Mud-logger GC
6Pages

PRE-CONFIGURED GCs Mud-logger System Overview The Mud-logger GC system is designed to provide a continous reading of total hydrocarbons in a gas stream, while periodically performing a chromatographic separation of the sample to determine the composition of the sample gas stream. This is accomplished with a flow restrictor for the monitoring FID (#2), and 10-port gas sampling valve & sample loop for the speciation FID (#1). In the temperature-programmable column oven, the 3-meter Hayesep-D Column Valve oven packed column efficiently separates the oven constituent hydrocarbons peaks (C1-C6). Restrictor Valve Hayesep-D packed column Dual FID detectors In the heated valve oven, the sample inlet is split between the 10-port gas sampling valve and the restrictor. The restrictor controls the sample 30µL sample flow rate for the hydrocarbon monitoring FID (#2). The gas sampling loop valve periodically injects the contents of the sample loop onto the column for speciation by FID #1. In the temperature-programmable (ambient to 400oC) column oven, the 3-meter Hayesep-D packed Sample in Sample out column efficiently separates the hydrocarbons up to C6. Valve injections are automated by the built-in PeakSimple data system, and the timing is determined by the user. 3-meter Hayesep-D packed column Designated as FID #1, the speciation FID signal occupies channel 1. FID #2, the total hydrocarbon monitor, is displayed on channel 2. Using Data logger mode, PeakSimple will display a scaled and calibrated result in large numbers for at-a-glance visibility. PeakSimple has an alarm function which you can set to alert you when the system receives out-of-range readings. A built-in, “whisper quiet” air compressor supplies the combustion air for both FID detector

PRE-CONFIGURED GCs Mud-logger Theory of Operation The sample gas stream is connected to the bulkhead fitting on the front of the valve oven. Inside the valve oven, the sample flow is split through a “T.” On one side of the T, the flow is directed through a restrictor, through the sampling loop on the 10-port valve, and on to the column and FID #1 for separation and detection. The other side of the T directs the sample gas stream through a much longer restrictor, and on to FID #2. FID #2 10-port gas sampling valve with 30uL sample loop The sample gas stream is connected here. “Tee” Heated...

General Operating Procedure 1. Set the valve oven temperature to 90oC. 2. For FID #1, set the amplifier gain switch to MEDIUM. For FID #2, set the gain switch to LOW. 3. Set the FID hydrogen flow to 25mL/minute, and the FID air supply flow to 250mL/minute. The approximate pressures required to achieve these flow rates are printed on the right-hand side of your Mud-logger GC. 4. Ignite each FID by holding up the ignitor switch for a couple of seconds until you hear a small POP. The ignitor switches are located on the front panel of the GC. Verify that the flame is lit by holding the shiny...

7. In PeakSimple, open the Channel details dialog box for channel 2. The Datalogger mode area is in the lower right corner of the Channel details dialog box. Click in the checkbox to activate Datalogger mode, then enter the gain factor which will multiply the 300 millivolt signal to produce the desired concentration unit. For example: 300 x .33 = 100 if the desired unit is percent; or 300 x 3333 = 1,000,000 if the desired unit is parts per million (ppm). The FID #2 signal times the gain factor will display in the channel 2 chromatogram window. 8. Enter an isothermal temperature program in...

The top chromatogram window is channel 1, displaying the FID #1 signal response to a valve injection of natural gas standard. The bottom chromatogram window, in Data logger mode, shows the concentration of hydrocarbons in the desired unit. Designate the unit in the Channel details dialog box, in the Data logger mode section. FID #1 gain = MED FID #1 temp = 150oC FID #1 ignitor = -700 Valve temp = 90oC FID #2 gain = LOW FID #2 temp = 150oC FID #2 ignitor = -700 Temperature program: Initial Hold Ramp Final 180oC 100.00 0.00 180oC

Expected Performance Column Backflush to FID #1 The Mud-logger GC system is plumbed for backflush. This gives you the option to set the valve program to backflush the heavier hydrocarbons after the desired peaks have been separated. In the example below, the valve was set to backflush after the elution of ethane, and the C3-C6 produce one large peak. FID gain = HIGH FID temp = 300oC FID ignitor = -600 Valve temp = 90oC Temperature program: Initial Hold Ramp