Preparation device of flaky disodium hydrogen phosphate dihydrate

Abstract

The utility model provides a preparation device of flaky disodium hydrogen phosphate dihydrate. The preparation device comprises a disodium hydrogen phosphate dodecahydrate melting kettle and a flash chamber which are communicated with each other, the flash chamber is provided with a liquid outlet pipe and a liquid return pipe, and the liquid outlet pipe and the liquid return pipe are communicated with the heat exchanger; the liquid outlet pipe is provided with a first three-way pipe which is communicated with the disodium hydrogen phosphate dodecahydrate melting kettle, and is provided with a second three-way pipe which is communicated with the disodium hydrogen phosphate dihydrate melting kettle; and the disodium hydrogen phosphate dihydrate melting kettle is communicated with a flaker to flake molten disodium hydrogen phosphate dihydrate. The sodium hydrogen phosphate dihydrate production device has the beneficial effects that the prepared sodium hydrogen phosphate dihydrate product is in a sheet shape, and the product in the sheet shape is not easy to generate dust in the transportation process, so that environmental pollution and health risks are reduced. Due to the structural characteristics of the sheet-shaped product, the sheet-shaped product is not prone to hardening, good fluidity can be kept even in the long-time storage and transportation process, and therefore material loss and treatment cost caused by hardening are greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of a preparation device for disodium hydrogen phosphate dihydrate, in particular to a preparation device for flaky disodium hydrogen phosphate dihydrate. Background Art

[0002] Disodium hydrogen phosphate dodecahydrate is a byproduct of the glyphosate industry. However, due to its low melting point and difficulty in transportation, the industry often converts it into disodium hydrogen phosphate dihydrate. Currently, disodium hydrogen phosphate dihydrate is primarily produced by evaporation and concentration followed by centrifugation. Concentration equipment typically uses single-effect, multi-effect, or MVR devices. After thickening, the evaporation concentrate is centrifuged to separate the disodium hydrogen phosphate dihydrate.

[0003] In the glyphosate industry, the moisture content of sodium phosphate dihydrate (DPHD) discharged from centrifuges is typically between 4% and 5%. This relatively high moisture content causes the material to easily harden and clump upon cooling to room temperature, forming hard lumps. This phenomenon not only significantly affects the material's fluidity but also presents numerous challenges to continuous production. Hardened material is difficult to handle and transport, limiting production continuity and efficiency while also increasing the cost and complexity of storage and transportation. Furthermore, hardened material may further deteriorate during storage due to moisture absorption, leading to a decrease in quality and compromising its performance and stability in subsequent applications. To address this issue, the industry urgently needs to implement effective measures to ensure the smooth production and use of DPHD. Furthermore, to ensure that qualified DPHD is obtained, some concentrated liquid is discharged after evaporation and concentration to a certain extent, which is costly to dispose of as hazardous waste. Utility Model Content

[0004] Aiming at the shortcomings of existing technologies, the present invention aims to solve the problem that the relatively high water content of disodium hydrogen phosphate dihydrate causes the material to easily form lumps when cooled to room temperature, and to solve the problem that the concentrated solution is expensive to be disposed of as hazardous waste.

[0005] The utility model provides a preparation device of flaky disodium hydrogen phosphate dihydrate, comprising a disodium hydrogen phosphate dodecahydrate melting kettle and a flash chamber which are connected to each other; a heat exchanger, a disodium hydrogen phosphate dihydrate melting kettle and a flake forming machine, wherein the flash chamber is provided with a liquid outlet pipe and a liquid return pipe which are connected to the heat exchanger; the liquid outlet pipe is provided with a first three-way pipe which is connected to the disodium hydrogen phosphate dodecahydrate melting kettle, and the liquid outlet pipe is provided with a second three-way pipe which is connected to the disodium hydrogen phosphate dihydrate melting kettle; the disodium hydrogen phosphate dihydrate melting kettle is connected to the flake forming machine to form molten disodium hydrogen phosphate dihydrate into flakes.

[0006] As a preferred solution, a proportional valve is provided on the pipeline connecting the second three-way pipe to the disodium hydrogen phosphate dihydrate melting kettle.

[0007] As a preferred solution, a feed pump is provided between the disodium hydrogen phosphate dodecahydrate melting kettle and the first tee pipe; a circulation pump is provided between the first tee pipe and the second tee pipe; and a flaker feed pump is provided between the disodium hydrogen phosphate dihydrate melting kettle and the flaker.

[0008] As a preferred solution, a gas outlet pipe is provided on the top of the flash chamber to connect to a heat exchanger to recover gas phase heat, and a steam compressor is provided on the gas outlet pipe.

