JP2008296137A - Automatic cleaning device of element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic cleaning device of an element guaranteeing sealability over a long period. <P>SOLUTION: Fluid cylinders 12 are disposed outside the end face of an element container 10 of sealed structure, piston rods 12A are extended into the container penetrating through an end face 11 of the container, working fluid is supplied to first and second fluid chambers and discharged by a fluid supply device control device 14, the piston rods 12A of the fluid cylinders are advanced and retarded, a brush 13 is reciprocated along the center axial direction of the element outer face by the movement of the piston rods, to slidingly contact the element outer face and to clean the element. The pressure of the second fluid chamber of the fluid cylinder is controlled to be higher than the pressure in the container by pressure control devices 15, 16, 17, 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic element cleaning apparatus, and more particularly to an automatic element cleaning apparatus that can guarantee sealing performance over a long period of time.

  For example, in the semiconductor manufacturing process, if dust is scattered in the air, it may cause a product defect. Therefore, a filter is incorporated in the process and the dust is removed by the filter.

  By the way, in the semiconductor manufacturing process, explosive gas such as silane gas, or toxic gas or flammable gas is often used. It is necessary to replace air with nitrogen or the like, which takes a lot of time and a method for automatically cleaning the filter is strongly demanded.

  Conventional filter automatic cleaning methods include a method in which a brush is provided in a filter device and cleaned by sliding the brush against the inner peripheral surface of the filter element while rotating the brush (Patent Document 1). A method of cleaning by spraying a liquid or a gas (Patent Document 2) is known.

Japanese Patent Laid-Open No. 01-128644 JP 2005-13779 A

  By the way, when using a brush or a cleaning nozzle as described above, it is necessary to install those drive motors outside the filter device in relation to the space in the filter device. It is necessary to penetrate the shaft into the filter device.

  However, the inside of the filter device is generally an atmosphere of toxic gas or flammable gas and must be shielded from the outside air, and it is necessary to provide a seal at the penetrating part of the rotating shaft. If so, there is a concern that the gas in the filter device may be worn out and leak to the outside.

  An object of the present invention is to provide an automatic cleaning device for an element that can ensure sealing performance over a long period of time.

  Therefore, an element automatic cleaning device according to the present invention is a cleaning device that automatically cleans a cylindrical element, and is disposed outside an end face of a sealed container containing the element, and is described above by a piston. A first fluid chamber far from the container and a second fluid chamber close to the container are divided, and the piston rod is expanded and contracted by supplying and discharging the working fluid to and from the two fluid chambers. A fluid cylinder that extends through the container, a fluid supply control device that supplies and discharges the working fluid to and from the first fluid chamber and the second fluid chamber of the fluid cylinder, and has a ring shape. It is attached to the tip of the piston rod, and is slidably contacted with the outer surface of the element while reciprocating along the central axial direction of the outer surface of the element by expansion and contraction of the piston rod. And a pressure control device for controlling the fluid supply control device so that the pressure of the second fluid chamber of the piston is higher than the pressure in the container. To do.

  One of the features of the present invention is that the pressure in the second fluid chamber of the fluid cylinder is controlled to be higher than the pressure in the container. Thereby, the gas in a container does not leak from the penetration part of a piston rod, but a sealing performance can be ensured over a long period of time.

  The pressure in the second fluid chamber of the fluid cylinder only needs to be controlled to be higher than the pressure in the container. For example, a pressure detection means for detecting the pressure in the second fluid chamber of the fluid cylinder is provided, and the pressure control device It can be configured to receive the signal of the pressure detection means and control the working fluid to be supplied to the second fluid chamber when the pressure of the second fluid chamber drops below the pressure in the container.

  Further, the brush may be in the form of a ring and slidably contacted with the outer surface of the element. For example, the inner surface of the container can be further cleaned using the reciprocating motion of the brush. That is, the container and the element are arranged concentrically, and the brush can be formed in a ring shape that is in sliding contact with the outer surface of the element and the inner surface of the container.

  Further, in order to improve the cleanliness of the element, it is possible to further include a back cleaning device for flowing a cleaning fluid from the inside of the element to the outside.

  The present invention can be widely applied to cleaning of cylindrical members (elements), and can be applied to cleaning of filter elements of filter devices in a semiconductor manufacturing process, for example. That is, when the element is a filter element of a filter device and the container is a filter container containing a filter element, an automatic cleaning device for the element can be incorporated in the filter device, and its practical effect is great.

  Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 3 show a preferred embodiment of a filter element automatic cleaning apparatus according to the present invention. In the figure, the filter device is configured by concentrically arranging cylindrical filter elements (elements) 30 in a container 10 and sealed with a lid (container end surface) 11, and a gas inlet 10 </ b> A is formed in the container 11. A gas outlet 10B is formed in the lid 11, and a gas G1 to be cleaned is introduced into the container 10 from the inlet 10A, passes through the filter element 30, and dust is filtered. It is discharged outward from the outlet 10B.

  A plurality of air cylinders (fluid cylinders) 12 are fixed to the lid 11 of the container 10 of the filter device on the same circumference while being spaced apart from each other and sealed by an O-ring 12E. The piston 12B is divided into a first air chamber 12C far from the container 10 and a second air chamber 12D close to the container 10.

  A piston rod 12A is fixed to the piston 12B, the piston rod 12A extends through the through hole of the lid 11 of the container 10 into the container 10, and a ring-shaped brush 13 is fixed to the tip of the piston rod 12A. The brush 13 is reciprocated in the direction of the central axis of the filter element 30 by the expansion and contraction of the piston rod 12A so as to slidably contact the outer peripheral surface of the filter element 30 and clean the filter element 30.

  Air passages 14A and 14B are connected to the first and second air chambers 12C and 12D of the air cylinder 12, and a speed controller 19 for controlling air pressure and supply / discharge switching control are provided in the middle of the air passages 14A and 14B. A switching valve 14 is provided, and an air introduction passage 14A of the switching valve 14 is connected to an air source (not shown) of 0.7 MPa, for example.

  A fluid supply control device that supplies and discharges air to the first fluid chamber 12C and the second fluid chamber 12D of the air cylinder 12 by the air passages 14A and 14B, the speed controller 19, the switching valve 14, and the air discharge passage 14D. It is configured.

  An air discharge passage 14D of the switching valve 14 is connected to an air tank 15, and an electromagnetic valve 16 and a primary pressure adjusting valve 17 are connected to the air tank 15, and an outlet of the primary pressure adjusting valve 17 is open to the atmosphere. .

  Further, a pressure switch (pressure detecting means) 18 for detecting that the pressure of the second air chamber 12D has become a set value or less is connected to the air passage 14B, and a signal of the pressure switch 18 is input to the control circuit 20. The control circuit 20 controls the opening and closing of the electromagnetic valve 16.

  When the air tank 15, the electromagnetic valve 16, the primary pressure regulating valve 17 and the control circuit 20 receive the signal from the pressure switch 18 and the pressure in the second air chamber 12 </ b> D falls below the pressure in the container 10, A pressure control device is configured to control the fluid supply control device so that the pressure of the second fluid chamber 12D of the air cylinder 12 is higher than the pressure in the container 10 by supplying air to the second air chamber 12D. Yes.

  FIG. 3 shows an example of the configuration of the air supply system of this example. In the figure, 40 is a differential pressure detector, 41, a bypass passage, and 42, 43 are electromagnetic valves.

  In the element automatic cleaning device of this example, even when the air in the second air chamber 12D of the air cylinder 12 is removed, the pressure in the second air chamber 12D does not become lower than the pressure in the container 10. The reciprocating motion of the piston rod 12A is performed by the switching valve 14.

  When the air G1 to be cleaned is taken in from the intake port 44, it is sent into the container 10 from the inlet 10A through the electromagnetic valve 42, filtered by the filter 30, and the cleaned air G2 is discharged from the outlet 10B.

  The pressure difference between the inlet 10A and the outlet 10B is detected by the differential pressure detector 40. When the differential pressure exceeds a set value, the filter 30 is clogged, so switching is performed by a signal from the differential pressure detector 40. The valve 14 is actuated to supply air to the first air chamber 12C of the air cylinder 12, and the air in the second air chamber 12D is released. At the same time, the electromagnetic valves 42 and 43 are closed, thereby the filter 30. Cleaning starts.

  Now, when the switching valve 14 is switched to the U side, the first air chamber 12C has a high pressure of 0.7 MPaG (gauge pressure), the second air chamber 12D is connected to the air tank 15, and the air tank 15 Is connected to the outside air via a solenoid valve 16 and a primary pressure regulating valve 17.

