- The emissions from the boiler consist of dust and gases that are not completely burned. These can be ignited by sparks coming from the boiler. The loading of these pollutants can vary widely. Gases may continue burning with a flame, and, sparks may be in the process gas stream.
- If we install a spark arrestor, such as a QUENCHER, before the dust collector, it will cause the gas pollutants to burn producing heat, carbon dioxide and some small fraction of water vapor. The QUENCHER will also prevent any sparks from entering the dust collector as the hot ciders will be immediately cooled to the gas temperature, as the air goes from laminar flow to turbulent flow and back to laminar flow. We now have cooled dust and ash entering the dust collector. The pulsing action of the cleaning system will fan any red-hot cinders if they are present. For reasons beyond the scope of this report, the dust cake will be dense and subject to ignition. Fortunately, conditions must be in a narrow LEL/UEL range to start a fire. With conventional pulse cleaning systems only a fraction of the filter cake on the bags is functional and the rest of the bags are plugged.
- We would modify the cleaning system with modifications that would enable the full surface of the filter media to be active. This would mean that the inventory of flammable dust would be reduced by over 95% so there would be no combustible dust between cleaning pulses. Surprisingly, the cleaning frequency would also be reduced. To accomplish this, we would need information regarding the design of the existing dust collector.
When completed
this would be the best design, and, barring unforeseen circumstances such as
power failures at inopportune times, the system should perform flawlessly for
years. The only risk is that the filter bags
could be attacked chemically.
More information on... retrofitting existing dust collectors
No comments:
Post a Comment