(113a) Evaluating the Heat Exchanger Technologies Available for Use In Refinery Pre-Heat Trains

Fouling behaviour is a crucial consideration in the selection and design of heat exchangers to be used in refinery pre-heat trains.

 We make the following observations regarding fouling associated with the heating of crude oil:

 1. The fouling rate decreases with increase in wall shear stress

2. The fouling rate increases with increase in wall temperature

3. Deposition on an existing deposit occurs more readily than deposition on a clean metal surface.

 We then use these observations to evaluate the following range of technologies:

 Use of the shell-side of exchangers with segmental baffles and with helical baffles.

Use of tube inserts (Turbotal^TM, Spirelf^TM, HiTran^TM and twisted tapes)

Exchangers having longitudinal flow on shell-side( Twisted Tube Bundles, Rod Baffles, Wire Mesh Baffles)

Compabloc^TM Exchangers