JP3275978B2 - Gas-liquid separation 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 gas-liquid separator for degassing a liquid to be treated or a solute thereof by physical means, and separating and recovering the gas and the liquid after the gas has been degassed. Things.

[0002]

2. Description of the Related Art There have been proposed many devices for physically or chemically separating and removing dissolved substances contained in a liquid to be treated. For example, filtration and separation devices using activated carbon, hollow fibers and the like to remove chlorine gas and other impurities contained in tap water are well known.
These filtration and separation devices are characterized in that they are filtered and separated in a state in which chlorine gas is dissolved in a water solvent. If the solution to be treated is sent to the filtration and separation device, water as a treatment liquid is obtained. Things.

However, in this type of filtration and separation equipment, it is necessary to periodically replace activated carbon and hollow cotton yarn.
There was a problem that costs increased in the long term. There is also a problem that components to be filtered and separated cannot be taken out and used. So, without using filter media,
Many gas-liquid separation devices have been proposed which generate a gas component from a liquid to be treated to separate the liquid to be treated into a specific gas component and a residual solution component.

For example, as a first means for generating a gas component from a liquid to be treated, a container containing the liquid to be treated is depressurized by a vacuum pump and placed under a pressure condition lower than the saturated vapor pressure of the gas component. There is known a gas-liquid separation device that separates a gas component and a liquid component by realizing a state in which a gas component in a liquid to be processed is easily evaporated. As a second means, the solute (gas component) in the liquid to be treated is diffused and dissolved in the solvent by bringing the liquid to be treated into contact with the solvent via the semipermeable membrane, so that the solute (gas) in the liquid to be treated is There is known a gas-liquid separator in which only the solvent is removed by removing the component.

Further, as a third means, there is known a gas-liquid separation apparatus which lowers the solubility of a solute (gas component) contained in a liquid to be treated by heating the liquid to be treated and vaporizes and separates the gas component. Have been. Further, as a fourth means, by utilizing the difference between the boiling point of the solute (gas component) in the liquid to be treated and the boiling point of the solvent (liquid component), the liquid to be treated is distilled off by volatilization to separate the solvent and the solute from each other. There is known a gas-liquid separation device for performing vaporization separation. As a fifth means, there is known a gas-liquid separation apparatus in which a liquid to be treated is filled in a catalyst tank which is open to the atmosphere, and the mixture is stirred to promote gas-liquid separation. Have been.

[0006]

However, the conventional gas-liquid separator has the following problems. That is, a gas-liquid separation device that separates gas and liquid by placing the liquid under treatment under reduced pressure is a solute (gas component) at room temperature even when used for a liquid containing a solute having a high boiling point.
However, there is a problem in that the use of the liquid to be treated containing a solute having a low boiling point cannot be promoted, and the use thereof is limited. In addition, since a vacuum pump or the like must be provided as a part of the device, the size of the device is increased. When the solute in the liquid to be treated is a corrosive gas, the vacuum pump or the like is corroded and gas-liquid separation is performed. The product life of the device may be significantly shortened,
Further, there is a problem that noise and vibration are generated with the operation of the vacuum pump and the like.

In a gas-liquid separation device for removing solutes in a liquid to be treated by using a membrane such as a semipermeable membrane, the gas-liquid separation time depends on the diffusion time (diffusion rate) of the solute in the solvent. However, there is a problem that it takes a long time to complete the gas-liquid separation. This problem is usually attributable to the slow diffusion rate of the solute into the solvent.However, the diffusion rate is a property value resulting from the interaction between the solvent and the solute, and it is not possible to greatly accelerate this. It is difficult, and it is necessary to increase the absolute diffusion amount by increasing the contact area between the solvent and the solute, and there is a problem that the apparatus becomes large.

Further, in a gas-liquid separation apparatus in which a liquid to be processed is simply heated by a heating means to separate a gas component and a liquid component, fine bubbles appearing in the liquid to be processed by heating are separated and recovered from the liquid component. However, there is a problem that the accuracy of separation is extremely poor unless some other separation and collection means is provided. Further, in a gas-liquid separation device that separates a liquid to be treated into a solute and a solution by distillation, a heating device is required to evaporate a desired gas component in the liquid to be treated, and the energy cost becomes extremely high. In addition, a distillation apparatus such as a distillation column must be provided, and the entire apparatus is significantly increased in size, and the equipment cost is increased.

