Method and device for maintaining a clean atmosphere at controlled temperature at a workstation

A method of maintaining a clean atmosphere at controlled temperature at a workstation (1), said workstation (1) being accessible from a zone containing contaminants through at least one opening (5), said opening having a width and a length, which comprises generating a curtain of gas at the level of said opening (5) by means of a slow jet and a fast jet, the slow jet having an inner cone of range equal to the width of said opening (5), said slow jet having a flow rate, said fast jet having an external face, an internal face and a flow rate, said internal face being in contact with the slow jet, said flow rate of said fast jet being induced by said internal face and being equal to the injection flow rate of said slow jet, said slow jet and said fast jet covering the entire length of said opening (5), said fast jet being situated at the level of said opening (5) on the workstation side (1), said slow jet and fast jet being directed approximately in parallel to the opening (5) whereby at least said external face of the fast jet reaches up to said opening (5), and generating a stream of clean gas on the workstation (1) under a controlled temperature, in a direction opposite to the entry of said contaminants, said stream of clean gas sweeping uniformly over said workstation (1), the flowrate of said stream being at least equal to the flowrate induced by said external face of the fast jet.