JP2010012419A - Cleaning method of filter in dust collector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method of a filter in a dust collector which is capable of improving the back-washing effect by reliably carrying out expansion and contraction of the filter. <P>SOLUTION: During back-washing of a filter by jetting a cleaning gas in the reverse direction to that in a dust collecting step, an operation of flowing gas in the same direction as that in the dust collecting step is intermittently carried out to forcibly contract the filter expanded by the jetting of the cleaning gas by the gas flowing in the same direction as that in the dust collecting step, and thus the efficiency of the back-washing by repeating expansion and contraction is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a filter cleaning method in a dust collector, and more particularly, to a filter cleaning method in a dust collector having a reverse cleaning step in which a filter is reversely cleaned by flowing a cleaning gas in a direction opposite to that in the dust collection step.

In a dust collector that removes dust in the gas using a filter, the cleaning gas is ejected into the filter in the direction opposite to that during the dust collection process, thereby performing a reverse cleaning process in which dust attached to the filter surface is removed. The dust capacity is recovered, and the dust collection process can be performed continuously for a long time (see, for example, Patent Document 1).
JP 2007-175635 A

  However, if the dust adhering to the surface of the filter is adhering, the dust can be removed sufficiently by simply passing the cleaning gas through the filter in the reverse direction of the dust collection process in the reverse cleaning process. However, the continuous operation time is shortened as compared with the case of dust that gradually accumulates thick and does not have adhesiveness.

  Therefore, the cleaning gas is intermittently ejected into the filter, and the filter expanded by the cleaning gas is contracted by the restoring force of the filter itself when the cleaning gas is not introduced, and this expansion and contraction are repeated. By doing so, the reverse cleaning effect is improved. However, if a large amount of adhesive dust adheres to the surface, the filter may not sufficiently shrink only with the restoring force of the filter itself, and the effect of backwashing by repeated expansion and contraction may not be achieved sufficiently. there were.

  Therefore, an object of the present invention is to provide a filter cleaning method in a dust collector that can improve the effect of back cleaning by reliably performing expansion and contraction of the filter.

  In order to achieve the above object, the filter cleaning method in the dust collector of the present invention is the reverse of the filter cleaning method in the dust collector in which the cleaning gas is jetted in the reverse direction to that in the dust collection step to perform reverse cleaning of the filter. During the cleaning, the gas flow operation is intermittently performed in the same direction as in the dust collection process.

  The filter cleaning method in the dust collector of the present invention includes a partition wall that divides the inside of the housing into an inflow chamber and an outflow chamber, a bottomed cylindrical bag filter that protrudes from the partition wall toward the inflow chamber, A cleaning gas jetting part for jetting cleaning gas into the bag filter from the outflow chamber side, a dust-containing gas introduction path for introducing dust-containing gas into the inflow chamber, and a dust-containing gas provided in the dust-containing gas introduction path A dust gas introduction valve, a dust-free gas lead-out path for drawing dust-free gas from the outflow chamber, a dust-free gas lead-out valve provided in the dust-free gas lead-out path, and the dust-free gas in the dust-free gas lead-out path A method for cleaning a filter in a dust collector comprising a gas suction device provided on the downstream side of a gas outlet valve, an open path for opening the outflow chamber to outside air, and an open valve provided in the open path, The dust-containing gas inlet valve and the dust-free gas outlet valve The dust-free gas outlet valve is closed while the cleaning gas is jetted into the bag filter by reversely cleaning the bag filter while the opening valve is closed. The opening valve is closed and the operation of sucking the gas in the outflow chamber with the gas suction device is intermittently performed.

  According to the filter cleaning method in the dust collector of the present invention, the filter expanded by the gas flowing in the direction opposite to that during the dust collection process can be forcibly contracted. Cleaning can be performed efficiently.

  FIG. 1 to FIG. 3 are explanatory views showing an embodiment of a dust collector to which the filter cleaning method in the dust collector of the present invention is applied, and FIG. 1 is an explanation showing the state of the dust collector when the dust collecting step is performed. FIG. 2 is an explanatory view showing the state of the dust collector when performing a reverse cleaning operation, and FIG. 3 is an explanatory view showing the state of the dust collector when performing a shrinking operation. 4 and 5 are for explaining the expansion and contraction of the bag filter. FIG. 4 is an explanatory view showing the state of the bag filter expanded during the back washing operation. FIG. 5 is contracted during the contraction operation. It is explanatory drawing which shows the state of a bug filter. In FIGS. 1 to 3, the white valve represents an open state, and the black valve represents a closed state.

