Pulse Jet Air Intake Filter (펄스젯 필터) 원리
HOW THE PULSEJET FILTER WORKS
Filtering out the dust.
• As the dust-laden air enters the filter, fine particles are borne into the cartridge area. The air passes through the filter
media, depositing the dust on the outside of the filter. The filtered air continues up the inside of the cartridge into the
clean air plenum and then out of the filter housing. Cleaning the Filters
• Accumulated dust on the exterior of a filter is periodically
removed by directing a short pulse of compressed air down the inside of the cartridge. An aerodynamically designed
venturi at the top of each cartridge causes the pulse of compressed air to induce a flow of clean air into the
cartridge. A shock wave is set up that travels down the filter and hits a solid plate at the bottom. The shock wave
momentarily pressurizes the filter, stops the flow of dust-laden air into it and flexes the media; the effect is enhanced
by the plate at the bottom. The dust falls off, and drops to the open atmosphere.
• This instantaneous cleaning action proceeds row by row
while the flow of dust-laden air into the filter continues uninterrupted. Each row being cleaned is off-stream for
1/20th of a second (nominally); the entire media area of a pulsejet filter is in virtually continuous operation.
HOW THE PULSING AIR SYSTEMS OPERATES
Normally Closed Position.
The solenoid armature blocks passage of compressed air from the pilot valve. Air bleed passages
provide equal air pressure on the left and right sides of each diaphragm. Since more area is
exposed to air pressure on their left sides, the diaphragms are pushed to the right. Springs assist
in holding the diaphragms in their closed positions.
Pulsing position.
The solenoid armature lifts off of its seat when the coil is energized by a 50-millisecond
electrical pulse from the timer. The pressure balance across the small diaphragm is upset as air
escapes through the pilot valve, causing the small diaphragm to open against spring. This action
uncovers the large diaphragm vent, and a pressure imbalance develops across the large
diaphragm. Unequal air pressure opens the large diaphragm against spring, uncovering the
blowpipe. Air from the compressed air header passes through the blowpipe to clean the filters.
When the solenoid armature returns to its seat (after 50 millisecond electrical pulse), pressure
balance is restored through the air bleed passages, and both diaphragms are closed again by
spring and pressure forces.
