Aqua-Base ARUBA Premium Manuel Utilisateur page 10

AQUA-BASE
ARUBA Premium
Technical manual
1.3.6 Automatic pressure regulation
The pressure regulation in the membrane(s) of the
is accomplished by the Variable frequency drive which assures the high-pressure pump speed; The more
pressure needed, the higher the pump speed and vise-versa.
The pump speed is regulated according to the capacity of the machine
capacity)
so it'll always perform in accordance with the current feedwater conditions (salinity and
temperature).
The 3 elements that make this possible are the VFD (VS40), the flowmeter (Fi61) and the flow restriction (AJ49) in the reject
line of the membrane.
When the feedwater salinity increases and/or temperature drops, the membrane will allow less water to pass
through which results in less freshwater production. This is detected by the flowmeter. The control card
program will send the signal to the VFD, which will ramp up the pump speed. The increased pressure will
result in more freshwater production.
In the opposite case (feedwater salinity decreases and/or temperature rises) the pump will slow down in
order to protect the membrane of overproducing which is bad for the lifespan of the membrane.
NB: The pressure sensors in the machine will always prevent the VFD ramping up the pump speed if the pressure detected
approaches the maximum allowed in the system.
Slow-start
The other advantage of the VFD is, that it allows for a soft start / stop of
the HP pump. When the pump is started, it slowly ramps up from the full
stop to its operating speed. This reduces stress on all parts of the high-
pressure system (the valuable membranes, the pump itself, the piping
and fittings, etc....).
It also eliminates an electrical spike when starting the pump and thus puts
less strain on the power supply.
•
AQUABASE ARUBA Premium
models is fully automated. This
(the rated freshwater production
P40 – M40 HP pump & Motor
VS40 Variable Frequency drive
VE45 – ME46 Membrane
AJ49 Flow restriction
Fi61 Flowmeter
This simplified flowchart diagram, shows
these elements working together to
enable this process.
The full flowchart can be found in annex
A1
The Variable Frequency drive in the
electric box.
REV.H
P10/129