Page 295 - Materials Chemistry, Second Edition

CAT3525_C09.qxd 2/8/2005 10:11 AM Page 266
266 Waste Management Practices: Municipal, Hazardous, and Industrial

Cleaning Collecting

Clean
gas

Bags
supported on
frames

Dirty
gas

FIGURE 9.11 Schematic of a baghouse for particulate removal. (From Williams, 1998. Reproduced with kind
permission of John Wiley & Sons, Inc.)

TABLE 9.5
Baghouse Fabric Ratings
Recommended Chemical Resistance
Maximum
Fabric Temperature, (°C) Acid Alkali
Cotton 81 Poor Fair
Wool 103 Good Poor
Nylon 103 Good Poor
Dacron 134 Excellent Good
Glass 285 Excellent Excellent

Source: U.S. EPA, Air Pollution Engineering Manual, 2nd ed., 1973.

EXAMPLE 9.3

A baghouse holds a total of 50 bags for particulate removal from a mass-burn incinerator unit. A
single bag is cylindrical in shape and measures 25 cm diameter and 6 m in length. What is the fil-
tering area of the bag?
3
If the baghouse unit (50 bags) is to treat 15,000 m /h of flue gas, calculate the effective filtration
velocity in meters per minute and the mass of particles collected daily if the inlet loading is 120 g/m 3
and the unit operates at 99.99 % collection efficiency. Note that 1 kg of collected residue ~ 3150 g.