CN103394261B - A kind of single blower fan weldering cigarette absorption cleaning device - Google Patents

Abstract

The invention discloses a single fan welding smoke absorption purifier, which belongs to the technical field of welding smoke treatment. A single-fan welding fume absorption purifier of the present invention includes a smoking mechanism, a welding fume purification mechanism and a welding fume tracking mechanism. The smoking mechanism includes a fan, and the fan absorbs welding fume and transports it to the welding fume purification mechanism; The welding fume purification mechanism described above includes a clean room and a recoil device, the recoil device is located inside the clean room, and the bottom of the recoil device communicates with the clean room, the inside of the clean room is equipped with a purification liquid, and the above-mentioned fan blows the welding fume It is delivered to the cleaning liquid inside the recoiler; the welding fume tracking mechanism acts on the smoking mechanism, and is used to control the smoking mechanism to track and absorb welding fume at a welding speed. The invention can track and absorb welding fumes according to the welding speed and welding directions, greatly improves the efficiency of welding fume absorption and purification, and the suction stroke is increased from 300 mm in the prior art to 380 mm.

Description

A single fan welding fume absorption purifier

technical field

The invention belongs to the technical field of welding fume treatment, and more specifically, the invention relates to a single fan welding fume absorption purifier.

Background technique

In boiler manufacturing industry, heavy machinery, vehicle manufacturing, shipbuilding generator set manufacturing and other fields, there are large welding workshops. In these workshops, there are generally dozens or hundreds of electric welding machines or several large-scale automatic welding equipment. When these welding machines work at the same time, the welding fume content in the workshop is very high, which seriously pollutes the air and endangers welding personnel and workers. The health of those around you. The welding methods that generate welding fume are mainly manual arc welding and gas shielded welding. In manual arc welding, the main components of fumes produced by titanium-calcium type acid electrodes and low hydrogen type basic electrodes are Fe ₃ O ₄ , MnO ₂ , SiO ₂ and Fe ₂ O ₃ , and there are certain other chemical components, such as MgO, CaO, TiO ₂ , Na ₂ O, CaF ₂ , NaF, etc. Harmful gases and substances discharged in gas shielded welding mainly include: NO _X , CO, O ₃ , fluorides and halides, etc. In the field of modern industry, the welding of metal materials is one of the most basic structural parts processing procedures. However, with the rapid development of welding technology, the harm of welding fume to the environment and welders has not yet attracted enough attention. During the welding process, a large amount of welding fume is produced, which pollutes the working environment. In the case of poor ventilation, the concentration of smoke and dust usually exceeds the national standard by several times, which can cause welder pneumoconiosis, manganese poisoning, respiratory inflammation, neurasthenia and other occupations harm.

At present, there are two main methods for collecting and processing welding fume: one is to carry out overall ventilation in the welding operation area of the workpiece to collect and process the smoke. large, high energy consumption, and unsatisfactory smoke removal effect; the other is to use a point-to-point method, that is, to collect and process the welding fume generated by a single welding point with a small exhaust port, which requires a small amount of exhaust air , has the advantages of flexible use, convenience, and energy saving.

At present, most of domestic welding fume purification adopts industrial filter cloth filtration method, wet method and activated carbon adsorption method, and these methods have insurmountable shortcomings. For example, there is a contradiction between the density of the air holes of the industrial filter cloth and the size of the air volume, and the filter needs to be replaced frequently, and the maintenance cost is high; in the wet treatment, when dealing with a large amount of smoke and dust, there are frequent replacement of chemicals and the movement of the chemical tank Contradiction; activated carbon adsorption requires a long activation process. These contradictions are almost insurmountable. In addition, most of the current smoke hoods are fixed, which absorbs very little for the welding fume produced by the moving welding torch, and a large amount of welding fume diffuses into the air, and the existing The suction range of the welding fume absorption and purification device in the technology is generally 300mm, and the suction range is short, which is inconvenient to fully absorb the welding fume. At present, there is a device that fixes the smoke hood on the protective mask used by the welding workers. Although this method solves the problem of moving the smoke hood, the general protective mask is outside the jet area of the welding fume, so it is better to install it on the mask. The smoke hood can not suck all the welding fume into the purifier, and the pipeline is relatively large, so it is extremely inconvenient for workers to operate.