[0009] As a preferred solution, the heat exchanger is connected to a first condenser for cooling the gas phase, and the first condenser is connected to a condensation water tank for collecting condensate.

[0010] As a preferred solution, the disodium hydrogen phosphate dihydrate melting kettle is provided with a second condenser to cool the exhaust gas.

[0011] As a preferred solution, the condensed water tank, the second condenser and the flaker are provided with outlet pipes connected to an absorption tower for absorbing tail gas.

[0012] As a preferred solution, a water ring vacuum pump is provided between the condensed water tank and the absorption tower; the absorption tower is provided with an absorption tower spray pump and a circulation pipeline is provided to connect with the absorption tower spray pump.

[0013] As a preferred solution, the heat exchanger and the condensed water tank are connected to a water ring vacuum pump for evacuation before use.

[0014] The beneficial effects of the utility model are:

[0015] 1. The disodium hydrogen phosphate dihydrate product prepared by the present invention is in a flake form. This form of product is less likely to generate dust during transportation, reducing environmental pollution and health risks. Due to its structural characteristics, the flake product is less likely to become hardened and can maintain good fluidity even during long-term storage and transportation, which greatly reduces material loss and processing costs caused by hardening.

[0016] 2. The present invention does not generate mother liquor waste, which means that there is no need to discharge mother liquor. In traditional production processes, the discharge of mother liquor is often accompanied by environmental pollution and hazardous waste disposal issues. The present invention achieves internal recycling of mother liquor, which not only reduces environmental pollution but also lowers the cost and risk of hazardous waste disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the utility model easier to understand, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 This is a structural diagram of Example 1.

[0019] Figure 2 This is a schematic structural diagram of Example 2.

[0020] The reference numerals in the accompanying drawings are:

[0021] 1. Disodium hydrogen phosphate dodecahydrate melting kettle; 2. Feed pump; 3. Flash chamber; 31. Liquid outlet pipe; 32. Liquid return pipe; 33. Gas phase outlet pipe; 4. Steam compressor; 5. Heat exchanger; 6. Circulating pump; 7. Condenser A; 8. Condenser B; 9. Disodium hydrogen phosphate dihydrate melting kettle; 10. Flaking machine feed pump; 11. Condensate tank; 12. Water ring vacuum pump; 13. Flaking machine; 14. Absorption tower; 15. Absorption tower spray pump; 16. First tee pipe; 17. Second tee pipe; 18. Proportional valve. DETAILED DESCRIPTION

[0022] To illustrate the features of the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Example 1:

[0024] refer to Figure 1 This embodiment provides a device for preparing flaky disodium phosphate dihydrate, comprising a disodium phosphate dihydrate melting kettle 1 and a flash chamber 3, interconnected therewith; a heat exchanger 5, a disodium phosphate dihydrate melting kettle 9, and a flake forming machine 13. The flash chamber 3 is provided with a liquid outlet pipe 31 and a liquid return pipe 32, which are connected to the heat exchanger 5. The liquid outlet pipe 31 is provided with a first tee pipe 16, which is connected to the disodium phosphate dihydrate melting kettle 1; the liquid outlet pipe 31 is provided with a second tee pipe 17, which is connected to the disodium phosphate dihydrate melting kettle 9; and the disodium phosphate dihydrate melting kettle 9 is connected to the flake forming machine 13, which forms the molten disodium phosphate dihydrate into flakes. By arranging the disodium phosphate dihydrate melting kettle 9 and the flake forming machine 13 after the flash chamber 3, the disodium phosphate dihydrate product is processed into a flake form. This form of product is less likely to generate dust during transportation, reducing environmental pollution and health risks. Due to their structural characteristics, sheet products are not prone to compaction and can maintain good fluidity even during long-term storage and transportation, which greatly reduces material loss and processing costs caused by compaction.

[0025] In this embodiment, a proportional valve 18 is further provided on the pipeline connecting the second three-way pipe 17 to the disodium hydrogen phosphate dihydrate melting kettle 9, and the ratio of the liquid phase entering the disodium hydrogen phosphate dihydrate melting kettle 9 is set to 1:300, so as to prevent the liquid phase from entering the disodium hydrogen phosphate dihydrate melting kettle 9 too quickly, so that the disodium hydrogen phosphate dihydrate in the liquid phase is fully separated from the water vapor in the flash chamber 3.

