JPH07185211A - Method and apparatus for member type aeration - Google Patents

Abstract

PURPOSE:To effect a specified aeration performance from the initial stage of operating apparatus by supplying an aeration gas from the gas phase side of a gas permeable membrane and filling at least the gas phase side with the gas before liquid to be treated is passed on the liquid phase side of the membrane. CONSTITUTION:An aeration gas is supplied continuously on the gas phase side 10b of a gas permeable membrane 11 before liquid to be treated is passed on the liquid phase side 10a of the membrane 11. With the gas phase side 10b at least filled with the gas, a valve mechanism 16 is shifted to a closed state, and then liquid to be treated is introduced on the liquid phase side of a membrane module 10 from an introduction line 12. From the difference in the partial pressure ratios of the gas between the liquid phase 10a of the module 10 and the gas phase 10b, a gas to be removed in the liquid to the treated moves from the liquid phase side 10a to the gas phase side 10b through the gas permeable membrane 11, while the aeration gas moves to the liquid phase side 10a, so that the gas to be removed is eliminated from the liquid to be treated. In this way, a gas other than the aeration gas is prevented from transferring to the liquid to be treated through the gas permeable membrane in the initial stage of the aeration treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid product such as a liquid drink including an alcoholic drink, a pharmaceutical product, a cosmetic product, etc., which needs deoxidation treatment or other dissolved gas removal in order to maintain quality, and a cleaning water. Improvement of membrane type aeration method and equipment for obtaining water that needs deoxidation treatment and other dissolved gas removal to prevent corrosion of work and piping such as water in pipes of buildings and buildings It is a thing.

[0002]

2. Description of the Related Art As is well known, dissolved oxygen in a liquid is considered to be a factor of oxidation, and when the liquid itself is a product,
It causes the deterioration of the components in the liquid and oxidizes the object to be cleaned when it is used for cleaning or the like. For example, in alcoholic beverages such as sake, wine, shochu, soft drinks, fruit juice drinks, etc., deterioration of flavor due to the influence of oxygen dissolved in the drink,
Discoloration occurs.

In order to prevent such a phenomenon, the dissolved gas containing dissolved oxygen may be removed from the liquid product, and such dissolved gas can be removed by a vacuum degassing method, an aeration method (gas replacement method), It is performed by a thermal deaeration method, a chemical deaeration method, or the like. However, among the above-mentioned degassing methods, the heating degassing method heats the liquid to be treated in an open system and releases and dissolves the dissolved gas.Therefore, oxygen is generated due to careless operation and malfunction of the equipment. It may be redissolved and cannot be applied to substances that are altered by heat. In the chemical deaeration method, since a chemical such as an oxygen scavenger is used, the flavor of the product is impaired and there is a problem in safety. Therefore, the vacuum deaeration method and the aeration method are adopted in the liquid products such as the above liquid drinks and pharmaceuticals.

Further, depending on the liquid product, it is necessary to remove only the dissolved oxygen and not the other specific gas (for example, carbon dioxide gas) to make it dissolved. For example, in the case of liquid products such as beer, sparkling wine, sparkling liquor and carbonated drinks that require dissolved carbon dioxide gas, the vacuum degassing method not only dissolves oxygen but also an important factor of flavor. The carbon dioxide gas is removed. In this case, it becomes necessary to re-add carbon dioxide gas later, and the cost at this time becomes very high, so in this type of liquid product,
Deoxidation is performed by an aeration method using carbon dioxide.

Dissolved oxygen is removed by the conventional aeration method (gas replacement method) described above by blowing a high-purity gas other than oxygen (for example, nitrogen gas, carbon dioxide gas) into the liquid to be treated in the aeration tank. The dissolved oxygen is physically removed by directly contacting the gas with the liquid to be treated and lowering the oxygen partial pressure in the liquid.

[0006] By the way, since the method using such an aeration tank is performed in a batch system, a large amount of gas for aeration is required, and a large amount of bubbles are generated by the aeration, so that the effective volume of the tank is increased. Because of the small size, a large-scale aeration tank is required. Therefore, in recent years, such an aeration method has been improved, and a so-called membrane aeration method using a gas permeable membrane and an apparatus to which this is applied are widely used.
That is, this membrane gas replacement method uses a gas permeable membrane that allows only gas to pass through without passing through liquid, and a gas other than the gas to be removed is blown into the liquid to be treated through this membrane and directly to the liquid to be treated. The target dissolved gas is removed by bringing them into contact with each other and lowering the partial pressure of the gas to be removed in the liquid.

