2. Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of __________ times the paddle diameter.
5. The thickness of heat transfer plates used in the plate type heat exchanger ranges from __________ mm, pressed in a single piece provided with grooves & corrugations.
6. The diameter of a propeller agitator used in agitation tank ranges from __________ percent of the tank diameter and its peripherial speed is normally 300 to 500 metres/minute.
7. Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower.
Options
A. Plate tower is perferred, if interstage cooling is required to remove heats of reaction or solution.
B. Plate tower is preferred over packed tower, if the operation involves liquids containing dispersed solids.
C. The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty.
D. In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes.
9. Which of the following is not a graphical method (but is an analytical method) for the calculation of theoretical number of stages in case of continuous binary distillation?
10. Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of __________ type.