SACMI-Riedhammer Tableware Kilns for Today’s Demands of Quality, Efficiency and Lower Environmental Impact

Riedhammer/DE tableware kilns are designed to the latest, most exacting energy-saving, consumption and emissions specifications. A cutting-edge approach to tableware manufacturing, with technology that’s ready for the fuels of the future. In modern tableware manufacturing, cutting consumption and emissions is the #1 priority. More specifically, regulations that aim to reduce emissions of greenhouse gases, especially CO₂ (such as carbon taxes and green certificates), are becoming stricter and more commonplace. This means higher costs for companies that rely on fossil fuels, usually natural gas, to fire their products. For technology providers, the challenge of reducing gas consumption while optimizing the quality and efficiency of the firing process has been a priority for many years. Renowned worldwide, Riedhammer tableware kilns are designed according to the very latest energy-saving, consumption and, therefore, emissions-reduction specifications.

Preheating of combustion air

Riedhammer tableware kilns are designed to incorporate the specially developed EMS (Energy Management System), a state-of-the-art system for retrieving filtered waste air and sending it to the combustion system at a temperature of 200 °C. The result? Huge energy savings on the kiln. These savings become even more significant on the top-of-the-range EMS 400, which can take retrieved air temperatures all the way up to 400 °C. Designed for standard kilns operating at 1250 °C, this solution is – in the case of porcelain glost firing (at > 1300 °C) – accompanied by a recovery system consisting of silicon carbide (SiSiC) pipes installed under the kiln base at the start of the cooling zone. This latter system allows air to be channeled to the burner zone at a temperature of 400 °C.

Automatic atmosphere control

Riedhammer designs and produces a wide range of roller and tunnel kilns for various applications (biscuit, glaze, decoration), ensuring optimized body management. In terms of control – crucial for attaining higher product quality and further optimizing firing process performance – Riedhammer provides an automatic atmosphere adjustment system, designed for products that require specific atmospheres. One such case is the glost firing of porcelain, which requires maintenance of an in-kiln reduction atmosphere. Without automatic atmosphere control, this result is generally achieved by keeping CO₂ content inside the kiln above 2 %. All Riedhammer kilns for firing in a reduction atmosphere are, instead, equipped with a Lambda probe that ensures optimization of the air-gas mix, thus keeping CO₂ values at the minimum necessary level (0,5–1 %) and saving fuel.

Tailor-made solutions

Riedhammer offers comprehensive firing control solutions for any tableware product: these have applications in single firing, include reduction kilns for porcelain and can also be used for stoneware, vitreous China and items that require special atmospheres, such as bone China (for the latter, special machines with combi gas and electric heating or innovative radiative burners have also been developed). Innovative internal linings with high grade insulation fire bricks and low thermal mass back insulation help boost the reliability of the machine under all manufacturing conditions, thus limiting waste and improving process quality. Additionally, Riedhammer takes a modular approach to kiln design, ensuring machines are configured and customized according to customers’ real needs. For example, development of fixed- or modulated-air combustion adjustment systems, patented burners and sensors for measuring the oxygen content/atmosphere inside the kiln means manufacturers can optimize parameters at all times.

Ready for the future

Cutting-edge Riedhammer solutions for optimizing tableware kiln consumption provide fuel savings of 7–15 % (depending on the specific application and the combined use of different systems). From a decarbonization perspective, one of the options that industry players are beginning to focus their attention on is the replacement of gas (a fossil fuel) with gas-hydrogen mixtures. At Riedhammer, this is already happening, as the latest kilns can operate with mixtures containing up to 20 % hydrogen. As the wider infrastructure develops (“green” hydrogen is currently available only in limited quantities, although several pilot plants have now been built) Riedhammer will focus on designing kilns that can run on ever-higher percentages of hydrogen by making modifications that take into account the lower calorific value of this fuel.

Existing kilns, a further opportunity

Another key area concerns the revamping-modernization of existing kilns. Energy-saving technology may well have progressed enormously, but many companies in the industry have machine pools that are over 20 years old and have no such features. To offset ever-higher fuel costs – and the increasingly strict regulations that penalize CO₂ emissions – companies can contact Riedhammer to assess a range of options. These include replacing existing burners with more modern, efficient models (which operate at higher temperatures) and replacing the combustion air piping with larger-diameter pipes that provide higher flow rates. Lastly, manufacturers can also upgrade the control systems (air regulation), the fans or install indirect cooling systems. In addition to the necessary technological know-how, SACMI-Riedhammer guarantees compliance with safety standards (EN 746), which must be observed in the event of any modifications to the firing system. This is achieved in various ways, such as via the installation of two safety valves on the gas piping that leads to each burner, thus preventing any problems that might stem from malfunctions on the burner itself or the gas feed system, changes to the combustion air, gas leaks or electrical faults. The result is that customers always get the very most from their investment in either new Riedhammer kilns or the modernization of existing machines.