Through patent retrieval, relevant technical schemes have been disclosed about the purification treatment method of welding fume, such as: Chinese patent application number: 201220363674.4, application date: July 25, 2012, and the name of the invention is: Dust removal and purification for wear-resistant parts repair device, the application includes a dust collection box and a water tank, the top of the dust collection box is provided with a suction inlet joint, and the dust collection box is provided with a filter plate that separates the bottom of the dust collection box into a suction drawer room , There are drawers that can be opened in the dust collection drawer room, pipe joints are installed on the upper side wall of the dust collection box, and aluminum platinum hoses are connected to the pipe joints. The filter screen at the connection with the side wall of the vacuum box; the water tank is provided with a smoke outlet joint and a smoke inlet joint connected to an aluminum-platinum hose, a water inlet pipe is installed on the top of the water tank, and a water outlet pipe is installed on the bottom of the water tank. This application can purify the fume generated by surfacing repair, which reduces the environmental pollution of surfacing repair to a certain extent, but its purification efficiency of welding fume is low, and it cannot be tracked according to the welding speed and welding positions. Absorb welding fumes.

Contents of the invention

1. The technical problem to be solved by the invention

The purpose of the present invention is to overcome the disadvantages of the low efficiency of welding fume absorption and purification in the prior art, and provide a single-fan welding fume absorption and purifier, adopting the technical scheme of the present invention, using air flow recoil water to atomize floating balls to filter The method greatly improves the purification efficiency of smoke and dust, and has small resistance and large suction range.

2. Technical solution

In order to achieve the above object, the technical scheme provided by the invention is:

A single-fan welding fume absorption purifier of the present invention includes a smoking mechanism, a welding fume purification mechanism and a welding fume tracking mechanism. The smoking mechanism includes a fan, and the fan absorbs welding fume and transports it to the welding fume purification mechanism; The welding fume purification mechanism described above includes a clean room and a recoil device, the recoil device is located inside the clean room, and the bottom of the recoil device communicates with the clean room, the inside of the clean room is equipped with a purification liquid, and the above-mentioned fan blows the welding fume It is delivered to the cleaning liquid inside the recoiler; the welding fume tracking mechanism acts on the smoking mechanism, and is used to control the smoking mechanism to track and absorb welding fume at a welding speed.

As a further improvement of the present invention, the welding fume purification mechanism also includes a water discharge valve, an air outlet pipe and a filter. The bottom of the clean room is provided with a water discharge valve; The upper opening of the flusher is larger than the lower opening, and steel wool balls and sponge blocks are arranged inside the recoiler; an air outlet pipe (6) is installed on the top of the clean room, and a filter is installed at the upper end of the air outlet pipe.

As a further improvement of the present invention, the smoking mechanism also includes a smoking hood, a smoking hose, a fan inlet pipe and a fan outlet duct, and the smoking hood communicates with the fan inlet pipe through the smoking hose. The fan inlet pipe is in an "L" shape. The fan suction port of the fan is connected to one end of the fan inlet pipe, and the other end of the fan inlet pipe is closed. The fan outlet of the fan is connected to the welding fume purification unit through the fan outlet duct. Inside the recoiler of the mechanism, and the position where the fan outlet duct is inserted into the recoiler is the center of the recoiler.

As a further improvement of the present invention, the welding smoke tracking mechanism includes a lifting tracking assembly and a left and right tracking assembly, wherein: the left and right tracking assembly includes a tracking bracket platform, a first guide rail, a second guide rail and a left and right drive screw rod, The first guide rail, the second guide rail, and the left and right drive screw rods are all fixed on the outer peripheral shell of the fan inlet pipe, and the first guide rail, the second guide rail, and the left and right drive screw rods are all connected to the "L"-shaped fan air intake The central axis of the horizontal section of the pipe is parallel to each other. A circular hole for connecting the smoking hose is opened in the middle of the tracking bracket platform. The bottom of the tracking bracket platform is slidably installed on the first guide rail and the second guide rail. The tracking bracket platform Mesh with the left and right transmission screw rods, the left and right transmission screw rods are driven by the motor, and the motor is connected to the frequency converter; the lifting tracking component includes the extension plate of the lifting bracket, the upper and lower driving handwheels, the lifting screw rod, the sliding sleeve, Smoke hood screw rod, bracket vertical plate, smoke hood extension and fixing pipe and smoke hood bracket, the sliding sleeve is fixedly connected to the tracking bracket platform, and the extension plate of the lifting bracket is slid up and down on the sliding sleeve, and the extension of the lifting bracket The plate is fixedly connected with the lower end of the lifting screw, and the upper end of the lifting screw is equipped with an up and down transmission handwheel, and the up and down transmission handwheel drives the extension plate of the lifting bracket to perform lifting movement through the lifting screw; the extension plate of the lifting bracket A smoke hood screw rod and a vertical bracket vertical plate are installed. The fixed end of the smoke hood screw rod is connected with the smoke hood. The smoke hood bracket is fixedly connected with the smoke hood, and the smoke hood bracket is used for supporting the smoke hood.

