A high-efficiency production device for sodium pyrithione

Abstract

The utility model discloses a kind of pyrithione sodium high-efficiency production devices, belong to pyrithione sodium production technical field, including refining kettle, acid supply device, washing device, alkali supply device and gas treatment device are connected to refining kettle, filter screen is equipped in refining kettle, filter screen is horizontally arranged, and suction tube is fixedly connected on the upper surface of filter screen, and the end of suction tube away from filter screen projects out of refining kettle;Filter screen can move at first height and second height, when filter screen is at first height, into acid liquor into refining kettle, filter screen is higher than liquid level in refining kettle, 2-mercapto pyridine-N-oxide is precipitated, impurities are left in solution;When filter screen is at second height, suction tube is located in liquid in refining kettle and extracts solution.The utility model completes purification process in refining kettle, reduces the loss caused by material transfer, reduces production cost.

Description

Technical Field

[0001] This utility model relates to the field of sodium pyridinethione production technology, specifically to a high-efficiency sodium pyridinethione production device. Background Technology

[0002] Sodium pyrithione (SPT), chemically known as 2-mercaptopyridine-N-oxide sodium salt, is a white or off-white powder in its pure form. Currently, industrially, it is mainly synthesized using 2-chloropyridine or pyridine as raw materials. Using 2-chloropyridine as a raw material, in the presence of a catalyst and with hydrogen peroxide as an oxidant, a solution of 2-chloropyridine-N-oxide is synthesized. This solution is then reacted with sodium hydroxide and sodium hydrosulfide solutions to obtain crude sodium pyrithione. In existing technologies, sodium pyrithione is converted to 2-mercaptopyridine-N-oxide through acid precipitation. The 2-mercaptopyridine-N-oxide precipitates in an aqueous solution. The resulting solid 2-mercaptopyridine-N-oxide is separated and then dissolved in an aqueous sodium hydroxide solution to complete the purification of sodium pyrithione.

[0003] However, in existing technologies, the purification process of sodium pyrithione is typically carried out in multiple units. The transfer of sodium pyrithione between these units results in losses, and the multiple units increase production costs. Furthermore, 2-mercaptopyridine-N-oxide is easily and slowly oxidized in air, which is detrimental to the production of sodium pyrithione.

[0004] In view of the problems existing in the prior art, this utility model combines years of design and use experience in related fields to design and manufacture a high-efficiency production device for sodium pyrithione to overcome the above defects. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model provides a high-efficiency production device for sodium pyridinethione, which completes the purification process of sodium pyridinethione in one device, reducing losses caused during material transfer and the degree of oxidation of 2-mercaptopyridine-N-oxide, thereby reducing production costs.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a high-efficiency production device for sodium pyrithione, comprising a refining kettle, wherein the refining kettle is connected to an acid supply device, a washing device, an alkali supply device and a gas treatment device, wherein a filter screen is provided inside the refining kettle, the filter screen is horizontally arranged and the filter screen can move between a first height and a second height;

[0007] A liquid extraction tube is fixedly connected to the upper surface of the filter screen, and the end of the liquid extraction tube away from the filter screen extends out of the refining kettle;

[0008] When the filter screen is at its first height, it is above the liquid level in the refining vessel; when the filter screen is at its second height, the lower end of the suction pipe is inside the liquid in the refining vessel.

[0009] Preferably, the lower surface of the filter screen is provided with an annular sleeve, the annular sleeve is coaxially arranged with the rotating shaft, a gap is left between the annular sleeve and the rotating shaft, and the inner surface of the annular sleeve is circumferentially distributed with first bristles, which are in contact with the rotating shaft.

[0010] Preferably, the liquid extraction tube has an elastic tube, which is located inside the refining vessel and is vertically arranged.

[0011] Preferably, the refining vessel is equipped with an electric telescopic rod for driving the filter screen to move.

[0012] Preferably, the inner wall of the refining vessel is provided with a plurality of longitudinal slide rails, and the top and bottom ends of the longitudinal slide rails are provided with limiting blocks, and the outer edge of the filter screen is provided with an inner concave wall that matches the longitudinal slide rails.

