Bosch steam boiler system cleverly combined with solar heat

An increase in production capacity provided Fixkraft Futtermittel GmbH, a producer of animal feed based in the Danube port town of Enns, Austria, with the opportunity to restructure its energy supply. A system concept from plant construction company Ing. Aigner Wasser - Wärme - Umwelt GmbH in Neuhofen/Krems, Austria was introduced. It comprises a Bosch steam boiler featuring modules for increased efficiency combined with a solar thermal system. With the new energy supply, Fixkraft is able to reduce its CO2 emissions by around 85 tons per year and make energy cost savings of approximately 15 per cent compared against the old system. The Universal UL-S steam boiler from Bosch with an output of 2,500 kg/h provides the process heat required to produce the animal feed. The saturated steam is introduced directly into the product, meaning that the amount of condensate that is returned is very low. A solar thermal system with an installed collector area of 320 m² is used to help preheat the feed water. The fresh water needed is taken from the companys own well, treated and then supplied to a 6,000-litre heat storage tank. The solar collectors absorb the suns energy and pass it on to the water in the heat storage tank via a heat exchanger. The WSM-V water service module deaerates the make-up water. It is heated to 103 °C. The gases contained in the water dissolve and leave the deaeration system with a small quantity of steam, known as exhaust vapour. The VC vapour cooler uses the thermal energy contained in the exhaust vapour and feeds it back to the water service module. Heating-up steam is saved and the energy efficiency of the system increased. The feed water itself is heated further in the economiser, reducing the flue gas temperature of the boiler. In order to make additional use of the flue gas condensate, a condensing heat exchanger made of stainless steel is installed downstream of the economiser. The make-up water preheated by solar heat absorbs the condensation heat before it is supplied to the feed water tank via the exhaust vapour heat exchanger and deaerator dome. The boiler equipment also includes the low-emission natural gas firing system with oxygen control. This continually measures the oxygen content in the flue gas and controls the air supply accordingly. Modern touchscreen controls with a teleservice connection enable the system to be operated reliably and based on individual requirements. Thanks to the use of solar energy and heat recovery facilities, Fixkraft benefits from a highly efficient and environmentally-friendly steam supply. Energy use is reduced and efficiency increased.

Efficient operation with modular Bosch technology

Following an energy analysis in 2012, Valenzi GmbH & Co. KG from Suderburg in the Lower Saxony region of Germany decided to replace its steam supply. A state-of-the-art, complete system from Bosch was installed. Through this investment, the manufacturer of preserved wild berries anticipates making annual energy savings of around 40,000 euro. It also cuts its CO2 emissions by approximately 300 tons. The existing boilers had been in operation for up to 31 years and were replaced with two modern UL-S type steam boilers with speed-controlled natural gas firing systems, each with an output of 5,000 kg/h. The company primarily uses steam to preserve mushrooms and refine wild berries and soup ingredients. The second boiler is used as a backup and to cover peak loads. The modular design of the Bosch system ensures energy-optimised boiler operation. Integrated economisers make efficient use of the energy from the hot boiler flue gases to heat the feed water. The efficiency of the system increases by 4.8 per cent and fuel consumption decreases by the same proportion. Water treatment components provide optimum feed water quality. Softened make-up water is produced in the WTM softening system. To reduce susceptibility to corrosion, thermal deaeration is performed after the softening process via the WSM-V water service module. Using the compact EHB heat recovery module, thermal energy from the hot desalted water is used to preheat the feed water. This leads to an increase in efficiency and a reduction in fuel, cooling water and waste water costs. In addition, the system is fitted with a CSM condensate service module. The module collects and stores accumulated condensate and channels it back to the water treatment system. The lower demand for make-up water reduces water and energy consumption. The intuitive touchscreen BCO/SCO controls make it easy to operate and adjust the boilers and system. Triggered by the push of a button or an external request signal, the start-up and shut-down processes for the steam boilers are performed automatically using the integrated SUC start-up, standby and shut-down control. The sequence control applies the consumption-optimised operating mode for the multi-boiler system. The system is kept warm by means of a heating coil that is built into the boiler end. This ensures the rapid availability of the steam boilers. The modular design of the Bosch boilers and components meant that effort for planning and installation could be kept low. Planning office Westfalia Wärmetechnik from Rödinghausen and plant construction company AME-Technik from Hamelin were commissioned to complete this work. The operator benefits from the increased degree of automation of the economically and ecologically optimised energy generation system. In addition to the new boiler system, further measures such as waste heat utilisation in the compressors and cold stores improve Valenzis energy consumption further.