[0026] In addition, in order to ensure the overall operating efficiency of the system, in this embodiment, a feed pump 2 is provided between the disodium hydrogen phosphate dodecahydrate melting kettle 1 and the first tee pipe 16; a circulation pump 6 is provided between the first tee pipe 16 and the second tee pipe 17; a flaker feed pump 10 is provided between the disodium hydrogen phosphate dihydrate melting kettle 9 and the flaker 13, and the outlet of the flaker feed pump 10 is connected to the feed port of the flaker 13. The material conveying device is a conveyor belt, and a distributor is provided at the feed port of the flaker. The molten disodium hydrogen phosphate dodecahydrate is evenly spread on the conveyor belt through the distributor, and the appropriate distribution speed and conveyor belt speed are set so that the molten material is spread on the conveyor belt to form a liquid film with a thickness of about 0.5~1.5mm. A baffle is installed inside the flaker, dividing the flaker into two sections. The front section is the hot air section, which is used to remove excess free water. The rear section is the cold air section, which is used to cool and solidify disodium hydrogen phosphate dihydrate. The lengths of the hot air section and the cold air section can be freely set according to the moisture required to be removed from the material. The baffle is close to the conveyor belt, and the distance between the baffle and the conveyor belt can be freely adjusted, generally 2~5mm.

[0027] Example 2:

[0028] refer to Figure 2 This embodiment, based on Example 1, provides an improved apparatus for preparing disodium hydrogen phosphate dihydrate in flake form. The apparatus comprises a disodium hydrogen phosphate dodecahydrate melting kettle 1 and a flash chamber 3, interconnected therewith; a heat exchanger 5, a disodium hydrogen phosphate dihydrate melting kettle 9, and a flake forming machine 13. The flash chamber 3 is provided with a liquid outlet pipe 31 and a liquid return pipe 32, connecting to the heat exchanger 5. The liquid outlet pipe 31 is provided with a first tee pipe 16, connecting to the disodium hydrogen phosphate dodecahydrate melting kettle 1, and a second tee pipe 17, connecting to the disodium hydrogen phosphate dihydrate melting kettle 9. The disodium hydrogen phosphate dihydrate melting kettle 9 is connected to the flake forming machine 13, which forms the molten disodium hydrogen phosphate dihydrate into flakes. By providing the disodium hydrogen phosphate dihydrate melting kettle 9 and the flake forming machine 13 after the flash chamber 3, the disodium hydrogen phosphate dihydrate product is processed into a flake form. This form of product is less likely to generate dust during transportation, reducing environmental pollution and health risks. Due to their structural characteristics, sheet products are not prone to compaction and can maintain good fluidity even during long-term storage and transportation, which greatly reduces material loss and processing costs caused by compaction.

[0029] In this embodiment, a proportional valve 18 is further provided on the pipeline connecting the second three-way pipe 17 to the disodium hydrogen phosphate dihydrate melting kettle 9, and the ratio of the liquid phase entering the disodium hydrogen phosphate dihydrate melting kettle 9 is set to 1:400 to prevent the liquid phase from entering the disodium hydrogen phosphate dihydrate melting kettle 9 too quickly, so that the disodium hydrogen phosphate dihydrate in the liquid phase is fully separated from the water vapor in the flash chamber 3.

[0030] In addition, in order to ensure the overall operating efficiency of the system, in this embodiment, a feed pump 2 is provided between the disodium hydrogen phosphate dodecahydrate melting kettle 1 and the first tee pipe 16; a circulation pump 6 is provided between the first tee pipe 16 and the second tee pipe 17; a flaker feed pump 10 is provided between the disodium hydrogen phosphate dihydrate melting kettle 9 and the flaker 13, and the outlet of the flaker feed pump 10 is connected to the feed port of the flaker 13. The material conveying device is a conveyor belt, and a distributor is provided at the feed port of the flaker. The molten disodium hydrogen phosphate dodecahydrate is evenly spread on the conveyor belt through the distributor, and the appropriate distribution speed and conveyor belt speed are set so that the molten material is spread on the conveyor belt to form a liquid film with a thickness of about 0.5~1.5mm. A baffle is installed inside the flaker, dividing the flaker into two sections. The front section is the hot air section, which is used to remove excess free water. The rear section is the cold air section, which is used to cool and solidify disodium hydrogen phosphate dihydrate. The lengths of the hot air section and the cold air section can be freely set according to the moisture required to be removed from the material. The baffle is close to the conveyor belt, and the distance between the baffle and the conveyor belt can be freely adjusted, generally 2~5mm.

[0031] Unlike Example 1, this embodiment integrates a waste liquid and waste gas recovery system in addition to the flaking system. First, to recycle the waste heat from the flash chamber 3, a gas outlet pipe 33 is installed at the top of the flash chamber 3, connecting to a heat exchanger 5 to recover gas phase heat. The heat exchanger 5 uses the gas phase heat to further heat the liquid phase. To ensure operational efficiency, a steam compressor 4 is installed in this embodiment on the gas outlet pipe 33. The gas outlet pipe corresponding to the gas outlet pipe 33 of the heat exchanger 5 is connected to the first condenser 7, which cools the gas phase. The first condenser 7 is connected to the condensate tank 11, which collects the condensate. The condensate is cooled by the first condenser 7 and then collected in the condensate tank 11.