[0013] Preferably, the lower surface of the concave wall is provided with a semi-annular sleeve, and the inner surface of the semi-annular sleeve is provided with a second brush bristle, which contacts the longitudinal slide rail.

[0014] Preferably, a rotating shaft is vertically installed inside the refining vessel. The top end of the rotating shaft passes through the filter screen and the top end of the refining vessel in sequence and is connected to a motor. A stirring rod is installed at the lower end of the rotating shaft. The stirring rod and the filter screen do not interfere with each other.

[0015] Preferably, the end of the extraction pipe located outside the refining vessel is connected to a waste liquid tank.

[0016] Preferably, along the liquid flow direction, the liquid extraction pipe is sequentially equipped with a liquid extraction pump and a first three-way valve;

[0017] The first three-way valve is connected to the washing device through the return pipe.

[0018] Preferably, the refining vessel is provided with a nitrogen inlet.

[0019] The advantages of this utility model are:

[0020] 1. This utility model features a filter screen that moves at a first height and a second height. At the first height, the filter screen is higher than the liquid level in the refining vessel. Acid is added through the acid supply device, and the crude pyridinethione is converted into 2-mercaptopyridine-N-oxide and precipitated, while impurities remain in the solution. The 2-mercaptopyridine-N-oxide is located below the filter screen, reducing the load on the filter screen. At the second height, the liquid extraction pipe is located inside the liquid in the refining vessel. The liquid extraction pipe extracts the solution, which is then washed by a washing device and alkali is introduced through an alkali supply device to obtain purified sodium pyridinethione. The purification process of sodium pyridinethione is completed in the refining vessel, thereby reducing losses caused by material transfer and lowering production costs.

[0021] 2. This utility model has an annular sleeve and a first brush on the lower surface of the filter screen. When the filter screen moves, the first brush can scrape off the solid 2-mercaptopyridine-N-oxide on the rotating shaft. A semi-annular sleeve and a second brush are provided on the lower surface of the inner concave wall of the filter screen. When the filter screen moves, the second brush can scrape off the solid 2-mercaptopyridine-N-oxide on the longitudinal slide rail, thus avoiding affecting the movement of the filter screen.

[0022] 3. In this invention, nitrogen gas is introduced into the refining vessel through a nitrogen inlet, and air is discharged to avoid oxidation of 2-mercaptopyridine-N-oxide upon contact with air. Volatile hydrogen chloride gas is released during the air discharge, so the air enters a gas treatment device for processing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a high-efficiency pyridinethione sodium production device.

[0024] Figure 2 This is a cross-sectional view of a high-efficiency sodium pyrithione production unit.

[0025] Figure 3 This is a bottom view of a filter screen in a high-efficiency sodium pyrithione production device.

[0026] In the diagram: 1-Refining kettle, 2-First liquid inlet, 3-Second liquid inlet, 4-Gas outlet, 5-Alkali outlet, 6-Liquid outlet, 7-Filter screen, 8-Liquid extraction pipe, 9-Liquid extraction pump, 10-Waste liquid tank, 11-Electric telescopic rod, 12-Elastic tube, 13-Motor, 14-Rotating shaft, 15-Stirring rod, 16-Annular sleeve, 17-First brush bristles, 18-Longitudinal slide rail, 19-Inner concave wall, 20-Second brush bristles, 21-Semi-annular sleeve, 22-First three-way valve, 23-Return pipe, 24-Washing tank, 25-Acid supply tank, 26-Acid pipeline, 27-Second three-way valve, 28-Window, 29-Limiting block, 30-Nitrogen inlet, 31-Water pipeline, 32-Alkali supply tank, 33-Alkali pipeline, 34-Alkali valve. Detailed Implementation

