Phosphoric acid solution feeding system

Abstract

The application provides a phosphoric acid solution feeding system applied to a lithium iron phosphate positive material production line, which comprises a storage unit for storing the phosphoric acid solution, a metering unit and a control unit, the storage unit is communicated with the metering unit through a pipeline, the metering unit comprises a detection bin and a metering bin, the detection bin is used for detecting the concentration of phosphoric acid in the flowing phosphoric acid solution, the control unit can calculate the required phosphoric acid solution feeding amount according to the detected concentration of phosphoric acid, and the phosphoric acid solution in the storage unit can flow into the metering bin according to the phosphoric acid solution feeding amount, and the metering bin can detect the weight of the phosphoric acid solution entering it. According to the phosphoric acid solution feeding system, the concentration of phosphoric acid is detected through the detection bin, so that the phosphoric acid solution feeding amount can be accurately calculated. And the metering bin is arranged, the measurement accuracy of the phosphoric acid solution feeding amount is improved, so that the production of lithium iron phosphate positive material is not affected by the imbalance of material ratio.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium iron phosphate cathode material preparation, in particular to a phosphoric acid solution feeding system. BACKGROUND

[0002] Phosphoric acid is an important raw material for preparing lithium iron phosphate cathode material. Before feeding, the concentration of phosphoric acid solution is tested, and the amount of phosphoric acid solution is calculated according to the concentration of phosphoric acid. Phosphoric acid is a medium-strong acid, and its crystallization point (freezing point) is 21℃. When the temperature is lower than this temperature, semi-water crystals (ice) will be precipitated, which may result in the following results: the upper and lower layers of the phosphoric acid solution have different concentrations after the phosphoric acid is frozen, which leads to a large difference between the actual concentration and the expected concentration when calculating the amount of phosphoric acid solution, resulting in too much or too little phosphoric acid solution, and ultimately affecting the lithium iron ratio and other indicators of the finished lithium iron phosphate cathode material. SUMMARY

[0003] In view of the above, the present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a phosphoric acid solution feeding system, which has the advantages of convenient storage of phosphoric acid solution, accurate metering and safe feeding.

[0004] The present application provides a phosphoric acid solution feeding system, which is applied to a lithium iron phosphate cathode material production line, and includes a storage unit for storing phosphoric acid solution, a metering unit and a control unit. The storage unit and the metering unit are connected through a pipeline. The metering unit includes a detection bin and a metering bin. The detection bin is used to detect the concentration of phosphoric acid in the flowing phosphoric acid solution. The control unit can calculate the required amount of phosphoric acid solution according to the detected concentration of phosphoric acid, and control the flow of phosphoric acid solution in the storage unit into the metering bin according to the amount of phosphoric acid solution. The metering bin can detect the weight of the phosphoric acid solution entering it.

[0005] In some embodiments, the storage unit includes a storage tank for storing phosphoric acid solution and a water pipe. The storage tank includes an outer wall and an inner wall, and a hollow jacket layer is arranged between the outer wall and the inner wall. The water pipe is accommodated in the jacket layer.

[0006] In some embodiments, the water pipe is wound on the outer side of the inner wall in a spiral manner. Hot water is contained in the water pipe to keep the phosphoric acid solution in the storage tank warm.

[0007] In some embodiments, the lithium iron phosphate anode material production line comprises a kiln and a kiln cooling area, the kiln cooling area containing cooling water for absorbing heat from the kiln, the water inlet of the water pipe being connected to the kiln cooling area, and the cooling water in the kiln cooling area that has absorbed heat from the kiln being introduced into the water pipe to transfer heat to the phosphoric acid solution in the storage tank, thereby keeping the phosphoric acid solution warm.

[0008] In some embodiments, the detection chamber is provided with at least one concentration detection device, which sends the detected concentration of phosphoric acid to the control unit, and the control unit calculates the required amount of phosphoric acid solution based on the detected concentration of phosphoric acid.

