How Centrifugal compressors work?

How Centrifugal compressors work?
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1 Answer

Answer :

Answer: High-speed impellers increase the kinetic energy of the gas, converting this energy into higher pressures in a divergent outlet passage called a diffuser. Large volume of gas at moderate pressure.
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Related questions

What are the types of compressors?

Description : What are the types of compressors?

Last Answer : Answer: Positive Displacement, Centrifugal and Axial, rotary screw, rotary vane, rotary lobe, dynamic, liquid ring compressors.

Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply large quantities of air at a lower pressure ratio C. Centrifugal compressors are used to supply small quantities of air at a lower pressure ratio D. Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

Description : Which one of the following statements is correct? A. Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio B. Centrifugal compressors are used to supply ... . Centrifugal compressors cannot be run at high speed because of impeller, diffuser and casing.

Last Answer : ANSWER : B

Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Description : Which one of the following types of impeller vanes are most commonly used in centrifugal type compressors? A. Forward curved B. Radial C. Backward curved D. Tangential

Last Answer : ANSWER : C

Centrifugal compressors compared to reciprocating compressors (A) Require less space (B) Have quieter operation (C) Have lower operating costs (D) All (A), (B) and (C)

Description : Centrifugal compressors compared to reciprocating compressors (A) Require less space (B) Have quieter operation (C) Have lower operating costs (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

What are the methods of capacity control in centrifugal air compressors?

Description : What are the methods of capacity control in centrifugal air compressors?  

Last Answer : Centrifugal compressors operate best at the design point. They are prone to surging at flow rates less than 50% of the rated capacity. The following types of controls are employed in ... variable speed drives to match compressor output to meet varying load requirements is by speed control 

What is a surge point and how do you prevent surging, in centrifugal compressors?

Description : What is a surge point and how do you prevent surging, in centrifugal compressors?

Last Answer : Surge point is the point on the performance curve where a further decrease inflow (typically in the region of 50-70 % of rated capacity) causes instability, resulting in a pulsating flow, ... to thrust reversals, or excessive vibration. Bypass valves advents are commonly used to prevent surging. 

From base load operation and from achieving best specific energy consumption point of view, which of the following compressors are suitable? a) Single stage reciprocating compressors b) Centrifugal compressors c) Two stage reciprocating compressor d) Multi stage reciprocating compressor

Description : From base load operation and from achieving best specific energy consumption point of view, which of the following compressors are suitable? a) Single stage reciprocating compressors b) Centrifugal compressors c) Two stage reciprocating compressor d) Multi stage reciprocating compressor

Last Answer : b) Centrifugal compressors

From the point of lower specific energy consumption, which of the following compressors are suitable for part load operation? a) Two stage reciprocating compressors b) Centrifugal compressors c) Two stage screw compressor d) Single stage screw compressor

Description : From the point of lower specific energy consumption, which of the following compressors are suitable for part load operation? a) Two stage reciprocating compressors b) Centrifugal compressors c) Two stage screw compressor d) Single stage screw compressor

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Which of the statement is “True” for centrifugal compressors? a) The compressor should not be operated at full load b) The compressor should be operated at shut off pressure c) The compressor should not be operated with inlet-guide vane control d) The compressor should not be operated close to the surge point

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What are the types of bonnets?

Description : What are the types of bonnets?

Last Answer : Answer: Bolted bonnet, bellow sealed bonnet, screwed on bonnet, union bonnets, A U-bolt and clamp type bonnet, breech-lock bonnet, pressure seal bonnet

What are types of gate valves?

Description : What are types of gate valves?

Last Answer : Answer: Solid plane wedge, solid flexible wedge, split wedge, double disc parallels seats, double disc wedge, single disc single seat gate or slide, single disc parallel seats, plug gate valve.

What is lantern ring?

Description : What is lantern ring?

Last Answer : Answer: It’s a collection point to drain off any hazardous seepage or as a point where lubricant can be injected; it is in the middle of packing rings.

How to close a gate valve?

Description : How to close a gate valve?

Last Answer : Answer: Turn the hand-wheel in clockwise direction.

What are port types for gate valves?

Description : What are port types for gate valves?

Last Answer : Answer: Full port and reduced port. Default is reduced bore. Full port has to be specified in bom.

What is double disc globe valve?

Description : What is double disc globe valve?

Last Answer : Answer: Has two discs bearing on separate seats spaced apart, on a single shaft, for low torque, used for control valves.

Where WYE body globe valve is used?

Description : Where WYE body globe valve is used?

Last Answer : Answer: In line ports with stem emerging at 45 degree, for erosive fluids due to smoother flow pattern.

Where plug type disc globe valve is used?

Description : Where plug type disc globe valve is used?

Last Answer : Answer: For severe regulating service with gritty liquids such as boiler feedwater and for blow off service.

What are types of globe valve?

Description : What are types of globe valve?

Last Answer : Answer: Angle globe valve, plug type disc globe valve, WYE-body globe valve, composite disc globe valve, double disc globe valve.

What are characteristics of globe valve stem?

Description : What are characteristics of globe valve stem?

Last Answer : Answer: Always rising design, with disk nut at the lower end and handwheel at upper end.

What are globe valve disk types?

Description : What are globe valve disk types?

Last Answer : Answer: Flat faced type for positive shutoff, loose plug type for plug renewal or needle type for finer control.

What are globe valve port types?

Description : What are globe valve port types?

Last Answer : Answer: Full port: More than 85% of bore size, Reducer port: One size less than the connected pipe.

