Steam heating disc dryer Power plate dryer machine

PLG Series Continuous Plate Dryer is also called disc dryer, it is a high-efficiency conducting and continuous Drying Equipment. Its unique structure and operating principle determine that it has advantages of high heat efficiency, low energy consumption, small occupied area, simple configuration, easy operation, and control as well as good operating environment and etc. It can be widely used in the drying processes in the fields of chemical, pharmaceuticals, agricultural, foodstuff, feed, and other industries for drying powder and granules materials.

2. Working principle of disc dryer:

The plate dryer uses steam, hot water or heat transfer oil as the heating medium, and the shaft end is equipped with a rotary joint for the import and export of the heat medium. The heating medium is divided into two channels, which respectively enter into the jacket of the drying shell and the inner cavity of the propeller shaft. The body and the propeller shaft are heated at the same time, and the materials are heated and dried by means of conduction heating. The dried materials are fed into the feeding port of the dryer quantitatively and continuously by the screw feeder. After entering the feeder, the materials are overturned and stirred by the rotation of the paddles, and the heating interface is constantly updated. The materials are in contact with the body and paddles, and are subject to heat and mass transfer, so that the surface water contained in the materials is evaporated. At the same time, the materials are transported to the discharge port in a spiral path with the rotation of the propeller blade shaft. During the transportation, the mixing continues, and the separated water continues to evaporate. Finally, the dried product is discharged from the discharge port.

3.1. Drying Tray
- Designing pressure: generally 0.4Mpa, and the max. pressure is 1.6 MPa.
- Max. working pressure: generally ≤0.4Mpa, and the max. pressure is 1.6 MPa.
- Heat source: steam, hot water, or thermal oil: Use hot water as heat source when the drying plates' temperature is 100°C; Use saturated water steam ≤0.4Mpa or steam-gas when the drying plates' temperature is 100°C~150°C; Use thermal oil when the drying plates' temperature is 150°C~320°C;

3.2. Material Transmission System
- Revolution of main shaft: 1~10 rpm, electromagnetism or transducer timing.
- Rake arm: 2 to 8 rake arms will be fixed on the main shaft on the every layer.
- Rake blade: the rake blades are hinged to the rake arms and float with the surface of the plate. There're several types of rake blades.
- Roller: For the material that is easy to agglomerate, or required to be grinded, the rollers shall be placed at the appropriate place to reinforce the heat transfer and drying process.

3.3. Three types of dryer body: normal pressure, sealed, and vacuum
- Normal pressure: The dryer body is cylindrical or octagonal and the structure can be integrated or separated. The ducting system for the heat source can be placed inside or outside of the dryer.
- Sealed: The dryer body is cylindrical and it can bear the interior pressure of 5KPa. The ducting system for the heat source can be placed inside or outside of the dryer.
- Vacuum: The dryer body is cylindrical and the design pressure is 0.1MPa. The ducting system for the heat source is placed inside of the dryer.

3.4. Air Heater
The air heater is usually used to meet larger evaporation capacity requirements in order to increase drying efficiency.