Why the Lößnitz foundry has invested in modern filter technology.
Lößnitz foundry - the filter that can cope with these emissions first had to be invented
The Lößnitz foundry produces tools weighing several tons for Porsche toolmaking and for BMW, Daimler and Volkswagen vehicles. The long-established company is a heavyweight in the industry and an important employer in the region. However, the situation in the middle of the settlement area has recently been tense.
During the casting of the massive tools, the filler material in the large molds evaporates, and the pollution caused by fine dust, soot and odors was high.
In the past, this not only led to conflicts with local residents, but two years ago, measurements by the Saxon State Office for the Environment, Agriculture and Geology showed that the operation caused increased environmental pollution on casting days. Although they were not classified as serious, measures were demanded.
Expansion of production - and elimination of emissions
In 2014, the company decided to increase its production capacity - and to extensively renovate the casting hall in the process. New filter technology was to be installed to separate the large quantities of fine dust, and the focus was also on eliminating gas emissions and unpleasant odors.
Investments were made in modern environmental filter technology and in the optimum supply of clean fresh air for the employees working in the hall. The heat for the temperature control of the supply air during the heating period is recovered from the waste heat of the cupola furnace.
The exhaust gas values are well below the limit values
“In future, the exhaust gas values will be well below the permitted limits,” says Martin Boxhofer, Project Manager at Kappa. He supervised the foundry during the installation of the exhaust gas purification system. “Kappa did pioneering work on the project. Initially, there was no solution, but Kappa was able to design a tailor-made system for us,” says Frank Kattermann, former Managing Director of GL Gießerei Lößnitz GmbH. “A system like this has never existed before in Germany. We are probably even a pioneer in Europe.”
Sand and gravity die casting releases emissions
Sand and gravity die casting releases large quantities of particulate matter and tertiary amines. Until now, solutions for the efficient and economical separation of these emissions have been lacking. Despite the difficult initial situation, GL Gießerei Lößnitz GmbH launched an exhaust air purification project to provide optimum protection for employees, local residents and the environment.
Together with Kappa Filter Systems, a system was developed that separates both emissions - fine dust and odors - highly efficiently and economically. The Kappa Ekon®dedusting system forms the core of the system. It represents a completely new filter system for the separation of industrial dusts. Kappa Ekon® revolutionizes the construction of large dedusting systems by requiring only half as much space as conventional systems. At the same time, it reduces the residual dust content by half and energy consumption by a third.
Casting molds are distributed throughout the hall
The problem was that there was no fixed place in the factory hall where casting could take place and where exhaust fumes could be extracted in a targeted manner. The huge casting molds are distributed throughout the entire hall, the exhaust air collects under the roof and escapes to the outside.
In future, the system developed by Kappa will collect the exhaust gases directly under the hall roof. For this purpose, 17 extraction points have been set up, which circulate a total of 180,000 cubic meters of air per hour. Sensors detect where in the hall casting is currently taking place - the output is automatically optimized at the necessary points.
The polluted hall air is replaced by fresh air. It is preheated to the desired level and diffuses in draught-free along the hall floor. “This means there are no draughts and people have a comfortable workplace,” says Raphael Mülleder, process engineer at Kappa. The system continuously supplies the employees with fresh air; windows and doors can remain closed. The supply air is heated using waste heat recovered from the existing melting furnace.
Glass elements ensure transparency of functions
The extracted air is highly purified by the Kappa Ekon® filter system. This is a large dust extraction system with large glass elements made of highly resistant and solid safety glass in the access areas. This provides a clear view of the clean gas room, which is flooded with light and accessible for maintenance purposes. The cleanliness of the clean gas can therefore be monitored at all times.
An odor-binding reaction agent is fed into the exhaust gas flow upstream of the filter system. The odor binding agent subsequently forms a stable adsorption and reaction layer on the filter surface for further odor separation. In this way, the emission cocktail of smoke, fine dust and odors is highly effectively separated in the Kappa Ekon® before the clean exhaust air is released into the environment.
Results
- The plant expansion was granted thanks to the innovative environmental technology.
- The fine dust values in the exhaust air flow are more than ten times lower.
- Odor emissions are below the required values.
- The system's outstanding energy efficiency reduces energy consumption by around 32 percent compared to conventional solutions.
