A receiver tank is a vital part of any compressed air system. Deciding where to install a receiver tank depends on what function it is meant to perform.
A receiver tank can serve one or several of the following:
Air compressors 10 horsepower and smaller are usually mounted directly to receiver tanks. The compressor outlet feeds directly into the tank. The receiver tank sizing rule of thumb for small systems is one gallon per rated SCFM @ 100 psig.
It’s normal to oversize a wet receiver tank on a small compressed air system because the tank serves all of the functions listed above, except for dry air storage. If using an external compressed air after-cooler and moisture separator, install these before the receiver tank.
In many applications compressed air must be clean and very dry. Pharmaceutical manufacturing, cryogenics, food preparation, and laboratory testing are a few industries where ultra-dry compressed air is required, often a pressure dew point of -40F or lower is specified. In these applications, even trace amounts of water vapor can cause expensive process failures. Here the air treatment system will consist of filters and a multi tower solid adsorbent regenerative dryer. These components are typically followed by a dry receiver tank. We can think of the wet air receiver prior to the dryer system as supply storage and the dry air receiver after the dryer and filters as demand storage.
Demand storage is needed to minimize system pressure loss when the process experiences spikes in demand. Without the dry receiver, the dryer and filters would experience increased flow and decreased pressure. The compounded demand increase would ultimately cause the dryer and filters performance to decrease or fail all together causing the process to fail.
The dry air receiver also serves to minimize any temperature and or dew point spikes caused by the operation of the regenerative dryer system.
A wet receiver tank is always a good choice just after the compressor prior to a dryer because it will perform the many functions noted above. As a compressor outlet buffer it will also minimize compressor cycling. The cost of the receiver tank is minimal compared to the wear and expense of over cycling a compressor.
The wet air receiver also serves as supply storage to a regenerative dryer when a process requires very dry clean air.
A dry air receiver is a good choice downstream of a process dryer or critical drying system. It will guarantee proper dryer performance and reduce the risk of expensive process upsets.