A device for removing butadiene polymerization inhibitor

Abstract

The invention discloses a butadiene inhibitor removal device, comprising an alkali washing tank, a water washing tank and a separation tank, wherein the alkali washing tank is provided with a feed pipe, a drain pipe and an alkali liquid pipe, the alkali washing tank is provided with a first inner coil, one end of the feed pipe extending into the alkali washing tank is connected with the first inner coil; the top of the alkali washing tank is connected with the water washing tank through a first connecting pipe, the water washing tank is provided with a second inner coil, one end of the first connecting pipe extending into the water washing tank is connected with the second inner coil, a plurality of discharge holes are provided on the first inner coil and the second inner coil, the top of the water washing tank is connected with a water inlet pipe; the top of the water washing tank is connected with the separation tank through a second connecting pipe, and one end of the second connecting pipe extends into the separation tank, and the water washing tank is provided with a discharge pipe; the discharge port at the bottom of the water washing tank and the discharge port at the bottom of the separation tank are respectively connected with the top of the alkali washing tank; the alkali washing tank, the water washing tank and the separation tank are respectively connected with a venting pipe. The invention improves the removal effect of the inhibitor in butadiene.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, in particular to a butadiene polymerization inhibitor removal device. Background Art

[0002] Butadiene is a colorless gas at room temperature and pressure. It is insoluble in water but easily soluble in non-polar solvents. It is often used as the main raw material for synthetic rubber, synthetic resin, etc. Since butadiene is easy to self-polymerize or produce peroxides under oxygen conditions, butadiene manufacturers usually add tert-butylcatechol as an inhibitor during the storage of butadiene to reduce the production of self-polymers, avoid affecting product quality, and create safety hazards. During the use of butadiene, the inhibitor has a great influence on the polymerization reaction rate. In most existing production facilities, a set of inhibitor removal equipment is required to remove the inhibitor in butadiene.

[0003] The commonly used polymerization inhibitor in butadiene is p-tert-butylcatechol. According to the different seasonal temperatures, the amount added by butadiene manufacturers is controlled at 40-150ppm. Before normal use, sodium hydroxide is used to react with the polymerization inhibitor to generate salt, which is then dissolved in water and then used after stratification. In actual production and use, butadiene is usually passed into a horizontal alkali washing tank with sodium hydroxide aqueous solution, so that the polymerization inhibitor reacts with sodium hydroxide to produce sodium salt and dissolves in water. Since butadiene is insoluble in water and lighter than water, it is in the upper layer of water after stratification, and gradually pushes into the separation tank. After standing for a period of time, a small amount will be stratified to the bottom of the tank, and the upper butadiene is ready for use. At present, in the process of removing inhibitors from butadiene, the following problems mainly exist: First, the inhibitors in butadiene are not completely removed. Normal use generally requires less than 6ppm, but it often exceeds this value, even reaching more than 15ppm; second, when butadiene is statically layered in the separation tank, it is difficult to separate it cleanly, and a small amount of alkali solution is often brought into the polymerization kettle, which has a great impact on the polymerization reaction; third, in order to better remove the inhibitors in butadiene, butadiene and alkali solution are used to enter the static mixer at a certain time and then enter the alkali washing tank to fully mix and remove butadiene, but due to different inlet pressures, the flow ratio is inconvenient to adjust, and trace impurities are easy to block the static mixer; fourth, the temperature is different, and the alkali washing effect at different times is also different. Therefore, in actual production, how to improve the removal effect of inhibitors in butadiene is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a device for removing polymerization inhibitor of butadiene, so as to solve the problems existing in the above-mentioned prior art and improve the effect of removing polymerization inhibitor from butadiene.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The invention provides a butadiene polymerization inhibitor removal device, comprising an alkali washing tank, a water washing tank and a separation tank, wherein the alkali washing tank is provided with a feed pipe, a drain pipe and an alkali liquid pipe, the alkali washing tank is provided with a first inner coil, one end of the feed pipe extending into the alkali washing tank is connected with the first inner coil; the top of the alkali washing tank is connected with the water washing tank through a first connecting pipe, the water washing tank is provided with a second inner coil, one end of the first connecting pipe extending into the water washing tank is connected with the second inner coil, a plurality of discharge holes are provided on the first inner coil and the second inner coil, the top of the water washing tank is connected with a water inlet pipe; the top of the water washing tank is connected with the separation tank through a second connecting pipe, and one end of the second connecting pipe extends into the separation tank, the water washing tank is provided with a discharge pipe; the discharge port at the bottom of the water washing tank and the discharge port at the bottom of the separation tank are respectively connected with the top of the alkali washing tank; the alkali washing tank, the water washing tank and the separation tank are respectively connected with a venting pipe.

