Process Equipment and Plant Design Quiz 4

In packed absorption tower, onset of flooding usually occurs at a pressure drop of about _______ mm of water column per metre height of packing?

Minimum baffle spacing recommended in a shell and tube heat exchanger is equal to _______?

Movement of pipeline caused by thermal expansion is taken care by providing _____?

Nominal size of a pipe is an indication of its ________ diameter?

Maximum plate efficiency is achieved in case of _______ flow?

Normally, the length to diameter ratio of rotary dryers varies from 4 to 10 and for its economic operation; the number of transfer units (NTU) for such dryers varies from ?

Normal screwed fittings are used for pipes upto a diameter of ________ inches?

Of the pressure vessels, with same thickness but different diameters, which one withstands higher pressure ?

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

Normally, the plate thickness of the bottoms and roofs of vertically cylindrical storage vessels as compared to that of the cylindrical shell is_____?

Optimum economic pipe diameter for fluid flow is determined by the______?

Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter) ?

In sieve plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally _______ times the hole diameter to give the required hole area?

Longitudinal stress induced in a thin walled cylindrical storage vessel is ___________?

Length to diameter ratio of most rotary driers is in the range of______?

Low pressure steam (with saturation temperature between 105 to 120?C) is usually used in the vacuum evaporators, which normally employ a vacuum of about ________ mm Hg (referred to a 760 mm mercury barometer)?

In shell and tube heat exchangers, straight tie rods are used to__________?

Optimum reflux ratio in a continuous distillation column is determined by the___________?

It is not desirable to design a heat exchanger for LMTD correction factor, FT, of less than __________?

Log mean temperature difference in case of multi-pass shell and tube heat exchanger is always__________?

Le/D) for 90? elbow (medium radius) and 90?square elbow would be respectively around_____?

In the design of a paddle agitator, the ratio (paddle dia/tank dia) is normally taken as_____?

In which of the following evaporators, steam is fed inside the tube while the liquor is outside the tube ?

Mc Cable Thiele method used for finding theoretical stages in a distillation column assumes that the_______?

In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5-10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed _________ of the column diameter?

In the case of a shell and tube heat exchanger, the logarithmic mean temperature difference ________?

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?

Maximum acceptable total liquid gradient over a tray is about ________ mm?

Joint efficiency (J) for a seamless pipe is________?

Lug support is meant for supporting ________ vessels?

Larger depth of liquid on the trays of a distillation column__________?

Lap joints are preferred for plates having thickness ________ mm?

Minimum tube pitch recommended for shell and tube heat exchangers is about ________ times the outside diameter of the tube?

In the design of a bag filter, the gas temperature is an important consideration, as it affects the_____?

Large process vessels operating under extreme temperature and pressure conditions are normally clad/ lined with materials like stainless steel, aluminium, nickel & its alloys, copper & its alloys and titanium. The cladding thickness is generally about _______ percent of the total thickness?

Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than _______ kilolitres?

Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or _______ times the column diameter, whichever is lower?

In the downcomer of a distillation column, the minimum recommended residence time is about ________ seconds?

Overall distillation column efficiency for most of the refinery columns can be given by (for ? = 0.07 ? 1.4 cp and relative volatility < 4) (where ? = overall column efficiency, % ? = molal average viscosity of feed at average column temperature and pressure, cp ?p = pressure drop per tray, psi) ?

Liquid gradient over a tray can be minimised by_________?

In the allocated cap area, bubble caps are generally arranged on equilateral triangular pitch. Number of caps fixed on a plate is with a ___________?

Normally, the ratio of the total riser area to the tower cross sectional area (for bubble cap towers of diameter more than 3 ft) is around________?

Overall mass transfer co-efficient in case of absorption of __________ in water is based on the gas film co-efficient only, as the mass transfer process is gas film (phase) controlling ?

LMTD correction factor is used in heat exchanger design for______?

Maximum allowable vapour velocity in a bubble cap tower is determined by the ______?

Needle valves are generally not used for_____?

Maximum size of the raschig rings used in a packed tower is about ________ of the column diameter?

Liquid gradient over the tray results due to the_____?

Most of the storage vessels/tanks are made cylindrical, because of the fact that a cylinder __________?

In packed towers provided with saddle packing, liquid redistributors are positioned at every ________ times column diameter or 6 metres whichever is less?