Venturi jet pump structure and bleaching method

Abstract

The invention provides a Venturi jet pump structure and a bleaching method.The Venturi jet pump structure comprises a support, an outer body, a suction guide pipe and a plugging head, the outer body is used for being fixedly installed on the support, an installation hole is formed in the left side of the outer body, and a first taper hole and a second taper hole are formed in the right side of the outer body; the large end of the first taper hole is connected with the mounting hole; the small end of the second taper hole is communicated with the first taper hole through the connecting hole; the plugging head is mounted in the mounting hole, a first round hole, a third conical hole and a second round hole are sequentially formed in the plugging head, and the hole diameter of the second round hole is larger than that of the connecting hole; the plugging head is in sealed connection with the external main body; a suction hole is formed in the outer body, the suction catheter is installed on the outer body and communicated with the suction hole, and the end of the plugging head and the first conical hole form a negative pressure cavity. The invention solves the technical problems of high maintenance cost, high safety and environmental protection risk and quality risk in the current bleaching reaction.

Description

Technical Field

[0001] The invention relates to the field of wet-process phosphoric acid preparation, and in particular to a Venturi jet pump structure and a bleaching method. Background Art

[0002] The wet process of phosphoric acid purification production uses the extraction reaction of organic phase (solvent) and inorganic phase (phosphoric acid) for mass transfer, so that the empty solvent is in contact with the organic solvent, and most of the phosphoric acid enters the organic phase after the extraction feed acid is extracted with the organic solvent, and most of the impurities remain in the water phase. After a series of processes such as stripping, concentration, and decolorization, the product is produced. However, the product contains organic impurities that cannot meet the product index. It is necessary to remove the organic impurities in the acid by redox reaction of high-temperature defluorinated acid and hydrogen peroxide after heating. The original design is a bleaching tower. The bleaching tower has high requirements for the medium environment (high acid concentration, high temperature and strong oxidizing property of the system). The design uses steel lining polytetrafluoroethylene material, which is very easy to corrode and perforate during use, and frequently restricts the production load of the purified phosphoric acid device. At the same time, in order to increase the reaction residence time, the design uses ball rings as fillers. Due to the aging of the ball rings, the overflow pipe of the bleaching tower is blocked and the replacement price is high, which frequently restricts the production load.

[0003] The invention with announcement number: CN111003697B discloses a high-purity phosphoric acid bleaching process, comprising the following steps: heating defluorinated acid to 110-130 degrees Celsius and feeding it into a microreactor; the defluorinated acid is mixed with hydrogen peroxide in the microreactor for bleaching and then fed to a gas-liquid separator to separate and obtain high-purity phosphoric acid. The process disclosed in the present invention has the advantages of high reaction efficiency and sufficient reflection. The high-purity phosphoric acid obtained by the invention has a chromaticity of ≤20 dark blue, a TOC content in phosphoric acid of ≤40ppm, and an organic impurity removal rate of 65%. The purified phosphoric acid with a concentration of not less than 85% generated by the process can meet the quality requirements of industrial-grade phosphoric acid and food-grade phosphoric acid, and has good market returns.

[0004] At present, wet purification of phosphoric acid bleaching mainly adopts a production mode in which high-temperature defluorinated acid and hydrogen peroxide are passed through a stainless steel microreactor; the organic impurities in phosphoric acid are removed by fully mixing and contacting to produce a redox reaction. This bleaching reaction method has a high reaction temperature, and the redox reaction is relatively violent and accompanied by heat release, which leads to serious corrosion and leakage of the stainless steel box of the microreactor. The metal ions in the product acid will increase, which may cause quality problems and safety and environmental problems. At the same time, the purchase investment of the stainless steel microreactor is relatively large. Summary of the invention

[0005] The purpose of the present invention is to provide a Venturi jet pump structure and a bleaching method, mainly to solve the technical difficulties of high maintenance cost, great safety and environmental protection risks and quality risks in the current bleaching reaction.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A bleaching method, comprising bleaching using the following system, wherein the system comprises a delivery pump, a first placement tank, a second placement tank, a first heating device and a jet pump, wherein the first placement tank is used to place defluorinated acid, and the second placement tank is used to place hydrogen peroxide.

