Rotary heat exchange apparatus provided with a spherically coiled heat transfer tube

In a heat exchange apparatus for heating or cooling a fluid which comprises:

• a vessel;
• a rotary heat exchanger within said vessel, said rotary heat exchanger comprising a reflux-type, heat transfer, double-tube comprising an outer tube which is closed at the front end thereof and has a heat-transfer-medium inlet at the rear end thereof, an inner tube provided concentrically within said outer tube, the front end of said inner tube having an opening located near the closed front end of said outer tube, said outer tube having an annular partition around said opening, the rear end of said inner tube extending beyond the rear end of said outer tube and defining a heat-transfer-medium outlet, driving means for rotating said outer tube, a spherically coiled heat transfer bypass tube provided concentrically around said outer tube along a lengthwise part thereof, one end of said bypass tube communicating with said outer tube at a location upstream of said partition, the other end of said bypass tube communicating with said opening of said inner tube located near the front end of said outer tube, said spherically coiled heat transfer bypass tube being formed by spirally coiling or convoluting an elongated tube concentrically around said outer tube in a spherically-contoured shape, and a suction tube mounted concentrically on and surrounding said outer tube, said suction tube being open at its opposite ends and being located within the spherical space enveloped by said spherically coiled heat transfer bypass tube, said suction tube and said spherically coiled heat transfer bypass tube being integral with said outer tube so as to rotate in unison therewith, whereby a heat transfer medium can flow in series through said outer tube, said spherically coiled bypass tube and said inner tube, in that order.