JPH11216304A - System for removing foam generated in aqueous solution system or water system under slight gravity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foam removing system capable of reliably removing foams from an aqueous solution or a water under a slight gravity and suppressing foam generation. SOLUTION: This foam removing system comprises two systems: one is a foam detecting and eliminating system for detecting and eliminating foams in a liquid (an aqueous solution or water) and the other is a foam pressurizing and dissolving and degassing system for degassing a liquid in which foams are dissolved by applying pressure. The foam detecting and eliminating system comprises a foam detector D1 for detecting foams in a liquid, flow route switching valves V1, V2 for discharging foams to outside of the system by switching the liquid flow routes at the time when foams are detected, and a control apparatus for controlling these components. The foam pressurizing and dissolving and degassing system comprises a high pressure pump PH for pressurizing and sending a liquid, a foam dissolving tank B for dissolving foams in the liquid under pressure, a capillary tube RP and a pressure decrease adjusting valve V5 for adjusting pressure decrease of the liquid, and an on-line degassing apparatus DG for degassing the resultant liquid in which foams are dissolved by a degassing membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bubble removing system, and more particularly, to an experiment in which bubbles are not mixed in an aqueous solution or water under the microgravity of the universe. The present invention relates to a bubble removal system for performing a degassing process.

[0002]

2. Description of the Related Art In a conventional electrophoresis system, a bubble removal system using a porous membrane such as Gore-Tex (trade name) is installed. It was used to remove air bubbles. This air bubble removing device manually removes air bubbles by using a syringe or the like, and cannot detect whether or not air bubbles have been mixed and cannot confirm whether or not air bubbles have been successfully removed. In addition, in the electrophoresis tank, a voltage of several hundred volts is applied to the buffer solution during analysis, so that Joule heat is generated and the temperature of the buffer solution increases, and at this time, a sufficiently degassed buffer solution must be used. During the analysis, the dissolved gas was vaporized and bubbles were generated, which hindered the experiment. In the above-described bubble removing device, it was impossible to degas dissolved gas from the buffer solution.

[0003] Under microgravity, gas-liquid separation using gravity cannot be performed sufficiently. Therefore, a technique for separating bubbles using centrifugal force, electrostatic force, or electromagnetic force has been developed. There is also a method of separating gas and liquid using a mesh by utilizing the surface tension of air bubbles. However, none of the methods can degas dissolved gas in the aqueous solution.

[0004] As a method of degassing a dissolved gas in an aqueous solution, a method of bubbling with an inert gas such as argon or a gas having a low solubility on the ground, or a method of degassing by applying physical energy such as ultrasonic waves during heating is used. However, such a method cannot be applied because gas-liquid separation cannot be performed under microgravity. In addition, as an on-line deaerator conventionally used in liquid chromatography,
In some cases, an aqueous solution is passed through the inside of a cylindrical Teflon (trade name) or silicon film, and the outside of the film is depressurized to degas dissolved gas. This method is considered to be applicable to microgravity conditions because gas-liquid separation is not required. However,
In such an online deaerator, when large bubbles pass through the inside of the membrane, it is expected that the bubbles cannot be sufficiently removed during the time when the aqueous solution passes through the inside of the membrane. Therefore, it is necessary to sufficiently dissolve bubbles in the aqueous solution before introducing the aqueous solution into the film.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and (1) a system for detecting and automatically discharging air bubbles mixed into an aqueous solution or water; ) Bubbles are dissolved in aqueous solution or water, dissolved gas components are removed, and the gas amount is controlled below the saturated dissolved gas concentration at the operating temperature and pressure. Removal of bubbles from aqueous solution or water under microgravity conditions by a system that suppresses the generation of bubbles at the time, a system that combines (1) and (2), or a system that uses (2) alone The purpose of the present invention is to provide an air bubble removing system capable of reliably suppressing air bubbles.

