Cleaning agent, cleaning method of water treatment apparatus, and cleaning method of silica-based scale

Patent metadata

Field	Value
Publication number	US-12371638-B2
Application number	US-202217683374-A
Country	US
Kind code	B2
Filing date	Mar 1, 2022
Priority date	Mar 1, 2022
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

The disclosure provides a silica-based scale cleaning technology. The disclosure can provide a cleaning agent of a silica-based scale, containing a silicic acid compound. The disclosure can also provide a cleaning method of a water treatment apparatus, including: using a solution containing a silicic acid compound. Further, the disclosure can provide a cleaning method of a silica-based scale, including: using an agent containing a silicic acid compound for a water system.

First claim

What is claimed is:

1. A cleaning method of a water treatment apparatus for removing a silica-based scale in a water system, comprising:
using a solution containing a silica-based scale cleaning agent that contains a silicic acid compound, or
using a solution containing a silicic acid compound,
wherein the solution is adjusted to have a pH of 10 or more, and
the solution contains the silicic acid compound in an amount of 1,000 to 20,000 mg/L in terms of the total silica content, or the solution is added to water to be treated in the water treatment apparatus to adjust the water to be treated to have a concentration of 1,000 to 20,000 mg/L in terms of the total silica content, and
the solution is adjusted to have a temperature of 50° C. or lower.

2. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the solution further contains a solid agent containing percarbonate.

3. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the solution further contains one or more selected from a chelating agent, a surfactant, and a dispersant.

4. A cleaning method of a silica-based scale, comprising:
using an agent containing a silicic acid compound in a water system, and the agent containing the silicic acid compound is a solution,
wherein the water system is adjusted to have a pH of 10 or more, and
the agent contains the silicic acid compound in an amount of 1,000 to 20,000 mg/L in terms of the total silica content, or the agent is added to water to be treated in the water system to adjust the water to be treated to have a concentration of 1,000 to 20,000 mg/L in terms of the total silica content, and
the solution is adjusted to have a temperature of 50° C. or lower.

5. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the cleaning agent contains the silicic acid compound in an amount of 3,000 to 10,000 mg/L in terms of the total silica content, or
the cleaning agent is used in a water system to obtain a concentration of 3,000 to 10,000 mg/L in terms of the total silica content.

6. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the water treatment apparatus is a water treatment apparatus provided with a membrane treatment apparatus.

7. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the silicic acid compound is metasilicic acid or a salt.

8. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 2 , wherein
the silicic acid compound is metasilicic acid or a salt.

9. The cleaning method of a water treatment apparatus for removing the silica-based scale in the water system according to claim 1 , wherein
the solution contains a chelating agent having a concentration of 0 to 10,000 mg/L.

10. The cleaning method of a silica-based scale according to claim 4 , wherein
the water system contains a chelating agent having a concentration of 0 to 10,000 mg/L.

Assignees

• Kurita Water Ind Ltd

Inventors

• MUELLER Jack
• JAFFARIAN Sara

Classifications

• C11D3/3902

  combined with specific additives · CPC title

• C11D7/14

  Silicates · CPC title

• C11D2111/20

  Industrial or commercial equipment, e.g. reactors, tubes or engines · CPC title

• C11D3/3942

  Inorganic per-compounds (C11D3/3902 takes precedence) · CPC title

• C11D3/33

  Amino carboxylic acids · CPC title