Tube-and-plate heat exchanger

A tube-and-plate heat exchanger for said exchanging heat between first and second heat carriers, said heat exchanger comprising:

• a plurality of tubes through which the first heat carrier flows, the tubes oriented in a parallel array;
• an inlet and an outlet for said second heat carrier;
• and
• a plurality of spaced plates mounted on said tubes, each of said tubes extending through each of said plurality of plates, each pair of adjacent plates defining a passageway between said inlet and said outlet to convey said second heat carrier across said tubes, the cross section of each plate being in the form of alternating depressions and projections in the direction of flow defining a continuous symmetrically waved line, adjacent plates being positioned so that the depressions of one plate are opposite the projections of an adjacent plate, the space between each set of plates defining a passageway having continuous, symmetrical, alternately converging and diverging sections, the diverging sections having an angle of divergence (.psi.) in the direction of flow of said second heat carrier and with respect to the axis of the passageway selected to be greater than the critical angle at which the loss in hydrodynamic stability of the laminar structure of the second heat carrier flow occurs, each of the plates including rectilinear sections between adjacent depressions and projections, the projections and the depressions of the spaced plates being in continuous relationship and the rectilinear sections having the same angle (.phi.) of inclination to the axis of symmetry of the wave line outlining the cross section of the spaced plate, which angle equals halve the angle (.psi.) of divergence, wherein the projections and the depressions of the spaced plates have an inner radius (R) of bending between one and twenty times the thickness (.delta.) of the material of the spaced plate.