How to install a globe valve?

Description : How to install a globe valve?

Last Answer : Answer: Globe valve should be installed such that the flow is from the underside of the disk, Usually flow direction is marked on the globe valve.

What is needle valve?

Description : What is needle valve?

Last Answer : Answer: Full pyramid disc, same design as globe valve, smaller sizes, sw or threaded, flow control, disc can be integral with stem, inside screw, borged or barstock body and bonnet, manufacturers standard.

What is pinch valve?

Description : What is pinch valve?

Last Answer : Answer: Similar to diaphragm valve, with sleeves of rubber or PTFE, which get squeezed to control or stop the flow, Cast iron body, for very low service pressures like isolation of hose connections, manufacture standard.

What is dimensional standard for plug valve?

Description : What is dimensional standard for plug valve?

Last Answer : Answer: API 599.

What are eccentric plug valve?

Description : What are eccentric plug valve?

Last Answer : Answer: Off center plug, corrosive and abrasive service, on off action, moves into and away from seat eliminating abrasive wear.

What are permasil plug valve?

Description : What are permasil plug valve?

Last Answer : Answer: Plug valves with Teflon seat instead of sleeves, for on-off applications, can handle clean viscous and corrosive liquids, Graphite seat for high temperature applications. Drip tight shut off not possible.

What are Teflon sleeved plug valve?

Description : What are Teflon sleeved plug valve?

Last Answer : Answer: PTFE sleeve between plug and body of valve, low turning effort, minimum friction, temperature limitation, anti static design possible.

What is pressure balanced plug valve?

Description : What is pressure balanced plug valve?

Last Answer : Answer: With holes in port top and bottom connecting two chambers on top and bottom of plug, to reduce turning effort.

What are inverted plug design valve?

Description : What are inverted plug design valve?

Last Answer : Answer: Plug valve with taper portion up of plug. For 8” and higher size.

What are ventury pattern plug valve?

Description : What are ventury pattern plug valve?

Last Answer : Answer: Change of section through the body throat so graded to have ventury effect, minimum pressure loss.

What are short pattern plug valve?

Description : What are short pattern plug valve?

Last Answer : Answer: Valves with face to face dimension of gate valve, as a alternative to gate valve.

What is regular pattern plug valve?

Description : What is regular pattern plug valve?

Last Answer : Answer: Rectangular port, area almost equal to pipe bore, smooth transition from round body to rectangular port, for minimum pressure loss.

What are three patterns of plug valve design?

Description : What are three patterns of plug valve design?

Last Answer : Answer: Regular pattern, short pattern and ventury pattern.

What is metal seated lubricated plug valve?

Description : What is metal seated lubricated plug valve?

Last Answer : Answer: A plug valve with no plastic material, where grease is applied to contacting surfaces for easy operation.

What are uses of four way valve?

Description : What are uses of four way valve?

Last Answer : Answer: Reversal of pump suction and delivery, By pass of strainer or meter, reversal of flow through filter, heat exchanger or dryer.

What are the uses of three-way valve?

Description : What are the uses of three-way valve?

Last Answer : Answer: Alternate connection of the two supply lines to a common delivery vise versa, isolating one safety valve, division of flow with isolation facility.

What are types of flush bottom valves?

Description : What are types of flush bottom valves?

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What are flush bottom valves?

Description : What are flush bottom valves?

Last Answer : Answer: Special type of valves used to drain out the piping, reactors and vessels, attached on pad type nozzles.

What is float valve?

Description : What is float valve?

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What is foot valve?

Description : What is foot valve?

Last Answer : Answer: Valve used to maintain a head of water on the suction side of sump pump, basically a lift check valve with integrated strainer.

What is safety valve?

Description : What is safety valve?

Last Answer : Answer: Rapid opening (popping action) full flow valve for air and other gases.

What is relief valve?

Description : What is relief valve?

Last Answer : Answer: Valve to relieve excess pressure in liquids in situations where full flow discharge is not required, when release of small volume of liquid would rapidly lower pressure.

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Description : What are blow off valve?

Last Answer : Answer: It is a variety of globe valve confirming with boiler code requirements and specially designed for boiler blowoff service. WYE pattern and angle type, used to remove air and other gases from boilers etc.

What is sampling valve?

Description : What is sampling valve?

Last Answer : Answer: Usually of needle or globe pattern, placed in branch line for the purpose of drawing all samples of process material through the branch.

What is diverting valve?

Description : What is diverting valve?

Last Answer : Answer: This valve switch flow from one main line to two different outlets. WYE type and pneumatic control type with no moving part.

What is Quick acting valve?

Description : What is Quick acting valve?

Last Answer : Answer: Any on/off valve rapidly operable, either by manual lever, spring or by piston, solenoid or lever with heatfusible link releasing a weight which in falling operates the valve. Quick ... for water or for liquid service in general without a cushioning device to protect piping from shock.

What is Vacuum breaker?

Description : What is Vacuum breaker?

Last Answer : Answer: A special self-acting valve or any valve suitable for vacuum service, operated manually or automatically, installed to admit gas (usually atmospheric air) into a vacuum or low-pressure ... installed on high points of piping or vessels to permit draining and sometimes to prevent siphoning.

What is Throttling valve?

Description : What is Throttling valve?

Last Answer : Answer: Any valve used to closely regulate flow in the just-open position.

What is Spiral sock valve?

Description : What is Spiral sock valve?

Last Answer : Answer: A valve used to control flow of powders by means of a twistable fabric tube or sock.