It has been suggested that either a radio frequency or microwave dryer might fit the bill. The answer shown is misleading because it doesn't address the crucial issue of cost.
Some simple calculations can help determine whether dielectric heating is economically sensible.
The questioner wants to dry 500 to 1,500 lb of herbs per hour, so I'll use 1,000 lb. Dielectric heating will evaporate 2.5 to 3 lb water per hour, so in this case, you need 742.3 divided by 3, or about 250 kW of dielectric heating. This approach will dramatically shorten the time at much lower capital cost. Copyright 2001 by Business News Publishing Co.