Here is the Cliff Notes overview of the four types of compressed air dryers, as defined by the Compressed Air and Gas Association.

1. Deliquescent dryers.  They're like waters softeners for compressed air, using soluble tablets to absorb moisture from compressed air.

   

2. Refrigerant dryers.  These have many of the same components as the refrigerator in your kitchen and work by chilling compressed air to condense and separate liquid.

    

3. Desiccant dryers contain highly porous beads such as silica gel or activated alumina which act like sieves at the molecular level, trapping water molecules.  Desiccant dryers come in an extraordinary range of sizes, shapes and styles, from $7 single use cartridges to multi-million dollar self-regenerating dryers

   

4. Membrane dryers.  These consist of hollow fibers that allow the "good" components of compressed air (mostly nitrogen and oxygen) to pass through while rejecting the "bad" component of untreated compressed air (i.e. water).  Sorry, no picture.

And remember, a dryer removes water vapor from the compressed air line.  Separators and filters remove liquid water.  If it's not designed to remove water, it's not a dryer.  

Shop here for deliquescent dryers sized for 7 to 100 CFM.  

Not sure what type of dryer is right for your needs?  Well, that's what I'm here for.  Click here to send me an email.