| 摘要 |
<p>A heat exchanger for the heating or cooling of a liquid, in particular of a suspension having a high content of solid particles is provided. The heat exchanger includes a container having an inlet for the liquid positioned at one end or at one side of the container and an outlet for the liquid positioned one end of the container; at least one substantially horizontal heat exchange unit being rotatably mounted in the container and comprising two end chambers communicating through a plurality of pipes arranged in a generally annular configuration, the container having, below a horizontal plane through the rotational axis of the heat exchange unit, a circular cylindrical shape to closely conform to the heat exchange unit; means for feeding a heat exchange fluid through the end chambers and the plurality of pipes; a central tube extending concentrically in relation to the rotational axis between the end chambers and being closed-off from them and from the container, the central tube having a diameter not less than 40% of the greatest distance between any two pipes of the heat exchange unit measured at right angles to the rotational axis; and the outlet from the container having a lower edge at a level lower than the uppermost portion of the central tube to maintain the uppermost portion above the free surface level of the liquid in the container. In this way a high relative velocity is obtained even between a viscous suspension and the heat exchanger wall, to provide high heat transfer. Moreover, it is easy to clean the heat transfer wall of deposits.</p> |
