In the past, the only solution has been to limit furnace energy input to maintain low temperature at the baghouse and DEC draw. However, this low furnace input naturally lessens the likelihood of achieving more melts per day and meeting increased production goals. The DEC cooling strategy has even more drawbacks. Water sprays were mentioned as a means to help cool off DEC gas flow. Water cooling sprays introduce moisture into the gas flow.
Moisture causes secondary dust cakes on the filter to assume a sticky quality.
The cakes then do not release properly. Once the APC draft is reduced, power consumption increases because fans work harder to compensate for the increased resistance to gas flow through the APC system. Additionally, water in the gas stream creates the potential for hydrolysis of the polyester media, which weakens the material and results in failure. By minimizing the baghouse as a limiting factor in determining optimum furnace operation, the furnace operator can reach the goal of more melts and increased production. Scanning electron micrograph of a PTFE membrane is shown.