CN113041764B

CN113041764B - Bag filter

Info

Publication number: CN113041764B
Application number: CN202110301458.0A
Authority: CN
Inventors: 张立宁; 姜利霞; 李少华
Original assignee: China ENFI Engineering Corp
Current assignee: China ENFI Engineering Corp
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2023-02-28
Anticipated expiration: 2041-03-22
Also published as: CN113041764A

Abstract

The application discloses bag filter includes: the outer cylinder body is provided with a first air outlet and a first discharge port; the filter bag assembly is arranged in the outer cylinder body; the inner cyclone cylinder is arranged in the outer cylinder body and is provided with a first air inlet, a second solid discharge port and a second air outlet, and the second solid discharge port is positioned above the first solid discharge port; the first end of the air inlet pipe extends into the outer cylinder body, and the first end of the air inlet pipe is connected with the first air inlet. Therefore, the bag filter provided by the embodiment of the invention has the advantages of long service life, high solid-containing gas filtering efficiency, small size, small occupied area and the like.

Description

Bag filter

Technical Field

The invention relates to titanium dioxide production equipment by a chlorination method, in particular to a bag filter.

Background

The method comprises the steps of carrying out chlorination reaction on raw material high-titanium slag and chlorine in a chlorination furnace with the participation of petroleum coke to generate crude titanium tetrachloride, cooling and purifying the crude titanium tetrachloride to obtain refined titanium tetrachloride, carrying out oxidation reaction on the refined titanium tetrachloride and oxygen in an oxidation reactor to generate titanium dioxide (titanium dioxide base material) and chlorine, cooling a gas phase (200-450 ℃) carrying the titanium dioxide base material (containing scab removing sand sprayed in the oxidation reactor) through a cooling conduit, then feeding the cooled gas phase to a bag filter for gas-solid separation, feeding the separated solid phase (the titanium dioxide base material) to a size mixing tank for size mixing, and then feeding the gas phase to the chlorination furnace for recycling.

In the related technology, because the solid content in the material is very high, the designed filtering air speed is low, the required filtering area is very large, the size of the bag filter is very large, and the material and the occupied space are wasted; the incoming material air velocity is very high, and can cause the impact to the inner wall of bag filter and filter bag after entering the bag filter, and the inner wall of bag filter and filter bag wearing and tearing are serious, influence life.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, embodiments of the present invention provide a bag filter.

A bag filter according to an embodiment of the invention comprises:

the outer cylinder body is provided with a first air outlet and a first discharge port;

the filter bag assembly is arranged in the outer barrel;

the inner cyclone cylinder is arranged in the outer cylinder body and provided with a first air inlet, a second solid discharge port and a second air outlet, and the second solid discharge port is positioned above the first solid discharge port; and

the first end of the air inlet pipe extends into the outer cylinder body, and the first end of the air inlet pipe is connected with the first air inlet.

Therefore, the bag filter provided by the embodiment of the invention has the advantages of long service life, high solid-containing gas filtering efficiency, small size, small occupied area and the like.

In some embodiments, the inner cyclone cartridge comprises:

the side surface of the upper cylinder body is provided with the first air inlet, and the upper end part of the upper cylinder body is provided with the second air outlet; and

the upper end part of the lower barrel is connected with the lower end part of the upper barrel, the lower end part of the lower barrel is provided with the second row fixing port, optionally, the lower barrel is conical, the lower end opening of the lower barrel is smaller than the upper end opening of the lower barrel, and the lower end opening of the lower barrel forms the second row fixing port.

In some embodiments, the inner wall of the upper cylinder is provided with a spiral flow guide plate, the spiral flow guide plate has a downward flow guide direction, and the flow guide direction of the spiral flow guide plate is tangential to the opening direction of the first air inlet.

In some embodiments, the air conditioner further comprises an inner air draft tube, an upper end portion of the inner air draft tube is connected with the second air outlet, and the inner air draft tube extends downwards from the second air outlet.

In some embodiments, the bag filter further includes a hood located above the second outlet, the hood being opposite to the second outlet in the up-down direction, a projected edge of the second outlet in the horizontal plane being located inside the projected edge of the hood in the horizontal plane, and optionally, the hood is conical.

In some embodiments, the upper barrel comprises:

the side surface of the body is provided with the first air inlet; and

the lower end part of the end socket is connected with the upper end part of the body, the upper end part of the end socket is provided with the second air outlet, the end socket is in a round table shape, the upper end part of the end socket is smaller than the lower end part of the end socket, and the spiral guide plate is arranged on the inner wall of the end socket.

