AEC HE Mass Flow Series Drying hoppers - Manual (Page 20)

HE
• CHE • BCHE Mass Flow Series Drying Hoppers
Page 19
CHE and BCHE Drying Hoppers
In systems where one dehumidifying dryer supplies air to several drying hoppers rigid manifold
lines should be installed for both air delivery and return. The manifold lines should include
butterfly valves leading to each drying hopper to throttle the air flow to the drying hopper
requirements. Air flow can be measured using a pitot tube and an instrument such as a hot wire
anemometer. The measurement should be taken in the line on the downstream side of the
butterfly valve, with all drying hoppers full of material and on line. A by-pass valve is also used
in the air supply line after the last drying hopper, to bleed any excess air flow to the return air
line. Do not bleed this air to atmosphere. Butterfly valves can be installed in the return line to be
able to turn a drying hopper off line. It is very important to have the air supply by-pass valve
installed on the last drying hopper if you choose to turn one drying hopper off line.
Figure 7
Typical Multiple Hopper Drying Hose Installation
Throttle/shutoff valve
Process
return
air
Process
supply
air
Bypass
valve