Patent ID: 8847128

Claim:
A heat treatment oven comprising: a loading or treatment zone having a longitudinally extending axis, at least one gas inlet, a gas preheater chamber situated in the oven between the gas inlet and the loading or treatment zone, above or below and in axial alignment along the axis with the loading or treatment zone, the gas preheater chamber having an axial height, a susceptor comprising at least a side wall circumferentially surrounding the preheater chamber and the loading or treatment zone, a field winding suitable for heating the side wall by induction, and a gas distribution plate interposed between and separating the gas preheater chamber and the loading or treatment zone, the gas distribution plate extending transversely to the axis; wherein the side wall of the susceptor terminates in an end portion having a ring that is situated around the preheater chamber, the ring comprising at least two recesses spaced apart circumferentially from one another so as to form portions of reduced thickness in said ring adjacent said preheater chamber, the recesses having an axially extending height less than the axial height of the gas preheater chamber and a radial dimension less than a thickness of said ring in a direction orthogonal to said axis.