JP2570168B2 - Filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration apparatus, and more particularly to a filtration apparatus for filtering a liquid used in a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art A conventional filtering apparatus will be described with reference to the drawings.

FIG. 7 is a schematic configuration diagram of a conventional filtration device. The liquid supplied from the liquid supply unit 1 is supplied to a liquid input pipe 2
The impurities are removed by passing through the filter section 3 through the filter section 3, and are discharged from the liquid outlet pipe 4. By the way, when performing filtration, air may enter the filter unit 3 for some reason. For example, when air is mixed into the liquid in the liquid supply unit 1 or the filter unit 3 is opened by replacing the filter,
Bubbles are mixed in the liquid inlet pipe 2, the liquid outlet pipe 4, and the filter unit 3. Bubbles in the liquid must be removed because they cause liquid ejection failure and liquid non-uniformity.

Conventionally, air bubbles entering the liquid inlet pipe 2 and the filter section 3 have been removed by a method as shown in FIG. It is assumed that the operator finds bubbles in the pipe (S801) and stops supplying the liquid (S802). Then, the operator closes the liquid outlet valve 6 (S803), opens the air outlet valve 8 (S804), and sends the liquid from the liquid supply unit 1 to the filter unit 3 (S805). Thus, the liquid containing bubbles in the liquid inlet pipe 2 and the filter section 3 is discharged to the drain section 9A through the air outlet pipe 7. At this time, the liquid is supplied until the air bubbles of the liquid in the air outlet pipe 7 disappear. The confirmation of bubbles is performed by visually observing the transparent piping. If the bubbles disappear (S80
The operator opens the liquid outlet valve 4 (S809), closes the air outlet valve 8 (S810),
The liquid is supplied from the liquid supply unit 1. Then, the air bubbles mixed with the liquid outlet pipe 4 are removed by performing an air flow together with the liquid, and after visual confirmation that the air bubbles have disappeared from the pipe (S812), the supply of the liquid is stopped (S813).

[0005]

In the above-mentioned conventional filtering apparatus, when air is mixed into the liquid in the filter section 3, the liquid is forcibly sent out (air flow) to the filter section. For this reason, there has been a problem that a large amount of liquid is required to remove bubbles. Further, as shown in FIG. 9, the filter unit 3 is provided with a filter 26 having a plurality of irregularities formed in a filter housing 25 in order to increase a filtration area. Therefore, when the viscosity of the liquid is high, it is difficult for the liquid to pass through the
It takes a long time to remove air bubbles that have entered inside 6. Further, the presence or absence of air bubbles in the pipe has to be visually confirmed, and the operator has to perform a complicated operation.

An apparatus according to Japanese Patent Application Laid-Open No. 63-260456 has been devised as an apparatus for removing bubbles by vibrating a liquid. This filtration device is provided with an ultrasonic vibrator for applying ultrasonic vibration to liquid ink. However, since this device does not include a means for detecting bubbles (air sensor), a means for automatically opening and closing a valve, and the like, the operation of removing bubbles must be performed automatically. That is, in this filtration device,
The operation of removing the air bubbles cannot be performed automatically, and the operator has been imposed an excessive work load.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a filtration apparatus capable of automatically removing bubbles without flowing a large amount of liquid.

[0008]

According to the first aspect of the present invention,
A filter unit for removing impurities in the liquid, a vibration unit for vibrating the filter unit, an air detection unit for detecting bubbles in the liquid discharged from the filter unit, and a filter until the air detection unit no longer detects bubbles. And a control means for causing the vibration means to vibrate while causing the liquid to flow through the section.

According to a second aspect of the present invention, there is provided a filter section for removing impurities in a liquid, a vibration means for vibrating the filter section, a plurality of pipes connected to the filter section, and a valve provided in each pipe. And air detection means for detecting air bubbles in the liquid passing through the respective pipes, and controlling the opening and closing of the valve, and vibrating the vibration means while flowing the liquid through the filter section until the air detection means no longer detects air bubbles. And a control means for causing the filtration device.

According to a third aspect of the present invention, there is provided a filter for removing impurities in a liquid, a vibrating means for vibrating the filter, first and second pipes respectively connected to the filter, A first valve provided on the first pipe, a second valve provided on the second pipe, first air detection means for detecting bubbles in the liquid passing through the first pipe, and a second valve. A second air detecting means for detecting air bubbles in the liquid passing through the pipe, and a control means for sequentially performing the following processing. Open the first valve and close the second valve. The liquid flows from the filter section to the first pipe. When the first air detecting means stops detecting air bubbles, the first valve is closed and the second valve is opened, and the liquid flows from the filter section to the second pipe. When the second air detecting means stops detecting the air bubbles, the vibration in the vibrating means is stopped.

