Continuous alkali washing device for dibromoethane

Abstract

The utility model relates to a continuous alkali washing device for dibromoethane, which is characterized in that the inlet end of a layering tank is connected with a horizontally arranged conveying header pipe, and liquid fed into the layering tank by the conveying header pipe is layered in the layering tank to form a light phase-middle layer-heavy phase interface; the layering tank further comprises a first output pipe which is arranged at the middle layer of the light phase-middle layer-heavy phase interface and is communicated with the layering tank along the horizontal direction; the second output pipe is arranged above the light phase-middle layer interface and is communicated with the layering tank along the horizontal direction; the third output pipe is in an inverted U shape, is arranged below the middle layer-heavy phase interface and is communicated with the layering tank, and the third output pipe is used for outputting dibromoethane and balancing the liquid level height of the light phase-middle layer-heavy phase interface in the layering tank at the same time, so that the liquid level of the light phase-middle layer-heavy phase interface is constant. The continuous layering device can be used for continuously layering, so that the layering efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical process and engineering, in particular to a dibromoethane continuous alkali washing device. Background Art

[0002] 1,2-Dibromoethane is an organic compound with the chemical formula C2H4Br2. It is a colorless, transparent liquid that is slightly soluble in water and miscible in most organic solvents. 1,2-Dibromoethane is stable and is a widely used chemical industrial raw material. It is often added to gasoline together with tetraethyl lead to convert the lead oxide produced after combustion into volatile lead bromide, which is discharged from the internal combustion engine. 1,2-Dibromoethane is also one of the important raw materials for the synthesis of diquat dibromide.

[0003] However, with the continuous expansion of the company's production scale, the demand for 1,2-dibromoethane, the precursor of the synthesis of diquat dibromide, has also increased, so it is necessary to produce a large amount of 1,2-dibromoethane. 1,2-dibromoethane is obtained by the reaction of bromine and ethylene. Because bromine and ethylene react, incomplete reaction or side reactions may occur, which will cause the generated 1,2-dibromoethane to contain a small amount of bromine. The presence of a small amount of bromine in 1,2-dibromoethane will not only reduce the purity of 1,2-dibromoethane, but also make the product contain impurities, thereby affecting its use and application. In addition, unreacted bromine may participate in side reactions, resulting in the production of undesirable by-products, thereby affecting the synthesis of diquat, so it is necessary to remove the bromine in 1,2-dibromoethane.

[0004] At present, the commonly used equipment for removing bromine from 1,2-dibromoethane is an alkali washing kettle, which is to feed the 1,2-dibromoethane to be removed of bromine into the alkali washing kettle, and then add alkali into the alkali washing kettle, and directly obtain 1,2-dibromoethane with a purity of >99% after stirring, standing and stratification, and then release the purified 1,2-dibromoethane in the alkali washing kettle, and then follow the above steps again to separate and purify the next batch of 1,2-dibromoethane. Although the bromine in 1,2-dibromoethane can be removed and 1,2-dibromoethane with a purity of >99% can be obtained, the bromine removal in the alkali washing kettle is intermittent, and the stratification efficiency is low. Utility Model Content

[0005] The purpose of the utility model is to overcome the above-mentioned problems existing in the prior art and provide a dibromoethane continuous alkali washing device, which can continuously and uninterruptedly carry out static stratification in the stratification tank for 24 hours for 1,2-dibromoethane and alkali solution containing bromine fed into the stratification tank, and continuously output 1,2-dibromoethane, alkali solution and an intermediate layer, thereby improving the stratification efficiency.