  In the dust collector, the inside of the housing 11 is partitioned into an inflow chamber 13 and an outflow chamber 14 by a partition wall 12, and a plurality of bottomed cylindrical bag filters 15 project from the partition wall 12 toward the inflow chamber 13. The inflow chamber 13 is connected to a dust-containing gas introduction path 17 for introducing dust-containing gas generated in a combustor 16 such as a combustion abatement device. A collection container 18 that collects dust that has fallen off the bag filter 15 by cleaning is detachably provided. The outflow chamber 14 is connected to a dust-free gas extraction path 19 for extracting the dust-free gas removed by the bag filter 15, and cleaning gas is introduced into the bag filter 15 from the opening of the bag filter 15. A cleaning gas ejection portion 20 is provided for ejection.

  The dust-containing gas introduction path 17 and the dust-free gas outlet path 19 are connected by a bypass path 22 having a bypass valve 21, and a dust-containing gas introduction valve 23 is connected to the dust-containing gas introduction path 17 with a dust-free gas. A dust-free gas outlet valve 24 is provided in the outlet path 19. Further, the dust-containing gas introduction path 17 is provided with a pressure gauge 25 for monitoring the state of the bag filter 15, and the dust-free gas extraction path 19 draws out the dust-free gas from the outflow chamber 14. A gas suction device 26 is provided, and an open path 28 having an open valve 27 for opening the outflow chamber 14 to the outside air during backwashing is provided.

  This dust collector performs a continuous dust collection process by repeating the dust collection process shown in FIG. 1 and the back washing process shown in FIGS. 2 and 3. First, in the dust collection step shown in FIG. 1, the dust-containing gas introduction valve 23 and the dust-free gas outlet valve 24 are open, the bypass valve 21 and the open valve 27 are closed, and the gas suction device 26 is operating. 20 is stopped.

  Accordingly, the gas suction device 26 sucks the dust-free gas in the outflow chamber 14 through the dust-free gas lead-out valve 24 and the dust-free gas lead-out path 19, and the inflow chamber has a relatively higher pressure than the outflow chamber 14. When the dust-containing gas in 13 flows through the bag filter 15 to the outflow chamber 14, dust (solid matter) contained in the dust-containing gas is captured by the outer peripheral surface of the bag filter 15 and removed from the gas. When the pressure of the dust-containing gas sucked into the inflow chamber 13 from the dust-containing gas introduction path 17 is measured by the pressure gauge 25 and reaches a preset pressure, that is, the differential pressure before and after the filter reaches a constant value. The dust collection process is switched to the back washing process.

  In the reverse cleaning step, first, a reverse cleaning operation with a cleaning gas is performed, which is the same as a generally performed reverse cleaning step. In this reverse cleaning operation, as shown in FIG. 2, the opening valve 27 is opened, the dust-containing gas introduction valve 23, the dust-free gas outlet valve 24 and the bypass valve 21 are closed, the gas suction device 26 is in operation, The gas ejection part 20 starts operation.

  The cleaning gas ejection unit 20 ejects the cleaning gas introduced from the cleaning gas introduction path 20a continuously while sequentially moving the ejection nozzles 20b with respect to the openings of the plurality of bag filters 15. The cleaning gas is jetted into the bag filter 15 in order. Thereby, in each bag filter 15, the cleaning gas is intermittently introduced. When the cleaning gas is introduced, the bag filter 15 is expanded by the gas pressure, and the ejection nozzle 20 b is moved to the other bag filter 15. When moved, the filter contracts due to the restoring force of the filter itself.

  During the reverse cleaning operation, as shown in FIG. 3, the open valve 27 is closed and the dust-free gas outlet valve 24 is opened, and the gas in the outflow chamber 14 is sucked by the gas suction device 26. By doing so, the contraction operation which contracts the bag filter 15 is performed intermittently. By sucking the gas in the outflow chamber 14 with the suction device 25 in this way, the gas flow in the bag filter 15 flows in the same direction as the dust collection process, and is expanded by the cleaning gas for back cleaning. The bag filter 15 can be forcibly contracted by the gas flow sucked into the suction device 25.

  As shown in FIG. 4, in the bag filter 15 during the reverse cleaning operation, the filter film 15b expands away from the inner support member 15a due to the inflow of the reverse cleaning gas GA injected from the ejection nozzle 20b. The dust D adhering to the surface (outer peripheral surface) of 15b is removed by the flow of the reverse cleaning gas and the energy during expansion, and the adhering material is also peeled off. When the ejection of the cleaning gas GA stops when the ejection nozzle 20b moves to the opening part of the other bag filter 15, the filter film 15b pushes the gas inside the filter into the outflow chamber 14 by the restoring force of the filter itself and opens it. The gas is contracted while being released from the valve 27 through the open path 28 to the outside of the apparatus.

  At this time, since the pressure outside the apparatus is normally atmospheric pressure, the contraction of the filter film 15b ends in a state where the restoring force of the bag filter 15 and the atmospheric pressure are balanced. Therefore, in the case where not only dust that is easily removed but also solid matter having adhesiveness is attached to the surface of the filter film 15b, the shrinkability of the filter film 15b is impaired due to the influence of the attached solid matter. There are times when it becomes in a state where it does not contract sufficiently.

