MICRODYN CAPILLARY MODULES | USER MANUAL
MANN+HUMMEL Water & Fluid Solutions | REVISION DATE: 09/09/2021
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5.3
OPERATION PROCESSES
5.3.1
Open Loop Operation
An open loop design is commonly used for batch processes, where a highly concentrated retentate is desirable. In an open loop
design, the retentate is sent back to the feed tank for further concentrating. A continuous operation is possible with an open loop
by continuously sending raw feed to the system and with concentrate bleeding.
Circulation Pump
Concentrate
Permeate
PI
PI
TI
PT
PBP
Device
Feed
SEPRODYN
®
Module
PI
FT
5.3.2
Closed Loop Operation
In a closed loop operation, the concentrate stream is sent back to the circulation pump ahead of the module. The advantage with
this design is that the circulation pumping pressure is reduced. The feed pump is what supplies the system pressure. Overall, the
pumping volume only includes the filtration flow rate and the bleed concentrate. The concentration of the concentrate is based on
the mixing ratio of feed and bleed flow. It is important to keep the periodic back pulse (PBP) valve wide open to bleed the high
amount of back pulsing water and to protect the feed side for a pressure increase.
Circulation Pump
Concentrate
Permeate
PI
PI
TI
PT
Feed
SEPRODYN
®
Module
Feed Pump
PBP
Tank
FI
PI
Compressed Air
Deaeration
Timer
PBP Bleed
Back
Pulse
Tank
Back
Pulse
Tank
Figure 7
. Simplified flow diagram for open loop operation.
Figure 8
. Simplified flow diagram for closed loop operation.
