JPH0672621U - Bag cloth device filter cloth mounting structure - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a filter cloth mounting structure for a bag filter device which prevents leakage of untreated gas due to lifting of the filter cloth due to changes in operating conditions. [Structure] A filter chamber 1 and a clean gas chamber 2 are partitioned by a partition plate 4, and a plurality of filter cloths 3 attached to the partition plate 4 are provided as filter chambers 1.
In the bag filter device arranged inside, the partition plate 4 is formed with filter cloth attachment openings 41 corresponding to the number of filter cloths 3, and the filter cloth attachment openings 41 are formed in a cylindrical shape at the periphery thereof. An upper edge portion of the collar 5 is attached, and a protrusion 51 for preventing a fall and a protrusion 52 for preventing a rise are protruded inward from the collar 5 at predetermined intervals in the vertical direction.
The upper end of the filter cloth 3 is attached to the recess 53 formed between the two.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bag filter device that separates dust and suspended matter from a gas stream and removes or collects it.

[0002]

[Prior art]

 The types of bag filter devices currently in practical use are classified into four types, vibrating type, back pressure type, pulse jet type, and pulsation reverse feeding type, by the method of removing accumulated dust layer. Jet type is the most popular, and back pressure type tends to be adopted next.

In the case of the pulse jet type, the inflowing gas is filtered and neutralized on the outer surface of the filter cloth having an open upper end and rises up on the inner surface, so that the dust layer is deposited on the outer surface of the filter cloth and the high pressure air is filtered. It is generally sprayed off by spraying on the inner surface.

On the other hand, in the case of the back pressure type, the inflowing gas is filtered and neutralized by the inner surface of the filter cloth whose lower end is opened and rises on the outer surface, so that the dust layer is deposited on the inner surface of the filter cloth and is cleaned after the treatment. This is a method in which the gas is blown off from the outer surface of the filter cloth by backflow, and the gas flow to the filter cloth is completely opposite.

Here, the most general pulse jet method will be described as a typical example of the prior art.

FIG. 3 is a cross-sectional view showing a schematic configuration of a pulse jet bag filter device, and FIG. 4 and FIG. 4 are outlines of a filter cloth mounting structure for one of a plurality of filter cloths constituting the bag filter device. FIG.

In FIG. 3, a is a casing that houses a plurality of unit dust collecting mechanisms that constitute the bag filter device and separates them from each other, and a partition plate that suspends a plurality of filter cloths b on each unit dust collecting mechanism. It is divided by c into a lower filtration chamber d and an upper clean gas chamber e.

The clean gas chamber e is provided with a plurality of nozzles f for injecting compressed air from an air compression source (not shown) into each filter cloth b.

Below the filtration chamber d, a hopper chamber h for storing dust is formed, and a discharge mechanism j for discharging dust is connected to the bottom of the hopper chamber h.

On the outer side surface of the hopper chamber h, a main flue k for introducing the exhaust gas g containing soot and dust, acid harmful gas, etc. generated in an incinerator, a combustion furnace or the like (not shown) is disposed, and the exhaust gas g is It flows into each hopper chamber h 1 from a flue k via a branch flue m branched for each unit dust collecting mechanism, and reaches the surfaces of a plurality of filter cloths b suspended in the filtration chamber d.

Dust in the exhaust gas g is filtered when passing through the precoat layer on the surface of the filter cloth b, and the acidic harmful gas contained in the exhaust gas g is also neutralized by the agent forming the precoat layer. It becomes the clean gas p and is discharged to the clean gas chamber e, is sucked by an unillustrated draft fan through the discharge duct n, and is discharged into the atmosphere from a chimney (not shown).

In FIG. 4, a partition plate c disposed between the filter chamber d and the clean gas chamber e is for sealing the gas in both chambers and suspending the filter cloth b. An upper end edge of a cylindrical collar r, which is a metal fitting for filter cloth, is firmly fixed to the opening c1 for filter cloth attachment formed on the plate c by welding or the like. A fall prevention protrusion r1 is formed in an annular shape on the lower end edge of the collar r.

