Dürr software module optimizes supply air control in paint booths

Supply air systems are indispensable in paint booths in the automotive industry, as the right temperature and humidity are crucial for high-quality surface coating. In addition, air supply systems ensure comfortable working conditions and safe storage of paints. However, they are also one of the biggest energy consumers in paint shops - air conditioning is so energy-intensive because the incoming outside air has to be continuously treated. "Around a third of the total energy consumption of a paint shop is currently attributable to air conditioning. In order to reduce this high proportion, Dürr has developed an intelligent control system with the further development of DXQequipment.analytics, with which operators can operate the supply air systems in an energy and operating cost-optimized manner for the first time," says Jens Häcker, Vice President Digital Factory at Dürr.

More flexible temperature and humidity control in paint booths

Smart AC calculates an energy-optimized range for the temperature and humidity individually for the respective system and site climate. The minimum and maximum values form the limits of the setpoint range, which the system operator sees on a screen as a so-called control window. The larger the window, the less energy is required to regulate the heating and cooling capacity as well as the water input. Until now, supply air systems have generally been set to fixed setpoints that maintain the greatest possible distance from the critical limit values for the paint application. This often results in more heating or cooling than necessary. "With an optimized control strategy, our digital solution creates the technical prerequisite for controlling supply air systems quickly and precisely within a defined range. For example, instead of using a lot of energy to control 23°C as a fixed point value, the temperature can be flexibly set between 21°C and 25°C. This reduces consumption while maintaining the same high coating quality," explains Jens Häcker.

High energy cost savings possible with supply air systems

An intuitive user interface gives operators an insight into all relevant data in real time, making the processes transparent throughout. The current consumption values of the conditioning modules, the setpoints and trends for cabin conditions, the control options and a comparison of the energy consumption of the window control compared to the previous point control are shown in detail in an overview. The scope is illustrated by an example with the following assumptions: The capacity of an air supply system for base coat and clear coat lines is 350,000 m3/h. The plant requires 80 % recirculated air and there are 30 % critical days with weather fluctuations to which it is necessary to react quickly. Almost irrespective of the location, the annual energy costs for the flexible window were around 30,000 euros lower. The more expensive the energy and the warmer and more humid the climate at the respective location, the greater the savings. Advanced Analytics Smart AC is a new module of the DXQequipment.analytics software developed by Dürr, which records, evaluates and visualizes robot and process data. Smart AC can be integrated into new and existing systems in order to operate supply air systems more sustainably.