Optimising the operating costs that arise as part of the life cycle costs of a system has been something that Scheuch has focused on for years. Increasingly, energy considerations – that is, saving energy, minimising its usage and recovering it – have become one of the biggest drivers in these endeavours. The result is a new concept for using waste heat in clinker cooler dedusting.
The LEUBE GmbH cement plant invested 31 million euros in modernising clinker production at its Gartenau/St. Leonhard site in Austria. As part of this, Scheuch was responsible for delivering a dedusting plant that incorporated the new waste heat usage concept. In the future, the air/oil heat exchanger will make available 1.3 MW of heat that would otherwise go to waste, and this can be used for preheating heavy oil and room heating.
The concept uses an EMC filter for approximately 150,000 Bm³/h, an air/air heat exchanger for cooling exhaust gas to a maximum of 130°C, and an air/oil heat exchanger for transferring heat from cooling air to the thermal oil circuit.
Project manager Klaus Czepl appraised the new installation and the benefits of heat extraction: "Even after just a few weeks in operation, we know that the cooling system is running extremely smoothly with the heat extraction facilities, and we have calculated a heat quantity of around 1.3 MW that we're able to recover. As things are getting up and running, we are currently using round 800 kW for preheating heavy oil. We are still adapting the system for building heating purposes. Although we have used half of the heat quantity so far, the total additional costs for the heat extraction facilities will be recouped in well under a year. In the clinker manufacturing process, the fact that the dedusting plant – that is, the cooler and the EMC filter plant – does not cause any pressure fluctuations is a real advantage. The differential pressure behaviour is very steady – in fact, it hasn't changed at all, and that makes the furnace end pressure very easy to regulate. We are extremely happy with both the technical concept and the system's performance."