In some embodiments, the opening direction of the first air inlet is tangential to the inner wall of the inner cyclone cylinder, and optionally, the extending direction of the air inlet pipe is tangential to the inner wall of the inner cyclone cylinder.

In some embodiments, a flower plate is arranged in the outer cylinder body, the flower plate divides the outer cylinder body into a clean air chamber and a bag filter chamber, the filter bag assembly is mounted on the flower plate, the filter bag assembly is located in the bag filter chamber, the first air outlet is communicated with the clean air chamber, the first fixing outlet is communicated with the bag filter chamber, and the inner cyclone cylinder is arranged in the bag filter chamber.

In some embodiments, the spiral deflector comprises a first spiral deflector and a second spiral deflector, an upper end of the first spiral deflector is positioned above the first air inlet, and an upper end of the second spiral deflector is positioned above a lower end of the first spiral deflector.

In some embodiments, the bag filter further includes a screen ring, an inner end of the screen ring is connected to the inner cyclone cylinder, an outer end of the screen ring is connected to the outer cylinder, the screen ring is provided with a row of fixing ports penetrating through the screen ring in the up-down direction, optionally, the inner end of the screen ring is connected to a lower end of the inner cyclone cylinder, and the outer end of the screen ring is located below the inner end of the screen ring.

Drawings

Fig. 1 is a schematic structural view of a bag filter according to an embodiment of the present invention.

FIG. 2 is a schematic structural view of an outer housing of a bag filter according to an embodiment of the invention.

Fig. 3 is a schematic structural diagram of a front view of a head according to an embodiment of the invention.

Fig. 4 is a schematic structural diagram of a top view of a head according to an embodiment of the invention.

Fig. 5 is a schematic structural diagram of a top view of a head according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.

A bag filter 1000 according to an embodiment of the present invention is described below with reference to the accompanying drawings. As shown in fig. 1 to 5, a bag filter 1000 according to an embodiment of the present invention includes an outer cylinder 100, a filter bag assembly 200, an inner cyclone cylinder 300, and an intake duct 400.

The outer cylinder 100 has a first air outlet 110 and a first fixing outlet 120. The filter bag assembly 200 is provided in the outer cylinder 100. The inner cyclone tube 300 is installed in the outer cylinder 100, the inner cyclone tube 300 has a first air inlet 320, a second discharge port 330 and a second air outlet 340, and the second discharge port 330 is located above the first discharge port 120. A first end portion of the air inlet pipe 400 extends into the outer cylinder 100, and the first end portion of the air inlet pipe 400 is connected to the first air inlet 320.

For gas with high solid content, when the flow rate of the gas is high, the gas impacts the inner wall of the outer cylinder 100 and the filter bag assembly 200, the inner wall of the outer cylinder 100 and the filter bag assembly 200 are seriously worn, and the service life is influenced. When the gas flow rate is reduced, in order to increase the filtering rate and prevent solid particles from blocking the filter bag assembly 200 to cause rapid pressure drop rise, the required filtering area is large, the size of the bag filter is large, and materials and occupied space are wasted.

The bag filter 1000 according to the embodiment of the present invention is provided with the inner cyclone 300, and the inner cyclone 300 is installed in the outer cylinder 100, so that the solid-containing gas firstly enters the inner cyclone 300 to perform the first gas-solid separation. Therefore, the solid content of the solid-containing gas can be effectively reduced, so that the impact and the abrasion of the solid-containing gas to the outer cylinder 100 and the filter bag assembly 200 can be effectively reduced, the service life of the cylinder 100 and the filter bag assembly 200 can be prolonged, and the overall filtering efficiency of the solid-containing gas can be effectively improved.

In addition, the solid content of the gas containing solid is effectively reduced through the first gas-solid separation, so that the flow rate of the gas containing solid flowing through the filter bag can be properly increased. Thereby, the size of the filter bag assembly 200 can be effectively reduced, and thus the size of the bag filter 1000 can be effectively reduced.

The solid-containing gas with the reduced solid content rate is filtered in the outer cylinder 100 to realize secondary gas-solid separation, and because the large granular materials in the solid-containing gas with the reduced solid content rate are few, the impact of the solid-containing gas on the inner wall of the outer cylinder 100 and the filter bag assembly 200 is small during filtering, so that the service life of the inner wall of the outer cylinder and the service life of the filter bag assembly 200 can be prolonged. Meanwhile, the speed of the solid-containing gas flowing through the filter bag can be improved, the filter area and the size of the filter bag assembly 200 are reduced, and the filter efficiency of the solid-containing gas is improved.

Therefore, the bag filter 1000 according to the embodiment of the present invention has advantages of long service life, high solid-containing gas filtration efficiency, small size, small floor space, and the like.

