Schmitz-Werke, Emsdetten, Germany

Concept for heat recovery from the tenter frame


Schmitz-Werke manufactures high-quality decorative and upholstery fabrics and awning fabrics as well as finished awnings in an in-house metal working department and sewing shop. Creative decorative and upholstery fabrics, curtains, and outdoor textiles complete the product range offered by the family run business in Emsdetten, Germany with around 800 employees. In 2000, Schmitz-Werke introduced an integrated management system for quality, environmental protection, and industrial safety. The company is committed to sustainable development, and as a member of the association 'future e. V.' champions eco-oriented products and services.

Schmitz-Werke, Emsdetten, Germany


An energy solution was developed to include a concept for a heat recovery system, which optimizes use of the post-combustion unit’s exhaust air energy. The heat recovery system was evaluated with regard to its energy efficiency, economic, and ecological impact and technical feasibility. The aim was to optimally exploit the fuel used for thermal post-combustion of the exhaust air and minimize heat losses.


Siemens developed a heat recovery system, which optimizes use of the post-combustion unit’s exhaust air energy. It utilizes the energy previously dissipated into the environment for preheating the cold incoming air by mixing it with the hot exhaust air in an air/air heat exchanger. The preheated incoming air is then blown into the tenter frame, thereby reducing energy losses and fuel consumption.

Siemens developed a mathematical system of equations, which simulates the tenter frame’s process and makes it possible to calculate all fabric and energy flows in order to identify the potential energy savings. The dimensions of the air/air heat exchanger were calculated using simulations, after which Siemens investigated the technical feasibility of the modernization measures in close cooperation with system manufacturers.


The potential offered by the process-related volumes of exhaust air is fully utilized, making production as energy-efficient as possible. As different process conditions affect the level of savings, however, Siemens made it possible to analyze the parameters with the simulation model for tenter frame processes. It was thus possible to calculate and analyze the savings potential for various different processes.


  • Fuel savings of up to 25 percent

  • Corresponding cost reduction

  • Increased cost efficiency

  • Avoidance of emissions

  • Knowledge and transparency of the process