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: The specification discloses a heat exchanger of particular construction and methods of using same, the exchanger having pairs of sealing elements through which a circulating fluid is passed. The circulating fluid can be used for leak detection, cooling, or sterilization. The exchanger has a plurality of coaxially arranged tubes of thermally conductive material, the tubes being spaced apart radially by a pair of end manifolds to form annular fluid flow passages at least one of the manifolds having first and second sealing elements for forming seals between the manifold and the ends of the tubes, circumferential fluid passages being defined between the first and second sealing elements, circulating fluid inlet means for admitting a circulating fluid at first locations in the passages, and circulating fluid outlet means for discharge of said circulating fluid at second locations in said passages, the first and second locations being circumferentially spaced for each passage.