Method of Obtaining or Maintaining Optical Transmittance into Boiler Liquid

Patent metadata

Field	Value
Publication number	US-2016201896-A1
Application number	US-201514596691-A
Country	US
Kind code	A1
Filing date	Jan 14, 2015
Priority date	Jan 14, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

A clean-in-place method of maintaining optical transference through a light transference medium operably connected to a boiler system is disclosed. The method comprises inter alia contacting a liquid chemical agent to a wetted surface of a light transference medium. The liquid chemical agent is selected from the group consisting of an acid, a chelant, a reducing agent, and combinations thereof, for a period of time and at a concentration sufficient to clean the wetted surface of the light transference medium.

First claim

1 - 14 . (canceled)

15 . A clean-in-place method of maintaining optical transference through a light transference medium operably connected to a boiler system, the method comprising:
contacting a stream of boiler liquid with a wetted surface of a light transference medium in optical communication with an optical sensor; inputting data related to a parameter of the boiler liquid measured by the optical sensor to a control scheme of a boiler system; electronically isolating the optical sensor from the control scheme while maintaining control of the boiler system based on the input data related to the parameter of the boiler liquid; contacting a liquid chemical agent to the wetted surface of the light transference medium, the liquid chemical agent comprising a component selected from the group consisting of an acid, a chelant, a reducing agent, and combinations thereof, for a period of time and at a concentration sufficient to clean the wetted surface of the light transference medium; and electronically de-isolating the optical sensor from the control scheme.

16 . The clean-in-place method of claim 15 , wherein the component is an acid selected from the group consisting of: urea hydrochloride, hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, citric acid, carbonic acid, bicarbonic acid, sulfamic acid, and combinations thereof.

17 . The clean-in-place method of claim 16 , wherein the acid is present in the liquid chemical agent at a concentration of from about 5 weight percent to about 98 weight percent acid in aqueous solution.

18 . The clean-in-place method of claim 15 , wherein the component is a chelant selected from the group consisting of: citric acid, oxalic acid, ethylenediaminetetraacetic acid, diethylene triamine pentaacetic acid, an organic phosphonate, salts thereof, and combinations thereof.

19 . The clean-in-place method of claim 18 , wherein the chelant is present in the liquid chemical agent at a concentration of from about 1 weight percent to about 20 weight percent chelant in aqueous solution.

20 . The clean-in-place method of claim 15 , wherein the component is a reducing agent selected from the group consisting of: an acid sulfite, an acid bisulfate, an acid hydrosulfite, an acid phosphite, phosphoric acid, oxalic acid, formic acid, ascorbic acid, erythorbic acid, salts thereof, and combinations thereof.

21 . The clean-in-place method of claim 20 , wherein the reducing agent is present in the liquid chemical agent at a concentration of from about 0.1 weight percent to about 10 weight percent reducing agent in aqueous solution.

22 . The clean-in-place method of claim 15 , wherein the liquid chemical agent comprises an acid of one chemical species and a chelant of a second chemical species.

23 . The clean-in-place method of claim 15 , wherein the liquid chemical agent comprises a reducing agent of one chemical species and a chelant of a second chemical species.

24 . The clean-in-place method of claim 15 , further comprising applying ultrasonic energy into the liquid chemical agent during at least a portion of the contacting of the liquid chemical agent to the wetted surface of the light transference medium.

25 . The clean-in-place method of claim 15 , wherein the liquid chemical agent contacts the wetted surface of the light transference medium at a flow rate of about 1 L/min to about 40 L/min at a concentration of about 0.1 weight percent to about 80 weight percent.

26 . A clean-in-place method of maintaining optical transference through a light transference medium operably connected to a boiler system, the method comprising:
flowing a stream of boiler liquid to contact a wetted surface of a light transference medium in optical communication with an optical sensor; inputting data related to a parameter of the boiler liquid measured by the optical sensor to a control scheme of a boiler system; discontinuing the flow of the stream of boiler liquid to contact the wetted surface of the light transference medium; electronically isolating the optical sensor from the control scheme while maintaining control of the boiler system based on the input data related to the parameter of boiler liquid; contacting a liquid chemical agent to the wetted surface of the light transference medium, the liquid chemical agent comprising a component selected from the group consisting of an acid, a chelant, a reducing agent, and combinations thereof, for a period of time and at a concentration sufficient to clean the wetted surface of the light transference medium; removing the liquid chemical agent from the wetted surface of the light transference medium; resuming the flow of the stream of boiler liquid to contact the wetted surface of the light transference medium; and electronically de-isolating the optical sensor from the control scheme.

27 . The clean-in-place method of claim 26 , wherein the component is an acid selected from the group consisting of: urea hydrochloride, hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid, citric acid, carbonic acid, bicarbonic acid, sulfamic acid, and combinations thereof.

28 . The clean-in-place method of claim 27 , wherein the acid is present in the liquid chemical agent at a concentration of from about 5 weight percent to about 98 weight percent acid in aqueous solution.

29 . The clean-in-place method of claim 25 , wherein the component is a chelant selected from the group consisting of: citric acid, oxalic acid, ethylenediaminetetraacetic acid, diethylene triamine pentaacetic acid, an organic phosphonate, salts thereof, and combinations thereof.

30 . The clean-in-place method of claim 29 , wherein the chelant is present in the liquid chemical agent at a concentration of from about 1 weight percent to about 20 weight percent chelant in aqueous solution.

31 . The clean-in-place method of claim 26 , wherein the component is a reducing agent selected from the group consisting of: an acid sulfite, an acid bisulfate, an acid hydrosulfite, an acid phosphite, phosphoric acid, oxalic acid, formic acid, ascorbic acid, erythorbic acid, salts thereof, and combinations thereof.

32 . The clean-in-place method of claim 31 , wherein the reducing agent is present in the liquid chemical agent at a concentration of from about 0.1 weight percent to about 10 weight percent reducing agent in aqueous solution.

33 . The clean-in-place method of claim 26 , wherein the period of time is from about 1 minute to about 10 minutes.

34 . The clean-in-place method of claim 26 , wherein the liquid chemical agent comprises a reducing agent of one chemical species and a chelant of a second chemical species.

35 . The clean-in-place method of claim 26 , further comprising applying ultrasonic energy into the liquid chemical agent during at least a portion of the contacting of the liquid chemical agent to the wetted surface of the light transference medium.

36 . The clean-in-place method of claim 26 , wherein the liquid chemical agent is removed by the resuming step.

Assignees

• Ecolab Usa Inc

Inventors

• Hicks Peter D
• Li Hui
• Bradley Michael E
• Murcia Michael J
• Banks Rodney H
• Schwartz Joe L

Classifications

• F22B37/38 Primary

  Determining or indicating operating conditions in steam boilers, e.g. monitoring direction or rate of water flow through water tubes · CPC title

• F28G15/003

  Control arrangements · CPC title

• F28G9/00

  Cleaning by flushing or washing, e.g. with chemical solvents (appliances using jets of fluid for removing debris F28G1/16, F28G3/16) · CPC title

• F22B37/56

  Boiler cleaning control devices, e.g. for ascertaining proper duration of boiler blow-down · CPC title

• F22B37/486

  Devices for removing water, minerals or sludge from boilers (F22B37/483, F22B37/50, F22B37/52 and F22B37/54 take precedence) · CPC title