108 results about "Reverse airflow" patented technology

The invention relates to the technical field of air conditioners, and provides a cleaning method and device for an air conditioner indoor unit. Judging whether the dust accumulation parameter reaches a preset cleaning condition or not; under the condition that the dust accumulation parameter reaches the preset cleaning condition, the indoor fan is controlled to operate reversely, so that first reverse airflow flowing from the air outlet to the air inlet is generated and used for purging the filter screen; and the air inlet is controlled to be closed, the indoor fan is controlled again to operate reversely to generate second reverse airflow, and the second reverse airflow is used for discharging the dust falling into the heat exchanger through the condensate water pipeline. Whether the filter screen meets the preset cleaning condition or not is judged by monitoring the dust accumulation parameters of the filter screen in real time, when the preset cleaning condition is met, reverse blowing is conducted on the filter screen, then the air inlet is closed, and dust deposited on the heat exchanger is discharged outdoors through the condensate water pipeline by means of the indoor fan again. Therefore, on-demand cleaning based on the actual dust accumulation condition is achieved, and the cleaning efficiency is improved.

The invention belongs to the technical field of powder metallurgy, and particularly discloses a centrifugal atomization powder making device and method based on controllable airflow regulation, and the device comprises an atomization cabin, a vacuum control system, a bar driving unit, a plasma gun, a reverse airflow generation assembly, an inert gas supply system and a powder collector. The reverse airflow generation assembly comprises a plurality of nozzles which are uniformly distributed along the circumference of the bulkhead; according to the powder preparation method, molten metal atomization is achieved through electrode bar installation, vacuumizing and inert gas filling, electrode bar plasma melting and bar rotating propelling and reverse airflow jetting. Through the synergistic effect of'centrifugal force + controllable reverse airflow ', the diameter of the atomization cabin is reduced to be less than 2 m, the proportion of special-shaped powder is reduced to be less than 3%, the liquid drop cooling rate is increased by 1.5-2 times, high purity of powder, equipment miniaturization and process greenness are considered, the problems of low cooling efficiency, poor powder quality and the like of traditional centrifugal atomization are solved, and the method is suitable for industrial production. The method is suitable for preparing active metal high-end powder such as titanium alloy.

The invention relates to the technical field of fiber fusion, and discloses a textile fiber cotton continuous forming device which comprises a forming machine, a cotton plate forming mechanism is arranged in the forming machine, and the cotton plate forming mechanism comprises a forming die, a pre-forming assembly and a glue solution blowing-floating curing assembly, and the pre-forming assembly and the glue solution blowing-floating curing assembly are matched with each other; a forming discharging port is formed in the forming die, a discharging conveying belt is arranged at the forming discharging port, the pre-forming assembly is composed of a feeding pretreatment channel and a forming continuous cylinder, and the discharging end of the feeding pretreatment channel communicates with the forming continuous cylinder and is flatly laid on the surface of the discharging conveying belt; and the glue solution blowing, floating and curing assembly comprises an air heater and glue blowing strips which are transversely and uniformly arranged along the discharging conveying belt. Through precise cooperation of the hot-air blower and the transverse glue blowing strip, double optimization of glue solution solidification and permeation is achieved, hot air jet from bottom to top forms a reverse airflow field, the falling glue solution generates a suspension permeation effect before solidification, the permeation depth of the glue solution is increased, and the bonding strength of fiber nodes is improved.

The invention discloses a compressed air energy storage multi-stage expansion machine quick starting system and method. The compressed air energy storage multi-stage expansion machine quick starting system comprises multi-stage expansion machines which are sequentially connected in series and a main air inlet pipeline connected to the first-stage expansion machine. The main air inlet module is used for supplying and adjusting air flow to the multi-stage expansion machine in a normal operation mode; the last-stage priority starting module is used for converting a high-pressure gas source into low-pressure large-flow mixed gas flow suitable for being driven by the expansion machine in the initial starting stage, and the converted mixed gas flow bypasses the previous expansion machine and directly drives the last-stage expansion machine to rotate and accelerate; the multi-stage preheating module is used for guiding part of gas to carry out reverse-sequence preheating on the previous-stage expansion machines, reverse airflow serves as starting damping and is further used for assisting in stabilizing the rotating speed, the gas completing the preheating task is exhausted through an exhaust valve, speed increasing and reverse-sequence preheating are carried out in parallel, the starting time is greatly shortened, and the starting efficiency is improved. And the starting time of the unit from the cold state to the grid-connected condition is reduced to the minute level.