According to a fourth aspect of the present invention, there is provided the filtration device according to the third aspect, further comprising an air vent for removing air bubbles in the liquid passing through the second pipe.

According to a fifth aspect of the present invention, the air vent portion is provided with a container for storing the liquid, and a pipe for extracting the liquid at the bottom of the container from the liquid stored in the container. Item 5. The filtration device according to Item 4.

[0013]

According to the first aspect of the present invention, the control means causes the liquid to flow through the filter section and causes the filter section to vibrate using the vibration means. This reduces bubbles in the filter section. Then, when the air detecting means stops detecting the air bubbles, the control means stops the vibration in the vibrating means. Therefore, according to the present invention, it is not necessary to use a large amount of liquid for flowing out the bubbles by removing the bubbles by the vibration means. Further, conventionally, it took a relatively long time to discharge the liquid containing bubbles from the filter unit. However, according to the present invention, the bubbles can be removed in a short time by vibrating the filter unit. . Furthermore, since the operation of removing air bubbles can be automatically performed by the control means, the work load on the operator can be reduced.

According to the second aspect of the present invention, the control means controls the opening and closing of the valve and allows the liquid to flow through the filter section. Then, the control unit vibrates the filter unit using the vibration unit, and reduces bubbles in the filter unit. When the air detecting means stops detecting air bubbles in the piping, the control means opens and closes the valve and stops the vibration of the vibrating means. Therefore, according to the present invention, it is not necessary to use a large amount of liquid for flowing out the bubbles by removing the bubbles by the vibration means. In addition, the control means automatically opens and closes a valve, detects bubbles, and the like in association with the air bleeding process, thereby reducing the operator's work load.

According to a third aspect of the present invention, the control means opens the first valve and closes the second valve. Then, the liquid flows from the filter section to the first pipe to remove bubbles in the filter section. When the first air detecting means stops detecting, the control means closes the first valve and opens the second valve to flow the liquid from the filter unit to the second pipe. Thereafter, when the second air detection means no longer detects bubbles, the control means stops the vibration in the vibration means. Thus, according to the present invention,
By removing the bubbles by the vibrating means, it is not necessary to use a large amount of liquid to make the bubbles flow out. Further, by automatically performing the opening and closing work of the valve accompanying the air bleeding processing, the work load on the operator can be reduced.

In the fourth aspect of the present invention, the second pipe according to the third aspect is provided with an air vent for removing air bubbles in the liquid. Therefore, according to the present invention, it is possible to further reduce bubbles in the liquid flowing through the second pipe.

In the fifth aspect of the present invention, a liquid is stored in the container of the air vent. Then, the bubbles in the liquid rise to the upper part of the liquid with time. Therefore, by extracting the liquid at the bottom of the container, it is possible to obtain a liquid that does not contain bubbles.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a filtration device according to a first embodiment of the present invention. In this figure, the liquid supply unit 1
Supplies the liquid to the filter unit 3 via the liquid input pipe 2. The filter unit 3 includes a filter therein and filters the liquid supplied from the liquid supply unit 1. The filtered liquid is discharged from the liquid outlet 11 via the liquid outlet pipe 4. The liquid outlet pipe 4 has a first air sensor 5 for detecting bubbles in the liquid.
Are arranged. The first air sensor 5 is constituted by, for example, a capacitance type sensor or the like. The liquid outlet valve 6 opens and closes the liquid outlet pipe 4, and is composed of an electrically controllable electromagnetic valve or the like. The air outlet pipe 7 is a pipe for discharging the liquid mixed with air bubbles. One end of the air outlet pipe 7 is connected to the filter section 3 and the other end is connected to the drain section 9A. The drainage section 9A contains a liquid containing bubbles. Air outlet piping 7
Air outlet valve 8 and the second air sensor 1
0 has the same configuration as the air outlet valve 6 and the first air sensor 5 described above.

The filter section 3 is provided with a vibrator 9 for applying vibration to the filter section 3. The vibrator 9 includes a piezoelectric vibrator or an electromagnetic vibrator, and removes bubbles in the liquid by applying vibration to the liquid in the filter unit 3. The air release control unit 12 is configured by a microcomputer or the like, and controls the operations of the liquid supply unit 1, the first air sensor 5, the liquid valve 6, the air outlet valve 8, the second air sensor 10, the vibrator 9, and the like. Things.

