JPH0332716A - Method and device for backwashing dust collector - Google Patents

Abstract

PURPOSE:To prevent the clogging of a bottomed cylindrical ceramic filter even though the dust collector is continuously operated for a long time by selectively injecting a gas into the hollow part of the filter and successively scattering and removing the dust from the plural filters. CONSTITUTION:A filter supporting member 17 having plural through holes 16 is set in a shell 15, and the inside of the shell 15 is divided into a waste gas inlet chamber 18 and a waste gas discharge chamber 19. The bottomed cylindrical ceramic filter 20 is inserted into each of the plural through holes 16 and fixed, the opening 21 of the filter 20 is positioned on the discharge chamber 19 side, and the dust in the waste gas introduced into the inlet chamber 18 is removed by the filter 20. The waste gas passed through the filter 20 is discharged from the discharge chamber 19, a gas is injected into the hollow part 20a in the filter 20 from the opening 21 by a gas injection means 23 provided in the discharge chamber 19, and the dust depositing on the filter 20 is scattered and removed. In this case, the gas is selectively injected into the hollow part 20a, and the plural filters are successively freed of dust.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a dust remover for removing dust contained in exhaust gas, particularly high-temperature exhaust gas, and uses compressed gas backwash injection to remove dust accumulated on a ceramic filter. The present invention relates to a method for backwashing a dust removing machine and an apparatus therefor.

(Prior Art) When incinerating radioactive waste at a nuclear power plant or the like, it is necessary to efficiently capture and remove dust in high-temperature exhaust gas. In particular, when incinerating hazardous substances and pollutants such as radioactive waste, special consideration is required to prevent radioactive dust from leaking outside.

FIG. 3 is a schematic diagram showing a dust remover for high-temperature exhaust gas after incineration treatment.

It has an exhaust gas inlet 10 on the lower side wall, an exhaust gas outlet 11 on the upper side wall, and a dust extraction hole 2 on the bottom.
The inner surface of the sealed container 13 made of a steel plate or the like having
4 to form a can body 15.

A filter support plate 17 made of heat-resistant steel or refractory material, preferably having a convex curved surface on the high temperature side and having a large number of through holes 16, is provided in the can body 15.
5 is divided into an exhaust gas introduction chamber 18 into which an exhaust gas introduction port 10 opens, and an exhaust gas discharge chamber 19 into which an exhaust gas discharge port 11 opens.

A large number of through holes 16 in the filter support board 17 are provided.
Inside is a bottomed cylindrical porous ceramic filter 20.
is inserted and suspended in the exhaust gas introduction chamber 18.

In this case, it is preferable that an annular enlarged part 22 is provided on the outer periphery of the open end 21 of the ceramic filter 20 and that the annular enlarged part 22 is kept airtight by contacting the filter support plate 17. A backwash air injection nozzle 23 is provided in the exhaust gas discharge chamber 19 above the opening Dm21 of each ceramic filter 20, and the backwash air injection nozzle 23 opens toward the cylindrical cavity 20a of each ceramic filter 20. The air supply conduit 24 is connected to a compressed air supply device 25 that supplies compressed air to the backwash air injection nozzle 23 .

The can body 15 is kept airtight by a separate lid body 26. For example, high-temperature combustion exhaust gas is transferred to exhaust gas inlet 1.
0 into the exhaust gas introduction chamber 18 as shown by arrow A, the gas flow passes through the pores of a large number of ceramic filters 20 suspended by the filter support board 17, and the dust etc. contained in the exhaust gas is removed from the ceramic filter. The clean high-temperature exhaust gas from which dust and other substances have been removed by the filter 20 is
The gas enters the exhaust gas discharge chamber 19 from the cylindrical cavity 20a of the ceramic filter 20 through the open end 21, and is discharged from the exhaust gas discharge port 11 as shown by arrow B.

And, due to long-term operation, the ceramic filter 20
When dust accumulates on the surface of the cylinder, the compressed air supply device 25 supplies compressed air to the backwash air injection nozzle 23 through the air supply conduit 24, and the compressed air is impulsively injected into the cylindrical cavity 20a. Then, ceramic filter 20
Dust and the like accumulated on the outer surface of the filter are blown off and scattered by compressed air, fall downward, and are taken out from the dust outlet 12.

