Adsorption tower

Abstract

The utility model relates to the field of adsorption separation devices, in particular to an adsorption tower which is characterized in that a plurality of layers of grids are arranged in the adsorption tower; a feeding / desorption agent bus, a feeding / desorption agent distribution pipe, an extract / raffinate bus and an extract / raffinate distribution pipe are respectively and independently arranged on the grids from the first layer to the last but one layer; one end of the feeding / desorption agent distribution pipe is connected with the grid, and the other end of the feeding / desorption agent distribution pipe is connected with the feeding / desorption agent bus; one end of the extract / raffinate distribution pipe is connected with the grating, and the other end of the extract / raffinate distribution pipe is connected with the extract / raffinate bus; and an associated bypass is arranged between the extract / raffinate bus of the grids from the second layer to the last but one layer and the feed / desorption agent bus of the grid on the upper layer. According to the utility model, the feeding / desorption agent pipeline of the adsorption tower, especially the feeding / desorption agent distribution pipe, can be backwashed, and the pressure drop of the corresponding grating is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid-liquid separation, in particular to an adsorption tower. Background Art

[0002] In the ELUXYL process of the French IFP, the pressure difference of the adsorption tower grid reflects whether there are foreign objects inside the grid and the integrity of the grid. If the pressure difference of the adsorption tower grid is too high, there will be a risk of grid tearing, resulting in a large amount of adsorbent loss, which is not conducive to liquid distribution, resulting in channeling, resulting in a decrease in the uniformity of liquid mixing, and a significant decrease in the purity and yield of the PX product. Backwashing is an effective means to reduce the pressure difference of the grid, such as the adsorption tower backwashing system with utility model patent number CN207996540U: using the existing process pipeline, the liquid desorbent enters the adsorption tower through the feed / desorbent pipeline of the current layer or the lower layer, and then flows out of the adsorption tower through the extract / residual liquid pipeline of the current layer, so that the liquid entrains the solid adsorbent particles inside the grid and leaves the grid through the extract / residual liquid pipeline.

[0003] However, the layout structure of the extract / residue pipeline is different from that of the feed / desorbent pipeline. The grid is composed of a Johnson mesh, a baffle and a distribution pipe. The Johnson mesh is a metal mesh structure with two layers, which ensures that the solid adsorbent will not enter the inside of the grid under normal circumstances, while the liquid material can pass through the grid normally. Each grid is composed of three distribution pipes, including: two extract / residue distribution pipes, located on both sides; and one feed / desorbent distribution pipe, located in the middle. When the backwash is only discharged from the extract / residue pipeline, there is a short circuit of the backwash liquid, resulting in some solid adsorbent remaining in the grid and unable to be discharged, which results in the grid pressure difference not dropping significantly after backwashing, affecting the backwashing effect.

[0004] Therefore, if only the extract / residue pipeline is flushed, there will still be adsorbent remaining in the feed / desorbent pipeline, especially in the feed / desorbent distribution pipe, and the grid pressure difference decreases to a limited extent. The grid pressure difference decrease before and after a single backwash determines the frequency of backwashing. If backwashing is frequent, the device will be frequently started and stopped, causing economic losses and increasing safety risks. Therefore, it is also necessary to backwash the feed / desorbent pipeline, especially the feed / desorbent distribution pipe. Utility Model Content

[0005] In order to overcome the defect that the prior art cannot flush the feed / desorbent pipeline of the adsorption tower grid, especially the feed / desorbent distribution pipe, the utility model provides an adsorption tower, which can realize the flushing of the feed / desorbent pipeline, especially the feed / desorbent distribution pipe.

[0006] In order to achieve the above-mentioned purpose, the utility model provides an adsorption tower on the one hand, in which several layers of grids are arranged; the grids from the first layer to the second to last layer are each independently provided with a feed / desorbent bus, a feed / desorbent distribution pipe, an extract / residual liquid bus and an extract / residual liquid distribution pipe; one end of the feed / desorbent distribution pipe is connected to the grid, and the other end is connected to the feed / desorbent bus; one end of the extract / residual liquid distribution pipe is connected to the grid, and the other end is connected to the extract / residual liquid bus; an associated bypass is arranged between the extract / residual liquid bus of the second layer to the second to last layer of grids and the feed / desorbent bus of the upper layer of grids.

