dynamic compressors

Question 1

how to increase effieciency and capcity in single stage compressor

Answer 1

diffuser vanes fit to inside of the housing

Question 2

increasing the speed in the single stage compressor will also increase the ______

Answer 2

volume

Question 3

adding additional impellers also known as multistaging will have this effect

Answer 3

increase volume and overall pressure ratio

Question 4

multistaging with intercooling between stages with 4-5 impellers can be achieved using this _____

Answer 4

bull gear

Question 5

impeller is used to accelerate or decelerate

Answer 5

accelerate

Question 6

volute and diffuser is used to accelerate or decelerate

Answer 6

decelerate

Question 7

3 types of centrifugal casings

Answer 7

sectional
horizontally split
vertically split

Question 8

casing usually on small units for low pressure ratio and small volumes

Answer 8

sectional

Question 9

casing most easily removed and limited to less than 1000 psi

Answer 9

horizontally split

Question 10

casing used for high pressure up to 10 000 psi

Answer 10

vertically split

Question 11

3 types of impellers

Answer 11

open
semi closed
closed

Question 12

impeller used in single stage and used in rough service environment

Answer 12

open

Question 13

impeller used in single and multi stage or final stage stage in axial compressor. blades may be straight radial, backwards leaning

Answer 13

semi closed

Question 14

impeller used in single and multi stage or final stage stage in axial compressor. enclosure of vanes allow you to achieve higher pressure ratio

Answer 14

closed

Question 15

directs gas flow into the compressor or from one stage to the next

Answer 15

guide elements

Question 16

controls compressor output and increase effieciency

Answer 16

inlet guide vanes

Question 17

stationary guides in a compressor

Answer 17

diaphragm

Question 18

result of the differential pressure between the impeller front and the back shroud

Answer 18

axial thrust

Question 19

thrust load is on this end of the compressor

Answer 19

suction end

Question 20

3 ways to minimize axial thrust

Answer 20

balance piston, thrust bearing, impeller arranged

Question 21

where is the balance piston located

Answer 21

discharge end immediately behind last impeller

Question 22

what end is the thrust collar installed

Answer 22

suction end

Question 23

impeller arrangement for high pressure

Answer 23

back to back

Question 24

impeller arrangement for maximum flow

Answer 24

double flow arrangement

Question 25

seal used to prevent poisonous gas to escape to atmosphere

Answer 25

labrinth seal

Question 26

seal used for high pressure

Answer 26

interlocking labrinth seal

Question 27

seal used at low pressure

Answer 27

carbon ring seal

Question 28

seal used where shaft speed is low

Answer 28

mechanical seal

Question 29

term to describe rotor being supported by bearing at both ends

Answer 29

beam

Question 30

3 parts of the axial compressor

Answer 30

rotor disc, stator and casing

Question 31

simplest way of controlling axial compressor

Answer 31

varying the speed by using gas or steam turbine as a prime mover

Question 32

2 types of axial rotors

Answer 32

drum and disc type

Question 33

problem in dynamic compressor that occur from dirty gases

Answer 33

blade fouling

Question 34

device used to inspect compressors

Answer 34

borescope

Question 35

term for flow reversal, which causes pressure drop at discharge

Answer 35

surge

Question 36

the term for when maximum flow has been reached

Answer 36

stonewall