Heat exchanger and method of producing the same

A regenerative heat exchanger comprising:

• a hermetically sealed gas casing formed with a gas chamber filled with a refrigerant gas and having a center axis, said gas casing having longitudinal end portions along said center axis and formed with first and second ports having said refrigerant gas passing therethrough, said gas chamber of said gas casing having cross-sections taken along planes substantially perpendicular to said center axis thereof and uniform in size and shape with each other;
• and
• a heat exchanging unit having a center axis and a plurality of regenerative plates each having a thickness to have a first flat surface and a second flat surface opposite to said first flat surface, said regenerative plates being situated in face-to-face relationships with one another to have said first and second flat surfaces substantially perpendicular to said center axis of said heat exchanging unit, said heat exchanging unit being received in said gas chamber of the gas casing with said center axis thereof being in coaxial relationship with said center axis of said gas casing, each of said regenerative plates being made of a material having a thermal conductivity and a heat capacity, each of said regenerative plates having a central point and being shaped in the symmetrical outline form with respect to said central point and smaller in size than said cross-sections of said gas chamber of said gas casing, each of said regenerative plates having a plurality of circumferential rib portions each having a width and circumferentially extending along the outline of said regenerative plate, said circumferential rib portions being arranged in concentric relationship with respect to said central point of said regenerative plate and radially spaced apart from one another, each of said regenerative plates having a plurality of radial rib portions each having a width narrower than that of each of said circumferential rib portions and radially extending from said central point thereof and angularly spaced apart from one another, said circumferential rib portions and said radial rib portions defining as a whole a plurality of slits radially outwardly of said central point of said regenerative plates and radially and circumferentially spaced apart from one another, said plurality of slits of said regenerative plates defining a plurality of inner gas flow passageways in said heat exchanging unit in substantially perpendicular relationship to said first and second flat surfaces of said regenerative plates to allow said refrigerant gas to flow therethrough to effect a heat exchange between said regenerative plates and said refrigerant gas therethrough while said refrigerant gas is passing through said first and second ports of said gas casing.