[0009] In some embodiments, the third valve and the fourth valve are respectively arranged at the outlet of the detection chamber, when the concentration of phosphoric acid detected by the concentration detection device meets the requirements, the control unit controls the third valve to be closed and the fourth valve to be opened, so that the phosphoric acid solution enters the metering chamber; when the concentration of phosphoric acid detected by the concentration detection device does not meet the requirements, the control unit controls the third valve to be opened and the fourth valve to be closed, so that the phosphoric acid solution does not enter the metering chamber.

[0010] In some embodiments, the phosphoric acid solution feeding system is provided with a flow meter at the fourth valve, which counts the flow of phosphoric acid solution flowing through the fourth valve in real time and sends a signal to the control unit when the feeding amount of phosphoric acid solution is reached, and the control unit controls the fourth valve to be closed, so that the phosphoric acid solution stops flowing into the metering chamber.

[0011] In some embodiments, the metering chamber is provided with a weighing device for measuring the weight of the phosphoric acid solution flowing into the metering chamber, and when the weight of the phosphoric acid solution flowing into the metering chamber reaches the feeding amount calculated by the control unit, the metering chamber sends a signal to the control unit, and the control unit controls the phosphoric acid solution to stop flowing into the metering chamber.

[0012] In some embodiments, the phosphoric acid solution feeding system further comprises a feeding unit, which is in communication with the metering unit through a pipeline, and the feeding unit is provided with a weighing device for measuring the weight of the phosphoric acid solution flowing into the feeding unit.

[0013] In some embodiments, the storage unit, the metering unit, the feeding unit and the pipeline are coated with an anti-corrosion layer at the parts in contact with the phosphoric acid solution.

[0014] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. Attached Figure Description

[0015] Figure 1 This is a control system block diagram of the phosphoric acid solution feeding system according to an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the phosphoric acid solution feeding system according to an embodiment of the present invention.

[0017] Figure label:

[0018] Phosphoric acid solution feeding system 100;

[0019] Kiln 10; Kiln cooling zone 15; Premix tank 20;

[0020] Storage unit 30; storage tank 31; outer wall 311; inner wall 312; jacket layer 313; water pipe 32;

[0021] Metering unit 40; Detection chamber 41; Metering chamber 42;

[0022] Feeding unit 50; Pipeline 60;

[0023] First valve 71; Second valve 72; Third valve 74; Fifth valve 75; Sixth valve 76;

[0024] Control unit 80. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0027] This invention provides a phosphoric acid solution feeding system 100. The phosphoric acid solution feeding system 100 according to an embodiment of the invention is described below with reference to the accompanying drawings.

[0028] The phosphoric acid solution feeding system 100 can be applied to a lithium iron phosphate cathode material production line to prepare lithium iron phosphate cathode material. Please refer to Figure 2 The lithium iron phosphate cathode material production line can include the phosphoric acid solution feeding system 100, a kiln 10 for calcining material, and a premixing tank 20 for mixing material. A kiln cooling area 15 is arranged outside the kiln 10 and contains cooling water therein, which can absorb heat generated by the kiln 10 to cool the kiln 10.

[0029] Please refer to Figure 1 and Figure 2 The phosphoric acid solution feeding system 100 includes a storage unit 30, a metering unit 40, a feeding unit 50, a pipeline 60, and a control unit 80. The pipeline 60 is used to connect the storage unit 30, the metering unit 40, and the feeding unit 50, and the control unit 80 can control the operation of the storage unit 30, the metering unit 40, the feeding unit 50, and the pipeline 60.

[0030] The storage unit 30 includes a storage tank 31 for storing phosphoric acid solution and a water pipe 32 for heat preservation of the phosphoric acid solution. The storage tank 31 includes an outer wall 311 and an inner wall 312, and a hollow jacket layer 313 is arranged between the outer wall 311 and the inner wall 312. The water pipe 32 can be accommodated in the jacket layer 313, and the water pipe 32 is filled with hot water inside, thereby achieving the heat preservation function of the phosphoric acid solution. In an embodiment, the water pipe 32 can be wound outside the inner wall 312 in a spiral manner to more fully contact the inner wall 312, thereby more conveniently heat preserving the phosphoric acid solution. It can be understood that, in order to ensure the heat preservation effect, the hot water is preferably water with a temperature of 40°C or higher.

