Vapor degreasing heat energy

However, steam or hot oil may be preferred sources of heat energy for vapor degreasers and distillation systems because one can easily control the temperature to which the solvent (and parts) will be exposed. And there are no spark sources in these sources of heat energy Heaters usually operate only In the ON/OFF mode, so that proportional control is impossible. 

And the source of the heat is often hot oil passing through the inside of the firmed tubes. The oil is heated externally from the vapor degreaser to eliminate a source of ignition energy. 

In vapor degreasing with a single solvent, heat energy must be supplied to heat the liqirid solvent from ambient temperature to its normal boiling point, and then to change its phase to vapor. The former is known as sensible heat the latter is known as latent heat. It s thus with Class II and III cosolvent systems. The individual properties of each solvent affect the outcome heat balance. 

The rate of energy supply depends upon at least the thermodynamic properties of the solvent, and the size of the vapor zone as called for in the design of the degreaser. Some typical design values for the needed rate of energy supply to (1) heat the solvent in the boil siunp to its boiling point, and to then (2) rebuild the vapor zone are given in Tables 1.2 and 1.3 respectively. 

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