The HTD Heat Trace hopper heating systems, including the HB module and Type G blanket are the solution to HOPPER PLUGGAGE due to condensation in flyash collection hoppers. Condensation occurs in the flyash collection hoppers when the hot flue gases are allowed to cool to temperatures below dew point. When condensation forms in the collection hoppers, the dry, normally smooth−flowing flyash quickly turns into a thick, paste-like, immobile mud. The hopper throat area rapidly becomes blocked and evacuation of the flyash from the hopper becomes impossible. Depending upon the style of Air Pollution Control Equipment being used, continued build-up of flyash within collection hoppers that are “blocked” can result in :
- Shorting of high voltage buss sections
- Hopper fires
- Structural damage to, or actual destruction of the collection unit (Precipitator, Baghouse etc)
- The necessity to use plant personnel to manually clean out the collection hoppers.
The HB Heating Module and Type G Blanket Hopper Heating Systems are custom designed to provide low watt-density, uniform heating over the lower areas of the hopper. Thermal sizing is based upon maintaining a temperature above the dew point of the incoming flue gases such that condensation cannot occur. The elimination of condensation ensures that the Flyash (or dust) being collected will remain in a dry, free-flowing condition such that the hoppers do not plug.