Analysis of tube bank heat transfer in downward directed foam flow

Apparatus with the foam flow are suitable to use in different technologies like heat exchangers, food industry, chemical and oil processing industry. Statically stable liquid foam was used in technological systems until now rather seldom. Nevertheless the usage of this type of foam as heat transfer agent in foam equipment has a number of advantages in comparison with one phase liquid equipment: small quantity of liquid is required, heat transfer rate is rather high, mass of equipment is much smaller, energy consumption for foam delivery into heat transfer zone is lower. The paper analyzes the peculiarities of heat transfer from the distributed in staggered order and perpendicular to foam flow in a channel of rectangular cross section tube bundle to the foam flow. The dependence of mean gas velocity and volumetric void fraction of foam flow on heat transfer in downward foam flow was estimated. Significant difference of heat transfer intensity from front and back tubes of tube row in laminar foam flow was noticed. The dependence of heat transfer on flow velocity and volumetric void fraction of foam was confirmed and estimated by criterion equations.