JP4088928B2 - Dust removal method and removal apparatus - Google Patents

Description

  The present invention relates to a dust removing method and a removing apparatus for separating and removing harmful dust generated in a semiconductor manufacturing process, a waste treatment process, and the like.

  As a dust removal device used in semiconductor device manufacturing processes, etc., a cylindrical filter is placed in the airflow containing dust, and dust is filtered by letting dust-containing gas flow from the outside to the inside. Therefore, when removing dust from the filter, there is known a dust removing device that rotates the filter and removes dust from the filter by centrifugal force (Patent Document 1).

  Conventionally, the dust removing device of Patent Document 1 is such that this kind of dust removing device flows dust-containing gas from the inside to the outside of the cylindrical filter to filter the dust, and collects the dust collected inside the filter. Since it was removed by the brush (Patent Document 2 and Patent Document 3), it is intended to improve the point that the life of the filter was short due to friction by the brush.

However, the dust removal method of Patent Document 1 cannot sufficiently remove dust only with centrifugal force when the dust is moistened with moisture, oil, viscous dust or the like. And in such a case, there exists a problem that a favorable dust removal process cannot be performed because pressure loss increases.
JP-A-11-57365 Japanese Patent No. 2850169 Japanese Patent No. 2819251

  The present invention has been made in view of the problems of the prior art, and removes dust so as to eliminate clogging without damaging the filter even when the dust collected by the filter is damp. An object of the present invention is to provide a dust removal method and a removal device capable of achieving a longer filter life and maintaining good dust removal capability.

The dust removing method of the present invention is a dust removing method using a dust removing device for filtering and collecting dust from dust-containing gas, the dust removing device comprising a vertically long cylindrical casing, A filter disposed coaxially within the casing and a brush disposed symmetrically about the axis, and the cylindrical casing has a gas inlet on the upper surface and a gas outlet on the lower portion, The outer surface of the filter is coated with a negative charge carrier for preventing fuzz caused by a brush, and the brush is a negative charge carrier, and flows through the dust-containing gas from the outside to the inside of the filter. The dust is collected by filtration, and a brush is brought into sliding contact with the outer peripheral surface of the filter to remove the dust collected by the filter.

  In the dust removing method of the present invention, the brush may be rotated to remove dust, or a certain filter may be rotated to remove dust. In the latter case, the rotation of the filter is preferably controlled by the pressure loss value signal.

The dust removing apparatus of the present invention is a dust removing apparatus for filtering and collecting dust from a dust-containing gas, and the dust removing apparatus has a vertically long cylindrical casing and a coaxial center in the casing. The cylindrical casing has a gas inlet on the upper surface and a gas outlet on the lower portion, and an outer surface of the filter is provided on the outer surface of the filter. The coating is a negative charge carrier for preventing fuzz by the brush, and the brush is a negative charge carrier .

In the dust removing apparatus of the present invention, it is preferable that the brush is provided on an elongated hanger arm formed in a U-shape that is rotationally driven by a motor .

  Since the present invention is configured as described above, even when the dust collected by the filter is moist, the dust is removed so as to eliminate clogging without damaging the filter. An excellent effect is achieved that it is possible to achieve a long life and maintain good dust removal capability.

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

Embodiment 1
FIG. 1 shows a dust removing device (hereinafter simply referred to as a removing device) applied to the dust removing method according to Embodiment 1 of the present invention. This removing device 1 is, for example, a dust in a gas in a semiconductor manufacturing process. A casing 2 comprising an airtight container having a gas inlet 11 for taking in dust-containing gas and a gas outlet 12 for sending out the dust-removed gas; A filter 3 that is stored and filtered to collect dust in the gas introduced into the casing 2 and a brush 4 that performs a regeneration process for scraping dust from the filter 3 so as to regenerate the filtering and collecting function of the filter 3. And a motor 5 for driving the brush 4 as main components.

  The casing 2 and the filter 3 are cylindrical members disposed substantially coaxially. The dust-containing gas taken into the casing 2 from the gas inlet 11 provided on the upper surface of the casing 2 flows through the inside of the casing 2 from the outside to the inside of the filter 3, whereby dust is filtered and collected from the gas. The The filtered gas is sent from the inside of the filter 3 to the outside through a gas outlet 12 provided at the lower part of the casing 2.

The filter 3 is made of felt or felt mixed with polymer fibers, and a coating made of a thin film of PTFE (tetrafluoroethylene), for example, having numerous fine holes on the outer peripheral surface, which is a dust collecting surface. (Fuzz prevention coating ) shall be applied. Although not shown, the filter 3 is supported from the inner surface by a net-like holding member so that its shape does not change.

  The brush 4 is made of, for example, polypropylene (PP), and is provided on a hanger arm 23 that is rotationally driven by the motor 5 via a gear head 21 and a coupling 22. In addition, the material of the brush 4 is not limited to PP, and can be an appropriate material capable of removing dust.

  The hanger arm 23 is an elongated plate-like member formed in a substantially U-shape, and a brush mounting portion 23a (only one brush mounting portion is shown in the figure) corresponding to two U-shaped horizontal lines. And a coupling mounting portion 23b corresponding to one vertical line of a U-shape.