[0008] The jet pump comprises a bracket, an external body, a suction conduit and a plugging head, wherein the external body is used for fixed installation on the bracket, a mounting hole is arranged on the left side of the external body, and a first tapered hole and a second tapered hole are arranged on the right side, the large end of the first tapered hole is connected to the mounting hole, and the small end of the second tapered hole is connected to the first tapered hole through a connecting hole;

[0009] The plugging head is installed in the installation hole, and a first circular hole, a third conical hole and a second circular hole are sequentially arranged inside the plugging head, and the aperture of the second circular hole is larger than the aperture of the connecting hole; a sealing connection is arranged between the plugging head and the external body;

[0010] The outer body is provided with a suction hole, the suction catheter is installed on the outer body and communicated with the suction hole, the end of the plugging head and the first conical hole form a negative pressure chamber. The first placement groove is used to connect with the plugging head, the second placement groove is used to connect with the suction catheter, a first heating device is provided between the first placement groove and the plugging head, the delivery pump is provided between the first placement groove and the first heating device, and the jet pump is connected to a separator.

[0011] Wherein, the plugging head is connected to the mounting hole through threads.

[0012] The first placement groove is used to be connected to the plugging head, the second placement groove is used to be connected to the suction catheter, a first heating device is arranged between the first placement groove and the plugging head, and the jet pump is connected to a separator.

[0013] Among them, the mounting hole is a stepped hole.

[0014] Furthermore, a slope is provided on one side of the plugging head end close to the first conical surface.

[0015] Preferably, connecting flanges are provided on both sides of the outer body.

[0016] In actual use, the flow volume ratio of defluorinated acid to hydrogen peroxide is 30:1.

[0017] Wherein, the separator is a centrifugal separator.

[0018] Furthermore, the concentration of hydrogen peroxide is 27%-28%.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In actual use, the invention realizes full mixing of defluorinated acid and hydrogen peroxide by means of a venturi jet pump, high-temperature defluorinated acid is delivered to the inlet of the venturi jet pump by a delivery pump, and the high-speed acid increases rapidly and reduces pressure after passing through the diameter change of the venturi tube, and vacuum is formed at the rear of the acid mist cone sprayed from the nozzle, and external hydrogen peroxide is continuously sucked into the suction conduit from the hydrogen peroxide inlet, and the newly sucked hydrogen peroxide collides and mixes with the acid mist cone in the negative pressure chamber, and is sprayed out from the jet port along with the acid mist, thereby realizing full mixing of defluorinated acid and hydrogen peroxide; compared with the existing microreactor, the invention has fewer sealing points, effectively avoids safety and environmental protection accidents caused by leakage due to redox reaction in a high-temperature environment, and improves the use safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is the overall principle diagram of the present invention.

[0023] Figure 2 This is one of the schematic diagrams of the structure of the Venturi jet pump of the present invention.

[0024] Figure 3 This is the second schematic diagram of the structure of the Venturi jet pump of the present invention.

[0025] Reference numerals:

[0026] 101 delivery pump, 102 first placement slot, 103 second placement slot, 104 first heating device, 105 jet pump, 106 bracket, 107 external body, 108 suction catheter, 109 plugging head, 110 mounting hole, 111 first conical hole, 112 second conical hole, 113 first circular hole, 114 third conical hole, 115 second circular hole, 116 suction hole, 117 negative pressure chamber, 118 inclined surface, 119 first plugging head, 120 second plugging head, 121 first mounting hole, 122 replacement head, 123 first conical auxiliary hole, 124 connecting hole, 125 separator. DETAILED DESCRIPTION

[0027] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0028] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 a limitation on the embodiments of the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0031] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] The disclosure below provides many different embodiments or examples to implement different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present invention. In addition, the embodiments of the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0033] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] Embodiment 1

[0035] See also Figure 1-Figure 3 This embodiment discloses a bleaching method, including using the following system for bleaching, the system including a delivery pump 101, a first placement tank 102, a second placement tank 103, a first heating device 104 and a jet pump 105, the first placement tank 102 is used to place defluorinated acid, and the second placement tank 103 is used to place hydrogen peroxide;

[0036] The jet pump 105 is a Venturi jet pump 105, and its structure is as follows:

[0037] The jet pump 105 includes a bracket 106, an outer body 107, a suction conduit 108 and a plugging head 109. The outer body 107 is used to be fixedly mounted on the bracket 106. The outer body 107 is provided with a mounting hole 110 on the left side, and a first tapered hole 111 and a second tapered hole 112 on the right side. The large end of the first tapered hole 111 is connected to the mounting hole 110, and the small end of the second tapered hole 112 is connected to the first tapered hole 111 through a connecting hole 124.