[0006] The utility model provides a dibromoethane continuous alkali washing device, comprising: a stratification tank, the inlet end of which is connected to a horizontally arranged delivery main pipe, the delivery main pipe is used to deliver alkali solution and dibromoethane bromine mixed solution, the liquid delivered into the stratification tank by the delivery main pipe will form a light phase-middle layer-heavy phase interface after stratification in the stratification tank, and the stratification tank also includes:

[0007] A first output pipe, used for outputting the middle layer, the first output pipe is arranged at the middle layer of the light phase-middle layer-heavy phase interface and is connected to the stratification tank in the horizontal direction;

[0008] A second output pipe is used to output the alkali solution. The second output pipe is arranged above the light phase-middle layer interface and is connected to the stratification tank in the horizontal direction;

[0009] The third output pipe is used to output ethylene dibromide. The third output pipe is in an inverted U shape and is arranged below the middle layer-heavy phase interface and is connected to the stratification tank. The third output pipe can also be used to balance the liquid level of the light phase-middle layer-heavy phase interface in the stratification tank to make the liquid level of the light phase-middle layer-heavy phase interface constant.

[0010] Preferably, the installation height of the inverted U-shaped third output pipe is 40%-60% of the height of the stratified tank body.

[0011] Preferably, a pipeline mixer is connected to the liquid inlet end of the delivery main pipe, and the pipeline mixer is respectively connected to a first delivery pipe and a second delivery pipe through pipelines, the first delivery pipe is used to transport 1,2-dibromoethane bromine solution, and the second delivery pipe is used to transport alkali solution.

[0012] Preferably, the pipeline mixer consists of a primary pipeline mixer and a secondary pipeline mixer, the primary pipeline mixer and the secondary pipeline mixer are connected in series through a pipeline, the inlet of the primary pipeline mixer is connected to the first delivery pipe and the second delivery pipe respectively, and the outlet of the secondary pipeline mixer is connected to the delivery main pipe.

[0013] Preferably, the output end of the second output pipe is connected to the alkali solution receiving tank; the output end of the first output pipe is connected to the middle layer receiving tank, and the output end of the third output pipe is connected to the dibromoethane receiving tank.

[0014] Preferably, the conveying main pipe is arranged in the middle of the stratified tank, and a plurality of baffles are arranged from top to bottom inside the stratified tank near the inlet of the stratified tank, and the plurality of baffles are all at an angle to the water outlet direction of the conveying main pipe, and the plurality of baffles are used to reduce material disturbance.

[0015] Preferably, the pipeline mixer, the first delivery pipe, the second delivery pipe, the delivery main pipe, the stratification tank, the second output pipe, the first output pipe and the third output pipe are all made of corrosion-resistant materials.

[0016] Preferably, the first delivery pipe, the second delivery pipe and the delivery main pipe are all provided with valves and flow meters.

[0017] Preferably, the pipeline mixer is a static mixer, and the model of the static mixer is HDSV.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. The utility model provides a dibromoethane continuous alkali washing device, which can stratify the alkali solution and dibromoethane bromine mixed solution sent into the stratification tank in the stratification tank through the difference in density, so that the stratified solution in the stratification tank forms a light phase-middle layer-heavy phase interface; and the height of the inverted U-shaped tube of the third output pipe is consistent with the height of the middle layer in the stratification tank, so the height of the inverted U-shaped tube of the third output pipe can ensure that the light phase-middle layer interface and the middle layer-heavy phase interface in the light phase-middle layer-heavy phase interface are constant, so that the middle layer, alkali solution and dibromoethane are continuously output through the first output pipe, the second output pipe and the third output pipe, thereby improving the stratification efficiency.

[0020] 2. The utility model uses a pipeline mixer to replace the stirred reactor, which has no mechanical stirring equipment, small investment and low energy consumption. In addition, the alkali solution and dibromoethane bromine mixed solution stirred in the stirred reactor need to be left in the reactor for stratification and discharge before another batch of stratification can be carried out, which is an intermittent reaction with low efficiency. In addition, if the ratio of dibromoethane and alkali solution is unbalanced during the reaction process, the whole batch of materials needs to be reworked, which will affect the time and production capacity and further increase energy consumption. The utility model only needs to adjust the delivery ratio of dibromoethane and alkali solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model is a schematic diagram of a dibromoethane continuous alkali washing device.

