Raw material preheater for extractive distillation of coking pure benzene

Abstract

The utility model relates to the technical field of coked pure benzene extractive distillation, in particular to a raw material preheater for coked pure benzene extractive distillation. Comprising a shell, an upper partition plate and a lower partition plate are fixed in the shell, a waste heat recovery assembly is arranged between the upper partition plate and the lower partition plate, and a preheating assembly is arranged in the shell below the lower partition plate; the preheating assembly comprises a hollow upper disc and a hollow lower disc, the upper disc and the lower disc are communicated through a plurality of communicating pipes, the communicating pipes are sleeved with sleeves, a hollow confluence disc is fixed to the upper end of the lower disc, the communicating pipes penetrate through the confluence disc, the lower ends of the sleeves are communicated with the confluence disc, and the outlet end of the waste heat recovery assembly is communicated with the confluence disc. And the inlet end of the waste heat recovery assembly is communicated with the shell above the upper partition plate. According to the preheater, tower top components can be introduced between the upper partition plate and the lower partition plate, heat exchange can be conducted between the tower top components and raw materials in the heat exchange pipes, heat of the tower top components can be recycled, and therefore the production cost is reduced, and energy consumption is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of coking pure benzene extraction and distillation, in particular to a raw material preheater for coking pure benzene extraction and distillation. Background Art

[0002] Benzene is an important basic organic chemical raw material. As an intermediate for organic chemicals and fine chemicals, coking benzene is an important source of local fine chemical raw materials, and its demand is increasing year by year. Coking benzene has a complex composition and contains a variety of impurities, among which sulfide thiophene affects the deep processing of coking benzene. Although my country's coking industry has abundant thiophene resources, the processing process generally adopts the acid washing process or hydrogenation process, which makes thiophene unable to be recycled, resulting in a market shortage of this raw material.

[0003] The extraction and distillation system of coking pure benzene is composed of a raw material preheater, a carbon disulfide removal tower, an extraction and light removal tower, a main extraction tower, an extractant regeneration tower, an auxiliary extraction tower, an auxiliary extractant regeneration tower, and a thiophene refining and recovery tower connected in sequence. Coking pure benzene is the raw material. The raw material first enters the carbon disulfide removal tower through the raw material preheater. The material after carbon disulfide removal enters the extraction and light removal tower. The bottom material of the extraction and light removal tower enters the middle and upper part of the main extraction tower for extraction and refining. High-purity benzene products are obtained at the top of the main extraction tower. Thiophene and the extractant are extracted from the bottom of the main extraction tower and enter the extractant regeneration tower to recover the extractant. Thiophene and benzene are extracted from the top of the extractant regeneration tower, and the extractant at the bottom of the tower is recycled. The feed of the auxiliary extraction tower is the top discharge of the extractant regeneration tower. The benzene containing thiophene is extracted from the top of this tower. This stock of material is mixed with the raw material and enters the extraction and distillation tower for refining.

[0004] The existing raw material preheater for coking pure benzene extraction distillation generally directly uses heat transfer medium to preheat the raw material. However, a large amount of cooling water is needed to cool the carbon disulfide at the top of the carbon disulfide removal tower, so the heat in the carbon disulfide at the top of the carbon disulfide removal tower cannot be effectively utilized, and the energy consumption is high.

[0005] In the prior art, a patent document with application number CN201721825399.2 and titled "Raw Material Preheater in Propane Production Line" discloses a raw material preheater that can heat the raw material to the required temperature as needed. There are three heat exchange units in the raw material preheater. In the process of preheating the raw material, the number of heat exchange units for preheating operation can be controlled by an electric three-way valve. For example, when only two heat exchange units are needed for preheating operation, the heat exchange unit farthest from the propane entry pipe joint can be closed by the electric three-way valve. In this way, the temperature of the propane raw material discharged from the preheater can be accurately adjusted according to the actual temperature of the catalyst layer during the hydrogenation saturation reaction, so that the catalyst and the hydrogenation saturation reaction are carried out at the optimal temperature. A wavy heat exchange net is provided in the propane raw material channel between the rectangular flat tubes, and the provision of a wavy heat exchange net can improve the heat exchange efficiency of the preheater.