[0038] The plugging head 109 is installed in the installation hole 110, and a first circular hole 113, a third tapered hole 114 and a second circular hole 115 are sequentially arranged inside the plugging head 109, and the aperture of the second circular hole 115 is larger than the aperture of the connecting hole 124; a sealing connection is arranged between the plugging head 109 and the external body;

[0039] The external body 107 is provided with a suction hole 116 , the suction catheter 108 is installed on the external body 107 and communicated with the suction hole 116 , and the end of the plugging head 109 and the first tapered hole 111 form a negative pressure chamber 117 .

[0040] The first placement groove 102 is used to connect with the plugging head 109, the second placement groove 103 is used to connect with the suction catheter 108, a first heating device 104 is arranged between the first placement groove 102 and the plugging head 109, the delivery pump 101 is arranged between the first placement groove 102 and the first heating device 104, and the jet pump 105 is connected with a separator 125.

[0041] In actual use, the present invention realizes full mixing of defluorinated acid and hydrogen peroxide by means of the provided Venturi jet pump 105. The high-temperature defluorinated acid is delivered to the inlet of the Venturi jet pump 105 by the delivery pump 101. After the high-speed acid passes through the diameter change of the Venturi tube, the flow velocity increases sharply and the pressure decreases. A vacuum is formed at the rear of the acid mist cone sprayed from the nozzle. External hydrogen peroxide is continuously sucked into the suction conduit 108 from the hydrogen peroxide inlet. The newly sucked hydrogen peroxide collides and mixes with the acid mist cone in the negative pressure chamber 117 and is sprayed out from the spray port along with the acid mist, thereby achieving full mixing of the defluorinated acid and hydrogen peroxide. Compared with the existing microreactor, the present invention has fewer sealing points, effectively avoids safety and environmental accidents caused by leakage due to redox reaction in a high-temperature environment, and improves the safety of use.

[0042] At the same time, the separator 125 is provided to achieve rapid separation of the bleaching acid.

[0043] In actual use, the flow volume ratio of defluorinated acid to hydrogen peroxide is 30: 1. To ensure that the defluorinated acid and hydrogen peroxide are fully mixed, the separator 125 is a centrifugal separator 125 .

[0044] Among them, the concentration of hydrogen peroxide is 27%-28%.

[0045] In some preferred embodiments, the plugging head 109 and the mounting hole 110 are connected via threads.

[0046] Furthermore, the mounting hole 110 is a stepped hole.

[0047] The end of the plugging head 109 near the first conical surface is provided with an inclined surface 118. The inclined surface 118 can form a drainage effect inside the negative pressure chamber 117, so that the hydrogen peroxide can flow through the inclined surface 118 under the action of negative pressure and be fully mixed with the defluorinated acid.

[0048] In this embodiment, the aperture of the second circular hole 115 is larger than the aperture of the connecting hole 124, so that the overall structure can achieve secondary acceleration. First, acceleration is achieved at the second circular hole 115, so that the defluorinated acid can enter the negative pressure chamber 117 at a high speed, and then when flowing through the connecting hole 124, the mixed material is accelerated again, so that the defluorinated acid and hydrogen peroxide are mixed for the first time inside the negative pressure chamber 117, and secondary mixing is achieved in the second conical hole 112, thereby improving the mixing effect.

[0049] In actual use, connecting flanges are provided on both sides of the outer body 107 .

