Steam Generating Humidifier; Principle Of Operation; Figure 9 Operation Schematic - Liebert Himod Operation & Maintenance Manual

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
1. INLET CHAMBER
2. FILL CHAMBER
3. WATER OVERFLOW
CHAMBER (SAFETY DRAIN
IN CASE OF FILL VALVE/
CONTROL BOARD FAILURE)
STRAINER
TAP
WATER
SUPPLY
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)
FILL
CUP
1 2 3
FILL
VALVE
DRAIN
CONNECTION
DRAIN CANAL
(OPEN TO ATMOSPHERE)
STEAM HOSE
1" AIR
GAP
ELECTRODES
CYLINDER
DRAIN
VALVE
DRAIN
PAN
Component Operation and Maintenance
HIGH WATER SENSOR
49