[0007]

By the way, when the dissolved oxygen is removed by aeration using the aeration apparatus as described above, there is a feature that deoxidation treatment can be continuously performed. There is a problem that the dissolved oxygen concentration of the aeration treatment liquid at that time is not sufficiently lowered. The treatment liquid in which the dissolved oxygen has not decreased at such a stage is either discarded as it is, or is recirculated to the upstream side of the aeration apparatus and circulated again, and the dissolved oxygen concentration of the treatment liquid is set to a predetermined value. At that point, it is sent to the subsequent apparatus or process as a deoxidized treatment liquid.

For example, when the stock solution for treatment is an important problem such as the above-mentioned beer due to the oxidation by dissolved oxygen, the dissolved oxygen in the treated solution is not sufficiently removed at the initial stage of the degassing process. The treatment liquid is not sent to the subsequent process but is temporarily stored in a tank or the like, and the treatment liquid is sent to the subsequent process when the dissolved oxygen is reduced to a predetermined value. Further, the above-described deoxidized insufficient treatment liquid in the storage tank is subjected to aeration treatment again and then sent to the subsequent step.

That is, it is difficult to maintain a constant dissolved oxygen removal performance from the initial stage of operation in the above-described membrane-type aerator capable of continuous treatment. Therefore, the present invention has the problem of the above-mentioned membrane-type deaerator. It is an object of the present invention to solve the above problems and provide a membrane-type aeration method capable of maintaining a predetermined aeration performance from the initial operation of the apparatus and an apparatus thereof.

[0010]

The present invention has been made in view of the above problems. Specifically, one or more kinds of gases are dissolved in the liquid phase side on one side of the gas permeable membrane. The liquid to be treated is circulated, the aeration gas of a type other than the dissolved gas to be removed is circulated to the gas phase side on the other side, and gas permeation is caused by the partial pressure difference between the dissolved gas to be removed and the aeration gas in the liquid to be treated. Performing gas replacement through the membrane, a membrane-type aeration method for separating the dissolved gas to be removed from the liquid to be treated through the gas permeable membrane, prior to circulating the liquid to be treated on the liquid phase side,
A membrane-type aeration method characterized by supplying an aeration gas to the gas phase side and filling at least the gas phase side of the liquid phase side and the gas phase side. A liquid to be treated in which one or more kinds of gases are dissolved is circulated on the phase side, and an aeration gas of a type other than the dissolved gas to be removed is circulated on the other side of the gas phase to be removed in the liquid to be treated. A membrane-type aerator for performing gas replacement through a gas permeable membrane by a partial pressure difference between a dissolved gas and an aeration gas, and separating a dissolved gas to be removed from a liquid to be treated through the gas permeable membrane, wherein the liquid phase A supply line for supplying an aeration gas to the gas phase side prior to supplying the liquid to be processed to the liquid phase side from the introduction line by connecting the introduction line and the derivation line of the treatment liquid to the side It is a membrane-type aerator characterized by connecting the.

[0011]

According to the present invention, one side (liquid phase side) of the gas permeable membrane is used when performing the membrane aeration process using the gas permeable membrane.
Before the liquid to be treated is circulated, the gas for aeration is supplied from the gas phase side and at least the gas phase is filled so that the gas other than the gas for aeration does not form a gas permeable film at the beginning of the aeration process. To prevent it from moving toward the liquid to be treated.

[0012]

EXAMPLES Examples of the method of the present invention will be described below. First, a liquid (hereinafter, referred to as a liquid to be processed) which is subjected to the film-type aeration process does not deteriorate or deteriorate the liquid even if dissolved in the liquid (hereinafter, referred to as an aeration gas). ) And a gas that needs to be removed from the liquid to be treated (hereinafter referred to as a removal target gas). The gas for aeration at this time may be one type of gas used alone or a mixture of a plurality of types of gas at an appropriate ratio,
Further, the gas to be removed may be one kind of gas or plural kinds of gas. Of course, the gas to be removed and the gas to be aerated are of different types.

