AQUEOUS CLEANING SOLUTION FOR REMOVAL OF ROUGING DEPOSITS ON MEDIA-CONTACTED SURFACES OF STAINLESS STEELS, USE THEREOF AND PROCESS FOR PRODUCTION THEREOF

    公开(公告)号:US20220056381A1

    公开(公告)日:2022-02-24

    申请号:US17390977

    申请日:2021-08-01

    申请人: Beratherm AG

    摘要: An aqueous cleaning solution for removing rouging deposits on media-contacted surfaces of stainless steels comprises a first component and a second component. The first component is an alkali sulfite and the second component is an alkali formate, wherein the concentrations thereof are adjusted in such manner that formate is present in a molar ratio of 1.5 to 4.2 relative to sulfite, and that the pH value of the cleaning solution is 4.0 to 4.8. For preparing the aqueous cleaning solution, an aqueous solution of an alkali hydroxide is provided initially, thereafter a first amount of concentrated aqueous formic acid is admixed in an excess in such manner that a pH value of 3.5 to 4.5 is established, then a second amount of solid alkali sulfite is admixed in accordance with the sulfite concentration to be established, thus resulting in a pH value of 5.5 to 6.5, and finally a third amount of concentrated aqueous formic acid is admixed until a pH value of 4.0 to 4.8 is attained.

    AQUEOUS CLEANING SOLUTION FOR REMOVAL OF ROUGING DEPOSITS ON MEDIA-CONTACTED SURFACES OF STAINLESS STEELS, USE THEREOF AND PROCESS FOR PRODUCTION THEREOF

    公开(公告)号:US20180371379A1

    公开(公告)日:2018-12-27

    申请号:US15753333

    申请日:2016-08-19

    申请人: Beratherm AG

    摘要: An aqueous cleaning solution for removing rouging deposits on media-contacted surfaces of stainless steels comprises a first component and a second component. The first component is an alkali sulfite and the second component is an alkali formate, wherein the concentrations thereof are adjusted in such manner that formate is present in a molar ratio of 1.5 to 4.2 relative to sulfite, and that the pH value of the cleaning solution is 4.0 to 4.8. For preparing the aqueous cleaning solution, an aqueous solution of an alkali hydroxide is provided initially, thereafter a first amount of concentrated aqueous formic acid is admixed in an excess in such manner that a pH value of 3.5 to 4.5 is established, then a second amount of solid alkali sulfite is admixed in accordance with the sulfite concentration to be established, thus resulting in a pH value of 5.5 to 6.5, and finally a third amount of concentrated aqueous formic acid is admixed until a pH value of 4.0 to 4.8 is attained.