What are the differences between wet and dry separators? Well, one is dry, and the other is wet. Dry separators use air, which is blown from its bottom compartment, where the blower is, and up through the angled deck above. The heavier materials move to the front and the lighter materials go to the back.

People often ask why they cannot just use one type for all applications. Both wet and dry separators have their pros and cons. Dry separators work well with granular materials—if something flows like sand, the air blows through the material, the heavy particles sink to the bottom and move forward, while the lighter particles fall back.

However, a downside of dry separators is the need for makeup air. For instance, if you are using a system that pushes air at 4,400 cubic feet per minute, you need to pull the same amount through the top of the air separator; otherwise, air will escape from the sides, creating a mess. To manage this, a bag house is needed which can match the air tables cubic feet per minute airflow.

Wet separators, on the other hand, use a liquid, usually water, while others use surfactants or sink-float tanks with calcium chloride or other salts. The main advantage of wet separators is that they do not require a bag house, which makes them cheaper and simpler. You could just have a granulator and a wet separator, and you are good to go. Wet separators work best for slightly larger, non-uniform pieces like long, stringy copper or bigger plastic pieces.

One downside of wet separators is that everything that passes through becomes wet. The system works by spraying water from the top, which flows downward, helping heavier particles climb up while the lighter particles fall to the lower deck and the water into a tank below, where the water is recirculated. However, moisture is lost in the process, making the waste and finished products heavier. Additionally, storing wet metals can lead to oxidation, affecting materials like aluminum and copper. Some people add citric acid to prevent copper from corroding or tarnishing.

If you are working with granular or fine materials, a dry separator is probably your best bet. For larger, chunkier pieces or if you want to avoid dealing with dust collection, a wet separator might be the better choice.

If you have any questions about wet or dry separators, please reach out to us directly.