Phosphoric acid adding system in hydrogen peroxide production

Abstract

The utility model provides a phosphoric acid adding system in hydrogen peroxide production, comprising: a strong phosphoric acid storage tank, an outlet of the strong phosphoric acid storage tank is communicated with a strong phosphoric acid delivery pipe, and the strong phosphoric acid delivery pipe is provided with a strong phosphoric acid pump; an outlet of the pure water storage tank is communicated with a water pipe and a water pump; a positive pressure inlet of the venturi tube is communicated with the pure water storage tank, a negative pressure inlet of the venturi tube is communicated with the strong phosphoric acid conveying pipe, and an outlet end of the venturi tube is sequentially communicated with a dilute phosphoric acid pump, a mixer and a working storage tank through a mixing pipeline; a first weighing sensor and a first pH meter are arranged on the strong phosphoric acid storage tank, and a second weighing sensor is arranged on the pure water storage tank; a second pH meter is arranged at the outlet end of the mixer, and a third pH meter is arranged at the position, close to the working storage tank, of the mixing pipeline. The phosphoric acid uniformity and the pH value stability are improved.

Description

TECHNICAL FIELD

[0001] The application relates to a hydrogen peroxide production technology field, in particular to a phosphoric acid adding system in hydrogen peroxide production. BACKGROUND

[0002] Hydrogen peroxide is a strong oxidizing substance, but it is reduced when it meets a stronger oxidizing agent, such as potassium permanganate, chlorine, etc. It is relatively active in chemical properties and can participate in decomposition, molecular addition, substitution, oxidation-reduction and other reactions. At present, hydrogen peroxide is usually produced by the anthraquinone method.

[0003] In the anthraquinone hydrogen peroxide production device, dilute phosphoric acid solution needs to be added at many positions to make part of the production system acidic to prevent hydrogen peroxide from being decomposed by alkali and thus causing hydrogen peroxide decomposition accidents.

[0004] In the prior art, concentrated phosphoric acid is diluted with water to obtain dilute phosphoric acid, and then the dilute phosphoric acid is transported to the production process that needs to be adjusted in pH value. However, the concentrated phosphoric acid and water are simply stirred and mixed before being directly used in the transportation process, so that the dilute phosphoric acid is not mixed uniformly, the pH value of the dilute phosphoric acid is unstable, and the stability of the hydrogen peroxide production system is affected. CONTENT OF THE INVENTION

[0005] The application provides a phosphoric acid adding system in hydrogen peroxide production to solve the above problems mentioned in the background.

[0006] The application provides a phosphoric acid adding system in hydrogen peroxide production, which comprises:

[0007] A concentrated phosphoric acid storage tank, an outlet of the concentrated phosphoric acid storage tank is communicated with a concentrated phosphoric acid conveying pipe, and a concentrated phosphoric acid pump is arranged on the concentrated phosphoric acid conveying pipe;

[0008] A pure water storage tank, an outlet of the pure water storage tank is communicated with a water pipe and a water pump;

[0009] A Venturi tube, a positive pressure inlet of the Venturi tube is communicated with the pure water storage tank, a negative pressure inlet of the Venturi tube is communicated with the concentrated phosphoric acid conveying pipe, and an outlet end of the Venturi tube is sequentially communicated with a dilute phosphoric acid pump, a mixer and a working storage tank through a mixing pipeline;

[0010] A first weighing sensor and a first pH meter are arranged on the concentrated phosphoric acid storage tank, and a second weighing sensor is arranged on the pure water storage tank;

[0011] A second pH meter is arranged at an outlet end of the mixer, and a third pH meter is arranged at a position close to the working storage tank in the mixing pipeline.

[0012] Optionally, the mixer comprises an outer pipe body, an inner pipe body and a tapered pipe body.

[0013] The outer pipe body is coaxially arranged with the inner pipe body and is sleeved outside the inner pipe body, the end with the larger diameter of the taper pipe body is connected with the inlet end of the outer pipe body, and the end with the smaller diameter of the taper pipe body is connected with the inlet end of the inner pipe body.

