PPEQ 6002 - Cooling Towers (Chp 21)

Question 1

Two types of cooling towers are:

A) Mechanical and natural draft
B) Dry and wet
C) Concrete and steel base
D) Chandler and MacDonnell
E) Flooded and vapour

Answer 1

A) Mechanical and natural draft

Question 2

What is the difference between a refrigeration system evaporative condenser (Chap 19) and a cooling tower?

A) Water is recirculated through the cooling tower
B) Refrigerant is cooled by the cooling tower, water by the evaporative condenser
C) Water leaving the evaporative condenser is cooler
D) Water is cooled by the cooling tower, refrigerant by the evaporative condenser
E) The evaporative condenser uses drift eliminators

Answer 2

D) Water is cooled by the cooling tower, refrigerant by the evaporative condenser

Question 3

Natural draft cooling towers operate most effectively in large open spaces and:

A) Where a large body of water is nearby
B) Require a windbreak
C) Where the relative humidity is high
D) Where the wind is relatively constant
E) Must not be in direct sunlight

Answer 3

D) Where the wind is relatively constant

Question 4

Compared to a crossflow tower, a counterflow tower:

A) Has much less capacity
B) Has a lower pressure drop
C) Requires less floor space
D) Is not as tall
E) Requires less fan power

Answer 4

A) Has much less capacity

Question 5

A cooling tower which requires neither fan nor fill is the:

A) Venturi unit
B) Counter flow induced unit
C) Cross flow unit
D) Forced draft unit
E) Natural draft unit

Answer 5

A) Venturi unit

Question 6

A valve that prevents water flow over the fill of a tower during cold weather should not be closed until the temperature reaches:

A) 27 degrees C
B) 20 degrees C
C) - 0.5 degrees C
D) 5 degrees C
E) 0.5 degrees C

Answer 6

A) 27 degrees C

Question 7

High discharge water temperature from the cooling tower could be caused by:

A) Low dry bulb air temperature
B) Low wet bulb air temperature
C) High wet bulb air temperature
D) Fine water spray in the tower
E) Low concentration of solids in the water

Answer 7

C) High wet bulb air temperature

Question 8

Heat is removed from the water in a cooling tower by:

A) Bernoulli’s principle
B) Fans
C) A refrigerant
D) Evaporation
E) Pumps

Answer 8

D) Evaporation

Question 9

The rate of heat transfer in any cooling tower system depends on the:

1. Relative velocity of both air and water during contact
2. Volume of water in contact with the air
3. Length of contact time between the air and water
4. Difference between the inlet water temperature and the inlet air wet bulb temperature

A) 1, 2, 4
B) 1, 3, 4
C) 1, 2, 3
D) 2, 3, 4
E) 1, 2, 3, 4

Answer 9

B) 1, 3, 4

Question 10

The average amount of water volume which evaporates from a cooling tower is:

A) 3.5%
B) 2%
C) 15%
D) 5%
E) 10%

Answer 10

D) 5%

Question 11

The correct choice to manage algae or microbiological problems in cooling towers:

A) Drain the cooling tower and refill with fresh clean water
B) Increase the temperature to kill off the biological contaminants
C) Consult a water treatment specialist
D) Acid clean the cooling tower
E) Decrease the circulation rate through the cooling tower

Answer 11

C) Consult a water treatment specialist