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4.13
Continued.
NOTE:
4.14
Once the POWER switch has been depressed, the methane reactor will begin to
heat. After about a half hour the METHANE HEAT lamp should begin to cycle and
the pyrometer, Figures 1 and 6 (11), should indicate 290°C ± 10°C.
4.15
After a four hour interval, connect the equipment which is to receive the pure air to
the PURE AIR fitting and proceed as in Sections 4.7 and 4.8.
4.16
The operator should consult Figure 11 at this time to determine the time delay
before connecting the equipment to the pure air generator. The critical factor will be
the tolerance of the equipment for particular moisture levels.
4.17
Once connected to the using equipment the output flow can be regulated at the
pure air generator with the OUTPUT FLOW ADJUST valve, Figures 1 and 6 (10),
provided all flow devices external to the pure air generator are opened wide or
nonexistent. It is more common to open wide the OUTPUT FLOW ADJUST valve
on the pure air generator and control the flow at the using equipment with its own
flow control system; i.e., needle valves, differential flow controllers, etc.
4.18
Note that when the output flow is set with the OUTPUT FLOW ADJUST valve and
no external equipment is connected to the instrument, no methane reactor system
in the unit, and the rotameter vented directly to the atmosphere, the rotameter is
direct reading for output flow. See Figure 17. The operator must realize that when
any equipment is connected to the PURE AIR fitting the rotameter now operates in
a pressurized condition and is no longer direct reading and will indicate a lower flow
than is actually being delivered.
4.19
As an example, if the output pressure is set at 30-psig and the rotameter indicates
500-cc/min, then the full actual flow will be √3 times the rotameter indicated flow, or
866-cc/min, since the rotameter is now two atmospheres above ambient. This
same rule-of-thumb will apply at other pressure settings.
The calculation is: Actual Flow = √N+1 x R (N = Number of atmospheres above
ambient and R = Rotameter reading in LPM) as determined from the nomograph
(Figure 17).
DURING THIS "BURN-IN" INTERVAL COPIOUS AMOUNTS
OF WATER WILL BE DRIVEN FROM THE CATALYST AND
WILL CONTAMINATE ANY INSTRUMENTS WHICH MIGHT
BE CONNECTED TO THE PURE AIR GENERATOR AT THIS
TIME.
8
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