Pulverized coal-fired utility boiler with a baghouse in parallel to an existing mechanical collector/electrostatic precipitator system. Baghouse effluent used to reheat flue gas leaving SO2 scrubber.
The pulse jet baghouse was designed at an A/C ratio of 3.8 cfm/ft2 (gross) 5.0 cfm/ft2 (net) with on-line or off-line cleaning capabilities. Design gas flow of 45,000 acfm at 400ºF. Conventional woven glass bags quickly blinded due to fineness of dust (25% < 3.3 µ) and the formation of sulfate compounds in the weave of the fabric. Bag life was < 9 months. The pressure drop was 10" w.g. at 75% of design airflow. TEFLON® felt and fiberglass felt bags were tested and found to blind quickly also.
GORE® membrane/Teflon® B fiberglass fabric filter bags (16.8 oz fabric) were installed. Pulse pressure was reduced to 70 psig; diffusers were removed.
Design airflow achieved. Bags cleaned on demand at 6" w.g. SO2 scrubber costs reduced by over $12,000/month (less reagent used and less fuel for reheat). Installed second set of GORE® membrane filter bags. During annual outages, the first and second set of GORE® membrane filter bags were replaced after 20 months and 36 months respectively, even though the bags had not failed.
Not for use in food, drug, cosmetic or medical device manufacturing, processing, or packaging operations