motor respectively, a heating wind wheel is rotationally installed in the first wind wheel shell, a combustion wind wheel is rotationally installed in the second wind wheel shell, a rotating shaft of the motor is connected to the combustion wind wheel and the heating wind wheel respectively, and an air inlet is connected to the front side of the second wind wheel shell. An air outlet is formed in the rear side of the second wind wheel shell, and a wind pressure detection assembly is arranged on the second wind wheel shell; according to the device, a combustion channel is monitored through double-point air pressure, the combustion efficiency and blockage can be monitored in real time, the blockage position can be rapidly positioned through the air pressure value when blockage occurs, and equipment is protected after shutdown; the device simultaneously drives the heating wind wheel and the combustion wind wheel to operate through a single motor, the air volume is large, and the production cost is low; the shell components of the device are formed at one time, the production and assembly processes are simple, and the efficiency is high.

The invention provides a ceiling fan and a fan lamp, and belongs to the technical field of household appliances. The ceiling fan comprises a shell, a fan assembly and a plurality of shielding tongues. An annular opening is formed in the bottom of the shell. The fan assembly is located in the shell, and the multiple shielding tongues surround the fan assembly and divide the annular opening into multiple air outlets. The shielding tongue is provided with a first air guide face, and the first air guide face faces the fan assembly. In the rotating direction of the fan assembly, the first air guide face sequentially comprises a first air guide part and a second air guide part. The second air guide part is in an arc shape, and the convex face of the second air guide part faces the fan assembly. Therefore, on one hand, the shielding tongue partially shields the annular opening, so that the air outlet volume of each air outlet is increased. And on the other hand, the first air guide face of the shielding tongue can guide air to the air outlet, the second air guide portion can enable the air outlet direction of the air outlet to be more deviated to the radial direction of the ceiling fan, and therefore the air supply distance of the ceiling fan is long.

The utility model relates to a ventilation sealing device for improving seat comfort, which comprises an air bag and an air blower communicated with the air bag, the air bag comprises an air bag body and a PP sealing bag, the PP sealing bag covers the outer side of the air bag body or the air bag body covers the outer side of the PP sealing bag, one end of the air bag body is provided with an air inlet, and the other end of the air bag body is provided with an air outlet. An air inlet is formed in the air bag body, a first sealing sleeve pipe is connected to the air inlet, a U-shaped air guide pipe is connected to the first sealing sleeve pipe, the U-shaped air guide pipe is connected with an air outlet connector of an air blower, a plurality of air outlet holes are formed in the side, facing a seat cushion, of the air bag body, and through holes matched with the air outlet holes in position and number are formed in the PP sealing bag. According to the automobile seat, the ventilation performance and the refrigeration effect of the automobile seat can be improved, so that the comfort requirements of drivers and passengers are better met.

The invention relates to a centrifugal impeller and a ventilation device using the same. The centrifugal impeller comprises a central part, a connecting part and a plurality of blades surrounding the central part, wherein the connecting part extends outwards from the central part and is connected to the blades; the blade is bent from the radial inner side to the radial outer side, and a first included angle (alpha) formed by a first tangent line (L1) of the windward side of the blade on the radial outer side and a second tangent line (L2) of the windward side of the blade on the radial inner side is not smaller than 140 degrees and smaller than 180 degrees. Compared with a traditional straight blade scheme, the backward bent blade has larger air volume and higher efficiency, and the centrifugal impeller and the ventilation device can have better air inlet volume and efficiency.

The application relates to the technical field of starting motors, and particularly discloses a fan heat dissipation type starting motor for a centrifugal pump, which comprises a base and a machine shell fixedly connected to the base, a strip-shaped air inlet is arranged on the machine shell and penetrates through the inside and outside of the machine shell, a filter screen for shielding dust is arranged in the strip-shaped air inlet, a rotor is arranged in the machine shell, and a transmission shaft penetrates through the rotor coaxially. At the beginning of starting, the fan blade cannot rotate at high speed, so that the starting response slow degree and the starting current size of the centrifugal pump can be reduced, the additional energy consumption loss of the motor at the initial stage of starting can be reduced, the windward area of the fan blade at the initial stage of starting of the starting motor is small, so that the rotating resistance of the fan blade can be reduced, the starting response slow degree and the starting current size of the centrifugal pump can be further reduced, and the additional energy consumption loss of the motor at the initial stage of starting can be further reduced.

