• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/17

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

17 Cards in this Set

  • Front
  • Back

The most common type of mechanical draft cooling tower is:


1) An induced draft type


2) A dry type


3) A forced draft type


4) A wet type


5) A combination wet dry type

An induced draft type

Cooling towers:


1. Remove the heat from the condensate


2. Should use water treatment


3. Prevent thermal pollution of rivers and lakes


4. Cannot be used during winter periods


5. Remove the sensible heat of the steam in the condenser


1) 1, 3, 4


2) 1, 2, 3


3) 1, 3, 4, 5


4) 3, 4, 5


5) 2, 3

2, 3

Compared to a cross flow tower, a counter flow tower:


1) Is not as tall


2) Has a lower pressure drop


3) Has much less capacity


4) Requires less floor space


5) Requires less fan power

Requires less floor space

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


1) 15%


2) 5%


3) 2%


4) 10%


5) 3.5%

5%

The component of wood that is leached away reducing the ability of the wood to resist decay is the:


1) Leaves


2) Natural extractives


3) Bark


4) Lignin


5) Cellulose

Natural extractives

Cooling towers:


1) May contribute to the pollution problem


2) Need only be operated in the summer months


3) Remove heat from the condensate


4) Require fans


5) Do not require any maintenance

May contribute to the pollution problem

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


1) 1, 2, 3


2) 2, 3, 4


3) 1, 2, 4


4) 1, 3, 4


5) 1, 2, 3, 4

4) 1, 3, 4

Cooling towers:


1) Reduce flue gas temperatures


2) Cannot be used during winter periods


3) Are used with steam turbines only


4) Remove the heat from the condensate


5) Prevent thermal pollution of rivers and lakes

Prevent thermal pollution of rivers and lakes

You are replacing the cooling tower fan motor bearings because:


1) The gear reducer pinion shaft was misaligned


2) The motor was running single phase


3) Windings in the motor were faulty


4) The rotor was rubbing the stator


5) A noise that sounded like a bad bearing was heard

The rotor was rubbing the stator

Advantages of ID cooling towers over FD cooling towers include:


1. Accessibility of the fan for maintenance


2. Little chance of icing up in the winter


3. Minimum noise


4. A greater ability to cool the water


5. Ability to recycle the vapor, laden air


1) 3, 4, 5


2) 1, 3, 5


3) 1, 2, 3


4) 2, 3, 5


5) 2, 3, 4

5) 2, 3, 4

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


1) +27ºC


2) -0.5ºC


3) +20ºC


4) +5ºC


5) +0.5ºC

1) +27ºC

The principle cause of steel corrosion in cooling towers is:


1) Dissolved carbon dioxide


2) Dissolved oxygen


3) High pH


4) Low pH


5) Dissolved hydrogen

Dissolved oxygen

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


1) Require a windbreak


2) Where relative humidity is high


3) Where wind is relatively constant


4) Must not be in direct sunlight


5) Where a large body of water is nearby

Where wind is relatively constant

Natural draft cooling towers are divided into:


1) Closed and semi closed types


2) Filled and unfilled types


3) Atmospheric and chimney type


4) Dry and wet types


5) Open and filled types

Atmospheric and chimney type

The main scale forming substance in cooling water towers is:


1) Calcium carbonate


2) Calcium bicarbonate


3) Sodium sulphite


4) Sodium Phosphate


5) Potassium hydroxide

Calcium carbonate

To prevent cooling tower basin water from freezing during cold weather, many units are equipped with:


1) Warming tapes


2) Electric basin heaters


3) Ethylene glycol antifreeze systems


4) Ice defrosters


5) Propane burners

Electric basin heaters

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


1) Counter flow induced unit


2) Cross flow unit


3) Forced draft unit


4) Natural draft unit


5) Venturi unit

Venturi unit