Do q3 Efficiencies and penetrations of a particulate control

Efficiencies and penetrations of a particulate control system with several devices in series. A stream of gas flowing at 3000 acfm has a particulate loading of 50 gr/ft^3 (grains/cubic foot). What is the allowable exit loading if 95% collection efficiency is required? What is the mass of particles collected, in kg/day? A coal with 6% ash and a heating value of 13,000 Btu/lb is burned in a new power plant. Assume that 30% of the ash falls out as bottom ash in the furnace. Calculate the efficiency of an ESP required to meet federal new source performance standards. The following data were obtained from a cascade impactor: Is the distribution log-normal? If so, estimate sigma_g and d_50.

Solution

The mean and s.d of a log normal distribution can be written in terms of the regular mean and s.d. as follows:

Use ln = log to base \"e\"

If Mean= a , s.d= b , then log normal mean x = ln (a*(1+ (b/a)^2)^0.5)

log normal s.d y = sqrt(ln(1+ (b/a)^2)

or x = ln (a) - y*y/2

Analysing the given data, the mean is 60=a and the s.d. is 43.205=b

A plot of size vs mass shows a skewed distbn to the right, characteristic of a log normal curve _ SO Log Normal

calculation shows y = 0.6464

x = ln60- y^2/2 = 3.885

I assume that d50 is the lognormal mean which from the data falls between 0-8 micron