Debrecen. The BMW Group plant in Debrecen is taking shape. The first technology to be put into operation at the new production site in Hungary is the state-of-the-art paint shop. By using various new processes and systems such as power-to-heat, heat grid and eRTO, the plant in Debrecen is the first paint shop in the BMW Group’s global production network that will operate completely without the use of fossil fuels. The new site in Debrecen, where pre-series production of the New Class will start at the end of the year, is a blueprint for all future plants based on the principles of the BMW iFACTORY.
The new paint shop in Debrecen is designed to paint 30 vehicle bodies per hour in a fully automated painting process. This capacity can be significantly expanded later. The facility is equipped with BMW iX1 bodies. The state-of-the-art facility was developed and planned with the help of existing expertise in the production network. The paint shop building offers work space for modern production on a floor area of 33,000 square meters and three floors.
Power-to-Heat significantly reduces the carbon footprint
The key requirement for operating the paint shop in Debrecen without fossil fuels such as natural gas is the power-to-heat principle. All ovens required for the painting process and other processes are operated entirely electrically – instead of with natural gas as was previously the case. This principle significantly reduces the paint shop’s carbon footprint, even if electricity consumption increases due to the lack of natural gas. In Debrecen, we obtain our external electricity requirements for production exclusively from renewable energy sources.
Heat Grid saves another 10 percent energy
The “Heat Grid” energy efficiency project was successfully implemented in the planning of the new paint shop. The innovative concept combines several measures for efficient energy recovery and achieves additional energy savings of up to ten percent. The heart of the project is a large multivalent storage boiler that bundles the waste heat from the compressed air supply, the drying ovens and the refrigeration systems. This waste heat is then used to preheat the water circuit.
The second special feature in Debrecen is that the system works with a water flow temperature of just 65 degrees Celsius, compared to 90 to 120 degrees Celsius in previous systems. The warm water is used to supply the hall ventilation systems in the paint shop and to keep the paint booths stable at a process temperature of 22 degrees Celsius and a humidity of 60 to 65 percent.
Exhaust air purification using the innovative eRTO process
The innovative eRTO process is used in Debrecen to purify the exhaust air. eRTO stands for electrically regenerative thermal oxidation, a process that purifies the exhaust air from the paint shop at temperatures of 800 to 1,000 degrees Celsius and – unlike before – requires only electricity. During the purification process, the exhaust air flows through a ceramic bed in which the remaining solvents are burned. To do this, the air must be heated to a high level in a short time. Thanks to its high thermal recovery rate, which retains the heat in the system, the eRTO system offers very high energy efficiency.
Fully automated dry separation
In the new paint shop in Debrecen, as in many other BMW Group locations, a modern, environmentally friendly dry separation system is used. The paint overspray that does not adhere to the body in the paint booth is filtered out and bound with limestone powder. This significantly reduces water consumption and the paint booth can be operated with up to 90 percent recirculated air. This means that only ten percent of the air needs to be tempered and humidified instead of 100 percent, which leads to high energy savings. In addition, the used stone powder can be returned to the recycling cycle and reused in the cement industry, for example, instead of having to be disposed of as contaminated wastewater as was the case with the previous wet washing process.
Comprehensive digitization
In addition to innovative technologies such as Heat Grid and eRTO, comprehensive digitalization also contributes to the high efficiency of the new paint shop in Debrecen. For example, so-called AGVs (Automated Guided Vehicles) transport the bodyshells driverless and fully automated to the various work steps. In addition, an automated surface inspection (AOI) is used, which uses artificial intelligence to detect irregularities after painting and records the features that require rework. The planning for the paint shop was carried out virtually. This meant that the structural planning could be checked virtually before the actual construction. Introductory training for employees was also carried out virtually in advance.
