The cleaning cycle is the most important part of the dust collector because it controls efficiency and media life. In order to clean a row of bags in a reverse pulse jet baghouse first the flow of filtered air must be momentarily stopped and then back flushed or “induce” air to knock the dust cake off the outside of the filter media. A venturi at the top of the bag/cage is used to accomplish such a task. The typical venturi is six inches long with a 1-3/4 “ diameter hole. While the reverse jet with venturi does provide some advantages when compared to other methods such as reverse air or mechanical shaker cleaning systems, the venturi creates undesired effects during the cleaning cycle. Not only is a vacuum created due to the close proximity of the blowpipe to the venturi, but also an area of significant flow is created directly after the venturi. This contrast in positive and negative flow is detrimental to the media and as a result, there is a large section at the top of the bag that is unusable for repetitive cleaning of the dust.
Advantages of cleaning without a venturi in baghouse collectors