[0031] In the embodiment of the present application, the water inlet and the water outlet of the water pipe 32 are connected with the kiln cooling area 15, wherein a first valve 71 and a turbine pump (not shown in the figure) are arranged at the water inlet. When the first valve 71 is opened, the control unit 80 can control the turbine pump to operate to drive the cooling water in the kiln cooling area 15, which absorbs heat generated by the kiln 10, to enter the water pipe 32. When the cooling water flows through the water pipe 32 wound outside the storage tank 31, it transfers heat to the phosphoric acid solution in the storage tank 31 and then returns to the kiln cooling area 15 from the water outlet of the water pipe 32 to cool the kiln 10 again and absorb heat generated by the kiln 10.

[0032] The phosphoric acid solution feeding system 100 of the present application can heat the phosphoric acid solution in the storage tank 31 by using the heat of the cooling water flowing out of the storage tank 31, which has absorbed the heat of the kiln 10. On the one hand, the energy utilization efficiency of the lithium iron phosphate positive electrode material production line can be improved, and the heat loss can be reduced. On the other hand, the problem of unbalanced feeding caused by the crystallization of the phosphoric acid solution can be prevented, and the production cost can be reduced.

[0033] It can be understood that, in order to better control the temperature of the phosphoric acid solution in the storage tank 31, a thermometer for measuring the temperature of the phosphoric acid solution can be arranged in the storage tank 31. When the thermometer detects that the temperature of the phosphoric acid solution is low, the control unit 80 can increase the power of the turbine pump and accelerate the flow rate of the cooling water to provide more heat to the phosphoric acid solution; when it is detected that the temperature of the phosphoric acid solution is high, the control unit 80 can reduce the power of the turbine pump and reduce the flow rate of the cooling water to reduce the heat so as to reduce the temperature of the phosphoric acid solution. In this way, the temperature of the phosphoric acid solution can be ensured to be maintained within a suitable temperature range.

[0034] Please continue to refer to FIG. 2, the metering unit 40 is connected with the storage unit 30 through the pipeline 60, and the metering unit 40 comprises a detection bin 41 and a metering bin 42. The storage tank 31 is provided with a second valve 72 and a turbine pump (not shown in the figure) at the connection position of the storage tank 31 and the pipeline 60. When the second valve 72 is opened, the control unit 80 can control the turbine pump to operate to drive the phosphoric acid solution in the storage tank 31 to flow into the detection bin 41 and the metering bin 42 in sequence. In the embodiment of the present application, the detection bin 41 is respectively provided with a third valve 73 and a fourth valve 74 at the outlet of the detection bin 41, and a concentration detection device (not shown in the figure) is arranged in the detection bin 41. When the phosphoric acid solution flows into the detection bin 41 through the second valve 72, the third valve 73 and the fourth valve 74 are closed. The concentration detection device detects the concentration of the phosphoric acid and sends the detected data to the control unit 80. When the concentration of the phosphoric acid meets the requirements, the control unit 80 calculates the required feeding amount of the phosphoric acid solution according to the concentration of the phosphoric acid and the material ratio. At this time, the control unit 80 controls the third valve 73 to be closed and the fourth valve 74 to be opened, so that the phosphoric acid solution enters the metering bin 42. When the concentration of the phosphoric acid does not meet the requirements, the control unit 80 controls the third valve 73 to be opened and the second valve 72 and the fourth valve 74 to be closed, so that the phosphoric acid solution flows into a recovery bin (not shown in the figure).

