3B2 Ch 8

Question 1

In a centrifugal compressor, the amount of velocity to pressure conversion through the impeller is a function of what?
Select one:

a.
The straightness of the volute blades

b.
The degree of curvature of the diffuser blades

c.
The straightness of the diffuser blades

d.
The size of the discharge pipe

e.
The degree of curvature of the impeller blades

Answer 1

e.
The degree of curvature of the impeller blades

Question 2

The spiral valve on a packaged industrial screw compressor varies the volume of compressed air produced by:
Select one:

a.
Regulating the amount of air to the unit according to demand

b.
Regulating the speed of the driver

c.
Regulating the amount of cooling water to the cooler

d.
Returning air to the suction line

e.
Bypassing the air dryer

Answer 2

d.
Returning air to the suction line

Question 3

The compression ratio is the ratio of:
Select one:

a.
Absolute discharge pressure to absolute inlet pressure

b.
Gauge discharge pressure to gauge inlet pressure

c.
The volume at the beginning of a compression stroke to the volume at the end

d.
The gauge inlet pressure to the absolute discharge pressure

e.
Piston diameter to piston stroke

Answer 3

c.
The volume at the beginning of a compression stroke to the volume at the end

Question 4

Axial flow compressors are similar to centrifugal air compressors in that they have which added advantage?
Select one:

a.
Being lower in mass

b.
Being a shorter machine

c.
Being corrosion and erosion free

d.
Being approximately 20% more efficient

e.
Solid forged rotor

Answer 4

a.
Being lower in mass