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3.1.1 Set up the equipment as shown in Figure 3-1, making sure all connections are leak-free, Place the probe in the stack at a sampling point and purge the sampling line.
3.1.2 Draw sample into the analyzer.
3.2.1 Evacuate the flexible bag. Set up the equipment as shown in Figure 3–2 with the bag disconnected. Place the probe in the stack and purge the sampling line. Connect the bag, making sure that all connections are tight and that there are no leaks.
3.2.2 Sample at a rate proportional to the stack velocity.
3.3.1 Determine the co,, 0, and Co concentrations as soon as possible. Make as many passes as are necessary to give constant readings. If more than ten passes are necessary, replace the absorbing solution.
3.3.2 For grab sampling, repeat the sampling and analysis until three consecutive samples vary no more than 0.5 percent by volume for each component being analyzed.
3.3.3 For integrated sampling, repeat the analysis of the sample until three consecutive analyses vary no more than 0.2 percent by volume for each component being analyzed.
4.1 Carbon dioxide. Average the three consecutive runs and report the result to the nearest 0.1% CO,.
4.2 Excess air. Use Equation 3-1 to calculate excess air, and average the runs. Report the result to the nearest 0.1% excess air. % EA=
(% 02) – 0.50 % CO) 0.264(% N2) – (% 02) +0.5(% cO) X 100
equation 3-1 where:
%EA=Percent excess air.
ume, dry basis. 0.264=Ratio of oxygen to nitrogen in air
by volume. 4.3 Dry molecular weight. Use Equation 3-2 to calculate dry molecular weight and average the runs. Report the result to the
esult to the nearest tenth. Ma=0.44( % CO,) +0.32(%0,)
equation 3-2 where:
Ma=Dry molecular weight, lb./lb-mole. %CO,=Percent carbon dioxide by volume,
dry basis. %0,=Percent oxygen by volume, dry
basis. %N=Percent nitrogen by volume, dry
0.44=Molecular weight of carbon dioxide
divided by 100. 0.32=Molecular weight of oxygen divided
by 100. 0.28=Molecular weight of nitrogen and
CO divided by 100. 5. References.
Altshuller, A. P., et al., Storage of Gases and Vapors in Plastic Bags, Int. J. Air & Water Pollution, 6:75–81, 1963.
Conner, William D., and J. S. Nader, Air Sampling with Plastic Bags, Journal of the American Industrial Hygiene Association, 25:291–297, May-June 1964.
Devorkin, Howard, et al., Air Pollution Source Testing Manual, Air Pollution Control District, Los Angeles, Calif., November 1963. METHOD 4-DETERMINATION OF MOISTURE
IN STACK GASES
1.1 Principle. Moisture is removed from the gas stream, condensed, and determined volumetrically.
1.2 Applicability. This method is applicable for the determination of moisture in stack gas only when specified by test procedures for determining compliance with New Source Performance Standards. This method does not apply when liquid droplets are present in the gas streami and the moisture is subsequently used in the determination of stack gas molecular weight.
Other methods such as drying tubes, wet bulb-dry bulb techniques, and volumetric condensation techniques may be used.
2.1 Probe-Stainless steel or Pyrex 2 glass sufficiently heated to prevent condensation and equipped with a filter to remove particulate matter.
2.2 Impingers-Two midget impingers, each with 30 ml. capacity, or equivalent.
2.3 Ice bath container-To condense moisture in impingers.
2.4 Silica gel tube (optional)-To protect pump and dry gas meter.
2.5 Needle valve-To regulate gas flow rate.
2.6 Pump-Leak-free, diaphragm type, or equivalent, to pull gas through train.
2.7 Dry gas meter—To measure to within 1% of the total sample volume.
2.8 Rotameter-To measure a flow range from 0 to 0.1 c.f.m.
2.9 Graduated cylinder-25 ml.
2.10 Barometer--Sufficient to read to within 0.1 inch Hg.
2.11 Pitot tube-Type s, or equivalent, attached to probe so that the sampling flow
1 If liquid droplets are present in the gas stream, assume the stream to be saturated, determine the average stack gas temperature by traversing according to Method 1, and use a psychrometric chart to obtain an approximation of the moisture percentage.
2 Trade name.
rate can be regulated proportional to the constant rate of 0.075 c.f.m. or at a rate prostack gas velocity when velocity is varying portional to the stack gas velocity. Continue with time or a sample traverse is conducted. sampling until the dry gas meter registers 1 3. Procedure.
cubic foot or until visible liquid droplets are 3.1 Place exactly 5 ml. distilled water in carried over from the first impinger to the each impinger. Assemble the apparatus with second. Record temperature, pressure, and out the probe as shown in Figure 4-1. Leak dry gas meter readings as required by Figure check by plugging the inlet to the first im- 4-2. pinger and drawing a vacuum. Insure that 3.3 After collecting the sample, measure flow through the dry gas meter is less than the volume increase to the nearest 0.5 ml. 1% of the sampling rate.
(Ve-Vi) PH20RT Std
equation 4-1 where:
PH20=Density of water, 1 g./ml. Vwc=Volume of water vapor collected
Tsta= Absolute temperature at standard (standard conditions), cu. ft. Ve=Final volume of impinger contents,
conditions, 530° R. ml.
Psta=Absolute pressure at standard conVi=Initial volume of impinger con
ditions, 29.92 inches Hg. tents, ml. R=Ideal gas constant, 21.83 inches MH20=Molecular weight of water, 18 lb./ Hg—cu. ft./lb. mole-°R.
