Rauch Fruchtsäfte relies on a Bosch steam boiler with air preheating system
Rauch Fruchtsäfte GmbH & Co OG has expanded its process heat supply at the Nüziders location in Austria with a new Bosch steam boiler system. Thanks to its integrated economizer and air preheater (APH), the system operates particularly energy-efficient. The air preheating alone saves up to 41,000 euros in fuel costs annually and reduces the CO2 emissions by 175 tons per year.
The chosen solution also increases the efficiency by two percent, thereby reducing the primary energy consumption and protecting the environment at the same time. Other reasons for the use of a Bosch air preheating system were the low servicing and maintenance expenditure as well as the low investment costs.
The APH air preheating system essentially consists of two heat exchangers. A large part of the heat is extracted from the flue gas in the integrated economizer and is used to heat up the feed water. This results in an efficiency increase of approximately six percent as well as reduced fuel consumption. The flue gas releases its residual heat in the first heat exchanger of the air preheating system. The combustion air is preheated with the waste heat via the second heat exchanger. This additionally reduces the system's consumption.
A further efficiency benefit results from the modulating twin-fuel firing. It burns biogas in mixed operation with natural gas. The biogas is generated from the solid remnants arising from the fruit juice production. The motor speed adapts flexibly to the actual burner output by means of speed control. The result is reduced power consumption and noise-reduced operation. Oxygen control combined with a carbon monoxide probe ensures an optimal fuel-air ratio. It continually records the oxygen level and the unburned components of the flue gas and controls the air supply accordingly. This increases the efficiency of the firing system and reduces the fuel demand.
Bosch's state-of-the-art control systems offer intuitive control and permanently efficient operation: evaluations and analysis by the integrated Condition Monitoring software improve transparency and increase efficiency and availability. The sequence control optimises service life by intelligently switching on and off the pilot and follow-in boiler.
The new Bosch boiler system with a steam capacity of 15,000 kilograms per hour provides efficient and sustainable process steam supply at Rauch Fruchtsäfte in Nüziders. The steam system was brought in and installed by the system installation company, Intemann GmbH from Lauterach. The company ATP architekten ingenieure from Innsbruck was entrusted with the planning of the project.
“The steam boiler was equipped with an air preheating system at the request of Rauch. This component alone increases the efficiency by approximately 2 percent.”