MCQOPTIONS
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MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer Operations knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The industry that extensively uses Scraped Surface Heat Exchangers is? |
| A. | Food industry |
| B. | Petrochemical industry |
| C. | Oil industry |
| D. | Steel Plants |
| Answer» B. Petrochemical industry | |
| 2. |
Evaporation of as fluid to complete dryness can never be performed in a Scraped Surface Heat Exchanger setup because? |
| A. | The blades will tear faster |
| B. | The statement is wrong, this operation can be carried out |
| C. | Vessel will have high fouling |
| D. | Agitators will burnout |
| Answer» C. Vessel will have high fouling | |
| 3. |
Why do we calculate rotary Reynolds Number and not use Seider-Tate equation? |
| A. | Because of no turbulence in the flow |
| B. | Because no correlations have yet been found for this setup |
| C. | Because the former equation involves moving fluid and not the rotating ones |
| D. | Two fluids are not involved |
| Answer» C. Because the former equation involves moving fluid and not the rotating ones | |
| 4. |
If the diameter of the rotating blades in 30mm, agitator speed is 20 RPM and the fluid in the vessel has density 990kg/m3 and viscosity 2.5 10-2 kg/ms. What is the value of Rotary Reynolds Number? |
| A. | 11.88 |
| B. | 12.88 |
| C. | 12.33 |
| D. | 11.55 |
| Answer» B. 12.88 | |
| 5. |
Which one of the following expression is correct for the rotary Reynolds Number in Scraped Surface HE? |
| A. | ( frac{D^2 N rho}{ mu} ) |
| B. | ( frac{DN rho}{ mu} ) |
| C. | ( frac{D^2 N mu}{ rho} ) |
| D. | ( frac{N rho}{ mu} ) |
| Answer» B. ( frac{DN rho}{ mu} ) | |
| 6. |
For a concentrating process, setting the setup_________ is the preferred arrangement. |
| A. | Vertically |
| B. | Horizontally |
| C. | Inclined |
| D. | Reclined |
| Answer» B. Horizontally | |
| 7. |
There are two types of Surface renewal heat exchangers, which one of the following is correct? |
| A. | Scraped and Wiped Surface |
| B. | Scraped and Swiped Surface |
| C. | Scraped and Polished Surface |
| D. | Scraped and Scratch Surface |
| Answer» B. Scraped and Swiped Surface | |
| 8. |
It is usually preferred to use wiped surface heat exchangers because of reduced wear and tear of the blades and surface. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 9. |
Scraped Surface Heat Exchanger that actually don t touch the surface are also known as _______ Surface Heat Exchanger. |
| A. | Scratched |
| B. | Wiped |
| C. | Scraped |
| D. | Swiped |
| Answer» C. Scraped | |
| 10. |
The number of blades is a Scraped Surface Heat Exchanger does not depend on one of the following factor, which one is it? |
| A. | Capital Cost |
| B. | Rotation speed |
| C. | Fouling Factor |
| D. | Viscosity |
| Answer» D. Viscosity | |
| 11. |
The maintenance cost of the Scraped Surface Heat Exchanger is usually low because of one of the following factor. What is it? |
| A. | It removes the fouling formed at the surface |
| B. | No motors are used |
| C. | No pumps are used |
| D. | High viscous fluids are used |
| Answer» B. No motors are used | |
| 12. |
Scraped Surface Heat Exchangers are used for fluids which are generally heat ________ |
| A. | Sensitive |
| B. | Insensitive |
| C. | Resistant |
| D. | Insulator |
| Answer» B. Insensitive | |
| 13. |
We use Scraped Surface Heat Exchangers when the fluid in operation is very viscous. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 14. |
What can Scraped Surface Heat Exchangers do? |
| A. | Adds turbulence to the core of the fluid |
| B. | Can handle large pressure drops |
| C. | Removes the layer of fluid at surface and mixes with bulk |
| D. | Use high pumping power |
| Answer» D. Use high pumping power | |