The rake vacuum dryer is more applied to low temperature drying in the process of operation. The heating medium is mainly hot water when it is used, and its hot water is poured into the conventional vacuum rake dryer clip. If the velocity is too small, it is easy to form a "short circuit" phenomenon, so that the jacket heating is not uniform, if the flow rate is too high. Large, although can reduce the "short circuit" phenomenon, but increased the power consumption of the hot water pump, at the same time, the hot water circulation pipeline sealing requirements are more stringent.
The rake type vacuum dryer mainly used a baffle type jacket structure in the process of making. In operation, the hot water will enter the jacket from the entrance and will be due to the fixed flow passage. Therefore, no matter the velocity of the hot water, the hot water can flow through every place of the jacket to make the jacket evenly heated; at the same time, the hot water turbulence is added. The flow effect improves the heat transfer efficiency.
The shaft and rake tooth of the rake type vacuum dryer are hollow and can be passed into the heating medium. The surface of the rake can be used as a heat transfer surface. Therefore, the shaft and the rake tooth are called the heat axis. For the large rake type vacuum dryer, the heat transfer area of the hot shaft accounts for more than 60% of the total heat transfer area. The heat transfer effect of the heat transfer directly affects the drying efficiency of the dryer rate. In order to improve the heat transfer effect of the hot shaft, a special heat medium runner is designed in the hot shaft, thus greatly enhancing the heat transfer.