Heat detection and alarm system

Abstract

A pressurized source of fluid, either liquid or gas, is supplied through a supply conduit system to a main heat sensitive conduit fabricated from a thermoplastic material and having sealed end portions positioned adjacent a potential source of fire or undesirably high temperature. A plurality of branch heat sensitive conduits are connected to the main conduit and extend therefrom into substantially abutting relation with the object to be monitored. The supply conduit system maintains a selected fluid pressure within the heat sensitive conduits which are operable to soften and rupture at a preselected temperature, as determined by the system pressure and the diameter and wall thickness of the heat sensitive conduits. When exposed to the excessive preselected temperature, the conduits rupture. A pressure switch connected to the supply conduit system is responsive to a decrease in the fluid pressure and is operable to complete an electrical circuit between an electrical power source and an alarm device for actuating the alarm. Actuation of the alarm device indicates the existence of an undesirably high temperature and may initiate an automatic shutdown procedure. The pressurized fluid may contain a fire retardant material which, upon rupture of any one of the heat sensitive conduits, is discharged to either reduce an undesirably high temperature or extinguish a fire simultaneously with actuation of the alarm.