[0006] However, in the extraction and distillation process of coking pure benzene, there is no need to adjust the preheating temperature of coking pure benzene. At the same time, the preheater is not suitable for co-preheating the raw materials with the practical tower top material and the heat transfer medium. Utility Model Content

[0007] The technical problem to be solved by the utility model is a preheater which can use the heat of the components discharged from the top of the tower and the heat of the heat-conducting medium to preheat the raw materials. The preheater can fully utilize the heat of the components discharged from the top of the tower, reduce energy consumption and thus reduce production costs.

[0008] In order to achieve the above purpose, the technical solution provided by the utility model is:

[0009] A raw material preheater for extractive distillation of coking pure benzene comprises a shell, an upper partition and a lower partition are fixed in the shell, a waste heat recovery component is arranged between the upper partition and the lower partition, and a preheating component is arranged in the shell below the lower partition.

[0010] The preheating component includes a hollow upper plate and a lower plate. The upper plate is fixedly connected with an oil inlet pipe, and the lower plate is fixedly connected with an oil outlet pipe. The upper and lower plates are connected by multiple connecting pipes. The outer sides of the connecting pipes are sleeved with sleeves. A hollow confluence plate is fixed on the upper end of the lower plate. The connecting pipe passes through the confluence plate. The lower end of the sleeve is connected with the confluence plate. A gap is provided between the upper end of the sleeve and the lower end of the upper plate. The outlet end of the waste heat recovery component is connected with the confluence plate, and the inlet end of the waste heat recovery component is connected with the shell above the upper partition. A discharge pipe is fixedly connected to the shell below the lower partition.

[0011] Specifically, the waste heat recovery component includes a heat exchange tube, and the heat exchange tube between the upper partition and the lower partition is arranged in a serpentine shape. One end of the heat exchange tube passes through the upper partition and extends to the shell above the upper partition. The other end of the heat exchange tube passes through the lower partition and is connected to the junction plate. The shell between the upper partition and the lower partition is fixedly connected with an outlet pipe and an inlet pipe.

[0012] Specifically, a drain pipe is fixedly connected to the shell between the lower partition and the upper partition, a valve is installed on the drain pipe, and the drain pipe is close to the lower partition.

[0013] Specifically, a throttling disc is provided on the sliding sealing sleeve of the communicating pipe between the lower end of the upper plate and the upper end of the sleeve, and the throttling disc is connected to the lower partition through a telescopic assembly.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. The preheater can introduce the tower top component between the upper baffle and the lower baffle, so that the tower top component can exchange heat with the raw materials in the heat exchange tube, and the heat of the tower top component can be recycled, thereby reducing production costs and saving energy consumption.

[0016] 2. When the heat transfer medium flows in the connecting pipe, the raw material flows upward through the manifold into the gap between the sleeve and the connecting pipe, which can improve the heat exchange efficiency between the heat transfer medium and the raw material. The raw material can quickly reach the preheating temperature with high preheating efficiency.

[0017] 3. By setting a throttle disk, the throttle disk can limit the flow rate of raw materials discharged from the upper port of the sleeve. When the raw material flow rate is large, it can ensure the contact time between the raw material and the connecting pipe, and ensure that the raw material is discharged from the discharge pipe after reaching the preheating temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the preheater.

[0019] Figure 2 Schematic diagram of the preheating component.

[0020] Figure 3 A top view of the preheating assembly.

[0021] Figure 4 A cross-sectional view of the preheating assembly.

[0022] Figure 5 Schematic diagram of the connection between the bushing and the busbar.

[0023] The names of the parts in the attached drawings are:

[0024] 1 Housing

[0025] 2 Upper partition

[0026] 3 Heat exchange tubes

[0027] 4 Lower partition

[0028] 5 Inlet pipe

[0029] 6 Outlet

[0030] 7 drain pipe

[0031] 8 Upper Plate

[0032] 9 Lower plate

[0033] 10 Oil inlet pipe

[0034] 11 Oil outlet pipe

[0035] 12 Discharge pipe

[0036] 13 Busbar

[0037] 14 Connecting pipe

[0038] 15 Casing

[0039] 16 Through Holes

[0040] 17 Throttle disc

[0041] 18 Telescopic rod. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0043] Embodiment 1:

[0044] Reference Figure 1-Figure 5 As shown, the raw material preheater for extractive distillation of coking pure benzene comprises a shell 1, and a heat-insulating layer is arranged on the outer side of the shell 1. The heat-insulating layer can prevent the heat in the shell 1 from being lost.

[0045] An upper partition 2 and a lower partition 4 are fixed in the shell 1. A drain pipe 7 is fixedly connected to the shell 1 between the lower partition 4 and the upper partition 2, and a valve is installed on the drain pipe 7. The drain pipe 7 is close to the lower partition 4. An outlet pipe 6 and an inlet pipe 5 are fixedly connected to the shell 1 between the upper partition 2 and the lower partition 4.

[0046] A waste heat recovery component is arranged between the upper partition plate 2 and the lower partition plate 4. A preheating component is arranged in the shell 1 below the lower partition plate 4.

[0047] A discharge pipe 12 is fixedly connected to the shell body 1 below the lower partition plate 4 .

[0048] The preheating assembly includes a hollow upper plate 8 and a lower plate 9. The upper plate 8 is fixedly connected with an oil inlet pipe 10, and the lower plate 9 is fixedly connected with an oil outlet pipe 11. The upper plate 8 and the lower plate 9 are connected through a plurality of connecting pipes 14. The outer sides of the connecting pipes 14 are sleeved with sleeves 15. A hollow confluence plate 13 is fixed at the upper end of the lower plate 9, and the connecting pipes 14 pass through the confluence plate 13.

[0049] The lower end of the sleeve 15 is connected to the busbar 13. Specifically, the lower end of the sleeve 15 is fixed in the busbar 13, and a through hole 16 is provided on the side wall of the sleeve 15 in the busbar 13, and the through hole 16 connects the inside of the busbar 13 and the gap between the sleeve 15 and the connecting pipe 14.

[0050] A gap is provided between the upper end of the sleeve 15 and the lower end of the upper plate 8. The raw materials flowing between the sleeve 15 and the connecting pipe 14 can be discharged through the upper end of the sleeve 15 and enter the shell 1 below the lower partition 4. The raw materials in the shell 1 below the lower partition 4 can be discharged through the discharge pipe 12.

[0051] The outlet end of the waste heat recovery component is communicated with the manifold 13 , and the inlet end of the waste heat recovery component is communicated with the shell 1 above the upper partition plate 2 .

[0052] Specifically, the waste heat recovery assembly includes a heat exchange tube 3, and the heat exchange tube 3 between the upper partition 2 and the lower partition 4 is arranged in a serpentine shape. One end of the heat exchange tube 3 passes through the upper partition 2 and extends into the shell 1 above the upper partition 2. The other end of the heat exchange tube 3 passes through the lower partition 4 and is connected to the manifold 13. The raw material enters the shell 1 above the upper partition 2 from the upper end of the shell 1, and the raw material entering the shell 1 above the upper partition 2 can enter the heat exchange tube 3 and flow.

[0053] During operation, the top component enters the shell 1 between the upper partition 2 and the lower partition 4 through the inlet pipe 5, and the top component exchanges heat with the raw material in the heat exchange tube 3 in the shell 1 between the upper partition 2 and the lower partition 4. The top component condenses and remains in the shell 1 between the upper partition 2 and the lower partition 4. The valve on the drain pipe 7 can be opened to discharge and recycle the condensed top component. The tail gas between the upper partition 2 and the lower partition 4 can be discharged through the outlet pipe 6. In this embodiment, the carbon disulfide at the top of the decarbon disulfide tower can be input into the shell 1 between the upper partition 2 and the lower partition 4 through the inlet pipe 5, and the raw material in the heat exchange tube 3 is heated by the carbon disulfide at the top of the decarbon disulfide tower.

[0054] Introducing the tower top component between the upper partition 2 and the lower partition 4 can enable the tower top component to exchange heat with the raw materials in the heat exchange tube 3, and the heat of the tower top component can be recycled, thereby reducing production costs and saving energy consumption.

[0055] The heat transfer medium enters the upper plate 8 through the oil inlet pipe 10, and then flows through the connecting pipe 14 and the lower plate 9 and is discharged through the oil outlet pipe 11. After the raw materials in the heat exchange tube 3 enter the manifold 13, the raw materials go up in the gap between the sleeve 15 and the connecting pipe 14, and the raw materials flowing between the sleeve 15 and the connecting pipe 14 transfer heat with the heat transfer medium in the connecting pipe 14, thereby preheating the raw materials to the set temperature. The preheated raw materials are discharged through the discharge pipe 12.

[0056] The heat transfer medium in this embodiment is heat transfer oil.

[0057] When the heat transfer medium flows in the connecting pipe 14, the raw material flows upward into the gap between the sleeve 15 and the connecting pipe 14 through the collecting plate 13, which can improve the heat exchange efficiency between the heat transfer medium and the raw material, and the raw material can quickly reach the preheating temperature with high preheating efficiency.