In the gas-liquid separation apparatus using a catalyst tank, the gas-liquid separation operation is a continuous operation since the gas component in the liquid to be treated is a batch process waiting for release to the atmosphere. Is difficult to perform, and there is a problem that the processing ability is inferior. Further, even if the fine bubbles generated by decomposition do not readily deaerate from the solution and the solvent is taken out from the lower layer of the catalyst tank, separation from the solvent is difficult, and the gas-liquid separation accuracy is poor. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a gas-liquid separation apparatus for separating and recovering a gas component and a liquid component with high gas-liquid separation performance. In addition, a gas-liquid separation device that separates and recovers a gas component and a liquid component without changing the properties of the liquid to be treated, and that does not require higher energy costs, does not generate noise and vibration, and is excellent in space saving. The purpose is also to do.

[0011]

In order to achieve this object, a gas-liquid separation device according to the present invention is provided for supplying a liquid to be treated fed to a space partitioned by a porous wall through which a liquid can pass. Dissolved gas is physically separated from the liquid to be treated in the feed path (degassing)
A dissolved gas separation (degassing) means for causing the separated gas from which the dissolved gas is separated (degassed) and removed by the dissolved gas separation (degassing) means to be extracted from the porous wall to the outside of the system. That is, the gist of the invention.

Examples of the physical dissolved gas separation (degassing) means used at this time include a heating means and a vibration means. And, in the space, the liquid to be treated is
Pressure below the bubble point pressure of the porous wall
It is desirable to provide a pressure regulating valve for adjusting the pressure.

[0013]

According to the gas-liquid separation device of the present invention having the above configuration, the dissolved gas dissolved in the liquid to be treated is physically separated from the dissolved gas by heating means and vibration generating means provided in the feed path. The liquid to be treated is separated into a gas and a separated liquid from which the dissolved gas has been degassed.

The gas thus degassed and the degassed solution of the dissolved gas remain separated in a space partitioned by a porous wall through which only the liquid can pass at a bubble point pressure P or less. Will be fed. Then, only the degassed separated solution of the dissolved gas is extracted out of the system from the voids (pores) formed in the porous wall, and the degassed dissolved gas remains in the system and is removed. Become.

The bubble point pressure of the porous wall is obtained by immersing the porous wall in a liquid (for example, water), applying gas pressure from one side of the porous wall to push out the liquid in the pores, and from the other side to generate bubbles. Can be determined from the gas pressure at which the gas begins to appear (bubble point method). The bubble point pressure P is calculated by using the maximum pore diameter r of the porous wall, the surface tension γ of the liquid, the contact angle θ between the liquid and the porous wall, and the shape factor K of the pore, P = K · 4πγ · It is known that the relational expression of cos θ · 1 / r is approximately satisfied, and it is possible to estimate the range of the pore diameter according to the processing pressure from this equation.

For example, if the working pressure is set to ² kg / cm ² , the bubble point pressure P of the porous wall used must be at least higher than 2 kg / cm ² . Here, when the porous wall is an alumina ceramic porous body and the liquid to be treated is water, the surface tension of water is 73 dy.
ne / cm, the contact angle between water and alumina ceramic is 1
0, the pore shape coefficient of the porous alumina ceramic body is set to 0.
Assuming that 2, the maximum pore diameter r is 0.9 μm from the above relational expression.
m or less. Generally, the pore size distribution has a wide range. Therefore, it is preferable to select and use a porous body having a pore size taking this into consideration.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas-liquid separator D embodying the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing the overall schematic configuration of a gas-liquid separation device D according to the present invention. FIG. 2 is a degassing section V, a gas-liquid separation and recovery section of the gas-liquid separation device D shown in FIG. FIG. 3 is a sectional view showing S in detail, and FIG.
FIG. 4 is a diagram schematically showing a cross section of a porous tube constituting a gas-liquid separation and recovery unit.

As shown in FIG. 1, a gas-liquid separator D according to the present invention comprises a liquid supply pipe 10 for supplying a liquid to be treated,
A degassing unit V joined to the liquid supply pipe 10 to degas a gas component from the liquid to be treated, and a gas-liquid separator joined to the degassing unit V to separate and collect the degassed gas component and liquid component Recovery unit S and processing gas pipe 2 joined to gas-liquid separation and recovery unit S
0.

In the present embodiment, tap water is used as the liquid to be treated, and chlorine gas (Cl ₂ ) is degassed from the tap water as a gas component to obtain water (H ₂ O) as a liquid component. is there.

Next, each component will be described in detail with reference to FIG. In the vicinity of the joint 11 of the liquid supply pipe 10 to be treated,
A flow control valve 12 for adjusting the amount of tap water is formed, and a stainless pipe 13 constituting a deaeration section V is fitted into the joint section 11 so as to be included therein.
0 and the outer periphery 13a of the stainless steel tube 13 are hermetically connected by welding or the like.