[0027] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0028] like Figures 1-3As shown, a high-efficiency production apparatus for sodium pyridinethione includes a refining vessel 1. The top of the refining vessel 1 has a first inlet 2 for introducing a solution containing crude sodium pyridinethione into the refining vessel 1. The refining vessel 1 is connected to an acid supply device, a washing device, an alkali supply device, and a gas treatment device. The bottom of the refining vessel 1 has a liquid outlet 6. A filter screen 7 is installed inside the refining vessel 1, located below the first inlet 2, and is horizontally positioned. The solution containing crude sodium pyridinethione may contain a small amount of unseparated catalyst impurities. The filter screen 7 filters out these catalyst impurities, leaving solid impurities on the filter screen 7. The filter screen 7 can move between a first height and a second height. The refining vessel 1 is equipped with an electric telescopic rod 11 that drives the movement of the filter screen 7. The telescopic end of the electric telescopic rod 11 is fixedly connected to the filter screen 7, and the driving end is fixed to the refining vessel 1. A liquid extraction pipe 8 is fixedly connected to the upper surface of the filter screen 7. The end of the liquid extraction pipe 8 away from the filter screen 7 extends out of the refining kettle 1 and is connected to the waste liquid tank 10.

[0029] When filter 7 reaches its first height, hydrochloric acid is introduced into the purification vessel 1 via the acid supply device. At this point, the purification vessel 1 contains acid and a solution containing crude sodium pyrithione. Under the action of the acid, sodium pyrithione in the solution is converted into 2-mercaptopyridine-N-oxide and precipitates out, while other impurities remain in the solution. During the precipitation of 2-mercaptopyridine-N-oxide, filter 7 remains above the liquid level in the purification vessel 1 to prevent 2-mercaptopyridine-N-oxide from precipitating above filter 7 and increasing the load on the electric telescopic rod 11. After the addition of acid, the residual sodium hydrosulfide in the solution generates hydrogen sulfide gas, which is then recycled by the gas treatment device. When filter 7 moves downward to its second height, it is below the liquid level in the purification vessel 1. The suction pipe 8 then pumps the solution containing impurities from the purification vessel 1 into the waste liquid tank 10, leaving only 2-mercaptopyridine-N-oxide in the purification vessel 1, thus purifying the 2-mercaptopyridine-N-oxide. The washing device supplies deionized water to the refining vessel 1 to wash away sodium chloride impurities. Sodium hydroxide solution is then passed into the refining vessel 1 via an alkali supply device, allowing the purification process of crude sodium pyridinethione to take place within the refining vessel 1. This minimizes the number of devices involved, eliminates the need for multiple material transfers, and reduces material loss.

[0030] Specifically, the extraction tube 8 has an elastic tube 12, which is vertically arranged and located inside the refining vessel 1. The elastic tube 12 can move with the filter screen 7. A rotating shaft 14 is provided inside the refining vessel 1. The top end of the rotating shaft 14 passes through the filter screen 7 and the top end of the refining vessel 1 and is connected to a motor 13. A stirring rod 15 is provided at the lower end of the rotating shaft 14. The stirring rod 15 and the filter screen 7 do not interfere with each other. Specifically, the stirring rod 15 is located below the second height of the filter screen 7. The stirring rod 15 can stir the liquid and accelerate the precipitation of 2-mercaptopyridine-N-oxide. An annular sleeve 16 is provided on the lower surface of the filter screen 7. The annular sleeve 16 is coaxially arranged with the rotating shaft 14, and a gap is left between the annular sleeve 16 and the rotating shaft 14. The inner surface of the annular sleeve 16 is circumferentially distributed with first bristles 17, which are in contact with the rotating shaft 14. When 2-mercaptopyridine-N-oxide precipitates under acidic conditions, it tends to stick to the rotating shaft 14, which can affect the normal movement of the filter screen 7. The first brush 17 scrapes off the 2-mercaptopyridine-N-oxide on the rotating shaft 14 to avoid obstructing the movement of the filter screen 7.

[0031] The inner wall of the refining vessel 1 is provided with several longitudinal slide rails 18. Each longitudinal slide rail 18 has a limiting block 29 at its top and bottom. The outer edge of the filter screen 7 has an inner concave wall 19 that matches the longitudinal slide rails 18. The longitudinal slide rails 18 guide the movement of the filter screen 7. A semi-annular sleeve 21 is provided on the lower surface of the inner concave wall 19. A second brush bristle 20 is provided on the inner surface of the semi-annular sleeve 21, and the second brush bristle 20 contacts the longitudinal slide rails 18. The second brush bristle 20 scrapes off the 2-mercaptopyridine-N-oxide on the longitudinal slide rails 18, preventing it from affecting the movement of the filter screen 7.

