Systems for drying granular materials, such as resin granulates, powdered materials, and agricultural grains, can include a storage vessel for holding the granular material; a drying hopper having a body defining an interior volume configured to receive the granular material; a diffuser configured to direct process air into the interior volume; a vacuum source for transferring the granular material from the storage vessel and to the drying hopper; and a moisture sensor for determining a moisture content of the granular material at a location upstream of the drying hopper. At least one of the residence time of the granular material within the drying hopper, and the temperature, humidity, and flow rate of the process air are regulated based on the moisture content of the granular material measured upstream of the drying hopper at, for example, the storage vessel.

An installation for crystallizing and drying granular polymer material with a low level of crystallinity includes: a crystallization hopper, in which the granular polymer material is maintained in an agitated state and is processed with a first gas flow which is heated to a first temperature; a heating hopper which is arranged downstream of the crystallization hopper and in which the crystallized granular polymer material is heated to a second temperature which is greater than the first temperature, a drying hopper which is arranged downstream of the heating hopper and in which a predefined level of pressure reduction is maintained to dry the granular polymer material, and a supply hopper which is arranged downstream of the drying hopper and which is provided to supply a transformation machine with the granular polymer material.

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. Outer most ducts of the inlet and exhaust ducts, which are positioned closest to end walls of the grain column, are configured to reduce bridging or grain between the outer most ducts and the end walls of the grain column.

A plastic dehumidification and drying device includes a dehumidification host system, an air supply system and at least one plastic processing system. The air in the dehumidification host system is cooled by the host windmill through a secondary condenser and enters a host honeycomb runner. The host honeycomb runner uses a host regeneration windmill and a host regeneration heater to send regeneration air to help absorb moisture. The host honeycomb runner sends the dehumidified air to the plastic processing system for drying plastics. The air returns to the dehumidification host system and passes through the host filter, then the closed cycle is carried out through the primary condenser and the host windmill. The primary condenser and the secondary condenser are provided with ice water to cool the moisture in the contracted air. The air supply system supplies air to the dehumidification host system to supplement the pressure loss, further reduce the dew point and increase the efficiency of dehumidification.

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. Outer most ducts of the inlet and exhaust ducts, which are positioned closest to end walls of the grain column, are configured to reduce bridging or grain between the outer most ducts and the end walls of the grain column.

A hopper for the heat treatment of a material contained therein includes a casing with an upper portion, into which the material to be treated is introduced, and a bottom part or lower portion, from which the material is discharged; a diffuser of a process fluid located inside the hopper; a system for introducing the process fluid inside the diffuser; a mixing chamber arranged to enclose at least the lower portion of the hopper externally; a system for introducing the process fluid inside the mixing chamber; and a system that fluidically connects the interior of the mixing chamber with the interior of the diffuser.