(Problems to be Solved by the Invention) However, in such a dust remover, when the incinerator is continuously operated, the combustion exhaust gas is continuously supplied into the can body 15. Therefore, if dust is removed from the ceramic filter 20 at the same time during operation, the exhaust gas treatment will stop and the pressure in the exhaust gas introduction chamber 18 will temporarily increase significantly, which is inconvenient, and the operation will be temporarily stopped. The machine is stopped and dust is removed. In particular, when removing dust from the combustion exhaust gas of radioactive waste and other hazardous substances, it is necessary to reduce the pressure inside the incinerator and the can to maintain a negative pressure relative to the atmosphere to prevent harmful substances from leaking outside the can. . In this case - at times a large number of ceramic filters 2
If compressed air is blown out from zero, the pressure will rise rapidly in a short period of time, making it impossible to maintain negative pressure, which is inconvenient.

An object of the present invention is to provide a method and device for backwashing a dust remover, which can remove dust accumulated on a bottomed cylindrical ceramic filter at any time during operation and improve dust treatment efficiency.

(Means for Solving the Problems) The present invention includes a filter support member having a plurality of through holes attached to a can body, the can body being divided into an exhaust gas introduction chamber and an exhaust gas discharge chamber, and a filter support member having a plurality of through holes. A bottomed cylindrical ceramic filter is inserted and fixed into each of the bottomed cylindrical ceramic filters, and the opening of the bottomed cylindrical ceramic filter is located on the exhaust gas discharge chamber side, so that dust in the exhaust gas introduced into the exhaust gas introduction chamber is removed from the bottomed cylindrical ceramic filter. The exhaust gas that has been removed by the ceramic filter and passed through the bottomed cylindrical ceramic filter is discharged from the exhaust gas discharge chamber, and is sent to the bottomed tube through the opening by a gas injection means provided in the exhaust gas discharge chamber. In a method for backwashing a dust remover, the method includes injecting gas into a hollow part of a cylinder of a bottomed cylindrical ceramic filter to scatter and remove the dust deposited on the bottomed cylindrical ceramic filter. The present invention relates to a method for backwashing a dust remover, characterized in that the scattering removal process of a plurality of the bottomed cylindrical ceramic filters is sequentially performed by selectively injecting the same.

The present invention also provides a can body; a filter support member that is attached to the can body and divides the can body into an exhaust gas introduction chamber and an exhaust gas discharge chamber; A bottomed bottom that is inserted and fixed, the opening side is located on the exhaust gas discharge chamber side, and that removes dust from the exhaust gas introduced into the exhaust gas introduction chamber and discharges the passed exhaust gas to the exhaust gas discharge chamber through the opening. A cylindrical ceramic filter; provided in the exhaust gas discharge chamber and having a gas injection port facing the cylinder hollow part of the bottomed cylindrical ceramic filter, and from the gas injection port through the opening, the cylinder hollow part is In a backwashing device for a dust remover, the device includes a gas injection means for injecting gas to a part of the dust remover, a gas supply means for supplying the gas to the gas injection means via a gas conduction path; provided in the gas conduction path; and a valve member that selectively supplies and shuts off the gas for each of the gas injection means or for each of a plurality of the gas injection means via the gas conduction path. This relates to washing equipment.

(Example) FIG. 1 is a schematic diagram showing a dust remover with a backwashing device according to the present example. Functional members that are the same as those in the device shown in FIG. 3 are given the same reference numerals, and their explanations will be omitted.

A characteristic feature of this example is that the air conduction pipe 8 connected to each injection nozzle 23 is provided with a solenoid valve 1 for each injection nozzle 23, respectively. Then, a solenoid valve 5 is provided between the compressed air supply pump 30 and the compressed air tank 2,
A solenoid valve 4 is also provided between the small capacity compressed air tank 2 and the large capacity compressed air tank 3. Further, a solenoid valve 6 is also provided between the compressed air supply pump 30 and the air passage pipe at the outlet of the compressed air tank 2.

Then, while supplying exhaust gas from an incinerator (not shown) into the exhaust gas supply chamber 18, the solenoid valve 5 is opened and air is sent from the compressed air supply pump 30 to the compressed air tank 2 as shown by the arrow. At this time, the solenoid valves 4, 1, and 7 are closed to cut off air.

Next, for example, only the electromagnetic valve 1 of the air conduction pipe 8 at the left end provided above the opening of the ceramic filter 20 at the left end in the drawing is opened, and the air in the small capacity compressed air tank 2 is injected from the air injection port 23a. (For example, 5kg/c
m" xlON), the dust on the ceramic filter 20 is scattered and removed. Next, the solenoid valve 1 is closed to shut off the air, and the compressed air is stored again in the compressed air tank 2.
In the drawing, the solenoid valve 1 of the air conduction pipe 8 connected to the second injection nozzle 23 from the left end is opened to scatter and remove dust from the ceramic filter 20 second from the left end. Next, the same process is performed for the third ceramic filter 20 from the left end. In this way, the corresponding solenoid valve l is sequentially or successively opened and closed for each ceramic filter 20.
Dust is scattered and removed every 0.

