Abstract: A flue terminal extractor mounted at the discharge end of a flue comprises a lower unit mounted coaxially on the flue and an upper unit coaxial with and spaced from the lower unit. The lower unit comprises a downwardly facing frustoconical lower base having a central opening through which the flue extends and an upwardly facing frustoconical lower bonnet joined at its outer periphery with the outer periphery of the lower base and having a central opening in which the flue terminates. The upper unit comprises a downwardly facing conical upper base and an upwardly facing conical upper bonnet. The area of the free space for outward flow of gas between the lower unit and the upper unit is at least equal to the cross sectional area of the flue.

Abstract: This suction arm for gaseous fluids comprises a tubular articulated conduit consisting of at least one flexible sleeve (5) disposed between two rigid tubes (8). These tubes (8) are interconnected at either end of the flexible intermediate sleeve (5) by mechanical holding means (9) comprising each at least one pair of first and second members (10a, 10b) pivotally interconnected centrally of the flexible sleeve and rigidly assembled in side by side relationship by distance-pieces (15) under the control of a spiral return spring (13) and detent-positioning means (16, 17, 18), whereby the two rigid tubes (8, 8) are constantly urged to their relative angular position matching that of the ends of the intermediate flexible sleeve (5).

Abstract: An aspirating device for the ejection of gases or fumes has dynamic primary and static secondary extraction means. The static secondary means has lower and upper elements configured in pseudo-frustoconical forms. The upper and lower elements are rigidly fixed to one another. The dynamic primary means are active or passive dependent on the desired level of flow of the ejected fluid.