JPH0664708U - Venturi tube mounting structure for bag filter device - Google Patents

Abstract

(57) [Abstract] [Purpose] By reducing the pressure loss in the venturi pipe part of the bag filter device, the load on the induction fan is reduced and the dust adhering to the upper part of the filter cloth where the venturi pipe is located is removed. A Venturi tube mounting structure that facilitates A filter chamber 1 and a clean gas passage 4 are divided by a partition plate 3 having a filter cloth 2, and the filter chamber 1 and the clean gas passage 4 are separated.
In the bag filter device in which and are communicated with each other through the filter cloth 2 and the venturi tube 7 provided on the filter cloth 2, the venturi tube 7 has the void 8 in the peripheral portion thereof and the partition plate 3
The filter cloth 2 and the clean gas passage 4 are connected to each other through the gap 8 and the venturi pipe 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bag filter device for separating and removing dust and suspended matter from a gas flow, and more particularly to a mounting structure of a bench tube provided in an upper part of a filter cloth inside the bag filter device.

[0002]

[Prior art]

 7 and 8 show a schematic structure around a venturi tube of a pulse jet type bag filter device that has been conventionally used, FIG. 7 shows a filtering operation, and FIG. 8 (a) shows a removing operation. FIG. 8 (b) shows the pressure distribution in the filter cloth during the removal work.

In FIG. 7, a is a filter chamber of the bag filter device, and the plurality of filter cloths b suspended in the filter chamber are composed of a plurality of vertical members and an annular member connecting the vertical members. It is supported from the inside by a cage-shaped retainer r.

The upper end of the filter cloth b is folded back through the flexible snap ring c and then crimped to the collar e mounted on the stopper fitting d by the outward extension force of the snap ring c. Is held by.

A venturi tube u is attached to an upper portion of a cylindrical filter body composed of a filter cloth b and a retainer r so as to cover the outer periphery of the upper portion of the filter body with a fastener metal d and a collar e. In the clean gas passage f above the venturi pipe u, a nozzle n for injecting the pulse jet air j during the cleaning operation shown in FIG. 8A is arranged.

The exhaust gas g containing dust and acidic harmful gas introduced into the filtration chamber a is dust-filtered by an adhesion layer containing a neutralizing agent formed on the surface of the filter cloth b, so that the acid harmful gas The gas is neutralized and deposited on the surface of the adhering layer to form a dust layer h, and the exhaust gas g passing through the dust layer h and the adhering layer and the filter cloth b becomes a clean gas k, which is cleaned via the Venturi tube u. The gas enters the gas passage f, is sucked by an unillustrated draft fan, and is discharged from the chimney to the outside (see FIG. 7).

When the layer thickness of the dust layer h that accumulates increases as the filtration work continues, the ventilation resistance of the exhaust gas g increases and the load on the induction fan (not shown) increases. When the jet air j is jetted for a short time, the pulse jet air j penetrates the venturi tube u to reach the tip of the filter cloth b and impacts the dust layer h to be released from the filter cloth b, and at the same time, the clean gas passage A large amount of the clean gas k in f is attracted as a secondary fluid, which also rushes into the inside of the filter cloth b via the Venturi tube u, and sends air to the dust layer h from the inner surface to separate the dust, and thus the dust is discharged. The layer h is removed [see FIG. 8 (a)]. As shown in FIG. 8B, the pressure distribution of the secondary fluid k acting on the upper part of the filter cloth b at the time of this removal is negative in the part where the venturi tube u is located, and is in the part below this. A predetermined pressure will act.

Then, when the cleaning operation is finished, the exhaust gas g returns to the normal filtration operation in which the exhaust gas g passes through the adhering layer remaining on the surface of the filter cloth b and the filter cloth b again.

[0009]

[Problems to be solved by the device]

 However, in the case where the venturi tube u is closely attached to the inlet of the filter cloth b like the above-mentioned conventional pulse jet type bag filter device, the dust layer h and the adhering layer and the filter cloth b are filtered and neutralized. Since all the clean gas k passes through the venturi pipe u, pressure loss due to contraction and diffusion of the clean gas k in the part of the venturi pipe u increases during normal filtration work. The load on the suction fan that sucked in was heavy.

Further, since the entire amount of the secondary fluid k attracted by the pulse jet air flow j at the time of brushing off also passes through the venturi tube u, not only the pressure is lost for the same reason as described above, but As shown in FIGS. 8 (a) and 8 (b), since the secondary fluid k does not flow back to the upper part of the filter cloth b located at the back of the Venturi tube u, the dust layer h cannot be wiped off and the upper part is not removed. The dust layer h of No. 2 remained and adhered to the surface of the filter cloth b, resulting in narrowing the filtration area.

[0011]

[Means for Solving the Problems]

 In the venturi tube mounting structure of the bag filter device of the present invention, the filter chamber and the clean gas passage are separated by a partition plate having a filter cloth, and the filter chamber and the clean gas passage are provided on the filter cloth and the upper portion of the filter cloth. In the bag filter device communicated through the venturi pipe, the venturi pipe is provided in the partition plate with a void in the peripheral portion, and the inside of the filter cloth and the clean gas passage are provided in the void and the venturi pipe. It was communicated through.