[0014] The inner pipe body is provided with a plurality of flow guide units, the flow guide units sequentially include a first flow guide plate, a first flow guide port, a second flow guide port, a second flow guide plate and a spoiler in the material flow direction, the first flow guide port and the second flow guide port are arranged on the two sides of the inner pipe body, the first flow guide plate is located at the first flow guide port, and the plate surface of the first flow guide plate has an angle with the material flow direction, the second flow guide plate is symmetrically arranged with the first flow guide plate about the vertical direction, and the spoiler is located on the side wall of the inner pipe body between the second flow guide plate and the first flow guide plate.

[0015] Optionally, the angle between the plate surface of the first flow guide plate and the material flow direction is 30-60°.

[0016] Optionally, the ratio of the diameter of the inner pipe body to the diameter of the outer pipe body is 1 / 2-3 / 4.

[0017] Optionally, the inner pipe body is provided with diffusion sections at intervals, and the inner diameter of the diffusion section is greater than the inner diameter of the inner pipe body.

[0018] Optionally, a screw is fixedly arranged on the central axis in the inner pipe body through a connecting rod, one end of the screw close to the inlet of the mixer is connected with the end with the larger diameter of the taper pipe body through a connecting rod, and the other end of the screw close to the outlet of the mixer is connected with the inner pipe body through a connecting rod.

[0019] Optionally, the concentrated phosphoric acid tank and the pure water tank are provided with an insulation jacket outside.

[0020] Optionally, the phosphoric acid adding system is further provided with a control unit, and the control unit is connected with the concentrated phosphoric acid pump, the water pump, the dilute phosphoric acid pump, the first weighing sensor, the second weighing sensor, the first pH meter, the second pH meter and the third pH meter.

[0021] The phosphoric acid adding system provided by the application realizes the preparation and addition of dilute phosphoric acid, and has the following beneficial effects compared with the prior art.

[0022] (1) Firstly, the concentrated phosphoric acid and pure water are mixed by the Venturi tube, and then the diluted phosphoric acid obtained after the initial mixing is mixed again by the mixer under the power of the diluted phosphoric acid pump, and then is sent to the working tank, so that the diluted phosphoric acid is more uniform. By setting the first weighing sensor, the first pH meter, the second weighing sensor, the second pH meter and the third pH meter, the weight of the output concentrated phosphoric acid and pure water and the pH value of the diluted phosphoric acid entering the working tank can be known whether it meets the required value of the reaction, so that the addition amount of the concentrated phosphoric acid and the pure water is more accurate, which is more helpful to improve the stability of the pH value of the prepared diluted phosphoric acid, and then the hydrogen peroxide production system runs safely and stably, and the efficiency and quality of the hydrogen peroxide production are improved.

[0023] (2) By setting the flow guide unit, including the first flow guide plate, the first flow guide port, the second flow guide port, the second flow guide plate and the spoiler, after the diluted phosphoric acid enters the inner pipe body, part of it flows out through the first flow guide port on both sides and enters the space between the outer pipe body and the inner pipe body, and continues to collide with the spoiler in the flowing process, which further improves the mixing degree of the diluted phosphoric acid. In the continuous flowing process, part of the diluted phosphoric acid outside the inner pipe body collides with the second flow guide plate and enters the inner pipe body again through the flow guide of the second flow guide plate and mixes with the diluted phosphoric acid in the inner pipe body. In this way, after the diluted phosphoric acid passes through the spoilers of multiple flow guide units and is mixed in the mixer, the mixing uniformity of the diluted phosphoric acid is further improved, so that the diluted phosphoric acid output from the mixer has a stable pH value. In this way, the diluted phosphoric acid entering the working tank can provide a stable pH value for the reaction system in the reaction, thereby improving the safety and stability of the hydrogen peroxide production system.

[0024] (3) The application also has a control unit, which improves the automation degree of the phosphoric acid adding process.

[0025] (4) The application can not only be applied to the phosphoric acid adding process, but also can be applied to other liquid-liquid and liquid-gas mixing. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating laborious work.

