Coil box type heating furnace

Abstract

The utility model discloses a coil pipe box type heating furnace which comprises a furnace body, a furnace pipe is arranged in a radiation section of the furnace body, the furnace pipe is of a spiral coiled structure, and the pipe diameter of the furnace pipe is enlarged many times through a connector in the oil flowing direction. Therefore, the vaporization rate of oil is improved, the heating amplitude of the wall of the furnace tube is reduced, the flow velocity of the oil is improved, and the coking rate of the oil is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of petrochemical industry, in particular to a coil box type heating furnace. Background Art

[0002] In my country's petroleum refining industry, most crude oil is heavy. During the refining of heavy oil, the oil in the furnace tube is prone to coking under the high temperature environment of the heating furnace. Coking can cause the furnace tube to overheat, resulting in furnace tube creep or permanent deformation, or even rupture, which can cause serious production accidents.

[0003] Traditional heating furnace tubes are mostly connected by 180° elbows. The pressure drop of oil passing through the tubes is relatively large. Due to this limitation, the designed flow rate of oil in the tubes is often low, which increases the possibility of oil coking. Summary of the invention

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide a coil box type heating furnace, which can improve the volumetric thermal strength of the heating furnace, reduce the coking rate of oil products, and effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a coil box type heating furnace, comprising a furnace body, wherein a furnace tube is arranged inside the radiation section of the furnace body, and the furnace tube is a spirally coiled structure. The furnace tube is connected to a connector to realize multiple expansion of the tube diameter along the flow direction of the oil product.

[0006] As a preferred technical solution of the utility model, the furnace tube is expanded 1 to 4 times.

[0007] As a preferred technical solution of the utility model, the corners of the furnace tubes are connected by 90° elbows, and the curvature radius of the elbows is 3 to 8 times the outer diameter of the furnace tubes.

[0008] As a preferred technical solution of the utility model, the oil flow modes in the radiation section of the furnace body include two types: entering from the upper part of the radiation section and flowing out from the lower part and entering from the lower part of the radiation section and flowing out from the upper part.

[0009] As a preferred technical solution of the utility model, the number of tube passes of the furnace tube is 1 to 4 tube passes.

[0010] As a preferred technical solution of the utility model, the distance between the furnace tube and the inner wall of the furnace body lining is 1.5 to 2 times the outer diameter of the furnace tube.

[0011] As a preferred technical solution of the utility model, the furnace tubes are arranged at equal intervals, and the tube center distance is 1.7 to 2.5 times the outer diameter of the furnace tube.

[0012] Compared with the prior art, the beneficial effects of the utility model are: the coil box-type heating furnace has a compact structure, a reasonable design, and is easy to operate. By gradually expanding the diameter of the furnace tube along the flow direction of the oil, the vaporization rate of the oil can be improved. During the vaporization process, the oil absorbs a large amount of furnace heat without heating up, reducing the temperature rise of the furnace tube wall, thereby reducing the coking rate of the oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0014] Figure 2 for Figure 1 Sectional view at AA in the middle;

[0015] Figure 3 for Figure 1 Sectional view at the middle BB;

[0016] Figure 4 This is a schematic diagram of the structure of Example 2.

[0017] In the figure: 1 furnace body, 2 furnace tube, 3 connector. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments (for the convenience of description and understanding, the following is a schematic diagram of the present invention). Figure 1 Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present utility model.

[0019] Example 1: Please refer to Figure 1-3 The utility model provides a technical solution: a coil box type heating furnace, comprising a furnace body 1, a four-tube furnace tube 2 is arranged inside the radiation section of the furnace body 1, the furnace tube 2 is a spirally coiled structure, the oil enters from the upper end of the furnace tube 2 and flows out from the lower end of the furnace tube 2, the furnace tube 2 is expanded twice along the flow direction of the oil through a connector 3, the connector 3 is a tubular object with one end larger and the other end smaller, adapted to the size of the connected furnace tube 2, and connected to the furnace tube 2 by welding.

[0020] Furthermore, the corners of the furnace tube 2 are connected by 90° elbows, and the curvature radius of the elbows is 3 to 8 times the outer diameter of the furnace tube 2. This arrangement can reduce the pressure drop of the oil, increase the flow rate of the oil in the furnace tube 2, and reduce the coking rate of the oil in the tube.

[0021] Furthermore, the distance between the furnace tube 2 and the inner wall of the lining of the furnace body 1 is 1.5 to 2 times the outer diameter of the furnace tube 2, which can optimize the heat transfer efficiency.

[0022] Furthermore, the furnace tubes 2 are arranged at equal intervals, and the tube center distance is 1.7 to 2.5 times the outer diameter of the furnace tube 2, which can optimize the heat transfer efficiency.

[0023] During use: when the oil passes through the radiation section of the furnace body 1, it enters from the upper end of the furnace tube 2 inside the furnace body 1 and flows out from the lower end. When passing through the spirally coiled furnace tube 2, the pressure drop is reduced, the flow rate is increased, and the oil is prevented from coking in the furnace tube 2; at the same time, the furnace tube 2 closer to the lower end increases the vaporization rate and flow rate of the oil after the diameter is expanded by the connector 3, further reducing the coking rate of the oil in the furnace tube 2.

[0024] Example 2: Figure 4 As shown, the difference from Example 1 is that the lower end of the furnace tube 2 in the furnace body 1 is the oil inlet, the upper end is the oil outlet, and the diameter of the furnace tube 2 gradually increases from bottom to top.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coil box type heating furnace, comprising a furnace body (1), a furnace tube (2) being arranged inside a radiation section of the furnace body (1), the furnace tube (2) being a spirally coiled structure, characterized in that: The furnace tube (2) is expanded in diameter multiple times along the oil flow direction through the connector (3).

2. The coil box type heating furnace according to claim 1, characterized in that: The furnace tube (2) is expanded 1 to 4 times.

3. The coil box type heating furnace according to claim 1, characterized in that: The furnace tube (2) is connected at the corner by a 90° elbow, and the curvature radius of the elbow is 3 to 8 times the outer diameter of the furnace tube (2).

4. The coil box type heating furnace according to claim 1, characterized in that: There are two ways in which the oil product flows in the radiation section of the furnace body (1): entering from the upper part of the radiation section and flowing out from the lower part, and entering from the lower part of the radiation section and flowing out from the upper part.

5. The coil box type heating furnace according to claim 1, characterized in that: The number of tube passes of the furnace tube (2) is 1 to 4 tube passes.

6. The coil box type heating furnace according to claim 1, characterized in that: The distance between the furnace tube (2) and the inner wall of the lining of the furnace body (1) is 1.5 to 2 times the outer diameter of the furnace tube (2).

7. The coil box type heating furnace according to claim 1, characterized in that: The furnace tubes (2) are arranged at equal intervals, and the distance between the tube centers is 1.7 to 2.5 times the outer diameter of the furnace tubes (2).

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