Method of Obtaining or Maintaining Optical Transmittance into Boiler Liquid

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.

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.