Special dryer for plaster, resistant to dust generation and deformations.

Most drying rooms on traditional gypsum production lines are coal-fired rooms. These reach higher temperatures and require more intervention from operators.

The gypsum line is manufactured by mixing water and additives with gypsum powder. This process requires a high water content, and to achieve this, strict humidity control, specific temperature and adequate air volume are necessary. Dehumidification must be carried out quickly, and the temperature, especially in the final stages, must not be too high to prevent the gypsum from becoming sandy. If temperature and humidity are not managed correctly, product deformation can occur. During drying, the gypsum lines are hung individually; therefore, the air volume cannot be excessive to avoid damage from impacts between them. TROCKNNER developed the first set of dedicated dehumidification dryers for gypsum lines based on the product characteristics of gypsum lines. It has been continuously optimized and adjusted.

TROCKNNER plaster line dryers are classified into two main types. The first is a room type dryer designed for small and medium-sized plaster moulding manufacturing companies. The mouldings are hung up high in the room before drying. Once the plaster is completely dry, it is ideal for small and medium-sized moulding drying projects, and the initial investment for setting up the room is moderate. Tunnel type dryers have now been developed: the plaster moulding is suspended on a carriage inside the tunnel, and the wet load enters at one end while it exits dry at the other. This reduces the labour required to hang the mouldings and also significantly reduces drying time.

The TROCKNNER special plaster dryer features a closed-loop dehumidification system. This design allows heat to be generated from the moisture contained in the material inside the drying chamber, making it less dependent on external temperatures. This way, it can operate efficiently in cold environments such as in southern areas with low temperatures. The entire drying process takes about 17 hours, reducing the standard time by 7 hours. This performance has far exceeded customer expectations. According to the meter reading, the dryer uses a total of 847 kWh. The average drying cost per plaster line is 60 CLP. The energy expenditure is practically the same as that of previous installations with coal-fired systems. However, in terms of labour investment, it represents a significant saving in labour and costs, especially since coal-fired drying required a specialised operator.

The customer commented that the coal-fired boilers reached very high temperatures and explained that if the temperature or time was not properly controlled in the final stages of gypsum drying, the gypsum could turn to dust as it exited the air, resulting in many defective products. However, he stressed that the problem has been effectively solved with the closed-loop dehumidification heat pump drying system and low-temperature dehumidification functionality, which has significantly improved product quality.