Vacuum drying wood is one of the highest quality types of drying.
The small loading volumes make it easy to load the camera, and the high drying speed makes it possible to achieve high volumes of dried wood. The press effect ensures the stability of the timber geometry and prevents wood cracking and warping.
The mobility of the camera provides the possibility of organizing drying production in a new place at great cost. All that is required is a heated room, electricity, and condensation.
The principle of operation of the Polma press-vacuum drying chambers
The boards are stacked inside the chamber with layers, alternating with aluminum heating plates. The water pump circulates hot water inside the plates. The water is heated by the boiler and the vacuum inside the chamber is created by a liquid vacuum pump. When creating a vacuum, the rubber membrane under the influence of atmospheric pressure presses the stack of boards to the floor of the chamber with a pressure of up to 9500 kg / m2. Thus, the drying of the wood takes place in a vacuum under pressure. With this method of drying the wood is not deformed, but on the contrary is leveled.
The process of heat exchange between the plate and the wood becomes more efficient due to the pressure created. In fact, the pressure promotes high heat loss without loss and allows more water to evaporate. Obviously, increasing the drying rate significantly reduces energy consumption.
In addition, the temperature in the press vacuum chamber is much lower than in conventional dryers, so neither the color of the wood nor its strength change