On the inner peripheral surface of the collar r, a filter cloth b1 for attachment, which is bent in a bag shape, is provided. Inside the filter cloth b1 for attachment, a flexible snap ring s is housed with a cushion material q such as felt attached to the outer periphery, and the external stretching force of the snap ring s and the fall prevention of the collar r are prevented. The mounting filter cloth b1 is pressed and held on the inner peripheral surface of the collar r by the supporting force of the projection r1.

The upper end of a tubular filter cloth body b2 is sewn to the lower edge of the filter cloth for attachment b1 containing the snap ring s and the cushion material q to form one body. The cloth body b2 and the cloth body b2 constitute a filter cloth b, which is suspended in the filtration chamber d for performing filtration and neutralization operations.

Further, inside the suspended filter cloth b, a retainer t formed into a cage shape by a plurality of vertical members and a plurality of annular members is arranged in order to withstand the external pressure of the gas flow during the filtering operation. It is set up.

Further, an upper end portion of the Venturi tube v is fixedly provided on an upper end portion of the retainer t. A flange v1 is formed at the upper end of the venturi pipe v, and the flange v1 is pressed against the peripheral edge of the filter cloth mounting opening c1 of the partition plate c by the pressing metal u so that the venturi pipe v and the retainer t are It is attached to the partition plate c. This venturi tube v flattens compressed air, which is sprayed from the dust layer sweeping nozzle accumulated on the surface of the filter cloth b, and clean air p, which is secondary air induced by the jet jet, into the filter cloth b. And so on.

Here, when replacing the filter cloth b, first, the nozzle f and the pressing metal u are removed, and then the venturi pipe v and the integrated retainer t are removed. Next, the snap ring s is bent inwardly in a concave shape to remove the mounting filter cloth b1 from the collar r, and the filter cloth body b2 is pulled up together with the mounting filter cloth b1 to be removed.

Further, at the time of mounting, the mounting filter cloth b1 and the filter cloth body b2 are inserted into the collar r, and the snap ring s is pushed and bent to mount the mounting filter cloth b1 into the collar r, and then released. The filter cloth b is suspended in the filter chamber d.

After that, the Venturi tube v and the retainer t are inserted into the tube of the filter cloth b, fixed by the holding metal fitting r, and finally the nozzle f is attached.

[0020]

[Problems to be solved by the device]

 During operation of the bag filter device configured as described above, the levitation force is applied to the venturi pipe v and the retainer t by the cleaning gas p rising in the filter cloth b.

The bag filter device is automatically controlled so as to keep the differential pressure inside and outside the filter cloth b below a certain value, but if the differential pressure rises above the limit due to a failure of the control system, etc. The suction force of the machine exerts an upward suction force on the filter cloth b, and a rising pressure is applied to the retainer t supported inside.

It is the press fitting u that suppresses both of these rising forces, which fixes the venturi pipe v and the retainer t to the partition plate c, and the flange v1 of the venturi pipe v allows the filter cloth b to move. It restrains the rise.

However, since the holding metal fittings u are not provided in a large number in a narrow place and are in an atmosphere that is easily corroded, the fitting and removing work thereof is extremely complicated.

In addition, since the fitting state between the collar r and the mounting filter cloth b1 is gradual, when the mounting filter cloth b1 floats up due to corrosion of the presser u or forgetting to tighten it, the collar r There was a problem in that an exhaust gas g leaked to the clean gas chamber e due to the formation of a gap between the mounting filter cloth b1 and the mounting filter cloth b1.

[0025]

[Means for Solving the Problems]

 The filter cloth mounting structure of the bag filter device of the present invention is a bag filter device in which a filter chamber and a clean gas chamber are partitioned by a partition plate, and a plurality of filter cloths mounted on the partition plate are arranged in the filter chamber. Corresponding to the number of the filter cloths, openings for filter cloth attachment are formed on the partition plate, and an upper edge of a cylindrical collar is attached to a peripheral edge forming the openings for filter cloth attachment. The projections for preventing fall and the projections for preventing floating are projected inward at a predetermined interval in the vertical direction, and the upper end of the filter cloth is mounted in the recess formed between these projections. It is a thing.