  Thus, even when the filter film 15b is not sufficiently contracted, as shown in FIG. 5, gas is sucked from the outflow chamber 14 by the suction device 25 at a preset time interval as shown in FIG. By flowing the gas GB in the same direction as the dust collection process, the filter film 15b can be contracted until the inner peripheral surface of the filter film 15b comes into close contact with the outer periphery of the support member 15a. As a result, it is possible to secure a sufficient amount of deformation during expansion and contraction, and not only the dust that adheres to the surface of the filter film 15b but also the dust D that has adhesiveness assuredly. The filter film 15b can be peeled off and removed from the surface, and the dust removal function of the bag filter 15 can be reliably recovered.

The exhaust gas discharged from the solar cell manufacturing apparatus is burned by the combustion type exhaust gas processing apparatus and detoxified, and the gas containing dust (solid content) such as SiO ₂ generated at that time is the configuration shown in the embodiment. A trapping experiment was conducted using a dust collector. The composition of the exhaust gas contains trace amounts of SiH ₄ , B ₂ H ₆ , PH ₃ , GeH ₄ , which are harmful components, and a small amount of H ₂ with the balance being N ₂ . The processing conditions in the dust collector are as follows: the filtration rate in the dust collection process is 0.4 m / min, the pressure of the cleaning gas in the reverse cleaning process is 0.6 MPa, the period of the reverse cleaning operation for each bag filter is 12 seconds, and the reverse cleaning process The total time was 60 minutes, and the period of the contraction operation for intermittently contracting the filter with the suction device was 10 minutes.

  Under these conditions, the dust collection process and the back washing process were repeated to perform continuous operation. When the operation of contracting the filter intermittently with the suction device is not performed (conventional example) and when the contraction operation is performed (example of the present invention), immediately before switching from the dust collection process to the back washing process. The pressure difference (ΔP = P1−P2) before and after the reverse cleaning process is calculated from the pressure (P1) measured with the pressure gauge and the pressure (P2) measured with the pressure gauge immediately after switching from the reverse cleaning process to the dust collecting process. Each was calculated. As a result, in the conventional example, the pressure difference (ΔP) was 1.0 kPa, whereas in the example, the pressure difference (ΔP) was 1.7 kPa, and the recovery of the dust collection capacity was larger in the example. I understand that.

It is explanatory drawing which shows the state of a dust collector when performing the dust collection process. It is explanatory drawing which shows the state of a dust collector when performing reverse washing operation. It is explanatory drawing which shows the state of a dust collector when performing shrinkage | contraction operation. It is explanatory drawing which shows the state of the bag filter which expanded during back washing operation. It is explanatory drawing which shows the state of the bag filter shrink | contracted during shrinkage | contraction operation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Housing | casing, 12 ... Partition wall, 13 ... Inflow chamber, 14 ... Outflow chamber, 15 ... Bag filter, 15a ... Supporting member, 15b ... Filter membrane, 16 ... Combustor, 17 ... Dust-containing gas introduction path, 18 ... Recovery container, 19 ... dust-free gas outlet path, 20 ... cleaning gas ejection section, 20a ... cleaning gas introduction path, 20b ... ejection nozzle, 21 ... bypass valve, 22 ... bypass path, 23 ... dust-containing gas introduction valve, 24 ... Dust-free gas outlet valve, 25 ... Pressure gauge, 26 ... Gas suction device, 27 ... Open valve, 28 ... Open path

Claims (2)

  In the filter cleaning method in the dust collector that reversely cleans the filter by jetting cleaning gas in the opposite direction to the dust collection process, the gas is supplied in the same direction as in the dust collection process during the reverse cleaning. A method for cleaning a filter in a dust collector, wherein the flow operation is intermittently performed.   A partition wall that divides the inside of the housing into an inflow chamber and an outflow chamber, a bottomed cylindrical bag filter protruding from the partition wall toward the inflow chamber, and a cleaning gas from the outflow chamber side into the bag filter A cleaning gas jetting part, a dusty gas introduction path for introducing dusty gas into the inflow chamber, a dusty gas introduction valve provided in the dusty gas introduction path, and a dust-free gas from the outflow chamber , A dust-free gas lead-out valve provided in the dust-free gas lead-out path, and a gas suction device provided downstream of the dust-free gas lead-out valve in the dust-free gas lead-out path And a filter cleaning method in a dust collector comprising: an open path for opening the outflow chamber to the outside air; and an open valve provided in the open path, the dust-containing gas introduction valve and the dust-free gas outlet valve The cleaning gas is blown out with the open valve closed. During the reverse cleaning of the bag filter by jetting the cleaning gas from the bag filter, the dust-free gas outlet valve is opened and the open valve is closed to release the gas in the outflow chamber to the gas A method for cleaning a filter in a dust collector, wherein an operation of sucking with a suction device is intermittently performed.

Images