[0035] To make the measurement of the concentration of phosphoric acid more accurate, in an embodiment, two concentration measuring devices can be arranged above and below the detection chamber 41. When the phosphoric acid solution flows into the detection chamber 41, the two concentration measuring devices measure the concentration of phosphoric acid respectively and send the measured data of the concentration of phosphoric acid to the control unit 80. The control unit 80 processes the two data of the concentration of phosphoric acid, and if both of them meet the requirements, the average value is calculated to determine the amount of the phosphoric acid solution to be fed. If any one of the data of the concentration of phosphoric acid does not meet the requirements, the phosphoric acid solution in the detection chamber 41 is fed back to the recovery chamber.

[0036] The weighing device is arranged in the metering chamber 42. When the weight of the phosphoric acid solution flowing into the metering chamber 42 through the detection chamber 41 and the fourth valve 74 reaches the required amount to be fed, the metering chamber sends a signal to the control unit 80, and the control unit 80 controls the fourth valve 74 to be closed. At this time, the metering of the amount of the phosphoric acid solution to be fed is completed.

[0037] It can be understood that when the control unit 80 controls the fourth valve 74 to be closed, there is still phosphoric acid solution in the pipeline 60 between the fourth valve 74 and the metering chamber 42 which has not entered the metering chamber 42. In order to make the metering of the phosphoric acid solution entering the metering chamber 42 more accurate, in an embodiment of the present application, the fourth valve 74 can be arranged at the entrance of the metering chamber 42, so as to reduce the residual phosphoric acid solution between the fourth valve 74 and the metering chamber 42.

[0038] In another embodiment of the present application, a flow meter can also be arranged at the fourth valve 74. The flow meter can be used to count the flow of the phosphoric acid solution flowing through the fourth valve 74 in real time, and send a signal to the control unit 80 when the amount of the phosphoric acid solution to be fed is reached, so that the control unit 80 controls the fourth valve 74 to be closed. At this time, the control unit 80 can compare whether the amount of the phosphoric acid solution to be fed counted by the flow meter and the amount of the phosphoric acid solution to be fed detected by the weighing device are within the allowable error range. If they are within the allowable error range, the metering of the amount of the phosphoric acid solution to be fed is completed. If they are not within the allowable error range, the control unit 80 sends a pre-warning information.

[0039] The phosphoric acid solution feeding system 100 of the present application can accurately measure the concentration of the phosphoric acid solution by arranging the detection chamber 41, so as to facilitate the control unit 80 to accurately calculate the required amount of the phosphoric acid solution to be fed. The metering chamber 42 can accurately measure whether the fed phosphoric acid solution meets the required amount to be fed. Therefore, the present application can realize automatic detection of the concentration of phosphoric acid and automatic calculation of the amount to be fed, and improve the production efficiency and the metering accuracy.

[0040] Please continue to refer to Figure 2The feeding unit 50 is connected with the metering bin 42 through a pipeline 60, and the bottom of the metering bin 42 is provided with a fifth valve 75 and a turbine pump (not shown in the figure). When the fifth valve 75 is opened, the control unit 80 can control the turbine pump to operate to drive the phosphoric acid solution in the metering bin 42 to flow into the feeding unit 50. Preferably, a weighing device is also arranged in the feeding unit 50, so that the weight of the phosphoric acid solution flowing into the feeding unit 50 can be measured. By comparing the weighing data of the metering bin 42 with the weighing data of the feeding unit 50, the feeding amount of the phosphoric acid solution can be further confirmed. When the feeding amount of the phosphoric acid solution is confirmed to be correct, a sixth valve 76 at the bottom of the feeding unit 50 can be opened, so that the phosphoric acid solution enters the premixing tank 20 to prepare the lithium iron phosphate positive electrode material. The present application feeds through the feeding unit 50, and the feeding speed and feeding amount can be adjusted through the sixth valve 76, so that the reaction is not violent, and the safety of the person is ensured.

[0041] It can be understood that in the embodiment of the present application, all parts in contact with the phosphoric acid solution, such as the inner wall 312 of the storage tank, the inner wall of the detection bin 41, the inner wall of the metering bin 42, the inner wall of the feeding unit 50, and the inner wall of the pipeline 60, are coated with an anticorrosion layer to avoid corrosion of the phosphoric acid solution.

