Mitsubishi Electric t-NEXT DF DX 011 P1 S, Руководство пользователя

Страница: 20 / 92

t-NEXT DF DX
T_tNEXTDFDX_0719_EN
20
MEHITS S.p.A.
DATA BOOK
WATER QUALITY OF THE HYDRAULIC CIRCUITS
The values shown in the table must be guaranteed during the entire life cycle of the machine.
Description Symbol Range
1 Hydrogen Ions pH 7.5 ÷ 9
2 Presence of calcium (Ca) and magnesium (Mg) Hardness 4 ÷ 8.5 °D
3 Chlorine ions Cl - < 150 ppm
4 Iron Ions Fe 3+ < 0.5 ppm
5 Manganese Ions Mn
2+
< 0.05 ppm
6 Carbon dioxide CO
2
< 10 ppm
7 Hydrogen sulphide H
2
S < 50 ppb
8 Oxygen O
2
< 0.1 ppm
9 Chlorine Cl
2
< 0.5 ppm
10 Ammonia NH
3
< 0.5 ppm
11 Ratio between carbonates and sulphates HCO
3
-/SO
42-
> 1
12 Sulphate ions SO
4--
< 100 ppm
13 Phosphate ions PO
43-
< 2.0 ppm
where: 1/1.78°D = 1°Fr with 1°Fr = 10 gr CaCO
3
/ m 3
ppm = parts for millions
ppb = part for billion
Explanatory notes:
ref.1:
A greater concentration of hydrogen ions (pH) than 9 implies a high risk of deposits, whereas a lower pH than 7 implies a high risk of
corrosion.
ref.2: The hardness measures the amount of Ca and Mg carbonate dissolved in the water with a temperature lower than 100°C (temporary
hardness). A high hardness implies a high risk of deposits.
ref.3: The concentration of chloride ions with higher values than those indicated causes corrosion.
ref. 4 - 5 - 8: The presence of iron and manganese ions and oxygen leads to corrosion.
ref.6 - 7: Carbon dioxide and hydrogen sulphide are impurities that promote corrosion.
ref.9: Usually in water from the waterworks it is a value of between 0.2 and 0.3 ppm. High values cause corrosion.
ref.10: The presence of ammonia reinforces the oxidising power of oxygen
ref.11: Below the value shown in the table, there is a risk of corrosion due to the trigger of galvanic currents between copper and other less noble
metals.
ref.12: The presence of sulphates ions triggers corrosion phenomenon.
ref.13: The presence of phosphates ions triggers corrosion phenomenon.
It is necessary to carry out periodic checks, with withdrawals at different points of the hydraulic system. During the first year of operation, checks are
recommended every 4 months which can be reduced every 6 months starting from the second year of operation.
WARNING:
It is necessary that, in the presence of dirty and / or aggressive waters, an intermediate heat exchanger is installed upstream of the heat
exchangers
ANTIFREEZE MIXTURES
In plants that are not adequately protected by heating cables, protect the hydraulic circuit with an anti-freeze mixture when the ambient air temperature can
drop below 5°C.
The values are indicative and may significantly vary depending on the glycol manufacturer. Refer to your glycol supplier for detail.
The values consider a precautionary difference of 5°C between the minimum ambient air temperature and the freezing temperature of the mixture.
In the hydraulic circuit do not send fluids other than water or mixtures with ethylene / propylene glycol.
If other products are provided, in addition to mixtures of water and ethylene or propylene glycol, contact the Manufacturer to check the compatibility with the
machine components.
Minimum ambient air temperature °C 5 0 -5 -10 -15 -20 -25 -30
ETHYLENE GLYCOL (suggested % in weight) % 0 12 20 30 35 40 45 50
Minimum ambient air temperature °C 5 2 -3 -9 -13 -17 -23 -29
PROPYLENE GLYCOL (suggested % in weight) % 0 10 20 30 35 40 45 50