Volume 17, Issue 2 (March 1989)
Solving Air Pollution by Reducing Emission Losses from Solvent Vapor Cleaning Systems
This paper discusses design of vapor cleaning systems and how proper design can reduce solvent losses from these units. It addresses such items as proper freeboard, work openings, heat balance, compartment dimensions, covers, operational controls, and heating elements. Solvent loss mechanisms are discussed in detail, such as diffusional losses, solvent drag-out, leakage, and poor maintenance.
One section is devoted to choosing the proper solvent for a cleaning system and how the physical characteristics of solvents can contribute to high losses if the solvent is improperly chosen.
Solvent emission reduction devices, such as hoods, transport systems, freeboard chillers, containment of sprays, hot vapor drying, carbon adsorbers, and solvent cool-down coils, are detailed in regard to their effectiveness. The final section is dedicated to process control of the cleaning system through the use of computers.