[0026]

[Action]

 By providing the collar with a drop prevention protrusion and a protrusion preventing protrusion, and by mounting the upper end of the filter cloth in this recess, the filter cloth can be stably arranged on the collar regardless of the vertical movement of the filter cloth. To do.

[0027]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a filter cloth mounting structure of a bag filter device according to the present invention.

The entire structure of the bag filter device is the same as the structure described in the section of the related art, and the details are omitted.

A partition plate 4 is provided between the filtration chamber 1 and the clean gas chamber 2 for sealing the gas in both chambers and suspending the filter cloth 3.

The partition plate 4 is provided with filter cloth attachment openings 41 for attaching a plurality of filter cloths 3 corresponding to the number of the filter cloths. An upper end edge of a cylindrical collar 5 which is a metal fitting for filter cloth is firmly fixed to the peripheral edge forming the filter cloth fitting opening 41 by welding or the like.

The collar 5 has a ring-shaped drop prevention protrusion 51 projecting inward at a lower end thereof, and is formed inward at an intermediate portion of the collar 5 spaced a predetermined distance from the fall prevention protrusion 51. The protruding prevention protrusion 52 is formed, whereby an annular recess 53 is formed between the fall prevention protrusion 51 and the protrusion prevention protrusion 52.

A filter cloth 31 for attachment, which is bent in a bag shape, is disposed in the recess 53, and a flexible snap ring 32 has a cushion material 33 such as felt inside the filter cloth 31 for attachment. It is attached and stored on the outer circumference. Therefore, when the outward stretching force of the snap ring 32 is applied to the mounting filter cloth 31 via the cushion material 33, the mounting filter cloth 31 is pressed into the recess 53.

The upper edge of the tubular filter cloth body 34 is sewn to the lower edge of the attachment filter cloth 31, so that both parties integrally form the filter cloth 3 for performing filtration and neutralization work. It is suspended in the filtration chamber 1.

Inside the filter cloth 3 suspended in this way, the retainer 6 formed in a cage shape by the plurality of vertical members 61 and the plurality of annular members 62 is inserted, and the pressure of the gas flow during the filtering operation is inserted. Is designed to withstand.

Further, the upper end of the retainer 6 is fixedly provided with the upper end of the Venturi tube 7. A flange 71 is formed on the upper end of the venturi pipe 7, and the flange 71 is mounted on the peripheral edge of the filter cloth mounting opening 41 of the partition plate 4 so as to be fixed to the venturi pipe 7 and the venturi pipe 7. The retainer 6 is held by the partition plate 4.

As described above, since the venturi pipe 7 and the retainer 6 are a mechanism that can be freely raised with respect to the partition plate 4, there is no need for a holding metal fitting as in the conventional method, and the replacement work of the filter cloth 3 is performed. Will be easier.

This Venturi pipe 7 uses compressed air ejected from the dust layer wiping nozzle accumulated on the surface of the filter cloth 3 and secondary air induced by the jet jet when the dust layer is blown off. This is for evenly distributing certain clean air 9 in the filter cloth 3.

Next, the state of the filter cloth 3 during operation of the bag filter device configured as described above will be described.

Exhaust gas 8 generated in an incinerator, a combustion furnace, or the like (not shown) is filtered and neutralized by passing through a precoat layer formed on the surface of the filter cloth body 34 to become a clean gas 9, and is filtered. It rises in the cloth body 34, enters the clean gas chamber 2 through the Venturi pipe 7, is sucked by an unillustrated draft fan, and is discharged to the outside.

When the flow rate of the exhaust gas 8 flowing into the unit dust collection mechanism increases during the main operation, the flow velocity of the cleaning gas 9 increases and the venturi pipe 7 and the retainer 6 are pushed up. The flange 71 is separated from the partition plate 4 to form a bypass flow path, and the rising pressure force is dispersed, so that the equilibrium state is maintained at an appropriate position.

Further, when the dust layer thickness adhering to the surface of the filter cloth 3 becomes excessive due to a failure of the internal / external differential pressure control system of the filter cloth 3 and the differential pressure rises above the limit, the suction force of an unillustrated draft fan causes The filter cloth main body 34 is sucked upward, and a phenomenon occurs in which the retainer 6 and the venturi pipe 7 which are internally supported are sucked up.

