Environmental Engineering FOURTH EDITION

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Chapter 20 Air Pollution Control Limiting emissions into the air is both technically difficult and expensive. However, since rai ...

386 ENVIRONMENTK ENGINEERING Figure 20-1. Points of possible air pollution control. (exhaust) is so difficult to trap and treat. ...

Air Pollution Control 387 Cooled aas Hot Cool Hot gas dilution gas gas Dilution Cooled gas Heat exchanger -1, Cooling - water (r ...

388 ENVIRONMENTAL, ENGINEEFUNG Escaped collection Inflow or feed Collection 0 device Collected or recovered + Figure 20-3. Diagr ...

Air Pollution Control 389 Cyclones The cyclone is a popular, economical, and effective means of controlling particulates. Cyclon ...

390 ENVIRONMENTAL ENGINEERING Figure Particulate discharge 20-5. Cyclone. (Courtesy of the American Lung Association.) Particle- ...

Air Pollution Control 391 where m = radial velocity (in ds), ps = density of particle (in kg/m3), p = density of air (in kg/m3), ...

392 ENVIRONMENTAL ENGINEERING Table 20-1. Values of K for Calculating Cyclone Pressure Drop Cyclone diameter (in.) K 29 16 8 4 1 ...

Air Pollution Control 393 EXAMPLE 20.1. A cyclone has an inlet width of 10 cm and four effective turns (N = 4). The gas temperat ...

394 ENVIRONMEWALENGINEEFSNG used in industrial applications, although they may be sensitive to high temperatures and humidity. T ...

Air Pollution Control 395 : .p. Clean gas out Spray riser Water jets Tangential inlet for dirty gas Water in Flushing jets, dire ...

396 ENVIRONMENTAL ENGNERDJG Although wet scrubbers are very efficient, and can trap gaseous pollutants as well as very fine part ...

Air Pollution Control 397 The collection efficiency of an electrostatic precipitator may be estimated by an empirical equation - ...

398 ENVIRONMENTAL ENGINEERING Figure 20-11. Effectiveness of electrostatic precipitators on a coal-fired electric generating pla ...

Air Pollution Control 399 HEPA Filters Very hazardous or toxic particulate matter of diameter less than 1 bm must sometimes be c ...

400 ENVIRONMENTAL ENGMERING Burner ports Burner piping Dirty gas inlet Figure 20-14. Incinerator for controlling gaseous polluta ...

Air Pollution Control 40 1 L Fuel & air - 1500°F Temp. r - Clean gas Dirty gas - Incineration Catalyst Fuel & air Clean ...

402 ENVlRONMENTALENGINEEIUNG Reheat SQ from fossil-fuel burning off-gas was first controlled by trapping as calcium sulfate in a ...

Air Pollution Control 403 SO2 may also be removed from flue gas by dissolution in an aqueous solution of sodium citrate by the r ...