BIRD MicroBlender 3800 - Overview of the 3800 MicroBlender Operation; Balance Module Operation; Proportioning Module Operation

SECTION 1:
OVERVIEW OF THE 3800 MICROBLENDER OPERATION
August, 1991
The 3800 MicroBlender mixes medical
grade compressed air and oxygen to
provide a pressurized gas source ranging
from 21% to 100% oxygen.
Figure 1
The two 50 + 5 PSIG (3.52 + 0.35 kg/cm?)
gas sources enter through the diameter
indexed (DISS) air and oxygen inlet
connectors located on the bottom, rear of
the blender (Fig. 2). Each inlet connector
incorporates a 30 micron particulate filter.
After being filtered, the gases travel
through duckbill check valves which
prevent possible reverse gas flow to
either the air or oxygen supply systems.
Figure 2
m BALANCE MODULE (FIGURE 3)
The two gases then enter the two-stage
Balance Module. The purpose of this mod-
ule is to equalize the operating pressure of
the air and oxygen gas sources before
entering the Proportioning Module. The
diaphragm responds to the difference in
pressure and directs the movement (stroke)
of each ball valve assembly contained
within the air and oxygen chambers. The
movement of each bail valve adjusts the
amount of gas flowing through the Balance
Module, equalizing the air and oxygen
pressures to the lower of the two pressures.
MODULES
BALANCE
MODULE
PROPOR-
TIONING
MODULE
ALARM BYPASS |
GAS SUPPLY PROPORTIONING/BLEED
SECTION SECTION
Figure 3, Bird Air-Oxygen Blender Diagram
m PROPORTIONING MODULE (FIGURE 4)
From the Balance Module the gases flow
into the Proportioning Module and are
mixed according to the oxygen percentage
selected on the external control knob. This
Module consists of a double ended valve
positioned between two vaive seats.
一 1 一