HygroMatik WL-ROL 160-1200 Series, Руководство пользователя

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Page 11
4. Function and structure
4.1 Mode of operation
General principle of reverse osmosis
Osmosis is a natural process, it is understood
as the one-sided diffusion of a liquid (here the
feed water) through a semi-permeable mem-
brane. A semi-permeable membrane is only
permeable for certain substances..
As the liquid moves through a semi-permea-
ble membrane, the pressure on the side with
the lower concentration decreases and at the
same time the pressure of the more concen-
trated solution increases until a balance is
reached, stopping the water flow. Pressure
difference between the two liquids is called
"osmotic pressure".
Reverse osmosis, on the other hand, is a
technical process in which the natural pro-
cess is reversed. It involves applying a pres-
sure higher than the osmotic pressure to the
concentrated liquid so that the water flows in
the opposite direction through the semi-per-
meable membrane and thus separates the
salts solved in the water.
Using this principle, water can be demineral-
ized for drinking water as well as for process
and industrial applications.
4.2 Influencing factors
The performance of the reverse osmosis
membrane depends strongly on the following
parameters:
Water inlet pressure at the membrane:
By lowering the working pressure, a reduc-
tion in permeate production can be achieved.
By increasing the working pressure, an
increase in permeate production is also
achieved.
The pump pressure can be changed by turn-
ing the screw on the pump (see chapter 8.4).
Be careful not to exceed the maximum pump
pressure!
Salt content of the feed water:
The higher the salt content, the faster the
membrane wear.
Temperature of the feed water:
The WL-ROL unit is set up for a feed water
temperature of 15°C. Any difference from this
temperature will affect the production quan-
tity and the quality of the permeate.
The following table shows the variation of the
permeate production quantity by 3% per dif-
fering 1°C.
The colder the feed water, the lower the per-
meate production and the better/lower the
conductivity.
The warmer the feed water, the higher the
production quantity, but the lower the perme-
ate quality.
Temperature 15 °C + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8
Correction factor 1 1,03 1,06 1,09 1,12 1,15 1,18 1,21 1,25
Temperature 15 °C - 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8
Correction factor 1 0,96 0,92 0,88 0,84 0,8 0,77 0,74 0,7