200 m3/h hot gases from a smelting operation are scrubbed by using 4 m3 /h water in a cross flow gravity scrubber of 5 m height and 2m*2m cross sectional area . the average size of the spray droplets , formed by water spray nozzles uniformly located in a cross section of the scrubber , is 550 microns . the size of the particles in the gas is, uniformly , 1 micron. determine the efficiency of the unit density of the gases = qg = 0.0011 g/cm3 viscosity of the gases = mew = 0.02 cp