Then, the aeration gas is first supplied to one side of the gas permeable membrane (hereinafter, this side is referred to as a gas phase side). Then, the gas for aeration pushes the air remaining on the gas phase side toward the other side of the gas permeable membrane (hereinafter, this side is referred to as the liquid phase side), and at the same time, the air together with the air causes the liquid phase side. Move to. Further, the aeration gas that has moved to the liquid phase side pushes out the air remaining on the liquid phase side toward the introduction part of the liquid to be treated and the discharge part of the aeration treatment liquid in the same manner as described above. Therefore, the gas for aeration fills not only the gas phase side partitioned by the gas permeable membrane, but also the liquid phase side and the entire space continuous to this liquid phase side.

Next, in this state, that is, in the state where the aeration gas is continuously supplied to the gas phase side, the liquid to be treated is introduced into the liquid phase side. Then, the liquid phase side and the gas phase side sandwiching the gas permeable membrane move between the gas phase side and the liquid phase side so that the ratios of the partial pressures of the gas for aeration and the gas to be removed become equal. At this time, since the gas for aeration is continuously supplied to the gas phase side, the partial pressure of the gas to be removed is 0 in the initial stage. Therefore, the gas to be removed is from the liquid phase side to the gas phase side,
Since the aeration gas moves from the gas phase side to the liquid phase side through the gas permeable membrane, the partial pressure of the aeration gas on the liquid phase side increases,
The partial pressure of the gas to be removed is reduced, and as a result, the gas to be removed is removed from the liquid to be treated. At this time, by supplying only the gas for aeration to the gas phase side and keeping the partial pressure of the gas to be removed on the gas phase side as low as possible, the gas to be removed on the liquid phase side becomes substantially zero. Can be removed up to.

In the above description, since the partial pressure difference is utilized during aeration as described above, it is desirable that the gas to be supplied to the gas phase side is supplied in a pressurized state. While more effectively removing the dissolved gas,
It is possible to effectively prevent a decrease in the dissolved amount of gas that does not need to be removed.

Next, an example of an apparatus to which the method of the present invention is applied will be described with reference to FIG. In the drawing, the membrane module (10) is internally divided into a gas phase side and a liquid phase side by a gas permeable membrane such as a hollow fiber shape, a spiral shape (glue shape), a pleat shape, or a flat membrane shape. The gas permeable membrane (11) divides the internal space of the membrane module (10) into a liquid phase side (10a) through which the liquid to be treated flows and a gas phase side (10b) at which the aeration gas is supplied. In the membrane module (10) of this type of configuration, generally, a so-called cross-flow method of circulating the liquid to be treated in parallel with the membrane surface of the gas permeable membrane is adopted, thereby suppressing clogging of the membrane surface. In this way, stable membrane performance is maintained and the membrane life is extended.

An inlet line (12) for the liquid to be treated is connected to one end of the liquid phase side (10a) of the membrane module (10), and an outlet line (13) for the treatment liquid is connected to the other end. An aeration gas supply line (hereinafter referred to as an aeration line) (14) is connected to one end of the phase side (10b), and an exhaust line (15) is connected to the other end. Then, in the middle of the exhaust line (15), the on-off valve mechanism (1
6) is connected.

The above-mentioned processing liquid outlet line (13) is connected to, for example, a subsequent apparatus or process. An aeration gas supply mechanism (not shown) is connected to the upstream side of the aeration line (14), and the aeration gas supply mechanism is
In addition to a cylinder or the like containing the gas, a known chemical or physical gas generating means or the like can be used. Also,
The arrangement direction of the membrane module (10) and the flowing direction of the liquid to be treated in the membrane module (10) are such that the liquid to be treated flows in the membrane module (10) from the lower side to the upper side or in the lateral direction. It is preferable to install the membrane module (10) so as to flow, and it is most preferable to install the liquid to be treated so as to flow in the membrane module (10) from the lower side to the upper side. When the liquid to be treated is made to flow downward from above,
The aeration gas blown into the liquid to be treated by aeration accumulates on the inflow side (upper side) in the liquid flow direction, obstructing the flow of the liquid, resulting in insufficient aeration and the desired concentration of the gas to be removed. The disadvantage is that the stabilization time until it becomes longer becomes longer.

