19
Kice Industries, Inc.
012420 / FLT-M02-0004
Early day fi lters were simply dust chambers with cloth bags that had to be cleaned manually by shaking
or rapping the bags to remove the dust. Mechanical shakers were devised to do the same thing, but
compressed air jets provided a more positive cleaning eff ect. It is necessary to operate the cleaning
jets at approximately 100 psig of pressure in order to induce the supplementary air volume (through a
venturi) needed to provide adequate bag cleaning. The compressed air needs to be clean, dry, and oil
free.
The compressed air is piped to the air tank mounted on the side of the fi lter, next to the clean air
chamber. The Kice Venturi-Jet blast valves are located between the air tank and the manifold lines that
run inside the clean air chamber above the fi lter bags. Each bag has a venturi mounted to the tube
sheet above the open end of the bag. The air tank is fi lled with compressed air to a pressure of
80-100 psig, at which time an electric signal is sent to activate a solenoid on one of the Kice Venturi-Jet
blast valves. The valve opens and quickly discharges the tank of pressurized air through the manifold
and into the venturis located above each of the fi lter bags in that row. This pulse of air causes the dust
particles collected externally on the fi lter media to be dislodged and fall into the hopper. After an
adjustable amount of time, the controller cycles to the next Kice Venturi-Jet blast valve in sequence
and activates its solenoid, which releases air to clean the next row of fi lter bags.
The complete Kice Venturi-Jet fi lter control circuit is shown on the schematic located on page 21. The
Kice Venturi-Jet blast valves (see Figure 12) are mounted between the air tank and the cleaning
manifolds. The Kice Venturi-Jet blast valve is a 2 way, normally closed, diaphragm type valve utilizing a
spring and air pressure above the diaphragm to cause the diaphragm to seal. When the pressurized air
above the diaphragm is exhausted to the atmosphere through the solenoid valve, the diaphragm lifts
to the open position. The air in the tank is then discharged into the cleaning manifold in a fraction of a
second (the pulse duration is adjustable by the “on-time” setting in the control panel). When the
solenoid valve closes the pressure equalizes, allowing the diaphragm to close. As this high pressure jet
of air is fi red through an orifi ce in the manifold and into the venturi located above the fi lter bag, the jet
of high-pressure air induces additional air from the clean air chamber to fl ow into the bag. This creates
a shock eff ect that dislodges dust and other foreign material that is caked on the outside of the fi lter
bag (see Figure 13).
8. Filter Operation & Start-Up Procedure
Figure 12
Figure 13
Kice Venturi-Jet Blast Valve
Discharged Air Creates
Shock Eff ect