Abstract: A swirl-generating helical agitator for tubular heat-exchangers comprises a strip of material twisted into a helix and has a cross-section including opposed double inflections. The double inflections have lateral portions inclined at an angle of inclination with respect to and on either side of a central portion.

Abstract: A header of plastic material for a heat exchanger of the tube type has two identical faces provided with projecting ribs. The internal partition-wall of a water box is fitted between the ribs of one header face while the ribs of the other face are applied against an end fin of the tube bank.

Abstract: In an air-conditioner or heater for a motor vehicle cabin, the casing (10) housing the heat exchanger (12) proper essentially comprises an air inlet duct (26) leading to the upstream face (22) of the heat exchanger and an air outlet duct (28) leading away from the downstream face (24) of the heat exchanger. A baffle wall (38) extends adjacent to the downstream face (24) to hinder the flow of air through portions of the heat exchanger where it would otherwise flow fastest. This increases the overall efficiency of the heat exchanger.

Abstract: In a heat exchanger with fluid flow tubes, a degassing device formed in a water box of the exchanger, said water box including first and second collecting chambers and a compensation chamber, communicating with the outlet pipe of the exchanger, and a narrow passage connecting the upper portion of the first collecting chamber with the compensation chamber by forming a siphon between said two chambers.

Abstract: A side sealing device comprises a plate (22) which covers one side (18) of the tube bundle constituting the heat exchanger. It is snap-fitted to the bundle by suitable end tabs (32) for engaging the ends of the tubes of like projections. The invention is particularly applicable to heat exchangers for motor vehicles.

Abstract: A one-piece turbulator comprising a rectangular frame with two laterally spaced parallel bars having corresponding ends interconnected by end cross bars, and cross-pieces in the frame. The cross-pieces have a portion extending between the parallel bars, and a further portion projecting perpendicular to a plane defined by the axes of the parallel bars.

Abstract: A sealed joint between a basin (21) and a plate (43) as in the construction of a heat exchanger tank. The basin has a rim with an outwardly directed flange (23), and the plate has a rim including a U-shaped channel (42) to receive the flange together with a gasket (65). The gasket comprises at least a fillet which is suitable for being elastically deformed by being compressed between the flange and the channel to fill the space therebetween. The portion (100) of the fillet which faces the flanges is narrower than the portion (100') of the fillet which faces the channel by virtue of at least one setback (104) in the fillet between said portions thereof.

Abstract: A turbulence agitator placed, for example, in the tube of a heat exchanger, comprises at least one continuous helical thread. The section through the agitator in any plane passing through the axis of the helix has a central portion and teeth of the same shape and dimensions, spaced along the said axis. Each of these teeth is asymmetrical in relation to a line perpendicular to the axis of the helix.

Abstract: In a heat exchanger or radiator for an engine-cooling circuit, a device forming a water box and an expansion chamber which are made in a single piece by moulding, but which are formed as separate containers that do not share a common partition, although they may be held together by a thin strip of material (27). The containers are of cylindrical or semi-cylindrical shape for strength.

Abstract: In a heat exchanger, e.g. a radiator for a motor vehicle, the water box (10) and the expansion chamber (11) are made in a single plastic moulding, and are divided by a common wall (12) having at least one orifice for liquid communication therebetween. The expansion chamber tapers from a wider bottom to a narrower top. The narrower top has a filler cap, while the wider bottom is closed by an add-on cover.

Abstract: The heat exchanger (10), e.g. a motor vehicle radiator, has a bundle of thin-walled metal tubes (12) passing through a perforated plate or collector (18) via holes (23) therethrough. The collector plate is made with holes having walls that are highly elastic, either by the collector being molded from a highly elastic plastic, or by the collector plate being made from a sheet of metal with the holes being formed with spring shaped rims. The elasticity is used to grip and seal the tubes (12) in the holes (23) through the collector plate, and the relative strengths of the tubes and the plate are such that the portions (38, 61, 92) of the tubes thus elastically gripped in said holes are contracted by the elastic grip and are flanked on either side by non-contracted portions (42, 41; 66, 74; 93, 94) of tube which ensure that the tubes are held fast against longitudinal movement in either direction relative to the collector plate.

Abstract: A heat exchanger for an engine cooling circuit, comprising first and second liquid circuits formed in parallel in the exchanger, and a temperature sensitive valve for controlling the flow of liquid through said circuits, wherein passages formed between both circuits are adapted to be closed and opened by a single sealing member on which act the said valve and a return spring.

Abstract: A heat exchanger, such as the radiator of a motor vehicle, has a nest of tubes through which liquid flows. To improve heat exchange between the liquid and the tube walls, turbulators (18) are inserted into the tubes to make the liquid flow turbulently. One form of turbulator is U-shaped and has two legs, each of which is inserted into a respective one of the tubes in the nest, via downstream ends (12) thereof. To avoid the liquid flow removing the turbulators from the tubes, stops or projections (19) are provided on either side of the bend in the turbulators. The projections may be moulded integrally with the water box which caps the downstream end of the nest of heat exchange tubes.

Abstract: A connecting device for assembling a collector traversed by the tubes of a tube bundle in a heat exchanger with the housing for the liquid flowing in the tubes, comprising an elastomeric sheet on the collector face opposite to the housing, wherein said elastomeric sheet comprises a marginal bulging portion projecting inwardly of the housing and cooperating with the edge of a trough located in said housing so as to delimit a collecting chamber and an expansion chamber.

Abstract: An expansion tank and water box device for a heat exchanger with a nest of parallel tubes, such as a radiator of a motor vehicle, in which the water box housed inside the expansion tank is maintained by the assembly of the tank with the hollowed plate through which extend the ends of the tubes. Ribs are interposed between the water box and the expansion tank. Said ribs depend, for instance, from the expansion tank.

Abstract: An expansion tank and water box device for a heat exchanger with a nest of parallel tubes, such as a radiator of a motor vehicle, in which the water box housed inside the expansion tank is maintained by the assembly of the tank with the hollowed plate through which extend the ends of the tubes. Ribs are interposed between the water box and the expansion tank. Said ribs depend, for instance, from the expansion tank.