As a further improvement of the present invention, the filter includes a first layer of filter net, steel balls and a second layer of filter net, and the steel ball is arranged between the first layer of filter net and the second layer of filter net.

3. Beneficial effect

Compared with the existing known technology, the technical solution provided by the invention has the following remarkable effects:

(1) A single-fan welding fume absorption purifier of the present invention, its smoking mechanism absorbs the welding fume through the fan and transports it to the welding fume purification mechanism. After the welding fume enters the recoil device of the welding fume purification mechanism, the purification liquid mist The atomized purification liquid absorbs the dust in the welding fume, and the welding fume tracking mechanism acts on the smoking mechanism to control the smoking mechanism to track and absorb welding fume at the welding speed, so that the efficiency of welding fume absorption and purification is greatly improved, and Due to the small resistance of the equipment, the suction lift is increased from 300 mm in the prior art to 380 mm;

(2) In the single-fan welding fume absorption purifier of the present invention, the recoil device located inside the clean room has an inverted conical structure. Steel balls and sponge blocks are arranged inside the recoil device, and the air outlet pipe at the top of the clean room A filter is installed on the upper end, so that when the welding fume is injected into the inverted conical recoiler, the purification liquid inside the recoiler is recoiled and stirred by the air flow, and the dust in the welding fume is wetted by the atomized purification liquid. Steel balls and sponge blocks absorb a lot, and because the steel balls and sponge blocks are constantly stirred by the atomized airflow on the purification liquid surface of the recoiler, the smoke and dust adsorbed on the steel balls and sponge blocks are washed into the purification liquid, This cycle of adsorption and cleaning ensures that the steel ball and sponge block can repeatedly absorb smoke and dust, thereby greatly improving the absorption and purification efficiency of welding fume. And the sponge block is not easy to be dirty, so it does not need to be replaced frequently, and the maintenance cost is low;

(3) A single-fan welding fume absorption purifier of the present invention, its welding fume tracking mechanism includes a lifting tracking assembly and a left and right tracking assembly, the lifting tracking assembly can track and absorb welding fume at a welding speed in the vertical direction, and the left and right tracking assembly makes it possible to It can track and absorb welding fume at the welding speed in the horizontal direction, so that the fume hood is always in the jet flow area of welding fume, thus greatly improving the timeliness and comprehensiveness of the fume hood absorbing welding fume;

(4) The single-fan welding fume absorption purifier of the present invention has low maintenance cost, and it can be used normally only by regularly replacing the purification liquid inside the clean room and the filter at the upper end of the air outlet pipe. It is easy to use, light in weight, and low in noise. Low.

Description of drawings

Fig. 1 is the schematic diagram of the main view structure of a kind of single blower welding fume absorption purifier of the present invention;

Fig. 2 is a top view structural schematic diagram of a single fan welding fume absorption purifier of the present invention;

Fig. 3 is a structural schematic diagram of the welding smoke tracking mechanism in the present invention.

Explanation of the labels in the schematic diagram:

1. Clean room; 2. Backwasher; 3. Drain valve; 4. Fan; 5. Fan outlet duct; 6. Air outlet pipe; 7. Filter; 8. Lifting bracket extension plate; 81. Up and down drive handwheel ; 82, lifting screw rod; 83, sliding sleeve; 84, smoke hood screw rod; 85, support vertical plate; 86, smoke hood extension fixed pipe; Guide rail; 92, the second guide rail; 10, the smoking cover; 11, the smoking hose; 12, the fan air inlet pipe.

Detailed ways

In order to further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings and embodiments.