[0032] Specifically, the refining vessel 1 has a second liquid inlet 3 at its top. The acid supply device includes an acid supply tank 25, which is connected to the second liquid inlet 3 via an acid pipe 26. The acid pipe 26 is equipped with a second three-way valve 27. The washing device includes a washing tank 24, which is connected to one port of the second three-way valve 27 via a water pipe 31. The refining vessel 1 also has a gas outlet 4 at its top, through which gas enters the gas treatment device. The alkali supply device includes an alkali supply tank 32, and the refining vessel 1 also has an alkali outlet 5. The alkali supply tank 32 and the alkali outlet 5 are connected via an alkali pipe 33, which is equipped with an alkali valve 34. Along the liquid flow direction, the liquid extraction pipe 8 is connected in sequence to a liquid extraction pump 9 and a first three-way valve 22. One port of the first three-way valve 22 is connected to the washing tank 24 via a return pipe 23. The washing tank 24 contains deionized water, and the acid supply tank 25 contains hydrochloric acid. After the waste liquid is extracted from the refining vessel 1, 2-mercaptopyridine-N-oxide still contains sodium chloride impurities. Deionized water is added to the refining vessel 1 through the washing tank 24 to wash the 2-mercaptopyridine-N-oxide. The deionized water is then pumped back into the washing tank 24 using the extraction pipe 8 for deionization. The refining vessel 1 is equipped with a nitrogen inlet 30. Before extracting the waste liquid, nitrogen gas is introduced into the refining vessel 1 through the nitrogen inlet 30 to expel air. The air exits through the gas outlet 4 to prevent the oxidation of 2-mercaptopyridine-N-oxide. Hydrochloric acid is volatile, and the air contains hydrogen chloride gas, which cannot be directly discharged. Therefore, the air enters a gas treatment device through the gas outlet 4. The gas treatment device is a conventional method in this field and will not be described in detail here. The refining vessel 1 is equipped with a window 28 for observing the material inside the vessel.

[0033] Detailed operation process

[0034] The reaction system containing crude sodium pyrithione is added to the refining vessel 1 through inlet 2. The electric telescopic rod 11 is activated, causing the filter screen 7 to move upwards to the first height. The motor 13 is then activated, driving the rotating shaft 14 to rotate, which in turn drives the stirring rod 15 to rotate, stirring the liquid. The connection between the acid supply tank 25 and the refining vessel 1 is opened on the second three-way valve 27, and hydrochloric acid is added to the refining vessel 1. Under acidic conditions, sodium pyrithione is converted to 2-mercaptopyridine-N-oxide and precipitates from the solution. The generated hydrogen sulfide enters the gas treatment device for post-treatment through gas outlet 4. Then, nitrogen gas is introduced into the refining vessel 1 through nitrogen inlet 30 to purge the air from the refining vessel 1. The nitrogen supply is then stopped, and the air enters the gas treatment system.

[0035] After 2-mercaptopyridine-N-oxide is completely precipitated, motor 13 is turned off. The electric telescopic rod 11 is started, causing the filter screen 7 to move downwards. The first brush 17 scrapes off the 2-mercaptopyridine-N-oxide on the rotating shaft 14, and the filter screen 7 moves to the second height. The connection between the suction pipe 8 and the waste liquid tank 10 on the first three-way valve 22 is opened, and the suction pump 9 is turned on, allowing waste liquid to enter the waste liquid tank 10 from the suction pipe 8. After waste liquid extraction is complete, the electric telescopic rod 11 is started again, causing the filter screen 7 to rise. The connection between the washing tank 24 and the refining vessel 1 in the second three-way valve 27 is opened, adding deionized water from the washing tank 24 to the refining vessel 1. Motor 13 is started, causing the rotating shaft 14 to rotate, which in turn causes the stirring rod 15 to rotate. The stirring rod 15 stirs the mixture, and the deionized water washes the 2-mercaptopyridine-N-oxide. Then start the electric telescopic rod 11 to move the filter screen 7 to the second height, open the connection between the liquid pump 9 on the first three-way valve 22 and the washing tank 24, and the washed deionized water enters the return pipe 23 from the liquid pump pipe 8 and finally returns to the washing tank 24.

