Method for preventing the ignition of fire-damp and coal dust during mine blasting

摘要

422,255. Blasting - charges. DE WENDEL ET CIE, LES PETITS FILS DE F., 3, Rue Paul Baudry, Paris. March 15, 1934, No. 8169. Convention date, April 8, 1933. Drawings to Specification. [Class 9 (i)] [See also Group XIII] Carbon dioxide in the form of snow is introduced in an uncovered state into a blast hole in front or behind a blasting-cartridge, so that the gaseous carbon dioxide clears the hole from fire-damp even to a certain extent in the surrounding ground, thereby preventing firedamp explosion. Cartridges containing water or substances saturated with water may also be inserted. The carbon dioxide is stored and carried in receptacles having a vacuum between double walls and provided with an internal lining of felt or wool. Specification 15495/08, [Class 47], is referred to for the use of solid carbon dioxide in blast holes. Specification 409,201 also is referred to.