JP4641266B2 - Deaeration and foreign substance removal device - Google Patents

Description

  The present invention relates to a degassing / foreign substance removing apparatus for degassing a gas from a liquid to be treated and removing foreign substances in the liquid to be treated.

When cleaning an object to be cleaned such as a precision part, an ultrasonic cleaning method is used.
When ultrasonic vibration is applied to the cleaning liquid, a dense wave is formed in the liquid. In the “sparse” state of the sparse / dense wave, the liquid is depressurized to a vapor pressure or less, thereby generating bubbles in which the liquid is vaporized (cavitation). Next, when the part with bubbles becomes “dense”, the bubbles are compressed rapidly while being liquefied by being pushed by the surrounding liquid, and at this time the liquid is at a speed higher than the speed of sound in the liquid. A shock wave is generated by the movement. Due to this shock wave, the surface of the object to be cleaned is cleaned.

When a gas such as oxygen is dissolved in the cleaning liquid, not only the gas in which the liquid is vaporized but also this dissolved gas is mixed in the bubbles generated in the “sparse” state. In this case, even if the bubbles are compressed in the “dense” state, the dissolved gas remains without being liquefied, and the dissolved gas absorbs vibration due to the dense wave. Therefore, it becomes difficult to generate shock waves, and the cleaning efficiency of the object to be cleaned decreases.
Therefore, conventionally, removal of gas in the cleaning liquid (degassing) has been performed in order to increase the cleaning efficiency by ultrasonic cleaning.

  In general, the cleaning liquid is not disposable but is used repeatedly. However, since the foreign matter separated from the surface of the object to be cleaned is mixed in the cleaning liquid that has been used repeatedly, the foreign object may reattach and contaminate the object to be cleaned. Therefore, it is necessary to remove foreign substances from the cleaning liquid before reusing the used cleaning liquid.

Patent Document 1 includes a cleaning tank for storing cleaning liquid, a pump for circulating the cleaning liquid, a degassing tank for degassing the cleaning liquid, and a filter for removing foreign substances in the cleaning liquid. A cleaning device with a foreign substance removing device is described. This apparatus has a flow path in which the cleaning liquid passes through the cleaning tank, the pump, the degassing tank, and the filter in this order and returns to the cleaning tank. However, in this apparatus, since the cleaning liquid that passes through the pump has not yet passed through the filter and contains foreign substances, the pump may be damaged due to the influence of the foreign substances.
If the filter is provided on the upstream side of the pump, the failure of the pump due to foreign matter can be prevented. However, in that case, since the pump must suck the liquid to be treated against the resistance of the filter, it is necessary to use a pump having a large suction force, which increases the cost.

On the other hand, Patent Literature 2 describes a cleaning tank, a deaeration tank that stores the cleaning liquid and degass the inside by depressurizing the inside, and a cleaning device with a deaerator equipped with an ejector used for the depressurization. ing. Here, the deaeration tank is provided such that the lower limit of the liquid level of the cleaning liquid stored therein is higher than the upper limit of the liquid level of the cleaning tank. Further, this apparatus has a flow path that returns from the cleaning tank to the cleaning tank through the deaeration tank. Note that this apparatus is not provided with an apparatus for removing foreign substances in the cleaning liquid.
In this apparatus, first, the inside of the deaeration tank is decompressed using an ejector, thereby introducing the cleaning liquid in the cleaning tank into the deaeration tank. When the cleaning liquid in the deaeration tank reaches a predetermined amount, the inside of the deaeration tank is opened to atmospheric pressure. At this time, since the liquid level in the deaeration tank is higher than the liquid level in the cleaning tank, the cleaning liquid in the deaeration tank is returned to the cleaning tank. Although this apparatus does not remove foreign matter, there is no pump in the flow path, so there is no problem of pump failure due to the influence of foreign matter.
However, in this apparatus, since the cleaning liquid is exposed to the atmosphere when returning the cleaning liquid from the deaeration tank to the cleaning tank, there arises a problem that gas is mixed into the cleaning liquid again. Moreover, since the deaeration process is not performed during the return, there is a disadvantage that the efficiency of the deaeration is low.

