PROCESS EQUIPMENT AND PLANT DESIGN 2.1

In a shell and tube heat exchanger, tube side __________ of the mass velocity.

• heat transfer co-efficient is proportional to 0.8th power

• pressure drop is proportional to the square

• both 'a' & 'b'

• neither 'a' nor 'b'

The optimum size ratio for two mixed reactors in series depends on the kinetics of the reaction and the conversion level. For reaction orders more than one, the

• equal sized reactors are the best

• smaller reactor should come first

• larger reactor should come first

• none of these

Pick out the wrong statement.

• Safety valves are provided in heat exchangers for removal of non-condensable

• Liquid metals and dowtherm are used for very high temperature heating

• In a shell and tube heat exchanger, high pressure fluid is generally routed through the tube

• A loop seal or U-seal is provided in a vertical condenser sub-cooler to prevent quick draining of the condensate

A head comprises of straight flange section, corner torus, section and central dished section. Crown radius and knuckle radius in a head is related respectively to the

• central dished section and corner torus section

• corner torus section and central dished section

• central dished section and straight flange section

• straight flange section and corner torus section

With increase in gas flow rate to fabric surface area ratio (Nm3/hr/m2 fabric surface area), the size & the cost of a bag filter

• increases

• decreases

• remain unaffected

• none of these

Needle valves are generally not used for

• very large diameter pipes

• high pressure throttling service

• very accurate flow control

• smaller sizes of pipe

Which of the following is used to set the diameter of the distillation column ?

• Number of theoretical plates

• Static submergence

• Allowable vapour velocity

• Length of straight rectangular weir on cross-flow tray

Ponchon Savarit method is based on the use of enthalpy concentration diagram, which contains the bubble point curve (saturated liquid curve), dew point curve (saturated vapour curve) and equilibrium tie lines. As compared to McCabe-Thiele's method, this method

• more accurate in finding the number of equilibrium stages

• accounts for the enthalpy changes in the process

• facilitates direct calculation of heat load on reboiler & condenser from, the diagram used in this method

• all 'a', 'b' & 'c'

Number of evaporators which can be used in service in a multiple effect evaporation system is limited by the

• practical limit reached, due to low heat transfer rate because of inadequate temperature difference

• economic limit reached, when the plant cost exceeds the saving of steam

• both (a) & (b)

• neither (a) nor (b)

Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the

• flow rates of each fluid

• type and size of packing

• concentration of each fluid

• all a, b & c