JP2791390B2 - Self-cleaning type bag filter dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-cleaning type bag filter dust collector which jets jet air into a bag filter to remove dust from a filter element. It is an improvement.

[0002]

2. Description of the Related Art As a conventional apparatus of this type, for example, a bag filter dust collector disclosed in Japanese Patent Application Laid-Open No. 63-93318 is known. Further, the basic structure of the holding frame of the bag filter is known in the above publication and Japanese Patent Application Laid-Open No. 63-23709. In many cases, the holding frame is formed in a tubular frame shape by an annular shape holding frame and a longitudinal member fixed around the shape holding frame, and a bag-shaped filter element externally fitted to the holding frame is formed. The filtration surface wall is stretched and held by a longitudinal member.

[0003]

In the bag filter dust collector, the filtering area is increased by setting the size of the bag filter in the axial direction to be large, and the axial length reaches up to 5 m. In order to remove dust adhering to the elongated bag filter in this manner, pulsed jet air is blown out from an opening at one end of the bag filter to remove dust. However, a satisfactory dust removal effect can be obtained with the conventional device. Not. On the side of the bag farthest from the opening, dust adhering to the filter element can be reliably removed, but dust cannot be removed as it approaches the opening from the bag end. Even if the number of jet air jets or jet pressure is increased, there is no difference in the result. There is a dust removal mechanism in which a venturi cylinder is provided at the opening and the surrounding air is entrained by jet air and blown into the bag filter. However, even in this case, the same tendency as described above is exhibited, and the dust removal effect cannot be improved as far to the left.

Considering the above, it is supposed that the jet air inflates the surrounding filter surface wall only after hitting the back end wall of the bag filter to remove dust. I have to say that the department side is passing. As described above, in the conventional apparatus, dust removal from the filter element is insufficient, so that the actual filtration area is reduced, and as a result, the performance of the dust collector is reduced.

An object of the present invention is to improve the dust collection performance of this type of dust collector by ensuring that dust can be removed from the filter element and the state of the filter surface wall can always be maintained in an appropriate state. is there.

[0006]

According to the present invention, the jet air spouted into the bag filter is swirled so as to utilize the centrifugal force to collide the jet air with the wall of the filtration surface, expand the air, and filter the air. The dust is removed by blowing through the outer surface of the face wall. More specifically, the bag filter dust collector of the present invention is provided with a group of bag filters 5 inside the housing 1 and a dust removing mechanism 6 for ejecting the jet air-A for dust removal into each bag filter 5. That is, the bag filter 5 includes a bag-shaped filter element 11 having an open end, and a holding frame 12 that is inserted into the element 11 to hold the filter element 11 in an expanded state. Guide body 2 obliquely intersecting the traveling direction of the jet air-A inside
1 is required. Alternatively, a venturi cylinder 20 is provided between the nozzle 18 of the jet air-A and the opening of the bag filter 5, and a guide obliquely intersecting the traveling direction of the jet air-A on the inner surface of the venturi cylinder 20. It is required that the body 21 is provided. More specifically, the guide bodies 21 are provided in the holding frame 12 and / or the venturi cylinder 20 in one or more rows or spirally in the circumferential direction. More specifically, the guide body 21 is fixed to each of the longitudinal members 16 constituting the holding frame 12 in an intermittent spiral shape, or the guide shaft 23 whose shaft end is sharpened in a tapered shape.
And a continuous spiral helical blade 24 fixed along the peripheral surface of the guide shaft 23 to form a guide body 21, and the guide body 21 is arranged along the central axis of the holding frame 12. be able to.

[0007]

In the state where dust is removed, the jet air-A goes straight inside the bag filter 5. On the other hand, inside the holding frame 12 and / or the Venturi tube 20, a guide body 21 which obliquely intersects the traveling direction of the jet air-A is provided. As a result, the jet air-A collides with the guide body 21 and is guided by the guide body 21 to change the direction of the flow, forming a swirling airflow. It is inflated by rubbing against the inner surface of the face wall, part of which blows through to the outer surface of the filter face wall. When the guide body 21 is provided on the holding frame 12,
A part of the jet air-A collides with the guide body 21 and vibrates the holding frame 12 through the guide body 21 by the flow energy. Therefore, if the guide body 21 is arranged corresponding to a location where dust removal is difficult, dust adhering to the filter element 11 can be forcibly released.