The utility model relates to the technical field of gas detection, in particular to a pulverized coal bunker CO gas analysis device which comprises a sampling probe (1), a cleaning structure is arranged on the sampling probe (1); the sampling probe (1) is connected with a detection module; the cleaning structure is used for removing smoke dust, impurities and condensates attached to the surface of the probe and components in the probe by applying reverse airflow into the sampling probe, so that the measurement accuracy is kept, the service life of equipment is prolonged, the maintenance workload is reduced, the sampling flow stability is ensured, and the system reliability is enhanced; the detection module can be used for removing water and possibly residual small particles in the sampled flue gas as well as tiny liquid drops or condensates possibly generated in the dehumidification process; the accurate detection of the CO gas concentration by the device can be effectively realized.

The utility model relates to the technical field of bag-type dust removers, in particular to a bag-type dust remover which comprises a shell, the top end of the shell is communicated with an exhaust port, a compartment rotation switching mechanism comprises six filtering chambers distributed in a honeycomb shape, and an air inlet pipe is fixedly connected to the lower portion of the outer wall of the shell. The control system controls and starts the corresponding pulse blowing pipes to blow downwards to form reverse airflow and strip a dust layer on the surface of the filter bag, the vibration motor drives the whole filter chamber to shake and shake off deep accumulated dust, the dust cleaning effect is good, the shaken-off dust is collected through the dust hopper, finally, the dust is discharged from the dust discharging pipe by opening the dust discharging valve, the pneumatic fluidization rod is started, the airflow enables the dust to be fluidized, and the dust cleaning effect is good. According to the invention, hardening and bridging are prevented, blockage of the ash hopper is avoided, manual knocking intervention is not needed, the safety is high, different filter chambers can be switched to enter a filter mode, and the other filter chambers sequentially enter an ash removal state, so that the device can work continuously without shutdown, and the working efficiency is improved.

The utility model discloses an electronic atomization device. Belongs to the technical field of aerosol generation. In the application, the reverse airflow path is formed among the first enclosure part, the second enclosure part and the first cavity, and the detection surface of the airflow sensor directly faces the enclosure space, so that the airflow sensor can be driven to rotate during suction; the airflow triggering the airflow sensor to generate a feedback detection signal changes the flow direction from the enclosure space to the space between the first enclosure part and the second enclosure part through the second opening, then changes the flow direction to the space between the first enclosure part and the inner wall of the first cavity, enters the second sub-detection air channel, and finally flows out through the first sub-detection air channel. Condensate formed by the aerosol entering the first sub-detection air passage and the second sub-detection air passage is gathered in a space between the second enclosure part and the first cavity under the blocking and guiding of the first sub-enclosure part, so that the condensate is prevented from entering the enclosure space to influence the normal use of the airflow sensor. And the detection air passage is prevented from being blocked by the condensate.

The present application relates to the technical field of stamping die, and discloses a non-woven fabric reinforced plastic pad stamping die, which comprises an upper die unit, a lower die unit and a blockage prevention system; the lower die unit comprises a lower die main body, the lower die main body is sequentially provided with a punching station and a blanking station along the feeding direction of the material belt, and the lower die main body is provided with a blanking channel which is in communication with the lower part of the punching station and the blanking station respectively; the blockage prevention system comprises a blowing execution module which is correspondingly arranged in the blanking channel, a gas supply module which is used for providing a gas source for the blowing execution module and a control module. The blockage prevention system is provided, the blowing unit and the posture sensing unit which are arranged in a high-low staggered manner work cooperatively, the accurate positioning and directional blowing of the jammed material are realized, only the downward thrust is applied from the upper part of the material, the reverse airflow is completely avoided, the success rate of breaking the jam is high, and long-time continuous unmanned production can be realized.

The utility model relates to an endoscope, a gas-water valve and a countercurrent assembly. The countercurrent assembly comprises an anti-countercurrent piece, the anti-countercurrent piece comprises a fixing part and an elastic deformation part arranged on the peripheral side of the fixing part, the fixing part is used for being matched with a connecting part in an air outlet channel of the air-water valve, and the diameter of the elastic deformation part is sequentially increased in the flowing direction of forward airflow of the air outlet channel till the elastic deformation part abuts against the inner wall of the air outlet channel. When the air outlet channel has positive airflow, the positive airflow extrudes the periphery of the elastic deformation part, and the periphery shrinks inwards, so that the positive airflow passes through the space between the elastic deformation part and the inner wall of the air outlet channel; when the air outlet channel has reverse airflow, the reverse airflow extrudes the periphery of the elastic deformation part, and the periphery expands outwards to prevent the reverse airflow from passing through. On the basis of ensuring normal circulation of airflow in the positive direction, the gas cylinder can be prevented from being polluted.