As shown in fig. 1 to 5, a bag filter 1000 according to an embodiment of the present invention includes an outer cylinder 100, a filter bag assembly 200, an inner cyclone 300, and an air inlet duct 400.

As shown in fig. 1, in some embodiments, the outer cylinder 100 has a first air outlet 110 and a first fixing outlet 120, and a flower plate 130 is provided in the outer cylinder 100. The faceplate 130 divides the outer cylinder 100 into a clean air plenum 140 and a baghouse 150, the clean air plenum 140 being above the baghouse 150. The up-down direction is shown by arrow a in fig. 1.

The filter bag assembly 200 is mounted on the card 130 inside the outer cylinder 100, and the filter bag assembly 200 is located under the card 130. The filter bag assembly 200 is located within the baghouse 150 and filters the solids laden gas within the baghouse 150 such that particles in the solids laden gas remain within the baghouse 150 and the gas in the solids laden gas can enter the clean air plenum 140. The first outlet port 110 is in communication with the clean air plenum 140 and the first discharge port 120 is in communication with the baghouse. Accordingly, the filtered gas is discharged out of the outer drum 100 from the first gas outlet 110, and the solids intercepted by the gas outlet 200 may be discharged out of the outer drum 100 from the first solids discharge port 120.

In some embodiments, a blowing assembly is disposed on the faceplate 130, and the blowing assembly can blow the filter bag assembly 200. The blow assembly may blow off solid particles attached to the filter bag assembly 200 to clean the filter bag assembly 200.

As shown in FIG. 1, in some embodiments, the inner cyclone cartridge 300 is mounted within the outer cartridge body 100, the inner cyclone cartridge 300 including an upper cartridge body 310 and a lower cartridge body 314.

The upper cylinder 310 includes a body 311 and a cap 312. The side surface of the body 311 is provided with a first air inlet 320, and the opening direction of the first air inlet 320 is tangential to the inner wall of the inner cyclone barrel 300. Specifically, the opening direction of the first gas inlet 320 is tangential to the inner wall of the body 311, so that the solid-containing gas entering the body 311 from the first gas inlet 320 can flow spirally along the inner wall of the body 311. The end socket 312 is circular truncated cone-shaped, and the upper end of the end socket 312 is smaller than the lower end of the end socket 312, so that when the solid particles intercepted by the filter bag assembly 200 fall on the outer peripheral surface of the end socket 312, the solid particles can slide along the outer peripheral surface of the end socket 312. The lower end of the sealing head 312 is connected with the upper end of the body 311, and the upper end of the sealing head 312 is provided with a second air outlet 340.

The upper end of the lower cylinder 314 is connected to the lower end of the upper cylinder 310, and the lower end of the lower cylinder 314 is provided with a second row of fixing openings 330. The second row of fastening ports 330 is located above the first row of fastening ports 120. The lower cylinder 314 is tapered, the lower end opening of the lower cylinder 314 is smaller than the upper end opening of the lower cylinder 314, and the lower end opening of the lower cylinder 314 forms a second row of fixing ports 330.

After the solid-containing gas enters the inner cyclone 300 from the first gas inlet 320, the solid-containing gas spirals downward along the inner wall of the body 311. The solid-containing gas rotates at high speed on the side wall in the body 311, and the high-concentration solid particles rub and collide with each other. Under the action of various interaction forces such as electrostatic force, van der waals force and the like, solid particles are gathered together to form larger particles, gas-solid separation is realized under the action of centrifugal force, and the inner cyclone barrel 300 is discharged from the second solid discharge port 330, so that the solid content of solid-containing gas is reduced. The center of the inner cyclone 300 will have a low pressure area due to the centrifugal force during the cyclone process. After the solid-containing gas with low solid content enters the conical lower cylinder 314, the diameter of the inner cyclone cylinder 300 is reduced, so that the solid-containing gas with low solid content enters the central low-pressure area, the solid-containing gas with low solid content spirally flows upwards under the action of pressure difference, and finally the solid-containing gas with low solid content is discharged out of the inner cyclone cylinder 300 through the second gas outlet 340.

As shown in fig. 3-5, in some embodiments, the inner wall of the upper barrel 310 is provided with a first spiral deflector 352. Specifically, a first spiral flow guide plate 352 is disposed on the inner wall of the head 312, the first spiral flow guide plate 352 has a downward flow guide direction, and the flow guide direction of the first spiral flow guide plate 352 is tangential to the opening direction of the first air inlet 320. Wherein, the upper end of the first spiral baffle 352 is located above the first air inlet 320.

