An air receiver, also known as a storage tank or vessel, is a pressure-equipped container used to store compressed air before it enters a pneumatic system or piping network. It acts as a buffer between the compressor and the pressure fluctuations caused by changing demand. Essentially, it ensures a stable supply of compressed air even when demand varies.
- Storage: The primary function of an air storage tank is to store compressed air. This storage capability allows the system to meet short-term peak air demands that the compressor alone cannot handle.
- Pressure Stabilisation: A compressed air vessel helps stabilise the pressure in the system. It acts as a buffer, reducing the impact of pressure fluctuations caused by varying demand.
- Moisture Removal: Moisture can collect inside a compressed air container, especially in systems without an air dryer. The tank helps in removing this moisture, preventing corrosion and damage to pneumatic equipment.
- Energy Efficiency: By allowing the compressor to operate on a longer cycle and lower pressure bands, an air tank contributes to reducing energy consumption and extending the compressor's life.
Types of Compressed Air Vessels
Air storage containers come in various types and configurations, each suited for different applications and requirements. The most common types include:
- Vertical Storage Tanks: These are the most common type and are often used in applications where space is limited. They are designed to stand upright and are available in various sizes.
- Horizontal Storage Tanks: These are designed to lie horizontally and are typically used in applications where height is a constraint. They are also available in various sizes.
- Tank-Mounted Compressors: Some air compressors come as a package and are mounted on top of the storage tank. These are known as tank-mounted compressors and are commonly used in smaller applications.
Importance of an Air Vessel in a Compressed Air System
A compressed air vessel is an essential component of a compressed air system for several reasons:
- Minimising Pressure Fluctuations: An air storage tank helps in minimising unstable peaks in compressed air pressure, ensuring a stable supply of compressed air even when demand changes throughout the day.
- Reducing Compressor Load: By providing a reserve of compressed air, an air tank reduces the loading and unloading cycles on the compressor, making it work more efficiently and extending its lifespan.
- Improving Efficiency: A compressed air vessel can help improve the efficiency of an air dryer if placed before the dryer. It removes excess moisture from compressed air before it enters the air dryer, enhancing its performance.
- Safety: In an emergency, a compressed air storage container can help improve process safety by providing a supply of air that allows production processes and systems to be safely shut down.
Sizing a Compressed Air Storage Tank
Properly sizing a compressed air storage container is crucial for the effective operation of a compressed air system. Here are some guidelines to consider:
- Rule of Thumb: A good rule of thumb is to have a tank volume of about 3 to 4 gallons for each CFM (cubic feet per minute) or 10 to 15 liters for each liter/second of compressed air, depending on the type of air compressor and application.
- Pressure Needs: The size of the compressed air vessel should be determined by the application's pressure needs. The maximum pressure of the tank should be sized according to the output pressure of the compressor.
- Peak Demand: The air storage tank should be able to accommodate short-term peak air demands that the compressor alone cannot handle.
- Safety Considerations: Each compressed air vessel should be equipped with a pressure relief valve and other necessary safety and monitoring instruments like pressure gauges and water drains.
Maintenance and Safety
Regular maintenance and safety checks are essential to ensure the optimal performance and longevity of a compressed air tank. Here are some key points to consider:
- Draining Moisture: Moisture can collect inside a compressed air container, especially in systems without an air dryer. It is important to drain the tank at least once daily to prevent corrosion and damage to pneumatic equipment.
- Inspection: Regular inspection of the compressed air vessel for signs of corrosion or damage is crucial. This is especially important if the tank is situated outside.
- Safety Valves: Ensure that the compressed air tank is equipped with correctly rated safety valves and other air accessories for safe operation.
- Professional Advice: Always consult compressed air experts to ensure that the air vessel is suited to the compressed air system and requirements.
Common Questions
How does an air receiver buffer compressed air?
An air storage tank acts as a buffer between the compressor and the pressure fluctuations caused by changing demand. It stores compressed air and provides a reserve that can be used without running the air compressor, ensuring a stable supply of compressed air even when demand varies.
How does an air storage vessel extend the life of a compressor?
By providing a reserve of compressed air, a storage tank reduces the loading and unloading cycles on the compressor, making it work more efficiently and extending its lifespan. It also allows the compressor to operate on a longer cycle and lower pressure bands, reducing energy consumption.
How does a compressed air tank improve process safety in an emergency?
In an emergency, a storage tank can help improve process safety by providing a supply of air that allows production processes and systems to be safely shut down. This ensures that critical operations can continue for a short period, allowing for a controlled shutdown.