The invention relates to the related technical field of health information monitoring, and discloses integrated health information monitoring equipment and a use method thereof, the equipment comprises a monitor body, and the monitor body is internally provided with an air inlet end, a processing assembly, a condenser, a sensor, a fan and an air outlet end in sequence. The treatment assembly comprises a shell, a cavity unit capable of rotating in the circumferential direction is arranged in the shell, a baffling channel is formed in the cavity unit, and a filtering assembly with a filtering state and a cleaning state is arranged on the baffling channel. The filtering assembly comprises a first arc-shaped filtering plate forming a rough filtering unit and a second arc-shaped filtering plate forming a fine filtering unit. The cavity unit is driven by the driving assembly to rotate, so that the filtering assembly is switched between the filtering station and the cleaning station; the filter resistance change is detected through the differential pressure detector, and when the filter assembly is located at the cleaning station, the cleaning assembly applies reverse airflow to the filter assembly for cleaning.

A bracket is arranged in the middle of the interior of a cabinet body, the interior of the cabinet body is divided into a horizontal cavity and a vertical cavity through the bracket, a first vertical plate, a second vertical plate and a transverse plate are arranged in the horizontal cavity, and a ventilation channel is formed in the side, away from the second vertical plate, of the bracket in a penetrating mode in the vertical direction; the cabinet body is provided with a main supporting plate located in the vertical cavity, the cabinet body is provided with an evaporator located at the bottom end in the horizontal cavity and located below the transverse plate, the two sides of the evaporator are each provided with two sets of fans through fan bases, the two sets of fans are staggered, one set of fans faces the second vertical plate, and the other set of fans faces the second vertical plate. According to the utility model, the structure is reasonable, the two groups of fans are arranged in a staggered manner and do not influence each other, the stability of energy consumption improvement caused by reverse blowing is greatly reduced, and the two groups of fans respectively blow to the horizontal cavity and the vertical cavity, so that the energy consumption rate is reduced.

The invention discloses a vehicle air conditioner defrosting control method, electronic equipment and a computer readable storage medium, and belongs to the technical field of vehicle air conditioner control. According to the defrosting control method, when a vehicle air conditioner is in a heating mode, the heating efficiency is guaranteed through a forward airflow path of an outdoor fan and an outdoor heat exchange unit; defrosting triggering conditions are accurately judged on the basis of air conditioner operation parameters and environment parameters, an outdoor fan reverse airflow mode is adopted in the last stage of a defrosting mode, residual defrosting water drops of an outdoor heat exchange unit are removed in a reverse blowing mode, secondary frosting is prevented, it is ensured that defrosting is thorough, and excessive energy consumption is avoided.

The embodiment of the utility model provides a single-tower VPSA (Vacuum Pressure Swing Adsorption) oxygen generation device adopting a positive and negative pressure all-in-one machine, which comprises an oxygen generation tower body used for loading a filler and performing pressure swing adsorption operation, a filter arranged at a gas inlet of the oxygen generation tower body to filter impurities in gas entering the oxygen generation tower body, and a positive and negative pressure all-in-one machine, wherein the filter is provided with a rotatable flushing rod and a back flushing gas channel, reverse airflow generated in a positive pressure state is used for instantly flushing a filtering layer, a filtering material layer is arranged in the filter to intercept particles, a slag discharging pipe is arranged at the position, located at the lowest end of the filtering material layer, of the filter, and the slag discharging pipe is used for discharging slag. The slag discharge pipe is also provided with a control valve for controlling the on-off of the slag discharge pipe; the positive and negative pressure all-in-one machine is used for alternately applying vacuum extraction and pressurized filling; and the positive and negative pressure all-in-one machine is connected with the oxygen production tower body through a special connecting pipe. Through the scheme of the embodiment of the invention, unsmooth airflow caused by impurity accumulation can be reduced.

