Liebert himod - Steam Generating Humidifier; Principle of Operation; Figure 9 Operation Schematic

Component Operation and Maintenance 49
6.5 Steam Generating Humidifier
6.5.1 Principle of Operation
When the humidistat calls, the cylinder fills to 100% of the Full Load Amperage (FLA) or to the top of
the cylinder, whichever comes first. See Figure 9.
If it reaches 100% FLA, the water heats and boils away to a level giving 85% FLA.
Figure 9 Operation schematic
An electronic timer uses the rate of amp fall to determine the water level. The objective is to concen-
trate current-carrying minerals in the cylinder so that a smaller volume of water is required to pro-
duce the rated steam output.
This achieves the longest life for the disposable cylinder because of minimal electrode coverage and
use of less energy because the high concentration allows a minimal drain rate.
When 85% FLA is reached, the fill valve will open refilling cylinder to 100% FLA. On occasion, the
drain valve will also come on if water level is too low, indicating too high a concentration and the
requirement for a dilution of the water in the cylinder.
If the water reaches the top of the cylinder before 100% FLA, the fill valve shuts off via the high water
sensor and fill-boil-fill-boil cycle continues, cycling off the amber high water sensor light until the con-
centration becomes high enough to reach 100% FLA. The above described control process will then
take over.
CONDENSATE RETURN (OPTIONAL)
1” AIR
GAP
FILL
CUP
1. INLET CHAMBER
3. WATER OVERFLOW
CHAMBER (SAFETY DRAIN
IN CASE OF FILL VALVE/
CONTROL BOARD FAILURE)
STRAINER
FILL
VALVE
TAP
WATER
SUPPLY
DRAIN
CONNECTION
DRAIN
PAN
DRAIN CANAL
(OPEN TO ATMOSPHERE)
DRAIN
VALVE
CYLINDER
1
2
3
2
. FILL CHAMBER
STEAM HOSE
ELECTRODES
HIGH WATER SENSOR