[0032] In addition, a second condenser 8 is provided in the disodium hydrogen phosphate dihydrate melting kettle 9 to cool the exhaust gas. The condensed water tank 11, the second condenser 8, and the flaker 13 are processed uniformly. An outlet pipe is provided to connect to an absorption tower 14 for absorbing the exhaust gas. Two gas phase outlets are provided at the top of the flaker, one for discharging hot and humid air and the other for discharging cold and dry air. The exhaust gas from the flaker enters the absorption tower 14 for processing, fully ensuring the operating efficiency of the pipelines within the system. In this embodiment, a water ring vacuum pump 12 is provided between the condensed water tank 11 and the absorption tower 14; the absorption tower 14 is provided with an absorption tower spray pump 15, and a circulation pipe is provided to connect to the absorption tower spray pump 15 to improve the reaction efficiency.

[0033] In particular, in order to evacuate the condensed water tank 11 and the absorption tower 14 before the system is operated, in this embodiment, the heat exchanger 5 and the condensed water tank 11 are connected to a water ring vacuum pump 12.

[0034] The above embodiments and accompanying drawings are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions, or substitutions made by those skilled in the art within the spirit of the present invention do not depart from the spirit of the present invention and are intended to fall within the scope of the claims of the present invention. Other related technical structures not fully disclosed in this utility model are prior art in the art.

Claims

1. A device for preparing flaky disodium hydrogen phosphate dihydrate, comprising a disodium hydrogen phosphate dodecahydrate melting kettle (1) and a flash chamber (3) which are interconnected; Its characteristics are: It also includes a heat exchanger (5), a disodium hydrogen phosphate dihydrate melting kettle (9) and a flaker (13), and the flash chamber (3) is provided with a liquid outlet pipe (31) and a liquid return pipe (32) connected to the heat exchanger (5); The liquid outlet pipe (31) is provided with a first three-way pipe (16) to be connected to the disodium hydrogen phosphate dodecahydrate melting kettle (1), and the liquid outlet pipe (31) is provided with a second three-way pipe (17) to be connected to the disodium hydrogen phosphate dihydrate melting kettle (9); The disodium hydrogen phosphate dihydrate melting kettle (9) is connected to the flake forming machine (13) to form the molten disodium hydrogen phosphate dihydrate into flakes.

2. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 1, wherein: A proportional valve (18) is provided on the pipeline connecting the second three-way pipe (17) to the disodium hydrogen phosphate dihydrate melting kettle (9). The proportional valve (18) controls the ratio of the liquid phase entering the disodium hydrogen phosphate dihydrate melting kettle (9) to the total flow of the pipeline to be 1:400 to 1:

300.

3. The preparation device of the sheet-like disodium hydrogen phosphate dihydrate according to claim 2, characterized in that: A feed pump (2) is provided between the disodium hydrogen phosphate dodecahydrate melting kettle (1) and the first three-way pipe (16); a circulation pump (6) is provided between the first three-way pipe (16) and the second three-way pipe (17); and a flaker feed pump (10) is provided between the disodium hydrogen phosphate dihydrate melting kettle (9) and the flaker (13).

4. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 1, wherein: A gas outlet pipe (33) is provided on the top of the flash chamber (3) and is connected to a heat exchanger (5) for recovering gas phase heat. A steam compressor (4) is provided on the gas outlet pipe (33).

5. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 4, wherein: The heat exchanger (5) is connected to a first condenser (7) for cooling the gas phase, and the first condenser (7) is connected to a condensation water tank (11) for collecting condensate.

6. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 5, wherein: The disodium hydrogen phosphate dihydrate melting kettle (9) is provided with a second condenser (8) to cool the exhaust gas.

7. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 6, wherein: The condensed water tank (11), the second condenser (8), and the flaker (13) are provided with outlet pipes connected to an absorption tower (14) for absorbing tail gas.

8. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 7, wherein: A water ring vacuum pump (12) is provided between the condensed water tank (11) and the absorption tower (14); an absorption tower spray pump (15) is provided on the absorption tower (14), and a circulation pipeline is provided to communicate with the absorption tower spray pump (15).

9. The device for preparing flaky disodium hydrogen phosphate dihydrate according to claim 8, wherein: The heat exchanger (5) and the condensed water tank (11) are connected to a water ring vacuum pump (12) for evacuation before use.

Images