[0027] Figure 1 The structure schematic diagram of the hydrogen peroxide production phosphoric acid adding system provided by an embodiment of the present application;

[0028] Figure 2 The top view structure schematic diagram of the mixer provided by an embodiment of the present application;

[0029] Figure 3 A top view structural schematic diagram of a mixer provided for another embodiment of the present application;

[0030] Figure 4 A connection schematic diagram of a screw provided for an embodiment of the present application;

[0031] Figure 5 A connection schematic diagram of a control unit provided for an embodiment of the present application;

[0032] Explanation of reference signs:

[0033] 1: concentrated phosphoric acid storage tank, 2: pure water storage tank, 3: Venturi tube, 4: mixing pipeline, 5: mixer, 7: working storage tank, 8: control unit, 9: dilute phosphoric acid pump, 110: concentrated phosphoric acid delivery pipe, 111: concentrated phosphoric acid pump, 120: first weighing sensor, 130: first pH meter, 201: water pump, 210: water pipe, 220: second weighing sensor, 410: second pH meter, 420: third pH meter, 430: bypass pipeline, 431: bypass valve, 510: outer pipe body, 520: inner pipe body, 521: first flow guide plate, 522: first flow guide opening, 530: tapered pipe body, 531: second flow guide opening, 532: second flow guide plate, 540: spoiler, 550: screw, 551: connecting rod, 560: diffusion section. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the scope of protection of the present application.

[0035] As shown in Figure 1 The present application provides a phosphoric acid adding system in hydrogen peroxide production, which comprises:

[0036] a concentrated phosphoric acid storage tank 1, an outlet of the concentrated phosphoric acid storage tank 1 being communicated with a concentrated phosphoric acid delivery pipe 110, and a concentrated phosphoric acid pump 111 being arranged on the concentrated phosphoric acid delivery pipe 110;

[0037] a pure water storage tank 2, an outlet of the pure water storage tank 2 being communicated with a water pipe 210 and a water pump 201;

[0038] a Venturi tube 3, a positive pressure inlet of the Venturi tube 3 being communicated with the pure water storage tank 2, a negative pressure inlet of the Venturi tube 3 being communicated with the concentrated phosphoric acid delivery pipe 110, and an outlet end of the Venturi tube 3 being communicated with a dilute phosphoric acid pump 9, a mixer 5 and a working storage tank 7 in sequence through a mixing pipeline 4;

[0039] The concentrated phosphoric acid storage tank 1 is provided with a first weighing sensor 120 and a first pH meter 130, and the pure water storage tank 2 is provided with a second weighing sensor 220.

[0040] The outlet end of the mixer 5 is provided with a second pH meter 410, and the mixing pipeline 4 is provided with a third pH meter 420 near the working storage tank 7.

[0041] Specifically, the concentrated phosphoric acid storage tank 1 is used for storing concentrated phosphoric acid, the pure water storage tank 2 is used for storing pure water, the concentrated phosphoric acid is pumped out by the concentrated phosphoric acid pump 111 and is input into the Venturi tube 3 through the negative pressure inlet of the Venturi tube 3 by the concentrated phosphoric acid delivery pipe 110, and the pure water in the pure water storage tank 2 is pumped out by the water pump 201 and is input into the Venturi tube 3 through the positive pressure inlet of the Venturi tube 3, and the concentrated phosphoric acid and the pure water are mixed in the Venturi tube 3. After the initial mixing, the obtained dilute phosphoric acid is transported to the mixer 5 through the mixing pipeline 4 under the power of the dilute phosphoric acid pump 9 for re-mixing, and then enters the working storage tank 7, so that the dilute phosphoric acid is more uniform.

[0042] The concentrated phosphoric acid storage tank 1 is provided with a first weighing sensor 120 and a first pH meter 130, and the pure water storage tank 2 is provided with a second weighing sensor 220, the first pH meter 130 is used for detecting the pH value of the concentrated phosphoric acid in the concentrated phosphoric acid storage tank 1 in real time, according to the pH value and the weight of the dilute phosphoric acid required to be configured in the working storage tank 7, the amount of the required concentrated phosphoric acid and pure water can be calculated, and the weight of the output concentrated phosphoric acid in the concentrated phosphoric acid storage tank 1 can be directly known through the first weighing sensor 120, and the weight of the output pure water can be known according to the second weighing sensor 220, so that the adding amount of the concentrated phosphoric acid and the pure water is more accurate, which is helpful to the stability of the pH value of the dilute phosphoric acid.