Example 1

With reference to Fig. 1, Fig. 2 and Fig. 3, a single-fan welding fume absorption purifier of this embodiment includes a smoking mechanism, a welding fume purification mechanism and a welding fume tracking mechanism, and the lower part of the housing of the single-fan welding fume absorption purifier is installed There are four universal wheels, which are easy to move, and the cost of use and maintenance is extremely low. The smoking mechanism in this embodiment is used to absorb and transport the welding fume to the welding fume purification mechanism. As shown in Figure 2), the smoking hood 10 communicates with the fan inlet pipe 12 through the smoking hose 11, and the fan inlet pipe 12 is in an "L" shape structure, and the fan suction port of the above-mentioned fan 4 is connected to the fan inlet One end of the air pipe 12 is connected, and the other end of the fan air inlet pipe 12 is closed. The fan outlet of the above-mentioned fan 4 is connected to the inside of the recoiler 2 of the welding fume purification mechanism through the fan outlet air pipe 5, and the fan outlet air pipe The position where 5 is inserted into the interior of the recoiler 2 is the center position of the recoiler 2. The diameter of the smoke hood 10 in this embodiment is 200mm.

As shown in Figure 1, the welding fume purification mechanism in this embodiment is used to purify the welding fumes absorbed by the smoking mechanism. 7. A drain valve 3 is provided at the bottom of the clean room 1 . The recoiler 2 is located inside the clean room 1, and the bottom of the recoiler 2 is connected to the clean room 1. The clean room 1 is equipped with a purification liquid, and the above-mentioned fan 4 transports the welding fumes to the clean room inside the recoiler 2. In the liquid, the recoiler 2 is an inverted cone structure, the upper opening of the recoiler 2 is larger than the lower opening, and the recoiler 2 is provided with steel wool and sponge blocks, specifically in this embodiment: clean room The internal diameter of 1 is 450mm, the height of clean room 1 is 500mm, the upper opening diameter of recoiler 2 is 440mm, the lower opening diameter of recoiler 2 is 180mm, the height of recoiler 2 is 130mm, recoiler 2 There is a groove on the side wall of the lower opening, and the recoiler 2 is directly placed on the bottom of the clean room 1. The structure of the groove is designed so that the inside of the recoiler 2 communicates with the clean room 1. In this embodiment, The purification liquid is water; 0.2kg of steel wool balls and 0.15kg of sponge block are placed inside the recoiler 2, and the size of the sponge block is 50mm×40mm×30mm. Experiments have proved that the above-mentioned structural design is the most effective in purifying welding fume, especially It is the taper of the recoiler 2 and the steel balls and sponge blocks inside it that have the greatest influence on the purification efficiency of welding fumes. The taper of the recoiler 2 in this embodiment can significantly improve the recoil and stirring effect of the airflow. The top of the clean room 1 is equipped with two air outlet pipes 6, which are symmetrical to the center of the clean room 1, and the upper end of the air outlet pipe 6 is equipped with a filter 7, which is not covered by the above-mentioned recoiler 2. The small amount of dust absorbed by the steel wool and the sponge block is filtered and adsorbed by the filter 7 at the upper end of the air outlet pipe 6. The filter 7 includes a first layer of filter screen, a steel wool ball and a second layer of filter screen. The steel wool is arranged on the Between the first layer of filter screen and the second layer of filter screen, the filter 7 of the present embodiment can be called according to its structure: double-net one ball filter, the mesh of its first layer of filter screen and the second layer of filter screen The number is 36 mesh/cm ² , and the weight of the steel wool ball is 0.025 kg.

In order to be able to track and absorb welding fumes according to the welding speed and welding directions, this embodiment designs a welding fume tracking mechanism (as shown in Figure 3). The welding fume tracking mechanism in this embodiment acts on the smoking mechanism. In order to control the smoking mechanism to track and absorb welding fume at a welding speed, the welding smoke tracking mechanism includes a lifting tracking assembly and a left and right tracking assembly, wherein: the left and right tracking assembly includes a tracking bracket platform 9, a first guide rail 91, a second guide rail 92 and The left and right transmission screw rods, the first guide rail 91, the second guide rail 92, and the left and right transmission screw rods are all fixed on the casing of the fan inlet pipe 12 periphery, and the first guide rail 91, the second guide rail 92, the left and right transmission wires The rods are all parallel to the central axis of the horizontal section of the "L"-shaped fan inlet pipe 12, and the middle of the tracking bracket platform 9 is provided with a round hole for connecting the smoking hose 11, and the bottom of the tracking bracket platform 9 is slidingly installed On the first guide rail 91 and the second guide rail 92 , the tracking bracket platform 9 is engaged with the left and right driving screw rods, and the left and right driving screw rods are driven by motors connected to frequency converters. During actual use, the rotating speed of the motor is adjusted by the frequency converter, so that the left and right moving speed of the smoke hood 10 is synchronized with the welding speed, the motor drives the left and right transmission screw rods to rotate, and the left and right transmission screw rods drive the tracking support platform 9 along the first guide rail 91, The second guide rail 92 slides, and the sliding direction is parallel to the central axis of the horizontal section of the "L"-shaped fan air inlet pipe 12. While tracking the left and right movements of the support platform 9, it drives the entire smoking hose 11 and the smoking hood 10 to move left and right, thereby making the smoking The hood 10 is capable of automatically tracking the welding speed.