The utility model relates to the technical field of plastic processing, in particular to a self-cleaning plastic screw extruder, which comprises a screw extrusion barrel for producing plastic products, a forward and reverse rotation servo motor is mounted at one end of the screw extrusion barrel, and a feed hopper and a self-cleaning reverse blowing machine are mounted at the top of the screw extrusion barrel. According to the utility model, the self-cleaning blowback machine is arranged, and the air outlet connecting air pipe of the self-cleaning blowback machine is in interference insertion fit with the blowback air hole in the top of the screw extrusion barrel, so that during cleaning, the self-cleaning blowback machine can provide reverse airflow to the inside of the screw extrusion barrel, residual plastic on the inner wall of the screw extrusion barrel and a screw is effectively removed, and blockage is avoided; due to the design of the replaceable extrusion head at one end part of the screw extrusion barrel, a user can easily replace extrusion heads with different specifications or functions according to production requirements, and the flexibility and applicability of equipment are improved; in addition, a forward and reverse rotation servo motor is installed, so that the screw rod can work in a reverse rotation mode, and the self-cleaning effect of the equipment is enhanced.

The utility model relates to the technical field of air windows, and discloses a mining air window which comprises a window frame, a rotating door movably connected in the window frame in a sleeved mode, a PLC fixedly installed on one side of the window frame, and a door closing assembly arranged on one side of the window frame and used for closing the rotating door. Through mutual cooperative use of the window frame, the revolving door, the limiting frame, the moving plate, the push-pull electromagnet and the limiting groove, the effect of closing the revolving door is achieved, when reverse airflow (such as gas outburst shock waves) occurs, the revolving door can be quickly pushed to be closed through external force, the situation that the revolving door is difficult to respond quickly due to blockage and the like is avoided, and the service life of the revolving door is prolonged. Meanwhile, under the normal condition, the electromagnetic lock switch is controlled by collecting the air pressure difference between the windward side and the leeward side, a user does not need to manually open the rotating door, ventilation is conducted in time, use is convenient, and practicability is achieved.

This invention relates to the field of automated packaging and surface coating equipment, specifically to an integrated processing device and method for uniform spraying and curing of cosmetic bottle surfaces. It comprises core components such as a multi-axis robotic arm, a coaxial annular atomizing nozzle, a Coanda effect flow guide, a high-frequency ultrasonic transducer, and ultraviolet light-emitting diodes. The device utilizes the atomizing nozzle to generate a pneumatic vector field to transport the coating material, and uses the Coanda effect flow guide to change the direction of the rebounding airflow, forming a centripetal constraint on the main jet. Its core is the high integration of spraying, ultrasonic, and ultraviolet curing components into a single actuator head, enabling wet film spreading and curing to be completed collaboratively in adjacent spaces. This invention effectively reduces the disturbance of the uncured wet film by the reverse airflow, improves the deposition stability at complex contours, and avoids spatial position deviations caused by traditional segmented processing and separate transport.

The present invention provides a portable ventilator suitable for cardiopulmonary resuscitation (CPR) and a control method thereof. According to the present invention, the number of external chest compressions in a CPR process can be automatically recognized on the basis of reverse airflow, and a compression period and a relaxation period can be determined. The portable ventilator has an automatic 30:2 ventilation mode suitable for non-intubated patients and a variable-volume ventilation mode suitable for patients with advanced airways. The present invention can improve the efficiency of first aid and avoid barotrauma, is suitable for the first aid during CPR, and can achieve precise flow control.

The invention relates to a central dust removal device for dust-free wooden door plate processing, and belongs to the technical field of reverse airflow dust separation, the central dust removal device comprises a dust discharge pipe and a plurality of ducts, and the ducts are arranged on the inner wall of the dust discharge pipe and used for introducing airflow into the dust discharge pipe; the main path air passage is connected with a plurality of branch path air passages; the hole channel is connected with the cavity; the branch air passage is connected with the cavity and is used for blowing air flow into the cavity; the slide rheostat comprises a slip sheet, the slip sheet slides in the cavity under the action of airflow, and the resistance value of the slide rheostat is changed after the slip sheet moves; the electromagnetic valve is arranged on the branch air channel; the slide rheostat is connected with the electromagnetic valve; the slide rheostat controls on-off of the solenoid valve after resistance changes. The device has the effect of automatically detecting the position of the wall hanging material in the dust exhaust pipe.