After scattering and removing dust from each ceramic filter 20, the solenoid valve 7 and all the solenoid valves 1 are opened.

The solenoid valve 5 is closed. Then, a small amount of air is sent in as shown by arrow E through the solenoid valve 7 and the flow rate adjustment needle valve 6, and the air is sent into the cylindrical opening 20a of all the ceramic filters 20 through each solenoid valve 1. The amount of air passing through is regulated by a flow rate regulating needle valve 6 to a very small amount (for example, 0.1 bottles/hour).

Also, close the solenoid valves 7 and 1, open the solenoid valves 5 and 4, and send compressed air into the large capacity compressed air tank 3 as shown by arrow H, and close the solenoid valve 5 to store the compressed air. do.

Next, when the incinerator is stopped, either the solenoid valve 4 or the solenoid valve 1 is opened, while the solenoid valves 5 and 7 are closed.
Compressed air is injected into the cylindrical hollow part 2Oa of the ceramic filter 20 (for example, 5 kg/c+n"
(0ffi) performs more effective scattering removal of dust.

The device of this example can achieve the following effects.

(a) Air is stored in a compressed air tank 2, and dust is removed by scattering from each ceramic filter 20 in sequence. Therefore, unlike injecting compressed air into all ceramic filters 20 at the same time, compressed air is injected into each filter separately, so the pressure inside the exhaust gas introduction chamber 18 does not increase much, which affects the flow of exhaust gas. Dust removal from the exhaust gas can be continued without any hindrance through the other ceramic filter 20. Therefore, the dust removal from the ceramic filters 20 can be performed successively while the operation continues, so the dust removal efficiency of each ceramic filter 20 can be maintained well even during the operation, and the ceramic filters 20 will not be clogged even if the operation continues for a long time. can be prevented.

In particular, when incinerating hazardous substances such as radioactive waste, the can body 1
In this example, compressed air is stored in the small capacity air tank 2, and this air is passed through the ceramic filter 1.
Since it is only injected for each cylinder or several cylinders (see Figure 2 below), there is no risk of the pressure inside the can body 15 rising and harmful substances leaking outside, and there is no risk of the combustion exhaust gas being injected. will not be temporarily interrupted.

(b) During normal operation, a small amount of air is simultaneously flowed into each ceramic filter 20 through the flow rate regulating needle valve 6. Since each backwash air injection nozzle heated by the combustion exhaust gas is appropriately cooled by this small amount of air, the risk of the air conduction pipe 8 etc. outside the can body 15 being heated by heat transfer and causing burns to the worker is prevented. can do.

(C) In radioactive waste incinerators, etc., when the operation is stopped, the introduction of exhaust gas is stopped, so for example -1ooOmm
Negative pressure on the order of Ag can be obtained. However, in conventional backwashing equipment as shown in Figure 3, air is injected from all air injection nozzles at once, so if you try to increase the purge effect by increasing the amount of air per nozzle, the overall The amount of air injection becomes extremely large, and the pressure inside the can body 15 becomes positive, causing harmful substances such as radioactive waste to leak to the outside, making effective purging difficult even when the operation is stopped. Ta.

In contrast, in this example, the incinerator is stopped and the negative pressure inside the can body 15 is maintained higher than during operation, while each air injection nozzle (as shown in Fig. 2 described later) is In the example, a large volume of compressed air is supplied to every 4th cylinder, so
The amount of air ejected from each air injection nozzle is much larger than before, and the dust removal effect is dramatically increased.

Moreover, since backwashing is performed for each air injection nozzle or every several air injection nozzles, the amount of compressed air injected at the time of - can be kept within an appropriate range as a whole, and the pressure inside the can body 15 can be maintained at a positive pressure. This was not the case at all, and efficient backwashing became possible even when the plant was stopped.

As mentioned above, the filter support plate 17 has a convexly curved surface on the high temperature side, that is, on the exhaust gas introduction chamber 18 side, so that extremely good results can be obtained against repeated thermal expansion and contraction. It is preferable that the higher the temperature, the more convexly curved the shape.

In the above example, one solenoid valve was provided for each air injection nozzle, but as shown in Figure 2, a total of four air injection nozzles 23 are connected to one solenoid valve, and simultaneously Compressed air may be supplied from a small-capacity compressed air tank to the four air injection nozzles 23, and dust particles may be removed from the ceramic filters for every four air injection nozzles 23. Of course, the number of air injection nozzles connected to the - solenoid valves may be further varied.

The embodiments described above can be modified in various ways.

