Ch. 12 Flashcards
(49 cards)
- A ___________ works on the principle of cool air contacting and removing heat from warm water.
a. shell and tube exchanger
b. circulating pump
c. cooling tower
d. evaporator
e. deaerator
c. cooling tower
- The hyperbolic cooling tower has the advantages of:
1) Low initial cost 2) Low power consumption 3) Long service life 4) Minimum maintenance
a. 1, 2, 3
b. 2, 3, 4
c. 1, 3, 4
d. 1, 2, 4
e. 1, 2, 3, 4
b. 2, 3, 4
- The cooling tower design in which the fan is least likely to ice up is:
a. Hyperbolic
b. Induced draft
c. Forced draft
d. Counterflow
e. Balance draft
b. Induced draft
- The cooling tower design in which the noise level from the fan is likely to be the lowest is:
a. Hyperbolic
b. Induced draft
c. Forced draft
d. Counterflow
e. Balance draft
b. Induced draft
- The double pipe heat exchanger belongs to the ___________ category.
a. regenerative
b. bent pipe
c. double tube
d. jacketed pipe
e. recuperative
e. recuperative
- The concentric pipe heat exchanger is suitable for high pressure service because ______________________.
a. the metal selected is stainless steel
b. the tubes, etc are small in dimension
c. the tubes are seamless construction
d. the unit is ASME stamped
e. None of the above
b. the tubes, etc are small in dimension
- The double pipe heat exchanger is a _______________ flow design.
a. concurrent
b. high differential temperature
c. high differential pressure
d. countercurrent
e. low differential temperature
d. countercurrent
- Concentric pipe heat exchanger fins can be attached by ________________.
a. mechanical insertion
b. casting
c. brazing
d. None of the above
e. All of the above
a. mechanical insertion
- The disadvantages of hairpin heat exchangers are:
1) Small heat transfer surface area 2) Not a flexible design 3) Cleaning is expensive 4) Each hairpin introduces more leak points 5) Non-standardized parts
a. 1, 3, 4
b. 1, 2, 3
c. 3, 4, 5
d. 1, 4, 5
e. 2, 4, 5
a. 1, 3, 4
- Which of the following is a disadvantage of a U-shaped shell and tube heat exchanger ____________________.
a. tubes are bent to a minimum radius
b. outer tubes are easily replaced
c. only one tube sheet
d. no differential expansion
e. good for high temperatures only
c. only one tube sheet
- U shaped shell and tube heat exchangers are not known for ______________________.
a. high heat transfer rates
b. high temperatures
c. high pressure
d. high differential expansion
e. All of the above
d. high differential expansion
- Fixed tube sheet shell and tube heat exchangers have ________________.
a. tube sheets that are contained with in the shell
b. little access for cleaning
c. tubes that are hard to plug
d. tube sheets not welded to the shell
e. None of the above
e. None of the above
- Fixed tube sheet chemical cleaning is used to clean ________________.
a. the inside of the tubes
b. the outside of the tubes
c. only the tubesheets
d. All of the above
e. None of the above
b. the outside of the tubes
- The floating tube sheet in the design allows for the _____________.
a. tube bundles to be easily removed
b. tube bundles to be easily repaired
c. different designs for different applications
d. different rates of expansion
e. use of different pressures and temperatures
d. different rates of expansion
- Reboilers are _________________________________.
a. an exchanger with process fluids on the tube inside
b. a boiler with steam on the outside of the tubes
c. an exchanger with steam inside the tubes
d. an exchanger that only reheats fluids to drive off vapours
e. a boiler that produces steam to heat vapours
c. an exchanger with steam inside the tubes
- What are the advantages of a Kettle type reboiler:
1) Provides flexibility 2) Rapid steamer 3) Gravity circulation 4) Easily accessible 5) Smaller size
a. 1, 2, 3
b. 2, 3, 5
c. 3, 4, 5
d. 1, 4, 5
e. 1, 3, 4
e. 1, 3, 4
- Horizontal thermosyphon reboilers require _________________.
a. a large vapor space
b. a small vapour space
c. a flooded shell
d. lots of heat transfer tubes
e. placement equal to the liquid level in the tower
c. a flooded shell
- Vertical thermosyphon reboiler often has _____________________.
a. heated liquid on the tube side
b. positioning next to a horizontal tower
c. steam on the tube side
d. liquid on the shell side
e. All of the above
a. heated liquid on the tube side
- In a horizontal thermosyphon reboiler, heat is controlled by _____________________________________.
a. adding more steam to the vessel
b. raising the vapour pressure on the shell
c. reducing the vapour pressure on the shell
d. raising the levels on the shell side
e. by varying the condensate level in the tube side
e. by varying the condensate level in the tube side
- Plate heat exchangers (PHE’s) use what to separate the two mediums a/an _______________________________.
a. rubber gaskets
b. different flow patterns
c. the plate corrugations
d. inlet and outlet piping
e. alternate plates
e. alternate plates
- Maximum cooling in PHE’s is maintained by _______________.
a. corrugating the plates
b. inlets and outlets at the plate corners
c. counter flowing the two streams
d. the thickness of the gaskets
e. thinness of the steel plates
b. inlets and outlets at the plate corners
- High heat transfer coefficients are maintained by ________________.
a. the use of numerous plates
b. the use of stainless steel
c. thinness of the gaskets
d. close spacing of the plates
e. All of the above
d. close spacing of the plates
- The use of compression bolts on PHE’s is to ________________.
a. tighten end plates
b. seal gaskets
c. compress the plate pack
d. decrease flow channel size
e. All of the above
e. All of the above
- Advantages of PHE’s include:
1) A rapid start up 2) Leakage easily detected 3) Enables use of low flow rates for erosion 4) Can cool toxic materials 5) Minimal heat loss
a. 1, 3, 4
b. 1, 2, 5
c. 2, 3, 4
d. 3, 4, 5
e. 1, 3, 5
e. 1, 3, 5
