Application of Ceramic Fiber Modules in Ethylene Cracking Furnaces

Ethylene cracking furnaces are the core equipment in ethylene plants, consuming the most energy and operating under the most demanding conditions.  Their energy consumption typically accounts for more than 60% of the total energy consumption of the entire plant. Under long-term high-temperature, high heat flux density, and frequent start-stop conditions, the furnace lining material must not only possess excellent thermal insulation properties but also be resistant to high temperatures, thermal shock, and maintain structural stability. As cracking furnaces move towards high-load, long-cycle operation, traditional dense refractory materials are no longer able to meet the dual demands of energy saving and reliability. Zirconia-containing ceramic fiber modules, due to their low thermal conductivity, high temperature resistance, and lightweight advantages, have become the mainstream choice for modern ethylene cracking furnace lining systems.

Application Forms of Ceramic Fiber Modules in Cracking Furnaces

In ethylene cracking furnaces, ceramic fibers are typically used in combination with modules, boards, and flexible auxiliary materials in the radiant and convection sections. Zirconia-containing ceramic fiber modules are mainly used for the hot face lining of the furnace roof and walls in the radiant section.  They are installed as a whole using a dedicated anchoring system, forming a well-sealed, freely expanding all-fiber structure that effectively alleviates thermal stress caused by temperature fluctuations. Ceramic fiber modules are often used for the back insulation layer of the radiant section furnace walls and the lining of the convection section. Their high compressive and mechanical strength ensures thermal insulation while providing necessary support for the furnace structure. In addition, ceramic fiber blankets, fiber paper, and fiber textiles are widely used as auxiliary materials for expansion joint filling, anchor insulation, and flexible sealing of various openings to prevent thermal short circuits.

Key Nodes and Process Treatment

In the ceramic fiber module structure, the burner area is one of the most critical and easily failing nodes. Typically, the burner brick and fiber lining are fixed separately, with independent load-bearing achieved through stainless steel components. During installation, approximately 20 mm thick zirconia-containing ceramic fiber blanket is wrapped around the outer surface of the burner brick and fixed with heat-resistant steel wire.  The ceramic fiber module is then used to compress and seal the area, ensuring airtightness and thermal stability at the connection point. To further extend their service life, zirconium-containing fiber modules are typically coated with a high-temperature erosion-resistant coating on their hot surface after installation. This effectively suppresses crystallization and powdering of the fibers under high-speed, high-temperature airflow.

Operation Management and Maintenance Key Points

The long-term reliable operation of ceramic fiber modules depends on standardized use and maintenance management. During operation, the heating and cooling rates during the start-up and shutdown of the cracking furnace should be strictly controlled to avoid local damage to the lining due to excessive temperature differences; at the same time, the expansion joint status should be regularly checked, and cracks or local peeling on the lining surface should be dealt with promptly. For inspection and maintenance, it is recommended to conduct a comprehensive inspection at least once a year, focusing on the sealing condition of module joints, corners, and around the burners, checking the integrity of anchor bolts and changes in lining thickness, and comprehensively assessing the health of the furnace lining based on the temperature distribution of the furnace's outer surface. During construction and maintenance, protective equipment such as dust masks should be worn to prevent fiber dust from affecting personnel.

Application Advantages and Economic Value

The core advantages of zirconium-containing ceramic fiber modules lie in their comprehensive energy-saving effect and structural advantages. Their thermal conductivity is typically only 0.1–0.2 W/(m·K), which can significantly reduce heat loss from the furnace wall and improve the overall thermal efficiency of the cracking furnace; at the same time, ceramic fiber modules are more than 75% lighter than traditional refractory materials, effectively reducing the load on the steel structure, and possess excellent thermal shock resistance, adapting to the frequent operating condition fluctuations of the cracking furnace. The modular installation method also significantly shortens the construction period and reduces downtime. From an economic perspective, ceramic fiber modules not only help reduce fuel consumption and operating costs but also extend the maintenance cycle and improve the stability and reliability of the device's operation.

With their excellent thermal insulation performance, good high-temperature stability, and mature engineering application system, zirconium-containing ceramic fiber modules have become an important technical support for achieving efficient, energy-saving, and long-cycle operation of ethylene cracking furnaces. Through reasonable structural design, standardized construction processes, and scientific operation and maintenance management, the comprehensive advantages of ceramic fiber furnace linings can be fully utilized, providing reliable assurance for the safe, stable, and low-energy consumption operation of ethylene plants.