After the solid-containing gas enters the inner cyclone 300 from the first gas inlet 320, most of the solid-containing gas flows downwards, and the small part of the solid-containing gas flows upwards. For convenience of description, the portion of the solid-containing gas flowing upward will be referred to as a first solid-containing gas. 350 may direct the first solids-containing gas to flow downwardly. The first solids-containing gas forms a downward swirl during the downward flow along 350. And a downward rotational flow is formed, so that the first solid-containing gas is converged into the main gas flow, and solid particles are mutually rubbed and collided to form large particles in the continuous rotational flow process, thereby achieving the purpose of gas-solid separation.

As shown in fig. 3 and 5, the inner wall of the upper cylinder 310 is provided with a second spiral flow-guiding plate 351. Specifically, the inner wall of the end enclosure 312 is provided with a second spiral guide plate 351, the second spiral guide plate 351 has a downward flow guiding direction, and the flow guiding direction of the second spiral guide plate 351 is tangential to the opening direction of the first air inlet 320. The upper end of the second spiral baffle 351 is located above the lower end of the first spiral baffle.

The majority of the first solids laden gas will continue to spiral downward after exiting the lower end of the first spiral deflector 352 (after exiting the first spiral deflector 352), and the minority of the first solids laden gas will flow upward after exiting the lower end of the first spiral deflector 352. By providing the second spiral baffle 351 and positioning the upper end of the second spiral baffle 351 above the lower end of the first spiral baffle, the flow of the small portion of the first solid-containing gas in the second pair can be guided so that the small portion of the first solid-containing gas flows downward. The small part of the first solid-containing gas forms downward rotational flow in the downward flowing process, the downward rotational flow is formed to enable the gas flow to be converged into the main gas flow, and solid particles rub and collide with each other in the rotational flow process to form large particles, so that the purpose of gas-solid separation is achieved.

In some embodiments, there are a plurality of spiral flow deflectors 350, and the plurality of spiral flow deflectors 350 can effectively guide the first solid-containing gas.

A first end portion of the air inlet pipe 400 extends into the outer cylinder 100, and the first end portion of the air inlet pipe 400 is connected to the first air inlet 320. The solid-containing gas enters the inner cyclone 300 through the gas inlet pipe 400.

Optionally, the extending direction of the air inlet pipe 400 is tangent to the inner wall of the inner cyclone tube 300, so that the solid-containing gas coming out of the air inlet pipe 400 can be better tangent to the inner wall of the inner cyclone tube 300, and the solid-containing gas can form a spiral airflow conveniently.

In some embodiments, bag filter 1000 further includes an inner draft tube 341 and a hood 342.

The upper end of the inner gas riser 341 is connected to the second gas outlet 340, and the inner gas riser 341 extends downward from the second gas outlet 340. The gas inlet of the inner draft tube 341 is located at the center, and the solid-containing gas having a high solid content (solid-containing gas that has not been subjected to the spiral flow) that has gone up from the inner wall of the inner cyclone 300 does not easily reach the gas inlet of the inner draft tube 341. The solid-containing gas with low solid content can pass through the second gas outlet 340 through the inner gas rising pipe 341, and the solid-containing gas with high solid content (the solid-containing gas which does not undergo the spiral gas flow) is difficult to pass through the second gas outlet 340 through the inner gas rising pipe 341, so the inner gas rising pipe 341 can enhance the effect of the first gas-solid separation of the solid-containing gas.

The hood 342 is located above the second air outlet 340, and the hood 342 is opposite to the second air outlet 340 in the up-down direction. The projected edge of second air outlet 340 in the horizontal plane is located inside the projected edge of hood 342 in the horizontal plane, i.e. the coverage area of hood 342 is larger than the outlet area of second air outlet 340. The low solid content solids-containing gas is dispersed through the funnel cap 342, so that the impact of the low solid content solids-containing gas on the filter bag assembly 200 is smaller, and the service life of the filter bag assembly 200 is further prolonged.

Optionally, the funnel cap 342 is conical, so that solids falling from the filter bag assembly 200 can smoothly slide off and cannot be accumulated on the funnel cap.

In some embodiments, the bag filter 1000 further includes a screen ring 500, an inner end of the screen ring 500 is connected to the inner cyclone tube 300, an outer end of the screen ring 500 is connected to the outer cylinder 100, and the screen ring 500 is provided with a discharge port penetrating the screen ring 500 in an up-down direction. The solid particles falling from the outer cylinder 100 fall from the discharge port of the sieve ring 500, and the sieve ring 500 and the falling solid particles make the second discharge port 330 of the inner cyclone 300 not communicate with the baghouse 150 of the outer cylinder 100, preventing the solid-containing gas from entering the baghouse 150 of the outer cylinder 100 from the second discharge port 330.