The lifting tracking assembly in this embodiment includes a lifting bracket extension plate 8, an up and down transmission hand wheel 81, a lifting screw rod 82, a sliding sleeve 83, a fume hood screw rod 84, a bracket vertical plate 85, a fume hood extending and fixing pipe 86 and a fume hood. The cover bracket 87, the sliding sleeve 83 is fixedly connected on the tracking bracket platform 9, the extension plate 8 of the lifting bracket slides up and down and is arranged on the sliding sleeve 83, and the extension plate 8 of the lifting bracket is fixedly connected with the lower end of the lifting screw rod 82 , the upper end of the lifting screw 82 is equipped with an up and down transmission handwheel 81, and the up and down transmission handwheel 81 drives the lifting bracket extension plate 8 to perform lifting movement through the lifting screw rod 82; the lifting bracket extension plate 8 is equipped with smoke Cover screw rod 84 and vertically arranged bracket vertical plate 85, the fixed end of the smoke hood screw rod 84 is connected with the smoke hood 10, and the bracket vertical plate 85 extends the fixed pipe 86 and the smoke hood support 87 through the horizontally arranged smoke hood. The smoke hood bracket 87 is fixedly connected with the smoke hood 10 , and the smoke hood bracket 87 is used to support the smoke hood 10 . In actual use, the upper and lower transmission handwheels 81 can be driven by connecting the motor with the frequency converter, the lifting screw 82 drives the extension plate 8 of the lifting bracket to perform lifting movement, and the extension plate 8 of the bracket drives the vertical plate 85 of the bracket and the extension and fixing pipe 86 of the smoke hood in turn 1. The smoke hood bracket 87 moves to realize the lifting movement of the smoke hood 10; the smoke hood screw rod 84 is used to control the direction of the smoke hood 10. Adopting the welding smoke tracking mechanism of this embodiment can satisfy welding smoke absorption of various welding methods such as fixed-point welding, long flat welding, long vertical welding, circular arc welding, and overhead welding.

The process of absorbing and purifying welding fume by using a single-fan welding fume absorption purifier of this embodiment is as follows, and the specific steps are:

Step 1. Start the fan 4 in the single-fan welding fume absorption purifier, let the single-fan welding fume absorption purifier run dry for 5 minutes, and run dry for a period of time before use. The sponge block is fully atomized and wetted, and on the other hand, the filter 7 at the upper end of the outlet pipe 6 is fully wetted by the atomized water, which can improve the efficiency of welding fume purification;

After step 2 and step 1 are completed, adjust the upper and lower transmission handwheel 81 and the smoke hood screw 84 to make the smoke hood 10 close to the position to be welded. The angle with the welding object should be kept between 45°~50° to maintain a good smoking effect, and by adjusting the frequency converter to control the transmission speed of the left and right driving screw rods, the left and right moving speed of the smoking hood 10 is synchronized with the welding speed;

After step 3 and step 2 are completed, under the action of the pressure generated by the fan 4, the welding fume is absorbed by the smoke hood 10 and the welding fume is sucked into the fan inlet pipe 12, and enters the recoiler 2 through the fan outlet duct 5, wherein, The air volume of fan 4 is 2200m ³ /h;

Step 4, the welding fume entering the recoiler 2 is in contact with the atomized water, steel balls, and sponge blocks, the dust in the welding fume is absorbed by the water, and the water that has absorbed the dust is discharged to the sewage treatment plant for treatment;

After step 5 and step 4 are completed, the welding fume that has absorbed most of the fume passes through the outlet pipe 6 and passes through the filter 7. The fume in the welding fume is further absorbed by the filter 7, and then discharged from the single-fan welding fume absorption purifier Clean room 1.