[0006]

According to the first aspect of the present invention, there is provided an air bubble detection and elimination system for detecting air bubbles contained in an aqueous solution such as a buffer solution and an eluent or water and eliminating the air bubbles, and an air bubble detection system. The aqueous solution or water subjected to the action of the elimination system is pressurized, the air bubbles remaining after passing through the air bubble detection and elimination system are dissolved in the aqueous solution or water, and the remaining air bubbles obtained are removed from the aqueous solution or water in which the dissolved air bubbles are dissolved. A bubble pressure dissolving and degassing system for removing air, wherein the bubble detection and elimination system detects bubbles mixed in the aqueous solution or water, wherein the bubble detection and elimination system detects bubbles mixed in the aqueous solution or water. An air bubble detector, a flow path switching valve that switches the flow path of the aqueous solution or water when the air bubble detector detects air bubbles, and eliminates the detected air bubbles, and the flow path switching. A control device for controlling a valve, wherein the bubble pressure dissolution / degassing system comprises a high-pressure pump for pressurizing and sending the aqueous solution or water, and dissolving the remaining bubbles in the aqueous solution or water under pressure. A bubble dissolving tank, a decompression unit for depressurizing the aqueous solution or water sent from the bubble dissolving tank, and an online deaerator for deaeration using a deaeration membrane from the aqueous solution or water passed through the depressurizing unit. It is possible to reliably remove air bubbles from an aqueous solution or water and suppress the generation of air bubbles under microgravity conditions on orbit, thereby removing air bubbles from an aqueous solution or water and reducing the amount of dissolved gas. It can be applied to experiments such as electrophoresis that require reduction, and can increase the success rate of experiments.

According to a second aspect of the present invention, there is provided a high-pressure pump for pressurizing and sending an aqueous solution or water such as a buffer solution or an eluent mixed with air bubbles, and a bubble dissolving tank for dissolving the air bubbles in the aqueous solution or water under pressure. And a decompression unit for decompressing the aqueous solution or water sent from the bubble dissolving tank, and an on-line deaerator for degassing the aqueous solution or water passing through the decompression unit using a deaeration film. As a feature, the system can be simplified as a space experiment system, and it is possible to reliably remove bubbles from aqueous solution or water under microgravity conditions in orbit and to suppress the generation of bubbles. Alternatively, the present invention can be applied to an experiment such as electrophoresis that requires removal of bubbles from water and a reduction in the amount of dissolved gas, thereby increasing the success rate of the experiment.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, a silicon film is used as the deaeration film, so that a stable deaeration performance is obtained without being affected by the flow rate. It was made.

A fourth aspect of the present invention is characterized in that in any one of the first to third aspects of the present invention, a capillary tube for reducing pressure and a pressure reducing valve are used as the pressure reducing means, and the bubbles are pressurized and dissolved. A specific configuration of the pressure reducing means for effectively operating the degassing system is provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a bubble removing system according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a bubble removal system according to the present invention. In the drawing, B is a bubble dissolving tank, D1 is a bubble detector, D2 is a dissolved oxygen meter, and DG is an online deaerator. , P1, P2 are pressure gauges, PH is a high pressure pump, RP is a capillary tube, T is a thermometer, V1,
V2, V3 and V4 are solenoid two-way valves (flow path switching valves), V
Reference numeral 5 denotes a pressure reducing valve, and VI denotes a bubble injection device. The bubble removal system of the present embodiment includes a bubble detection and elimination system that detects and discharges bubbles mixed in from the QD when the solution tank is attached and detached, and dissolves bubbles remaining under the bubble detection and elimination system under pressure to dissolve the bubbles. It is configured by combining two systems of a bubble pressure dissolution degassing system for degassing a gas. It should be noted that one configuration of the present invention constitutes the above-described bubble pressure dissolution / degassing system alone. In this case, the operation of the bubble pressure dissolution / degassing system in the system of the embodiment shown in FIG. The operation is the same as that of the above-mentioned system, and the corresponding portions are the disclosures of both embodiments.