[0007] The main bus and the distribution pipe are separated by the wall of the adsorption tower. After entering the adsorption tower, the main bus is divided into several distribution pipes and connected to the grid.

[0008] Through the above technical scheme, for any grid layer from the first to the third-to-last grid layer, the liquid used for backwashing the feed / desorbent distribution pipe and the feed / desorbent bus can be discharged through the associated bypass via the extract / residue bus of the next grid layer, thereby realizing the backwashing of the feed / desorbent pipelines from the first to the third-to-last grid layer, especially the feed / desorbent distribution pipe, and effectively reducing the pressure drop of the corresponding grid.

[0009] Preferably, a common suction inlet pipeline is provided at the bottom of the adsorption tower, and a bottom associated bypass is provided between the bottom of the tower and the feed / desorbent bus of the penultimate grid; the bottom associated bypass is also provided with a discharge pipeline for discharging backwashing liquid.

[0010] Through the above-mentioned preferred technical scheme, the liquid in the feed / desorbent distribution pipe and the feed / desorbent bus of the penultimate grid layer can be discharged for backwashing, thereby realizing the backwashing of the feed / desorbent pipeline of the penultimate grid layer, especially the feed / desorbent distribution pipe, and effectively reducing the pressure drop between the penultimate grid layer and the bottom grid layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of an adsorption tower provided by the utility model;

[0012] Figure 2 It is a schematic diagram of backwashing of the third-to-last grid extraction liquid / residue liquid pipeline of the adsorption tower provided by the utility model;

[0013] Figure 3 It is a schematic diagram of backwashing of the penultimate grid feed / desorbent pipeline of the adsorption tower provided by the utility model;

[0014] Figure 4 It is a schematic diagram of backwashing of the penultimate grid extraction liquid / raffinate extraction liquid pipeline of the adsorption tower provided by the utility model;

[0015] Figure 5 It is a schematic diagram of backwashing of the penultimate grid feed / desorbent pipeline of the adsorption tower provided by the utility model.

[0016] Description of Reference Numerals

[0017] C601B-adsorption tower, tr-21-21st grid, tr-22-22nd grid,

[0018] tr-23-23rd grid, tr-L-bottom grid,

[0019] XV313-1st layer grid feed switch valve, XV122-21st layer grid desorbent switch valve,

[0020] XV224-23rd layer grid extraction liquid switch valve,

[0021] XV424-23rd grid residual liquid on-off valve,

[0022] SR605-Filter,

[0023] N1-discharge pipeline, CSL-common suction pipeline,

[0024] E1-Extracted liquid / residue liquid bus of the 21st grid layer,

[0025] E2 - Feed / desorbent bus for the 21st grid layer,

[0026] E3-The associated bypass between the extract / raffinate bus of the 23rd grid layer and the feed / desorbent bus of the 22nd grid layer,

[0027] RB- adsorption tower residual liquid collection pipe,

[0028] n1-first valve, n2-second valve, n3-first row of condensate guide valves, n4-second row of condensate guide valves, n5-8-shaped blind plate. DETAILED DESCRIPTION

[0029] The utility model provides an adsorption tower, wherein a plurality of grid layers are arranged in the adsorption tower; the grid layers from the first layer to the second to last layer are each independently provided with a feed / desorbent bus, a feed / desorbent distribution pipe, an extracted liquid / extracted liquid bus and an extracted liquid / extracted liquid distribution pipe, and the feed / desorbent bus, the feed / desorbent distribution pipe, the extracted liquid / extracted liquid bus and the extracted liquid / extracted liquid distribution pipe are used for conveying corresponding materials.

[0030] One end of the feed / desorbent distribution pipe is connected to the grid, and the other end is connected to the feed / desorbent bus, and one end of the extract / raffinate distribution pipe is connected to the grid, and the other end is connected to the extract / raffinate bus. The bus and the distribution pipe are separated by the wall of the adsorption tower.

