JP3294021B2 - Freestanding bag filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free-standing bag filter having a backwash mechanism for a filter element.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show the structure of a bag filter according to the prior art and the backwashing mechanism of the filter element.
Will be described. In the bag filter shown in FIGS. 4 and 5, 3a is a filter element, 4a is a gas inlet pipe, 7
a is a dust outlet, 8a is a rotary valve, 9a is a gas outlet opening / closing valve, and 10a is a gas outlet pipe. The backwashing device for the filter element 3a includes an air tank 11a and an on-off valve 12a for backwashing air. 5a is a clean gas, 6a is solid particles, and 13a is backwash air.

Next, the operation will be described. A gas 5a containing solid particles 6a is introduced into the apparatus from the gas inlet pipe 4a of the bag filter. The solid particles 6a are collected on the surface when passing through the filter element 3a,
Only the gas is discharged from the gas outlet pipe 10a to the outside.

[0004] The collected solid particles 6a adhere to the surface of the filter element 3a or fall to the lower part of the hopper,
Pushed out by the rotary valve 8a, the dust outlet 7
collected from a. When the filter element 3a becomes clogged, it is necessary to perform cleaning to remove the clogging, and this operation is called backwashing.

[0005] Compressed air produced by a compressor (not shown) is held in the air tank 11a when the bag filter is operated, and the backwash air valve 1 is used when the filter element 3a is backwashed.
2a is opened, and the air is flown from the inside of the filter element 3a to remove the solid particles 6a on the surface of the filter element 3a to eliminate clogging of the filter element 3a.

[0006]

As described above, the conventional bag filter has a separate air source for backwashing as described above.
Compressed air production equipment for backwashing is required, and its power is also required. Further, there is a drawback that the apparatus becomes complicated, such as providing a backwash air supply piping.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a self-contained bag filter which does not require an external compressed air system for backwashing a filter in a bag filter having a built-in filter element.

[0008]

SUMMARY OF THE INVENTION The present invention employs the following structure in order to solve the above-mentioned problems in a bag filter having a built-in filter element for removing solid particles contained in exhaust gas. First, the bag filter is composed of at least two sets of bag filters. For this purpose, for example, the inside of the bag filter is divided by a partition plate into two or more filters having an integral structure, or two or more independent bag filters are used.

Then, a piping system for supplying exhaust gas to each of the bag filters and a piping system for exhausting gas cleaned by the bag filters are provided. Also,
An ejector that is provided in the exhaust piping system and is operated by the gas cleaned by the bag filter, and a piping system that supplies the gas cleaned by one of the bag filters to another bag filter and backwashes the same. Provide.

[0010]

The operation of the self-standing bag filter according to the present invention, constructed as described above, is as follows. For the sake of simplicity, a description will be given below of a case where the configuration is made up of two sets of bag filters. By switching the common valve of the two sets of bag filters divided into two chambers or two bag filters and switching valves provided at the respective outlets, one bag filter is activated and the other bag filter is activated. Put into hibernation.

The outlet of the active bag filter is connected to the nozzle of the ejector to activate the ejector, while the outlet of the bag filter at rest is connected to the decompression chamber of the ejector. In this state, the pressure in the active bag filter is high, and the pressure in the inactive bag filter is negative.

When the on-off valve at the ejector outlet is closed (or sometimes kept open) with the internal pressure of the inactive bag filter lowered as described above, and the bag filters are communicated with each other, the difference between the bag filters is reduced. Due to the pressure, the clean gas instantaneously flows into the inactive bag filter from the active bag filter, and the gas flows from inside to outside of the inactive filter element. By this flow, so-called backwashing is performed, in which solid particles and clogging particles on the outer periphery of the rest-side filter element are removed by a sudden blowing of clean gas.

When the backwashing is completed in this way, the valves and the like of each piping system are switched so that exhaust gas is also sent to the paused bag filter, and both bag filters are activated. In this way, the bag filter is backwashed as necessary or periodically.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A self-standing bag filter according to the present invention will be specifically described below with reference to the embodiments shown in FIGS. FIG.
3 to 3, the illustrated bag filter has a single casing and is internally partitioned into a chamber A and a chamber B to form an integral structure.
There are two bug filters. Although not shown, 1
There may be at least two or more sets of independent bag filters without dividing one casing into two.

First, the structure of the present bag filter will be described with reference to FIG. Separation and collection chamber for solid particles
Room and room B. Gas inlet pipe 4 is inlet three-way valve 2
Are connected to the room A and the room B. The outlet pipes of the chambers A and B are connected to a switching three-way valve 14 at the outlet of the chamber A and a switching three-way valve 15 at the outlet of the chamber B, respectively.

