CN115090418A

CN115090418A - Rapping device and electric dust removal and ash conveying system

Info

Publication number: CN115090418A
Application number: CN202210612742.4A
Authority: CN
Inventors: 王伟; 胡伟斌; 刘四海; 丁洁
Original assignee: Zhejiang Ninghai Power Generation Co ltd
Current assignee: Zhejiang Ninghai Power Generation Co ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-09-23
Anticipated expiration: 2042-05-31
Also published as: CN115090418B

Abstract

The utility model relates to a rapping device and defeated grey system of electric precipitation, rapping device includes: the discharging pipe is used for communicating the discharging hopper with the bin pump; the pneumatic vibrator is arranged on the outer wall of the blanking pipe; an air supply flow path communicated with the pneumatic vibrator and providing an air source for the pneumatic vibrator; the linkage control assembly comprises a first normally-open pneumatic valve arranged on the air supply flow path, a dome valve arranged at the bottom end of the blanking pipe and a first control air path for communicating the first normally-open pneumatic valve with a sealing pressure pipe of the dome valve, when the dome valve is closed, the first normally-open pneumatic valve is closed, and the pneumatic vibrator stops vibrating; when the dome valve is opened, the first normally-open pneumatic valve is opened, the pneumatic vibrator starts to vibrate after being inflated, the pneumatic vibrator automatically vibrates and stops along with the opening and closing of the dome valve, and the dome valve and the pneumatic vibrator are linked.

Description

Rapping device and electric dust removal and ash conveying system

Technical Field

The disclosure relates to the technical field of rapping devices, in particular to a rapping device and an electric dust removal and ash conveying system.

Background

The electrostatic precipitator is the necessary corollary equipment of large-scale thermal power plant, and negative pole line corona discharge when its main action flue gas circulation electrostatic precipitator major structure makes the smoke and dust take electric charge, and nuclear power dust granule is adsorbed on the anode plate in the effect of electric field power, regularly shakes the dust on anode plate and the negative pole line through rapping device and reaches and drop to inside the ash bucket, carries the ash to the ash storehouse through the defeated ash system of strength to reach the dust granule in getting rid of the flue gas. The defeated grey system of electrostatic precipitator adopts the air force to send the grey system mostly, with inside ash row warehousing pump of ash bucket, however, when the unit load is high, the grey coal ash is big, ash viscosity will appear the ash bucket when big the ash is not smooth down, need use the vibrator to shake and beat the outer wall of unloading pipe, at present, most use electric vibrator to shake and beat, need newly increase the cable, and insert DCS system increase control logic, therefore, the cost is high, connect complicated, the scene is realized not simply.

Disclosure of Invention

The utility model aims at providing a rapping device and defeated grey system of electrostatic precipitator, this rapping device adopt pneumatic vibrator to carry out the rapping of unloading pipe outer wall, need not to insert a large amount of cables, and the scene is realized getting up simply to pneumatic vibrator produces the linkage with the dome valve of unloading pipe department, and along with opening and close of dome valve, pneumatic vibrator shakes automatically and shakes and stops.

In order to achieve the above object, a first aspect of the present disclosure provides a rapping device comprising: the blanking pipe is communicated between a discharge opening of the blanking hopper and a feed inlet of the bin pump; the pneumatic vibrator is arranged on the outer wall of the blanking pipe; the air supply flow path is communicated with the pneumatic vibrator and is used for providing an air source for the pneumatic vibrator; and the linkage control assembly comprises a first normally-open pneumatic valve arranged on the air supply flow path, a dome valve arranged at the bottom end of the blanking pipe and a first control air path for communicating the first normally-open pneumatic valve with a sealed pressure pipe of the dome valve, and is configured to: when the dome valve is closed, the sealed air source flowing through the sealed pressure pipe flows to the first normally open pneumatic valve through the first control air passage, so that the first normally open pneumatic valve is closed; when the dome valve is open, gas within the first control gas path is vented through the sealed pressure tube to open the first normally open pneumatic valve.