The bubble detection and elimination system includes a bubble detector D1.
And two-way valves V1, V2, V3 for switching the flow path
And a control device. The bubble pressure dissolving and deaeration system comprises a high pressure pump PH, a bubble dissolving tank B, a capillary tube RP, a pressure reducing valve V5 for pressure reduction, and online degassing. And a device DG.

The operation of each of the above two systems will be described below. 1. Bubble detection and exclusion system
A light transmission type bubble detector D1 is installed in that part. Further, two-way solenoid valves V1, V2, V3 for controlling the flow path and a control device for controlling these two-way solenoid valves are provided downstream of the bubble detector D1. When air bubbles are detected by the air bubble detector D1, the control device receives this signal and opens and closes the necessary one of the electromagnetic two-way valves V1, V2, and V3 to open and close the flow of the aqueous solution (or water). The path is changed to automatically discharge air bubbles out of the experimental system. If no bubbles are detected, the aqueous solution is sent to a bubble pressure dissolution and deaeration system installed downstream.

2. Bubble pressure dissolution and deaeration system For the bubbles that cannot be completely removed by the above-described bubble detection and elimination system, the bubbles are dissolved and deaerated by the following configuration. First, the aqueous solution containing bubbles is sent to the bubble dissolving tank B by the high-pressure pump PH. Downstream of the bubble dissolving tank B, a capillary tube RP and a pressure reducing valve V5 are installed to keep the pressure in the bubble dissolving tank B in a pressurized state and simultaneously operate the pressure at the inlet of the online deaerator DG. Keep within the condition range.
The aqueous solution introduced into the bubble dissolving tank B in a pressurized state increases the solubility of the gas by pressurization, and the remaining bubbles in the aqueous solution are
It dissolves in the aqueous solution in the bubble dissolving tank B having a sufficient capacity.
In the on-line deaerator DG, an aqueous solution is caused to flow inside a cylindrical film, and at this time, the outside of the film is depressurized, thereby degassing the dissolved gas. If necessary, the degassed aqueous solution is circulated in the system to reduce the amount of gas in the entire system.

Next, as a simulation for confirming the performance of the air bubble removing system according to the present invention, the following experiment was conducted using a test loop shown in FIG. 1. Checking the performance of the bubble detection and elimination system To check the performance of the bubble detection and elimination system, install a bubble injecting device VI, inject air into the aqueous solution, and measure the amount of air discharged out of the system by the bubble detection and elimination system. did. At this time, the distance from the bubble injection device VI to the bubble detector D1 was set to 20 cm, the distance from the bubble detector D1 to the valve group (the electromagnetic two-way valves V1, V2, and V3) was set to 5 cm. . Air injection volume is 1m
l, 0.5 ml, and 0.1 ml. As a result of the measurement, the amount of air discharged out of the system was 90% or more of the initial injection amount. That is, even if bubbles of 1 ml at the worst are mixed, the bubbles flowing to the system installed on the downstream side are reduced to 0.1 m.
l or less.

2. Confirmation of Characteristics of Degassing Film An online degassing device DG using the degassing film was installed, and the degassing performance characteristics according to the flow rate of the aqueous solution were evaluated. Commercially available degassing membranes exhibit a predetermined performance within the operating flow rate range, but when applied to the system of the present invention, their degassing performance is expected to change, so they are stable over a wide flow rate range. It is necessary to select a degassing membrane that can obtain degassing efficiency. Here, the flow rate range was 5 to 20 ml, and two types of silicon material films were prepared and compared with commercially available Teflon films. FIG. 2 is a graph showing the relationship between the flow rate of an aqueous solution by a degassing membrane material and oxygen permeability. The oxygen transmission rate was derived from the following equation. Oxygen permeability = ((inlet oxygen concentration-outlet oxygen concentration) / inlet oxygen concentration) / film area As a result, the silicon film showed stable deaeration characteristics in the flow rate range tested.

