Pulse Jet Baghouse Dust Collectors
The pulse jet baghouse was developed by MikroPul in the 1950's and was designed to allow more air per given area of baghouse, which meant higher air-to-cloth ratios. A pulse jet system generally operates at 5-6:1 air-to-cloth ratio. This requires smaller housing, making it less expensive to construct. Filter bags hang vertically inside the unit and are firmly held in place by clamps, snapbands or hold-downs and the bag bottoms are enclosed. In this type of system, the bags are supported internally by wire cages.
Dust-laden gas enters the system through the inlet and is filtered through the bag, depositing dust on the outside surface of the bag. During cleaning, the dust is removed by a blast of compressed air injected into the top of the opening of the filter bags. The air is supplied from a blowpipe which feeds into venturies located above the filter bag. The blast of high pressure air stops the normal flow of air though the filter. A 85 - 100 PSI of air is recommended per blast.
The air blast creates a shock wave that causes the bag to flex as the air wave travels down the length of the filter bag. As the bag flexes, the cake fractures and particulate is released into the hopper below. In most baghouse designs, a venturi seated at the top of each bag is used to increase air velocity in order to create a large enough pulse to travel down and back up the filter bag.