[0031] Among them, the feed flows to the grid through the feed / desorbent bus and the feed / desorbent distribution pipe, and the desorbent flows to the grid through the feed / desorbent bus and the feed / desorbent distribution pipe; the extracted liquid flows out from the grid through the extracted liquid / residual liquid distribution pipe and the extracted liquid / residual liquid bus, and the residual liquid flows out from the grid through the extracted liquid / residual liquid distribution pipe and the extracted liquid / residual liquid bus.

[0032] An associated bypass is provided between the extract / raffinate bus of the second to the second-to-last grid layer and the feed / desorbent bus of the previous grid layer. The material can flow from the feed / desorbent bus of the previous grid layer into the extract / raffinate bus of the current grid layer through the associated bypass of any grid layer from the second to the second-to-last grid layer.

[0033] According to a preferred embodiment of the utility model, a common suction inlet pipeline is provided at the bottom of the adsorption tower, and a bottom associated bypass is provided between the feed / desorbent bus of the penultimate grid layer, and the common suction inlet pipeline is used to feed or extract materials from the bottom of the tower.

[0034] The tower bottom associated bypass connects the common suction inlet pipeline with the feed / desorbent bus of the penultimate grid layer, and the material can flow from the feed / desorbent bus of the penultimate grid layer into the common suction inlet pipeline through the tower bottom associated bypass.

[0035] The tower bottom associated bypass is also provided with a discharge pipeline N1 for discharging backwashing liquid.

[0036] In some embodiments of the present invention, the discharge pipeline can also be used to discharge other materials besides the backwash liquid from the tower bottom associated bypass.

[0037] In a preferred embodiment of the present invention, the backwashing liquid is passed into the filter SR605 to filter the solids therein.

[0038] Preferably, the feed / desorbent bus and the extract / raffinate bus are each independently provided with a root valve, and the root valve is used to control the flow of materials in the bus.

[0039] Preferably, the common suction inlet pipeline is also provided with a tower bottom root valve before entering the bottom of the adsorption tower.

[0040] Preferably, a valve is provided on the bypass associated with the bottom of the tower. The specific model and structure of the valve are not particularly limited and can be selected conventionally in the art as long as the function of controlling the flow of materials in the pipeline can be achieved.

[0041] Preferably, the discharge pipeline is provided with a first valve n1. The first valve n1 is used to control the flow of materials in the discharge pipeline.

[0042] The utility model has no special requirements on the number of grids of the adsorption tower. In a preferred embodiment of the utility model, the adsorption tower is provided with 10-30 layers of grids.

[0043] In a preferred embodiment of the utility model, the adsorption tower is provided with a residual liquid collection pipe RB, one end of the discharge pipeline is connected to the bypass associated with the bottom of the tower, and the other end is connected to the residual liquid collection pipe. According to the above preferred embodiment, the backwashing agent is passed into the residual liquid collection pipe for easy collection and treatment.

[0044] Preferably, a first row of condensate drain valve n3 is also provided at the low point of the bypass associated with the tower bottom, for discharging flushed solid debris.

[0045] Preferably, the discharge pipeline is provided with a second row of condensate guide valves n4 and a second valve n2. The second row of condensate guide valves n4 is used to discharge liquid when the 8-shaped blind plate n5 is disassembled. The second valve n2 is used to cut off the discharge pipeline after the second row of condensate guide valves n4 when the 8-shaped blind plate n5 is disassembled.

[0046] Preferably, an 8-shaped blind plate n5 is also provided on the discharge pipeline to prevent material from flowing into each other due to valve leakage.

[0047] In a preferred embodiment of the present invention, Figure 1 As shown, the adsorption tower C601B is provided with 24 layers of grids. E1 is the extract / raffinate bus of the 21st layer of grid tr-21, E2 is the feed / desorbent bus of the 21st layer of grid tr-21, and E3 is the associated bypass between the extract / raffinate bus of the 23rd layer of grid tr-23 and the feed / desorbent bus of the 22nd layer of grid tr-22. A discharge pipeline N1 is provided at the associated bypass at the bottom of the tower, and preferably, the other end of the discharge pipeline N1 is connected to the raffinate collecting pipe RB.

[0048] The backwashing method of the extraction liquid / residue liquid pipeline of the 22nd layer (i.e. the third layer from the end) grid is as follows: Figure 2 As shown, the feed / desorbent pipeline backwashing method is as follows Figure 3 As shown; the backwashing method of the 23rd layer (i.e. the second to last layer) grid extraction liquid / extraction residual liquid pipeline is as follows Figure 4 As shown, the feed / desorbent pipeline backwashing method is as follows Figure 5shown.

