Hot Blast Stoves for Blast Furnaces

The hot blast stoves for blast furnaces by Primetals Technologies exemplify a century of expertise in designing, building, and commissioning hot blast stove plants. This remarkable longevity underscores the ability of the company to adapt and innovate in response to the evolving needs of the iron and steel industry. Experts from Primetals Technologies understand the critical role that hot blast stoves play in the steelmaking process; they ensure superior performance, efficiency, and reliability. Recent projects have focused on integrating a fourth hot blast stove into existing plant infrastructure, enhancing combustion performance and optimizing overall efficiency.

Understanding the intricacies of hot blast stove performance is crucial for optimizing blast furnace operations. Primetals Technologies conducts comprehensive studies and analysis of hot blast stoves to identify opportunities for improvement and innovation. These studies encompass various aspects, including thermal efficiency, structural integrity, and operational reliability, offering actionable insights to improve processes.

In addition to designing new hot blast stoves, Primetals Technologies provides comprehensive repair services to maintain the optimal operation of existing stoves. The company's skilled engineers and technicians are adept at diagnosing and repairing a wide range of issues, ensuring minimal downtime and maximum productivity for operations. Whether it's routine maintenance or emergency repairs, clients can count on Primetals Technologies to provide prompt and effective solutions.

Primetals Technologies possesses considerable experience and expertise in various hot blast stove designs, gained through numerous projects, comprehensive studies, and global collaborations. With over 200 hot blast stove system installations in the past 20 years, Primetals Technologies has built an extensive portfolio that enables the delivery of optimized hot blast stoves. These systems are designed to minimize overall fuel consumption and stove emissions, resulting in highly energy-efficient operations.

Hot Blast Stove Designs

Hot blast stoves have several design types, each with unique characteristics.

Internal Combustion Chamber Stoves

This hot blast stove consists of two chambers, combustion and chequer, which are separated by a dividing wall within a single vessel. The combustion chamber contains the stove burner whilst the chequer chamber is filled with heat storage bricks.

Benefits of Internal Combustion Chamber Stoves

• A novel dividing wall designed to avoid gas short circuiting, along with a catenary (“mushroom”) dome to allow independent expansion of the dome and ring walls’ refractory
• Low energy loss with designs for reduced shell temperature
• Alternative designs for existing hemispherical domes
• Side-by-side gas and air entry ceramic burner lowers the interface distance with the hot blast outlet, avoiding damage to the burner crown and ensuring good combustion efficiency throughout the burner’s life.
• Adaptable for mechanical burners

External combustion chamber stoves

This hot blast stove consists of two separate vessels for combustion and chequer. The two vessels are connected by a crossover at the top of the stove.

Benefits of external combustion chamber-stoves

• Primetals Technologies has enhanced the technology, especially in the crossover area, to avoid gas leaks and hot spots.
• Ability to surpass the size limitation of the internal combustion stove, which is limited by the dome diameter and dividing wall designs.
• Side-by-side gas and air entry ceramic burner lowers the interface distance with the hot blast outlet, avoiding damage to the burner crown and ensuring good combustion efficiency throughout the burner’s life.

Top-fired stoves

This hot blast stove consists of a single vessel with chequer heat storage bricks in the lower section and a ceramic burner in the upper section.

Benefits of top-fired stoves

• Catenary dome to allow independent expansion of the dome and ring walls’ refractory
• Stable burner operation with no pulsations, unlike many top-fired designs–leading to a long life with high combustion efficiency
• Utilization of high heating surface area chequers to optimize the stove size and cost
• Regular hot blast temperature > 1300°C minimizes the blast furnace fuel rate
• A lower dome-blast temperature delta can be achieved, requiring less costly enrichment gas
• Thermal efficiency is generally higher than any other stove designs
• Reduced NO_X emissions