A. Is economical in operation
B. Employs high velocity, high heat transfer rate and less heating surface requirement
C. Employs a centrifugal pump placed between external downtake from vapor drum and inlet to
tube bundle
D. Both B. & C.
Related Mcqs:
- Tubes are fixed to the tube sheet (a thick circular metallic plate) by the method of tube rolling and brazing (non-removable) or ferrule connection (removable). Thickness of the tube, sheet is normally ____________ the outside diameter of the tube but in no case it should be less than 22 mm (7/8″)?
A. Half
B. Three fourth
C. Equal to
D. 1.5 times - Pick out the wrong statement pertaining to the design of a long tube vertical evaporator ?
A. Tube dia is 3-6 cms, while tube length in 3-6 metres
B. Steam is fed to the shell, whereas the liquor is filled inside the tube
C. Liquor level is maintained at 1/3rd to 1/2 of the height of the tube
D. None of these - ________________ liquor is best handled in a long tube vertical evaporator ?
A. Foamy
B. Scaling
C. Viscous
D. Salting - In a vertical short tube evaporator (Calandria type), the ______________________?
A. Tube dia of 2.5-7.5 cms, tube length of 75-200 cms and cylindrical drum dia of 1-6 metres are
normally used
B. Area of central downtake is equal to 40 to 100% of total cross-sectional area of the
surrounding tube
C. Liquor is inside the tube while the steam is outside the tube
D. All A., B. & C. - In most of the shell and tube heat exchangers, the tube pitch is generally ______________ the tube diameter?
A. Less than
B. 1.25-1.50 times
C. 2.5 times
D. one-fourth of - In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate)0.8. This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to____________________?
A. ∞
B. 1
C. 20.8
D. 2 - Minimum tube pitch recommended for shell and tube heat exchangers is about _______________ times the outside diameter of the tube?
A. 1.25
B. 1.75
C. 2.5
D. 3.5 - Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger________________?
A. Permits the use of less tubes in a given shell diameter
B. Facilitates comparatively easier external cleaning because of large clearance
C. Permits the use of more tubes in a given shell diameter
D. Both B. and C. - The ratio of down take area to cross-sectional area of the tube, for calandria type evaporator ranges from_________________?
A. 0.5 to 1
B. 1 to 1.5
C. 1.5 to 2
D. 2 to 2.5 - Tube height in a calandria type evaporator is normally less than _______________ metres?
A. 1
B. 2
C. 3.5
D. 5.5