As a result, similar to the above, a bypass flow path is formed, the internal and external differential pressure of the filter cloth 3 is reduced, and an equilibrium state is created at an appropriate position.

The mounting filter cloth 31 is stably held in the recess 53 provided in the collar 5 regardless of the increase in the flow rate of the exhaust gas 8 and the increase in the internal / external pressure difference of the filter cloth 3 described above. Moreover, even if the retainer 6, the venturi pipe 7, and the filter cloth body 34 move up and down, the untreated exhaust gas 8 does not leak from the filtration chamber 1 to the clean gas chamber 2.

In this example, the collar 5 is bent to form a fall prevention protrusion 51 and a rise prevention protrusion 52 as a fall prevention and rising prevention mechanism provided on the collar 5. It may have a welded structure, or an appropriate number of protrusions may be dispersedly arranged on the inner peripheral surface of the collar 5.

Further, the retainer 6 and the venturi pipe 7 have a structure in which they can be raised freely just by placing them on the partition plate 4. However, a stopper for restricting the rise is provided above and abutted on this stopper. At this time, a mechanism for issuing an abnormal signal may be added.

FIG. 2 shows another embodiment of the filter cloth mounting structure of the bag filter device according to the present invention. The same members as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The collar 100 has a ring-shaped drop prevention protrusion 101 protruding inwardly at the lower end thereof, and an annular mounting portion 102 having a U-shaped cross-section also serving as a floating prevention protrusion at the upper end edge. It was formed in. The collar 100 is held by the partition plate 4 by fitting the opening of the mounting part 102 into the periphery of the filter cloth mounting opening 41 of the partition plate 4.

An annular recess 103 is formed between the drop preventing protrusion 101 and the mounting portion 102, and the mounting filter cloth 31 is mounted in the recess 103 via a snap ring 32 and a cushion material 33. To be done.

[0050]

[Effect of device]

 As described above, according to the present invention, the collar is provided with the concave portion formed by the drop prevention protrusion and the floating prevention protrusion, and the upper end portion of the filter cloth is attached to the concave portion, so that the filter cloth becomes the collar. Stable arrangement.As a result, the untreated exhaust gas leaks from the filter chamber to the clean gas chamber even if the filter fabric moves up and down due to the increase in the exhaust gas flow rate and the increase in the differential pressure between the filter cloth. There is no. Moreover, since the upper part of the filter cloth is mounted in contact with the recess of the collar over a wide area, it is not necessary to use a specific material because a local load is not applied.

[Brief description of drawings]

FIG. 1 is a sectional view showing a filter cloth mounting structure of a bag filter device according to the present invention.

FIG. 2 is an enlarged sectional view showing another embodiment of the filter cloth mounting structure of the bag filter device according to the present invention.

FIG. 3 is a cross-sectional view showing a schematic configuration of a general bag filter device.

FIG. 4 is a cross-sectional view showing a conventional filter cloth mounting structure.

[Explanation of symbols]

 1 Filter Chamber 2 Clean Gas Chamber 3 Filter Cloth 4 Partition Plate 41 Filter Cloth Attachment Opening 5 Collar 51 Fall Prevention Protrusion 52 Float Prevention Protrusion 53 Recess 100 Collar 100 Fall Prevention Protrusion 102 Mounting 103 Recess

Claims (1)

[Scope of utility model registration request] 1. A bag filter device in which a filter plate is divided into a filter chamber and a clean gas chamber by a partition plate, and a plurality of filter cloths attached to the partition plate are arranged in the filter chamber, wherein the partition plate is the filter cloth. Corresponding to the number of the filter cloth attachment openings are formed, and the upper edge of the cylindrical collar is attached to the periphery forming the filter cloth attachment opening. A bag filter characterized in that a drop-preventing projection and a floating-preventing projection are projected inwardly at a distance from each other, and an upper end of the filter cloth is mounted in a recess formed between the projections. Device filter cloth mounting structure.