Time determinate fire protection blanket

摘要

A fire protective blanket construction providing multiple time protection for application to electrical conduit and cable trays to preserve operation of electrical circuitry carried by the cables in the event of exposure to fire. Comprising the prefabricated fire resistant blanket are back-to-back blanket sections separated by a moisture impervious metal foil. Disposed within the outer of the blanket section on the exterior side of the foil is a transversely extending envelope containing a selected thickness of trihydrated alumina in powdered form. When exposed to high temperature, the trihydrated alumina emits a steam vapor for protecting the article to which the blanket has been applied for a time period correlated to the thickness and other thermal properties of the individual elements comprising the blanket.