“Particulate and Condensable Removal” was the Subject of the Hot Topic Hour on April 25, 2013
Jim Griffin, Sales Manager at Donaldson Membranes, addressed “Particulate and Condensable Removal with Membrane Filters.” He pointed out that membrane filters do not rely on a cake buildup for efficiency. The very low emission levels required by the new regulations make it difficult to meet the requirements when the mechanism for capture (the cake) keeps varying. He also pointed out that the stitch seams are critical as are other seals and attachment methods. There are many instances where the basic material provides high efficiency but the dust does not pass through the media. McIlvaine reminded the audience that Jim at one time developed what he called the “square footer.” This is a few cfm filter which can be operated in parallel with the commercial installation. The outlet emissions of each can be compared using the same media. The difference in results is the dust passing around instead of through the media.
Andy Olds, Project Manager at Envitech, Inc, covered “WESP Technology for Particulate and Condensable Removal.” Envitech supplies scrubbers and wet precipitators to various industries. There are a number of units which are removing heavy metals. Andy pointed out that substantial mercury can be removed by cooling the gas stream to the point at which the mercury condenses.
Kevin Crosby, Technical Director at The Avogadro Group, says that the performance of the APC equipment is defined by the test method used. When condensables are included there is the potential for artifacts. With Method 2012 you may show high emissions but if you test with Method 39 the results are likely to be much better. With either method ammonia still causes artifacts.
Tom Anderson, Vice-President Pleated Products at TDC Filter Manufacturing, Inc., (Midwesco Filter Resources Company) explained that pleated filters are performing well and can achieve efficiencies comparable to a 18-20 oz polyester felt at 50 percent of the pressure loss. This creates an energy savings. A bigger savings is achieved because the pulse cycle need only be 25 percent as often. At one plant the total energy savings was $22,000. There was 1.3 million cu/ft of compressed air savings. At $0.01/ft there was a $13,000 saving in compressed air to supplement the $9,000 saving in fan horsepower.
Bios, Abstracts and Photos can be seen at: BIOS, ABSTRACTS, PHOTOS - 4-25-13.htm
The individual presentations are as follows: