Air Pollution Control 40920.8 Determine the efficiency of a cyclone of diameter 0.5 m, at a flow rate of
0.4 m3/s, and a gas temperature of 25°C. The inlet width is 0.13 m2 and the area of the
entrance is 0.04 m2. The particles have a diameter of 10 Fm and a density of 2 g/cm3.
20.9 An electrostatic precipitator has the following specifications: height = 7.5 m,
length = 5 m, number of passages = 3, plate spacing = 0.3 m. The flow rate is 18 m3/s
and the particle size is 0.35 Fm, and the particles have a drift velocity of 0.162 ds.
Calculate the expected efficiency.
20.10 For Problem 20.9 above, what would be the increase in e€liciency achieved
by doubling the length? by doubling the number of plates and reducing the flow rate
to 9 m3/s?
20.11 A copper smelter produces 500 tons of copper per day from ore that is
essentially CuS2. The sulfur dioxide produced in this process is trapped in a sulfuric.
acid plant that produces 98% by weight sulfuric acid, which has a specific gravity of
2.3. If 75% of the SO2 produced is trapped by the acid plant, how many liters of 98%
H2SO4 are produced each day?
20.12 There are 168 h in a week, so that one 24-h day is 14.3% of a week.
Therefore, you could decrease your personal electricity consumption by 14.3% by
doing without electricity for one 24-h period each week. Try this for a week. What
activities did you have to curtail or change? You can do this in three 8-h periods or
six 4-h periods, but they should be spread out during the day to encompass heavy-use
hours as well as light-use hours (do not just take three 8-h periods when you are asleep).
If a fossil fuel power plant is 42% thermally efficient (that is, 42% of the heat generated
is converted to electricity), what is your personal percent decrease in C02 emission?