Page 2305 - Flipbook_SolidDesignSoutheast2020
P. 2305
DENSE PHASE PROCESS
1. FILL 2. PRESSURIZATION
• Vessel at atmospheric pressure • Air is rapidly introduced into the ves-
• Inlet valve opens to allow product to sel through the fast-fill manifold
fill vessel • Transmitter starts to pressurize and
• Displaced air is vented down the product is fluidized above the porous
convey-line media
• Inlet valve is closed when desired • Product and air mix enters the dip
weight or level of product is reached tube and begins down the convey line
• The transmitter’s pressure raises to
BYPASS VALVE OPERATION the desired optimum operating pressure
The bypass valve is used to allow • The speed and efficiency of pressur-
displaced air to vent from the top of the ization eliminates the need for a costly,
transmitter, through the bypass line, and
down the convey line. This eliminates high maintenance discharge valve
the need for
an additional piping connection for a BYPASS VALVE OPERATION
vent line and valve. By using the convey The bypass valve remains closed to allow
line for venting, dusty air will be dis- the transmitter to quickly come up to
charged to an existing dust collector. optimum operating pressure.
3. CONVEY 4. DEPRESSURIZATION
• Air introduction is switched to stan- • As transmitter empties, the pressure
dard flow manifold starts to decay
• Transmitter pressure decays to near
• Product and air mix are discharged
clean line condition and air flow is
from the transmitter at the optimum turned off
operating pressure • Fast-fill air flow can be used to purge
the convey line if necessary
• Vessel reaches atmospheric condition
BYPASS VALVE OPERATION and is ready to start the next fill cycle
The bypass valve accurately controls
the product-to-air ratio as product is BYPASS VALVE OPERATION
discharged from the transmitter. When The bypass valve remains closed as
the convey pressure is reached, the pressure decays below the normal
bypass valve bleeds clean air from the operating pressure. Remaining air in
top of the vessel into the convey line. the vessel is vented down the convey
This brings the product-to-air ratio to the line eliminating the need for a vent line,
proper proportion for the selected con- vent valve and discharge valve. Valve
vey pressure. This requires only a simple controls are reset to allow for the next
regulator setting on the bypass valve fill cycle.
for field adjustment. The valve setting
is initially determined based on product
conveying characteristics and system
configuration (i.e., line size, number of
elbows, distance, etc.).
