Abstract: In a heat exchanger with double-walled tubes, an end junction between inner tube and outer tube comprises an end plate in which there is a seat in which an end portion of the inner tube is housed. The corresponding outer tube is peripherally fixed sealingly around the opening of the seat and a deflector extends the inner wall of the outer tube inside the seat so as to define a toroidal cavity between the deflector and a side wall of the seat. The seat is closed by a bottom which is opposite to the opening of the seat and which has a passage connected sealingly to the end of the inner tube in the seat for the transit of the fluid to be cooled. A radial space is present near the said bottom between the toroidal cavity and internal cavity of the double-walled tube, and the end plate has at least one conduit which emerges inside the toroidal cavity for the inflow or outflow of the cooling fluid.

Abstract: In a heat exchanger with double-walled tubes, an end junction between inner tube and outer tube comprises an end plate in which there is a seat in which an end portion of the inner tube is housed. The corresponding outer tube is peripherally fixed sealingly around the opening of the seat and a deflector extends the inner wall of the outer tube inside the seat so as to define a toroidal cavity between the deflector and a side wall of the seat. The seat is closed by a bottom which is opposite to the opening of the seat and which has a passage connected sealingly to the end of the inner tube in the seat for the transit of the fluid to be cooled. A radial space is present near the said bottom between the toroidal cavity and internal cavity of the double-walled tube, and the end plate has at least one conduit which emerges inside the toroidal cavity for the inflow or outflow of the cooling fluid.

Abstract: A heat exchanger includes a pressurized shell and a tube bundle with exchanging tubes between flexible tubesheets. The flexible tubesheets are reciprocally interconnected by tie rods in a central zone of the flexible tubesheets which is devoid of exchanging tubes. The exchanging tubes in the tube bundle are arranged around the tie rods. The heat exchanger may further include conveying diaphragms arranged along the tube bundle. The conveying diaphragms may be shaped, alternately, as discs and rings.

Abstract: A heat exchanger with a pressurised shell and a tube bundle with exchanging tubes between flexible tubesheets has the flexible tubesheets reciprocally interconnected by tie rods in a central zone of the tubesheets which is devoid of exchanging tubes and the exchanging tubes in the tube bundle are arranged around such tie rods. The exchanger may further comprise conveying diaphragms arranged along the bundle shaped, alternately, as discs and rings.