The condensation of steam containing low concentrations of trimethylamine

This report describes the condensation of steam, on a horizontal tube, when the steam contains a low concentration of trimethylamine. Previous tests in this programme have studied the addition of ammonia and methylamine; all of these tests were conducted at similar or identical operating conditions. The most significant difference in properties of these ammonia series additives is the magnitude of the surface tension variation that develops when their mass fractions are increased. All of the vapour additives generate Marangoni instabilities in the condensate film; the type of instability depends on the additive but at very low additive concentrations the rates of heat transfer through the film will be higher than those found when pure steam condenses.