The deaeration section V has a hollow stainless steel tube 13 having an outer diameter of 7.0 mm, an inner diameter of 5.0 mm, and a length of 300 mm through which tap water flows, and heats the tap water through the stainless steel tube 13. PTC (Positive Temperature Coeff), a heating means for degassing dissolved chlorine gas
icient) and a heating element 14. The PTC heating element 14 is attached to the outer periphery 13a of the stainless steel pipe 13 as an axis, and the stainless pipe 13 is configured to be longer than the PTC heating element 14 because it is joined to another member. . End 13 of stainless steel tube 13 opposite to end 13b joined to liquid supply pipe 10 to be treated
A porous tube 15 constituting the gas-liquid separation / collection section S is connected to c.

The gas-liquid separation and recovery section S is composed of a porous alumina tube 15 having an outer diameter of 7.0 mm, an inner diameter of 5.0 mm, and a length of 300 mm, and a bag tube 16 covering the same. The parts 15a and 16a are joined by welding or the like to the end part 13c of the stainless steel tube 13 constituting the degassing part V.

The bag tube 16 is formed of a glass material, and has through holes 17 at both ends 16a and 16b for allowing the porous tube 15 to pass therethrough. Also,
A receiving portion 16b for receiving water leaked from the outer wall surface 15b of the porous tube 15 is formed at the bottom of the bag tube 16, and the water dropped from the porous tube 15 is discharged as a treatment liquid. A discharge port 16c for supplying the processing liquid to the water tap N is connected to the discharge port 16c.

As shown in FIG. 3, the porous tube 15 has
A plurality of pores 19 are formed over the entire area of the tubular body, and the porous tubular body 15 is manufactured as follows. still,
FIG. 3 is a model diagram showing the porous tube body 15 in which the pores 19 are formed, and does not exemplify the actual state of the pores 19.

That is, each raw material was put into a mixer so that the mixing amount of 20 g of wollastonite, 30 g of talc, 20 g of methylcellulose, and 100 g of water was added to 1 kg of alumina powder having an average particle size of 5 μm, and kneaded well. The extruded product was used for an outer diameter of 7.7 mm and an inner diameter of 5.5.
A hollow raw tube of mm is manufactured.

After the raw tube is dried naturally, 1
By firing at 600 ° C. for about 3 hours, methylcellulose contained in the raw tube is decomposed and burned, wollastonite and talc act as sintering aids, and alumina particles are sintered. At this time, a porous tube 15 having many continuous ventilation holes 19 in which ventilation voids (continuous ventilation holes) 19 are formed three-dimensionally between the alumina particles is obtained.

The pores 19 formed in the porous tubular body 15
Has an average pore diameter of 0.8 μm, a porosity indicating the amount of pores 19 per unit area is 41%, and only the liquid to be treated (liquid) is permeated, and chlorine gas (gas) is The bubble point pressure which indicates the boundary pressure at which no permeation occurs is measured by the above-described bubble point method. As a result, the porous tube used in this example has a characteristic of 1.7 kg / cm ² .

As long as the gas- liquid separation operation is performed at an operating pressure equal to or lower than the bubble point pressure obtained as described above, chlorine gas (gas component) is not extracted to the outside of the porous tube. The processing gas pipe 20 is joined to the opposite end 15c of the porous tube body 15 by welding or the like at the end 15c opposite to the joint end 15a with the degassing section V, and the connection 20a of the processing gas pipe 20 is formed. Is formed in the vicinity of the pressure regulating valve 21 for adjusting the pressure in the pipe such as the porous pipe body 15. The processing gas pipe 20 is connected to the processing gas container T
It is connected to the.

Next, the operation of the gas-liquid separation device D will be described with reference to FIGS. When the flow control valve 12 is opened, the tap water starts flowing in the liquid supply pipe 10 and flows into the stainless pipe 13 constituting the deaeration section V. The stainless tube 13 is a stainless steel tube 13
About 120 ° C by the PTC heating element 14 wound around
, And the tap water flowing into it is immediately heated. When the tap water is heated, chlorine gas dissolved in the tap water starts to be degassed from the tap water. This utilizes the property that the solubility of the gas dissolved in the solution decreases as the temperature increases.

As described above, the chlorine gas and the remaining water degassed from the tap water in the degassing section V flow through the inside of the porous tube 15 constituting the gas-liquid separation and recovery section S, and Collected separately as gas or water. As shown in FIG. 3, the porous tube 15 used here transmits only the liquid component (water) and does not transmit the gas component (chlorine gas) when the operating pressure is at or below the bubble point pressure. It has pores 19.

