Test Your knowledge on Compressors – Online Quiz

Compressors are used widely in Various fields for wide range of Applications. Modern compressors are designed to compress the gas streams up to 900 bar. Most of the Chemical Process Industries use compressors to achieve the desired Reaction pressure, Refrigeration effect and to transport gases. Chemical Engineering Site already published articles on Reciprocating Compressor Trips and Safety Aspects and Centrifugal Compressor Surge – Choke which was well received by the users. This Compressor quiz also unveils you about the Selection, Types, Design and Performance Calculations, Components and Safety aspects of compressors.

Compressor Quiz

Its time to answer the questions in Compressor Quiz now

During normal operation, if the Molecular Weight of gas is decreased in centrifugal compresssor than the design value the power requirement will

Increase

Decrease

Doesnot change

Insufficient Data

None

To avoid Liquid entry in compressors …………….will help

Gas - Liquid separators

Insulating Inlet Lines

Steam Heating in Suction

Any of the Above

None

Volumetric efficiency of the reciprocating compressor decreases as the

Clearance Increases

Compression ratio increases

None of the above

Both A and B

None

Multi stage reciprocating compressors are used

To limit gas discharge temperature

To Limit Pressure Differential

To Save Power

All of the above

None

For minimizing the load on the thrust bearing ………………………is installed in the centrifugal compressor

Balance Piston

Labyrinth Seal

Diaphragm

Seal Oil System

None

API 617 standard is for

Axial and Centrifugal Compressors and Expander compressors

Reciprocating Compressors for Petroleum, Chemical and Gas Industry Services

Gas Turbines for the Petroleum, Chemical and Gas Industry Services

Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries

None

In Double acting Reciprocating compressor compression takes place

Only in head end of the cylinder

Only in crank end of the cylinder

In both head end and crank ends of the cylinder

None

During Centrifugal Compressor Surge, the following occurs

Rapid flow reversals

Compressor vibrates

Gas Temperature rises

All of the above

None

An example for Anti Surge control system in a centrifugal compressor is

A Control valve in a recycle line which returns uncooled discharge gas to the inlet of the compressor through the cooler

A Control valve in a discharge line to Vent the gas to atmosphere

Both (A) and (B)

None of the above

None

10.

For Dual duty with different Molecular weights of gases which compressor type is preferred?

Centrifugal compressors

Reciprocating Compressors

Screw compressors

None of the above

None

11.

'Stonewalling' or 'Choke' in centrifugal compressor is attained when

The flow through the compressor is minimum

The gas velocity in the machine attains sonic velocity

Maximum Polytropic Head is achieved

All of the above

None

12.

Discoloration of Valve plate occurs due to

Liquid Slugging

High Temperature

Voltage Unbalance in Motor

All of the above

None

13.

What is the discharge Pressure of the 4 stage compressor if the pressure in first stage discharge is 1 bar Abs and third stage discharge is 16 bar Abs?

64 bar Abs

16 bar Abs

32 bar Abs

256 bar Abs

None

14.

Reciprocating compressor has to be started in

Closed Discharge

Open Discharge

None

15.

Best way to reduce Noise in compressor house is

Closed Building

Acoustic Insulation

None

16.

Refrigeration compressors are used to maintain the

Refrigerant Condenser Pressure

Process Vapor Side - Evaporator Pressure

Refrigerant Side- Evaporator Pressure

None of the above

None

17.

What is the discharge temperature of a single stage reciprocating air compressor which compresses atmoshpheric air at 30 Deg C to 2.5 bar A?

83 Deg C

440 Deg C

75 Deg C

122 Deg C

None

18.

As per API 618, maximum allowable discharge temperature of Reciprocating compressor is

150 Deg C

250 Deg C

200 Deg C

300 Deg C

None

19.

Which type of Cylinder cooling is preferred if the predicted discharge temperature of the Reciprocating compressor is 125 Deg C

Static Filled Coolant System

Atmospheric Thermosyphon System

Pressurized Thermosyphon System

Forced Liquid Coolant system

None

20.

To reduce pressure fluctuation and Vibration ……………….. Is used in Reciprocating compressors

Relief Valves

Intercoolers

Pulsation Dampener

Separator

None

21.

For Very High Pressure Hydrogen Service which compressor is preferred?

Multi Stage Reciprocating Compressor

Horizontally Split Multi Stage Centrifugal Compressor

Vertically Split Multi Stage Centrifugal Compressor

Screw compressor

None

22.

Which one of the following statement is not true

Diaphragm is a stationary component in Centrifugal compressor

Labyrinth seal MOC is harder than the Shaft MOC

Surge flow is less than the Stonewall flow

Active Magnetic Bearing is used for Oil free application

None

23.

In forced Coolant System in the Reciprocating Compressor Jacket Cooling, the coolant temperature is

Less than the Suction Gas Temperature

6 Deg C warmer than the Suction Gas Temperature

Equal to the Suction Gas Temperature

Equal to the Dischrge Gas Temperature

None

24.

Side stream type centrifugal compressors are used in

Refrigeration Service

Process Air Service

Hydrogen Service

None of the above

None

25.

In a Centrifugal Compressor Operating at At constant speed, The pressure differential between discharge and suction will increase when

Increased inlet pressure

Decreased inlet temperature

Increased molecular weight

All of the above

None

26.

Low Suction Pressure Trip in reciprocating compressor is provided in

Hydrogen Service Suction Pressure > 12 bar

Air Service

Hazardous gas service operating slightly above atmospheric condition in suction

Refrigeration service Suction pressure > 5 bar

None

27.

Steam Turbines are not used as a driver in Reciprocating compressor because of

Surge Phenomenon

Excitation of Torsional critical speed does not allow variable speed operations.

Steam Turbines reliability is poor compared to Electric Motors

None of the above

None

28.

Rotary Screw Compressor is

Positive Displacement Type Compressor

Dynamic Type Compressor

None

29.

Which one of the following doesnot require shutdown of the Reciprocating compressor?

High Gas disharge Temperature

High Oil Filter Differential Pressure

High Vibration

High Level in Suction Separator

None

30.

Hydraulic accumulator used in Lube oil circulation system is

As Additional Storage Reservoir

An Energy Storage Device

None

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