Optionally, a first exhaust flow path for communicating with an external environment is provided on the bin pump, the coordinated control assembly further comprises a second normally open pneumatic valve provided on the first exhaust flow path and a second control gas path communicating the second normally open pneumatic valve and a sealed pressure tube of the dome valve, the coordinated control assembly is further configured to: a seal gas source flow through said seal pressure tube through said second control gas path to said second normally open pneumatic valve to close said second normally open pneumatic valve when said dome valve is closed; when the dome valve is opened, gas in the second control gas path is exhausted through the sealed pressure tube to open the second normally open pneumatic valve.

Optionally, the linkage control assembly comprises a master control gas circuit, the end of the first control gas circuit, which is far away from the first normally-open pneumatic valve, and the end of the second controller, which is far away from the second normally-open pneumatic valve, are both communicated with the sealed pressure pipe of the dome valve through the master control gas circuit, and a first valve is arranged on the master control gas circuit.

Optionally, a second valve is arranged on the first control air passage, and a third valve is arranged on the second control air passage.

Optionally, a fourth valve is disposed on the first exhaust flow path between the bin pump and the second normally open pneumatic valve.

Optionally, a fifth valve is disposed on the air supply flow path.

Optionally, the rapping device further comprises a second exhaust gas flow path communicating the bin pump and the blanking hopper, and a sixth valve is arranged on the second exhaust gas flow path.

Optionally, a stop valve is arranged between the feeding pipe and the feeding hopper.

Optionally, the number of the pneumatic vibrators is multiple, and each pneumatic vibrator is communicated with the air supply flow path.

The second aspect of the disclosure provides an electric dust removal ash conveying system, which comprises an electric dust remover and the rapping device, wherein an ash bucket of the electric dust remover is the discharging hopper.

Through the technical scheme, the blanking pipe is arranged between the discharge port of the blanking hopper and the bin pump, the pneumatic vibrator is arranged on the outer wall of the blanking pipe, the air supply flow path is communicated with the pneumatic vibrator and is used for providing an air source for the pneumatic vibrator, the first normally open pneumatic valve is arranged on the air supply flow path, the dome valve is arranged at the bottom end of the blanking pipe, the sealing pressure pipe of the dome valve is communicated with the first normally open pneumatic valve through the first control air path, when the dome valve is closed, the sealing air source flowing through the sealing pressure pipe flows to the first normally open pneumatic valve through the first control air path so as to close the first normally open pneumatic valve, the air supply flow path does not provide an air source for the pneumatic vibrator any more, the pneumatic vibrator stops rapping, when the dome valve is opened, the air in the first control air path is discharged through the sealing pressure pipe so as to open the first pneumatic valve, and then the air supply flow path provides an air source for the pneumatic vibrator, the pneumatic vibrator begins to vibrate the blanking pipe, can strengthen the mobility of ash, promotes dropping of ash, need not to insert a large amount of cable conductors, and the scene is realized comparatively simply, and pneumatic vibrator produces the linkage with the dome valve of inlet pipe moreover, and along with opening and close of inlet pipe bottom dome valve, makes the automatic vibration of pneumatic vibrator and stops, realizes the linkage between pneumatic vibrator and the original equipment dome valve.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

fig. 1 is a schematic structural diagram of a discharge hopper and a bin pump on an electric dust-collecting ash conveying system and a rapping device installed on the electric dust-collecting ash conveying system provided in an exemplary embodiment of the present disclosure.

Description of the reference numerals

1. A compressed air conduit; 2. a fifth valve; 3. an air supply flow path; 4. a first normally open pneumatic valve; 5. a second valve; 6. a master control gas circuit; 7. a first valve; 8. a pneumatic vibrator; 9. a first control gas path; 10. a third valve; 11. a second control gas path; 12. a second normally open pneumatic valve; 13. a fourth valve; 14. a first exhaust gas flow path; 15. a delivery conduit; 16. a bin pump; 17. a second exhaust gas flow path; 18. a sixth valve; 19. a dome valve; 20. a feeding pipe; 21. a stop valve; 22. and (4) discharging the hopper.

Detailed Description

The following detailed description of the embodiments of the disclosure refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the present disclosure, are given by way of illustration and explanation only, not limitation.

In this disclosure, where the context does not otherwise dictate, directional words such as "inner" and "outer" are used herein to refer to both the inner and outer profile of a component or structure itself. The terms "first," "second," and the like are used to distinguish one element from another, and are not intended to be sequential or important.

