GB486113A - Improvements in methods of producing foam - Google Patents

Abstract

A lasting foam is produced by dissolving a foaming agent in a mobile liquid such as water, adding solid particles, of more than colloidal dimensions, which do not react with or dissolve in the liquid, and then dispersing a gas in the liquid so as to form the foam and disperse the solid particles in the foam. The particles may consist of finely ground alumina or, for fire-extinguishing, of ground limestone or sodium bicarbonate. The solid particles may have fertilizing, weed-killing, or pest - combating properties; for example, sulphur or copper arsenate powder may be used, and copper-lime liquor may be used as the liquid. For curative baths, powdered sulphur and/or alumina may be used. British Specification 263,812, [Class 47 (ii)], and U.S.A. Specification 1,971,997 are referred to. The Specification as open to inspection under Sect. 91 refers also to the use of foam as a carrier for solids which are to react with gases for the purpose of absorption or of separating fluid or solid constituents, and states that gases for reaction, such as cyanogen or oxygen, may be employed in making the foam. Gases may be purified by means of a foam containing lime or calcium bicarbonate. Powdered solids may be added to foam produced chemically by the reaction of aluminium sulphate or sodium bisulphate with sodium potassium bicarbonate or carbonate. The gas for foam production may be derived from the reaction of carbides or hydrides with water. This subject-matter does not appear in the Specification as accepted.ALSO:A lasting foam is produced by dissolving a foaming agent in a mobile liquid such as water, adding solid particles, of more than colloidal dimensions, which do not react with or dissolve in the liquid, and then dispersing a gas in the liquid so as to form the foam and disperse the solid particles in the foam. The particles may consist of finely ground alumina or, for fire-extinguishing, of ground limestone or sodium bicarbonate. The solid particles may have fertilizing, weed-killing, or pest combating properties; for example, sulphur or copper arsenate powder may be used, and copper-lime liquor may be used as the liquid. For curative baths, powdered sulphur and/or alumina may be used. British Specification 263,812, [Class 47 (ii)], and U.S.A. Specification 1,971,997 are referred to. The Specification as open to inspection under Sect. 91 refers also to the use of foam as a carrier for solids which are to react with gases for the purpose of absorption or of separating fluid or solid constituents, and states that gases for reaction, such as cyanogen or oxygen, may be employed in making the foam. Gases may be purified by means of a foam containing lime or calcium bicarbonate. Powdered solids may be added to foam produced chemically by the reaction of aluminium sulphate or sodium bisulphate with sodium potassium bicarbonate or carbonate. The gas for foam production may be derived from the reaction of carbides or hydrides with water. This subject-matter does not appear in the Specification as accepted.