The materials in the hopper of the large cashew drying machine are uniformly spread on the mesh belt by the feeder through the conveyor belt. The mesh made of 12-60 stainless steel is driven by the transmission device in the dryer. The drying section is comprised of several independent hot air circulation units, in which the exhaust gas is discharged through special dehumidifying fan with discharge volume of each unit is controlling by a regulating valve.
In the upper circulation unit, the air coming out of the circulating fan enters the lower chamber through the side air duct with the air flow heated up by the heat exchanger and distributed through the distributor, and then blown onto the mesh belt by the jet flow, then enters the upper chamber after passing through materials. Drying process is a process in which the hot air flows through the material layer to transfer heat. The upper chamber is connected with the inlet of the fan. Part of the gas circulates and the other with lower temperature and higher moisture content as the waste flows are discharged through the dehumidification tube, the regulating valve and the dehumidification fan.
In the lower circulation unit of large cashew drying machine, the wind coming out of the circulating fan enters the upper chamber first, and the lower chamber is connected with the fan inlet by the side air duct and return air pipe. Most of the air circulate, while the other are exhausted.
Drying process of large cashew drying machine, generally comprised of three sets of equipment in series, includes premier drying section, the middle drying section and the final drying section. In the initial dry section, due to its high moisture content and poor air permeability, method of drying thin material with faster working speed and higher drying temperature is adopted. For material of temperature less than 60 ℃ during early drying period, drying gas temperature is below 120 ℃, residence time is 3 to 6 times longer than that of premier drying, the thickness of material is 2 to 4 times thicker than that in premier dryin