How to Ensure the Heat Bearing and Uniform Heat Transfer Effect of the Furnace Shell of Batch-Type Oil Refining Equipment

How to Ensure the Heat Bearing and Uniform Heat Transfer Effect of the Furnace Shell of Batch-Type Oil Refining Equipment

To ensure the heat bearing and uniform heat transfer effect of the furnace shell of batch-type oil refining equipment, targeted optimizations need to be carried out from four dimensions: structural design, heat source adaptation, flow field optimization, and material selection, so as to ensure that heat can be stably borne and uniformly transferred to the reactor vessel body. The specific measures are as follows:

Optimize the Fitted Cavity Structure Design of the Furnace Shell

A uniform gap of 50–100mm must be maintained between the inner wall of the furnace shell and the outer wall of the reactor vessel. This gap can not only ensure the smooth circulation of heating media (high-temperature flue gas or heat transfer oil), but also avoid local flow blockage caused by excessively small gaps or heat loss caused by excessively large gaps. Meanwhile, the entire furnace shell should be designed into a cylindrical structure matching the reactor vessel, ensuring that the heating medium can surround the reactor vessel 360° without dead zones, eliminating "local high-temperature areas" and "heat transfer dead zones" to structurally guarantee heat transfer uniformity.

Add Internal Flow Guiding Structures to Enhance Medium Flow Field Uniformity

Weld spiral flow deflectors or annular flow guide rings inside the furnace shell to guide the heating medium to flow spirally or circularly along the axial direction of the reactor vessel, avoiding medium short-circuiting (i.e., being discharged without sufficient heat exchange). For furnace shells heated by flue gas, the flow deflectors can extend the residence time of flue gas inside the furnace shell and improve heat exchange efficiency. For furnace shells heated by heat transfer oil, the flow guiding structures can break the boundary layer of medium flow and reduce the local temperature difference on the outer wall of the reactor vessel. The flow deflectors should be made of the same high-temperature resistant material as the furnace shell, and the welding joints should be polished to prevent ash accumulation or scaling from affecting the flow field.

Match Heat Source Characteristics to Ensure Stable Heat Bearing

Adjust the furnace liner design according to the type of heating medium:

In the case of flue gas heating, the furnace shell must be precisely connected to the burner, and a baffled flue should be designed to allow high-temperature flue gas to sweep across the outer wall of the reactor vessel multiple times. Meanwhile, control the flue gas flow rate within a reasonable range (usually 2–3m/s) — an excessively high flow rate will shorten the heat exchange time, while an excessively low flow rate is likely to cause local heat accumulation.

In the case of heat transfer oil heating, the furnace shell should be designed into a jacketed structure and equipped with a forced circulation pump to ensure a stable flow rate of heat transfer oil inside the jacket, avoiding excessively high or low local oil temperature and ensuring uniform heat transfer.

Select Furnace Liner Materials with High Temperature Resistance and High Thermal Conductivity

The furnace shell material must balance heat bearing capacity and thermal conductivity. For conventional working conditions, Q245R boiler steel or 304 stainless steel are preferred; these materials can maintain stable structural strength at 600–800℃ and have moderate thermal conductivity. For high-temperature and long-term working conditions, 310S stainless steel should be selected, which has stronger oxidation resistance and can prevent the decline of heat transfer efficiency caused by material oxidation and peeling. In addition, the inner wall of the furnace liner should be derusted and polished to reduce surface roughness and improve the heat transfer efficiency of the heat exchange surface.