[0022] Description of reference numerals:

[0023] 1. The first delivery pipe, 2. The second delivery pipe, 3. The delivery main pipe, 4. The stratification tank, 5. The first output pipe, 6. The second output pipe, 7. The third output pipe, 8. The first pipeline mixer, 9. The second pipeline mixer. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1, the specific implementation of the utility model is described in detail, but it should be understood that the protection scope of the utility model is not limited by the specific implementation. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0025] The inventors have found that the currently used 1,2-dibromoethane bromine removal alkali washing kettle needs to be fully stirred and mixed with the bromine-containing 1,2-dibromoethane and the alkali solution in the alkali washing kettle through a stirring component during bromine removal. After stirring for a certain period of time, the stirring needs to be stopped and the solution in the alkali washing kettle is allowed to stand. Due to the difference in density between 1,2-dibromoethane and the alkali solution, stratification will occur during the standing process. The stratified 1,2-dibromoethane, the alkali solution and the intermediate layer between the two can be output through output pipelines connected to different liquid surface layer heights on the alkali washing kettle. This stratification process is intermittent and cannot be continuously fed, which affects the stratification efficiency. In addition, the 1,2-dibromoethane and the alkali solution in the alkali washing kettle need to be fully mixed through the stirring component, which also increases energy consumption.

[0026] In order to solve the problems existing in the above-mentioned prior art, the utility model provides a dibromoethane continuous alkali washing device.

[0027] See attached Figure 1 As shown, in the embodiment, a dibromoethane continuous alkali washing device includes: a stratification tank 4, a first output pipe 6, a second output pipe 5 and a third output pipe 7, wherein:

[0028] The inlet end of the stratification tank 4 is connected to a horizontally arranged delivery main pipe 3, which is used to deliver alkali solution and dibromoethane bromine mixed solution. The liquid delivered into the stratification tank 4 by the delivery main pipe 3 will form a light phase-middle layer-heavy phase interface after stratification in the stratification tank 4. The stratification tank 4 also includes:

[0029] The first output pipe 6 is used to output the middle layer. The first output pipe 6 is arranged at the middle layer of the light phase-middle layer-heavy phase interface and is connected to the stratification tank 4 in the horizontal direction.

[0030] The second output pipe 5 is used to output the alkali solution. The second output pipe 5 is arranged above the light phase-middle layer interface and is connected to the stratification tank 4 in the horizontal direction.

[0031] The third output pipe 7 is used to output ethylene dibromide. The third output pipe 7 is inverted U-shape and is arranged below the middle layer-heavy phase interface and is connected to the stratification tank 4. The third output pipe 7 can also be used to balance the liquid level of the light phase-middle layer-heavy phase interface in the stratification tank 4 to make the liquid level of the light phase-middle layer-heavy phase interface constant.

[0032] Working principle:

[0033] The mixed alkali solution and dibromoethane bromine mixed solution are sent into the stratification tank 4 through the conveying main pipe 3. The alkali solution here is a saturated sodium carbonate solution. Due to the density difference between the alkali solution and the dibromoethane bromine mixed solution, the alkali solution and the dibromoethane bromine mixed solution are stratified in the stratification tank 4, so that the stratified solution in the stratification tank 4 forms a light phase-intermediate layer-heavy phase interface.

[0034] The height of the inverted U-shaped tube of the third output pipe 7 is consistent with the height of the middle layer in the stratification tank, so the height of the inverted U-shaped tube of the third output pipe 7 can ensure that the light phase-middle layer interface and the middle layer-heavy phase interface are constant, thereby continuously outputting the middle layer, alkali solution and dibromoethane through the first output pipe 6, the second output pipe 5 and the third output pipe 7, thereby improving the stratification efficiency.

[0035] Specifically, the installation height of the inverted U-shaped third output pipe 7 is 40%-60% of the tank body height of the stratified tank 4. This height ratio is applicable to stratified tanks 4 of any size, and the installation height of the third output pipe 7 can clearly obtain the position of the middle layer.

