Chapter 75- Air Compression

Question 1

Compressed air tools

Answer 1

Are more more expensive than electrical tools

Question 2

In a centrifugal compressor the kinetic energy is converted to potential energy in the

Answer 2

Both volute casing and diffuser

Question 3

The compressor which would favour volume over pressure would be the

Answer 3

Centrifugal compressor

Question 4

Positive displacement compressors

Answer 4

Can be single stage with three cylinders

Question 5

Single stage reciprocating air compressors

Answer 5

Could have two cylinders

Question 6

Sliding vane compressors

Answer 6

Are positive displacement compressors

Question 7

A belt driven lubricator is very popular on a

Answer 7

Sliding vane unit

Question 8

Where pistons move in a cylinder it is necessary for the lubricant to provide

Answer 8

Sealing

Question 9

Higher gearing is commonly used on

Answer 9

Screw units

Question 10

A type of air compressor which draws in a charge of air, traps it, reduces its volume and then discharges it, is called a

Answer 10

Positive displacement compressor

Question 11

A type of compressor which imparts velocity to the air and then converts this velocity to pressure is the

Answer 11

A dynamic compressor

Question 12

The determining factor as to which type of compressor to use is

Answer 12

The maximum operating pressure required

Question 13

In a two stage air compressor the second stage is

Answer 13

Smaller than the first stage

Question 14

Positive displacement air compressors include

Answer 14

Sliding vane, rotary screw, rotary lobe

Question 15

Compressor unloaders

Answer 15

Could keep the suction valve open

Question 16

To reduce air temperature between stages we would use

Answer 16

An inter cooler

Question 17

An air compressor auxiliary which will decrease the power requirement is the

Answer 17

Intercooler

Question 18

Intercoolers

Answer 18

Should have a safety valve

Must have a drain

Question 19

Air receivers must have a

Answer 19

Safety valve

Question 20

When an inter cooler is used it should be equipped with a

Answer 20

Thermometer
Safety valve
Pressure gauge

Question 21

An after cooler which is equipped with a shut off valve between the after cooler and the receiver should be equipped with a

Answer 21

Safety valve

Question 22

Name three common adsorbents

Answer 22

Bauxite
Activated alumina
Silica-gel

Question 23

In order to regenerate the adsorbent when it becomes saturated with moisture it needs to be heated to about

Answer 23

150 degrees Celsius

Question 24

An air receiver pressure vessel specifications must conform to

Answer 24

ASME section VIII

Question 25

A start and stop compressor control should be set to operate at approximately ___________kpa pressure differential

Answer 25

100

Question 26

A method to control the air compressor output which makes use of an internal combustion engine or steam turbine is the

Answer 26

Variable speed contro

Question 27

The constant speed control method for an air compressor is usually driven by a

Answer 27

Electric motor

Question 28

Air compressors may have a number of system protective devices. Another word for those devices is

Answer 28

Interlocks

Question 29

Relative to a dry pipe fire system, an automatic air supply shall be connected so the proper pressure can be maintained in

Answer 29

National fire protection association code

Question 30

In order to have economical and trouble free operation of an air compressor, the _____________ must be maintained

Answer 30

Correct working temperature

Question 31

The cooling water for an air compressor should be turned on

Answer 31

Before starting the compressor

Question 32

Compressed air machinery would most like be used in

Answer 32

Coal mines