Abstract: A material drying system includes a pulse combustor having a combustion chamber and an elongate tailpipe forming a resonant system with the combustion chamber. The tailpipe has an inlet for material to be dried and an outlet through which the material is discharged in a pulsating gas stream when the combustor is in operation. The tailpipe discharges into a vertical drying duct which leads to a cyclone separator. Part of the exhaust gas leaving the cyclone separator is recycled and used to cool the combustion chamber and tailpipe. Part of the dried material leaving the cyclone separator can be mixed with new incoming wet material to lower the overall moisture content of the material to be dried. The pulse combustor provides a substantial portion of the motive force required to operate the system.