[0008] The guide body 21 is connected to the guide shaft 23 and the spiral blade 2.
In the configuration in which the filter surface is arranged along the central axis of the holding frame 12, the filtration surface wall located around the spiral blade 24 can be almost and uniformly inflated.

[0009]

As described above, according to the present invention, the holding frame 12 of the bag filter 5 and / or the venturi cylinder 2 are provided.
0, a guide body 21 that obliquely intersects the traveling direction of the jet air-A is provided, and a part of the jet air-A jetted to the bag filter 5 collides with the guide body 21 and flows through the guide body 21 due to the collision. The filter element 11 is expanded and deformed by the centrifugal force of the swirling airflow whose direction has changed, and dust adhered to the outer surface is wiped off. Therefore, according to the bag filter dust collector of the present invention, dust can be reliably removed not only on the inner side of the filter element 11 but also on the opening side thereof, and the state of the filtration surface wall at the time of regeneration is always optimized. The performance of the dust collector can be improved.

[0010]

1 to 4 show an embodiment of a bag filter dust collector according to the present invention. In FIG. 2, a bag filter dust collector includes a hollow housing 1 and a partition wall 2.
Then, it is divided into a dust collecting chamber 3 occupying the majority and an exhaust chamber 4 on the upper side, and a group of bag filters 5 is inserted into the dust collecting chamber 3 from the exhaust chamber 4 side, and the upper end thereof is fixed to the partition wall 2. , Exhaust chamber 4
Is provided with a dust removal mechanism 6 inside. At the center of the bottom wall of the dust collection chamber 3, a dust extraction valve 7 for discharging dust separated from dust-containing air is provided. The dust-containing air is sent into the dust collection chamber 3 via the inlet 8 by an air supply device (not shown), and is filtered while passing through the bag filter 5 from the outer surface to the inner surface. The filtered clean air is taken out of the machine from an outlet 4 provided at the center of the upper wall of the exhaust chamber 4.

In FIG. 1, the bag filter 5 comprises a bag-shaped filter element 11 having an open end, and a cylindrical frame 12 for holding the element 11 in an extended state. The bag filter 5 is formed of a nonwoven fabric made of heat-resistant nylon, polyester, polypropylene fiber, or the like. The holding frame 12 has a base 13 at the upper end and a bottom cover 1 at the lower end.
4, and eight vertically extending members 16 are arranged at regular intervals along the periphery of the circular shape retaining frames 15 provided at regular intervals in the vertical direction as a shape retaining body. It is welded and fixed. After the filter element 11 is put on the holding frame 12 from the side of the bottom cover 14 and the entire peripheral surface of the holding frame 12 is covered, the opening edge is fixed to the base 13 with a stopper (not shown). The diameter and the vertical length of the bag filter 5 vary depending on the application, the amount of air to be processed, and the like.
The diameter is often 160 mm or less, and the vertical length is often 5 m or less.

The bag filters 5 are arranged in the housing 1 in rows and columns, and the dust contained in the dust-containing air is filtered to purify the air. If it is a material,
Collect and use this. A dust removing mechanism 6 is provided to remove dust adhering to the filter bag with the filtration and to regenerate the filtering surface wall to an appropriate state. This is achieved by arranging blow tubes 17 for each row of the bag filters 5 and providing a cleaning nozzle 18 on the lower surface of the blow tubes 17 corresponding to the upper opening of each bag filter 5, ie, the air outlet.
And each blow tube 17 is connected to a compressed air supply source 19 via an electromagnetic opening / closing valve and a header tube (not shown). When the electromagnetic on / off valve corresponding to each blow tube 17 is opened, the bag filter row located immediately below the blow tube 17 can be cleaned. The valve opening time at this time is about 0.05 to 0.1 second, and the jet air-A
Is ejected toward the inside of the bag filter 5. Between the nozzle 18 and the opening of the bag filter 5, there is provided a venturi cylinder 20 for entraining the surrounding air by utilizing the jetting action of the jet air-A.

