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This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer knowledge and support exam preparation. Choose a topic below to get started.
1. |
What is the direction of flow in the centre tubes and wall-side tubes of a long tube falling film evaporator? |
A. | Both downwards |
B. | Both upwards |
C. | Downward and upward respectively |
D. | Upward and downward respectively |
Answer» B. Both upwards | |
2. |
The following are few demerits of using short tube vertical evaporators, select the incorrect one. |
A. | Long tubes efficiently evaporate and hence recirculation is hardly required |
B. | Corrosive fluids cannot be used as it increases cleaning cost |
C. | Large head room requirement |
D. | Very low heat transfer coefficients with thick fluids |
Answer» B. Corrosive fluids cannot be used as it increases cleaning cost | |
3. |
Which one of the following is not an advantage of Long tube evaporators? |
A. | Good heat transfer coefficients at low temperature gradients |
B. | Low head space required |
C. | Thin fluids have very large product economy |
D. | Relatively inexpensive to manufacture |
Answer» C. Thin fluids have very large product economy | |
4. |
Which one of the following is not a property of long tube evaporators? |
A. | It uses recirculation frequently |
B. | It has a down-comer |
C. | Has very long tubes |
D. | Uses natural convection |
Answer» C. Has very long tubes | |
5. |
While using Long tube evaporators, the desired concentration is usually not achieved in single flow. |
A. | True |
B. | False |
Answer» B. False | |
6. |
Long tube evaporators find their use in which one of the following most commonly? |
A. | Feedstock concentration |
B. | Food industries |
C. | Pharmaceuticals |
D. | Acid concentration |
Answer» C. Pharmaceuticals | |
7. |
The heating medium in the Long tube evaporator is usually _______ |
A. | Gas at temperature just above 130℃ |
B. | Steam |
C. | Gas at temperature just below 100℃ |
D. | Gas at very high temperatures |
Answer» C. Gas at temperature just below 100℃ | |
8. |
What is the average tube length of long tube evaporators? |
A. | 4-10ft |
B. | 4-10m |
C. | 1-2ft |
D. | More than 10m |
Answer» C. 1-2ft | |
9. |
Long tube evaporators are usually ______ evaporators. |
A. | Natural convection |
B. | Forced convection |
C. | Nucleate boiling |
D. | Radiation heated |
Answer» B. Forced convection | |
10. |
Long tube evaporators can be classified as rising or climbing film. |
A. | True |
B. | False |
Answer» B. False | |