[0012]

[Action]

 By connecting the inside of the filter cloth and the clean gas passage through the gap and the venturi pipe, during the filtering operation, the clean gas that has passed through the filter cloth passes through the gap as well as the venturi pipe and the clean gas. Since it flows into the passage, the passage is enlarged compared to the conventional one that only passes through the Venturi pipe. Further, even when the cleaning operation is performed, the gas in the clean gas passage will flow into the filter cloth through the venturi pipe and the void, so that the ventilation resistance is significantly reduced and the cleaning efficiency is improved.

[0013]

【Example】

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

1 and 2 show a schematic structure of a venturi pipe mounting structure of a bag filter device according to the present invention, FIG. 3 shows a state during filtration work, and FIG. 4 (a) shows a state during removal work. FIG. 4 (b) shows the pressure distribution acting on the upper part of the filter cloth at the time of the scraping work.

1 and 2, reference numeral 1 denotes a part of a filter chamber in the bag filter device, which is separated from an upper clean gas passage 4 by a partition plate 3 suspending a plurality of filter cloths 2.

The filter cloth 2 has a retainer 5 interposed therein to withstand the gas flow pressure during the filtering operation. The retainer 5 is constructed in a cage shape by a plurality of vertical members 51 made of a rigid material and an annular member 52 which is also made of a rigid material and connects the vertical members 51.

The upper end of the filter cloth 2 is folded back via the snap ring 6 having flexibility, and the tip of the folded portion is provided with a collar 31 provided on the partition plate 3 by the extension force of the snap ring 6. The filter cloth 2 is suspended in the filtration chamber 1 by being pressure-bonded to.

A Venturi tube 7 is fixed to the center of the upper portion of the retainer 5. The venturi pipe 7 is for guiding a pulse jet air 91 described later, and an appropriate number (three in this example) of support plates 71 are spaced at appropriate intervals at the upper end of the venturi pipe 7. The support plate 71 is extended in a radial direction, and the support plate 71 is held by a screw member 33 between a stopper 32 and a collar 31 provided on the partition plate 3, so that the venturi pipe 7 and the retainer 5 are held by the partition plate 3. Is provided in the opening.

By providing the Venturi tube 7 in the opening of the partition plate 3 with the support plate 71 having such a space, a void 8 is formed around the Venturi tube 7.

Further, in the clean gas passage 4 above the venturi pipe 7, a nozzle 9 for injecting pulse jet air 91, which will be described later, is arranged at a position facing the venturi pipe 7.

Next, the flow of the exhaust gas, the clean gas, and the pulse jet air during the filtering work and the cleaning work in the venturi pipe mounting structure of the bag filter device according to the present invention configured as described above will be described.

First, at the time of filtration operation, as shown in FIG. 3, the exhaust gas 10 containing dust and acidic harmful gas introduced into the filtration chamber 1 is previously formed on the surface of the filter cloth 2 by a neutralizing agent. It passes through the precoat layer 21 and the filter cloth 2.

At that time, the dust contained in the exhaust gas 10 is filtered on the surface of the precoat layer 21 and accumulated to form the dust layer 22, and the acidic harmful gas also contained therein is neutralized by the chemical agent in the precoat layer 21. After passing through the precoat layer 21, it becomes the clean gas 11, rises in the filter body composed of the filter cloth 2 and the retainer 5, passes through the venturi pipe 7 and the void 8 and enters the clean gas passage 4, and Not attracted to the draft fan and discharged from the chimney to the outside.

As described above, the clean gas 11 passes through the void 8 as well as the venturi pipe 7, so that the passage is enlarged as compared with the conventional one that passes only the venturi pipe 7, and the clean gas 11 shrinks. The pressure loss due to flow and diffusion is almost eliminated, and the load on the induction fan is reduced.

Then, when the above-described filtration work is continued, the dust layer 22 that accumulates gradually grows, the ventilation resistance of the exhaust gas 10 increases, and the load of the attracting fan (not shown) increases, so that the dust layer 22 of the dust layer 22 increases. Make a payment.

As shown in FIG. 4 (a), in the cleaning operation, high pressure air from a compressed air source (not shown) is jetted from the nozzle 9 for a short time. The pulse jet air 91 thus jetted passes through the venturi tube 7 and reaches the tip of the filter cloth 2, and the impact thereof releases the dust layer 22 and the precoat layer 21 from the filter cloth 2, and at the same time, cleans them. A large amount of the clean gas 11 in the clean gas passage 4 is attracted into the filter cloth 2 as a secondary fluid.

The flow of the clean gas 11 does not converge and flow through the Venturi tube 7 as in the conventional structure, but also passes through the voids 8 and therefore flows backward into the filter cloth 2 with a low ventilation resistance. Thus, the released dust layer 22 and the precoat layer 21 can be efficiently peeled from the filter cloth 2.

