Technical Description of the Furnace Liner for Batch-Type Oil Refining Equipment

Technical Description of the Furnace Liner for Batch-Type Oil Refining Equipment

As the core component of the heating cavity outside the reactor vessel, the furnace liner can also be understood as the heating jacket of the reactor vessel. Its function is to carry heating media (such as heat transfer oil and high-temperature flue gas) and uniformly transfer heat to the reactor vessel body, providing a stable high-temperature environment for pyrolysis reactions. It serves as the key hub for heat transfer in the equipment.

Core Functions and Roles

1. Heat Bearing and Uniform Transfer

High-temperature heat sources (typically high-temperature flue gas generated by fuel combustion or circulating heat transfer oil) are introduced into the furnace liner. The cavity structure of the furnace liner must be designed to fit the outer wall of the reactor vessel, allowing the heat source to fully and evenly surround the reactor vessel. This prevents local overheating or uneven heat distribution, and ensures consistent pyrolysis of materials inside the reactor vessel.

2. Thermal Insulation and Energy Consumption Reduction

A thermal insulation layer is usually installed on the outer side of the furnace liner to reduce heat loss to the surrounding environment and improve heat utilization efficiency. Meanwhile, the furnace liner itself must have good heat resistance to prevent direct erosion of the external equipment structure by high-temperature heat sources, thus playing a dual role of protection and thermal insulation.

3. Adaptation to Combustion System and Safe Operation Guarantee

In the case of direct-fired heating, the furnace liner must be precisely connected to the burner, and be designed with reasonable flue gas flow channels (such as baffled flue) to extend the contact time between high-temperature flue gas and the reactor vessel and enhance heat exchange efficiency. In addition, flue gas outlets and ash cleaning ports are reserved to facilitate later maintenance and prevent ash accumulation from affecting heat exchange performance.

Key Design and Material Requirements

1. Material Selection

The furnace liner operates in a high-temperature flue gas environment of 600–800℃ for a long time, so it must be made of materials with excellent high-temperature resistance and oxidation resistance:

For conventional working conditions, Q245R (boiler-special carbon steel) or 304 stainless steel are preferred, which have good heat resistance and formability at a moderate cost.

For high-temperature and long-term working conditions, 310S stainless steel can be selected, which has stronger oxidation resistance, can withstand higher temperatures and is not prone to deformation.

2. Structural Design Points

Fitted Cavity Structure: A reasonable gap (usually 50–100mm) must be maintained between the inner wall of the furnace liner and the outer wall of the reactor vessel, which ensures the circulation of heat source while avoiding local heat exchange dead zones.

Flue Gas Diversion Structure: Diversion plates are added inside to guide the uniform axial flow of high-temperature flue gas along the reactor vessel, improving heat exchange efficiency.

Sealing and Interface Design: High-temperature resistant seals are adopted at the joints between the furnace liner and the burner as well as the flue to prevent flue gas leakage. Meanwhile, access ports are reserved to facilitate regular inspection and carbon deposit cleaning.