Heat exchanger

DETAILED DESCRIPTION The claims defining the invention are as follows: 1.
A heat exchanger for fluids comprising a plurality of separate coaxially arranged tubes of thermally conductive material, the tubes being spaced apart radially by and removably clamped between end manifolds to form separate annular fluid flow passages, characterised in that at least one of the manifolds includes cylindrical surface portions extending into the ends of said tubes and resilient sealing elements on said surfaces and which bear against and form seals with the inside surfaces of the ends of the tubes, said manifold also including shoulders against which the ends of the tubes bear.
2.
A heat exchanger as caimed in claim 1, wherein the manifolds at either end of the heat exchanger are identical and each has respective sealing elements for each tube.
3.
A heat exchanger as claimed in claim 2, wherein the manifolds are generally conical in shape and the sealing elements comprise progressively larger diameter O-rings recessed into sealing surfaces spaced axially along the manifold for cooperating with the interior surfaces of progressively larger diameter tubes of the exchanger.
4.
A heat exchanger as claimed in claim 2, wherein each manifold includes a central partition which divides the interior of the manifold into first and second chambers and first and second ports which communicate with the first and second chambers respectively, said ports being located at the wider end of the manifold.
5.
A heat exchanger as claimed in claim 4, wherein each manifold includes first openings which interconnect the first chamber with alternate ones of said annular fluid flow passages and second openings which interconnect the second chambers with intermediate ones of said annular fluid flow passages.
6.
A heat exchanger as claimed in claim 5, wherein each manifold is formed with a plurality of said shoulders against which the ends of respective tubes bear, and, located adjacent to each shoulder, a pair of grooves which receive respective O-rings which bear against the inner surfaces of the tubes