  During cleaning, the electromagnetic valve 16 is opened, while the primary pressure regulating valve 17 serves to prevent the inlet pressure from becoming 0.1 MPaG or less. When the inlet pressure of the primary pressure regulating valve 17 is 0.1 MPaG or more, the air is discharged to the outside air, and when the inlet pressure becomes less than 0.1 MPaG, the release of air is stopped. Therefore, the inlet pressure of the primary pressure regulating valve 17 does not become less than 0.1 MPaG, and the second air chamber 12D is also connected when the second air chamber 12D is connected to the air tank 15 via the switching valve 14. Is also maintained at 0.1 MPaG or more.

  When the switching valve 14 is switched to the D side, the second air chamber 12D has a high pressure of 0.7 MPaG (gauge pressure), and the first air chamber 12C is connected to the air tank 15 and connected to the first air chamber. The air in 12C is discharged to the air tank 15, and the piston rod 12A is expanded and contracted relative to the air cylinder 12 by the differential pressure between the first and second air chambers 12C and 12D. The filter element 30 is reciprocated along the central axis while being in sliding contact with the outer peripheral surface. The filter element 30 is cleaned by repeating this operation.

  The switching valve 14 employs a known structure that switches between supply and release of air by switching the valve body against the spring force when the first and second air pressures 10C and 10D reach the set pressure. ing.

  Note that if the electromagnetic valve 16 is first opened and 0.7 MPa of air is supplied to the air tank 15, the tank pressure becomes 0.1 MPaG by the primary pressure adjusting valve.

  During cleaning, the pressure in the second air chamber 12D does not become 0.05 MPaG or less in the container 10, and the gas in the container 10 does not leak to the outside.

  However, when the primary pressure regulating valve 17 is malfunctioning, the pressure in the second air chamber 12D may be 0.05 MPaG or less in the container 10. Therefore, a pressure switch (pressure detecting means) 18 is provided in the second air chamber 12D, and the detected pressure is set to 0.08 MPaG, for example. When the pressure switch 18 detects, an alarm is generated, and if the switching valve 14 is forcibly switched to the D side, the second air chamber 12D becomes high pressure, and there is no risk that the gas in the container 10 leaks to the outside. It will be resolved.

  Here, since the space between the air cylinder 12 and the lid 11 of the container 10 is sealed by the O-ring 12E, the gas in the container 10 is less likely to leak from between the air cylinder 12 and the lid 11. If there is a possibility of leakage, it is a gas leak to the second air chamber 12D through the outer peripheral clearance of the piston rod 12A.

  Since the second air chamber 12D drives the piston 12B, air enters and exits, and the gas in the container 10 may be mixed into the discharged air. The operating pressure of the air cylinder 12 is 0.7 MPaG when air is introduced, and 0 MPaG when air is removed. Since the gas pressure in the container 10 is about 0.05 MPaG, when the air in the second air chamber 12D is extracted, the air may contain gas in the system.

  Therefore, when the air in the second air chamber 12D is evacuated, if the pressure in the second air chamber 12D does not fall below the pressure in the container 10, for example, 0.1 MPaG, the gas in the container 10 There is no leakage into the air chamber 12D.

  4 and 5 show a second embodiment, in which the same reference numerals as those in FIGS. 1 to 3 denote the same or corresponding parts. In this example, the brush 13 ′ has a ring shape that is in sliding contact with the outer peripheral surface of the filter element 30 and the inner peripheral surface of the container 10, and two brushes 13 ′ are attached to the piston rod 12 </ b> A at intervals, while the bottom portion of the container 10 ′. A dust discharge port 10D is formed so as to be openable and closable as a concave shape inclined toward the center, and a resin coating layer 10C, for example, a Teflon (registered trademark) coating layer is formed on the bottom surface of the container 10 '.

  A dust suction passage 46 is connected to the bottom of the container 10 ′. The suction passage 46 is connected to a filter device 47 through an electromagnetic valve 45, and the filter device 47 is connected to a suction device (not shown) such as a factory. Yes.

  If the amount of fine powder adhering to the filter element 30 is large, fine powder will also adhere to the inner surface of the container 10 ′, and if it accumulates to some extent, the dust will scatter and adhere to the filter element 30, which may shorten the interval between cleaning operations. is there. Therefore, if the container 10 ′ is formed in a cylindrical shape and the brush 13 ′ is manufactured in a ring shape that is in sliding contact with not only the filter element 30 but also the container 10 ′, the fine powder adhering to the container 10 ′ and the filter element 30 can be dropped simultaneously. it can.

