Analysis of the development problems of vacuum dryer manufacturers

Vacuum dryer has many advantages: when drying under low pressure, the oxygen content is low, which can prevent the oxidative deterioration of the dried material, and can dry flammable and explosive dangerous goods; it can vaporize the moisture in the material at low temperature, and it is easy to dry heat-sensitive materials; It can recover valuable and useful components in the dried material; it can prevent the discharge of toxic and harmful substances in the dried material, and it can become an environmentally friendly green drying. Therefore, the application of vacuum dryers is becoming more and more extensive.
vacuum dryer

The main disadvantage of the vacuum dryer is that it needs a vacuum system capable of pumping water vapor, which makes the investment cost of the equipment high and the operation cost high; the production efficiency of the equipment is low and the output is small.

To overcome these shortcomings, many scientific and technological workers have made many efforts. At the same time, due to the many advantages of vacuum drying, some products have to use vacuum dryers. Therefore, the development of vacuum dryer will be very promising.



The vacuum drying process is a complex, time-varying, and non-linear industrial process. Drying control is to adjust and control the process parameters that affect the entire drying process.

During the synthesis of many chemical and pharmaceutical products (intermediates or final products), solid particles are suspended in a liquid and need to be separated from the slurry at some stage. First, use mechanical solid-liquid separation equipment, such as filter centrifuges, vacuum (or pressure) filters, settlers, filter presses, and static thickeners, to separate solids from liquids.

To select the best type of mechanical separation equipment for a certain process, the vacuum dryer technology is mainly determined by factors such as solid properties, capacity and operation mode. But usually only one mechanical solid-liquid separation step cannot meet the product quality requirements, because it is impossible to remove all the liquid by mechanical force alone. Depending on the product and equipment, the humidity of the product discharged from the centrifuge or filter is generally in the range of 5% to 80% (by weight).

Therefore, after the mechanical solid-liquid separation is completed, it is generally necessary to separate the liquid remaining in the solid through a thermal solid-liquid separation step. This step is commonly referred to as "drying".

An important driver of variation in product drying performance is the evaporation temperature of the contained liquid, which depends on the process pressure.

Lowering the process pressure and lowering the evaporating temperature can bring many benefits, especially for contact drying. There is no need to design an ideal drying system that operates only at the lowest pressure and highest allowable temperature, as this would require large and expensive peripheral equipment. The system is generally designed as a self-regulating pressure vessel.

That is, the condenser and vacuum are adapted to handle high vapor flows at higher pressures, and the pressure decreases as the dry volume decreases.

The vacuum dryer is a device that removes moisture from the parts inside the container by pumping out the air inside the packaging container to reach a predetermined vacuum degree. During the drying process, the inside of the tank is in a vacuum state, and the jacket is heated by hot water (or steam, heat transfer oil). As the tank rotates at a low speed, the material moves up and down in the tank, forming a "diamond track" inside and outside the tank and absorbs evaporation. The steam is continuously discharged through the vacuum pipeline to achieve the purpose of drying the material.

While drying the mixture, built-in spraying, filtering, crushing and other devices according to customer requirements can realize its multi-functional operation.