[0036] Specifically, in order to further improve the stratification efficiency, it is not necessary to mix the 1,2-dibromoethane bromine solution and the alkali solution in advance, so a pipeline mixer can be connected to the liquid inlet end of the delivery main pipe 3, and the pipeline mixer is connected to the first delivery pipe 1 and the second delivery pipe 2 through pipelines, respectively, so that the 1,2-dibromoethane bromine solution and the alkali solution can be fully mixed in the delivery main pipe 3 through the pipeline mixer.

[0037] Specifically, in order to increase the mixing intensity, a plurality of pipeline mixers are connected in series on the delivery main pipe 3, so the pipeline mixer consists of a primary pipeline mixer 8 and a secondary pipeline mixer 9. The primary pipeline mixer 8 and the secondary pipeline mixer 9 are connected in series through a pipeline, and the inlet of the primary pipeline mixer 8 is respectively connected to the first delivery pipe 1 and the second delivery pipe 2, and the outlet of the secondary pipeline mixer 9 is connected to the delivery main pipe 3, so that the solutions flowing through the primary pipeline mixer 8 and the secondary pipeline mixer 9 can be fully mixed.

[0038] Specifically, in order to facilitate the recovery of alkali solution, intermediate layer solution and dibromoethane, the output end of the second output pipe 5 is connected to the alkali solution receiving tank; the output end of the first output pipe 6 is connected to the intermediate layer receiving tank, and the output end of the third output pipe 7 is connected to the dibromoethane receiving tank.

[0039] Specifically, the conveying main pipe 3 is arranged in the middle part of the stratification tank 4, and a plurality of baffles are arranged from top to bottom inside the stratification tank 4 near the inlet of the stratification tank 4, and the plurality of baffles are all at an angle to the water outlet direction of the conveying main pipe 3. The plurality of baffles are used to reduce material disturbance and can improve the stratification efficiency of the stratification tank 4.

[0040] Specifically, the pipeline mixer, the first delivery pipe 1, the second delivery pipe 2, the delivery main pipe 3, the stratification tank 4, the second output pipe 5, the first output pipe 6 and the third output pipe 7 are all made of corrosion-resistant materials to increase the service life of the equipment. The corrosion-resistant material can be 304L stainless steel.

[0041] Specifically, valves and flow meters are provided on the first delivery pipe 1 , the second delivery pipe 2 and the delivery main pipe 3 for reasonably regulating the delivery volume of the liquid flowing through the first delivery pipe 1 and the second delivery pipe 2 .

[0042] Specifically, the pipeline mixer is a static mixer, model HDSV.

[0043] The utility model provides a dibromoethane continuous alkali washing device, which can stratify the alkali solution and the dibromoethane bromine mixed solution fed into the stratification tank 3 in the stratification tank 3 through the difference in density, so that the stratified solution in the stratification tank 3 forms a light phase-middle layer-heavy phase interface; and the height of the inverted U-shaped tube of the third output pipe 7 is consistent with the height of the middle layer in the stratification tank 3, so the height of the inverted U-shaped tube of the third output pipe 7 can ensure that the light phase-middle layer interface and the middle layer-heavy phase interface in the light phase-middle layer-heavy phase interface are constant, so that the middle layer, alkali solution and dibromoethane are continuously output through the first output pipe 6, the second output pipe 5 and the third output pipe 7, thereby improving the stratification efficiency.

[0044] The utility model replaces the stirred reactor with a pipeline mixer, has no mechanical stirring equipment, has low investment and low energy consumption. In addition, the alkali solution and dibromoethane bromine mixed solution stirred in the stirred reactor need to be left to stand in the reactor for stratification and discharge before another batch of stratification can be carried out, which is an intermittent reaction with low efficiency. In addition, if the ratio of dibromoethane and alkali solution is unbalanced during the reaction, the whole batch of materials needs to be reworked, which will affect the time and production capacity and further increase energy consumption. The utility model only needs to adjust the delivery ratio of dibromoethane and alkali solution.