An ejector 16 is provided after the switching type three-way valves 14 and 15, and is connected to the nozzle 16 a of the ejector 16 and the pressure reducing chamber 16 b from the switching type three-way valves 14 and 15. One is ejector 1
The three-way valves 14 and 15 are switched so as to communicate with the nozzle 16a of No. 6 and the other with the pressure reducing chamber 16b. An on-off valve 17 is provided at the outlet of the ejector 16 and is connected to the gas outlet pipe 10. In front of the switching three-way valves 14 and 15, the respective outlet pipes are connected with an on-off valve 18 provided therebetween.

FIGS. 2 and 3 have the same structure as that of the apparatus of FIG. 1 described above, except that the operation of the A and B chambers is changed by switching the communication of the piping system connecting the A and B chambers. It is. That is, FIG. 1 shows the filtration state of the chamber A and the decompression state of the chamber B, and FIG.
FIG. 3 shows a state in which the on-off valve 17 is closed and the A-room filtration and the B-room are backwashed, and FIG.

In FIG. 1 to FIG. 3, the open / closed valves are open and those painted black are closed, and the thick arrows of the three-way switching valve indicate the gas flow direction. I have.

Next, the operation of the bag filter according to this embodiment will be described with reference to FIGS. As shown in FIG.
The chamber is filtering the exhaust gas, and the chamber B communicates with the decompression chamber 16 b of the ejector 16. From this state, the backwashing of the filter element 3 in the chamber B is started. As shown in FIG. 2, the on-off valve 17 installed at the outlet of the ejector 16 is closed, and the on-off valve 18 in the connecting pipe connecting the chambers A and B is opened. 5 enters the chamber B through the on-off valve 18 and flows from the inside to the outside of the filter element 3;
Solid particles 6 attached to the outside of the filter element 3 in the chamber
a is removed. In this case, the device must be performed in a short time because it is in operation. If it is long, the operation of the device will be hindered.

FIG. 3 shows a case where backwashing is performed by a valve switching different from the valve switching shown in FIG. That is, in the method shown in FIG. 3, the on-off valve 18 in the connecting pipe connecting the chambers A and B is opened while the on-off valve 17 at the outlet of the ejector 16 is kept open. Also in this case, the filter element in the chamber B can be backwashed as in FIG. However, as compared with the case of FIG. 2, there is a disadvantage that the pressure difference between the chamber A and the chamber B is small and the flow rate of the clean gas is small, but the advantage is that one bag filter can be backwashed anytime and any number of times without any trouble in operation. There is.

In the above description, the chamber B is backwashed, but the backwashing of the chamber A can be performed in the same manner by switching the three-way valve at the entrance and exit.

Although the present invention has been described in detail with reference to the illustrated embodiments, the present invention is not limited to these embodiments, but has the specific structure within the scope of the present invention as set forth in the appended claims. It is needless to say that various changes may be made to.

For example, in the above embodiment, a bag filter composed of two sets of bag filters has been described.
The same applies to pairs or more. Further, although a three-way valve is used as the switching valve, the invention is not limited to the three-way valve and can be adopted as long as it switches gas flow.

[0024]

As described above, according to the bag filter of the present invention, unlike a conventional bag filter, a clean gas obtained by filtering solid particles from a supplied gas is used for backwashing. The washing compressed air system can be eliminated, the apparatus can be simplified, and the power for operating the compressed air producing apparatus is not required.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a bag filter according to an embodiment of the present invention.

FIG. 2 is a view showing a state in which one bag filter is being backwashed.
FIG.

FIG. 3 is a configuration diagram similar to FIG. 1, showing a state of a backwashing operation different from that of FIG. 2;

FIG. 4 is a configuration diagram showing a conventional bag filter.

FIG. 5 is an explanatory diagram showing the bag filter of FIG. 4 in a state during backwashing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 partition plate 2 switchable three-way valve 3 filter element 4 gas inlet pipe 5 gas 6 solid particles 7 dust outlet 8 rotary valve 10 gas outlet pipe 14, 15 valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B01D 46/04

Claims (2)

(57) [Claims] 1. A bag filter including a filter element for removing solid particles contained in exhaust gas, wherein the bag filter includes at least two sets of bag filters, and supplies exhaust gas to each of the bag filters. A piping system, a piping system for exhausting gas cleaned by the bag filter, and an ejector provided in the exhaust piping system and operated by the gas cleaned by the bag filter,
A self-standing bag filter, comprising: a piping system for supplying the gas purified by one of the bag filters to another bag filter to backwash the gas. 2. The self-standing bag filter according to claim 1, wherein the bag filter is formed as an integral structure by dividing the inside of one bag filter casing into at least two by a partition wall.