HJ/T 45-1999Stationary source emission. Determination of asphaltic smoke. Gravimetric method (English PDF)

7.2 Preparation before sampling

7.2.1 Treatment and constant weight of glass fiber filter cartridge

Use a pencil to number the filter cartridge (6.1.2); bake at 105°C for 2h, or bake at

400°C for 1h; then place in a desiccator to cool to room temperature; and weigh to constant weight by a balance, accurate to 0.1mg. "Constant weight" refers to the difference between two weighings with an interval of 24h; and the 3 # filter cartridge shall be no greater than 5.0mg.

7.2.2 Installation of the filter cartridge

Put the 3# filter cartridge (7.2.1) with constant weight into the filter cartridge holder;

gently press the filter cartridge mouth by the filter cartridge gland; and write down the number of filter cartridge.

7.2.3 Start the filter cartridge insulation system

Connect the heating socket of the filter cartridge holder to 220V power supply; and turn on the temperature control switch; so that the temperature of the filter cartridge holder raised to 42±10°C, and the indicator light shall flash.

7.2.4 Inspection

Inspect whether the connections and functions of all instruments in the sampling system are normal; and perform leak detection on the sampling system in accordance with the relevant provisions of 5.2.2.3 C in GB 16157-1996.

7.3 Sampling

Extend the sampling nozzle and front elbow of the sampling pipe (6.1.1) into the flue opening; the filter cartridge holder and cooling jacket shall be outside the flue opening;

and maintain the temperature of the filter cartridge holder insulation system at 42°C ±

10°C for sampling.

When the temperature of the asphaltic smoke is greater than or equal to 150 °C, the cooling device shall be activated. When the temperature of the asphaltic smoke is lower than 150 °C, the cooling device is not required. Adjust the cooling water flow rate so that the asphaltic smoke enters the filter cartridge holder at no lower than 40 °C.

The sampling steps are operated in accordance with items c ~ n in 8.3.5 of GB 16157-

1996.

After sampling, take out the sampling nozzle and front elbow; wipe off the shoot on the outside; put the 3# glass fiber filter cartridge into the numbered sample box; and bring the sampling nozzle, front elbow and sampling pipe together back to the laboratory for analysis.

8.1 Weighing the filter cartridge

Put the sampled filter cartridge in a desiccator for 24h, and then weigh it to a constant weight by a balance. The constant weight requirements are the same as (7.2.1).

Record the weight gain of 3# filter cartridge as deltaW1.

8.2 Washing the sampling pipe

When the concentration of asphaltic smoke is high, the sampling tube shall retain a small amount of asphaltic smoke. Wash the sampling nozzle, front bend and sampling pipe with cyclohexane (5.1). Combine the washing liquid and place it in a weighed beaker. Cover it by filter paper and let it evaporate naturally at room temperature and pressure. After the cyclohexane has evaporated completely; move the beaker to a desiccator for 24h to a constant weight; and record the weight gain of the beaker as

deltaW2.

9.1 Calculation of the concentration of asphaltic smoke

Appendix A (Standard)

Operation Procedures for Determining the Asphaltic Smoke after

Cyclohexane Extraction

Wrap the filter cartridge, after sampling and with constant weight, by 100~120 mesh nylon screen cloth (6.4) (note; do not cut the filter cartridge); and put it into the extraction tube of Soxhlet extractor (6.2); the height shall be lower than the extractor

Siphon area. Pour an appropriate amount of cyclohexane (5.1) to immerse the extractor siphon tube; add about another 40mL after siphoning; install the condenser;

turn on the electric heating bowl (6.3) to heat; and make the cyclohexane droplets in the extractor cool at a rate of 0.5~1 drop/s. After siphoning backflows for 8~10 times, the asphaltic smoke-cyclohexane solution in the receiving bottle is about 40mL; stop heating; cool off the receiving bottle; and transfer the extract of the receiving bottle to

100mL beaker with constant weight, (siphon the cyclohexane in the extraction tube into the receiving bottle, discard the filter cartridge); and wash the receiving bottle by cyclohexane (5.1) for three times, 5 mL each time. The washing solution is combined with the extract in the beaker; and the total volume is about 60mL. Cover the beaker by filter paper and evaporate naturally at room temperature and pressure. After the cyclohexane has evaporated completely, place the beaker in a desiccator for 24h and weigh it to a constant weight. Record the weight gain deltaWtot. of the beaker, (there shall be deltaWtot. ~deltaW1), accurate to 0.1mg. At the same time, take the same batch of filter cartridges for a blank test. When the blank test value is less than ±1mg, the correction value can be ignored.

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Additional Information

This Standard was proposed by Department of Science & Technology and Standard of National Environmental Protection Agency.

This Standard was drafted by Shanghai Municipal Environmental Monitoring Center.

Chief drafting staffs of this Standard: Ding Li, Jin Maoxia, and Feng Caiying.

This Standard is entrusted to China National Environmental Monitoring Center for