Heat exchanger has drum contg. tubes in tube plates - and semi-toroidal thermal expansion element fixed to drum and outside of cold plate

摘要

The heat exchanger comprises a number of straight parallel tubes whose respective ends are secured in tube plates. carried in a drum which fits around the tubes with little clearance. A flexible element is provided to absorb the differential expansion between tubes and drum. This element has one side secured to a tube plate and the other side to the drum and is arranged outside the plane of this plate. The element is pref. of semi-toroidal form having its inner and outer rims extending axially relative to the centre line of the heat exchanger. Used as heat exchanger with tubes, e.g. for transferring heat from very high-temperature gas to high-pressure water. The arrangement minimises or eliminates the bending moment in the outer region of the (cold) tube plate which occurs in a heat exchanger of existing design having a flexible element in the form of a bellows arranged at a larger dia. i.e. in the drum wall. It thus permites the use of a thinner tube plate which minimises the thermal stresses occurring in this plate.