FIG. 2 is a block diagram of the air release control unit 12. As shown in FIG. A / D converters 121 to 123 are connected to input / output ports of the microcomputer 120. A
The / D converter 121 converts signals output from the air sensors 5 and 10 into digital signals. A / D
The converter 122 converts a digital signal output from the microcomputer 120 into an analog signal. This analog signal is amplified by the amplifier 124,
Input to valves 6 and 8. Thereby, the valves 6 and 8 are configured to open and close according to the input signal. Similarly, the A / D converter 123 and the amplifier 12
Reference numeral 5 is for driving the vibrator 9.

The operation of the filtration device configured as described above will be described with reference to the flowchart of FIG. When the first air sensor 5 detects bubbles in the liquid outlet pipe 4 (S
301), the air release control unit 12 stops the supply of the liquid from the liquid supply unit 1 (S302). Next, the air release control unit 12 closes the opened liquid outlet valve 6 (S30).
3) Open the closed air outlet valve 8 (S30).
4). Then, the air release control unit 12 supplies the liquid from the liquid supply unit 1 to the filter unit 3 (air flow) while vibrating the vibrator 9 attached to the filter unit 3 (S305) (S306). As a result, the bubbles in the liquid are eliminated by the vibration, and the liquid mixed with the bubbles on the liquid inlet side in the filter section 3 is discharged to the liquid discharging section 9A through the air outlet pipe 7.

After the air flow is thus performed for 10 seconds (S307), it is detected by the second air sensor 10 whether or not there are bubbles in the air outlet pipe 7 (S308). Until the second air sensor 10 stops detecting air bubbles (NO in S308), the liquid continues to be flown by air (S30).
7). When the second air sensor 10 stops detecting air bubbles, the closed liquid outlet valve 6 is opened (S309), and the opened air outlet valve 8 is closed (S310).

Next, in order to remove bubbles on the liquid outlet side in the filter section 3, the liquid is flown for 60 seconds (S311).
At this time, the vibrator 9 remains vibrated. The liquid mixed with air bubbles is discharged from the liquid outlet 11 of the liquid outlet pipe 4. Until the first air sensor 5 stops detecting air bubbles, the process of S311 (air flow for 60 seconds) is continued. When the first air sensor 5 no longer detects bubbles (YES in S312), the air release control unit 12 stops the vibration of the vibrator 9 (S313) and stops the liquid supply to the filter unit 3 (S313). S314). Therefore, according to the present embodiment, the bubbles in the liquid can be automatically removed, and the work load on the operator can be reduced.

Next, a description will be given of a filtration apparatus according to a second embodiment of the present invention. FIG. 4 is a schematic configuration diagram of the filtration device according to the present embodiment. In this filtration device, an air vent 13, a third air sensor 14, a second air outlet pipe 15, a second air outlet valve 16, and a second drainage section 17 are arranged in the liquid outlet pipe 4 according to the first embodiment. Things. FIG. 5 is a cross-sectional view of the air vent 13. A first liquid inlet pipe 18 and a second air outlet pipe 15 are connected to an upper portion of the air vent 13. The second liquid outlet pipe 20 is inserted to the deep part of the air vent 13. Normally, bubbles rise to the upper part of the liquid, so that only the liquid at the deep part of the air vent 13 is taken out by the second liquid outlet pipe 20, so that the bubbles in the liquid can be removed. Therefore, according to the present embodiment, it is possible to further reduce the flow rate of the liquid required to discharge bubbles in the pipe from the filter unit 3 to the liquid outlet 11.

Hereinafter, the operation of the filtration device according to the present embodiment will be described with reference to FIG. The first air sensor 19 is the first
When bubbles in the liquid outlet pipe 18 are detected (S601),
The air release control unit 12 stops supplying the liquid from the liquid supply unit 1 to the filter unit 3 (S602). Next, the air release control unit 12 closes the liquid outlet valve 6 provided in the second liquid outlet pipe 20 (S603) and opens the first air outlet valve 22 provided in the first air outlet pipe 21 (S604). ). Then, the air release control unit 12 supplies the liquid to the filter unit 3 while vibrating the vibrator 9 attached to the filter unit 3 (S605) (S60).
6). Thereby, the bubbles in the liquid are reduced, and the liquid in which the bubbles are mixed at the liquid inlet side in the filter unit 3 is discharged to the first drain unit 23 through the first air outlet pipe 21.

