Compressor 1

Question 1

What are the 2 main categories of stew compressors

Answer 1

Oil flooded wet
Oil free dry

Question 2

Which rotor is the driver on a screw compressor

Answer 2

The main

Question 3

What determines the capacity of a screw compressor

Answer 3

Rotor length , diameter, lobe flute design and speed

Question 4

What function does the oil in an oil flooded screw compressor serve

Answer 4

Dissipate some of the heat due to compression seal the gaps between the rotor and casing to prevent leaking and lubricants the bearings and gear box and reduce the noise level

Question 5

Which style of screw compressor has two meshing star shaped rotors and central rotor

Answer 5

Mono screw

Question 6

Which compressor does the air enter after leaving the oil flooded compressor

Answer 6

Separate

Question 7

In exceedingly dusty conditions a what may be used in conjunction with a paper element filter to remove particles from the incoming air

Answer 7

Pre filter

Question 8

What is the purpose of the minimum pressure

Answer 8

To build a minimum pressure inside the separator to get the oil flowing on start up

Question 9

Which valve operates like the thermostat in a motor vehicle

Answer 9

Thermal mixing valve

Question 10

What is a screw compressor’s simplest type of control system

Answer 10

Online
Offline

Question 11

What control system allows the compressor to produce only the amount of air required by the system

Answer 11

Modulation control

Question 12

What do turn valves poppet valve and slide valves control in screw compressor

Answer 12

Displacement

Question 13

Vfd acronym for

Answer 13

Variable frequency drive

Question 14

When proper maintenance of the air end of a screw compressor is performed how many hours in between major overhaul can the compressor experience

Answer 14

80000-100000 hours

Question 15

What kind of oils are preferred for use in screw compressors because of the high temperature and continuous operation

Answer 15

Synthetic oils

Question 16

Which vale is much like the thermometer in an engine’s cooling system

Answer 16

Thermal mixing valve

Question 17

What could result in a compressor when there is a stuck blowdown valve

Answer 17

Low air delivery

Question 18

What type of compressor requires the vanes to be made from a special material with a low coefficient of friction such as Teflon or graphite

Answer 18

Dry vane oil free. Driving

Question 19

What type of compressor is flooded with oil all the time it is running

Answer 19

Wet vane

Question 20

How do vane compressor systems often eliminate the need for an air receiver

Answer 20

By using an inlet throttling control system

Question 21

What is the only major moving part in a sling vane compressor

Answer 21

Rotor assembly

Question 22

What does it mean for a compressor to have a built in pressure ratio

Answer 22

Pressure ratio in not adjustable as are reciprocating compressor

Question 23

Which component contains the inlet and outlet ports in a wet sliding vane compressor

Answer 23

Stator

Question 24

Which valve may be used to unload the compressor for ease of starting

Answer 24

Safety relief valve

Question 25

Which valve is used to reduce blade instability

Answer 25

Vacuum valve

Question 26

What is done to the end covers to ensure correct reassembly

Answer 26

Match mark

Question 27

How is the operation of the control system set at any specific pressure

Answer 27

Spring setting on the servo valve

Question 28

How does the gas enter and exit the liquid ring compressor

Answer 28

Cones or ports on port plates

Question 29

Which component throws the liquid inside the casing outward against the elliptical casing resulting in the formation of the liquid ring

Answer 29

Impeller vanes

Question 30

Which auxiliary component can be used to allow the re use of the seal water

Answer 30

Heat exchanger

Question 31

What is the minimum recommended replacement interval for stuffing box packing in a liquid ring compressor

Answer 31

Yearly

Question 32

How much grease should you pack into a bearing cap when re packing a bearing housings

Answer 32

1/3to1/4 full

Question 33

What must be removed be from the rotor assembly before mounting it in a press

Answer 33

Taper pins and set screws

Question 34

What tool can be used to to indicate the amount of wear on the impeller cone

Answer 34

Feeler gauge

Question 35

List the six types of bearings found in lobe blowers

Answer 35

Single row blower Double row blower Deep grove ball Angular contact Spherical roller Cylindrical roller

Question 36

Which components are machined to contain the bearing housing

Answer 36

End plates

Question 37

What are two common types of timing gears found in lobe blowers

Answer 37

Spur Helical

Question 38

Which types of lobe blowers would usually have a pressurized lubrication system

Answer 38

Large lobe blowers and those in vacuum service

Question 39

Where should the relief valve be located

Answer 39

Near the discharge

Question 40

What is a likely cause of scuff marks and abrasion along the length of the rotors and casing

Answer 40

Foreign material passing through the blower

Question 41

What could cause knocking in an operating lobe blowers

Answer 41

Pipe strain

Question 42

Which clearance is normally set at factory and rarely needs adjustment

Answer 42

Tip

Question 43

What are the two major classification of dynamic compressors

Answer 43

Centrifugal Axial

Question 44

Which compressor casing style allows easy removal of the upper section

Answer 44

Horizontally split

Question 45

What style of impeller allows one to achieve higher pressure ratios

Answer 45

Closed

Question 46

Which device is responsible for controlling compressor output and increasing efficiency

Answer 46

Inlet guide vane

Question 47

What does a balance piston minimize in a compressor

Answer 47

Thrust loading

Question 48

On which end of the compressor would the balance drum be located

Answer 48

Discharge end

Question 49

Which type of blade converts gas velocity to pressure

Answer 49

Stator blades

Question 50

Since the pressure rise per stage is small what is required to achieve a significant pressure increase across an axial flow compressor

Answer 50

Multi staging

Question 51

As the pressure increases through the compressor how does the volume and area is the blades change

Answer 51

Both decrease

Question 52

What are fir tree dovetail and bulb type examples of in a compressor

Answer 52

Blade roots

Question 53

Why are opposing gas flows used in a compressor

Answer 53

To decrease thrust

Question 54

Which component in an axial compressor is prone to fouling

Answer 54

Stator blades

Question 55

Between which two points in a dynamic compressor performance graph is the range of stability located

Answer 55

Surge and stonewall

Question 56

What is another term for stonewalling

Answer 56

Choked flow

Question 57

What is the function of the shroud on a compressor blade arrangement

Answer 57

Provide support for the longer blades and gas seal between rotating and stationary parts

Question 58

What does stage consist of in axial flow compressor

Answer 58

Set of stationary blades and a set of rotating blades

Question 59

What can be done to increase the efficiency of a single stage compressor

Answer 59

Diffuser vanes are fitted inside the housing allows you to aachieve a slightly higher compression ratio increasing the speed also increasing the volume

Question 60

What type of gases are liquid ring compressors able to handles

Answer 60

Saturated explosive dirty abrasive and process applications involving suspended solids

Question 61

What is slip as it pertains to lobe blowers

Answer 61

Leakage of higher pressure discharge air back through the blower towards the inlet

Question 62

What is the advantage of the helical lobe blowers over the two lobe blower

Answer 62

Increased pressure and smoother air delivery

Question 63

How is compressor capacity determined on a vane compressor

Answer 63

The volume of air between two sets of valves at maximum volume multiplied by number of vanes multiplied by speed of rotor

Question 64

Where would you find the servi valve in a sliding vane compressor

Answer 64

In the oil reservoir just below the unloaded valve

Question 65

Wher is the unloader valve located

Answer 65

Between the inlet air filter and the rotor