Troubleshooting; Product Description; System Operation; Troubleshooting Aids - DeVilbiss iFill 535D Servicehandbuch

proDuct Description

The DeVilbiss iFill Personal Oxygen Station uses a dual-
pressure head compressor to simultaneously power a pressure
swing adsorption oxygen generation system and a pneumatic
pressure intensifier. It is designed to provide supplemental
oxygen to fill portable cylinders for ambulatory use.
Oxygen cylinders are attached to the iFill unit with a coupler
and cylinder nipple set. The application-specific coupler helps
to insure that other cylinders cannot inadvertently be
connected to the iFill system .
The iFill station is designed to fill various sizes of portable
oxygen cylinders . Cylinders are available with an integrated
oxygen conserving device or continuous flow regulator
mounted on top .
An onboard Oxygen Sensing Device (DeVilbiss OSD®)
monitors the oxygen concentration level to insure that it
remains within specification (93% ± 3%).

sYstem operation

The iFill's dual-pressure head compressor draws in room air
through air filters to power the oxygen generation system and
the pressure intensifier. The output of one of the compressor
heads is routed to a rotary valve. The valve directs the flow of
compressed air to a pair of sieve beds in the unit in a timed
sequence that is controlled by a PC board . As air passes
through the beds, nitrogen is separated from the air stream
which results in higher concentrations of oxygen exiting the
bed . As one bed is being pressurized, the other bed is
depressurized allowing the nitrogen to be discharged from the
unit through an exhaust muffler connected to the rotary valve.
Oxygen from the pressurized bed is directed through a check
valve to an accumulator tank .
When the iFill Personal Oxygen Station is first turned on to
begin filling a cylinder, the three-way valve is held energized
routing all oxygen from the accumulator tank through the final
bacteria filter to the Oxygen Sensing Device (OSD) until the
required purity is achieved (approximately 4 minutes) . This
period when the unit is running but not filling a cylinder is
referred to as the warm up mode . Once the oxygen purity is
reached, the three-way valve deenergizes routing all oxygen
from the accumulator tank and final bacteria filter to the inlet of
the intensifier. The intensifier accepts the low pressure oxygen
and boosts the pressure of the gas to approximately 2000 PSI
for filling portable oxygen cylinders.
This is done by using the second compressor head to supply
compressed air to drive the two-stage intensifier. The
intensifier's main body or power cylinder houses the drive
piston which in turn "drives" the pistons that are located in the
1st and 2nd stage respectively. The flow of the compressed air
to the intensifier is controlled with a four-way valve. After being
used to compress the oxygen, the exhaust air from the power
cylinder is routed back to the intake of the compressor to help
reduce the overall energy consumption of the filling station.
Oxygen is supplied to the intensifier at a pressure of 30 to 45
LT-1929
T R O U B L E S H O O T I N G
psi . It enters the 1st stage cylinder through an inlet check valve
and is pressurized to approximately 200 to 500 psi . This
pressure will vary based on what part of the filling cycle it is on.
The oxygen then passes through the outlet check valve and is
transferred through the inter-stage tube to the 2nd stage
cylinder . It enters the 2nd stage through another inlet check
valve where it is pressurized further . The 2nd stage pressure
will also vary according to the filling cycle. Oxygen passes
through the 2nd stage outlet check valve and enters the
portable cylinder attached to the fill connector.
The cylinder pressure will continue to increase until it reaches
approximately 2000 psi. When the cylinder is filled, the iFill
station will automatically turn off and the indicator panel light
will show full .
A pneumatic diagram of the system is shown in Figure 21 .

trouBLesHooting aiDs

normal unit operation & problem solving
tips:
IMPORTANT: You must understand the following Normal
Operation before attempting to troubleshoot the 535 iFill.
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equipment:

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When the unit is plugged in, all control panel lights
illuminate briefly and the audible alert sounds a short
beep . The standby light remains on .
After attaching a cylinder to the quick connect coupler and
pressing the start button, the standby light goes out and
the filling light comes on.
The fan, rotary valve, and four-way valve operate
continuously for 10 seconds, but the compressor remains
off .
After 10 seconds the compressor comes on and the
oxygen generating system and intensifier begin to operate.
During this time the three-way valve routes all oxygen from
the accumulator tank to the main PC board's Oxygen
Sensing Device (OSD) at a flow of 2.5 to 3 LPM.
When the OSD senses 91% oxygen, normally within 3 to 4
minutes, the three-way valve routes all oxygen from the
accumulator tank to the intensifier, which begins filling the
cylinder .
Throughout the normal filling cycle, the three-way
NOTE
–
valve will cycle every 24 seconds to send a small sample
of gas to the OSD to verify a minimum purity of 90% . If the
OSD senses less that 90% purity, the unit reenters the
warm up mode .
When the cylinder is filled to approximately 2,000 PSIG,
the unit stops and the full light illuminates . The fan
continues to run for several minutes to cool down the unit;
then stops and completes the fill cycle.
Spare Light Control Panel: Plugs into the main PC board
allowing full access to the unit when the covers are
removed .
Spare Parts: Installed to verify faulty components
Flow Test Fixture: Connect to the three-way valve top
metal fitting to assist in isolating problems.