HEATING OF ELECTROSTATIC PRECIPITATOR HOPPERS, AN OVERVIEW OF THEORY AND APPLICATION.

Considerable energy waste and field maintenance problems have resulted in past electrostatic hopper heating applications. The author has three purposes to accomplish in this paper: (1) to analyze heating design specification criteria in an effort to evolve a minimum energy use specification; (2) provide a review and discussion of the various types of heating elements available; (3) make recommendations to eliminate common problems and mistakes that are made in the design and installation of the various hopper heating systems. Significant power savings can be effected by designing for ″dew point″ temperature maintenance rather than electrostatic precipitator gas temperatures. This can result in total power use savings of 50% over the older methods. More and thicker insulation is a natural recommendation in the face of expected energy cost increases. When properly designed and installed, any of the available hopper heating systems will give a good working heating system.