3. Confirmation of bubble dissolving effect at the time of pressurization Using a bubble dissolving tank B having a capacity of 25 ml, 1 ml of air was injected to perform a deaeration circulation operation of the aqueous solution. A baffle plate was provided inside the bubble dissolving tank B in order to accelerate the dissolution of bubbles, and a structure for ensuring a flow rate around the bubbles was adopted. This was compared with a case where no baffle plate was provided. The operating pressure conditions in the bubble dissolution tank B were changed, and the bubble dissolution time under each pressure condition was measured. FIG. 3 is a graph showing the relationship between the pressure depending on the solution flow rate and the bubble dissolution time. FIG. 3 (A) shows the characteristics when the baffle plate is installed and FIG. 3 (B) shows the characteristics when the baffle plate is not installed. As a result, during pressurization, bubbles disappear in 1/4 to 1/3 of the time during non-pressurization, and the bubble dissolution time can be significantly reduced. Also,
In the case where the baffle plate was installed in the dissolution tank and in the case where it was not installed, air bubbles disappeared in about 1/3 of the time when the baffle plate was installed compared to the case where no baffle plate was installed. As a result, as compared with a non-pressurized state in which no baffle plate is provided, the time until the bubble disappears can be reduced to about 1/10 by installing the baffle plate and applying pressure. In an actual space experiment, in order to secure the flow rate around the bubbles and obtain the same effect as the baffle plate, trap the bubbles with a mesh and apply the water flow emitted from the nozzle directly to the bubbles. It may be.

4. Dissolved oxygen concentration downstream of the degassing membrane In the ground test loop, the oxygen concentration downstream of the on-line degassing device DG was measured and was stable at around 2 ppm. Even if 1 ml of air bubbles were introduced into the dissolution tank, it was around 3 ppm It rises for a while, but then converges to 2 ppm. The oxygen concentration of 2 ppm corresponds to the saturated dissolved gas amount at a water temperature of 80 ° C., and indicates that no bubbles are generated at the level of the temperature rise in the electrophoresis tank in the actual operation. In the conventional bubble removing device installed in the existing electrophoresis system, the dissolved gas amount does not fall below the saturation solubility of the solution temperature during operation, and a remarkable effect is obtained by the present invention.

[0018]

According to the first aspect of the present invention, the bubble detection and elimination system can automate the detection and discharge of the bubbles, and can reduce the operation of removing the bubbles which has been conventionally performed by the astronaut when the bubbles are mixed. In addition, the installation of the bubble pressure dissolution and deaeration system can provide a deaeration function that has not been provided on orbit until now. By configuring these systems in combination, it is possible to reliably remove bubbles from the aqueous solution or water and suppress the generation of bubbles under microgravity conditions on the orbit, thereby removing bubbles from the aqueous solution or water, and The present invention can be applied to an experiment such as electrophoresis that requires a reduction in the amount of dissolved gas, and the success rate of the experiment can be increased. In addition, the degassing process on the ground, which is performed as a pretreatment of the aqueous solution or water used on orbit, can be simplified.

According to the second aspect of the present invention, a degassing function which has not been provided on the orbit can be obtained, and it is particularly suitable for a case where the predicted bubbles are small. With this system, it is possible to reliably remove bubbles from aqueous solution or water and suppress the generation of bubbles under microgravity conditions on the orbit, so it is necessary to remove bubbles from aqueous solution or water and reduce the amount of dissolved gas. And the success rate of the experiment can be increased. Also,
The deaeration process on the ground performed as a pretreatment of the aqueous solution or water used on orbit can be simplified. further,
It is possible to realize weight reduction and suppression of complexity of the experimental system, which are important issues in space experiments, and to construct an appropriate experimental system according to the purpose.