[0007] Preferably, there is a gap of 30cm to 40cm between the first inner coil and the bottom end of the alkali washing tank, there is a gap of 30cm to 40cm between the second inner coil and the bottom end of the water washing tank, and the discharge holes on the first inner coil and the second inner coil are both facing downward.

[0008] Preferably, a first feed valve is provided on the feed pipe; a first discharge valve and a second feed valve are provided on the first connecting pipe, the first discharge valve is close to the alkali washing tank, and the second feed valve is close to the water washing tank; a water inlet valve is provided on the water inlet pipe; a second discharge valve and a third feed valve are provided on the second connecting pipe, the second discharge valve is close to the water washing tank, and the third feed valve is close to the separation tank; and a third discharge valve is provided on the discharge pipe.

[0009] Preferably, a first vent valve is provided on the connecting pipe between the alkali washing tank and the vent pipe, a second vent valve is provided on the connecting pipe between the water washing tank and the vent pipe, and a third vent valve is provided on the connecting pipe between the separation tank and the vent pipe.

[0010] Preferably, the first inner coil is fixedly connected to the inner wall of the alkali washing tank, and the second inner coil is fixedly connected to the inner wall of the water washing tank.

[0011] Preferably, liquid level gauges are provided on both the alkali washing tank and the separation tank.

[0012] Preferably, the alkali washing tank, the water washing tank and the separation tank are all provided with a pressure gauge and a temperature gauge.

[0013] Preferably, manholes are respectively provided at the bottom of the alkali washing tank, the bottom of the water washing tank and the bottom of the separation tank.

[0014] Compared with the prior art, the present invention has achieved the following technical effects:

[0015] The butadiene polymerization inhibitor removal device of the present invention improves the removal effect of polymerization inhibitors in butadiene. In the butadiene polymerization inhibitor removal device of the present invention, the alkali washing tank is set as a vertical tank, which can increase the liquid level of the alkali solution, increase the contact time between the alkali solution and butadiene, and make the polymerization inhibitor in butadiene and the alkali solution react more fully; butadiene is introduced into the alkali washing tank through the first inner coil, and the inner coil is porous, which can increase the full contact with the alkali solution and improve the removal effect of the polymerization inhibitor; a jacket is added to the outside of the alkali washing tank, and cold water and hot water are introduced to control the internal temperature when it is high in summer and low in winter, so as to ensure that the internal alkali washing effect is stable, and further At high temperatures, cooling water is used to ensure safety. At low temperatures, due to the reduced solubility of the internal alkali solution and sodium phenolate, crystal precipitation is avoided to prevent direct blockage of the alkali solution circulation system. A water washing tank is added between the alkali washing tank and the separation tank, so that the butadiene quickly separated from the alkali washing tank can be further washed with water to remove a small amount of sodium hydroxide solution and sodium tert-butylcatechol in the butadiene. At the same time, a second inner coil is arranged in the water washing tank to achieve a better washing effect. After further separation, the water is introduced into the separation tank and allowed to stand for stratification before use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a butadiene polymerization inhibitor removal device of the present invention;

[0018] Figure 2 It is a schematic structural diagram of the first inner coil in the butadiene polymerization inhibitor removal device of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the second inner coil in the butadiene polymerization inhibitor removal device of the present invention;

[0020] Wherein: 100, butadiene inhibitor removal device; 1, alkali washing tank; 101, first liquid level gauge; 102, drain valve; 103, alkali liquid valve; 2, water washing tank; 3, separation tank; 301, second liquid level gauge; 4, separation liquid pipe; 5, vent pipe; 6, water inlet pipe; 7, feed pipe; 8, first connecting pipe; 9, second connecting pipe; 10, discharge pipe; 11, liquid discharge port; 12, first feed valve; 13, first vent valve; 14, first discharge valve; 15, separation liquid valve; 16, second feed valve; 17, second vent valve; 18, water inlet valve; 19, second discharge valve; 20, third feed valve; 21, third vent valve; 22, third discharge valve; 23, manhole; 24, first inner coil; 2401, first discharge hole; 25, second inner coil; 2501, second discharge hole. DETAILED DESCRIPTION

[0021] 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, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The purpose of the present invention is to provide a device for removing polymerization inhibitor of butadiene, so as to solve the problems existing in the above-mentioned prior art and improve the effect of removing polymerization inhibitor from butadiene.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 3 As shown: This embodiment provides a butadiene polymerization inhibitor removal device 100, including an alkali washing tank 1, a water washing tank 2 and a separation tank 3.