The invention provides a powder electrostatic measurement system, and belongs to the technical field of material electrostatic experiments, the powder electrostatic measurement system comprises a system rack, the system rack is provided with a raw material supply module, an airflow driving module, an experiment pipeline module, a flow monitoring module, an electrostatic measurement module and a powder collection module; the raw material supply module comprises a quantitative discharging mechanism and a powder scattering mechanism. The airflow driving module comprises an air compressor and a powder conveying fan; the flow monitoring module comprises a flow meter, an anti-blocking tee joint and a pulse blower device; the pulse blower device is used for regularly outputting reverse airflow to prevent powder from being accumulated and blocked at a sampling port of the flow meter; the electrostatic measurement module comprises a Faraday cup and an electrostatic charge measurement device; the powder collecting module comprises two powder collecting cylinders which are arranged in series; the problem that influences of different pipeline materials and different section shapes on electrostatic characteristics of powder in an actual industrial scene are difficult to simulate can be solved.

The utility model relates to tempering protection device technical field, especially a kind of preheating burner tempering protection device for gasification device, including preheating burner, first guide ring, second guide surface, connecting sleeve, sealing disc, drainage portion, slide bar and limit sleeve, preheating burner is equipped with 90 ° bending structure in its export end, first guide ring is fixedly installed in preheating burner inner wall, and its bottom surface is equipped with first guide surface.The utility model wherein preheating burner is equipped with 90 ° bending structure in its export end, changes the axial ejection direction of traditional straight-through structure, forces flame to flow along bending path, makes high-temperature gas away from operating area, when tempering occurs, flame blocked by fire-retardant net, reverse airflow pushes sealing disc, drives sealing disc to close first guide ring, forms physical block, reduces flame from preheating burner and avoids preheating burner open end directly towards patrol channel and operator work area to cause direct burn threat.

The invention relates to the technical field of flue gas treatment equipment, and provides a dust removal device for a blast furnace flue gas treatment system, which comprises a box body and a filter bag frame arranged in the box body, and further comprises a driving mechanism and a rapping frame, the rapping frame is arranged in the box body, sleeves which are in one-to-one correspondence and sleeve the lower part of the filter bag frame are arranged in the rapping frame, and first sliding rods are symmetrically arranged on two sides of the rapping frame. According to the invention, the defects in the prior art are overcome, the design is reasonable, the structure is compact, a dust layer with relatively strong adhesive force on the surface of the filter bag can be effectively destroyed and stripped through periodic mechanical rapping in a dust cleaning mode of combining mechanical rapping and pulse blowing, and favorable conditions are created for subsequent blowing; the pulse blowing can provide strong instant reverse airflow, go deep into the filter bag and remove loose fine dust after vibration, the pulse blowing and the filter bag act synergistically, the overall dust removal efficiency and thoroughness are remarkably improved, and the device is particularly suitable for the working condition of dust which is complex in component and possibly viscous in blast furnace flue gas.

The invention relates to an air quality sensor. A housing has a flow channel for guiding air to be measured through the housing; at least part of the first sensor is inserted into the flowing channel, the flowing channel comprises a measuring channel and a bypass channel, and the first sensor is configured to be used for detecting forward airflow flowing in from the first opening and flowing out from the second opening and reverse airflow flowing in from the second opening and flowing out from the first opening. According to the scheme, reverse airflow can be detected, the influence of pulsating airflow is reduced, and the measurement precision is improved.

The utility model provides a kind of refrigeration equipment, which comprises: a cabinet;Evaporative bin;Evaporator;Air supply air duct;First fan, first fan is located in air supply air duct, and is located at air inlet;First fan is configured to: first fan can extract air in evaporative bin through air inlet, and is transported to refrigeration chamber through air supply air duct, air outlet;Second fan, second fan is located at air inlet;Second fan is configured to: second fan can extract air in air supply air duct and is transported to evaporative bin through air inlet.According to the refrigeration equipment provided by the utility model, when the refrigeration equipment is in defrosting mode, the reverse airflow formed by the second fan blocks the hot air in the evaporative bin from flowing into the air supply air duct, thereby preventing the hot air from entering the refrigeration chamber through the air supply air duct, and reducing the temperature change in the refrigeration chamber during defrosting, thereby avoiding affecting the refrigeration effect of the refrigeration chamber.

An air intake (1) for an aircraft propulsion assembly (8) is disclosed, which extends along a longitudinal axis (X) and comprises a turbojet engine (7) comprising a primary flow path (4) and a secondary flow path (5) for guiding, respectively, a primary flow (F1) and a secondary flow during thrust, and a thrust reverser device for changing the secondary flow into a reversed flow (F-INV) during thrust reversal (B), the air intake (1) comprising a peripheral casing (11) comprising, in each plane radial to the axis (X), a point of maximum curvature (P) of the reversed flow (F-INV), a osculating circle of the radius of curvature defined at each point of maximum curvature (P), the average value (Rmoy) of the radii of curvature satisfying: Rmoy < 0.028*R3, with R3 being the internal radius of the air intake (1).

