Design of Blast Furnace Gas System
Introduction
Blast furnace gas (BFG) is a combustible by-product of the blast furnace process and has traditionally been used extensively in steel-making plants as an energy source. BFG is generated in large amounts, typically at around 750–1500 Nm3/ton of pig iron produced, and has a low heating value of around 4–5 MJ/m3. This low calorific value of BFG means that it is difficult to use as a direct fuel in furnaces, boilers and generating turbine.
This article discusses the design of Blast Furnace Gas (BFG) systems which take advantage of the low calorific value of this combustible material in order to generate energy. It includes an overview of the various components involved, the designing process, safety considerations and the various techniques for controlling and optimising the system.
Design of BFG Systems
The main components of a BFG system are the furnace, the reaction chambers, the collection points, the distribution system and the associated burners. The furnace serves as the main generating and burning center of the system, and must be constructed and insulated according to safety requirements in order to minimise the risks of accidental fires or explosions. The reaction chambers and pipe system serve to capture and transport the BFG to the burning sites in order to combust and release energy. The distribution system and burners are used to direct the combustible gas to where it can be used safely, usually involving turbogenerators which can use the heat to drive steam to create mechanical or electrical energy.
When constructing and designing BFG systems, care must be taken to ensure that all components are properly sized and insulated accurately. The walls of the furnace and reaction chambers must meet the required specifications in order to prevent potential risks of fires or explosions. Furthermore, burning systems and safety devices must be appropriately located, and the entire design should be reviewed by safety experts and engineers to ensure optimum safety.
Furthermore, the optimal level of pressure for the system must be determined, and the converters should be appropriately proportioned and sized according to the system’s spray and pressure capabilities. Temperature fluctuations should also be taken into account, and the temperature limit should be set in accordance with the temperature of the furnace.
Safety and Control
When designing and constructing BFG systems, safety must be the priority. Support systems and safety measures should be implemented in order to prevent potential accidents and the risk of fires or explosions. Ignition systems, emergency shut off valves and emergency power sources should be installed on furnace systems, and pressure relief valves should be installed to control the system pressure.
Furthermore, appropriate monitoring and control systems must be implemented in order to ensure proper functioning and prevent potential risks. Automated systems should be installed to shut down and/or control the system in case of emergencies, such as a decrease in furnace temperature. Additionally, temperature, pressure and flow monitors should be installed to ensure that the system remains within safety limits.
Conclusion
Blast Furnace Gas (BFG) systems can be effective in harnessing the low calorific value of this combustible material in order to generate energy. Designing and constructing such systems requires careful consideration given to component sizing and insulation, as well as incorporating numerous safety measures in order to prevent potential fires or explosions. Additionally, appropriate control and monitoring systems should be installed in order to ensure the safe operation of the system and prevent potential risks.
