OPM BWT PERMAQ® Pico Rev. 2.0 EN
Devices and components | 3
EN
9
3 Devices and components
3.1 Description of process
Semi-permeable RO modules separate the raw water flow, which is supplied under pressure,
into low-salt purified water (permeate) and waste water (concentrate), which is enriched with
ions. The percentage ratio between the “permeate quantity produced” and the “amount of
raw water required” is expressed as the permeate yield (WCF). The higher the yield, the lower
the waste water. Typical yields for current reverse osmosis devices are approximately 80%.
Alongside the level of efficiency, permeate conductivity is another quality indicator for reverse
osmosis devices. The conductivity provides information about the rate of dissolved salts in the
permeate. This value is mainly determined by the salt retention rate of the RO module used
and the feed water quality.
The operation of the BWT PERMAQ® Pico devices is controlled by a programme and the
devices require raw water that has been softened or conditioned with antiscalant (AS) to
achieve the optimum yield and a longer service life for the RO modules. They can be used any-
where that purified water quality and a production output of 180–2800
l/h is required.
Unlike conventional water throughput systems, BWT PERMAQ® Pico devices feature a full-fit
design with a minimal dead volume. This water throughput system more or less rules out any
contamination.
Concentrate
Permeate
Raw water
Fig.
1: Conventional water throughput system
Raw water
Permeate
Concentrate
Fig.
2: Full-fit water throughout system
The BWT PERMAQ® Pico devices can be used in both online and offline mode. This means that
the permeate produced is either stored in a permeate tank and conveyed to the consumer
with a booster pump (offline) or conveyed to the consumer via a pressurized tank without a
booster pump (online).
3.2 Description of process for the BWT PERMAQ® Pico Vario
The online variant BWT PERMAQ® Pico Vario focuses on maximum hygiene and variable output
adjustment. The device can be controlled both digitally and through pressure points (for in-
formation about setting, see the chapter
Setting pressure points (BWT PERMAQ
34]). Thanks to the use of a frequency-controlled high-pressure pump, the permeate
flow can be modulated and the permeate pressure can be maintained at an almost constant
level even when consumption fluctuates. Consumers can be directly connected to the reverse
osmosis device without using a conventional membrane pressure vessel as a permeate buffer.