The utility model relates to filter cartridge dust collecting technical field, and disclose a kind of high-efficiency filter cartridge dust collecting device, including outer machine component, the bottom end of outer machine component is provided with unloading assembly, the side wall of unloading assembly is provided with air inlet, the inside lower end of outer machine component is penetrated with flow guide cover, filter assembly, the bottom of flow guide cover is set to the top end of unloading assembly, flow guide cover is set to the bottom end of filter assembly, the upper end left side of outer machine component is provided with air outlet. The filter screen of filter assembly is set in double-layer folding page inner layer, greatly increase the filtration area, can more fully intercept dust, improve filtration efficiency and purification effect, in the aspect of dust cleaning, pulse blowing component bottom end surrounds and is inclined on the outside wall of filter assembly top, when spray valve opens, the compressed air that spray pipe sprays can be with high-efficiency angle and direction impact filter cartridge surface, produce instantaneous reverse airflow, make filter cartridge swell shrink deformation.

The application discloses an oil fume extractor, which comprises a fan system and an air outlet cover arranged at an air outlet of the fan system, the fan system comprises a volute and an impeller arranged in the volute, the volute comprises a volute tongue, and the air outlet cover comprises an outlet, and the outlet throat area of the volute is smaller than the area of the outlet of the air outlet cover, wherein the outlet throat area of the volute is the cross-sectional area of the volute passing through the starting end of the volute tongue, and the cross section is parallel to the axis of the impeller. Compared with the prior art, the outlet throat area of the volute is small, the reverse airflow is less, and the noise reduction of the user working condition is facilitated.

The utility model discloses an atomization device which comprises a liquid storage bin, an atomization core and an air outlet assembly, the liquid storage bin is configured to store an atomization matrix, and an atomization channel is formed in the liquid storage bin in a penetrating mode; the atomizing core is arranged in the atomizing channel, and the atomizing core is configured to receive and atomize the atomizing matrix to generate aerosol; the air outlet assembly comprises a one-way valve, the one-way valve is provided with an air inlet end and an air outlet end, the air inlet end communicates with the atomization channel, and the one-way valve is configured to only allow the fluid medium to flow in the direction from the air inlet end to the air outlet end. Through the arrangement of the one-way valve, it can be ensured that the fluid medium can be output in the direction from the air inlet end to the air outlet end, reverse airflow is prevented from entering the atomization channel, and then condensate is prevented from flowing back under the action of the reverse airflow.

The invention discloses an associated gas generator set protection device, a generator set and a using method. The associated gas generator set protection device comprises a gas inlet protection device and a fire retardant protection device which are sequentially communicated; a buoyancy valve is arranged in the air inlet protection device; the fire-retardant protection device comprises a gas-blocking cooling section, a main cooling section and a main gas-blocking section which are connected in sequence; and a reverse circulation gas blocking channel is arranged in the main gas blocking section, so that gas passes through in the forward direction and is blocked in the reverse direction. The functions of opening the air inlet channel and blocking liquid are achieved through the buoyancy valve at the same time, the structure is simple, external power is avoided, and reliability is high. Sparks in reverse airflow can be extinguished, and backfire accidents are prevented.

A portable fume collection system is provided for capturing fumes, dust and gaseous and particulate matter created during welding and other applications. The portable fume collection system includes a downdraft table component and a fume capture arm component. The portable fume collection system includes a frame with an interior housing a motor and a fan for generating reverse airflow at the downdraft table component and the fume capture arm component.

The present application relates to carbon dioxide detection technology field, specifically to a kind of petrochemical combustion carbon dioxide content detection equipment, including non-dispersive infrared gas analyzer, the non-dispersive infrared gas analyzer outside is shell, the non-dispersive infrared gas analyzer is provided with gas inlet, exhaust port, the gas inlet is inserted with sampling tube, one end of the sampling tube is sampling head, the inside of the sampling head is provided with the backflow prevention structure of gas, when potential backflow occurs, reverse airflow attempts to enter from the small mouth end of fairing, at this time, the flow resistance of intercepting groove is substantially increased, due to the existence of intercepting groove, reverse airflow needs to overcome greater resistance to pass through, and the gas of backflow bounces back after impacting the baffle at one end of fairing, realize the blocking when gas backflow, the design of conical fairing also shrinks the passage of backflow gas, further improve the resistance, therefore effectively inhibit the reverse flow of gas to prevent its backflow.