Abstract: A pulse combustion dehydration apparatus includes a pulse combustor designed to operate with a low pressure fuel gas supply and having valve means to stop the supply of gas to the combustion chamber during high pressure portions of the pulse combustion cycle. Gas enters the combustion chamber through a fuel distributor having a series of radial gas outlets downstream of an annular flame trap through which combustion air is admitted to the combustion chamber from an air cushion chamber. These features increase the amplitude of the combustion cycle and reduce the amount of residual flame in the combustion chamber, resulting in a strong cycle. An air bypass pipe from the air cushion chamber to the exhaust pipe apparently increases the compression in the combustion chamber from the returning pressure waves. The deydration apparatus further includes a rotary drum into which material is to be dehydrated is delivered in the exhaust gas stream from the exhaust pipe of the pulse combustor.

Abstract: A dehydrator for fluent materials includes a pulse combustor and a cyclone separator having a cylindrical cyclone chamber and a central gas discharge tube. The pulse combustor has a finned tail pipe which is contained within a casing disposed generally tangentially to a cylindrical wall of the cyclone chamber. Material to be dried is introduced into the tail pipe and is discharged in a spiral pattern that flows downwardly around the gas discharge tube. Material in the gas stream falls into a collection hopper below the cyclone chamber. Gases leave through the gas discharge tube. In an alternative embodiment, a simpler dried material collection chamber is used.

Abstract: Various improvements in pulsating combustors for use in dehydration are disclosed. In one aspect of the invention, gas is introduced into the combustion chamber through a fuel distributor providing a bluff body within the combustion chamber so that a striated charge having streaks of gas and air is produced. The tail pipe of the combustor has an enlarged outer portion provided with an inlet for material to be dehydrated so that an injector action occurs at the point of material entry. A valve may be associated with the material inlet so that the material is introduced in timed relation to the pulse combustion cycle. Other aspects of the invention concern a rotary mechanically driven air admitting valve for the combustion chamber and a gas supply arrangement designed to provide for low- and high-fire operating modes.

Abstract: A pulse combustion apparatus capable of operating using a variety of different fuels includes an exchangeable fuel supply nozzle disposed adjacent a primary air inlet valve and separated from secondary air inlet valves by baffle means. The baffle means co-operates with the nozzle to define a metering orifice through which the primary air flows. The size of the orifice is determined by the axial position of the nozzle so that nozzles for different fuels can be positioned in axially different positions to meter the primary air as required to maintain continuous combustion commensurate with a pulse cycle of reasonable strength.