Pulse atomization spray drying is superior to conventional spray drying in many ways and for many reasons. This page describes some of the practical performance benefits and considerations of pulse drying.
Successful Materials
We have experience with over 200 different materials in our dryer, and have obtained very favorable results on minerals, specialty chemicals, foods and nutraceuticals.
The low degradation in the pulse drying process contributes to better taste and color of food products. This also produces similar benefits in other sensitive products.
There are four reasons for this:
- The liquid is evaporated very rapidly by using high temperatures for a very short time. The heat transfer in the atomizing zone of the dryer is very high, and evaporative cooling protects the feed material. We have demonstrated that we can dry egg whites and other delicate proteins at 1000 F, without damaging them at all.
- No shear is applied to the liquid. The PCS Dryer does not use high-pressure pumps, nozzles or rotary disks. The liquid, slurry, or paste is fed at low pressure (~1psi) and atomization occurs in the exhaust jet of the pulse atomization burner.
- The pulse dryer is capable of very low dryer exhaust temperatures, which, when combined with very rapid drying, produces freeze-dry quality powders.
- The high-velocity combustor exhaust that comes into direct contact with the liquid contains less oxygen than a conventional spray dryer’s heated air.
Concentration of Feeds Yields Lower Costs
For most materials currently spray dried, the PCS Dryer can handle the same feed in a higher concentration of solids. This yields higher powder production rates and lower processing costs per finished pound. It also means that a smaller, less-expensive pulse dryer can handle the same throughput as a larger, more-expensive conventional spray dryer. In one recent dryer sale, we were able to cut the number of dryers required in half.
Special Materials
Due to our unique atomization method and very large operating envelope, we have made successful powders with many difficult or ‘un-dryable’ materials.
Problem Materials
While we are adding to our list of successful tests on often a weekly basis, we’ve also discovered a few materials that do not perform well in our pulse atomization spray dryer.