With only the jet air-A, only the portion near the lower end of the filter element 11 is reliably removed. In order to compensate for this, as shown in FIG.
Are provided at a plurality of upper and lower locations inside the. The guide body 21 is made of a rectangular metal plate piece, and is arranged and welded to each longitudinal member 16 in an intermittent spiral shape. As shown in FIG. 3, the guide body 21 is attached to the longitudinal member 16 in an obliquely crossing state, and when the jet air-A passes, the airflow colliding with the guide body 21 is cut along the inclined surface. Guide and forcibly change the direction of the flow. The lower position of the guide body 21 is set to a position where dust removal by the jet air-A is insufficient. In the example of FIG. 1, the guide body 21 is provided in a spiral shape.
From the upper end side in the circumferential direction (at the same height position), or may be provided in a plurality of rows (a plurality of stages) or more at different height positions.

Next, the operation of the guide body 21 will be mainly described. The pressure of the jet air-A ejected from the nozzle 18 at the time of dust removal is, for example, 6 to 7 kg / cm 2, and the jet air-A travels straight at a high speed at the same time as ejected from the nozzle 18. For this reason, the jet air-A collides with the uppermost guide body 21 shortly before being jetted into the bag filter 5, and further reaches the inner bottom of the bag filter 5 while colliding with each of the guide bodies 21 of the next and subsequent stages one after another. As in the case of the conventional device, dust adhering to the lower end portion of the bag filter 5 is wiped off mainly by the impact of airflow and the expansion action.

As described above, the jet air-A moves at a high speed. Therefore, the guide body 21 colliding with the jet air-A is vibrated by the collision impact, and the vibration propagates to the longitudinal member 16. In other words, the longitudinal member 16 is vibrated downward from above by vibrating with a slight time difference. In addition, since the longitudinal members 16 supporting the guide body 21 are different for each stage, the eight longitudinal members 16 are alternately vibrated, and the filter element 11 which is in close contact with the outer surface thereof is fluttered in the radial direction. Let the dust off on the outer surface. A part of the jet air A is guided by the guide body 21 to form a swirling flow, which rubs the inner surface of the filter by the action of the centrifugal force, and expands the filter element 11 and descends while wiping off some air to the outer surface. And evenly remove dust adhering to the outer surface of the filter

That is, as shown in FIG. 3, the jet air-A that has collided with the guide body 21 is guided by the upper surface of the guide body 21 and changes the direction of the flow to become a swirling airflow. It collides with the filter surface wall located on the downward extension of the inclined surface of 21 so as to rub it, expands it outward, and partially blows through the filter surface wall. The dust adhering to the filter surface wall can be forcibly removed by the collision expansion deformation and the blow-through action of the filter element 11. The guide member 2 is attached to the longitudinal member 16 of the holding frame 12.
By providing 1, the dusting action due to the vibration of the holding frame 12 as described above is combined, and the dust adhering to the entire outer surface of the filter element 11 is surely separated, so that the filtration surface wall can be regenerated to an appropriate state. .

FIGS. 4 to 7 show modifications of the guide body 21. FIG. The guide body 21 shown in FIG. 4 forms a guide body 21 with a vertically long guide shaft 23 and a spiral blade 24 fixed along the peripheral surface of the guide shaft 23. , And are supported by a holding arm 25 fixed to the longitudinal member 16 or the shape retaining frame 15. The turning diameter of the spiral blade 24 is about 40% of the diameter of the holding frame 12, and there is a sufficient clearance around the circumference.
Tapered taper-shaped airflow guide surfaces 26 are formed at the upper and lower ends of the guide shaft 23. According to the guide body 21, the jet air is provided in the same manner as the guide body 21 of the above embodiment.
The holding frame 12 can be vibrated by the collision impact of A, and furthermore, the air flow that has separated from the blade surface without being able to follow the spiral shape of the spiral blade 24 allows the filtration surface wall around the blade to expand almost simultaneously, Dust can be removed.