The invention discloses a working face dust removal, spraying and fresh air system for a coal mine, and belongs to the technical field of coal mine underground environment governance and occupational health safety. The system comprises a track hoisting and moving device, a wet-type vortex dust removal fan, a spraying and dust falling device, a fresh air device and an automatic control system. The structural frame is hung on the moving trolley through the hanging chain and is driven by the driving main machine to move dynamically along the track. The dust removal fan adopts the combination of a radial mixing type impeller and a dewatering vortex wheel, so that powerful dust collection and dry and comfortable exhaust are realized; the spraying device realizes intelligent avoiding and spraying stopping through a personnel proximity sensor; the fresh air device is of a double-channel structure, and positive-pressure clean fresh air is provided for the breathing area through four-stage deep purification. The problems that traditional equipment is installed and fixed, functions are split, people are prone to getting wet, and breathing guarantee is lacked are solved, integrated cooperation of full-working-face dynamic cruise control, precise dust suppression and medical-grade fresh air supply is achieved, and the safety and comfort of underground operation are remarkably improved.

The invention discloses a high-voltage electronic fan which comprises an axial magnetic flux motor assembly, a motor controller assembly and a heat dissipation assembly. The axial magnetic flux motor assembly comprises a controller top cover, a controller shell is arranged on the lower portion of the controller top cover, a stator coil installation sleeve is arranged on the lower portion of the controller shell, a stator coil is arranged in the stator coil installation sleeve, a layer of heat conduction insulation sealant is arranged outside the stator coil, and a shaft is arranged at the concentric shaft position of the stator coil installation sleeve and the controller shell. A connecting column is arranged on the shaft; the motor controller assembly is arranged in the axial flux motor assembly and comprises a controller, the controller is arranged in a controller shell, and the connecting column is associated with the controller; the heat dissipation assembly is arranged at the lower part of the axial magnetic flux motor assembly and comprises a fan cover, the fan cover is arranged at the lower part of the stator coil mounting sleeve, fan blades are arranged in the fan cover, a rotor is arranged at the central position of the fan blades, and a bearing is arranged at the central hole position of the rotor; the lower portion of the shaft penetrates through the bearing. The LED lamp has the advantages of light structure, high power, high heat dissipation performance and the like.

The air conditioner indoor unit comprises a machine shell, a first air outlet duct and a second air outlet duct are arranged in the machine shell, the first air outlet duct is provided with a first air outlet, and the second air outlet duct is provided with a second air outlet; the first air guide piece is movably arranged on the machine shell so as to open or close the first air outlet; the second air guide piece is movably arranged on the machine shell so as to open or close the second air outlet; the third air guide piece is movably arranged in the machine shell so as to guide air to flow to the first air outlet channel and / or the second air outlet channel. According to the air conditioner indoor unit, the first air outlet and / or the second air outlet can be selected for air outlet, the air outlet modes of the air conditioner indoor unit are increased, and the air outlet amount of the air conditioner indoor unit can be increased through simultaneous air outlet of the first air outlet and the second air outlet.

The utility model discloses an air conditioner, and relates to the technical field of air conditioners. The air conditioner comprises a shell, an air outlet assembly, a heat exchanger, a purification assembly, a first opening and closing part and a second opening and closing part, a first air inlet is formed in a panel of the shell, a second air inlet is formed in a face frame, when air needs to be purified, the first opening and closing part opens the first air inlet, the second opening and closing part closes the second air inlet, and airflow enters from the first air inlet; the air enters the air outlet assembly after sequentially passing through the purification assembly and the heat exchanger and finally is discharged from the air outlet, air can be purified, and the temperature can be adjusted. When air purification is not needed, the second opening and closing part opens the second air inlet, airflow enters from the second air inlet, passes through the heat exchanger and then enters the air outlet assembly, and finally air is discharged from the air outlet. The air flow does not pass through the purification assembly, so that the air volume loss is reduced, the air outlet volume is large, the indoor temperature can be adjusted more quickly, and the air conditioning efficiency is improved.

The invention discloses a multi-blade fan which comprises a machine frame, a motor is arranged on the machine frame, the motor is provided with an output shaft capable of rotating, the output shaft is connected with a first blade, and the output shaft is further connected with a second blade capable of rotating relative to the output shaft. A clutch structure used for connecting or disconnecting power transmission between the second fan blade and the output shaft is arranged between the second fan blade and the output shaft, the multi-fan-blade fan is simple in structure and capable of achieving hierarchical control, the invention further provides a radiator, and the radiator adopts the multi-fan-blade fan to achieve the purpose of improving the radiating efficiency. The invention further provides a control system applied to the radiator, and the control system can flexibly adjust strategies according to different working conditions, has good self-adaptive capacity and meets the heat dissipation requirement changes in different use scenes.