JP-A-6-151403 ([0011] to [0014], FIG. 1) Japanese Patent Laid-Open No. 6-071239 ([0032] to [0035], FIG. 1)

  The problem to be solved by the present invention is that the liquid to be treated can be efficiently degassed and foreign matters in the liquid to be treated can be removed, thereby preventing the pump from being broken. Another object is to provide a foreign matter removing apparatus.

In order to solve the above problems, the deaeration and foreign matter removal apparatus according to the present invention is a deaeration and foreign matter removal apparatus that removes foreign matter in a liquid to be treated while degassing a liquid to be treated.
a) A liquid storage tank for storing the liquid to be processed;
b) a degassing tank for degassing the liquid to be treated by introducing the liquid to be treated and depressurizing the inside;
c) an ejector for decompressing the inside of the deaeration tank;
d) A first flow path for feeding a liquid to be treated from the liquid tank to be treated to the deaeration tank and a second flow path for returning the liquid to be treated from the deaeration tank to the liquid tank to be treated. A treatment liquid circulation channel;
e) an apparatus for filtering a liquid to be treated provided in the first flow path;
f) a liquid feed pump provided in the second flow path, capable of sucking the liquid to be treated from the deaeration tank against pressure reduction by the ejector;
The liquid to be processed is fed from the liquid storage tank to the degassing tank by depressurizing the inside of the degassing tank using the ejector, and from the degassing tank to the liquid storage tank to be processed. Liquid feeding is performed by using the liquid feeding pump .

This deaeration and foreign matter removal device further includes
An operating liquid storage tank for storing an operating liquid for operating the ejector;
A working fluid circulation channel that returns from the working fluid reservoir to the working fluid reservoir via an ejector;
A working fluid circulation pump provided in the working fluid circulation channel;
A working liquid replenishing flow path connecting the second flow path and the working liquid storage tank;
A liquid replenishment control unit that supplies the liquid to be treated from the liquid replenishment channel to the working liquid storage tank as the working liquid when the working liquid in the working liquid storage tank becomes a predetermined remaining amount or less;
An operating fluid circulation device can be provided.

Embodiments and effects of the invention

  In the degassing / foreign substance removing apparatus according to the present invention, the liquid to be processed is from the liquid storage tank to the first flow path (and the filtration device in the middle), the degassing tank, and the second flow path (and in the middle). It flows through the liquid circulation path to be processed and returns to the liquid storage tank through the liquid feed pump. In the meantime, the foreign substance removal process is performed in the filtration device, and the deaeration process is performed in the deaeration tank.

  The liquid to be processed is reduced from the liquid tank to be processed to the deaeration tank by depressurizing the inside of the deaeration tank using an ejector, and from the deaeration tank to the liquid storage tank to be processed by using a liquid feed pump, The liquid is sent. A liquid feed pump having a capacity capable of sucking the liquid to be processed from the deaeration tank decompressed by the ejector is used. Since both the ejector and the liquid feed pump are inexpensive, the cost of the deaeration and foreign matter removing apparatus can be reduced. Since only the liquid to be processed after the foreign substance removal process is performed by the filtration device passes through the liquid feed pump, it is possible to prevent a failure due to the foreign substance. Further, in the degassing / foreign substance removing apparatus of the present invention, the liquid to be treated that has been degassed in the degassing tank is continuously taken out by the liquid feed pump, so that the degassing process is efficiently performed without interruption. be able to.

  The degassing / foreign substance removing apparatus of the present invention may further include a discharge pressure adjusting unit that adjusts the pressure of the liquid to be processed discharged downstream of the liquid feed pump. By adjusting the discharge pressure, the liquid to be treated can be prevented from being sent out from the deaeration tank without being sufficiently deaerated. The magnitude of the discharge pressure can be obtained by a preliminary experiment.

  The operating fluid circulation device is a device for operating the ejector. In this working liquid circulation device, when the working liquid in the working liquid storage tank becomes a predetermined amount or less, a part of the liquid to be treated is taken out from the second flow path, and the working liquid is taken out from the liquid replenishing flow path. By supplying it to the storage tank, the liquid to be treated is replenished as a working liquid. Here, since the liquid to be treated taken out from the second flow path is the liquid after the foreign matters have been removed, the working liquid circulation pump for circulating the working liquid does not break down due to the foreign matters. By using this working fluid circulation device, the working fluid can be automatically replenished even if the working fluid is reduced by evaporation or the like.

