TM 5-3895-374-24-1
DRYER DRUM GAS ANALYSIS
FOR NATURAL GAS, OIL AND LP _
Gas analyses are used to indicate the air-fuel ratio and to indicate the degree of completeness of combustion. If the
mixing is poor, an excess of air must be supplied so that every particle of fuel will contact some air and burn. Unburned
fuel is simply wasted since it does not contribute heat to the process.
A critical step in every dryer drum gas analysis is the placement of the sample tube. The applicability of the readings
depends directly on the location from which the sample is drawn. To give you an idea of the recommended placement, we
have included a drawing in this section. Refer to “Typical Sample Tube Installation for Dryer Drum Gas Analysis”.
The procedures used to make an accurate gas analysis vary not only with the method employed but also with the
manufacturer of the equipment. In most instances good readings require that the manufacturers instructions be adhered
to rigidly.
Conditions to perform a good analysis.
1.
Use a reliable gas analyzer.
2.
Sample pipe must be installed in the dryer drum to eliminate reading stray 02, overheated RAP or overheated AC.
3.
Sample should be taken with average tonnage, moisture and firing rates.
4.
Allow at least 10 to 15 minutes running time at production rates before taking readings.
5.
Sample tubing from the sample pipe to the analyzer should be as short as possible. Tubing should be
approximately ¼ inch I.D. rubber, plastic or silicone.
6.
Gases should be sampled until instrument settles out, normally a few minutes depending on sample line size,
length, and pump volume.
Interpretation of gas readings.
EXAMPLE
Assuming a drum gas analysis is taken at production rates.
Readings Taken: 02 - 4%
CO - 2000 PPM
Combustibles - 2%
Problem: 3% 02 - is too low
CO - is too high
Combustibles are too high GJ73F-
HAUCK MANUFACTURING CO., P 0 Box 90, Lebanon, PA 17042 717-272-3051
12/90
Fax 717-273-9882 Telex 671-1457
(page 3-528)