[0045] Although the 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 dibromoethane continuous alkali washing device, characterized in that: include: A stratification tank (4), wherein a horizontally arranged delivery main pipe (3) is connected to the inlet end of the stratification tank (4), wherein the delivery main pipe (3) is used to deliver an alkali solution and a dibromoethane bromine mixed solution, and the liquid delivered into the stratification tank (4) by the delivery main pipe (3) forms a light phase-middle layer-heavy phase interface after stratification in the stratification tank (4), and the stratification tank (4) further comprises: A first output pipe (6) is used to output the middle layer. The first output pipe (6) is arranged at the middle layer of the light phase-middle layer-heavy phase interface and is connected to the stratification tank (4) in a horizontal direction. A second output pipe (5) is used to output the alkali solution. The second output pipe (5) is arranged above the light phase-middle layer interface and is connected to the stratification tank (4) in the horizontal direction. The third output pipe (7) is used to output ethylene dibromide. The third output pipe (7) is in an inverted U shape and is arranged below the interface between the middle layer and the heavy phase and is connected to the stratification tank (4). The third output pipe (7) is used to output ethylene dibromide. At the same time, the third output pipe (7) can also be used to balance the liquid level of the interface between the light phase, the middle layer and the heavy phase in the stratification tank (4) so ​​that the liquid level of the light phase, the middle layer and the heavy phase interface is constant.

2. A dibromoethane continuous alkali washing device according to claim 1, characterized in that: The installation height of the inverted U-shaped third output pipe (7) is 40%-60% of the height of the tank body of the stratified tank (4).

3. A dibromoethane continuous alkali washing device according to claim 1, characterized in that: A pipeline mixer is connected to the liquid inlet end of the main delivery pipe (3), and the pipeline mixer is respectively connected to a first delivery pipe (1) and a second delivery pipe (2) through pipelines, wherein the first delivery pipe (1) is used to deliver 1,2-dibromoethane bromine solution, and the second delivery pipe (2) is used to deliver alkali solution.

4. A dibromoethane continuous alkali washing device according to claim 3, characterized in that: The pipeline mixer is composed of a primary pipeline mixer (8) and a secondary pipeline mixer (9), wherein the primary pipeline mixer (8) and the secondary pipeline mixer (9) are connected in series via a pipeline, wherein the inlet of the primary pipeline mixer (8) is respectively connected to the first delivery pipe (1) and the second delivery pipe (2), and the outlet of the secondary pipeline mixer (9) is connected to the delivery main pipe (3).

5. The dibromoethane continuous alkali washing device according to claim 1, characterized in that: The output end of the second output pipe (5) is connected to the alkali solution receiving tank; the output end of the first output pipe (6) is connected to the intermediate layer receiving tank, and the output end of the third output pipe (7) is connected to the dibromoethane receiving tank.

6. The dibromoethane continuous alkali washing device according to claim 1, characterized in that: The main conveying pipe (3) is arranged in the middle of the stratified tank (4), and a plurality of baffles are arranged from top to bottom inside the stratified tank (4) near the inlet of the stratified tank (4), and the plurality of baffles are all at an angle to the water outlet direction of the main conveying pipe (3), and the plurality of baffles are used to reduce material disturbance.

7. A dibromoethane continuous alkali washing device according to claim 4, characterized in that: The pipeline mixer, the first delivery pipe (1), the second delivery pipe (2), the delivery main pipe (3), the stratification tank (4), the second output pipe (5), the first output pipe (6) and the third output pipe (7) are all made of corrosion-resistant materials.

8. The dibromoethane continuous alkali washing device according to claim 3, characterized in that: The first delivery pipe (1), the second delivery pipe (2) and the delivery main pipe (3) are all provided with valves and flow meters.

9. The dibromoethane continuous alkali washing device according to claim 3, characterized in that: The pipeline mixer is a static mixer, and the model of the static mixer is HDSV.

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