[0036] After washing, turn off the liquid pump 9, open the alkali valve 34, and add sodium hydroxide to the refining kettle 1 through the alkali supply tank 32. 2-mercaptopyridine-N-oxide regenerates sodium pyridinethione and dissolves in the solution to obtain purified sodium pyridinethione. The solution is then discharged from the liquid outlet 6 for the next process.

[0037] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. Furthermore, it should be understood that after reading the technical description of this utility model, those skilled in the art can make various alterations, modifications, and / or variations to this utility model, and all such equivalent forms also fall within the scope of protection defined by the appended claims.

Claims

1. A high-efficiency production apparatus for sodium pyrithione, characterized in that, The device includes a refining vessel (1), which is connected to an acid supply device, a washing device, an alkali supply device, and a gas treatment device. A filter screen (7) is provided inside the refining vessel (1). The filter screen (7) is horizontally arranged and can move between a first height and a second height. A liquid extraction pipe (8) is fixedly connected to the upper surface of the filter screen (7), and one end of the liquid extraction pipe (8) away from the filter screen (7) extends out of the refining vessel (1). At the first height, the filter screen (7) is higher than the liquid level inside the refining vessel (1); at the second height, the lower end of the suction pipe (8) is located inside the liquid in the refining vessel (1).

2. The high-efficiency production apparatus for sodium pyridinethione according to claim 1, characterized in that, The refining vessel (1) is vertically equipped with a rotating shaft (14). The top end of the rotating shaft (14) passes through the filter screen (7) and the top end of the refining vessel (1) and is connected to a motor (13). The lower end of the rotating shaft (14) is equipped with a stirring rod (15). The stirring rod (15) and the filter screen (7) do not interfere with each other.

3. The high-efficiency production apparatus for sodium pyridinethione according to claim 2, characterized in that, The filter screen (7) has an annular sleeve (16) on its lower surface. The annular sleeve (16) is coaxially arranged with the rotating shaft (14). There is a gap between the annular sleeve (16) and the rotating shaft (14). The inner surface of the annular sleeve (16) is circumferentially distributed with first bristles (17). The first bristles (17) are in contact with the rotating shaft (14).

4. The high-efficiency production apparatus for sodium pyrithione according to claim 1, characterized in that, The liquid extraction tube (8) has an elastic tube (12), which is located inside the refining vessel (1) and is vertically arranged.

5. The high-efficiency production apparatus for sodium pyrithione according to claim 1, characterized in that, The refining vessel (1) is equipped with an electric telescopic rod (11) that drives the filter screen (7) to move.

6. The high-efficiency production apparatus for sodium pyridinethione according to claim 1, characterized in that, The inner wall of the refining vessel (1) is provided with several longitudinal slide rails (18), and the top and bottom of the longitudinal slide rails (18) are provided with limiting blocks (29). The outer edge of the filter screen (7) is provided with an inner concave wall (19) that matches the longitudinal slide rails (18).

7. The high-efficiency production apparatus for sodium pyridinethione according to claim 6, characterized in that, The lower surface of the concave wall (19) is provided with a semi-annular sleeve (21), and the inner surface of the semi-annular sleeve (21) is provided with a second brush (20), which contacts the longitudinal slide rail (18).

8. The high-efficiency production apparatus for sodium pyrithione according to claim 1, characterized in that, The end of the extraction tube (8) extending outside the refining vessel (1) is connected to a waste liquid tank (10).

9. The high-efficiency production apparatus for sodium pyrithione according to claim 1, characterized in that, Along the direction of liquid flow, the liquid extraction pipe (8) is sequentially equipped with a liquid extraction pump (9) and a first three-way valve (22). The first three-way valve (22) is connected to the washing device through the return pipe (23).

10. The high-efficiency production apparatus for sodium pyridinethione according to claim 1, characterized in that, The refining vessel (1) is equipped with a nitrogen inlet (30).

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