[0058] Embodiment 2:

[0059] Based on Example 1, refer to Figure 1 , Figure 2 and Figure 4 As shown, a throttle disc 17 is provided on the sliding sealing sleeve of the connecting pipe 14 between the lower end of the upper plate 8 and the upper end of the sleeve 15, and the throttle disc 17 is connected to the lower partition 4 through a telescopic assembly. The telescopic assembly includes a vertically arranged telescopic rod 18. The cylinder body of the telescopic rod 18 is fixedly connected to the lower partition 4, and the telescopic end of the telescopic rod 18 is fixedly connected to the throttle disc 17.

[0060] The gap distance between the throttle disc 17 and the upper end of the sleeve 15 can be adjusted by the telescopic rod 18, thereby adjusting the flow rate of the raw material discharged from the upper end of the sleeve 15. By controlling the flow rate of the raw material discharged from the upper end of the sleeve 15, the contact time between the raw material and the connecting pipe 14 can be increased, ensuring that the raw material is discharged from the discharge pipe 12 after reaching the preheating temperature.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A raw material preheater for extractive distillation of coking pure benzene, comprising a shell (1), wherein an upper partition (2) and a lower partition (4) are fixed inside the shell (1), characterized in that: A waste heat recovery component is arranged between the upper partition (2) and the lower partition (4), and a preheating component is arranged in the shell (1) below the lower partition (4); the preheating component comprises a hollow upper plate (8) and a lower plate (9); an oil inlet pipe (10) is fixedly connected to the upper plate (8), and an oil outlet pipe (11) is fixedly connected to the lower plate (9); the upper plate (8) and the lower plate (9) are connected through a plurality of connecting pipes (14), and the outer sides of the connecting pipes (14) are all sleeved with sleeves (15); 9) A hollow confluence plate (13) is fixed at the upper end, a connecting pipe (14) passes through the confluence plate (13), the lower end of the sleeve (15) is connected to the confluence plate (13), a gap is provided between the upper end of the sleeve (15) and the lower end of the upper plate (8), the outlet end of the waste heat recovery component is connected to the confluence plate (13), the inlet end of the waste heat recovery component is connected to the shell (1) above the upper partition (2), and a discharge pipe (12) is fixedly connected to the shell (1) below the lower partition (4).

2. The raw material preheater for extractive distillation of coking pure benzene according to claim 1, characterized in that: The lower end of the sleeve (15) is fixed in the collector plate (13), and a through hole (16) is provided on the side wall of the sleeve (15) in the collector plate (13). The through hole (16) communicates the interior of the collector plate (13) and the gap between the sleeve (15) and the connecting pipe (14).

3. The raw material preheater for extractive distillation of coking pure benzene according to claim 1, characterized in that: The waste heat recovery component comprises a heat exchange tube (3), the heat exchange tube (3) between the upper partition (2) and the lower partition (4) being arranged in a serpentine shape, one end of the heat exchange tube (3) passing through the upper partition (2) and extending into the shell (1) above the upper partition (2), the other end of the heat exchange tube (3) passing through the lower partition (4) and then communicating with the collector plate (13), and an outlet tube (6) and an inlet tube (5) are fixedly connected on the shell (1) between the upper partition (2) and the lower partition (4).

4. The raw material preheater for extractive distillation of coking pure benzene according to claim 1, characterized in that: A heat-insulating layer is arranged on the outside of the shell (1).

5. The raw material preheater for extractive distillation of coking pure benzene according to claim 1, characterized in that: A liquid discharge pipe (7) is fixedly connected to the shell (1) between the lower partition (4) and the upper partition (2), a valve is installed on the liquid discharge pipe (7), and the liquid discharge pipe (7) is close to the lower partition (4).

6. The raw material preheater for extractive distillation of coking pure benzene according to claim 1, characterized in that: A throttling disc (17) is provided on the sliding sealing sleeve of the connecting pipe (14) between the lower end of the upper disc (8) and the upper end of the sleeve (15), and the throttling disc (17) is connected to the lower partition (4) through a telescopic component.

7. The raw material preheater for extractive distillation of coking pure benzene according to claim 6, characterized in that: The telescopic assembly comprises a vertically arranged telescopic rod (18), a cylinder body of the telescopic rod (18) is fixedly connected to the lower partition (4), and a telescopic end of the telescopic rod (18) is fixedly connected to the throttle disc (17).

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