This paper is concerned with heat transfer by plate spacers in plate-f
in heat exchangers. The spacers are considered as fins attached to the
plates and are exposed to certain boundary conditions. The thermal re
sistances at the contact surfaces between the plates and the fins are
assumed to be different from one another. Based on this model, equatio
ns for heat fluxes at contact surfaces are derived. Calculations from
these equations reveal a considerable influence of the thermal resista
nces at the contact surfaces on the heat transfer.