[0043] The outlet end of the mixer 5 is provided with a second pH meter 410, and the mixing pipeline 4 is provided with a third pH meter 420 near the working storage tank 7, for real-time control of the stability of the pH value of the dilute phosphoric acid entering the working storage tank 7.

[0044] Further, the bypass pipeline 430 is communicated between the third pH meter 420 and the working storage tank 7 on the mixing pipeline 4, the bypass valve 431 is arranged on the bypass pipeline 430, if the difference between the measured values of the second pH meter 410 and the third pH meter 420 is less than or equal to a preset value (such as 0.3), the phosphoric acid adding system continues to operate, if the difference between the measured values of the second pH meter 410 and the third pH meter 420 is greater than the preset value (such as 0.3), the bypass valve 431 is opened, and the dilute phosphoric acid in the mixing pipeline 4 is guided out through the bypass pipeline 430, which further ensures the stability of the pH value of the dilute phosphoric acid entering the working storage tank 7, avoids the decomposition of hydrogen peroxide due to the unsuitable acid-base environment, and thus makes the hydrogen peroxide production system safe and stable, improves the efficiency and quality of the hydrogen peroxide production.

[0045] The application example realizes preparation and addition of dilute phosphoric acid through the above scheme. The concentrated phosphoric acid is initially mixed with pure water through the Venturi tube, and then the obtained dilute phosphoric acid after initial mixing is mixed again through the mixer under the power of the dilute phosphoric acid pump, and then is delivered to the working tank, so that the dilute phosphoric acid is more uniform. The first weighing sensor, the first pH meter, the second weighing sensor, the second pH meter, and the third pH meter are arranged, so that the weight of the output concentrated phosphoric acid and pure water and the pH value of the dilute phosphoric acid entering the working tank can be known whether it meets the required value of the reaction, so that the addition amount of the concentrated phosphoric acid and the pure water is more accurate, which is more helpful to improve the stability of the pH value of the prepared dilute phosphoric acid, and then the hydrogen peroxide production system is safe and stable, and the efficiency and quality of the hydrogen peroxide production are improved.

[0046] As shown in Figure 2 Optionally, the mixer 5 includes an outer pipe body 510, an inner pipe body 520, and a tapered pipe body 530.

[0047] The outer pipe body 510 is coaxially arranged with the inner pipe body 520 and is arranged outside the inner pipe body 520. The tapered pipe body 530 is connected to the inlet end of the outer pipe body 510 at the end with a larger diameter, and is connected to the inlet end of the inner pipe body 520 at the end with a smaller diameter.

[0048] The inner pipe body 520 is provided with a plurality of flow guide units. The flow guide units include a first flow guide plate 521, a first flow guide port 522, a second flow guide port 531, a second flow guide plate 532, and a spoiler 540 in sequence along the material flow direction. The first flow guide port 522 and the second flow guide port 531 are arranged on both sides of the inner pipe body 520. The first flow guide plate 521 is located at the first flow guide port 522, and the plate surface of the first flow guide plate 521 forms an angle with the material flow direction. The second flow guide plate 532 is symmetrically arranged with the first flow guide plate 521 about the vertical direction. The spoiler 540 is arranged on the outer sidewall of the inner pipe body 520 between the second flow guide plate 532 and the first flow guide plate 521.

[0049] Specifically, the dilute phosphoric acid obtained after initial mixing through the Venturi tube 3 is delivered to the mixer 5 through the mixing pipeline 4 for re-mixing.

