JPS6244964B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an apparatus for producing a high-purity solution of a water-soluble gas, which is used to produce a solution of high-purity chemicals, reagents, etc. that can be used, for example, in the production of semiconductors. BACKGROUND ART Conventionally, when producing high-purity ammonia water used in semiconductor manufacturing technology, for example, a method of blowing ammonia gas into ultrapure water has been used. However, with this method, there is a problem that impurities and particulates in the gas get mixed into the solution, and with the method of blowing the raw material gas into ultrapure water, it is difficult to easily and accurately adjust the concentration. Ta. Problems to be Solved by the Invention Therefore, in the present invention, instead of blowing the raw material gas into ultrapure water, the raw water is dissolved in the raw water through a hydrophobic porous membrane, thereby eliminating impurities and fine particles in the gas. The aim is to solve the problem of contamination and easy and accurate adjustment of the concentration of the solution to be produced. Means for Solving the Problems In order to achieve the above-mentioned object, the device according to the invention comprises a hydrophobic porous membrane in a container with an inlet for raw water for making the required solution and an outlet for the solution. When dissolving the raw water-soluble gas in the raw water through this hydrophobic porous membrane, the pressure of the raw water is
The pressure is set to be equal to or higher than the pressure of the water-soluble gas supplied as a raw material, and at a value that does not allow raw water to leak through the hydrophobic porous membrane to the water-soluble gas supplied as a raw material. There is. The raw material gas may be any gas that dissolves in water; examples include inorganic substances such as hydrogen chloride and hydrogen fluoride, organic acids such as formic acid and acetic acid, organic solvents such as alcohol, chlorine gas, and amines. Can be done. Function In the device of the present invention configured as described above,
The raw material gas is dissolved in the raw water through the hydrophobic porous membrane, so even if there are impurity gases or fine particles in the raw water, they will not be mixed into the raw water. Further, the solution concentration can be easily changed arbitrarily by adjusting the supply flow rate of the raw material gas. Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings. The drawing schematically shows the configuration of an apparatus according to an embodiment of the present invention, in which 1 is a container equipped with an inlet 1a for raw water (for example, ultrapure water) and an outlet 1b for the produced solution; A hollow hydrophobic porous membrane 2 is disposed approximately on the central axis along its longitudinal direction, and a raw material gas inlet 3 and an impurity outlet 4 are attached to one end and the other end, respectively. The raw material gas inlet 3 is connected to a raw material gas supply source (not shown) via a suitable flow rate regulating means (not shown). The hollow hydrophobic porous membrane 2 is preferably, for example, a hollow fiber membrane member (for example,
Hollow fiber membranes made of polyolefin are commercially available from Mitsubishi Rayon Co., Ltd. (hollow fibers with an outer diameter of about 0.1 to 0.5 mm and a wall thickness of about 0.01 to 0.2 mm) are used. In the operation of the device configured in this way, to explain the case of producing high-purity ammonia water using ultrapure water and ammonia gas, the ammonia gas is reduced to an appropriate pressure from a gas cylinder, and then the flow rate is adjusted using a flow rate adjustment valve, etc. It is fed into the hydrophobic porous membrane 2 through the inlet section 3 in a conditioned state. On the other hand, since the pressure of the ultrapure water supplied from the inlet 1a of the container 1 is equal to or higher than the pressure of the ammonia gas, the supplied ammonia gas substantially passes through the passage in the membrane 2 and reaches the outlet. Flows towards 4. At this time, ammonia gas is dissolved in the ultrapure water that permeates through the membrane 2 and enters inside. Note that when the pressure of the water-soluble gas supplied as a raw material becomes higher than the pressure of the raw water, the water-soluble gas does not dissolve into the raw water but enters the raw water in the form of bubbles. On the other hand, as mentioned above, the upper limit of the pressure of raw water is until the raw water does not leak through the hydrophobic porous membrane to the water-soluble gas side that is supplied as a raw material.
~10Kg/ ^cm2 . In this case, by appropriately selecting the flow rate of ammonia gas and the area of the permeable membrane 2, almost all of the ammonia is dissolved in water, and only a small amount comes out from the impurity outlet 4. The table below shows examples of ammonia gas and ultrapure water flow rates and ammonia water concentrations.

[Table] The illustrated embodiments are merely for illustration purposes, and the shape and configuration of the container to which ultrapure water is supplied and the permeable membrane inserted therein may be modified or changed as necessary. can do. Effects As explained above, according to the present invention, the raw material gas is dissolved in the raw water through the hydrophobic porous membrane without blowing the raw material gas into the raw water. Even if the water contains impurities or fine particles, they will not mix into the solution, and even if impurity gases are contained, they will not dissolve in the water and will not remain as bubbles. Aqueous solutions can be obtained. Further, by adjusting the flow rate of the raw material gas, a solution with a desired concentration can be easily prepared.

[Brief explanation of the drawing]

The drawing is a partial sectional view showing an embodiment of the present invention. In the figure, 1: container, 1a: raw water inlet, 1b: solution outlet, 2: hydrophobic porous membrane.

Claims (1)

[Claims] 1. A hydrophobic porous membrane is provided in a container equipped with an inlet for raw water and an outlet for the solution to produce the required solution,
When dissolving a water-soluble gas as a raw material into raw water through this hydrophobic porous membrane, the pressure of the raw water is equal to or higher than the pressure of the water-soluble gas supplied as a raw material, and the raw water is hydrophobic and porous. 1. An apparatus for producing a high-purity solution of a water-soluble gas, characterized in that the value is set to a value that does not leak to the water-soluble gas side supplied as a raw material through a membrane.