Moreover, a relatively closed space is defined among the outer cylinder body 100, the inner cyclone cylinder 300 and the sieve ring 500, and after part of gas enters the space between the sieve ring 500 and the second discharge port 330, the pressure of the space is increased, so that other solid-containing gas is prevented from entering the space between the sieve ring 500 and the second discharge port 330, most of the solid-containing gas is discharged out of the inner cyclone cylinder 300 from the second gas outlet 340, and the effect of the first gas-solid separation of the solid-containing gas is enhanced.

Optionally, the inner end of the screen ring 500 is connected to the lower end of the inner cyclone tube 300 and the outer end of the screen ring 500 is located below the inner end of the screen ring 500. The outer end of the screen ring 500 is positioned below the inner end of the screen ring 500 such that the outer end of the screen ring 500 is proximate to the first row of fastening ports 120 such that the relatively enclosed space defined between the basket 100, the inner cyclone basket 300 and the screen ring 500 is small, effectively preventing solids laden gas from entering the baghouse 150 of the outer basket 100 from the second row of fastening ports 330.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, but are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" and the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A bag filter, comprising:

the outer cylinder body is provided with a first air outlet and a first fixing outlet;

the filter bag assembly is arranged in the outer barrel;

the inner cyclone cylinder is arranged in the outer cylinder and comprises a first air inlet, a second row of fixing ports and a second air outlet, the second row of fixing ports is positioned above the first row of fixing ports, the inner cyclone cylinder comprises an upper cylinder body and a lower cylinder body, the side surface of the upper cylinder body is provided with the first air inlet, the upper end part of the upper cylinder body is provided with the second air outlet, the upper end part of the lower cylinder body is connected with the lower end part of the upper cylinder body, the lower end part of the lower cylinder body is provided with the second row of fixing ports, the inner wall of the upper cylinder body is provided with a spiral flow guide plate, the spiral flow guide plate comprises a first spiral flow guide plate and a second spiral flow guide plate, the upper cylinder body comprises a body and a seal head, the side surface of the body is provided with the first air inlet, the lower end part of the seal head is connected with the upper end part of the body, the upper end part of the seal head is provided with the second air outlet, the first spiral flow guide plate and the second spiral flow guide plate are arranged on the inner wall of the seal head, the first spiral flow guide plate and the second spiral flow guide plate are positioned above the upper end part of the first spiral flow guide plate, and the second spiral flow guide plate are tangential to the upper end part of the first spiral flow guide plate;

the first end part of the air inlet pipe extends into the outer cylinder body, and the first end part of the air inlet pipe is connected with the first air inlet;

the opening direction of the first air inlet is tangent to the inner wall of the inner cyclone cylinder, and the extending direction of the air inlet pipe is tangent to the inner wall of the inner cyclone cylinder;

the upper end part of the inner gas lift pipe is connected with the second gas outlet, and the inner gas lift pipe extends downwards from the second gas outlet;

the blast cap is positioned above the second air outlet, the blast cap and the second air outlet are opposite in the vertical direction, and the edge of the projection of the second air outlet on the horizontal plane is positioned on the inner side of the edge of the projection of the blast cap on the horizontal plane;

the inner end part of the screen ring is connected with the inner cyclone cylinder, the outer end part of the screen ring is connected with the outer cylinder body, a discharge port penetrating through the screen ring along the vertical direction is formed in the screen ring, the inner end part of the screen ring is connected with the lower end part of the inner cyclone cylinder, and the outer end part of the screen ring is positioned below the inner end part of the screen ring;

a relatively closed space is defined among the outer cylinder body, the inner cyclone cylinder and the sieve ring.

2. The bag filter of claim 1, wherein the lower cylinder is tapered, the lower cylinder having a lower end opening smaller than an upper end opening of the lower cylinder, the lower end opening of the lower cylinder constituting the second row of fastening ports.

3. The bag filter of claim 1, the hood being conical.

4. The bag filter of claim 1, wherein the head is frustoconical, and an upper end of the head is smaller than a lower end of the head.

5. The bag filter of claim 1, wherein a flower plate is provided in the outer cylinder, the flower plate divides the outer cylinder into a clean air chamber and a bag filter chamber, the filter bag assembly is mounted on the flower plate, the filter bag assembly is located in the bag filter chamber, the first air outlet is communicated with the clean air chamber, the first exhaust port is communicated with the bag filter chamber, and the inner cyclone cylinder is provided in the bag filter chamber.