Chapter 6
1．A cyclone separator is operating in conditions where DCUT=10m. We are offered another cyclone that is of the same design, but all the dimensions are one-half as big as the present one. If we feed the same air stream(same total volumetric flow rate, same particle loading, same particle size distribution) to this new cyclone, what will the new value of Dcut be? The pressure drop, which is proportional to V will increase by a factor of 16!
2. The human nose and nasal passages remove particles from the air destined for our lungs. Consider it as a cyclone separator, with N=0.25; its average dimensions perpendicular to flow are 1cm′1cm, Assume that a typical breath is 1 litter, drawn in over a period of 1s. Estimate the cut diameter of the human nose for paricles.( The observed behavior of the nasal system is that few partiles larger than about 5m reach the lungs, so the calculation here is only approximately corret.)
3. We are passing a gas stream through a cyclone with DCUT=10m. We now must t reat twice as much gas in the same cyclone, so the average gas velocity will be increased by a factor of 2. We are told by the cyclone manufacturer that we shoule have no special troubles with re-entrainment of disturbance of the flow patterns if we double the flow rate. What will the cut diameter be at the new flow rate?
4.An ESP is treating a particle-laden air stream, collecting 95 percent of the particles. We now double the air flow rate, keeping the particle loading constant. What is the new percent recovery?
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