Galvanic Applied Sciences AccuChrome MA2963, Operation Manual

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Revision 4 9 12/15/2018
HELIUM
CARRIER
IN
SAMPLE
SAMPLE LOOP
COLUMN
MEASURING
REFERENCE
VENT
10 TO 100 PSIG
CALIBRATION
IN
JUMPER
1
2
3
4
5
6
7
8
9
SAMPLE
VENT
10
Air Supply
TCD
TO ATMOSPHERE
BUFFER COLUMN
60 PSIG
2.4 Typical GC Oven Arrangements
2.4.1 12-Minute Cycle Time Systems
The oven compartment for a typical 12-minute cycle time ACCUCHROME system is
composed of a Valco model DV22 10 port valve and two columns (some applications may
only require one).
• The valve, which performs sample injection and back flushing, is actuated by the carrier
gas. It is specifically designed for heavy-duty applications and is rated at 1,000,000
injections before requiring service. The injection volume is controlled by a fixed-volume
sample loop.
• Chromatography columns are employed to separate the natural gas. In two column natural
gas analysis systems, Column 1 separates all components except C6+, trapping C6+ for a
quick back flush out. Column 2 separates the remaining components. The total analysis
time is about 12 minutes, and the analysis is run isothermally at 70 ° C.
•
The temperature of the chromatograph oven is controlled to minimize retention time shifts
due to ambient temperature changes. The gas flow paths for single column and two column
configurations are shown in Figure 2-8 and Figure 2-9.
Figure 2-8: Single Column Flow Diagram