Accordingly, chlorine gas, which is a gaseous component, remains inside the porous tube 15 without leaking to the outer wall surface 15b of the porous tube 15, and ends 15c of the porous tube 15
It flows to the pressure regulating valve 21 formed in the processing gas pipe 20 joined to the pressure regulating valve 21. The chlorine gas flowing to the pressure regulating valve 21 is stored in the processing gas container T via the processing gas pipe 20.

Here, as shown in FIG. 2, since the vent valve 21a is formed on the upper part of the pressure regulating valve 21, even in a gas-liquid mixed state, water is located in a lower layer, so that the pressure in the pipe is maintained. Only chlorine gas can be ventilated. Therefore, water as a liquid component permeates through the porous tube 15 and leaks to the outer wall surface 15b of the porous tube 15,
Further, even when the pressure inside the porous tube 15 fluctuates due to the release of chlorine gas, which is a gas component, the pressure inside the porous tube 15 is kept constant, and the gas-liquid separation operation is delayed. It is used to prevent and at the same time adjust the bubble point pressure P.

In order to keep the pressure inside the porous tube 15 in this manner, water, which is a solvent component of tap water from which chlorine gas has been degassed, leaks to the outer wall surface 15b. It is necessary to maintain the pressure inside the porous tube 15 higher than the pressure outside the porous tube 15 and to adjust the pressure inside the porous tube 15 so as not to exceed the bubble point pressure. Because.

On the other hand, the liquid component (water) from which the gas component has disappeared
If a pressure difference is generated between the inside of the porous tube 15 and the outside of the porous tube 15, the porous tube 15 can freely leak from the pores 19 to the outer wall surface 15 b of the porous tube 15. Body 15
The pressure difference between the outside and the inside causes the porous tube 1
5 leaks to the outside through the pores 19 formed. At this time, since the pore diameter is as small as about 0.8 μm and the pore path is formed in a complicated manner, impurities contained in the solvent component are also removed at the time of permeation. It can be used as disinfecting water.

As described above, the gas-liquid separation device D according to the present invention
Since the gas-liquid separation and recovery section S does not use any power device, no noise or vibration is generated. In the present embodiment, the degassing section V is provided independently of the gas-liquid separation and collection section S, and passes through the gas-liquid separation and collection section S in a state where the chlorine gas has been sufficiently degassed from the tap water. Accordingly, the separation accuracy is improved, and the chlorine gas and water can be separated with an extremely high separation rate.

Next, the gas-liquid separation performance using the gas-liquid separation device D according to the present invention will be described with reference to experimental results. This experiment was performed using the gas-liquid separation device D shown in FIG. 27 ppm
Using tap water, and applying it under a pressure of 1 kg / cm ²
By operating the flow control valve 12, 18 ml / min. The experiment was performed at a flow rate of. In addition, the stainless pipe of the deaeration section V
It is in a state of being heated to about 120 ° C. by the PTC heating element.

As a result of this experiment, the chlorine concentration of the treated water leaked to the outer wall surface 15b of the porous tube 15 and collected in the tray 16b formed at the bottom of the bag tube 16 is 0.1%.
01 ppm, and the amount of treated water obtained at this time is 17 ml / min. Met.

The result is obtained by the gas-liquid separation device D according to the present invention.
Means that the concentration of chlorine in tap water can be reduced by about 96%, and the flow rate of treated water is only about 5% lower than the flow rate of treated water. Therefore, the flow rate loss is small and it can sufficiently cope with actual use. In the present embodiment, the PTC heating element 14 is used as a means for degassing chlorine gas from tap water. However, an ultrasonic generator may be provided as a degassing means instead.

In general, it is known that, when a solution is irradiated with ultrasonic waves, gas components dissolved in the liquid to be treated are deaerated as fine bubbles, and if this deaeration means is used,
Even in the case of a thermovariable solution, a gas component and a liquid component can be separated and recovered without changing the chemical and physical properties. Further, since the gas-liquid separation device D according to the present invention has the porous tube 15 as the gas-liquid separation / collection unit S, fine bubbles mixed in the liquid to be treated by irradiation of ultrasonic waves can be surely removed. It can be separated.