At this time, the pressure distribution on the inner surface of the filter cloth 2 due to the secondary fluid 11 in the upper part of the filter cloth 2 has a tendency shown in FIG. 4B, and the dust layer 22 is evenly removed, and the filtration area can be effectively used. .

When the cleaning operation is completed, a new precoat layer 21 is formed on the filter cloth 2 and then the exhaust gas 10 is circulated to restart the normal filtering operation.

In this example, the precoat layer 21 formed on the surface of the filter cloth 2 has been described as performing the filtration and neutralization work, but the precoat layer 21 is not formed in advance and the neutralizing agent is discharged. It is also possible to continuously inject into the gas 10 and perform filtration and neutralization work on the accumulated dust layer.

FIG. 5 shows another embodiment of the Venturi tube mounting structure of the bag filter device according to the present invention.

In the Venturi tube mounting structure, the retainer 5 is fixed to the upper portion of the retainer 5, and the retainer 35 is placed on the upper surface of the opening peripheral edge of the partition plate 3, so that the upper end of the retainer 5 is inside the clean gas passage 4. It is arranged above the partition plate 3 so as to project to the above, the venturi pipe 7 is supported on the upper portion of the retainer 5, and the gap 8 is further enlarged. The other structure is the same as that of the above embodiment, and the same members are denoted by the same reference numerals and the description thereof is omitted.

FIG. 6 shows still another embodiment of the Venturi tube mounting structure of the bag filter device according to the present invention, in which the upper end of the retainer 5 has the clean gas passage 4 as in the case shown in FIG. The stopper fitting 35 fixed to the retainer 5 and arranged above the partition plate 3 so as to project inward is fixed to the partition plate 3 with a screw member 36, and the venturi pipe 7 is attached to the upper portion of the retainer 5. I supported it.

The flow of exhaust gas, clean gas, pulse jet air, etc. during the filtering work and the removing work in the Venturi tube mounting structure shown in FIGS. 5 and 6 are the same as those in the above-mentioned embodiment, and will be described. Is omitted.

The heights of the Venturi tube 7 and the retainer 5 with respect to the partition plate 3 may be adjustable by an adjusting screw or the like (not shown).

[0036]

[Effect of device]

 As described above, according to the present invention, since the inside of the filter cloth and the clean gas passage are communicated with each other through the gap and the venturi pipe, during the filtering operation, the clean gas passing through the filter cloth is prevented. In addition to the venturi pipe, the gas also passes through the voids and flows into the clean gas passage, and the passage is enlarged compared to the conventional one that passes only the venturi pipe, and the pressure due to the contraction and diffusion of the clean gas is increased. The loss is almost eliminated and the burden of the induced draft fan is reduced. In addition, even during the cleaning operation, the gas in the clean gas passage will flow back into the filter cloth through the venturi tube and the void, which significantly reduces the ventilation resistance and improves the cleaning efficiency. The dust layer can be wiped off even on the upper part of the filter cloth where the Venturi tube is located, and the filtration area can be effectively utilized.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a Venturi tube mounting structure of a bag filter device according to the present invention.

FIG. 2 is a plan view showing a schematic configuration of a Venturi tube mounting structure of the bag filter device according to the present invention.

FIG. 3 is an explanatory view showing a state of a bag filter device according to the present invention at the time of filtering work by the Venturi tube mounting structure.

FIG. 4 (a) is an explanatory view showing a state of the bag filter device according to the present invention at the time of removing work by the venturi pipe mounting structure, and FIG. 4 (b) is an upper part in the filter cloth at the time of removing work. It is a figure which shows the pressure distribution which acts on.

FIG. 5 is a cross-sectional view showing another embodiment of the Venturi tube mounting structure of the bag filter device according to the present invention.

FIG. 6 is a cross-sectional view showing another embodiment of the Venturi tube mounting structure of the bag filter device according to the present invention.

FIG. 7 is a diagram showing a state during a filtering operation in the venturi pipe mounting structure of the conventional bag filter device.

FIG. 8 (a) is a diagram showing a state of a venturi tube mounting structure of a conventional bag filter device during a scraping operation, and FIG. 8 (b) acts on an upper part of a filter cloth during the scraping operation. It is a figure which shows pressure distribution.

[Explanation of symbols]

 1 Filter Chamber 2 Filter Cloth 3 Partition Plate 4 Clean Gas Passage 7 Venturi Tube 8 Void

Claims (1)

[Scope of utility model registration request] 1. A bag in which a filter chamber and a clean gas passage are separated by a partition plate having a filter cloth, and the filter chamber and the clean gas passage are communicated with each other through a filter cloth and a venturi pipe provided on the filter cloth. In the filter device, the venturi pipe is provided in the partition plate with a void in a peripheral portion thereof, and the inside of the filter cloth and the clean gas passage are communicated with each other through the void and the venturi pipe. Venturi tube mounting structure for bag filter device.