[0025] Among them, the alkali cleaning tank 1 is provided with a feed pipe 7, a drain pipe, an alkali liquid pipe and a first liquid level gauge 101, a first inner coil 24 is provided in the alkali cleaning tank 1, and there is a 30cm to 40cm interval between the first inner coil 24 and the bottom end of the alkali cleaning tank 1, the first inner coil 24 is fixedly connected to the inner wall of the alkali cleaning tank 1, and a plurality of first discharge holes 2401 facing downward are evenly provided on the first inner coil 24, one end of the feed pipe 7 extending into the alkali cleaning tank 1 is connected to the first inner coil 24, and the top of the alkali cleaning tank 1 is connected to the water washing tank 2 through the first connecting pipe 8. A first feed valve 12 is provided on the feed pipe 7; a first discharge valve 14 and a second feed valve 16 are provided on the first connecting pipe 8, the first discharge valve 14 is close to the alkali cleaning tank 1, and the second feed valve 16 is close to the water washing tank 2. The alkali cleaning tank 1 is a vertical tank, and a jacket is provided on the outside of the alkali cleaning tank 1 , and hot water and / or cold water can be passed into the jacket to control the internal temperature of the alkali cleaning tank 1 to ensure a stable alkali cleaning effect inside the alkali cleaning tank 1 .

[0026] A second inner coil 25 is arranged in the water washing tank 2, and there is a gap of 30cm to 40cm between the second inner coil 25 and the bottom end of the water washing tank 2. The second inner coil 25 is fixedly connected to the inner wall of the water washing tank 2, and a plurality of second discharge holes 2501 facing downward are evenly arranged on the second inner coil 25. The discharge holes on the first inner coil 24 and the discharge holes on the second inner coil 25 are both facing downward; one end of the first connecting pipe 8 extending into the water washing tank 2 is connected with the second inner coil 25, and the top of the water washing tank 2 is connected with the water inlet pipe 6; the top of the water washing tank 2 is connected with the separation tank 3 through the second connecting pipe 9, and the water inlet pipe 6 is provided with a water inlet valve 18; the second connecting pipe 9 is provided with a second discharge valve 19 and a third feed valve 20, the second discharge valve 19 is close to the water washing tank 2, and the third feed valve 20 is close to the separation tank 3.

[0027] One end of the second connecting pipe 9 extends into the separation tank 3, and a discharge pipe 10 is provided on the water washing tank 2; the discharge port 11 at the bottom end of the water washing tank 2 and the discharge port 11 at the bottom end of the separation tank 3 are respectively connected to the separation liquid pipe 4, one end of the separation liquid pipe 4 is connected to the top end of the alkali washing tank 1, and a separation liquid valve 15 is provided on the separation liquid pipe 4; a third discharge valve 22 is provided on the discharge pipe 10; and a second liquid level meter 301 is provided on each of the separation tanks 3.

[0028] The alkali washing tank 1, the water washing tank 2 and the separation tank 3 are respectively connected to the vent pipe 5. A first vent valve 13 is provided on the connecting pipe between the alkali washing tank 1 and the vent pipe 5, a second vent valve 17 is provided on the connecting pipe between the water washing tank 2 and the vent pipe 5, and a third vent valve 21 is provided on the connecting pipe between the separation tank 3 and the vent pipe 5.

[0029] Pressure gauges and temperature gauges are provided on the alkali washing tank 1, the water washing tank 2 and the separation tank 3. Manholes 23 are provided at the bottom of the alkali washing tank 1, the bottom of the water washing tank 2 and the bottom of the separation tank 3, respectively.

[0030] The specific method of using the butadiene polymerization inhibitor removal device 100 of this embodiment is as follows:

[0031] (1) Clean the alkali cleaning tank 1, the water washing tank 2 and the separation tank 3, and replace the oxygen content in the tanks with nitrogen until the oxygen content is less than 0.2%; (2) Add alkali solution (concentration 10-15%) to the alkali cleaning tank 1 through the alkali solution valve 103 on the alkali solution pipe, the volume of which is 50-60% of the volume of the tank body of the alkali cleaning tank 1, then close the alkali solution valve 103, open the water inlet valve 18, add deionized water to the water washing tank 2, the volume of the deionized water added is 50-60% of the volume of the tank body of the water washing tank 2, and then close the water inlet valve 18; (3) Open the jacket inlet and outlet valves of the alkali cleaning tank 1, and pass cold water and / or hot water to control the alkali solution temperature at 15-20°C; (4) Open the first feed valve 12, and continuously pump butadiene into the alkali cleaning tank through the butadiene pump, and disperse it into the alkali cleaning tank 1 through the first inner coil 24. After flowing out of the first inner coil 24 through the first discharge hole 2401, it can fully contact with the alkali solution, gradually move upward, and be layered on the upper part of the alkali solution; (5) Open the first discharge valve 14 and the second feed valve 16, press the butadiene after alkali washing into the water washing tank 2, and disperse the butadiene into the water in the water washing tank 2 through the second inner coil 25 at the bottom. After the butadiene fully contacts with the water, it gradually moves to the upper part and layers with the water; (6) Open the second discharge valve 19 and the third feed valve 20, press the butadiene after water washing into the separation tank 3. After reaching 80% of the volume of the separation tank 3, close the first feed valve 12 and the butadiene pump, stop alkali washing, let it stand for 2-3 hours, and take samples from the discharge pipe 10 to test butadiene. The content of butadiene inhibitor is 5ppm, and there is no red alkali solution impurity in butadiene, which meets the quality requirements. In order to better control the quality and achieve the butadiene alkali washing effect, when the sodium hydroxide concentration in the alkali solution drops by 2% or the solid content of the alkali solution increases by 4-5%, the alkali solution must be replaced in time, the drain valve 102 on the drain pipe is opened, the waste alkali solution is discharged, and then new alkali solution is added through the alkali solution pipe. It can be used and all indicators meet the requirements.

