Published online by Cambridge University Press: 01 June 2009
The operation of equipment for reducing the amounts of volatile taints in liquids by the use of open or generated steam is explained and analysed. From consideration of material balances for each system and the equilibrium characteristics of the volatile substances, formulae and graphical methods are derived and used to show the degree of taint removal which can be attained by the steam. The methods and charts are used to show the performance of Tandem and Triple Vacreators. The methods presented in the paper can be used for any volatile solute but particular reference is made to two substances having equilibrium constants of 17 and 1·4 because these represent a range of volatilities of particular interest and are approximate values for diacetyl and acetoin which can be used as reference substances.
The effectiveness of any system is shown to depend on the value of a stripping factor which is equal to the product of the equilibrium constant and the pounds of deodorizing steam per lb. of liquid (i.e. F = mV/L). The efficiency of methods where the liquid is contacted several times with fresh steam is shown to be much greater than for single contact. The gain in efficiency for each stage becomes less pronounced with increasing contacts and the maximum efficiency is shown to be limited even for an infinite number of contacts.