After the air flow is thus performed for 10 seconds (S607), the air release controller 12 detects the presence or absence of air bubbles in the first air outlet pipe 21 by the second air sensor 10 (S608). Then, the air flow for 10 seconds is repeated until no bubbles are detected (YES in S608). If no more air bubbles are detected, the second air outlet valve 1
6 (S609) and the first air outlet valve 2
2 is closed (S610). Next, an air flow of the liquid is performed for 10 seconds in order to remove bubbles on the liquid outlet side in the filter unit 3 (S611). At this time, the vibrator 9 remains in a vibrated state.

The air-mixed liquid passes through the air vent 13 to remove bubbles, and the liquid is discharged to the second drain 17 through the second air outlet pipe 15.
Until the first air sensor 19 no longer detects bubbles in the first liquid outlet pipe 18 (NO in S612), the liquid is flown for 10 seconds (S611). Similarly, the third air sensor 1
Until No. 4 no longer detects bubbles in the second air outlet pipe 15 (NO in S614), the liquid is flown for 10 seconds (S613).

Then, the air release control unit 12 controls the vibrator 9
After stopping the vibration (S615), the liquid outlet valve 6 is opened (S617), and the second air outlet valve 16 is closed (S617). Until the fourth air sensor 24 no longer detects bubbles in the second liquid outlet pipe 20 (N in S619)
O) After the liquid is flowed for 10 seconds (S518),
The supply of the liquid is stopped (S620). Thus, the air bleeding of the liquid is completed, and subsequently, the filtration process is performed.

[0030]

As described above, according to the present invention, since bubbles in the liquid are removed by vibrating the filter section, it is not necessary to discharge a large amount of the liquid.
Further, while it has conventionally required a long time to discharge the liquid containing air bubbles from the filter section, according to the present invention, the air bubbles can be removed in a short time by vibrating the filter section. . Further, by automatically opening / closing a valve, detecting air bubbles, and the like in accordance with the air bleeding process by using the control means, it is possible to reduce the work load on the operator.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a filtration device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an air release control unit according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the filtration device according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a filtration device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of an air vent according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the filtration device according to the second embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a conventional filtration device.

FIG. 8 is a flowchart showing the operation of a conventional filtration device.

FIG. 9 is a sectional view of a filter unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid supply part 3 Filter part 4 Liquid outlet pipe (2nd pipe) 5 1st air sensor (2nd air detection means) 6 Liquid outlet valve (2nd valve) 7 Air outlet pipe (1st pipe) Reference Signs List 8 air outlet valve (first valve) 9 vibrator (vibration means) 10 second air sensor (first air detection means) 12 air release control section (control means) 13 air release section 18 first liquid outlet pipe (second 19 first air sensor (second air detecting means) 20 second liquid outlet pipe (second pipe) 21 first air outlet pipe (first pipe) 22 second air outlet valve (first pipe) valve)

Claims (5)

(57) [Claims] 1. A filter for removing impurities in a liquid, a vibrating means for vibrating the filter, an air detecting means for detecting air bubbles in the liquid discharged from the filter, and an air detecting means for detecting air bubbles A control unit for causing the vibration unit to vibrate while flowing the liquid through the filter unit until the filtration is stopped. 2. A filter section for removing impurities in a liquid, a vibration means for vibrating the filter section, a plurality of pipes connected to the filter section, a valve provided on each pipe, and each pipe. Air detection means for detecting air bubbles in the liquid passing therethrough, and control means for controlling the opening and closing of the valve and causing the vibration means to vibrate while flowing the liquid through the filter section until the air detection means no longer detects air bubbles. A filtration device, characterized in that: 3. A filter section for removing impurities in a liquid, a vibrating means for vibrating the filter section, a first pipe connected to the filter section, and a second pipe connected to the filter section.
, A first valve provided in the first pipe, a second valve provided in the second pipe, and a first air detection for detecting bubbles in a liquid passing through the first pipe A filtration device comprising: means, second air detection means for detecting air bubbles in a liquid passing through a second pipe, and control means for sequentially performing the following processing. Open the first valve and close the second valve. The liquid flows from the filter section to the first pipe. When the first air detecting means stops detecting air bubbles, the first valve is closed and the second valve is opened, and the liquid flows from the filter section to the second pipe. When the second air detecting means stops detecting the air bubbles, the vibration in the vibrating means is stopped. 4. The filtering device according to claim 3, further comprising an air vent for removing air bubbles in the liquid passing through the second pipe. 5. The filtering device according to claim 4, wherein the air vent comprises a container for storing the liquid, and a pipe for extracting the liquid at the bottom of the container from the liquid stored in the container. .