Plate heat exchanger and edge seal

Claim 2

A plate heat exchanger of the type comprising plates sealingly attached to each other in pairs, between which plate pairs in an assembled state of the heat exchanger gaskets extend in grooves embossed in the plates, characterized in that the plates attached in pairs to each other are connected to each other in edge areas by a sealing folding, which extends inward between the individual plates and inward between the embossings facing toward each other in the two plates and forming said grooves.

Claim 3

A plate heat exchanger as defined in claim 1, characterized in that the folding consists of a single inward folding made in one plate and of a folding made in the second plate in parallel with said inward folding and extending in the same direction and of a subsequent folding about the free edge of said inward folding.

Claim 4

A plate-type heat exchanger, comprising: a plurality of plates having respective outer perimetrical margins, these plates being arranged in a series, in confronting relation, in pairs; means defining a perimetrical groove in each plate generally ringing the outer perimetrical margin thereof, each such groove opening in an axial direction relative to said series and, on each pair of plates, being externally concave and having internally convex sides in relation to the plates of that pair and participating in providing a space within each pair of plates, axially between the respective grooves on the two plates of that pair; from pair to adjoining pair among said pairs of plates in said series, the grooves being of corresponding placement so as to provide pairs of corresponding, confronting grooves; a sealing gasket received in each such pair of corresponding, confronting grooves for sealing between the respective adjoining pairs of plates; and means sealingly attaching the two plates of each said pair to one another, including the two plates of each pair being marginally folded over in a doubling sense, to such an extent that edge portions of the two plates lie between, and axially fill said space between and, as a set, are engaged between the respective two groove convex internal sides.

Claim 5

A plate-type heat exchanger, comprising: a plurality of plates having respective outer perimetrical margins, these plates being arranged in a series, in confronting relation, in pairs; means defining a perimetrical groove in each plate generally ringing the outer perimetrical margin thereof, each such groove opening in an axial direction relative to said series and, on each pair of plates, being externally concave and having internally convex sides in relation to the plates of that pair and participating in providing a space within each pair of plates, axially between the respective grooves on the two plates of that pair; from pair to adjoining pair among said pairs of plates in said series, the grooves being of corresponding placement so as to provide pairs of corresponding, confronting grooves; a sealing gasket received in each such pair of corresponding, confronting grooves for sealing between the respective adjoining pairs of plates; and means sealingly attaching the two plates of each said pair to one another, including the two plates of each pair being marginally folded over in a doubling sense, to such an extent that edge portions of the two plates lie between, and axially fill said space between and, as a set, are engaged between the respective two groove convex internal sides.

Claim 6

The plate-type heat exchanger of claim 3, wherein: within each pair of plates, one is marginally folded in a doubling sense but once, so that its edge portion points medially inwards of the heat exchanger and is axially spaced from both said respective two groove convex internal sides, leaving two gaps, and the other is marginally folded in a doubling sense once so that it extends medially inwards through and fills one of these gaps, and a second time so that it curls around the edge portion of the respective said one plate and extends laterally outwards through and fills the other of these gaps.