An embodiment of the deaeration and foreign matter removing apparatus according to the present invention will be described with reference to FIG. This apparatus is for performing deaeration processing and foreign matter removal processing of the cleaning liquid (processing liquid) stored in the processing liquid storage tank 11. In FIG. 1, the liquid flow path is indicated by a bold line, and the gas flow path is indicated by a double line.
Near the bottom of the liquid storage tank 11 to be processed, a suction port 111 for taking out the liquid to be processed inside, and a liquid to be processed after deaeration and foreign matter removal processing are returned to the liquid storage tank 11 to be processed. The discharge ports 112 are arranged so as to face each other. The suction port 111 is connected to the inlet of the filter 12 for removing foreign matter, and the outlet of the filter 12 is connected to the inlet of the deaeration tank 13. The outlet of the deaeration tank 13 is connected to a liquid feed pump 14. A discharge pressure adjusting unit 15 including a pressure adjusting valve 151, a pressure gauge 152, and a flow meter 153 is provided on the outlet side of the liquid feed pump 14. The outlet side of the discharge pressure adjusting unit 15 is branched into a delivery pipe 161 connected to the discharge port 112 in the treated liquid storage tank 11 and a reflux pipe 162 connected to the deaeration tank 13. A delivery valve 171 and a reflux valve 172 are connected to the reflux pipe 162 side.

  The deaeration tank 13 is connected to an ejector 21 via a check valve 18. The ejector 21 is provided in a working liquid circulation device 20 described later, and sucks the gas in the deaeration tank 13 when the working liquid passes through. A ball tap 131 is provided at the inlet of the deaeration tank 13 to adjust the liquid level of the liquid to be treated in the deaeration tank 13 to a predetermined height.

The operation of the deaeration and foreign matter removal apparatus of this embodiment will be described. First, as a preparation stage, the liquid to be treated is stored in the deaeration tank 13 as follows.
The gas in the deaeration tank 13 is sucked by the ejector 21 by operating the working liquid circulation device 20 as will be described later. Thereby, the liquid to be processed in the liquid storage tank 11 to be processed passes through the filter from the suction port 111 and is introduced into the deaeration tank 13. When the liquid level of the liquid to be processed in the degassing tank 13 reaches a predetermined height, the inlet of the degassing tank 13 is closed by the operation of the ball tap 131, and the inflow of the liquid to be processed into the degassing tank 13 is Stop temporarily. Further, by closing the deaeration suction valve 132 provided between the deaeration tank 13 and the check valve 18 and opening the leak valve 133 provided in the deaeration tank 13, the pressure in the deaeration tank 13 is increased. Return to atmospheric pressure.

  Next, with the delivery valve 171 closed, the reflux valve 172 is opened, and the liquid feed pump 14 is operated. And the discharge pressure of the to-be-processed liquid discharged from the liquid feeding pump 14 is adjusted by changing the opening degree of the pressure adjustment valve 151, confirming the pointer | guide of the pressure gauge 152. FIG. In this embodiment, the discharge pressure was set to 0.15 MPa, which is slightly larger than 0.10 MPa, which is a decrease in pressure by the ejector.

Next, the leak valve 133 is closed and the deaeration suction valve 132 is opened, and the reflux valve 172 is closed and the delivery valve 171 is opened. Thereby, the inside of the deaeration tank 13 is decompressed by the ejector 21, and the processing liquid is deaerated. The liquid to be treated is introduced into the deaeration tank 13 from the liquid tank 11 to be treated through the filter 12 for decompression by the ejector 21 and discharged from the deaeration tank 13 by the liquid feed pump 14. It is returned to the processing liquid storage tank 11. At that time, in the liquid storage tank 11, the liquid to be processed is discharged from the discharge port 112 toward the suction port 111 opposed thereto, so that foreign matter settled on the bottom of the liquid storage tank 11 is sucked out. Since it moves to 111 side, the efficiency of the foreign material removal from the to-be-processed liquid storage tank 11 further increases.
In this way, the liquid to be treated circulates in the flow path passing through the filter 12 and the deaeration tank 13, and foreign substances in the liquid to be treated are removed in the filter 12 and a deaeration process is performed in the deaeration tank 13.

