Method for the production of heat exchangers

A method for the production of a heat exchanger comprising the steps of:

• casting a mold forming material in a fluid state into continuous, three-dimensional cavities in plastic patterns to produce pattern-retaining molds;
• assembling a plurality of said pattern-retaining molds with a heat-transmitting pipe shaped beforehand into a substantially serpentine form in such a manner that said pattern-retaining molds enclose said heat-transmitting pipe with suitable spacing intervals defined between said pattern-retaining molds themselves and between said pattern-retaining molds and said heat-transmitting pipe;
• removing by heating said plastic patterns from said pattern-retaining molds to produce a fin block mold formed therein with continuous, three-dimensional cavities;
• casting by introducing molten metal under pressure into said continuous, three-dimensional cavities in said fin block mold and into said spacing intervals and allowing said molten metal to solidify;
• and
• removing the material of said fin block mold, thereby producing said heat exchanger in which a porous metal block formed with continuous, three-dimensional pores and fin plates connected to said porous metal block which are unitarily secured to said heat-transmitting pipe.