Variations of Fabric Filters
Fabric filters are also known as baghouse and their major role is to clean air or produced gases in the certain processes by the action of trapping the particulate matter in the air or the gas and allowing the clear gas to pass through the fabric. Filtration is the technique employed in the this particular technology of air pollution control since the fabric filters the air or gases leaving the particles on the fabric and the air or gas passing through it. This technique of air and gas pollution control is mostly applied in the type of industries that emit fumes and smoke which could contain harmful particulate matter. The industrial requirements of the fabric filters will vary due to a number of factors such the quantity of the fumes and smoke generated by a particular industry hence whereas some industries will require tiny and simple fabric filters, others might require bulky fabric filters. Generally, a typical house bag consist of an inlet through which the dirty gas gets into the system for filtration and an outlet through which the filtered gas or air exits through, a tube that attaches to the fabric filters and an opening at the bottom which drops the collected dirt or particles. The manner in which the fabric filters are cleaned or cleared of the particles is the basis of classification of the house bags. This classification of the fabric filters according to the dirt removal mechanism from the surface of the filter fabric yield three types of fabric filters namely, reverse air housebags, shaker housebags, and pulse jet housebags. When it comes to the reverse air technique of fabric filters, the incoming dirty air is allowed in through an inlet and out from the inside of the housebags through an outlet hence the dirt collects on the inside of the housebags and the housebags are typically suspended on an adjustable frame at the top. This technique of air pollution control is referred to as reverse air because the dirt is removed by blowing the cleaning air in the reverse direction forcing the housebags to collapse momentarily, and this forces the collected dirt to crack and fall off from the surface of the housebag. Before this cleaning cycle is begun, the filtration process is first stopped vin the housebags to be cleaned and after the cleaning process the reverse air flow is stopped and the system gets back to normal. For the shaker type of housebags, the dirt is removed from the fabric filter by shaking it off and filtration process is first paused to allow for the shaking to remove the collected dirt hence it’s a mechanical method. Pulse durations of compressed air are utilized in the pulse jet housebags hence the name.