  Further, by making the brush 13 'double, the stroke of the air cylinder 12 can be shortened, and by disposing the lid 13A' on the upper brush 13 ', dust can be prevented from being scattered and the filter element 30 can be attached with dust. Can be reduced.

  Furthermore, by coating the bottom of the container 10 'with a resin, dust does not flow backward, and can be discharged smoothly from the discharge port 10D.

  When the cleaning of the filter element 30 is started, the electromagnetic valve 45 is opened, air in the container 10 ′ is sucked, dust is sucked out from the bottom of the container 10 ′, and at the same time, the pressure in the container 10 ′ suddenly increases. In order not to decrease, a small amount of air is supplied from the air supply port 47, whereby the dust dropped from the filter element 30 and the inner surface of the container 10 ′ is sucked out from the container 10 ′ and is applied to the inner surface of the filter element 30 and the container 10 ′. Reattachment is reduced and suppressed.

  FIG. 6 shows a third embodiment, in which the same reference numerals as those in FIGS. 1 to 5 denote the same or corresponding parts. In this example, nitrogen gas is used as the working fluid of the fluid cylinder 12, and a reverse cleaning nozzle (not shown) is provided at the outlet 10 </ b> B of the container 10. A cleaning gas (or a reverse cleaning liquid) is supplied so that the filter element 30 can be back cleaned.

  The fine powder that has entered the filter element 30 can be pushed outward from the filter element 30 by backwashing, thereby extending the interval of the cleaning operation.

It is a block diagram which shows the filter apparatus provided with preferable embodiment of the automatic cleaning apparatus of the element which concerns on this invention. It is a principal part enlarged view which shows the said embodiment. It is a figure which shows the structural example of the air supply system in the said embodiment. It is a figure which shows 2nd Embodiment. It is a figure which shows the structural example of the air supply system in the said embodiment. It is a figure which shows 3rd Embodiment.

Explanation of symbols

10, 10 'container (filter container)
11 Lid 12 Air cylinder (fluid cylinder)
12A Piston rod 12B Piston 12C First air chamber 12D Second air chamber 13, 13 'Brush 14 Switching valve (fluid supply control device)
14A, 14B Air passage (fluid supply control device)
14C Air introduction passage (fluid supply control device)
14D Air discharge passage (fluid supply control device)
15 Air tank (pressure control device)
16 Solenoid valve (pressure control device)
17 Primary pressure regulating valve (pressure control device)
18 Pressure switch (pressure detection means)
20 Control circuit (pressure control device)
30 filter elements

Claims (5)

A cleaning device that automatically cleans a cylindrical element,
Provided outside the end face of the sealed container containing the element, and partitioned by a piston into a first fluid chamber far from the container and a second fluid chamber close to the container, working fluid to the two fluid chambers The piston rod is expanded and contracted by supply / discharge of the fluid cylinder, and the piston rod extends through the end surface of the container into the container, and
A fluid supply control device for supplying and discharging a working fluid to and from the first fluid chamber and the second fluid chamber of the fluid cylinder;
It forms a ring shape, is attached to the tip of the piston rod, and cleans the element by sliding against the element outer surface while reciprocating along the central axis direction of the element outer surface by expansion and contraction of the piston rod. Brush and
A pressure control device for controlling the fluid supply control device so that the pressure of the second fluid chamber of the fluid cylinder is higher than the pressure in the container;
An automatic cleaning device for an element, comprising:   The pressure control device receives a signal from a pressure detecting means for detecting the pressure in the second fluid chamber of the fluid cylinder, and the second fluid chamber has a second pressure when the pressure in the second fluid chamber drops below the pressure in the container. 2. The element automatic cleaning device according to claim 1, wherein the fluid chamber is controlled to be supplied with a working fluid.   2. The element automatic cleaning device according to claim 1, wherein the container and the element are arranged concentrically, and the brush has a ring shape in sliding contact with the outer surface of the element and the inner surface of the container.   2. The element automatic cleaning device according to claim 1, further comprising a back cleaning device for flowing a cleaning fluid from the inside of the element to the outside.   The automatic cleaning device for an element according to claim 1, wherein the element is a filter element of a filter device, and the container is a filter container containing the filter element.

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