Patent ID: 7631678

Claim:
A hot air device for thermowelding a thermoweldable membrane, comprising: an air inlet for receiving air; a casing in fluid communication with the air inlet; a combustion chamber mounted within the casing and spaced apart therefrom to define a space therebetween, the chamber being delimited by a wall provided with a plurality of perforations allowing the air to flow into the chamber, the chamber comprising: an upstream section; a downstream section; and a fuel injector provided at the upstream section for providing fuel within the chamber; the perforations allowing a portion of the air to flow into the upstream section of the chamber to produce an ignitable air-fuel mixture for producing a flame proximate the fuel injector, and letting the rest of the air entering the casing into the downstream section, whereby the flame is shortened within the chamber and hot air is produced out of the downstream section thereof; an outlet portion in fluid communication with the combustion chamber for receiving the hot air from the combustion chamber and comprising a nozzle through which the hot air is expelled, the nozzle being sufficiently remote from the chamber so as to prevent producing the flame out therefrom; a blower operatively connected to the air inlet to force an airflow from the air inlet through the chamber and out from the nozzle.