[0050] In actual use, in order to achieve the mixing effect of defluorinated acid and hydrogen peroxide in the Venturi jet pump 105, this embodiment also discloses another structure of the Venturi jet pump 105; the structure of the Venturi jet pump 105 is further optimized in the structure of the Venturi jet pump 105 described above, and the structure can be replaced according to the production line capacity requirements;

[0051] The plugging head 109 includes a first plugging head 119 and a second plugging head 120, the first plugging head 119 and the second plugging head 120 are connected by threads, the first round hole 113 is provided on the first plugging head 119, the second round hole 115 and the third tapered hole 114 are provided on the second plugging head 120, and the first plugging head 119 and the second plugging head 120 are connected and then installed on the external body 107;

[0052] Among them, a first mounting hole 121 is provided on the external body 107, the first mounting hole 121 is connected to the first conical hole 111, a replacement head 122 is provided in the first mounting hole 121, a connecting hole 124 and a second conical hole 112 are provided on the replacement head 122, and a first conical auxiliary hole 123 with the same taper as the first conical hole 111 is provided on the replacement head 122.

[0053] In this way, in actual use, the plugging head 109 and the replacement head 122 can be replaced to change the mixing effect of the defluorinated acid and the hydrogen peroxide in the Venturi jet pump 105 .

[0054] In the present embodiment, the aperture ratio of the first circular hole 113 to the second circular hole 115 determines the flow rate and pressure entering the negative pressure chamber 117. At the same time, since the aperture of the second circular hole 115 is larger than the aperture of the connecting hole 124, the defluorinated acid and the hydrogen peroxide solution can be mixed once in the negative pressure chamber 117 and mixed twice in the second conical hole 112. At the same time, by replacing the plugging head 109 and the replacement head 122 of different specifications, the mixing effect can also be adjusted, which can meet the use of different working conditions and greatly improve the use range of the device.

[0055] Furthermore, in actual use, the plugging head 109, the outer body 107, and the replacement head 122 are all made of graphite material, which can effectively avoid high-temperature phosphoric acid corrosion of the equipment and effectively reduce quality accidents. At the same time, compared with the stainless steel micro-reactor in the prior art, the present application is not prone to corrosion in actual use, which can effectively reduce the amount of maintenance work.

[0056] Furthermore, as an optional embodiment, in actual use, the surfaces of the first circular hole 113, the third conical hole 114, the second circular hole 115, the mounting hole 110, the first conical hole 111, the first conical auxiliary hole 123, the connecting hole 124 and the second conical hole 112 are all provided with a graphite layer, which can effectively reduce costs compared to using all graphite materials.

[0057] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Venturi jet pump structure, comprising a bracket, characterized in that: It also includes an external body, a suction catheter and a plugging head. The external body is used to be fixedly mounted on the bracket. The left side of the external body is provided with a mounting hole, and the right side is provided with a first tapered hole and a second tapered hole. The large end of the first tapered hole is connected to the mounting hole, and the small end of the second tapered hole is connected to the first tapered hole through the connecting hole. The plugging head is installed in the installation hole, and a first circular hole, a third conical hole and a second circular hole are sequentially arranged inside the plugging head; a sealing connection is arranged between the plugging head and the external body; Wherein, a suction hole is arranged on the external body, a suction catheter is installed on the external body and communicated with the suction hole, and the end of the sealing head and the first conical hole form a negative pressure chamber.

2. A Venturi jet pump structure according to claim 1, characterized in that: The plugging head is connected to the mounting hole through threads.

3. A Venturi jet pump structure according to claim 1, characterized in that: The mounting holes are stepped holes.

4. A Venturi jet pump structure according to claim 1, characterized in that: A slope is arranged on one side of the plugging head end close to the first conical surface.

5. A Venturi jet pump structure according to claim 1, characterized in that: Connecting flanges are arranged on both sides of the external body.

6. A bleaching method, characterized in that: The method comprises adopting the following system for bleaching, the system comprising a delivery pump, a first placement tank, a second placement tank, a first heating device and a jet pump, the first placement tank is used to place defluorinated acid, the second placement tank is used to place hydrogen peroxide, and the jet pump is a Venturi jet pump structure as described in any one of claims 1 to 5; The first placement groove is used to connect with the plugging head, the second placement groove is used to connect with the suction catheter, a first heating device is arranged between the first placement groove and the plugging head, the delivery pump is arranged between the first placement groove and the first heating device, and the jet pump is connected with a separator.

7. A bleaching method according to claim 6, characterized in that: The separator is a centrifugal separator.

8. A bleaching method according to claim 1, characterized in that: The concentration of hydrogen peroxide is 27%-28%.

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