Encopanel: Heat Retention Technology for Hot Strip Mills

The Encopanel® technology is a heat retention system designed for use in hot strip mills. It helps maintain the appropriate temperature of the transfer bar, resulting in more uniform material properties, better surface quality of the product, and improved plant energy efficiency.

In hot strip mills, the transfer bar loses heat through conduction, convection, and radiation as it moves from the roughing mill to the finishing mill, along the transfer table. To compensate for this heat loss, mill operators increase the discharge temperature of the slab from the reheat furnace. Encopanels reduce the need to do this.

Operating the Furnace in this Manner Has Several Impacts

• Longer hold times are required in the furnace, which reduces the mill's overall throughput.
• More energy is consumed to achieve higher discharge temperatures
• The furnace operates continuously at maximum temperature.
• Slab to coil transfer costs are higher.

Features: Encopanel® System: Enhancing Thermal Efficiency in Hot Strip Mills

The Encopanel® system, designed to create a thermal tunnel, consists of several modules. Each module is typically 4.5 meters in length and is lined with top, bottom, and side Encopanel cells that re-radiate the usually lost heat back to the transfer bar. The system's features are specifically designed to maximize energy efficiency and ensure a high-quality transfer bar and final product.

Advanced Insulation Materials

The Encopanel® cells are engineered for maximum heat storage and return, consisting of a complex arrangement of layers. These include insulating ceramic fibers, a unique alloy membrane on the hot face, and a heat-resistant external backing. As the system retains heat that would otherwise be lost, no additional operational energy is required to run the Encopanel system.

Modular Design

The design features all replaceable cells per module, enabling quick and easy maintenance. This minimizes downtime, ensuring the system runs efficiently and reduces the mill's energy inefficiency.

Operational Features of the Heat Retention System

• Opening and closing top lids: these provide safe and easy access for maintenance, preventing damage to the cells from malformed transfer bars.
• Scale clearing bottom panels: these are designed to clear the oxide build-up that falls from the transfer bar, ensuring that the bottom cells remain clean for effective performance.
• Cobble removal system: the Encopanel ® system can include hydraulic pushers or accommodate existing cobble removal methods.
• Knockdown protection unit: This ensures a smooth entry of the transfer bar into the system, preventing damage to the panels.

These features combine to create an efficient and adaptable system that addresses the challenges of heat retention in hot strip mills, offering both operational convenience and long-term reliability.

Encopanel® Spares & Services

Encopanel® cells in mills experience wear due to thermal cycles. To maintain optimal performance, regular assessments are recommended to ensure maximum performance.

Primetals Technologies provides service visits to:

• Evaluate system performance and panel condition
• Advise on panel rotation to optimize maintenance budgets
• Identify cells needing replacement due to wear

Routine evaluations ensure the Encopanel® performs optimally. Primetals Technologies offers a full range of spare parts for the system, including protective components, hydraulic cylinders, and genuine replacement Encopanel® cells.

Benefits of the Encopanel® Heat Retention System for Hot Strip Mills

By improving heat retention, the Encopanel® system offers several benefits that enhance hot strip mill performance:

• Lower reheat furnace temperatures: the Encopanel® system reduces heat loss, allowing the reheating furnace to operate more efficiently and consume less energy. This lowers overall operational costs and enhances the environmental credentials of the mill.
• Increased mill throughput: with Encopanel® heat retention, the transfer bar maintains its optimal processing temperature and improved thermography from head to tail. This enables faster and more efficient processing in both the roughing and finishing mills, increasing overall throughput.
• Expanded product capabilities: the system improves temperature control, allowing the production of a broader range of steel products with varying thicknesses and properties, helping mills reach new markets.
• Higher yield and reduced scrap: by maintaining an even temperature across the length and width during transfer, the Encopanel® system reduces defects such as edge cracking and minimizes head and tail scrap at the crop shear, improving both mill efficiency and profitability.
• Better material consistency: the system ensures a more consistent temperature between the center and the surface, resulting in more uniform geometry during rolling. This leads to consistent material properties and higher-quality steel products.