[0032] The main function of the separation tank 3 is that after butadiene is left to stand, due to the insolubility of butadiene in water and different densities, butadiene and water are automatically separated, and a small amount of water in butadiene is separated to the bottom of the tank. This water is the water that butadiene brings with it after being separated from the water washing tank 2 and pressed into the separation tank 3. The gas in the alkali washing tank 1, the water washing tank 2 and the separation tank 3 can be conveniently discharged through the vent pipe 5 in conjunction with the first vent valve 13, the second vent valve 17 and the third vent valve 21. The liquid separated in the water washing tank 2 and the separation tank 3 can be discharged into the alkali washing tank 1 for utilization through the drain port 11 at the bottom of the water washing tank 2 and the drain port 11 at the bottom of the separation tank 3.

[0033] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top", "bottom", "inner", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A device for removing butadiene polymerization inhibitor, characterized in that: The invention comprises an alkali washing tank, a water washing tank and a separation tank, wherein the alkali washing tank is provided with a feed pipe, a drain pipe and an alkali liquid pipe, the alkali washing tank is provided with a first inner coil, one end of the feed pipe extending into the alkali washing tank is communicated with the first inner coil; the top of the alkali washing tank is communicated with the water washing tank through a first connecting pipe, a second inner coil is provided in the water washing tank, one end of the first connecting pipe extending into the water washing tank is communicated with the second inner coil, a plurality of discharge holes are provided on the first inner coil and the second inner coil, the top of the water washing tank is connected with a water inlet pipe; the top of the water washing tank is communicated with the separation tank through a second connecting pipe, and one end of the second connecting pipe extends into the separation tank, and the water washing tank is provided with a discharge pipe; the discharge port at the bottom end of the water washing tank and the discharge port at the bottom end of the separation tank are respectively communicated with the top end of the alkali washing tank; the alkali washing tank, the water washing tank and the separation tank are respectively communicated with a vent pipe; The alkali cleaning tank is provided with a jacket on its exterior, and hot water and / or cold water is introduced into the jacket to control the internal temperature of the alkali cleaning tank.

2. The butadiene polymerization inhibitor removal device according to claim 1, characterized in that: There is a gap of 30cm to 40cm between the first inner coil and the bottom end of the alkali washing tank, and there is a gap of 30cm to 40cm between the second inner coil and the bottom end of the water washing tank. The discharge holes on the first inner coil and the second inner coil are both facing downward.

3. The butadiene polymerization inhibitor removal device according to claim 1, characterized in that: A first feed valve is provided on the feed pipe; a first discharge valve and a second feed valve are provided on the first connecting pipe, the first discharge valve is close to the alkali washing tank, and the second feed valve is close to the water washing tank; a water inlet valve is provided on the water inlet pipe; a second discharge valve and a third feed valve are provided on the second connecting pipe, the second discharge valve is close to the water washing tank, and the third feed valve is close to the separation tank; a third discharge valve is provided on the discharge pipe.

4. The butadiene polymerization inhibitor removal device according to claim 1, characterized in that: A first vent valve is provided on the connecting pipe between the alkali washing tank and the vent pipe, a second vent valve is provided on the connecting pipe between the water washing tank and the vent pipe, and a third vent valve is provided on the connecting pipe between the separation tank and the vent pipe.

5. The device for removing butadiene polymerization inhibitor according to claim 1, characterized in that: The first inner coil is fixedly connected to the inner wall of the alkali washing tank, and the second inner coil is fixedly connected to the inner wall of the water washing tank.

6. The device for removing butadiene polymerization inhibitor according to claim 1, characterized in that: Liquid level gauges are provided on the alkali washing tank and the separation tank.

7. The device for removing butadiene polymerization inhibitor according to claim 1, characterized in that: The alkali washing tank, the water washing tank and the separation tank are all provided with a pressure gauge and a temperature gauge.

8. The device for removing butadiene polymerization inhibitor according to claim 1, characterized in that: Manholes are respectively provided at the bottom of the alkali washing tank, the bottom of the water washing tank and the bottom of the separation tank.

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