As shown in fig. 1, a first aspect of the present disclosure provides a vibration device including: a discharge pipe 20 communicated between a discharge opening of the discharge hopper 22 and a feed opening of the bin pump 16; the pneumatic vibrator 8 is arranged on the outer wall of the blanking pipe 20; the air supply flow path 3 is communicated with the pneumatic vibrator 8 and is used for supplying air to the pneumatic vibrator 8; and a linkage control assembly including a first normally open air-operated valve 4 provided on the air supply flow path 3, a dome valve 19 provided at a bottom end of the blanking pipe 20, and a first control air path 9 communicating the first normally open air-operated valve 4 with a sealed pressure pipe of the dome valve 19, the linkage control assembly being configured to: when the dome valve 19 is closed, the sealed air source flowing through the sealed pressure pipe flows to the first normally open pneumatic valve 4 through the first control air path 9, so that the first normally open pneumatic valve 4 is closed; when the dome valve 19 opens, the gas in the first control circuit 9 is exhausted through the sealed pressure tube to open the first normally open pneumatic valve 4.

The dome valve 19 generally comprises a valve body, a valve core configured as a spherical dome disposed in the valve body, and an inflatable gasket for sealing the valve core when the valve core is in a closed position, wherein when the dome valve 19 is closed, the valve core is rotated to the closed position, a sealing pressure tube supplies air to the gasket to expand the gasket to seal the valve core, and when the dome valve 19 is opened, the sealing pressure tube stops supplying air and removes air pressure. Therefore, the first control air path 9 is communicated with the sealed pressure tube, when the dome valve 19 is closed, the sealed pressure tube can inflate a sealing ring of the dome valve 19, meanwhile, a part of air source flowing through the sealed pressure tube can flow to the first normally-open pneumatic valve 4 through the first control air path 9, the first normally-open pneumatic valve 4 can be driven to be closed by the part of air source, the air supply flow path 3 is cut off to supply air to the pneumatic vibrator 8, and the pneumatic vibrator 8 stops working; conversely, when the dome valve 19 is opened, the air pressure in the seal pressure pipe is removed, so that the air pressure in the first control air passage 9 is simultaneously removed, and at this time, the first normally-open air-operated valve 4 can be restored to the normally-open state.

In the above embodiment, one end of the air supply flow path 3 is communicated with the pneumatic vibrator 8 disposed at the blanking tube 20, the other end of the air supply flow path 3 can be communicated with the compressed air pipeline 1 at the work site, the compressed air pipeline 1 delivers compressed air to the pneumatic vibrator 8 through the air supply flow path 3, the sealing pressure tube of the dome valve 19 disposed at the bottom end of the blanking tube 20 and communicated with the blanking tube 20 is communicated with the first normally open pneumatic valve 4 disposed on the air supply flow path 3 for controlling the on-off of the air supply flow path 3 through the first control air path 9, the first normally open pneumatic valve 4 is linked with the dome valve 19, and along with the on-off of the dome valve 19 at the bottom end of the feeding tube, the first normally open pneumatic valve 4 automatically raps and stops, so as to realize the linkage of the pneumatic vibrator 8 and the dome valve 19 at the bottom end of the blanking port of the original equipment.

In addition, the pneumatic vibrator 8 is easily an air hammer type vibrator or a pulse type vibrator, and the connection between the pneumatic vibrator 8 and the outer wall of the blanking pipe 20 is easily a magnetic type or a bracket welding type, and can also be a hoop type or a thread type.

In some embodiments, a first vent flow path 14 is provided on the bin pump 16 for communicating with the external environment, the coordinated control assembly further comprises a second normally open pneumatic valve 12 provided on the first vent flow path 14 and a second control air path 11 communicating the second normally open pneumatic valve 12 and the sealed pressure tube of the dome valve 19, the coordinated control assembly further configured to: when the dome valve 19 is closed, the sealed air supply flow flowing through the sealed pressure tube flows through the second control air path 11 to the second normally open pneumatic valve 12, so that the second normally open pneumatic valve 12 is closed; when the dome valve 19 opens, the gas in the second control circuit 11 is vented through the sealed pressure tube to open the second normally open pneumatic valve 12.