Using the single-fan welding fume absorption purifier of this embodiment to absorb and purify welding fume can solve the problem of welding fume polluting the working environment. The experimental test is carried out in the workshop, the test environment conditions: temperature 32 ℃, humidity 65%rh, inspection basis: GBZ/T 192.1-2007, the specific instructions are as follows: 1# sampling position is in the workshop without welding operation, the operator population Nose height, 0.5m away from the welding point, the total dust concentration is 2.2mg/ ^m3 ; 2# sampling position is in the welding process, the operator’s mouth and nose height, 0.5m away from the welding point, the total dust concentration is 4.6mg/m3 ³ ; 3# sampling position is after using the single fan welding fume absorption purifier of the present embodiment to absorb and purify, the height of operator's mouth and nose, at 0.5m away from the welding point, the total dust concentration is 2.6mg/m ; ⁴ # sampling position After absorption and purification by the single-fan welding fume absorption purifier of this embodiment, the total dust concentration outside the filter 7 at the upper end of the outlet pipe 6 is 2.4 mg/m ³ . The noise of the single fan welding smoke absorption purifier of the present invention is 65dB.

The above experimental test shows that after the single-fan welding fume absorption purifier of this embodiment absorbs and purifies, the height of the operator's mouth and nose, the total dust concentration (2.6mg/m ³ ) at the distance of 0.5m from the welding point is the same as that of the operator without welding operation The total dust concentration in the workshop is relatively close to (2.2mg/m ³ ), which shows that the technical solution of this embodiment can greatly improve the purification efficiency of welding fume and solve the problem of welding fume polluting the environment.

The above schematically describes the present invention and its implementation, which is not restrictive, and what is shown in the drawings is only one of the implementations of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, without departing from the inventive concept of the present invention, without creatively designing a structural mode and embodiment similar to the technical solution, it shall all belong to the protection scope of the present invention .

Claims (3)

1. a single blower fan weldering cigarette absorption cleaning device, comprises smoke absorbing mechanism, weldering cigarette purification mechanism and weldering cigarette follower, it is characterized in that:

Described smoke absorbing mechanism comprises blower fan (4), and weld fumes absorbs and is delivered to weldering cigarette purification mechanism by this blower fan (4);

Described weldering cigarette purification mechanism comprises clean room (1) and backflush device (2), it is inner that this backflush device (2) is positioned at clean room (1), and the bottom of this backflush device (2) is connected with clean room (1), scavenging solution is equipped with in clean room (1) inside, and weld fumes is delivered in the inner scavenging solution of backflush device (2) by above-mentioned blower fan (4); The backflush device (2) being positioned at clean room (1) inner is inverted cone-shaped structure, and the upper opening of this backflush device (2) is greater than its underpart opening, and this backflush device (2) inside is provided with steel wire lump and sponge block; Described clean room (1) top is provided with escape pipe (6), the upper end of this escape pipe (6) is provided with filter (7), described filter (7) comprises ground floor screen pack, steel wire lump and second layer screen pack, and described steel wire lump is arranged between ground floor screen pack and second layer screen pack;

Described weldering cigarette follower acts on smoke absorbing mechanism, follows the tracks of absorption weld fumes for controlling smoke absorbing mechanism with speed of welding.

2. one according to claim 1 single blower fan weldering cigarette absorption cleaning device, it is characterized in that: weldering cigarette purification mechanism also comprises discharging valve (3), described bottom, clean room (1) is provided with discharging valve (3).

3. one according to claim 2 single blower fan weldering cigarette absorption cleaning device, it is characterized in that: described smoke absorbing mechanism also comprises range hood (10), smoking hose (11), fan wind inleting tube (12) and fan outlet airduct (5), described range hood (10) is connected with fan wind inleting tube (12) by smoking hose (11), this fan wind inleting tube (12) L-shaped structure, the fan induced draught mouth of above-mentioned blower fan (4) is connected with one end of fan wind inleting tube (12), the other end of fan wind inleting tube (12) is closed, the backflush device (2) that the fan outlet of above-mentioned blower fan (4) is connected to weldering cigarette purification mechanism by fan outlet airduct (5) is inner, and fan outlet airduct (5) inserts the center that the inner position of backflush device (2) is backflush device (2).