[0049] The following combination Figure 5 , specifically describe the backwashing process of the penultimate grid feed / desorbent pipeline of the adsorption tower provided by the utility model:

[0050] 1) The switch valves of the adsorption tower C601B are gradually switched to the backwash preparation bed layer, that is, the first layer grid feed switch valve XV313, the 21st layer grid desorbent switch valve XV122, the 23rd layer grid extract switch valve XV224 and the 23rd layer grid residual liquid switch valve XV424 are opened, and all the root valves are opened;

[0051] 2) Open the second valve n2 of the discharge pipeline;

[0052] 3) Open the first valve n1 of the discharge pipeline;

[0053] 4) Close the 23rd grid residual liquid on-off valve XV424;

[0054] 5) Close the 21st grid desorbent switch valve XV122;

[0055] 6) Increase the desorbent flow rate and use the desorbent as a backwashing agent. The desorbent enters the bottom of the adsorption tower C601B from the common suction inlet pipeline CSL, and passes through the bottom grid tr-L and the 23rd grid tr-23 in turn, and then passes through the 23rd grid feed / desorbent distribution pipe, the 23rd grid feed / desorbent bus to the bottom associated bypass, and finally is discharged from the adsorption tower C601B through the discharge pipeline N1.

[0056] Before adding the discharge pipeline at the bypass at the bottom of the adsorption tower, backwashing can reduce the pressure drop of the penultimate grid and the bottom grid of the adsorption tower to 48.56 kPa; after adding the discharge pipeline, backwashing can reduce the pressure drop of the penultimate grid and the bottom grid of the adsorption tower to 43.9 kPa, which is a further decrease of 4.66 kPa compared with before adding the discharge pipeline. It can be seen that adding the discharge pipeline can improve the backwashing effect of the penultimate grid and the bottom grid of the adsorption tower.

[0057] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An adsorption tower, characterized in that: Several layers of grids are arranged in the adsorption tower; The first to the second to last grid layers are each independently provided with a feed / desorbent bus, a feed / desorbent distribution pipe, an extract / raffinate bus and an extract / raffinate distribution pipe; One end of the feed / desorbent distribution pipe is connected to the grid, and the other end is connected to the feed / desorbent bus; One end of the extract / residue liquid distribution pipe is connected to the grid, and the other end is connected to the extract / residue liquid bus; An associated bypass is provided between the extract / raffinate bus of the second to the penultimate grid layer and the feed / desorbent bus of the upper grid layer.

2. The adsorption tower according to claim 1, characterized in that The adsorption tower is provided with a common suction inlet pipeline at the bottom, and a bottom-related bypass is provided between the adsorption tower and the feed / desorbent bus of the penultimate grid layer; The tower bottom associated bypass is also provided with a discharge pipeline (N1) for discharging backwashing liquid.

3. The adsorption tower according to claim 1 or 2, characterized in that: The feed / desorbent bus and the extracted liquid / raffinate bus are each independently provided with a root valve.

4. The adsorption tower according to claim 2, characterized in that: A valve is arranged on the bypass associated with the tower bottom.

5. The adsorption tower according to claim 2, characterized in that: The discharge line is provided with a first valve (n1).

6. The adsorption tower according to claim 1, characterized in that: The adsorption tower is provided with 10-30 layers of grids.

7. The adsorption tower according to claim 2, characterized in that: The adsorption tower is provided with a raffinate collecting pipe (RB), one end of the discharge pipeline is connected to the associated bypass at the bottom of the tower, and the other end is connected to the raffinate collecting pipe.

8. The adsorption tower according to claim 1, characterized in that: A first row of condensate drain valves (n3) are also provided at the lowest point of the bypass associated with the bottom of the tower to discharge the flushed solid debris.

9. The adsorption tower according to claim 2, characterized in that: The discharge pipeline is provided with a second row condensate drain valve (n4) and a second valve (n2).

10. The adsorption tower according to claim 2, characterized in that: The discharge pipeline is also provided with an 8-shaped blind plate (n5).

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