GB854730A - Dry powder dispersing device - Google Patents

Abstract

854,730. Dry powder dispersing devices; fire extinguishing. FEDERAL LABORATORIES Inc. July 24, 1959, No. 25449/59. Classes 47 and 119. [Also in Group XVII] A dispersing device for dry powder, e.g. tear gas dust, fire-fighting chemicals at surfacecoating materials, comprises a cylinder 10 Fig. 1 having puncturing tubes 44, 46, 48 arranged at one end for puncturing a can 40 of dry powder when a movable support 38 for the can is moved towards the tubes, one tube 48 being connected to a supply 30 of gas under pressure while another tube 44 connects with an outlet passage 50 so that gas under pressure can be circulated in the punctured can and discharged therefrom laden with powder. The third tube 46 has a safety outlet to atmosphere which is covered by a disc adapted to rupture only under excess gas pressure. As shown in Fig. 1, the support for the can comprises a piston 38 which is moved upwardly by gas pressure from the supply 30 via a tube 68 and fitting 70 leading into the bottom of the cylinder 10. This upward movement causes the can to be punctured and uncovers a port 66 connected by a passage 62 to the inlet tube 48, thus permitting the gas to enter the punctured can. In another embodiment the supply 30, Fig. 4, is connected directly with the inlet tube 48, the cylinder 110 has no integral bottom wall and the can support 140 serves as a bottom wall cover which is moved upwardly by a screw and threaded spider arrangement 162, 150 to puncture the can and seal the bottom of the cylinder 110. Gas is then supplied from the supply 30. The device may be pivotally mounted at 24 Fig. 1 on a pair of fork arms 26 forming part of a bracket 28 of a wheeled truck, e.g. on the rear bumper. The tear gas agent used may be chloracetophenone.