Abatement device

Patent metadata

Field	Value
Publication number	US-10618004-B2
Application number	US-201515523787-A
Country	US
Kind code	B2
Filing date	Nov 5, 2015
Priority date	Nov 14, 2014
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

Provided is an abatement device that reduces an amount of drainage of circulating water. The abatement device lowers an average drainage flow of circulating water to a low flow, when a ratio of a concentration of silicon dioxide within the circulating water and a concentration of hydrogen fluoride within the circulating water is greater than or equal to a predetermined value at which hydrofluorosilicic acid can be produced, and raises the average drainage flow of the circulating water to a high flow higher than the low flow, when the ratio of the concentration of silicon dioxide within the circulating water and the concentration of hydrogen fluoride within the circulating water is less than the predetermined value.

First claim

What is claimed is:

1. An abatement device that processes exhaust gas containing silicon and exhaust gas containing fluorine, the abatement device comprising:
a drain tank for holding circulating water that dissolves silicon dioxide produced from the exhaust gas containing the silicon and hydrogen fluoride produced from the exhaust gas containing the fluorine;
a circulation path communicating with the drain tank;
a drain valve provided to the circulation path to drain a part of the circulating water outside;
a makeup water supply means for supplying makeup water to the circulation path; and
a control means for controlling the drain valve and the makeup water supply means to control an average drainage flow of the circulating water within the circulation path, for lowering the average drainage flow of the circulating water to a low flow, in response to determining a ratio of a concentration of the silicon dioxide within the circulating water and a concentration of the hydrogen fluoride within the circulating water is greater than or equal to a predetermined value at which hydrofluorosilicic acid can be produced, and for raising the average drainage flow of the circulating water to a high flow higher than the low flow, in response to determining the ratio of the concentration of the silicon dioxide within the circulating water and the concentration of the hydrogen fluoride within the circulating water is less than the predetermined value.

2. The abatement device according to claim 1 , wherein the control means determines the concentration of the silicon dioxide on the basis of an integrated amount of flow of the exhaust gas containing the silicon, the average drainage flow of the circulating water, and a flow of the makeup water.

3. The abatement device according to claim 1 , wherein the control means determines the concentration of the hydrogen fluoride on the basis of an integrated amount of flow of the exhaust gas containing the fluorine, the average drainage flow of the circulating water, and a flow of the makeup water.

4. The abatement device according to claim 1 , further comprising an acidity measuring means for measuring an acidity of the circulating water.

5. The abatement device according to claim 4 , wherein the acidity is determined on the basis of a concentration of the hydrogen fluoride within the circulating water measured by a conductivity sensor.

6. The abatement device according to claim 1 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

7. The abatement device according to claim 2 , wherein the control means determines the concentration of the hydrogen fluoride on the basis of an integrated amount of flow of the exhaust gas containing the fluorine, the average drainage flow of the circulating water, and a flow of the makeup water.

8. The abatement device according to claim 2 , further comprising an acidity measuring means for measuring an acidity of the circulating water.

9. The abatement device according to claim 3 , further comprising an acidity measuring means for measuring an acidity of the circulating water.

10. The abatement device according to claim 7 , further comprising an acidity measuring means for measuring an acidity of the circulating water.

11. The abatement device according to claim 8 , wherein the acidity is determined on the basis of a concentration of the hydrogen fluoride within the circulating water measured by a conductivity sensor.

12. The abatement device according to claim 9 , wherein the acidity is determined on the basis of a concentration of the hydrogen fluoride within the circulating water measured by a conductivity sensor.

13. The abatement device according to claim 2 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

14. The abatement device according to claim 3 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

15. The abatement device according to claim 4 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

16. The abatement device according to claim 7 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

17. The abatement device according to claim 8 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

18. The abatement device according to claim 9 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

19. The abatement device according to claim 5 , further comprising a centrifugal separator that separates the silicon dioxide from the circulating water.

Assignees

• Edwards Japan Ltd

Inventors

• Yamada Toshiki
• Pope Alexander Michael
• Bennett Alistair
• Barlow Steven
• Jones Christopher Peter

Classifications

• H10P14/60

  of insulating materials · CPC title

• B01D53/346

  Controlling the process · CPC title

• C23C16/52

  Controlling or regulating the coating process {(C23C16/45557, C23C16/279 take precedence)} · CPC title

• C23C16/4412

  Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps · CPC title

• B01D21/267

  by using a cyclone · CPC title