itEAT f"KASSFER intptnwm~ertt (a$ #W;JI rnm$er cwne in for considetabfc attention. Hickman (USA, SWD/27) developed an explanation of the low ex~r~rn~nta~ esaporati~n coeK-tcicnts by supposed heat starvation of the evaporated surface. This subject is reviewed and further data supplied in Hickman's paper ~~~sfi~jr!f?riu~~, f(l), t3). Etliott and OukFer (USA, SWDi2t) dealt with two phase finw 2nd set up a theoretic& model for a vertical falling film evaporator. Comparison with cxperimcnr wve agreement to within t.8-5.841-i. Two-phase pressure drop and cntrainmcnt were measured in experimental equipment and the large disturbances due to slight surface roughness and scale emphasized. Carnavos (USA, SWD,Il-I) dcicribcd the "Double Flute" develop& by the Gcncrz4 Electric Corp. to maintain thin films during evaporation and condensation. Condensin% heat transfer coeffcients 41 to 7 times those in smooth tubes of equal outside area were obtained, and afso much increased evaporation coetficients were iound. Inner and outer flutes are obtained in one ~nafacturjn~ opention, and Carnavos thinks that for large-scrtte production these lubes will not be expensive Several pitot plants using such tubes gave very satisfactory results and further improvements arc possible when tube materiafs of fow cost, high conductivity and r&stance to corrosion become nvailab?e. Droptt& cclnrierts&io~l expcrimcnts were reported by Erb and Thdcn (Frankfin Inst., USA, SWD/SI). Though Camavos claims his double fluted tubes superior, high heat transfer condensation coetlicicnts were obtainLed by dropwise condensation on tubes either with thin poiymcr coating or noble met4 coats. Extremely thin coatings are an economic necessity and experiments with a siher layer under a very thin SoId or paiIadium coat are reported. Condensation coefficients 5%SZP,: higher thsn on uncoated tubes promise smalier and perhaps cheaper evaporators. Chernotubov et al. {USSR, SWD'fZt examined various means to intensify heat transfer, such as condensation of steam by bubbling it through a suspension of a tvater-rep&ant liquid, as well as more conventional means, such as sificone-coated condenser surfaces. thorough deaeration, and high vehaeities. Heat transfer coefitients of 1OO,OOO-180,000 kcal/m' hr "C for steam and 30,000 kcal/mZ hr "C for brine were obtained in extreme cas42s. Maltsev, Yufin et al. (USSR, SWDj66) reported on a liquid-liquid ktt exchanger where jets of a diphenyi-diphenyl oxide mixture are sprayed into water, Exprimental f OL LWulinafiun, 1 (1966) 10t-106