[0050] Mixer 5 includes an outer tube 510, an inner tube 520, and a conical tube 530. The initially mixed dilute phosphoric acid enters the inner tube 520 through the conical tube 530 for further mixing. The inner tube 520 is equipped with multiple flow guiding units to turbulent the flow of the dilute phosphoric acid, improving the mixing uniformity. The initially mixed dilute phosphoric acid flows from the larger diameter end of the conical tube 530 to the smaller diameter end and enters the inner tube 520. During this process, the flow cross-section of the dilute phosphoric acid gradually decreases, increasing its flow velocity and kinetic energy. This contributes to better power and speed in subsequent mixing processes, improving mixing efficiency.

[0051] The flow guiding unit, along the material flow direction, includes a first guide plate 521, a first guide port 522, a second guide port 531, a second guide plate 532, and a baffle plate 540. After dilute phosphoric acid enters the inner tube 520, a portion flows out through the first guide ports 522 on both sides and enters the space between the outer tube 510 and the inner tube 520. During the flow of dilute phosphoric acid outside the inner tube 520, it continues to collide with the baffle plate 540 on the outer wall of the inner tube 520, further increasing the mixing degree of the dilute phosphoric acid. As the flow continues, the dilute phosphoric acid outside the inner tube 520... A portion of the dilute phosphoric acid collides with the second guide plate 532 and is guided back into the inner tube 520 through the second guide plate 532, where it mixes with the dilute phosphoric acid in the inner tube 520. In this way, after the dilute phosphoric acid is turbulent and mixed by multiple guide units in the mixer 5, the mixing uniformity of the dilute phosphoric acid is further improved, so that the dilute phosphoric acid output from the mixer 5 has a stable pH value. This allows the dilute phosphoric acid entering the working storage tank 7 to provide a stable acidity and alkalinity for the reaction system during the reaction, thereby improving the safety and stability of the hydrogen peroxide production system.

[0052] Furthermore, the mixer 5 provided in this application does not require the consumption of electrical energy or other energy resources, thereby improving mixing efficiency while reducing energy consumption and lowering costs, resulting in significant economic benefits.

[0053] Optionally, the angle between the surface of the first guide plate 521 and the material flow direction is 30-60°.

[0054] Specifically, by limiting the angle between the surface of the first guide plate 521 and the material flow direction, the first guide plate 521 and the second guide plate 532 can promote the mixing process of dilute phosphoric acid, while avoiding the increase in flow resistance of dilute phosphoric acid due to an excessively large angle, thus improving the mixing efficiency.

[0055] Optionally, the ratio of the diameter of the inner tube 520 to the diameter of the outer tube 510 is 1 / 2 to 3 / 4.

[0056] like Figure 3As shown, optionally, the inner tube body 520 is provided with diffusion sections 560 at intervals, and the inner diameter of the diffusion sections 560 is greater than that of the inner tube body 520.

[0057] Specifically, after the diluted phosphoric acid passes through a flow guide unit, the diluted phosphoric acid is mixed again in the entire cross section of the inner tube body 520 through the diffusion sections 560, thereby further improving the mixing efficiency.

[0058] As shown, Figure 4 As shown, optionally, a screw rod 550 is fixedly arranged on the central axis of the inner tube body 520 through a connecting rod 551, one end of the screw rod 550 close to the inlet of the mixer 5 is connected to the larger-diameter end of the conical tube body 530 through the connecting rod 551, and the other end of the screw rod 550 close to the outlet of the mixer 5 is connected to the inner tube body 520 through the connecting rod 551.

[0059] Specifically, the inner tube body 520 is provided with the screw rod 550, and the diluted phosphoric acid in the inner tube body 520 passes through the screw rod 550 in a spiral shape, thereby further improving the degree of turbulent flow and further improving the uniformity of the diluted phosphoric acid and the stability of pH.

[0060] Optionally, the concentrated phosphoric acid tank 1 and the pure water tank 2 are provided with heat preservation jackets outside, which can avoid the freezing of the concentrated phosphoric acid and the pure water when the temperature is too low.

[0061] As shown, Figure 5 As shown, optionally, the phosphoric acid adding system is further provided with a control unit 8, and the control unit 8 is connected with the concentrated phosphoric acid pump 111, the water pump 201, the diluted phosphoric acid pump 9, the first weighing sensor 120, the second weighing sensor 220, the first pH meter 130, the second pH meter 410, and the third pH meter 420.

