Multi-tube heat exchangers developed for hygienic/sanitary product to product heat recovery applications in the food, dairy and beverage industry. The fluids may also contain limited quantities of pulp and/or fibres.
XLG®MD Regenerative Multitube heat exchangers are manufactured entirely from stainless steel and consist of a bundle of corrugated tubes mounted within a corrugated outer tube (which forms the outer shell).
The sterile fluid flows through the interior of the tubes forming the tube bundle and the raw (not-sterile) fluid outside the inner tubes, through the shell.
All product wetted surfaces, including the welds, have a surface roughness Ra < 0.8 µm and are therefore able to process food products under the normal hygiene regulations. Such processes include pasteurisation, high temperature sterilisation, thermal treatment for aseptic packaging etc.
Both fluids (sterile and not-sterile) are completely isolated from each other, heat transfer taking place across the inner tube walls. Leakage of the service fluid to atmosphere is prevented by a pair of elastomeric O ring seals at each end of the tube. If hygiene and process conditions require it steam packing can be provided between the O ring seals at both ends of the units