A grain dryer having a mixed-flow heating section, a tempering transition section, and a vacuum-cooled crossflow cooling section. A fan positioned on the end of the dryer creates a negative pressure in the cooling plenum that pulls air through the grain, warming the air while cooling the grain. This warmed air is pulled through the fan and then passed through a heater to bring it to appropriate drying temperature. This air is then pushed into a heating plenum, where it passes through a mixed-flow grain column, drying the grain, and then exhausted to ambient air.

An improved grain dryer is presented having a mixed-flow heating section having a plurality of inlet ducts connected to the plenum that facilitate air flow into the grain column from the heated and pressurized heat plenum, and a plurality of exhaust ducts connected to openings in the exterior wall that facilitate air flow out of the grain column. A tempering section is positioned below the heating section and includes solid walls that reduce air flow through the grain column. A cooling section is positioned below the tempering section and includes perforated walls that facilitate air flow through the grain column and into the plenum. In use, heated air is forced outward through the mixed-flow heating section heating and drying the grain and air is pulled through the cross-flow cooling section cooling the grain. Air pulled through the cross-flow cooling section is recycled into the mixed-flow heating section thereby recycling heat.

Method and apparatus for drying granular resin material by drawing vacuum over heating resin material in a vessel, while periodically purging the vessel with the material therein with dry air and bathing the vacuum dried material with dry air until furnished to a processing machine.

An embodiment of the present invention provides a vacuum drying apparatus and a vacuum drying method. The vacuum drying apparatus includes a chamber in which a substrate table is arranged, the chamber being provided with a wind deflector therein, wherein the wind deflector comprises a top opening, a bottom opening and a body part connecting the top opening with the bottom opening. During the vacuum drying, the bottom opening is in tight contact with a surface of the substrate table, and there is a gap between the top opening and the top of the chamber and a material on the substrate table is covered by the wind deflector.

A combustible pellet drying system includes a valveless pulse combustor and a drying column. The drying column includes a first drying region and optionally a second drying region. The first drying region receives heated drying gas from the pulse combustor to dry a quantity of moist pellets flowing downwardly through the drying column. Moisture-laden exhaust gas from the first drying region is processed by a condenser to remove water and recover thermal energy therefrom, and to produce a cooled dried exhaust gas which may be reheated by passing through a jacket around the pulse combustor. The reheated dry gas is introduced into the second drying region to further dry the pellets. The second drying region is preferably a downwardly expanding cone configuration. The drying column includes a plurality of temperature sensors. Adjacent temperature sensors may be used to determine a level of pellets within the drying column. The combustible pellets are preferably coal pellets.

A combustible pellet drying system includes a valveless pulse combustor and a drying column. The drying column includes a first drying region and optionally a second drying region. The first drying region receives heated drying gas from the pulse combustor to dry a quantity of moist pellets flowing downwardly through the drying column. Moisture-laden exhaust gas from the first drying region is processed by a condenser to remove water and recover thermal energy therefrom, and to produce a cooled dried exhaust gas which may be reheated by passing through a jacket around the pulse combustor. The reheated dry gas is introduced into the second drying region to further dry the pellets. The second drying region is preferably a downwardly expanding cone configuration. The drying column includes a plurality of temperature sensors. Adjacent temperature sensors may be used to determine a level of pellets within the drying column. The combustible pellets are preferably coal pellets.

A grain dryer has pair of heating columns in communication with an upper plenum, and a pair of cooling columns in communication with a lower plenum. A heater is located between the lower plenum and the upper plenum, wherein air is heated by the heater as air in the lower plenum is pulled through the heater and into the upper plenum. As the grain flows into the cooling column, it is exposed to cooling air being pulled through the cooling column into the lower plenum. Ductwork adjacent each heating column includes vertical sections arranged along a length of the grain dryer. Each vertical section has a fan located adjacent the uppermost horizontal level of the heating column. Each fan takes a suction from the ductwork to draw heated air from the upper plenum through the heating column.

An improved mixed flow grain dryer is presented having a grain column with upper, middle and lower drying sections. The system includes a set of plenums and ducts configured to move air through the middle and lower drying sections at one or more lower temperatures, recover the air moved through the middle and lower drying sections, and move the recovered air through the upper drying section at a higher temperature. The system is configured to move grain through the upper drying section, then through the middle drying section, then through the lower drying section, while also: moving air of one or more lower temperatures through lower drying section and middle drying section, combining air moved through lower drying section and middle drying section, and moving the combined air through the upper drying section at a higher temperature.

An improved mixed flow grain dryer is presented having a grain column with upper, middle and lower drying sections. The system includes a set of plenums and ducts configured to move air through the middle and lower drying sections at one or more lower temperatures, recover the air moved through the middle and lower drying sections, and move the recovered air through the upper drying section at a higher temperature. The system is configured to move grain through the upper drying section, then through the middle drying section, then through the lower drying section, while also: moving air of one or more lower temperatures through lower drying section and middle drying section, combining air moved through lower drying section and middle drying section, and moving the combined air through the upper drying section at a higher temperature.