Many food, pharmaceutical and industrial raw materials are required to be dried to a specific moisture content at a temperature below 100 ° C, rather than being completely dried. How to effectively control the drying process to make the drying material reach a specific moisture content is a problem to be solved. Obviously, if the control process is not accurate, and the moisture content of the dried product exceeds or fails to reach the required moisture content, the product quality will be affected.

Vacuum drying uses the characteristics of boiling point reduction of liquid (water, chemical or biological solvent) at low pressure, which can quickly dry the materials to be dried at room temperature or low temperature, thus realizing the above requirements of drying at low temperature, without damaging the physical, biological and chemical characteristics of the materials to be dried, which is suitable for many applications. However, the current vacuum drying device can not automatically control the moisture content of the material to be dried to the specified target in the drying process, which is mainly because it is difficult to measure the moisture content of the material to be dried in real time and quickly and effectively during the drying process, so it is difficult to accurately control the drying end point.

The current commonly used method of moisture content measurement is to measure the weight or volume change of moisture after it is completely removed from the wet material. However, this method is measured after the drying process, which is suitable for measuring the initial moisture content of the dried material after it is completely dried. If you want to control the drying material to a specific moisture content, the time of drying process is difficult to master. If the monitoring of the drying process is not accurate, the drying time is too long, and too much moisture is removed, so that the dry matter is less than the desired moisture content, the whole drying process must start from scratch, not only wasting raw materials and energy, but also reducing production efficiency. If the drying process is stopped temporarily, the dry matter is sampled, and then the moisture content is measured according to the existing measurement method, the repeated intermittent sampling not only increases many inconveniences, but also interrupts the continuity of the drying process, and it is easy to introduce external error factors in the sampling process, which makes the measurement inaccurate. Moreover, this kind of sampling method is not suitable for vacuum drying device, because the production condition (vacuum degree) of vacuum drying is to be destroyed during sampling. After sampling, the vacuum drying device needs to reach the required vacuum degree again, and then continue the drying process, which is time-consuming and laborious, reducing efficiency. Therefore, this kind of intermittent sampling measurement method is difficult to meet the speed and continuity of vacuum drying. The requirements of transformation.

The intelligent drying equipment measures the parameters, pressure, temperature and volume of the drying system in real time during the drying process. Through the system parameter value and embedded software, the moisture content of the dried material can be measured quickly and in real time, so as to control the drying of the dried material to the target moisture content accurately. The monitoring process is automated without human intervention. Water content measurement range is wide, from the beginning of the drying process to the complete drying can be measured. And meet the requirements of speed and continuity.