Heat exchanger

A heat exchanger for transferring heat energy between first and second fluid heat exchange media, comprising:

• an elongated outer pressure jacket provided with an entry connection at one end of the outer pressure jacket for the supply of the first heat exchanger medium and an exit connection at said one end for the removal of the first heat exchange medium;
• U-shaped pipes positioned within the pressure jacket and affixed in a pipe-supporting floor that is connected with the pressure jacket at an opposite end of said outer pressure jacket;
• a guide jacket surrounding the U-shaped pipes and radially spaced apart from an inside wall of the pressure jacket and defining an annular space therewith, inner and outer legs of the U-shaped pipes being respectively positioned on one of two concentric partial circles;
• an inlet fitting on said pressure jacket communicating with the legs of said U-shaped pipes along one of said partial circles and an outlet fitting on said pressure jacket communicating with the legs of said U-shaped pipes along the other of said partial circles for passing said second heat exchange medium through said U-shaped pipes;
• a central pipe extending along the longitudinal axis of the heat exchanger, connected with the entry connection, opening at an open end towards the interior of the heat exchanger, and extending from said one end of said outer pressure jacket to a location close to the pipe-supporting floor, the inner legs surrounding said central pipe;
• a separating jacket between the inner and outer legs of the U-shaped pipes and connected to the pipe-supporting floor, the guide jacket being sealingly connected at one end thereof with the central pipe and having an open end lying close to the pipe-supporting floor;
• a valve chamber formed on an input end of the central pipe remote from said open end thereof, said valve chamber being formed with opposite first and second openings, the first opening communicating between the central pipe and said entry connection, the second opening communicating between said entry communication and the interior of the pressure jacket;
• and
• a valve plate in the valve chamber and axially movable in the valve chamber to selectively close one of the openings.