

Principle:
The pulse-jet regeneration system uses an air ejector located downstream of filtration elements, as shown in the sketch above. When a short pulse of compressed air jet is directed into this ejector it mixes with large amount of clean air downstream of filtration elements, and resulting mixture is pushed in reverse through filtration fabric. This rapid air flow results in fabric flexing, causing release of the dust cake from the fabric surface. The broken dust cake falls into the dust hopper.
Advantages:


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Very intensive regeneration action caused by dynamic forces in the dust cake, as well as high reverse air flow velocity, which is as much as 2 to 5 times higher as compared to plain reversed ambient air flow regeneration described below
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This principle is adaptable to both positive, as well as negative pressure dust control systems |
Disadvantages:


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Cost of providing compressed air at a pressure of 0.5 to 0.7 Mpa
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Danger of freeze up of compressed air pipes in areas of subfreezing temperatures
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Shorter life of filtration fabric caused by high fabric stress during intensive dynamic pulse
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Slightly lower dust control efficiency caused by dust particles penetrating filtration fabric during the air pulse
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Settling of broken dust cake into the hopper is incomplete for very short duration of the air pulse of 0.1 to 0.3 seconds. Often this setback is resolved by cleaning part of the filter, which must be off line.
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Initial and operating cost of the pulse-jet filters is higher as compared to reverse atmospheric air flow regeneration |
Recommended Application of Pulse-Jet Filters:

Best performance can be achieved when applied to control of very fine and sticky particulates, as for example emissions from glass melting furnaces, laser and flame metal cutting, welding, dip galvanizing, etc. Also wherever the filter operates under positive pressure, like in controlling dust emissions from storage tanks filled with pneumatic transportation system.
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