A sawn wood drying system, which allows to take advantage of the heat contained in the dry wood that leaves the system to preheat the wet and cold wood that enters the system, the system comprising: a heating chamber, a drying chamber and a cooling chamber, sequentially arranged, and a transport path that allows the transfer of sawn wood through these three chambers; a first air circulation system, which provides a first high temperature air flow inside the drying chamber; and a second air circulation system that provides a second air flow, independent of the first air flow, which allows the heating chamber to be in fluid communication with the cooling chamber by means of external chambers or ducts connecting both chambers.

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.

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.

A grain dryer unload system is presented that facilitates operation of a discharge system independent of a metering system. A motor connects to an axle that connects to the discharge system, which may be a drag chain, a belt or an auger. The axle also connects to a metering system. A clutch mechanism is connected to an end of the axle and is positioned between the discharge system and the metering system. When the clutch mechanism is in an engaged position, the motor simultaneously operates the metering system and the discharge system. However, when the clutch mechanism is in a disengaged position, the motor operates the discharge system while the metering system does not operate. This arrangement facilitates easier cleaning of the grain dryer without introducing the fines into the grain or a connected grain storage device.

An ecosystem operated in a plant having a drying unit is provided. The ecosystem includes: a regenerative thermal oxidization unit for processing a waste gas to produce a hot gas; a first hot gas pipeline connected to the regenerative thermal oxidization unit and the drying unit, wherein the hot gas is transferred from the regenerative thermal oxidization unit to the drying unit via the first hot gas pipeline; a heat recovery unit disposed at the first hot gas pipeline to absorb heat from the first hot gas pipeline; an absorption refrigeration unit connected to a target to be cooled; and a hot liquid pipeline connected to the heat recovery unit and the absorption refrigeration unit, wherein the heat recovery unit transfers heat from the first hot gas pipeline to the absorption refrigeration unit via the hot liquid pipeline to actuate the absorption refrigeration unit to cool the target.

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.

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. A cooling air bypass system having a plurality of bypass tubes brings bypass air into the lower plenum from outside the grain dryer without having the bypass air come into contact with the grain being cooled in the cooling section. The cooling air bypass system includes a grill with an adjustable damper to adjust the amount of bypass air that flows into the lower plenum.

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.