1. Working Principle
The material in a hopper is uniformly spread on a mesh tape by a feeder, and the mesh tape is a 12 to 60-mesh stainless steel wire mesh and is dragged to move in the dryer by a transmission device. The drying section consists of a plurality of units, the hot air of each unit is independently circulated, and a part of tail gas is discharged by a special dehumidifying fan 6. The discharged waste gas quantity of each unit is controlled by an adjusting valve 7. In the upper circulating unit, the wind discharged by a circulating fan 5 enters the lower cavity of the unit from a lateral air flue, the airflow is heated through a heat exchanger 4 and distributed through a distributor 3 to form jet flow, and the jet flow is blown to the mesh tape, passes through the material and then enters the upper cavity. In the drying process, the hot airflow passes through the material layer to finish mass transfer and heat transfer. The upper cavity is connected with a fan inlet by an air pipe, most gas is circulated, and a part of gas has low temperature and is moist.
A large amount of gas is used as waste gas and discharged by a dehumidifying pipe, the adjusting valve and the dehumidifying fan. In the lower circulating unit, the wind from the circulating fan enters the upper cavity, is downwards heated by the heat exchanger, passes through the material layer and enters the lower cavity; and the lower cavity is connected with the fan inlet by the lateral air flue and an air return pipe, most gas is circulated, and a part of gas is discharged. The upper and lower circulating units can be flexibly allocated according to the requirements of users, and the number of the units can be selected according to the requirements of the users.
2. Main Application
The GDL belt dryer is continuous drying equipment. The GDL belt dryer is applied to drying of flaky, strip and granular materials with good air permeability, and particularly suitable for the materials with high water content and low temperature such as dehydrated vegetables and Chinese medicinal tablets. The dryer has the advantages of high drying speed, high evaporation strength and good product quality.