(April, 2013)
DRH Series GEN1 Ultrasonic Humidifi er Installation, Operation & Maintenance Manual
1-5
1.5 General
Design
The
DRH
Ultrasonic Humidifi er directly atomizes water, producing a fi ne mist. The humidifi er incorporates
high frequency nebulizers to produce ultrasonic waves, a fan to propel the mist out, and an automatic water
supply mechanism to maintain the supply water at a constant level. When conducting routine maintenance, it is
important to clean the air fi lter and water tank because it signifi cantly affects the humidifying capacity and life of
the ultrasonic nebulizers.
1.6 Main Parts
1.6.1 Ultrasonic Nebulizer Unit
This consists of a modular assembly located in the
bottom of the water tank incorporating a 1.6Mhz
power oscillator on and a piezoelectric transducer.
The transducer vibrates at that frequency, developing
ultrasonic columnar waves in the water and
producing a fi ne mist above that column.
1.6.2 Mist Guide
The mist guide carries the mist off the top of the
columnar wave and directs it up and out of the
humidifi er.
1.6.3 High Water Float Switch
For maximum atomization, it is essential the water
level in the tank be constantly maintained. The High
Water Float Switch is an input to the Level Controller.
It is open when the water level is below the optimal
level and is closed when the water level reaches the
maximum level.
1.6.4 Low Water Float Switch
Operating the humidifi er when the water level is
below the top of the transducers will damage the Ul-
trasonic Nebulizer Unit. The Low Water Float Switch
is an input to the Level Controller. It is open when
the water level is near an unsafe level and is closed
when the water level is at a minimal level.
1.6.5 Fan
The 24VDC fan or fans both lightly pressurizes the air
above the water to provide a path for the mist to pass
through the Mist Tubes and provides a sheet of air to
carry the mist away from the humidifi er into the room.
The fan is controlled by the Level Controller.
1.6.6 Air Filter
The Air Filter removes coarse dust from the air and
prevents the humidifi er water tank from becoming
dirty which would affect the mist output.
1.6.7 Water Fill Valve Solenoid
The Water Fill Valve Solenoid is a 24VDC solenoid
that allows water from the water supply to enter into
the tank when energized by the Level Controller.
There is an orifi ce to restrict the fl ow of water.
1.6.8 Water Supply Valve
(To be provided by the user)
A valve must be installed upstream from the humidi-
fi er for service and maintenance. The valve must be
rated for DI water.
1.6.9 Water Supply Tubing
(To be provided by the user)
Water supply tubing must be provided to connect the
water supply to the water fi lter/strainer in the back
of the unit. The fi lter/strainer is equipped with a ¼”
compression fi tting. Utilize ¼” stainless steel or poly
tubing rated for use with DI water.
1.6.10 Drain and Overfl ow Assembly
The Drain and Overfl ow Assembly contains a 24
VDC drain solenoid valve, an overfl ow pipe and a
drain outlet. The drain valve solenoid is controlled by
the Level Controller to drain water from the tank via
the drain outlet. If the water level in the tank exceeds
the height of the overfl ow pipe, the excess water is
diverted to the drain outlet.
1.6.11 Temperature
Sensor
The temperature sensor monitors the temperature
of the tank and is read by the Level Controller which
prevents overheating and freeze protection