- (A) Nu = (Re) (Pr) (Gz)
- (B) Nu = (Re) (Pr) (St)
- (C) Nu = (Re) (Pr)
- (D) Nu = (Pr) (St)
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- (A) Ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1
- (B) Filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period
- (C) Flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids
- (D) Dished bottom vessel has very high power consumption
- (A) When highly corrosive fluids are to be handled, the plate towers prove to be cheaper and easier to construct than packed tower
- (B) Packed towers are generally preferred over plate towers, if the liquids have a foaming tendency
- (C) The pressure drop through the packed towers is generally more than the pressure drop through plate towers designed for same duty
- (D) None of these
- (A) For all the cylindrical process vessels operating above atmospheric pressure, formed heads are used for closing the vessel
- (B) Fouling factor of river water is less than that of sea water
- (C) Risers provided in bubble cap trays in the distillation column facilitate the flow of both liquid and vapor
- (D) Both
- (A) Bubble cap trays though most expensive are the best in situations, where low vapour rates is to be handled and a positive liquid seal is essential at all flow rates
- (B) Murphree efficiency of all the three trays are nearly equal, however the peak efficiency is generally higher for sieve and valve trays than the bubble cap
- (C) Maintenance cost for valve and sieve trays are comparatively more than bubble cap tray due to their relatively complicated construction features
- (D) Valve trays have the highest turn down ratio (i.
- (E) the ratio of the highest to the lowest vapour flow rates) and thus provide the maximum flexible operating range
- (A) An increased weir height improves the tray efficiency at the cost of high plate pressure drop; optimum wear height being 40-90 mm for column pressure above atmospheric and 6-12 mm for vacuum columns
- (B) For segmental downcomers, the chord length is 60-80% of the column diameter. An initial value of downcomer area of 12% is taken in the design
- (C) Width of the calming section provided at the inlet and outlet sides of the plate is 75 mm for column diameter below 1.5 metres and 100 mm for larger diameter columns
- (D) Minimum recommended downcomer residence time for the disengagement of entrained vapour is the same for both foaming and non-foaming liquids, which is about 20 seconds
- (A) Safety valves are provided in heat exchangers for removal of non-condensable
- (B) Liquid metals and Dowtherm are used for very high temperature heating
- (C) In a shell and tube heat exchanger, high pressure fluid is generally routed through the tube
- (D) A loop seal or U-seal is provided in a vertical condenser sub-cooler to prevent quick draining of the condensate
- (A) Diameter of Horton sphere is normally 6 to 25 metres and it is supported by 6 to 12 nos. tubular or rolled section column
- (B) Thickness of spherical shell is half that of the cylindrical vessel under same operating pressure condition. Besides, the ratio of surface area to volume is less for sphere than any other shape; hence insulation required is less
- (C) Horton sphere is used for the storage of gases and volatile liquid at a moderate pressure of 1 to 10 kg/cm2
- (D) Horton sphere is used for the storage of liquid at sub-zero temperature at very high pressure upto 200 kg/cm2
- (A) Distillation under vacuum is a substitute for steam distillation
- (B) In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation
- (C) In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other
- (D) Flash distillation, differential distillation & steam distillation are all continuous distillation processes
- (A) 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F
- (B) In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity
- (C) In unsteady state heat conduction, heat flows in the direction of temperature rise
- (D) In heat transfer by forced convection, Grashoff number is very important