[0062] Specifically, by inputting a preset pH value into the control unit 8, the control unit 8 can calculate the required amount of concentrated phosphoric acid and pure water according to the input preset pH value and the value of the first pH meter 130, and then control the start and stop of the concentrated phosphoric acid pump 111, the water pump 201, and the diluted phosphoric acid pump 9 by receiving the weight signals of the first weighing sensor 120 and the second weighing sensor 220.

[0063] Further, the control unit 8 is also connected with the bypass valve 431, and the control unit 8 controls the opening and closing of the bypass valve 431 according to the difference between the measured values of the second pH meter 410 and the third pH meter 420. If the difference between the measured values of the second pH meter 410 and the third pH meter 420 received by the control unit 8 is less than or equal to 0.3, the adding system continues to operate, and if the difference between the measured values of the second pH meter 410 and the third pH meter 420 received by the control unit 8 is greater than 0.3, the control unit 8 opens the bypass valve 431, and the diluted phosphoric acid in the mixing pipeline 4 is guided out through the bypass pipeline 430.

[0064] The technical solutions of the present application are illustrated in detail below with specific examples.

[0065] The operation flow of the phosphoric acid adding system in the hydrogen peroxide production in the present embodiment is as follows:

[0066] According to the amount and pH value of the dilute phosphoric acid required in different processes of the hydrogen peroxide reaction, the preset weight and pH value of the dilute phosphoric acid are set, and the control unit 8 can calculate the required weight of the concentrated phosphoric acid and pure water according to the input preset pH value and preset weight and the value received by the first pH meter 130 in the concentrated phosphoric acid storage tank 1. The control unit 8 controls the opening of the concentrated phosphoric acid pump 111, the dilute phosphoric acid pump 9 and the water pump 201, and the concentrated phosphoric acid is input into the Venturi tube 3 from the negative pressure inlet of the Venturi tube 3 through the concentrated phosphoric acid delivery pipe 110, and the pure water in the pure water storage tank 2 is pumped out by the water pump 201 and input into the Venturi tube 3 from the positive pressure inlet of the Venturi tube 3, and the concentrated phosphoric acid and the pure water are initially mixed in the Venturi tube 3.

[0067] After the initial mixing in the Venturi tube 3, the obtained dilute phosphoric acid is transported to the mixer 5 through the mixing pipeline 4 for re-mixing. The dilute phosphoric acid after the initial mixing flows from the larger-diameter end of the cone tube body 530 to the smaller-diameter end and enters the inner tube body 520, a part of which flows out through the first flow guide port 522 on both sides and enters the space between the outer tube body 510 and the inner tube body 520, and the dilute phosphoric acid outside the inner tube body 520 continues to collide with the spoiler 540 on the outer sidewall of the inner tube body 520 during the flow process, thereby further improving the mixing degree of the dilute phosphoric acid. During the continuous flow, a part of the dilute phosphoric acid outside the inner tube body 520 collides with the second flow guide plate 532 and re-enters the inner tube body 520 through the flow guidance of the second flow guide plate 532, and mixes with the dilute phosphoric acid in the inner tube body 520. In this way, after the dilute phosphoric acid passes through multiple flow guide units for turbulence and mixing in the mixer 5, the uniformity of the dilute phosphoric acid is further improved.

