Abstract: An end manifold (2) for a concentric tube heat exchanger, the end manifold being especially suitable for treatment of viscous fluids. The end manifold has an obliquely oriented shoulder (38) which serves to direct the viscous fluid into an outlet port (30) so as to avoid stagnant regions of the viscous fluid which would be otherwise subjected to overheating. The same manifold can be used at the inlet end as well as for cooling purposes and allows for more effective cleaning when a cleaning fluid is circulated therethrough.

Abstract: A heat exchanger for fluids comprising a plurality of coaxially arranged tubes of thermally conductive material, the tubes being spaced apart radially by end manifolds to form annular fluid flow passages, characterized in that at least one of the manifolds includes sealing surfaces which bear against and form seals with the inside surfaces of the ends of the tubes. The arrangement is such that sealing contact is made with the inside end surfaces of the tubes and thereby enabling the manifolds to be of much lighter weight and thus less expensive to cast.