This utility model discloses an ice maker, including a housing with a receiving cavity. The receiving cavity contains an ice chamber, a condenser, and a cooling fan. The housing has air inlets and outlets on both sides. An air guide shroud is also provided inside the receiving cavity, covering the ice chamber to form a heat dissipation channel between the shroud and the outer wall of the ice chamber. The two ends of the heat dissipation channel are connected to the air inlets and outlets, respectively. The condenser is located at the outlet end of the heat dissipation channel. This utility model, by covering the ice chamber with an air guide shroud to form a heat dissipation channel between the shroud and the ice chamber, increases the airflow velocity as it flows through the heat dissipation channel towards the outlet. By placing the condenser at the outlet end of the heat dissipation channel, the airflow exiting the channel passes through the condenser, thereby increasing the airflow through the condenser and rapidly cooling it, thus enhancing the heat dissipation effect.

The utility model provides a kind of wall-mounted air conditioner indoor unit and air conditioner, it is related to air conditioner technical field to solve the problem of small air output of wall-mounted air conditioner indoor unit zero wind mode. Wall-mounted air conditioner indoor unit includes mainframe shell, air outlet cavity and air outlet opening and closing module, and heat exchange cavity is formed in mainframe shell;Air outlet cavity is formed in air outlet cavity body, and heat exchange cavity is communicated air outlet cavity by inner air outlet port, and the wallboard of air outlet cavity body opposite to inner air outlet port is air diffusion board, and air diffusion board is equipped with air diffusion hole along the direction of plate thickness, and air diffusion board is equipped with outer air outlet port;Air outlet opening and closing module includes air deflector cover plate for opening and closing outer air outlet port, and air deflector cover plate is movably arranged opposite to air diffusion board. It can increase the air output under zero wind mode.

The application provides a cross-flow fan and an electronic device. The cross-flow fan comprises a housing mechanism, a driving mechanism and a fan blade. The housing mechanism is provided with a receiving cavity, an air inlet and an air outlet. The air inlet and the air outlet are arranged on the side surface of the housing mechanism and are in communication with the receiving cavity. The driving mechanism is installed in the receiving cavity. The driving mechanism comprises a rotor and a stator. The rotor is installed on one side of the stator and can rotate relative to the stator under the driving of the stator along the thickness direction of the cross-flow fan. The fan blade is installed in the receiving cavity and is arranged on the rotor and located on the side of the rotor away from the stator. The cross-flow fan can form a higher air volume, which is beneficial to improving the heat dissipation effect of the heating device in the electronic device.

The utility model discloses a material suction machine for an automatic raw material conveying system, which comprises a seat frame, an air suction pipe and an air inlet pipe are integrally arranged on the edges of two sides of the seat frame, an air inlet flange interface is arranged on the side wall of the air suction pipe, and the air inlet flange interface can be connected with an external vacuum hopper; an air suction flange interface is formed in the side wall of the air suction pipe; the negative pressure fan is fixed on the seat frame, and an air inlet of the negative pressure fan is connected with the air suction flange interface through a pipeline; the dust filter is fixedly communicated with the tops of the air suction pipe and the air inlet pipe, the top of the dust filter is connected with an air stop valve, a tray is fixed below the dust filter, a hopper is placed on the tray, and the hopper is located at the bottom of the dust filter and collects dust particles and impurities falling off from the dust filter; and the electric control box is fixed on one side of the dust filter and is electrically connected with the negative pressure fan and the cut-off valve. The dust removal device is simple in structure, stable and reliable to use and free of daily maintenance.

The efficient air duct comprises a shell, a fan assembly and a heating device, the shell comprises an air duct part, a handheld part and an air inlet part connected between the air duct part and the handheld part, and the air duct part is provided with an air outlet and an air outlet duct communicated with the air outlet. The air outlet is located in the end, away from the air inlet part, of the air duct part, and the two opposite sides of the air inlet part are each provided with a first air inlet communicating with the air outlet duct. The fan assembly is arranged in the air outlet duct; the heating device comprises a silicon carbide heating body, the silicon carbide heating body is arranged in the air outlet duct, and a heat exchange surface is formed on the surface of the silicon carbide heating body so as to exchange heat with airflow flowing through the air outlet duct. According to the technical scheme, the structure of the heating device can be simplified, and the air outlet effect is improved.

The utility model relates to the technical field of cooling fans, in particular to a double-layer fan blade structure and a cooling fan, the double-layer fan blade structure comprises an inner ring part, a first fan blade part, an inner space ring and a second fan blade part, the first fan blade part is provided with a plurality of first blades, and the second fan blade part is provided with a plurality of second blades. The inner side edges of the first blades are arranged on the outer periphery of the inner ring part, and the outer side edges of the first blades are connected with the inner periphery of the inner space ring; and the inner side edge of the second blade is arranged on the periphery of the inner space ring. Through the synergistic effect of the double-layer fan blades, the air exhaust efficiency and the air supply effect of the fan can be effectively improved, the balance of the double-layer fan blade structure is better, and the operation of the fan is more stable.