Deck 48: Cooling Towers and Pumps

Question 1

The term ____ refers to the process of cooling the circulating condenser water by evaporating the tower water.

A) cyclic
B) adiabatic
C) isothermal
D) polytropic

Answer 1

B

Question 2

The purpose of the cooling tower bypass valve is to ____.

A) route debris away from the tower sump
B) prevent cavitation at the pump
C) provide makeup water to the tower sump
D) help maintain the correct water temperature to the condenser

Answer 2

D

Question 3

Two methods used to aid the evaporation rate of water in a forced or induced draft tower are ____.

A) vortexing and cavitation
B) spray pond and prevailing wind
C) float type valve and by-pass valve
D) splash and wetted-surface (or fill)

Answer 3

D

Question 4

A well-designed and installed cooling tower requires only a minimum of maintenance.

Question 5

The condenser water pump is the device that moves the water through the condenser and cooling tower circuit.

Question 6

Cooling towers are designed to reduce the entering water temperature to within ____°F of the air's wet-bulb temperature.

A) 3
B) 7
C) 14
D) 35

Question 7

The difference between the entering air wet-bulb temperature and the temperature of the water leaving the tower is called the ____________________.

Question 8

Natural draft towers and spray ponds are designed to produce a difference in water and air temperatures of ____°F.

A) 3
B) 5
C) 7
D) 10

Question 9

The heat that the cooling tower must reject from the water in the chiller is the cooling load of the conditioned area plus the heat of ____.

A) absorption
B) compression
C) vortexing
D) cavitation

Question 10

Distilled water is added to the cooling tower to make up for water lost during blowdown.

Question 11

Spray ponds on rooftops have made a comeback in the last few years because they cool the roof and reduce the solar load on the structure.

Question 12

If vortexing occurs, it is an indication that there is not enough air in the tower.

Question 13

When sizing a cooling tower, the tower is sized to handle the cooling load of the conditioned area plus about ____% for heat of compression.

A) 0
B) 15
C) 25
D) 35

Question 14

A blowdown system for a cooling tower ____.

A) reduces the concentration of sediment in the sump
B) provides extra draft for higher evaporation rate
C) promotes vortexing
D) provides a means for balancing the water flow

Question 15

A spray pond would be an example of a(n) ____________________ draft cooling application.

Question 16

Technician "A" says that a cooling tower can reduce the temperature of the water supplied to the condensers to a temperature equal to, but not less than, the wet-bulb temperature of the ambient air. Technician "B" says that a cooling tower's approach temperature is the temperature of the water returning from the water cooled condensers. Which of the following statements is correct?

A) Technician "A" is correct. Technician "B" is correct.
B) Technician "A" is correct. Technician "B" is incorrect.
C) Technician "A" is incorrect. Technician "B" is correct.
D) Technician "A" is incorrect. Technician "B" is incorrect.

Question 17

A new chemical-free water purification technology is used in cooling towers to ____.

A) avoid vortexing
B) balance the water flow
C) eliminate scale
D) All of the above.

Question 18

If the blower on a cooling tower breaks down on a hot day, the ____.

A) approach temperature will increase
B) water supplied to the condensers will be warmer
C) efficiency of the tower will increase
D) Both a and b.

Question 19

Two types of shaft seals used for centrifugal pumps are ____.

A) stuffing box and mechanical types
B) stuffing box and splash types
C) ceramic and splash types
D) ceramic and bellows types

Question 20

Natural draft cooling towers usually has an approach temperature of about ____________________°F because of relying only on the winds.

Question 21

Condenser water pumps are normally ____________________ pumps.

Question 22

Define parallel alignment.

Question 23

Define drift.

Question 24

Larger cooling towers generally use ____________________-type fans.

Question 25

Define angular alignment.

Question 26

What prevents the water in a cooling tower from freezing in cold weather?

Question 27

The water that leaves a cooling tower passes through a strainer. Why?

Question 28

The two air flow patterns for cooling towers are ____________________ and counterflow.

Question 29

____________________ allow the motor to soft start and to coast down without abruptly shutting the motor off.

Question 30

Describe vortexing.