Pregunta 1
Pregunta
In an ammonia absorption system, the strong liquor is composed of which of the following?
Respuesta
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Ammonia and salt
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Ammonia and brine
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Water and ammonia
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None of the above
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All of the above
Pregunta 2
Pregunta
At a pressure of around 240 kpa, ammonia will boil off at a temperature of about___, in the evaporator by absorbing heat from the medium to be cooled?
Respuesta
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-89 degrees
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-65 degrees
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-15 degrees
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10 degrees
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None of the above
Pregunta 3
Pregunta
An intercooler used in a compression refrigeration system serves to do which of the following?
Pregunta 4
Pregunta
Which of the following is incorporated between the discharge and suction of two separate single stage compressors in order to remove some of the heat added in the low pressure stage?
Respuesta
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Intercooler
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Aftercooler
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Evaporator
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Condenser
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None of the above
Pregunta 5
Pregunta
In order to handle large volumes of vapor coming from the evaporator, multi- stage plants may employ which of the following for the first of low pressure stage?
Pregunta 6
Pregunta
Which of the following maintains a constant level of liquid refrigerant in the evaporator?
Respuesta
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Expansion valve
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Liquid receiver
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Evaporator float valve
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None of the above
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All of the above
Pregunta 7
Pregunta
The different types of refrigeration plants are which of the following?
Pregunta 8
Pregunta
In the duplex compressor system, the condenser for the first stage is the evaporator for the second stage?
Pregunta 9
Pregunta
Which of the following are different types of construction for an evaporator?
Respuesta
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Bare tube
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Finned Tube
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Plate surface
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1 and 2
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All of the above
Pregunta 10
Pregunta
Which of the following are major components of the high pressure ammonia refrigeration system?
Respuesta
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Compressor
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Condenser
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Evaporator
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Liquid Receiver
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All of the above
Pregunta 11
Pregunta
Some of the most common refrigerants used today are which of the following?
Respuesta
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Refrigerant R- 12
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Refrigerant R- 22
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Refrigerant R- 134a
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Ammonia
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All of the above
Pregunta 12
Pregunta
Which of the following properties should fluids, used as a refrigerant, possess?
Pregunta 13
Pregunta
When starting up a compressor and a leak has been found, which of the following steps would be the corrective action?
Respuesta
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Shut down the compressor until the leak is repaired
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Continue with the start up and ignore the leak
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If possible, bypass the line which is leaking
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All of the above
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None of the above
Pregunta 14
Pregunta
What would be the final step in the start up of a compressor?
Respuesta
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Check the gearbox oil level
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Slowly load up the compressor
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Close the breaker for the compressor motor
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Check for leaks and unusual noises
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None of the above
Pregunta 15
Pregunta
Which of the following steps comes first when starting up a compressor that was taken down for maintenance?
Respuesta
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Start the compressor
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Check oil levels
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Ensure no one is working on the compressor
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Turn on the cooling water for the compressor cylinders
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Open the suction and discharge valves
Pregunta 16
Pregunta
Which of the following should never be placed in the line between compressor and receiver, unless a safety valve is used?
Respuesta
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Drain valve
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Pressure regulator
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Orifice plate
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Shut off valve
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None of the above
Pregunta 17
Pregunta
Air receivers serve to perform which of the following functions?
Respuesta
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Act as a reservoir in the compressed air system
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Acts to dampen pulsations in the discharge pressure
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Allows moisture, dust, and oil to settle out from the air
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All of the above
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None of the above
Pregunta 18
Pregunta
The standard desiccant used in an air dryer system is which of the following?
Respuesta
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Activated alumina
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Silica gel
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Potassium oxide
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1 and 2
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None of the above
Pregunta 19
Pregunta
Which of the following are components of an air dryer system?
Respuesta
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Prefilters
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Dryer tanks or towers
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Afterfilters
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All of the above
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None of the above
Pregunta 20
Pregunta
Which of the following functions does the dry air receiver serve to do?
Respuesta
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Stabilizes the system pressure as it acts as a demand reservoir
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Helps avoid overloading the air purification system with surges in air demand
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Dampens out the dew point and temperature spikes
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All of the above
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None of the above
Pregunta 21
Pregunta
Which of the following functions does the wet air receiver serve to do?
Respuesta
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Stabilize flow though the air driers on system load changes
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Additional moisture separation
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Provides storage capacity to prevent rapid compressor cycling
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All of the above
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none of the above
Pregunta 22
Pregunta
What is the main purpose of an intercooler?
Respuesta
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To remove any entrained moisture
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To reduce the volume of the air
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To maintain the outlet temperature
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All of the above
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None of the above
Pregunta 23
Pregunta
Which of the following are some of the reasons for using intercoolers and aftercoolers to cool down the air?
Respuesta
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To condense out water vapor and drain from the system
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To remove all oil vapors that will have detrimental effects on the system
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Decrease the amount of power to compress the air
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To make cylinder lubrication more effective
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All of the above
Pregunta 24
Pregunta
Some common methods used to reduce “surging” would be?
Respuesta
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Throttling the inlet valve
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Reducing the compressor speed
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Venting of the discharge line to atmosphere, or to the suction line
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All of the above