Patent GB-1046966-A (GB)
Title: Improvements in or relating to filter treating processes
IPC: B01D41/04
Filed: 1963-08-26
Abstract: A composition suitable for cleaning filter blankets, e.g filter blankets made from "Dacron" (Registered Trade Mark) used in sewage disposal plants, comprises (a) a quaternary ammonium salt containing at least one alkyl group of 10-18 carbon atoms, (b) an alkyl primary amine salt containing 10-18 carbon atoms in the alkyl substituent and (c) a quaternary ammonium compound having at least one alkyl group of 10-18 carbon atoms and containing 2-25 moles of an alkylene oxide substituent having 2-4 carbon atoms.  The anion of the quaternary ammonium salt (a) may be a chloride or nitrite radical.  The amine salt (b) may be the hydrochloride, acetate, nitrite, sulphate, hydrobromide or hydroiodide.  The anion of the quaternary ammonium compound (c) may be a chloride or methyl sulphate radical. The components (a), (b), and (c) may be present in the composition in about equal proportions. The composition may be prepared by first forming a solution of the amine salt (b) in an isopropanol or isopropanol-water solution and then adding the other two components prior to diluting with water to apply it to the filter blanket.  In the examples a composition comprising hydrogenated tallow trimethyl ammonium chloride, dodecylamine hydrochloride and hydrogenated tallow bis-(2-hydroxy propyl) methyl ammonium methyl sulphate is used.ALSO:Filter blankets, e.g. filter blankets made from "Dacron" (Registered Trade Mark) used in sewage disposal plants, are cleaned and proofed against fungi and bacteria by treating them for a period in excess of an hour with a composition comprising (a) a quaternary ammonium salt containing at least one alkyl group of 10-18 carbon atoms, (b) an alkyl primary amine salt containing 10-18 carbon atoms in the alkyl substituent and (c) a quaternary ammonium compound having at least one alkyl group of 10-18 carbon atoms and containing 2-25 moles of an alkylene oxide substituent having 2-4 carbon atoms. They may then be rinsed with water.  The anion of the quarternary ammonium salt (a) may be a chloride or nitrite radical.  The amine salt (b) may be the hydrochloride, acetate, nitrate sulphate, hydrobromide or hydroiodide.  The anion of the quarternary ammonium compound (c) may be a chloride or methyl sulphate radical.  The components (a), (b), and (c) may be present in the composition in about equal proportions.  The composition may be prepared by first forming a solution of the amine salt (b) in an isopropanol or isopropenol-water solution and then adding the other two components prior to diluting with water to apply it to the filter blanket.  The solution may be applied to the blanket by spraying or immersion.  The blanket may be treated in situ on the filter drum by revolving the drum in the filter pan containing the treating solution and then rinsing with water.ALSO:Filter blankets, e.g. filter blankets made from "Dacron" (Registered Trade Mark) used in sewage disposal plants, are cleaned and proofed against fungi and bacteria by treating them for a period in excess of an hour with a composition comprising (a) a quaternary ammonium salt containing at least one alkyl group of 10-18 carbon atoms, (b) an alkyl primary amine salt containing 10-18 carbon atoms in the alkyl substituent and (c) a quaternary ammonium compound having at least one alkyl group of 10-18 carbon atoms and containing 2-25 moles of an alkylene oxide substituent having 2-4 carbon atoms. They may then be rinsed with water.  The anion of the quarternary ammonium salt (a) may be a chloride or nitrite radical.  The amine salt (b) may be the hydrochloride, acetate, nitrite sulphate, hydrobromide or hydroiodide.  The anion of the quarternary ammonium compound (c) may be a chloride or methyl sulphate radical.  The components (a), (b), and (e) may be present in the composition in about equal proportions.  The composition may be prepared by first forming a solution of the amine salt (b) in an isopropanol or isopropanol-water solution and then adding the other two components prior to diluting with water to apply it to the filter blanket.  The solution may be applied to the blanket by spraying or immersion.  The blanket may be treated in situ on the filter drum by revolving the drum in the filter pan containing the treating solution and then rinsing with water.ALSO:Filter blankets, e.g. filter blankets made from "Dacron" (Registered Trade Mark) used in sewage disposal plants, are cleaned and proofed against fungi and bacteria by treating them for a period in excess of an hour with composition comprising (a) a quaternary ammonium salt containing at least one alkyl group of 10-18 carbon atoms, (b) an alkyl primary amine salt containing 10-18 carbon atoms in the alkyl substituent and (c) a quaternary ammonium compound having at least one alkyl group of 10-18 carbon atoms and containing 2.25 moles of an alkylene oxide substituent having 2-4 carbon atoms. They may then be rinsed with water.  The anion of the quaternary ammonium salt (a) may be a chloride or nitrite radical.  The amine salt (b) may be the hydrochloride, acetate, nitrite sulphate, hydrobromide or hydroiodide.  The anion of the quaternary ammonium compound (c) may be a chloride or methyl sulphate radical.  The components (a), (b), and (c) may be present in the composition in about equal proportions.  The composition may be prepared by first forming a solution of the amine salt (b) in an isopropanol or isopropanol-water solution and then adding the other two components prior to diluting with water to apply it to the filter blanket.  The solution may be applied to the blanket by spraying or immersion.  The blanket may be treated in situ on the filter drum by revolving the drum in the filter pan containing the treating solution and then rinsing with water.