3.2.2 Connect the probe, insert it into the stack, and sample at a constant rate of 2 1pm (0.071 cfm). Continue sampling until the dry gas meter registers about 30 liters (1.1 ft3) or until visible liquid droplets are carried over from the first impinger to the second. Record temperature, pressure, and dry gas meter readings as required by Figure 4-5. 3.2.3 After collecting the sample, combine the contents of the two impingers and measure the volume to the nearest 0.5 ml. 3.3 Calculations. The calculation method presented is designed to estimate the moisture in the stack gas; therefore, other data, which are only necessary for accurate moisture determinations, are not collected. The following equations adequately estimate the moisture content, for the purpose of determining isokinetic sampling rate settings. 3.3.1 Nomenclature. Bum-Approximate proportion, by volume, of water vapor in the gas stream leaving the second impinger, 0.025. Bus Water vapor in the gas stream, proportion by volume. Mu-Molecular weight of water, 18.0 g/g-mole (18.0 lb/lb-mole). Pm-Absolute pressure (for this method, same as barometric pressure) at the dry gas meter. Patd Standard absolute pressure, 760 mm Hg (29.92 in. Hg). R-Ideal gas constant, 0.06236 (mm Hg) (m3)/ (g-mole) (°K) for metric units and 21.85 (in. Hg) (ft3)/lb-mole) (°R) for English units. Tm-Absolute temperature at meter, °K (°R). Tstd-Standard absolute temperature, 293°K (528° R). V=Final volume of impinger contents, ml. V1=Initial volume of impinger contents, ml. 2. Devorkin, Howard. et al. Air Pollution Source Testing Manual. Air Pollution Control District, Los Angeles, CA. November, 1963. 3. Methods for Determination of Velocity, Volume, Dust and Mist Content of Gases. Western Precipitation Division of Joy Manufacturing Co., Los Angeles, CA. Bulletin WP50. 1968. METHOD 5-DETERMINATION OF PARTICULATE EMISSIONS FROM STATIONARY SOURCES 1. Principle and Applicability 1.1 Principle. Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature in the range of 120±14 °C (248125 °F) or such other temperature as specified by an applicable subpart of the standards or approved by Administrator, U.S. Environmental Protection Agency, for a particular application. The particulate mass, which includes any material that condenses at or above the filtration temperature, is de termined gravimetrically after removal of uncombined water. 1.2 Applicability. This method is applicable for the determination of particulate emissions from stationary sources. 2. Apparatus 2.1 Sampling Train. A schematic of the sampling train used in this method is shown in Figure 5-1. Complete construction details are given in APTD-0581 (Citation 2 in Bibliography); commercial models of this train are also available. For changes from APTD0581 and for allowable modifications of the train shown in Figure 5-1, see the following subsections. The operating and maintenance procedures for the sampling train are described in APTD-0576 (Citation 3 in Bibliography). Since correct usage is important in obtaining valid results, all users should read APTD-0576 and adopt the operating and maintenance procedures outlined in it, unless otherwise specified herein. The sampling train consists of the following components: IMPINGER TRAIN OPTIONAL, MAY BE REPLACED BY AN EQUIVALENT CONDENSER 2.1.1 Probe Nozzle. Stainless steel (316) or glass with sharp, tapered leading edge. The angle of taper shall be <30° and the taper shall be on the outside to preserve a con stant internal diameter. The probe nozzle shall be of the button-hook or elbow design, unless otherwise specified by the Administrator. If made of stainless steel, the nozzle Figure 5-1. Particulate-sampling train. for shall be constructed from seamless tubing; other materials of construction may be used, subject to the approval of the Administrator. A range of nozzle sizes suitable isokinetic sampling should be available, e.g., 0.32 to 1.27 cm (% to 1⁄2 in.)—or larger if higher volume sampling trains are used-inside diameter (ID) nozzles in increments of 0.16 cm (6 in.). Each nozzle shall be calibrated according to the procedures outlined in Section 5. 