In the above embodiment, the dome valve 19 at the bottom end of the blanking pipe 20 can be a feeding dome valve of the bin pump 16, the feeding dome valve is used for controlling the on-off of the blanking pipe 20, the second normally-open pneumatic valve 12 is controlled to be linked with the feeding dome valve arranged at the bottom end of the blanking pipe 20, when the feeding dome valve is opened, the second normally-open pneumatic valve 12 is opened, the bin pump 16 is communicated with the external environment, in the unloading process, the gas inside the bin pump 16 can be discharged through the first exhaust flow path 14, so that the effect of pressure relief inside the bin pump 16 in the unloading process is achieved, and smooth unloading is facilitated. When the feed dome valve closes, the second normally open pneumatic valve 12 closes and the silo pump 16 no longer exhausts to the outside environment through the first exhaust flow path 14. Wherein, the first pneumatic valve 4 of normally opening and the second pneumatic valve 12 of normally opening can adopt the pneumatic stop valve of normally opening, the pneumatic ball valve of normally opening, the pneumatic gate valve of normally opening etc. and the first pneumatic valve 4 of normally opening and the second pneumatic valve 12 of normally opening can be the pneumatic valve of normally opening for the nonoculture. The first normally open air-operated valve 4 and the second normally open air-operated valve 12 are closed when air is supplied and are kept normally open when air is not supplied, which is well known in the art and will not be described herein.

In some embodiments, the linkage control assembly includes a master control gas circuit 6, the end of the first control gas circuit 9 away from the first normally-open pneumatic valve 4 and the end of the second controller away from the second normally-open pneumatic valve 12 are both communicated with the sealed pressure pipe of the dome valve 19 through the master control gas circuit 6, and the master control gas circuit 6 is provided with a first valve 7.

In the above embodiment, when the dome valve 19 at the bottom end of the blanking pipe 20 is required to be linked with the first normally-open pneumatic valve 4 and the second normally-open pneumatic valve 12, the first valve 7 is opened, the sealed pressure pipe of the dome valve 19 at the bottom end of the blanking pipe 20 is communicated with the first normally-open pneumatic valve 4 through the master control gas circuit 6 and the first control gas circuit 9, the sealed pressure pipe of the dome valve 19 at the bottom end of the blanking pipe 20 is communicated with the second normally-open pneumatic valve 12 through the master control gas circuit 6 and the second control gas circuit 11, when the dome valve 19 at the bottom end of the blanking pipe 20 is not required to be linked with the first normally-open pneumatic valve 4 and the second normally-open pneumatic valve 12, the first valve 7 can be closed, wherein the first valve 7 can be a manual valve, an electromagnetic valve or a pneumatic valve.

In some embodiments, a second valve 5 is arranged on the first control air path 9, and is used for controlling the on-off of the first control air path 9; and a third valve 10 is arranged on the second control gas circuit 11 and is used for controlling the on-off of the second control gas circuit 11, and the dome valve 19 arranged at the bottom end of the blanking pipe 20 can be selectively linked with the first normally-open pneumatic valve 4 and the second normally-open pneumatic valve 12 according to the actual application requirements by opening and closing the second valve 5, the third valve 10 and the first valve 7 arranged on the master control gas circuit 6. The opening and closing of the first valve 7, the second valve 5 and the third valve 10 may be combined in any form, and will not be described herein.

In some embodiments, a fourth valve 13 is disposed on the first exhaust flow path 14 between the bin pump 16 and the second normally open pneumatic valve 12. The fourth valve 13 is used for controlling the on-off of the first exhaust flow path 14 to control the communication and the cut-off of the bin pump 16 with the external environment.

In some embodiments, a fifth valve 2 is disposed on the air supply flow path 3 to switch the air supply of the air supply flow path according to the actual application requirement.

