Reversal chamber for a tube matrix of a heat exchanger

A heat exchanger comprising first and second ducts one for supply of compressed air to be heated and the other for discharge of heated compressed air, a tube matrix forming first and second branches with inner and outer tube ends, the inner tube ends of said first and second branches being respectively connected to said first and second ducts for conveying compressed air from said one duct to said other duct, said branches of the tube matrix projecting transversely to a flow of hot gases therearound which heats the compressed air conveyed therein, and a plate heat exchanger exposed to the flow of hot gases, said plate heat exchanger including a row of juxtaposed spaced pairs of plates defining gaps therebetween for flow of the hot gases through said gaps, each of said spaced pairs of plates cooperatively defining therebetween a reverse flow chamber means for the compressed air, said pairs of plates being respectively connected to said outer ends of said first and second branches of said tube matrix for heating said compressed air in said flow chamber means by the hot gases flowing through said gaps during reversal of flow of said compressed air from said first to said second branch of said tube matrix.