  The two brush mounting portions 23a are arranged so that the inner brush mounting surface 23c is always opposed to the outer peripheral surface of the filter 3 with the filter 3 interposed therebetween, and the brush 4 has its tip at the outer periphery of the filter 3. The brush is attached to the brush attachment surface 23c so as to be in sliding contact with the surface.

The tip portion of the brush mounting part 2 3 a is fastened to the set ring 25 which is loosely fitted in the filter 3, is assumed to its opening is defined.

  Thus, the brush 4 is always driven to rotate by the motor 5 and is in sliding contact with the outer peripheral surface of the filter 3 to perform the regeneration processing of the filter 3. Here, as described above, since the coating made of PTFE is applied to the outer peripheral surface which is the dust collecting surface of the filter 3, even if the filter 4 is rubbed, the surface of the filter 3 is fluffed and damaged. There is nothing. Moreover, since the regeneration process of the filter 3 is performed without interruption by the brush 4, the dust does not adhere to the filter 3 even when the dust collected by filtration is wet, and the filter 3. It is possible to suppress an increase in pressure loss due to clogging and maintain a good filtration function for a long period of time.

  Further, the diameter of the fine pores of the coating can be made sufficiently smaller than the particle size of the dust, and the intrusion of dust into the filter 3 can be minimized. As a result, it is possible to suppress an increase in pressure loss and maintain a good filtering function over a long period of time.

  Further, by forming the brush 4 from polypropylene which is a negative charge carrier similar to PTFE, static electricity is not generated even if they are rubbed with each other, and dust can be easily scraped off from the filter 3. Therefore, an increase in pressure loss due to clogging of the filter 3 can be suppressed, and a good filtration function can be maintained over a long period of time.

Embodiment 2
FIG. 2 shows a dust removing apparatus 1A according to the second embodiment. The second embodiment is a modification of the first embodiment. As shown in the figure, the brush 4A is fixedly provided on the casing 2A, while the filter 3A is rotationally driven by the motor 5A. The outer peripheral surface, which is a collecting surface, is brought into sliding contact with the brush 4A to perform the regeneration process of the filter 3A.

  Here, in the second embodiment, a differential pressure gauge (not shown) that measures the differential pressure inside and outside the filter 3 </ b> A is provided, and a pressure loss value signal based on the measured value is input to the control device 30. The control device 30 refers to the input pressure loss value signal, starts the motor 5A when the pressure loss in the filter 3A reaches a predetermined level or more, and executes the regeneration process of the filter 3A, while the pressure loss is at the predetermined level. When it attenuates below, the motor 5A is stopped, and control is performed so as to stop the execution of the regeneration process.

  With this configuration, it is possible to reduce the running cost by executing the regeneration process only when the pressure loss increases under an operating condition where the regular regeneration process is unnecessary. Further, it is possible to execute the regeneration process of the filter 3A by utilizing the centrifugal force generated by the rotation. Therefore, a further reproduction effect can be expected.

Has been described based on the embodiment of the present invention, the present invention is not limited only to these embodiments but can be variously modified. For example, although the motor drive is used in the second embodiment, it may be a manual drive.

  According to the present invention, even when the dust is damp, it is possible to remove the dust from the filter without damaging the filter and to exhibit a good filtering function.

It is a partial cross section figure which shows the structure of the dust removal apparatus applied to the dust removal method which concerns on Embodiment 1 of this invention. It is a partial cross section figure which shows the structure of the dust removal apparatus applied to the dust removal method which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dust removal apparatus 2 Casing 3 Filter 4 Brush 5 Motor 11 Gas inlet 12 Gas outlet 23 Hanger arm 30 Control apparatus

Claims (6)

A dust removing method using a dust removing device for collecting dust from dust-containing gas by filtration,
The dust removing apparatus includes a vertically long cylindrical casing, a filter disposed coaxially in the casing, and a brush disposed symmetrically about the axis,
The cylindrical casing has a gas inlet on the upper surface and a gas outlet on the lower portion,
The outer surface of the filter is coated with a negative charge carrier for preventing fuzz by a brush,
The brush is a negative charge carrier,
Dust is collected by filtration through the dust-containing gas from the outside to the inside of the filter,
A dust removing method, wherein a brush is slidably brought into contact with the outer peripheral surface of the filter to remove dust collected by the filter. The dust removal method according to claim 1, wherein the dust is removed by rotating a brush. The dust removal method according to claim 1, wherein the dust is removed by rotating the filter. 4. The dust removal method according to claim 3, wherein the rotation of the filter is controlled by the pressure loss value signal. A dust removing device for collecting dust from dust-containing gas by filtration,
The dust removing device comprises a vertically long cylindrical casing, a filter disposed coaxially in the casing, and a brush disposed symmetrically about the axis,
The cylindrical casing has a gas inlet on the upper surface and a gas outlet on the lower portion,
The outer surface of the filter is coated with a negative charge carrier for preventing fuzz by a brush,
The dust removing apparatus , wherein the brush is a negative charge carrier . 6. The dust removing apparatus according to claim 5 , wherein the brush is provided on an elongated hanger arm formed in a U-shape that is rotationally driven by a motor .

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