In FIG. 1, when the bottomed cylindrical ceraminota filter is held airtight by the filter support i17, it is desirable to interpose a sealing material such as asbestos between the annular enlarged portion 22 and the filter support plate 17.

Air supply conduit 8 to which each backwash air injection nozzle 23 is connected
is installed outside the can body 15 in FIG.
Of course, it may be installed inside the can body 15.

In the example of FIG. 1, the dust is removed by scattering in order from the ceramic filter 20 at the left end in the drawing, but the order in which the dust is removed by scattering can be changed arbitrarily.

The injection gas does not have to be air.

The present invention can be applied to removing dust from high-temperature combustion exhaust gas and dry exhaust gas discharged from incinerators of nuclear power plants, incinerators for treating various types of dust and harmful substances, dryers, and the like.

(Effects of the Invention) According to the method for backwashing a dust remover according to the present invention, gas is selectively injected into the hollow part of the cylinder, and dust attached to a plurality of bottomed cylindrical ceramic filters is scattered and removed. Because this process is carried out sequentially, unlike the process of removing dust from all bottomed cylindrical ceramic filters at the same time, the pressure inside the exhaust gas introduction chamber does not rise suddenly, and the flow of exhaust gas is not affected. Dust removal from the exhaust gas can be continued through the bottomed cylindrical ceramic filter, which does not inject gas into the hollow part of the cylinder. Therefore, dust removal from the bottomed cylindrical ceramic filter is performed successively even during continued operation, and dust removal efficiency can be maintained well, and clogging of the bottomed cylindrical ceramic filter can be prevented even during long-term continuous operation.

According to the backwashing device for a dust remover according to the present invention, the gas supply means supplies gas to the gas injection means through the gas conduction path, and the valve member provided in the gas conduction path allows one gas injection to be performed. Since gas supply and cutoff are selected for each means or for each of a plurality of gas injection means, gas can be selectively supplied to the hollow part of one or more bottomed cylindrical ceramic or tank filters. Since it can be sprayed, it is most suitable for the method of the present invention.

[Brief explanation of drawings]

Fig. 1 is a schematic partial sectional view of a dust remover with a backwashing device, Fig. 2 is an enlarged partial sectional view of main parts showing another backwashing device, and Fig. 3 is a schematic part showing a conventional dust remover with a backwashing device. FIG. 1, 4.5.7...Solenoid valve 2...Small capacity compressed air tank 3...Large capacity compressed air tank 6...Flow rate adjustment needle valve 8...Gas conduction pipe 15...Can Body 18...
Exhaust gas introduction chamber 19...Exhaust gas discharge chamber 20...
Bottomed cylindrical ceramic filter 20a... Cylindrical cavity 21... Opening 23... Gas injection nozzle 2
3a...Gas injection port 30...Gas supply pump Fig. 2

Claims (1)

[Scope of Claims] 1. A filter support member having a plurality of through holes is installed in a can body to divide the can body into an exhaust gas introduction chamber and an exhaust gas discharge chamber, and each of the plurality of through holes has a bottom. A cylindrical ceramic filter is inserted and fixed, the opening of the bottomed cylindrical ceramic filter is located on the exhaust gas discharge chamber side, and the dust in the exhaust gas introduced into the exhaust gas introduction chamber is removed by the bottomed cylindrical ceramic filter. The exhaust gas that has passed through the bottomed cylindrical ceramic filter is discharged from the exhaust gas discharge chamber, and the exhaust gas is discharged from the hollow inside of the bottomed cylindrical ceramic filter through the opening from a gas injection means provided in the exhaust gas discharge chamber. In a method for backwashing a dust remover, the method comprises: selectively injecting the gas into the hollow part of the cylinder; A method for backwashing a dust remover, comprising sequentially performing the scattering removal process on a plurality of bottomed cylindrical ceramic filters. 2. a can body; a filter support member that is attached to the can body and divides the can body into an exhaust gas introduction chamber and an exhaust gas discharge chamber; inserted and fixed into each of the plurality of through holes of the filter support member; a bottomed cylindrical ceramic filter whose opening side is located on the exhaust gas discharge chamber side, and which removes dust in the exhaust gas introduced into the exhaust gas introduction chamber and discharges the passed exhaust gas to the exhaust gas discharge chamber through the opening; and; a gas injection port is provided in the exhaust gas discharge chamber and faces the cylinder hollow part of the bottomed cylindrical ceramic filter, and gas is injected from the gas injection port into the cylinder hollow part through the opening. A backwashing device for a dust remover, comprising: a gas supply means for supplying the gas to the gas injection means via a gas conduction path; A backwashing device for a dust remover, comprising a valve member that selectively supplies and shuts off the gas for each of the gas injection means or for each of a plurality of the gas injection means via a passage.