Oxygen Concentrator
PN 14940837 B — 11
Theory of Operation
Introduction
The Companion 5 is a stationary medical device used to extract
oxygen from the atmosphere, concentrate it, and present the
oxygen to the patient. The device will operate in Continuous Flow
Mode. In Continuous Flow Mode the oxygen is provided at a con-
stant flow rate between 0.5 and 5.0 LPM (Continuously Variable).
Table 2 below lists the major internal components of the con-
centrator and their functions. Reference Table 2 and Figure 3 (on
the following page) for clarification while reading the Theory of
Operation Section of the manual.
Item
Function
Intake Filter
Provides HEPA level filtration for intake to compres-
sor.
Compressor
Pump that routes air into and through the concen-
trator.
Cooling Fan
Cools the compressor area.
4-Way
Solenoid
Valve
Routes air flow through one sieve bed and vents
the purged air to the atmosphere from the other
bed. Responsible for alternating flow between the
beds.
Sieve Beds
(2)
Chemically adsorbs nitrogen molecules from the
air.
Orifice
Routes a larger portion of air exiting one sieve bed
back through the other bed for purging.
Flapper Valve
Routes a smaller portion of air exiting one sieve
bed into the product holding tank. Prevents back
flow from product tank to sieve bed
Product
Holding Tank
Holds concentrated oxygen prior to its regulation
and delivery to the patient.
Pressure
Regulator
Reduces the outlet pressure to be compatible with
the flow meter and accessories.
OCSI Sensor
Detects oxygen concentration of flow exiting the
concentrator (OCSI models only). Sends a signal to
activate alarm if concentration is too low.
Flow Control
Valve
Integral needle valve that controls volumetric flow
(LPM) to the patient. Is read against the printed
scale.
HEPA Filter
HEPA level filtration of outlet flow.
Printed
Circuit Board
(PCB)
Responsible for all of the electrical operation of the
concentrator. Contains a programmable micropro-
cessor that controls valve timing, alarm indications,
and OCSI functions (if applicable).
Table 2: Internal Components of Concentrator
Pressure Swing Adsorption
The CAIRE Companion 5 utilizes the Pressure Swing Adsorption
(PSA) Process to concentrate oxygen gas from ambient air. In the
PSA process, a compressor draws ambient air into the machine
through an intake filter. The compressor then forces the filtered air
into a solenoid valve which directs the air into one of two tanks
that are full of a molecular sieve material, referred to as sieve
beds. As the pressure in sieve bed 1 increases, nitrogen molecules
are removed from the ambient air and are stored in the sieve
material. The gas that exits sieve bed 1 is highly-concentrated
oxygen. The majority of this gas flows through an orifice to sieve
bed 2 and is used to purge the stored nitrogen gas from its sieve
material. The remainder of the oxygen gas is directed through a
flapper valve to the product holding tank. Here, it is stored for
delivery to the patient.
Sieve bed 1 continues to pressurize until the sieve material is
completely saturated with nitrogen. At this time the printed circuit
board (PCB) switches the state of the solenoid valve, dumping
pressurized air in sieve bed 1 back into the atmosphere via the
purge muffler. Simultaneously, the valve now directs the com-
pressed air into sieve bed 2, which has been completely purged of
nitrogen gas and is ready for nitrogen adsorption/oxygen concen-
tration. This cycle continuously repeats pressurizing and depressur-
izing the sieve beds, feeding concentrated oxygen to the product
holding tank.