In this case, in the gas-liquid separation device D according to the present invention, an ultrasonic vibrator is disposed inside the stainless steel tube 13, and the liquid to be processed flowing inside the stainless steel tube 13 is the supersonic vibrator. Contact with sonic vibrator. When a voltage is applied to the ultrasonic vibrator, ultrasonic vibration is applied to the liquid to be processed, and gas components are degassed from the liquid to be processed. Also, the ultrasonic vibrator is
It may be arranged in contact with the outside of the stainless steel tube 13.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments.
It can be easily inferred that various modifications and improvements can be made without departing from the spirit of the present invention. That is,
In the present embodiment, a PTC heating element is used as a heating means for degassing chlorine gas from tap water. However, it is sufficient that tap water existing inside the stainless steel pipe can be heated to degas chlorine gas. A heating element such as In this embodiment, the tap water is heated from the outside by the heating element wound around the stainless steel pipe. However, a heat pipe or the like may be provided in the stainless steel pipe to directly heat the tap water.

In this embodiment, a porous tube is used for gas-liquid separation and recovery. However, the present invention is not limited to this as long as it has a space structure having a porous wall. It may be a rectangular tube provided with. Further, in the present embodiment, a case is described in which chlorine gas is degassed using tap water as a liquid to be treated.
The method is not limited to this as long as the gas component can be degassed from the liquid to be treated by ultrasonic irradiation.

As the raw material of the porous tube, porous silica or zeolite may be used in addition to alumina as long as it is adjusted so as to obtain a desired pore diameter. There is no limit. Also, the molding method is not limited to the molding method used in the embodiment as long as a molding method according to the raw material is adopted.

In this embodiment, the case where the liquid to be treated flows inside the porous tube is described, but the liquid to be treated flows through the peripheral surface of the porous tube. The same result can be obtained even if the extract after gas degassing is collected in the porous tube.

[0045]

As is apparent from the above description, according to the gas-liquid separation device of the present invention, the liquid to be treated fed to the space partitioned by the porous wall through which the liquid can pass is: The gas is degassed by physical dissolved gas separation (degassing) means, and only the liquid portion excluding the degassed gas is separated and recovered through its porous wall. Alternatively, gas-liquid separation can be performed without being affected by the solute.

In particular, the gas component and the liquid component are separated and recovered with high separation accuracy without being affected by the fine bubbles existing in the liquid to be treated by the dissolved gas separating means such as a heating device and a vibration generating device. When the vibration generator is provided as a dissolved gas separation means, even if the liquid to be processed has a heat variability, the gas component and the liquid component can be separated without affecting the characteristics of the liquid to be processed. It can be separated and collected.

Further, since it is not necessary to use a power unit for degassing the dissolved gas, energy for operating such a power unit is not required, and no noise and vibration are generated by the power unit. In addition, there are many advantages such as a continuous gas-liquid separation operation due to space saving.

[Brief description of the drawings]

FIG. 1 is an overall view showing a schematic configuration of a gas-liquid separation device according to the present invention.

FIG. 2 is a cross-sectional view showing a degassing unit and a gas-liquid separation and recovery unit of the gas-liquid separation device shown in FIG. 1 in detail.

FIG. 3 is a view schematically showing a cross section of a porous tube constituting the gas-liquid separation and recovery section shown in FIGS. 1 and 2.

[Explanation of symbols]

 13 Stainless steel tube 14 PTC heating element 15 Porous tube 19 Pores D Gas-liquid separator V Degassing unit S Gas-liquid separation and collection unit

Continued on the front page (56) References JP-A-5-57108 (JP, A) JP-A-5-96103 (JP, A) JP-A-4-9602 (JP, U) (58) Fields surveyed (Int) .Cl. ⁷ , DB name) B01D 19/00

Claims (4)

(57) [Claims] 1. Dissolved gas contained in a liquid to be treated is physically separated (degassed) in a supply path of the liquid to be treated which is supplied to a space partitioned by a porous wall through which a liquid can pass. It is provided with a dissolved gas separation (degassing) means, and the separated liquid from which the dissolved gas has been separated (degassed) and removed by the dissolved gas separation (degassing) means is extracted outside the system from the porous wall. And said
In the space, the pressure of the liquid to be treated is applied to the bubble of the porous wall.
Pressure regulating valve to lower the pressure
Gas-liquid separator apparatus characterized by being. 2. The pressure regulating valve is fed into the space.
A vent valve is formed above the surface of the liquid to be treated.
The gas-liquid separation device according to claim 1, wherein: Wherein the dissolved gas separation (degassed) have been gas-liquid separator according to claim 1 or 2, characterized in that a heating means as the means. Wherein said dissolved gas separated gas-liquid separator according to claim 1 or 2, further comprising a vibration generating means as a (degassed) means.