An electrostatic precipitator is to be used to clean 50 m3/s of a particulate-laden gas stream from a blast
furnace. The proposed design of the precipitator calls for three bus sections (fields) arranged in series. The inlet
particulate loading has been measured as 8.5 g/m3, and an outlet loading of 0.1 g/m3 must be achieved in order to
comply with provincial regulations. Each section consists of 12 grounded plates, 2.5 m high and 6 m long, spaced 0.25
m apart and the gas passes horizontally through the precipitator. Answer the following questions:
a. What is the minimum collection efficiency that will satisfy the regulation?
b. If the drift velocity for each section is 0.125 m/s, what is the collection efficiency of the proposed unit?
c. How many identical sections will have to be added (in series) to bring the proposed unit into compliance?
Assume that the added sections also have a drift velocity of 0.125 m/s.
d. If the proposed unit is limited to a maximum of three sections, how many plates (additional area) must be
added to each section to ensure compliance? Assume that the drift velocity is unaffected by the addition of
more plates.