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STEA
SERIES
Installation, Operation & Maintenance Manual
5
How The STE Works
STE
is an electrode humidifier. It produces steam for humidification by passing electrode
current through the water in the steam generator cylinder between metal electrodes. There are no
heater elements. Steam output is directly proportional to the conductivity of the water, and the amount
of electrode immersed in the water.
On a call for humidity, the STE controller will open the water fill valve (1) and allow water to enter the system. A
flow restrictor (2) prevents the unit from filling too quickly or with too much pressure. The water flows up the fill tube (3)
and into the fill cup (7), where it flows over the conductivity probes (6), which feed the water conductivity back to the
controller for analysis. Water then flows over the dam in the fill cup (7), which creates a 1" air gap to prevent backflow of
contaminated water into the feed lines, and through the fill tube (4) and into the bottom of the steam cylinder (11).
As the water fills the cylinder, it will reach the electrodes (10) and current will begin to flow. As the water continues to fill
the cylinder, the current will increase, and this is monitored by an amperage transformer placed on one of the power wires
(9). When the desired current is reached, the fill valve will close (1) and the water will then begin to warm and produce
steam. If the water reaches the cylinder full probes (8) prior to reaching the desired current level, the fill valve (1) will be
closed to prevent overflow. If the current rises too much as the water fills the cylinder, the drain valve or pump (13) will be
activated to drain away some water and reduce the current flow.
Periodically, based on the incoming water conductivity, the unit will drain some water to reduce the mineral concentration.
A strainer (12) in the cylinder helps to prevent mineral debris from jamming the drain valve (13).
If there is no water in the cylinder, there will be no current flow and no steam production. The electrodes do not burn out,
but they will eventually become comletely coated with mineral and the cylinder will then need to be replaced or cleaned.