In the above structure, first, the exhaust line (1
5) Leave the open / close valve mechanism (16) in the open state, and in this state, from the aeration line (14) to the gas phase side (1) of the membrane module (10).
Supply gas for aeration to 0b). Then, the aeration gas is
The air remaining on the gas phase side (10b) is pushed out of the system through the exhaust line (15) and, at the same time, it passes through the gas permeable membrane (11) and the liquid phase side (1
It is extruded toward 0a) and moves to the liquid phase side (10a) together with this air. Furthermore, the aeration gas that has moved to the liquid phase side (10a) is
Similarly to the above, the air remaining on the liquid phase side (10a) is extruded toward the above-mentioned introduction line (12) and discharge line (13). Therefore, the aeration gas is on the gas phase side divided by the gas permeable membrane (11).
Not only (10b), but also the liquid side (10a) and this liquid side (10a)
The air in the entire space linked to is eliminated and filled.

Next, in this state, that is, in the state where the aeration gas is continuously supplied to the gas phase side (10b), the on-off valve mechanism (16) is switched to the closed state, and then the introduction line The liquid to be treated is introduced from (12) into the liquid phase side (10a) of the membrane module (10). Then, as described above, due to the difference in the partial pressure ratio of the gas on the liquid phase side (10a) and the gas phase side (10b) in the membrane module (10), the gas to be removed in the liquid to be treated is the liquid phase side. (10a) moves to the gas phase side (10b) through the gas permeable membrane (11), while the aeration gas moves to the liquid phase side (10a), resulting in removal of the gas to be removed from the liquid to be treated. To be done. At this time, on the gas phase side (10b)
Since the gas for aeration is continuously supplied to, the partial pressure of the gas to be removed is 0 in the initial stage. Therefore, the gas to be removed moves from the liquid phase side to the gas phase side, and the aeration gas moves from the gas phase side to the liquid phase side through the gas permeable membrane, so the partial pressure of the aeration gas on the liquid phase side increases. However, the partial pressure of the gas to be removed is reduced, and as a result, the gas to be removed is removed from the liquid to be processed.

At the beginning of this aeration process, the gas phase side (1
0b), as well as the liquid phase side (10a) and almost all the space connected to this liquid phase side (10a) is substantially filled with aeration gas, so the liquid to be treated does not come into contact with air. From the time of introduction, it is aerated by the gas for aeration through the gas permeable membrane. Therefore, the removal target gas remaining in the treatment liquid has a substantially desired removal concentration from the initial point in time, and the time for stabilizing the removal concentration, which conventionally takes a long time, is almost unnecessary.

FIG. 2 shows an example of measurement of changes in the dissolved oxygen concentration of the treatment liquid when aeration treatment is performed by the method of the present invention and the conventional method. In this example, general tap water was used as the liquid to be treated, and nitrogen gas was used as the gas for aeration, and the tap water had a dissolved oxygen concentration of 8.5 ppm and a liquid temperature of 20 ppm.
℃ supplied at a supply pressure 2.0 kg / m ² things, nitrogen gas (purity
99.9%) was supplied at a supply pressure of 1.5 kg / m ² and aerated. As can be seen from this figure, in the case of the method of the present invention, the dissolved oxygen concentration in the treatment liquid starts to decrease rapidly immediately after the start of the supply of the treatment liquid as compared with the conventional method. The time required for the concentration to stabilize is 30 minutes or more in the case of the conventional method, while it is about 5 minutes in the case of the method and apparatus of the present invention, which is greatly reduced to about 1/6 or less. ing.

Specific application fields of the membrane-type aeration method and apparatus according to the present invention are as follows. That is, the production line of products such as liquid drinks, pharmaceuticals, cosmetics, etc., for which deoxidation treatment is suitable for maintaining quality, cleaning water from which dissolved oxygen is removed in order to prevent oxidation and corrosion of the work. This is the case where the deoxidizing process is performed on the water in the pipes, hot water, etc. to prevent the generation of red water by corroding the hot water supply / water supply pipes of the building, the cleaning process of electronic parts and precision parts that require.