[0068] After the dilute phosphoric acid is mixed by the flow guide unit, it is re-mixed by the diffusion section 560 in the entire cross section of the inner tube body 520, and the dilute phosphoric acid in the inner tube body 520 is further mixed by the spiral of the screw rod 550. If the difference between the measured values of the second pH meter 410 and the third pH meter 420 received by the control unit 8 is less than or equal to 0.3, the adding system continues to operate, and if the difference between the measured values of the second pH meter 410 and the third pH meter 420 received by the control unit 8 is greater than 0.3, the control unit 8 opens the bypass valve 431 to guide the dilute phosphoric acid in the mixing pipeline 4 out through the bypass pipeline 430.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A phosphoric acid addition system for hydrogen peroxide production, characterized in that, include: A concentrated phosphoric acid storage tank (1) is provided with its outlet connected to a concentrated phosphoric acid delivery pipe (110), and a concentrated phosphoric acid pump (111) is provided on the concentrated phosphoric acid delivery pipe (110). Pure water storage tank (2), the outlet of which is connected to a water pipe (210) and a water pump (201); Venturi tube (3), the positive pressure inlet of the Venturi tube (3) is connected to the pure water storage tank (2), the negative pressure inlet of the Venturi tube (3) is connected to the concentrated phosphoric acid delivery pipe (110), and the outlet end of the Venturi tube (3) is connected in sequence to the dilute phosphoric acid pump (9), the mixer (5) and the working storage tank (7) through the mixing pipeline (4). The concentrated phosphoric acid storage tank (1) is equipped with a first weighing sensor (120) and a first pH meter (130), and the pure water storage tank (2) is equipped with a second weighing sensor (220). A second pH meter (410) is provided at the outlet end of the mixer (5), and a third pH meter (420) is provided on the mixing pipeline (4) near the working storage tank (7).

2. The phosphoric acid addition system in hydrogen peroxide production according to claim 1, characterized in that, The mixer (5) includes an outer tube (510), an inner tube (520), and a conical tube (530); The outer tube (510) is coaxially arranged with the inner tube (520) and sleeved outside the inner tube (520). The larger diameter end of the tapered tube (530) is connected to the inlet end of the outer tube (510), and the smaller diameter end of the tapered tube (530) is connected to the inlet end of the inner tube (520). The inner tube (520) is provided with a plurality of flow guiding units. The flow guiding units include, in sequence along the material flow direction, a first flow guiding plate (521), a first flow guiding port (522), a second flow guiding port (531), a second flow guiding plate (532), and a baffle plate (540). The first flow guiding port (522) and the second flow guiding port (531) are opened on both sides of the inner tube (520). The first flow guiding plate (521) is located at the first flow guiding port (522), and the plate surface of the first flow guiding plate (521) has an angle with the material flow direction. The second flow guiding plate (532) and the first flow guiding plate (521) are symmetrically arranged about the vertical direction. The baffle plate (540) is located on the side wall of the inner tube (520) between the second flow guiding plate (532) and the first flow guiding plate (521).

3. The phosphoric acid addition system in hydrogen peroxide production according to claim 2, characterized in that, The angle between the surface of the first guide plate (521) and the material flow direction is 30-60°.

4. The phosphoric acid addition system in hydrogen peroxide production according to claim 2, characterized in that, The ratio of the diameter of the inner tube (520) to the diameter of the outer tube (510) is 1 / 2 to 3 / 4.

5. The phosphoric acid addition system in hydrogen peroxide production according to claim 2, characterized in that, The inner tube (520) is provided with diffuser sections (560) at intervals, and the inner diameter of the diffuser section (560) is larger than the inner diameter of the inner tube (520).

6. The phosphoric acid addition system in hydrogen peroxide production according to claim 2, characterized in that, A screw (550) is fixedly installed on the central axis inside the inner tube (520) via a connecting rod (551). The end of the screw (550) near the inlet of the mixer (5) is connected to the end of the tapered tube (530) with a larger diameter via the connecting rod (551). The end of the screw (550) near the outlet of the mixer (5) is connected to the inner tube (520) via the connecting rod (551).

7. The phosphoric acid addition system in hydrogen peroxide production according to claim 6, characterized in that, The concentrated phosphoric acid storage tank (1) and the pure water storage tank (2) are equipped with heat-insulating jackets.

8. The phosphoric acid addition system for hydrogen peroxide production according to any one of claims 1-7, characterized in that, The phosphoric acid addition system is also provided with a control unit (8), which is connected to the concentrated phosphoric acid pump (111), the water pump (201), the dilute phosphoric acid pump (9), the first weighing sensor (120), the second weighing sensor (220), the first pH meter (130), the second pH meter (410), and the third pH meter (420), respectively.

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