大气污染控制工程试题2

This test is divided into two sections.SectionⅠcan be completed with the help of the textbooks and notebooks.Section Ⅱmust be finished by yourselves without the help of any material. All of the test should be finished in English.

The following data may be useful for your tests.

1. Molecular weight

air =29, toluene=92, acetone=58

2. Conversion factors

K=℃+273 1 feet=0.3048m 1cp=0.001kg/m·s 1atm=1.013×105Pa

3.The properties of air in the standard conditions (20*C, 1 atm)and other constants

air viscosity:μ=0.018cp

air density:ρ1.204kg/m3

acceleration of gravity :g=9.8m/s2

universal gas constant: R=8.31J/mol·K

Part A

Directions: You must give the definitions of the following terms, using simple and reasonable expressions. (2’×5)

1. air quality standard philosophy

2. adiabatic lapse rate

3. plume rise

4. drag coefficiency

5. prompt NO

2. How to explain air pollution effects on visibility?

3. What are the three alternatives for air pollution control?

4. Please explain the particles collection mechanisms of ESP.

5. How to Control VOCs?

6. What is the basic idea of wall collection device?

7. How does global warming take place?

8. Please explain the differences between the emission sources of SO x and the emission sources of NO x.

9. How do the temperature inversions produce, and what are the harmful effects of temperature inversions?

Part C

Directions: In Part C you will give the answers in detail according to the requirements of each question.(8’+8’+6’)

1. Please give the dervation of efficiency equation for block flow in gravity settlers.

4. In the following figure, the actual lapse rate is shown as a solid line, whereas the adiabatic lapse rate is shown as the dashed line. Which following description about the atmospheric stability is correct according to the figure. ( )

5. Which of the following meteorological conditions can cause high ground-level pollutant concentrations near the ground-level or low-level sources? ( )

A. unstable atmosphere

B. stable atmosphere

C. temperature inversion

D. low wind speed

What was the average particle concentration in this stack over the whole 50min of the test? ( )

A. 0.468g/m3

B. 0.500g/m3

C. 0.473g/m3

D. 1.420g/m3

E. 0.030g/m3

7. In the fixed models, pollutants only leave or enter through which section of the boxes? ( )

A. ABCD section

B. AEHD section

C.DCGH section

D.CBFG section

E. ABFE section

F.EFGH section