Patent ID: 7140425

Claim:
A plate-tube type heat exchanger comprising a plurality of extruded profile flat or wavy plates each having a plurality of channels running parallel along the plate, attachment means extending from both sides of each channel forming therewith a “U” shape in cross section; and a plurality of tubes housed and secured in said channels, thus forming a circuit for the circulation of a heating fluid, a refrigeration fluid or heating means; wherein said attachment means associated to each channel, in their closed position, cover together with its corresponding channel, almost fully the external surface of the tube housed in said channel, thereby securing each one of the tubes to each one of said plates without the use of welding; said plates including coupling means of the male-female type in their ends wherein the male end of one of them is introduced into the female end of the other, which closes thereafter by means of pressure, in order to firmly join each other without using welding, to form a heat exchanger wherein the plates joined to each other with secured tubes, include a folding at a specific distance through its cross section, at an angle of about 90° or about 180°, forming a coil or snail shaped structure, wherein the spacing distance between segments of the plates located at each side of said folding is between 20 mm and 30 mm, forming a heat exchanger not requiring maintenance.