2.1.2 Probe Liner. Borosilicate or quartz glass tubing with a heating system capable of maintaining a gas temperature at the exit end during sampling of 120±14 °C (248±25 °F), or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. (The tester may opt to operate the equipment at a temperature lower than that specified.) Since the actual temperature at the outlet of the probe is not usually monitored during sampling, probes constructed according to APTD-0581 and utilizing the calibration curves of APTD-0576 (or calibrated according to the procedure outlined in APTD-0576) will be considered acceptable. Either borosilicate or quartz glass probe liners may be used for stack temperatures up to about 480 °C (900 °F); quartz liners shall be used for temperatures between 480 and 900 °C (900 and 1,650 °F). Both types of liners may be used at higher temperatures than specified for short periods of time, subject to the approval of the Administrator. The softening temperature for borosilicate is 820 °C (1,508 °F), and for quartz it is 1,500 °C (2,732 °F). Whenever practical, every effort should be made to use borosilicate or quartz glass probe liners. Alternatively, metal liners (e.g., 316 stainless steel, Incoloy 825,2or other corrosion resistant metals) made of seamless tubing may be used, subject to the approval of the Administrator. 2.1.3 Pitot Tube. Type S, as described in Section 2.1 of Method 2, or other device approved by the Administrator. The pitot tube shall be attached to the probe (as shown in Figure 5-1) to allow constant monitoring of the stack gas velocity. The impact (high pressure) opening plane of the pitot tube shall be even with or above the nozzle entry plane (see Method 2, Figure 2–6b) during sampling. The Type S pitot tube assembly shall have a known coefficient, determined as outlined in Section 4 of Method 2. 2.1.4 Differential Pressure Gauge. Inclined manometer or equivalent device (two), as described in Section 2.2 of Method 2. One manometer shall be used or velocity head (Aẞ) readings, and the other, for orifice differential pressure readings. 2 Mention of trade names or specific product does not constitute endorsement by the Environmental Protection Agency. 2.1.5 Filter Holder. Borosilicate glass, with a glass frit filter support and a silicone rubber gasket. Other materials of construction (e.g., stainless steel, Teflon, Viton) may be used, subject to approval of the Administrator. The holder design shall provide a positive seal against leakage from the outside or around the filter. The holder shall be attached immediately at the outlet of the probe (or cyclone, it used). 2.1.6 Filter Heating System. Any heating system capable of maintaining a temperature around the filter holder during sampling of 120114 °C (248±25 °F), or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. Alternatively, the tester may opt to operate the equipment at a temperature lower than that specified. A temperature gauge capable of measuring temperature to within 3 °C (5.4 °F) shall be installed so that the temperature around the filter holder can be regulated and monitored during sampling. Heating systems other than the one shown in APTD-0581 may be used. 2.1.7 Condenser. The following system shall be used to determine the stack gas moisture content: Four impingers connected in series with leak-free ground glass fittings or any similar leak-free non-contaminating fittings. The first, third, and fourth impingers shall be of the Greenburg-Smith design, modified by replacing the tip with 1.3 cm (1⁄2 in.) ID glass tube extending to about 1.3 cm (1⁄2 in.) from the bottom of the flask. The second impinger shall be of the Greenburg-Smith design with the standard tip. Modifications (e.g., using flexible connections between the impingers, using materials other than glass, or using flexible vacuum lines to connect the filter holder to the condenser) may be used, subject to the approval of the Administrator. The first and second impingers shall contain known quantities of water (Section 4.1.3), the third shall be empty, and the fourth shall contain a known weight of silica gel, or equivalent desiccant. A thermometer, capable of measuring temperature to within 1 °C (2 °F) shall be placed at the outlet of the fourth impinger for monitoring purposes. Alternatively, any system that cools the sample gas stream and allows measurement of the water condensed and moisture leaving the condenser, each to within 1 ml or 1 g may be used, subject to the approval of the Administrator. Acceptable means are to measure the condensed water either gravimetrically or volumetrically and to measure the moisture leaving the condenser by: (1) monitoring the temperature and pressure at the exit of the condenser and using Dalton's law of partial pressures; or (2) passing the sample has stream through a tared silica gel (or equivalent desiccant) trap with exit gases |