4.2 Gas volume.
Figure 4-2. Field moisture determination.
Tm = Absolute temperature at meter (°F+
in. Hg ( Tm equation 4-2 where: Vme =Dry gas volume through meter at
standard conditions, cu. ft. Vm =Dry gas volume measured by meter,
cu. ft. Pm =Barometric pressure at the dry gas
meter, inches Hg. Psta=Pressure at standard conditions, 29.92
inches Hg. Tstd=Absolute temperature at standard
conditions, 530° R.
equation 4-3 where: Bwo=Proportion by volume of water vapor
in the gas stream, dimensionless. Vwc = Volume of water vapor collected
(standard conditions), cu. ft. Vmc =Dry gas volume through meter
(standard conditions), cu. ft. Bwm=Approximate volumetric proportion
of water vapor in the gas stream leaving the impingers, 0.025.
Air Pollution Engineering Manual, Daniel son, J. A. (ed.), U.S. DHEW, PHS, National Center for Air Pollution Control, Cincinnati, Ohio, PHS Publication No. 999-AP-40, 1967.
Devorkin, Howard, et al., Air Pollution Source Testing Manual, Air Pollution Control District, Los Angeles, Calif., November 1963.
Methods for Determination of Velocity, Volume, Dust and Mist Content of Gases, Western Precipitation Division of Joy Manufacturing Co., Los Angeles, Calif., Bulletin WP-50. 1988.
METHOD 5—DETERMINATION OF PARTICULATE
EMISSIONS FROM STATIONARY SOURCES
1.1 Principle. Particulate matter is withdrawn isokinetically from the source and its weight is determined gravimetrically after removal of uncombined water.
1.2 Applicability. This method is applicable for the determination of particulate emissions from stationary sources only when specified by the test procedures for determining compliance with New Source Performance Standards.
2.1 Sampling train. The design specifications of the particulate sampling train used by EPA (Figure 5-1) are described in APTD0581. Commercial models of this train are available.
2.1.1 Nozzle-Stainless steel (316) with sharp, tapered leading edge.
2.1.2 Probe-Pyrex 1 glass with a heating system capable of maintaining a minimum gas temperature of 250° F. at the exit end during sampling to prevent condensation from occurring. When length limitations (greater than about 8 ft.) are encountered at temperatures less than 600° F., Incoloy 825 1, or & uivalent, may be used. Probes for sampling gas streams at temperatures in excess of 600° F. must have been approved by the Administrator.
2.1.3 Pitot tube-Type S, or equivalent, attached to probe to monitor stack gas velocity.
2.1.4 Filter Holder-Pyrex 1 glass with heating system capable of maintaining minimum temperature of 225° F.
2.1.5 Impingers / Condenser-Four impingers connected in series with glass ball joint fittings. The first, third, and fourth impingers are of the Greenburg-Smith design, modified by replacing the tip with a 1/2-inch ID glass tube extending to one-half inch from the bottom of the flask. The second im. pinger is of the Greenburg-Smith design with the standard tip. A condenser may be used in place of the impingers provided that the moisture content of the stack gas can still be determined.
2.1.6 Metering system-Vacuum gauge, leak-free pump, thermometers capable of measuring temperature to within 5° F., dry gas meter with 2% accuracy, and related equipment, or equivalent, as required to maintain an isokinetic sampling rate and to determine sample volume.
2.1.7 Barometer-To measure atmospheric pressure to +0.1 inches Hg.
2.2 Sample recovery.
2.2.1 Probe brush--At least as long as probe.
Glass wash bottles-Two.
2.3.3 Analytical balance-To measure to +0.1 mg.
2.3.4 Trip balance-300 g. capacity, to measure to +0.05 g.
3.1.1 Filters Glass fiber, MSA 1106 BH 1, or equivalent, numbered for identification and preweighed.
3.1.2 Silica gel-Indicating type, 6-16 mesh, dried at 175° C. (350° F.) for 2 hours.
1 Trade name.
Figure 5-1. Particulate-sampling train. 3.3.2 Desiccant-Drierite,i indicating. Leak check the sampling train at the sam4. Procedure.
pling site by plugging up the inlet to the fil4.1 Sampling
ter holder and pulling a 15 in. Hg vacuum. A 4.1.1 After selecting the sampling site and leakage rate not in excess of 0.02 c.f.m. at a the minimum number of sampling points, vacuum of 15 in. Hg is acceptable. Attach determine the stack pressure, temperature, the probe and adjust the heater to provide a moisture, and range of velocity head.
gas temperature of about 250° F. at the probe 4.1.2 Preparation of collection train. outlet. Turn on the filter heating system. Weigh to the nearest gram approximately 200 Place crushed ice around the impingers. Add g. of silica gel. Label a filter of proper diam more ice during the run to keep the tempereter, desiccate 2 for at least 24 hours and ature of the gases leaving the last impinger weigh to the nearest 0.5 mg. in a room where as low as possible and preferably at 70° F., the relative humidity is less than 50%. Place or less. Temperatures above 70° F. may result 100 ml. of water in each of the first two in damage to the dry gas meter from either impingers, leave the third impinger empty, moisture condensation or excessive heat. and place approximately 200 g. of preweighed silica gel in the fourth impinger. Set up the i Trade name. train without the probe as in Figure 5-1. 2 Dry using Drierite 1 at 70° F. +10° F.