In the above embodiment, one end of the air supply flow path 3 is communicated with the pneumatic vibrator 8, the other end of the air supply flow path 3 can be communicated with the compressed air pipeline 1 at a working site, the fifth valve 2 can be arranged between the first normally-open pneumatic valve 4 and the compressed air pipeline 1 or between the pneumatic vibrators 8, the fifth valve 2 is in an open state, the first normally-open pneumatic valve 4 can control the on-off of the air supply flow path 3 through the on-off control of the first normally-open pneumatic valve 4, so as to control the vibration and stop of the pneumatic vibrator 8, and when the fifth valve 2 is in a closed state, the first normally-open pneumatic valve 4 can vibrate the uncontrollable pneumatic vibrator 8 after being opened.

In some embodiments, the rapping device further comprises a second exhaust gas flow path 17 communicating the bin pump 16 and the lower hopper 22, the second exhaust gas flow path 17 being provided with a sixth valve 18.

In the above embodiment, the bin pump 16 is communicated with the blanking hopper 22 through the second exhaust flow path 17, the second exhaust flow path 17 is also used for exhausting the gas in the bin pump 16 for smooth discharge, the sixth valve 18 provided on the second exhaust flow path 17 may be an exhaust dome valve, and the exhaust dome valve may be configured to be closed synchronously when the dome valve 19 is closed; the exhaust dome valve is opened simultaneously as the dome valve 19 is opened.

In some embodiments, a shut-off valve 21 is provided between the feed pipe 20 and the feed hopper 22. The shut-off valve 21 can be configured as a manual gate valve, which is normally always in an open state.

In some embodiments, the number of the pneumatic vibrators 8 is plural, and each pneumatic vibrator 8 is communicated with the air supply flow path 3. The plurality of pneumatic vibrators 8 can be arranged on the outer wall of the blanking pipe 20 at intervals along the circumferential direction of the blanking pipe 20, and the plurality of pneumatic vibrators 8 can simultaneously perform rapping on the outer wall of the blanking pipe 20, so that the rapping effect is better. In addition, a plurality of pneumatic vibrators 8 may be arranged side by side on the outer wall of the blanking pipe 20 along the axial direction, and the position and arrangement manner of the pneumatic vibrators 8 on the outer wall of the blanking pipe 20 are not limited herein.

The rapping device provided by the present disclosure can be applied to any suitable application scenario according to practical application requirements, for example, can be applied to the scenario of material unloading, and also can be applied to the scenario of ash discharge, for example, the hopper 22 of the rapping device provided by the present disclosure can be the ash hopper of an electric dust collector, and thus, the rapping device can be combined with the electric dust collector to prevent the problems of ash discharge, such as unsmooth ash discharge.

Another aspect of the present disclosure provides an electric dust-collecting and ash-conveying system, which includes an electric dust collector and the rapping apparatus in the above embodiments, wherein the ash bucket of the electric dust collector is a discharging hopper 22.

The working process of the rapping device in the electric dust removal ash conveying system is exemplarily disclosed, wherein a dome valve 19 arranged at the bottom end of a blanking pipe 20 is a feeding dome valve, when an ash hopper conveys ash into a bin pump 16 through the blanking pipe 20, the ash content of coal is large, and the ash flowability is poor, so that the ash is not smooth, a third valve 10 on a second control gas circuit 11 and a fourth valve 13 on a first exhaust flow path 14 can be closed, the feeding dome valve is only linked with a first normally open pneumatic valve 4, when the feeding dome valve arranged at the bottom end of the blanking pipe 20 is opened, a sealed pressure pipe of the feeding dome valve discharges gas in the first normally open pneumatic valve 4, so that the first normally open pneumatic valve 4 is in an opening state, a gas supply flow path 3 provides gas for a pneumatic vibrator 8, the pneumatic vibrator 8 starts to vibrate the wall of the blanking pipe 20, the flowability of the ash is enhanced, and the ash conveying speed is accelerated; when the feeding dome valve is closed, the sealed pressure pipe of the feeding dome valve inputs control gas to the first normally-open pneumatic valve 4, so that the first normally-open pneumatic valve 4 is in a closed state, the gas supply flow path 3 does not provide gas for the starting vibrator any more, and the pneumatic vibrator 8 stops vibrating. When ash discharge is not smooth due to unsmooth exhaust, the second valve 5 on the first control gas circuit 9 and the fifth valve 2 on the air supply flow path 3 can be closed or only the fifth valve 2 on the air supply flow path 3 is closed, at the moment, the feeding dome valve is linked with the second normally-open pneumatic valve 12, when the feeding dome valve is opened, the sealed pressure pipe of the feeding dome valve discharges the gas in the second normally-open pneumatic valve 12, so that the second normally-open pneumatic valve 12 is in an opening state, the bin pump 16 can be communicated with the external environment through the first exhaust flow path 14 to discharge the gas to the external environment, and therefore the ash discharge is not smooth due to the pressure inside the bin pump 16 can be prevented; when the feed dome valve is closed, the feed dome valve's sealed pressure tube feeds gas into the second normally open pneumatic valve 12 so that the second normally open pneumatic valve 12 is in a closed state and the silo pump 16 is no longer in communication with the outside environment. When the ash content of coal is large, the ash flowability is poor and the air exhaust is not smooth, the feeding dome valve can be linked with the first normally-open air-operated valve 4 and the second normally-open air-operated valve 12, and the pneumatic vibrator 8 vibrates the outer wall of the blanking pipe 20, and meanwhile the bin pump 16 discharges the gas in the bin pump 16 out of the bin pump 16 through the first air exhaust flow path 14, so that the ash discharge is smooth. When the ash discharge is complete, the ash can be transported out of the bin pump 16 via a transport conduit 15 in communication with the bin pump 16.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. A rapping device, characterized in that it comprises:

