5HB - October 1999
Part A (20 x 2 = 40 Marks)
Part B (5 x 12 = 60 Marks)
(ii) Critically analyze the differential and cumulative methods of analysis to determine the average particle size
(b) (i) What are the various types of industrial screens and how they are employed?
(ii) Explain the principle of electrostatic precipitation in gas cleaning
(b) A certain set of crushing rolls has rolls of 100 cm diameter by 38 cm width face. They are set so that the crushing surfaces are 1.25 cm apart at the narrowest point. The manufacturer recommends that they may be run at 50 to 100 rpm. They are to crush a rock having a specific gravity of 2.35, and the angle of nip is 30o. What are the maximum permissible size of the feed and the maximum actual capacity in tons per hour, if the actual capacity is 12 percent of the theoretical?
(ii) Quartz particles (density = 2650 kg/m3) are settling in water at room temperature. What will be the maximum particle diameter so that Stoke's law can hold good in this case. Viscosity of water = 1004 x 10-6 kg/(m.sec)
(b) Write the principles and applications of flotation. Explain any one of the commercial flotation equipment with the help of a neat sketch
(ii) Discuss any one filtration equipment with the help of a neat sketch
(b) Explain the principle of centrifugal filtration. Derive an expression for calculating specific cake resistance for incompressible sludges from the basic fundamentals
(ii) Write short notes on the following:
(1) Scale up in agitator design
(2) Flow pattern in agitation vessel with turbine impeller
(b) Discuss the following:
(i) Approximate dimensions of a turbine impeller and baffles used in a batch reactor based on reactor diameter
(ii) Power required for impeller mixers.