  By the operation of the ejector 21 and the liquid feed pump 14, the liquid to be processed is continuously supplied and discharged in the deaeration tank 13. Therefore, the deaeration process is not interrupted, and the efficiency of the deaeration process is high. Further, since the discharge pressure of the liquid to be processed discharged from the liquid feed pump 14 is set by the discharge pressure adjusting unit 15 as described above, the liquid to be processed is sent out from the deaeration tank 13 without being sufficiently deaerated. Can be prevented.

  Next, the working liquid circulation device 20 will be described. The working liquid circulation device 20 is provided with an ejector 21, a working liquid storage tank 22, and a working liquid circulation pump 23 in a working liquid circulation channel 24. By operating the working liquid circulation pump 23 to circulate the working liquid through the working liquid circulation flow path 24, the working liquid passes through the ejector 21, whereby the ejector 21 causes the gas in the deaeration tank 13 to pass through. Suction. The working liquid is the same as the liquid to be treated.

  The working liquid storage tank 22 is provided with a working liquid replenishment pipe 25 that connects the working liquid storage tank 22 and the delivery pipe 161, and a working liquid ball tap 26 is provided in the working liquid storage tank 22. ing. Therefore, even if the working liquid decreases due to evaporation or the like of the working liquid, the working liquid ball tap 26 operates, and the liquid to be processed flowing in the delivery pipe 161 is automatically used as the working liquid. Refilled inside.

The schematic block diagram which shows one Example of the deaeration and foreign material removal apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Liquid storage tank 111 ... Suction port 112 ... Discharge port 12 ... Filter 13 ... Deaeration tank 131 ... Ball tap 132 ... Deaeration suction valve 133 ... Leak valve 14 ... Liquid feed pump 15 ... Discharge pressure adjustment part 151 ... Pressure Adjustment valve 152 ... pressure gauge 153 ... flow meter 161 ... delivery pipe 162 ... reflux pipe 171 ... delivery valve 172 ... reflux valve 18 ... check valve 20 ... operating liquid circulation device 21 ... ejector 22 ... operating liquid storage tank 23 ... Operating liquid circulation pump 24 ... Operating liquid circulation flow path 25 ... Operating liquid replenishment pipe 26 ... Operating liquid ball tap

Claims (3)

In the deaeration and foreign matter removing apparatus for removing the foreign matter in the liquid to be treated while degassing the liquid to be treated,
a) A liquid storage tank for storing the liquid to be processed;
b) a degassing tank for degassing the liquid to be treated by introducing the liquid to be treated and depressurizing the inside;
c) an ejector for decompressing the inside of the deaeration tank;
d) A first flow path for feeding a liquid to be treated from the liquid tank to be treated to the deaeration tank and a second flow path for returning the liquid to be treated from the deaeration tank to the liquid tank to be treated. A treatment liquid circulation channel;
e) an apparatus for filtering a liquid to be treated provided in the first flow path;
f) a liquid feed pump provided in the second flow path, capable of sucking the liquid to be treated from the deaeration tank against pressure reduction by the ejector;
The liquid to be processed is fed from the liquid storage tank to the degassing tank by depressurizing the inside of the degassing tank using the ejector, and from the degassing tank to the liquid storage tank to be processed. A degassing / foreign matter removing apparatus, wherein liquid is fed by using the liquid feeding pump .   The degassing / foreign matter removing apparatus according to claim 1, further comprising a discharge pressure adjusting unit that adjusts the pressure of the liquid to be processed discharged downstream of the liquid feed pump. An operating liquid storage tank for storing an operating liquid for operating the ejector;
A working fluid circulation channel that returns from the working fluid reservoir to the working fluid reservoir via an ejector;
A working fluid circulation pump provided in the working fluid circulation channel;
A working liquid replenishing flow path connecting the second flow path and the working liquid storage tank;
A liquid replenishment control unit that supplies the liquid to be treated from the liquid replenishment channel to the working liquid storage tank as the working liquid when the working liquid in the working liquid storage tank becomes a predetermined remaining amount or less;
The degassing / foreign matter removing device according to claim 1, further comprising a working fluid circulation device.

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