A typical application for surface heating is Hoppers. Reliable and effective hopper heating systems play an important role in the removal of flyash from precipitators and baghouse hoppers. The hopper heater must be designed for preheating the hopper to prevent moisture condensation from collecting in the hopper during startup conditions in addition to maintaining the hopper (and flyash) above the flue gas acid dewpoint during normal operating conditions. During the last decade many designs and operating procedures have been tried to minimize or eliminate hopper pluggage caused by compaction, agglomeration and solidification. Many of the earlier designs were based on solving the compaction problem only by means of poke tubes and mechanical vibrators. Fluidizing systems on the other hand to require significant maintenance. Hopper heating was recognized as the most practical method to prevent agglomeration and solidification. The heater was specifically designed to provide a reliable source of hopper heating.