Effect of Claim 3 In addition to the effect of Claim 1 or 2, the use of a silicon film as the degassing film provides a stable degassing performance without being affected by the flow rate.

Effect of Claim 4 In addition to the effect of any one of Claims 1 to 3, a specific structure of a decompression means for effectively functioning a system for dissolving and degassing by pressurizing bubbles is provided. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a bubble removal system according to the present invention.

FIG. 2 is a graph showing a relationship between a solution flow rate and oxygen permeability by a degassing film material.

FIG. 3 is a graph showing the relationship between the pressure depending on the solution flow rate and the bubble dissolution time.

[Explanation of symbols]

B: bubble dissolving tank, D1: bubble detector, D2: dissolved oxygen meter, DG: online deaerator, P1, P2: pressure gauge,
PH: High pressure pump, RP: Capillary tube, T:
Thermometer, V1, V2, V3, V4: electromagnetic two-way valve (flow path switching valve), V5: pressure reducing valve, VI: bubble injection device.

 ──────────────────────────────────────────────────続 き Continued on the front page (74) One of the above-mentioned agents Attorney Akinaka Takano (one outsider) (72) Inventor Akitoshi Yokota 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa JGC Yokohama, Japan In-house (72) Inventor Norio Takeuchi 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa Prefecture JGC Corporation Yokohama Head Office (72) Inventor Akira Hasegawa 2205 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki Prefecture Inside the Development Center (72) Tatsuya Sato 2-1-1, Sengen, Tsukuba, Ibaraki Pref. Space Development Corporation Tsukuba Space Center (72) Inventor Masatoshi Tsuji 3-30-16 Nishiwaseda, Shinjuku-ku, Tokyo Foundation Space Environment Promotion Center

Claims (4)

[Claims] 1. An air bubble detection and elimination system for detecting air bubbles mixed in an aqueous solution such as a buffer solution and an eluent or water and eliminating the air bubbles, and the aqueous solution or water subjected to the action of the air bubble detection and elimination system Pressurize, and dissolve remaining air bubbles after passing through the air bubble detection and elimination system in the aqueous solution or water, and deaeration from the aqueous solution or water in which the obtained residual air bubbles are dissolved. A bubble removal system generated in an aqueous solution system or water system under microgravity, wherein the bubble detection and elimination system includes a bubble detector that detects bubbles mixed in the aqueous solution or water, and the bubble detector. A switching device that switches a flow path of the aqueous solution or water when bubbles are detected, and a flow path switching valve that eliminates the detected bubbles; and a control device that controls the flow path switching valve. The bubble pressure dissolving and degassing system includes a high-pressure pump that pressurizes and sends the aqueous solution or water, a bubble dissolving tank that dissolves the remaining bubbles in the aqueous solution or water under pressure, and a bubble dissolving tank that dispenses from the bubble dissolving tank. Decompression means for decompressing the aqueous solution or water, and an on-line deaerator for degassing the aqueous solution or water that has passed through the decompression means using a degassing membrane under microgravity, A system for removing bubbles generated in aqueous or aqueous systems. 2. A high-pressure pump for pressurizing and sending an aqueous solution or water such as a buffer solution or an eluent mixed with air bubbles, a bubble dissolving tank for dissolving the air bubbles in the aqueous solution or water under pressure,
A decompression unit for decompressing the aqueous solution or water sent from the bubble dissolving tank, and an on-line deaerator for degassing the aqueous solution or water passing through the decompression unit using a deaeration film. A bubble removal system generated in an aqueous or aqueous system under microgravity. 3. The system for removing bubbles generated in an aqueous or aqueous system under microgravity according to claim 1, wherein a silicon film is used as the degassing film. 4. A bubble generated in an aqueous system or an aqueous system under microgravity according to claim 1, wherein a capillary tube for reducing pressure and a pressure reducing valve are used as said pressure reducing means. Removal system.