Low risk chlorine dioxide onsite generation system

Patent metadata

Field	Value
Publication number	US-10501345-B2
Application number	US-201815928749-A
Country	US
Kind code	B2
Filing date	Mar 22, 2018
Priority date	Aug 17, 2017
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

The present disclosure generally relates to methods of treating process water using a reactor for generating chlorine dioxide onsite. The onsite generation system may include double ensured precursor feeding, effective reactor, automated control/alarm, and effective product delivery. The reactor may include a mixing device, a first feed line connected to the mixing device, and a second feed line connected to the mixing device. The reactor may include a proximal portion in fluid communication with the mixing device and a distal portion in fluid communication with a motive water line. The mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line may be positioned within the motive water line.

First claim

What is claimed is:

1. A method of treating process water, comprising:
feeding a first solution comprising an acid through a first feed line into a mixing device;
feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;
mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is connected to a reactor;
feeding the reaction mixture into the reactor;
reacting the acid, the chlorate, and the hydrogen peroxide to produce chlorine dioxide in the reactor, wherein the reactor comprises a proximal portion connected to the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degrees to about 60 degrees;
mixing the chlorine dioxide with motive water in the motive water line at the distal portion of the reactor; and
injecting the chlorine dioxide and the motive water into the process water.

2. The method of claim 1 , further comprising cooling the mixing device and the reactor with the motive water.

3. The method of claim 1 , wherein the acid is sulfuric acid.

4. The method of claim 1 , wherein the first feed line and the second feed line are opposite to and directed against each other.

5. The method of claim 1 , wherein the motive water line comprises at least two longitudinal channels through which motive water may flow.

6. The method of claim 5 , wherein the reaction mixture has a residence time in the reactor of at least about 0.1 minute, and a precursor velocity is at least about 25 cm/min, wherein the precursor velocity is a velocity of the first and second solutions.

7. The method of claim 6 , wherein the reactor is operated at a pressure about equal to or greater than atmospheric pressure.

8. The method of claim 1 , further comprising producing the chlorine dioxide at a rate ranging from about 0.001 lb/hour to about 20 lb/hour.

9. The method of claim 1 , further comprising operating the reactor at a temperature ranging from about 2° C. to about 80° C.

10. The method of claim 1 , further comprising determining a chlorine dioxide demand in the process water using measurements selected from a chlorine dioxide sensor, an oxidation and reduction potential, a flow meter, a microbiological measurement, and any combination thereof.

11. The method of claim 1 , wherein a cooling tower comprises the process water.

12. A method, comprising:
feeding a first solution comprising an acid through a first feed line into a mixing device;
feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;
mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is connected to a reactor;
feeding the reaction mixture into the reactor;
reacting the acid, the chlorate, and the hydrogen peroxide to produce chlorine dioxide in the reactor, wherein the reactor comprises a proximal portion connected to the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degrees to about 60 degrees;
mixing the chlorine dioxide with motive water in the motive water line at the distal portion of the reactor; and
injecting the chlorine dioxide into an aqueous system.

13. The method of claim 12 , wherein the reactor is in fluid communication with a product feed line.

14. The method of claim 12 , further comprising determining a flow rate of the first solution in the first feed line.

15. The method of claim 12 , further comprising determining a flow rate of the second solution in the second feed line.

16. The method of claim 12 , further comprising determining a flow rate of a chlorine dioxide solution in a product feed line.

17. The method of claim 12 , further comprising determining a flow rate of the motive water in the motive water line.

18. The method of claim 12 , further comprising sensing a reactor pressure.

19. A method of producing chlorine dioxide, comprising:
feeding a first solution comprising an acid through a first feed line into a mixing device;
feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;
mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is in fluid communication with a reactor;
feeding the reaction mixture into the reactor;
reacting the acid, the chlorate, and the hydrogen peroxide in the reactor, wherein the reactor comprises a proximal portion in fluid communication with the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degree to about 60 degrees; and
mixing chlorine dioxide with motive water in the motive water line at the distal portion of the reactor.

20. The method of claim 19 , wherein the acid is sulfuric acid.

21. The method of claim 19 , wherein the reactor is operated at a pressure about equal to or greater than atmospheric pressure.

22. The method of claim 19 , further comprising producing the chlorine dioxide at a rate ranging from about 0.001 lb/hour to about 20 lb/hour.

23. The method of claim 19 , further comprising operating the reactor at a temperature ranging from about 2° C. to about 80° C.

Assignees

• Ecolab Usa Inc

Inventors

• Xiong Kun
• Rader Emily
• Jefferson James L
• Dimascio Felice
• O'Brien Donald
• Denny Nicholas Ryan
• Tabor Gary
• Papanek David R

Classifications

• C02F1/686

  Devices for dosing liquid additives · CPC title

• C02F1/76

  with halogens or compounds of halogens {(C02F1/4674 takes precedence)} · CPC title

• C02F2303/04

  Disinfection · CPC title

• C02F1/006

  Water distributors either inside a treatment tank or directing the water to several treatment tanks; Water treatment plants incorporating these distributors, with or without chemical or biological tanks (for settling tanks B01D21/24) · CPC title

• C02F2209/005

  Processes using a programmable logic controller [PLC] · CPC title