Particulate Control
1- For a given dust loading initially and two identical collectors in series, why is the overall collection efficiency for the second usually less than that of the first collector?

2- An industrial furnace burns No. 4 residual oil with a heating value of 135,000 Btu/gal. Based on the emission factors given in Table 5-4, is a particulate collector required to meet a state emission standard of 0.10 lb/106 Btu?

3-Two particulate collectors are in series. The fractional efficiency for size dp in the upstream device is 80 percent, and for the downstream device the efficiency is 60 percent. Find the overall removal efficiency for size dp.

4- What is the required minimum efficiency of an electrostatic precipitator used as the second collector, when it is preceded by a cyclone separator having an efficiency of 80% if the desired overall efficiency is 98 %?
5- A spreader stoker is used to burn coal containing 8 per cent ash. The flue gas from burning 1 lb of coal is 170 ft3. What is the maximum dust loading of PM in combustion gas in grains per cubic foot?