GB846221A - Explosion suppressing system - Google Patents

Abstract

846,221. Explosion suppressing systems. SPECIALTIES DEVELOPMENT CORPORATION. Nov. 24, 1958, No. 37730/58. Class 47. In an explosion suppressing system wherein a stored explosion suppressing medium is released in the vicinity of the explosion hazard in response to the occurrence of a predetermined rate of pressure rise at the incipience of an explosion, an electrically controlled device for effecting release of the medium is energized from a network which includes a piezoelectric pressure transducer having a rate of pressure rise characteristic located in the vicinity of the hazards. In Fig. 1 a fuel tank 10 is provided therein with a receptacle 11 containing explosion suppressing medium 12 adapted to be released when an explosive substance 15 is ignited by a filament 14 connected in the anode circuit of a triode valve 19, preferably of the thyratron type, which is controlled by a piezoelectric transducer 16 located in the fuel tank 10. The pressure transducer 16 comprises a holder 20 of iron, lead &c, a crystal 21 attached to the holder and a pressure plate 22, e.g. of metal foil attached to the crystal, contained in a casing 23 having openings &c, to enable the transducer to sense the pressure within the hazard zone. The crystal preferably has a high capacitance and may be a ceramic type composed of barium titanate, calcium titanate, barium-calcium titanate or lead zirconate. Other types of crystal may be employed in conjunction with a condenser. The network may include a variable resistance to predetermine the rate of pressure rise characteristic and a temperature compensating thermistor device, Fig. 3 (not shown). A fire extinguishing and/or fire preventing medium may be used in the place of explosion suppressing medium.