Particularly, in such an application, it is suitable for preventing re-dissolution of dissolved oxygen and other kinds of gas. That is, the treatment liquid is saturated by the aeration gas being dissolved by the aeration, and the redissolution of oxygen and other types of gas can be effectively prevented.

In the above description, the gas to be removed has been described as dissolved oxygen in the liquid to be treated, but in the present invention, the gas to be removed is not limited to oxygen.

The aeration gas can also be appropriately changed depending on the properties and composition of the liquid to be treated. In the above-mentioned use, the aeration gas may be an inert gas such as nitrogen, but the liquid to be treated is not limited. In some cases, it is preferable that plural kinds of gases are dissolved therein, and some of the gases are dissolved, and in this case, aeration is performed using a gas that needs to be dissolved. For example, when the liquid to be treated is a substance containing carbon dioxide gas such as beer or carbonated drink, dissolved oxygen is removed by using carbon dioxide gas as an aeration gas.

In addition to the above-mentioned application examples, other effervescent wines, alcoholic beverages such as shochu, other beverages, liquid seasonings such as soy sauce, liquid products such as cosmetic liquids, and raw material liquids thereof It can be easily applied even in the production line for concentrated stock solutions, split water, etc.

[0028]

According to the present invention, when performing a membrane-type aeration process using a gas permeable membrane, the gas for aeration is used prior to flowing the liquid to be treated to one side (liquid phase side) of the gas permeable membrane. By supplying gas from the gas phase side and filling at least the gas phase side, it is possible to prevent gases other than the gas for aeration from moving toward the liquid to be processed through the gas permeable membrane at the beginning of the aeration process. Therefore, the concentration of the gas to be removed is sufficiently lowered at the beginning of the aeration process to reach the desired removal concentration, and the time required for stabilization of the removal concentration, which conventionally took a long time, is almost unnecessary. Becomes Further, it is possible to improve the yield by discarding wastefully as a defective aeration process, or by drastically reducing the amount of the processing liquid that has recirculated to the upstream side of the aeration device.

Therefore, according to the present invention, it is possible to provide a membrane-type aeration method and an apparatus therefor capable of maintaining a predetermined aeration performance from the initial stage of the aeration treatment, thereby improving the treatment performance and the yield. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a membrane type aeration apparatus according to the present invention.

FIG. 2 is a graph showing changes in the dissolved oxygen concentration of the treatment liquid when aeration is performed by the method of the present invention and the conventional method.

[Explanation of symbols]

 (10) Membrane module (10a) Liquid phase side (10b) Gas phase side (11) Gas permeable membrane (12) Treatment liquid introduction line (13) Treatment liquid discharge line (14) Aeration gas supply line ( Aeration line) (15) Exhaust line (16) Open / close valve mechanism

Claims (2)

[Claims] 1. A liquid-phase side of one side of a gas-permeable membrane,
A liquid to be treated in which one or more kinds of gases are dissolved is circulated,
A gas for aeration other than the dissolved gas to be removed is circulated with the other side as the gas phase side, and gas replacement is performed through the gas permeable membrane due to the partial pressure difference between the dissolved gas to be removed and the aeration gas in the liquid to be treated. A membrane-type aeration method for separating a dissolved gas to be removed from a liquid to be treated through a gas permeable membrane, wherein the gas for aeration is vaporized on the gas phase side before the liquid to be treated is circulated to the liquid phase side. Is supplied to at least the gas phase side of the liquid phase side and the gas phase side to fill the gas phase side. 2. One side of the gas permeable membrane (10) is connected to a liquid phase side (10
As a), the liquid to be treated in which one or more kinds of gases are dissolved is circulated, and the aeration gas of a type other than the dissolved gas to be removed is circulated with the other side as the gas phase side (10b), Membrane that performs gas replacement through the gas permeable membrane (11) by the partial pressure difference between the dissolved gas to be removed and the aeration gas, and separates the dissolved gas to be removed from the liquid to be treated through the gas permeable membrane (11). A type aerator, in which the liquid-introducing line (12) and the outlet line (13) are connected to the liquid-phase side (10a), and the liquid-phase side (10a) is processed from the introductory line (12). A membrane-type aerator characterized in that, prior to supplying a liquid, an aeration gas supply line (14) for supplying an aeration gas is connected to the gas phase side (10b).