Issue:
Uniflair Humidifier Water Quality.

Product line:
Uniflair.

Environment:
Data Center Cooling.

Cause:

Resolution:
Theory of operation
In the electrode humidifier, current flowing between the electrodes in the water generates the heat necessary to boil the water and the amperometric transformer (TAM) regulates electric current in the humidifier by controlling water level and mineral concentration in the steam cylinder. This is accomplished by opening and closing the feed water solenoid valve and the cylinder electric drain valve. When steam is needed, the humidifier contact is closed, providing power to the immersed electrodes. When the current falls below the value required as a result of the fall in the water level, the feed water solenoid valve is opened.

The cylinder electric drain valve is opened at intervals depending on the characteristics of the feed water supply in order to maintain the optimum concentration of dissolved minerals in the water in the cylinder.

Feed water
Values for the feed water for medium-high level of conductibility of a humidifier with immersed electrodes:

		Limits
Description	Units	Minimum	Maximum
Hydrogen ion activity pH	-	7	8.5
Specific conductibility at 20°C σ R, 20°C	μS/cm	300	1250
Total dissolved solids TDS	mg/l	(1)	(1)
Residual fixed at 180°C R180	mg/l	(1)	(1)
Total hardness TH	mg/l	100(2)	100
Temporary hardness	mg/l	60(3)	300
Iron + manganese	mg/l Fe + Mn	0	0.2
Chlorides	ppm Cl	0	30
Silica	mg/l	0	20
Residual chloride	mg/l	0	0.2
Calcium sulphate	mg/l	0	100
Metallic impurities	mg/l	0	0
Solvents, diluents, soaps, lubricants	mg/l	0	0

(¹) Values dependent on the specific conductibility; in general: TDS @ 0,93 * s20; R180 @ 0,65 * s20
(²) Not lower than 200% of the Chloride content in mg/l di Cl-
(³) Not lower than 300% of the Chloride content in mg/l di Cl-

Udgivet til: Schneider Electric Danmark