Screw Compressors Flashcards
What is a screw compressor?
A screw compressor is a type of positive displacement compressor that uses two interlocking helical screws to compress air or gas.
True or False: Screw compressors are typically used for low-pressure applications.
False
What is the main advantage of using a screw compressor over a piston compressor?
Screw compressors provide a more continuous flow of compressed air and higher efficiency at larger capacities.
Fill in the blank: The two main types of screw compressors are _____ and _____.
oil-injected, oil-free
What is the function of the rotors in a screw compressor?
The rotors compress the air or gas by trapping it between their helical threads as they rotate.
What is the typical pressure range for industrial screw compressors?
Typically between 80 to 150 psi.
True or False: Screw compressors require lubrication.
True
What component is used to regulate the pressure in a screw compressor?
A pressure switch or controller.
What is the purpose of the oil separator in an oil-injected screw compressor?
To separate the oil from the compressed air before it is delivered to the system.
What is the typical lifespan of a screw compressor?
15 to 20 years with proper maintenance.
Name one common application for screw compressors.
Manufacturing, pneumatic tools, or HVAC systems.
What does the term ‘specific power’ refer to in relation to screw compressors?
The power needed to compress a unit volume of air or gas.
Fill in the blank: The efficiency of a screw compressor can be affected by _____ and _____.
temperature, pressure
What is the role of the intake valve in a screw compressor?
To control the amount of air entering the compressor.
True or False: Screw compressors can be used in both stationary and portable applications.
True
What is the primary cooling method used in screw compressors?
Air or water cooling.
What does the term ‘intercooling’ mean in the context of screw compressors?
The process of cooling the compressed air between stages to increase efficiency.
What is the typical rotational speed range for screw compressor rotors?
1,000 to 10,000 RPM.
What is one major disadvantage of oil-free screw compressors?
They are generally less efficient and have a higher initial cost.
Name a key maintenance task for screw compressors.
Regular oil changes or filter replacements.
What is the purpose of the thermal protection system in a screw compressor?
To prevent overheating of the compressor.
True or False: Screw compressors are less noisy than piston compressors.
True
What is ‘screw compressor capacity control’?
Methods used to adjust the output of the compressor to meet varying demand.
Fill in the blank: The _____ of a screw compressor is designed to minimize wear and tear on the rotors.
lubrication system
What is the benefit of variable speed drives in screw compressors?
They allow for precise control of the compressor output, improving energy efficiency.
What does the term ‘compressor unloading’ refer to?
A method to reduce the compressor’s output when demand is low.
Name a common troubleshooting issue with screw compressors.
Excessive vibration or noise.
What is the typical discharge temperature range for a screw compressor?
Between 180°F to 250°F.
True or False: The design of screw compressor rotors is critical for optimal performance.
True
What is the impact of high ambient temperatures on screw compressor performance?
It can lead to reduced efficiency and increased wear.
What is the role of the compressor control panel?
To monitor and control the operation of the compressor.
What safety feature should be included in a screw compressor system?
Pressure relief valves.
Fill in the blank: Screw compressors can be classified based on their _____ and _____ type.
lubrication, cooling
What is the purpose of using a frequency inverter in screw compressors?
To adjust the motor speed for varying load conditions.
True or False: Screw compressors are typically less efficient at lower loads.
True
What is the importance of air filtration in screw compressors?
To prevent contaminants from entering the compressor and damaging components.
What does ‘system integration’ mean in the context of screw compressors?
Connecting the compressor with other system components for optimized performance.
What type of maintenance schedule is recommended for screw compressors?
Regular preventive maintenance every 3 to 6 months.
What is the expected efficiency range for screw compressors?
70% to 90%.
What is one advantage of using oil-injected screw compressors?
They provide better cooling and lubrication.
What can cause a screw compressor to overheat?
Insufficient lubrication, high ambient temperatures, or blocked airflow.
Fill in the blank: The _____ of a screw compressor should be checked regularly to ensure proper operation.
oil level
What common material is used for screw compressor rotors?
Hardened steel.
What does the term ‘volumetric efficiency’ refer to in screw compressors?
The ratio of the actual volume of air compressed to the theoretical volume.
True or False: Screw compressors can be used for both gas and air compression.
True
What is the role of the heat exchanger in a screw compressor system?
To cool the compressed air before it is delivered to the application.
What is one indicator of a failing screw compressor?
Increased energy consumption or abnormal noises.
Fill in the blank: The _____ of a screw compressor is critical for ensuring safety and efficiency.
maintenance schedule
