Thermal flue gas cleaning with directly downstream waste heat recovery system
As a general contractor, Birk supplies a ready-to-operate thermal afterburning plant / thermal exhaust air purification plant of a downstream waste heat recovery plant in upright design to a globally operating company in the processing of agricultural raw materials. The post-combustion plant / exhaust air purification plant was designed for a raw gas volume flow of approx. 180 mn³/h of inert exhaust air with 22 kg of harmful gas components from the upstream process plants.
The combustion plant has the latest burner generation of our self-developed industrial combustion plants - for best clean gas values, low energy consumption and high flame stability. In addition, the plant is equipped with a clean gas temperature control which continuously regulates the temperatures of the clean gases to be discharged at a level of approx. 300°C in order to keep the escaping clean gas above the condensation temperature of the critical components contained therein.
In order to meet the equally high requirements of the process-related exhaust gas purification process with regard to the exhaust gas components to be treated, the post-combustion system was designed for increased treatment temperatures, with simultaneous internal condensation protection against aggressive exhaust gas components and reduced surface temperatures. The waste heat utilisation plant is dimensioned for exhaust gas temperatures of approx. 750°C, which makes it possible to recover a considerable heat output of 110kW with the entire clean gas volume flow of the post-combustion plant and the relatively low pollutant gas volume of the upstream process and thus generate hot water of 180°C for feeding into the on-site operating network.
The scope of the heat recovery system also included the entire area of the fully insulated clean gas supply and discharge in the internal exhaust gas system of the thermal afterburning system from the outlet at the combustion chamber via the heat exchanger of the waste heat recovery system back into the clean gas conveying system. The independent exhaust air volume flow control of the heat recovery system is managed and controlled in such a way that there is no influence whatsoever on the upstream afterburning process or on the upstream customer process.
The overall plant consisting of afterburning and waste heat utilisation has been realised in such a way that the individual plant components have been delivered almost ready for operation, i.e. pre-installed electrically and mechanically. The entire control, regulation and monitoring functions of the entire plant are performed by a common central control system based on Siemens S7-300, which is equipped with a user-friendly visualization with touch function.