Thermax’s innovative boiler design enables a steel industry to maximise efficiency with low-calorific-value fuels

Project overview

A steel manufacturer in eastern India required a dependable steam generation solution capable of operating on low-calorific industrial gases, while managing fuel impurities and meeting stringent environmental norms.

Thermax partnered with the customer to develop an engineered approach that ensured stable combustion, operational flexibility, and regulatory compliance. The project enabled reliable steam generation, improved efficiency, and supported the customer’s sustainability objectives under demanding operating conditions.

Challenges

A steel/ferrous industry in Odisha required the development of a boiler capable of efficiently combusting low-calorific-value blast furnace gas (BFG) while ensuring uninterrupted steam generation. In addition to the fuel’s low energy content, it contained significant impurities such as dust, tar, and sulphur compounds, which posed challenges for combustion stability and equipment life. At the same time, the solution had to comply with stringent environmental regulations governing NOx, SOx, and CO₂ emissions, making it a complex and demanding assignment.

Solution

Thermax addressed the challenge by delivering a 205 TPH lean gas-fired boiler designed to operate on BFG, coke oven gas, and gasification oil. The boiler was engineered with a pressure of 105 Kg/cm²g and an outlet steam temperature of 540°C. The scope of work covered complete design, manufacturing, supply, transportation, erection, and commissioning. To ensure long-term reliability and efficiency, several design innovations were introduced. • A low volumetric heat release rate was achieved through a larger furnace, allowing sufficient residence time for complete combustion while enhancing the life of the boiler’s pressure parts. • Refractory lining was applied within the furnace to maintain the temperatures necessary for stable BFG combustion. • A high-efficiency, in-house designed burner was incorporated to optimise fuel utilisation. • In addition, the system was designed to handle a flexible load range of 30 to 100 per cent without requiring support fuel, ensuring consistent performance even while firing lean gases.

Result

The project resulted in a robust and sustainable solution that effectively addressed the challenges of firing low-calorific-value BFG. The boiler consistently delivered the required steam output while maintaining compliance with environmental standards. By efficiently handling impurities and operating across a wide load range without auxiliary fuel, the system provided reliable performance, improved operational efficiency, and reduced emissions. The outcome was a long-term, cost-effective solution that strengthened sustainability while ensuring dependable energy generation.

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