What problems will the vacuum dryer encounter in daily operation?

The so-called vacuum drying is to heat and dry the dry materials under vacuum conditions. If a vacuum pump is used to extract air and moisture, the drying speed will be accelerated. If using a condenser. The solvent in the material can be recovered through the condenser. If the solvent is water, a condenser is not needed, saving energy investment. When the vacuum dryer is operating, solid particles are suspended in the liquid and need to be separated from the slurry at a certain stage. First, mechanical solid-liquid separation equipment, such as filter centrifuges, vacuum filters, settlers, filter presses, and static thickeners, are used to separate solids from liquids. To choose the best type of mechanical separation equipment for a certain process, vacuum dryer technology is mainly determined based on factors such as solid properties, production capacity, and operating methods. However, product quality requirements are usually not achieved through only one mechanical solid-liquid separation step, 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% (weight). Therefore, after 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. Thereby achieving the drying effect.

An important driving force that changes the drying effect of the product is the evaporation temperature of the liquid contained. This temperature of the vacuum dryer depends on the process pressure. Reducing the process pressure to lower the evaporation temperature can bring many benefits, especially for contact drying. There is no need to design a drying system that operates only at low pressures and high allowable temperatures, as this would require large and expensive peripheral equipment. Systems are generally designed as self-regulating pressure vessels. That is, condensers and vacuum units are adapted to handle high steam flows at higher pressures, and the pressure decreases as the drying capacity decreases.