Quincy QSV 2200, Инструкция по эксплуатации

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Section V - Options
Quincy Vacuum Pump-QSV Series 75
2. Total dissolved solids (TDS) and conductivity
The conductivity is expressed in S/cm, the TDS in ppm.
Both parameters are related with each other. The conductivity is convenient for quick monitoring of general
water quality, but the TDS is required for calculating the RSI. If only one of both parameters is measured, an
estimation can be obtained by using a theoretical conversion factor (0.67):
TDS = conductivity x 0.67
3. Hardness
Different types of hardness are in relation with each other and together with the pH and the alkalinity of the
water they determine the equilibrium situation of the water, determined and specified by the RSI.
In addition, the calcium hardness must be limited to:
Ca (ppm Ca CO3)
Type of cooling system Standard Energy recovery
Single pass < 500 < 2
Recirculating (with tower) < 500 not applicable
Closed loop < 1000 < 50
4. The Ryznar Stability Index (RSI)
The Ryznar Stability Index is a parameter for predicting whether water will tend to dissolve or precipitate
calcium carbonate. The adhesion of scaling depositions and their effect are different on different materials,
but the equilibrium of the water (scaling or corrosive) is only determined by its actual pH value and by the
saturation pH value (pHs). The saturation pH value is determined by the relationship between the calcium
hardness, the total alkalinity, the total solids concentration and the temperature.
The Ryznar Stability Index is calculated as follows:
RSI = 2*pHs - pH,
in which,

pH = measured pH (at room temp) of the water sample

pHs= pH at saturation
pHs is calculated from:
pHs = (9.3 + A + B) - (C + D),
in which,

A : depends on the total solids concentration

B : depends on the water temperature at the outlet of the heat exchanger

C : depends on the calcium hardness (CaCO3)

D : depends on the HCO3 concentration or M-alkalinity