the blanking pipe is communicated between a discharge opening of the blanking hopper and a feed inlet of the bin pump;

the pneumatic vibrator is arranged on the outer wall of the blanking pipe;

the air supply flow path is communicated with the pneumatic vibrator and is used for providing an air source for the pneumatic vibrator; and

the linkage control assembly comprises a first normally-open pneumatic valve arranged on the air supply flow path, a dome valve arranged at the bottom end of the blanking pipe and a first control air path for communicating the first normally-open pneumatic valve with a sealed pressure pipe of the dome valve, and is configured to: when the dome valve is closed, the sealed air source flowing through the sealed pressure pipe flows to the first normally open pneumatic valve through the first control air passage, so that the first normally open pneumatic valve is closed; when the dome valve is open, gas within the first control gas path is vented through the sealed pressure tube to open the first normally open pneumatic valve.

2. A rapping device as claimed in claim 1, wherein a first exhaust flow path is provided on said bin pump for communication with an external environment, said linkage control assembly further comprising a second normally open pneumatic valve provided on said first exhaust flow path and a second control gas path communicating said second normally open pneumatic valve with a sealed pressure tube of said dome valve, said linkage control assembly further being configured to: a seal gas source flow through said seal pressure tube through said second control gas path to said second normally open pneumatic valve to close said second normally open pneumatic valve when said dome valve is closed; when the dome valve is opened, gas in the second control gas path is exhausted through the sealed pressure tube to open the second normally open pneumatic valve.

3. The rapping device of claim 2, wherein the linkage control assembly includes a master control gas circuit, one end of the first control gas circuit away from the first normally-open pneumatic valve and one end of the second controller away from the second normally-open pneumatic valve are both communicated with the sealed pressure pipe of the dome valve through the master control gas circuit, and the master control gas circuit is provided with a first valve.

4. A rapping device according to claim 3, wherein a second valve is arranged on said first control gas path, and a third valve is arranged on said second control gas path.

5. A rapping device according to claim 2, wherein said first exhaust gas path is provided with a fourth valve located between said bin pump and said second normally open pneumatic valve.

6. A rapping device in accordance with claim 1, wherein a fifth valve is arranged on said gas supply line.

7. A rapping device according to claim 1, wherein said rapping device further comprises a second exhaust flow path communicating said bin pump and said hopper, said second exhaust flow path being provided with a sixth valve.

8. A rapping device according to claim 1, wherein a shut-off valve is provided between said blanking pipe and said blanking hopper.

9. A rapping device in accordance with claim 1, wherein the number of said pneumatic vibrators is plural, each of said pneumatic vibrators being in communication with said air supply flow path.

10. An electric dust and ash removing system, which is characterized in that the electric dust and ash removing system comprises an electric dust remover and a rapping device according to any one of claims 1-9, wherein an ash hopper of the electric dust remover is the discharging hopper.