A. Introduction

Cylindrical shell heat exchangers may be supported in either the horizontal or vertical planes. Vertical thermosyphon reboilers, which are generally relatively small, typically no larger than 1 m. diameter and 3 m. long, may be hung from the distillation columns provided they are located close to the column. They are generally supported near to the top tubesheet and with two brackets on either sides of a vessel diameter. If their location and size do not permit this then separate steelwork may be required.

Vertical condenser/subcoolers generally need to be arranged vertically in order to carry out both condensing and then subcooling. As they tend to be larger than the above reboilers they are usually supported on four brackets, again near the top tubesheet to minimize expansion difficulties with the large connections on the tubeside. The brackets are located on two vessel diameters 90° apart.

In other cases the heat exchangers are placed in the horizontal plane and in these cases are supported using two saddles. This arrangement permits the support of exchangers which are of larger diameter and length, than those above, or they may be of substantial overall weight in view of the fact that they are required to operate at high pressure, requiring a thick walled shell and heavy flanges.

Section 419H, Section 420H and Section 423J(g) of the Handbook discuss the requirements of various codes for the design of heat exchanger supports. It will be noted that the most comprehensive approach is provided by the British Standard. British Standards Institution (1994), the analytical basis of which is discussed in Section 404C. Further information pertaining to the analysis of local loading is also provided in the Wickman et al., (1979); this latter is often employed by designers who use American Society of Mechanical Engineers (1998).