The embodiment shown in FIG.
A guide body 26 similar to the guide body 21 described with reference to FIG.
It is characterized in that the airflow blown from zero is swirled. In the present invention, the guide 26 may be provided only on the venturi tube 20, or the guide 26 may be provided on the holding frame 12 together with the venturi tube 20.

The guide body 21 shown in FIG. 6 is formed of a metal plate piece having a partially arcuate shape. The guide body 21 obliquely intersects the longitudinal member 16 like the guide body 21 of FIG. Are fixed to the longitudinal member 16 in a state of being inclined downward in the radial direction by an angle θ with respect to the horizontal line. According to the guide body 21, the airflow is guided in a direction in which the circumferential inclination and the radial inclination are combined, so that the impact of the airflow on the filtration surface wall can be further increased.

The embodiment shown in FIG.
The guide bodies 26 described with reference to FIG. 5 are provided at four locations in a row in the circumferential direction only at the inner surface exit end of the guide. Each guide body 26 is approximately 15 degrees with respect to the central axis of the Venturi cylinder 20.
° tilted. In addition to the above, the guide body 21 is
Can be formed by fixing a metal wire rod in a continuous spiral shape on the inner surface of the metal wire. Furthermore, in the embodiment, each guide body 21
Are inclined in the same direction, but this is not necessary, and the inclination directions of the guide bodies 21 adjacent in the circumferential direction may be alternately reversed. In FIG. 1, the guide bodies 21 are arranged at equal pitches in the vertical direction, but the pitches in the vertical direction may be increased as approaching downward. Further, the area of the guide body 21 may be reduced as the area approaches the lower side. The bag filter 5 may have an envelope structure other than the cylindrical shape, and may be used in a form in which the bag filter 5 is disposed laterally on the housing.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a bag filter according to the present invention.

FIG. 2 is a longitudinal sectional view showing the principle structure of a self-cleaning type bag filter dust collector.

FIG. 3 is a longitudinal sectional view of a bag filter showing an operation of a guide body.

FIG. 4 is a vertical sectional view of a holding frame showing a modified form of the guide body.

FIG. 5 is a longitudinal sectional view showing a modified embodiment of the Venturi tube.

FIG. 6 is a longitudinal sectional view showing a modified form of the guide body.

FIG. 7 is a longitudinal sectional view showing a modified embodiment of the Venturi tube.

[Explanation of symbols]

1 ... housing, 5 ... bag filter, 6 ...
... Dust removal mechanism, 11 ... Filter element, 12 ...
... holding frame, 16 ... vertical member, 20 ... venturi tube, 21 ... guide body, 23 ... guide shaft, 24 ...
…… Spiral blade, A ……… Jet air

Claims (2)

(57) [Claims] 1. A self-cleaning type bag filter dust collector having a group of bag filters 5 inside a housing 1 and a dust removing mechanism 6 for jetting jet air A for dust removal inside each bag filter 5. The bag filter 5 includes a bag-shaped filter element 11 having an open end, and a holding frame 12 which is inserted into the element 11 to hold the filter element 11 in an extended state.
And a guide body 21 obliquely intersecting the traveling direction of the jet air A is provided inside the holding frame 12, and the guide body is provided in each of the longitudinal members 16 constituting the holding frame 12 with an intermittent spiral shape. Self-cleaning type bag filter dust collector fixed to. 2. A self-cleaning type bag filter dust collector provided with a group of bag filters 5 inside a housing 1 and a dust removing mechanism 6 for jetting jet air A for dust removal into the inside of each bag filter 5. The bag filter 5 includes a bag-shaped filter element 11 having an open end, and a holding frame 12 which is inserted into the element 11 to hold the filter element 11 in an extended state.
A guide body 21 is provided inside the holding frame 12 so as to obliquely intersect the traveling direction of the jet air A, and a guide shaft 23 whose shaft end is tapered in a tapered shape; And a continuous spiral helical blade 24 fixed along the peripheral surface of the guide frame 21, and a self-cleaning type bag filter dust collector in which the guide body 21 is disposed along the central axis of the holding frame 12. .