Method and apparatus for supplying water of specified concentration

Patent metadata

Field	Value
Publication number	US-11565224-B2
Application number	US-201716497957-A
Country	US
Kind code	B2
Filing date	Sep 15, 2017
Priority date	Mar 30, 2017
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

Provided are a method for supplying water of specified concentration, including: a step of adding at least two liquids, a conductive first liquid and a non-conductive second liquid, to ultrapure water to produce water of specified concentration containing a first liquid-component and a second liquid-component at specified concentrations, in which a mixed solution in which the first liquid and the second liquid are mixed at a specified mixing ratio in advance is prepared; and the mixed solution is added to the ultrapure water so that a conductivity or specific resistance of the ultrapure water after the addition satisfies a specified value, and an apparatus therefor.

First claim

The invention claimed is:

1. A method for supplying water of specified concentration, comprising:
supplying a conductive first liquid-component to a reservoir while measuring an amount thereof;
supplying a non-conductive second liquid-component to the reservoir while measuring an amount thereof, to thereby produce in the reservoir a mixed solution with a specified concentration containing the first liquid-component and the second liquid-component;
adding the mixed solution in the reservoir to ultrapure water flowing through a line;
measuring a conductivity or specific resistance of the ultrapure water in the line into which the mixed solution has been added;
measuring an instantaneous flow rate of the ultrapure water in the line into which the mixed solution has been added; and
controlling an amount of the mixed solution in the reservoir added to the line so that a value of the conductivity or the specific resistance is a specified value.

2. The method for supplying water of specified concentration according to claim 1 , wherein
the first liquid is an aqueous solution of an acid or alkali, and
the second liquid is H 2 , H 2 O 2 , or O 3 -dissolved water.

3. An apparatus for supplying water of specified concentration, comprising:
a reservoir;
a conductive first liquid line providing a predetermined amount of a conductive first liquid to the reservoir;
a conductive second liquid line providing a predetermined amount of a non-conductive second liquid to the reservoir, to thereby prepare in the reservoir a mixed solution of the conductive first liquid and the non-conductive second liquid at a specified mixing ratio;
a mixed solution feeder configured to supply the mixed solution in the reservoir into ultrapure water;
a conductivity meter or a resistivity meter configured to measure a conductivity or specific resistance of the ultrapure water into which the mixed solution has been supplied;
an instantaneous flow meter configured to measure an instantaneous flow rate of the ultrapure water into which the mixed solution has been supplied; and
a controller configured to control the mixed solution feeder so that a value detected by the conductivity meter or the resistivity meter is a specified value.

4. The apparatus for supplying water of specified concentration according to claim 3 , wherein
the first liquid is an aqueous solution of an acid or alkali, and
the second liquid is H 2 , H 2 O 2 , or O 3 -dissolved water.

Assignees

• Kurita Water Ind Ltd

Inventors

• Iino Hideaki

Classifications

• B01F33/80

  Mixing plants; Combinations of mixers · CPC title

• B01F35/80 Primary

  Forming a predetermined ratio of the substances to be mixed (controlling ratio of two or more flows of fluid or fluent material G05D11/02) · CPC title

• B01F33/834

  Mixing in several steps, e.g. successive steps (B01F33/81, B01F33/82 and B01F33/85 take precedence) · CPC title

• B01F23/483

  using water for diluting a liquid ingredient, obtaining a predetermined concentration or making an aqueous solution of a concentrate · CPC title

• B01F35/2132 Primary

  Concentration, pH, pOH, p(ION) or oxygen-demand (B01F35/2133 takes precedence) · CPC title