[0042] According to the phosphoric acid solution feeding system 100 of the embodiment of the present application, the cooling water absorbing the heat of the kiln 10 is drained to the water pipe 32 outside the storage tank 31 by arranging the water pipe 32 outside the storage tank 31, and the heat of the cooling water is used to keep the phosphoric acid solution warm. On the one hand, the energy utilization efficiency is improved, and the heat loss is reduced. On the other hand, the problem of unbalanced material proportioning caused by crystallization of the phosphoric acid solution can be prevented, and the production cost is reduced. In addition, by arranging the detection bin 41, the concentration of the phosphoric acid is detected, so that the control unit 80 can accurately calculate the feeding amount of the phosphoric acid solution. By arranging the metering bin 42 and the feeding unit 50, the measurement accuracy of the feeding amount of the phosphoric acid solution is further improved, so that the indicators of the lithium iron phosphate positive electrode material produced due to unbalanced material proportioning are avoided. In addition, the phosphoric acid solution feeding system 100 of the present application realizes high automation through the control unit 80, reduces human intervention, reduces labor cost, and ensures accurate process control and improves the qualified rate of finished products.

[0043] In the present application, unless otherwise clearly specified and limited, the terms such as "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense. For example, it can be fixed connection, or detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] In the description of the specification, the description using the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the particular feature, structure, material or characteristic being described is included in at least one embodiment or example of the present application. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the description herein of certain examples does not necessarily exclude these examples from the scope of the application, and these examples can be combined with each other for the purpose of patentable inventions.

[0045] Although the embodiments of the present application have been shown and described, it would be appreciated by those skilled in the art that changes, modifications, alternatives and variations to these embodiments could be made without departing from the principles and spirit of the application, and the scope of the application is defined by the claims and their equivalents.

Claims

1. A phosphoric acid solution feeding system applied to a lithium iron phosphate positive electrode material production line, characterized in that, The phosphoric acid solution feeding system comprises a storage unit for storing the phosphoric acid solution, a metering unit and a control unit, the storage unit is connected with the metering unit through a pipeline, the metering unit comprises a detection chamber and a metering chamber, the detection chamber is used for detecting the concentration of the phosphoric acid solution flowing therethrough, the control unit calculates the required feeding amount of the phosphoric acid solution according to the detected concentration of the phosphoric acid solution, and controls the phosphoric acid solution in the storage unit to flow into the metering chamber according to the feeding amount of the phosphoric acid solution, and the metering chamber detects the weight of the phosphoric acid solution flowing thereto. At least one concentration detection device is arranged in the detection chamber, the concentration detection device sends the detected concentration of the phosphoric acid solution to the control unit after detecting the concentration of the phosphoric acid solution, and the control unit calculates the required feeding amount of the phosphoric acid solution according to the detected concentration of the phosphoric acid solution; a third valve and a fourth valve are respectively arranged at the outlet of the detection chamber, when the concentration of the phosphoric acid solution detected by the concentration detection device meets the requirement, the control unit controls the third valve to be closed and the fourth valve to be opened, so that the phosphoric acid solution flows into the metering chamber; when the concentration of the phosphoric acid solution detected by the concentration detection device does not meet the requirement, the control unit controls the third valve to be opened and the fourth valve to be closed, so that the phosphoric acid solution does not flow into the metering chamber.

2. The phosphoric acid solution feeding system according to claim 1, wherein The storage unit comprises a storage tank for storing the phosphoric acid solution and a water pipe, the storage tank comprises an outer wall and an inner wall, a hollow jacket layer is arranged between the outer wall and the inner wall, and the water pipe is accommodated in the jacket layer.

3. The phosphoric acid solution feeding system according to claim 2, wherein The water pipe is spirally wound outside the inner wall, hot water is accommodated in the water pipe, and the hot water is used for heat preservation of the phosphoric acid solution in the storage tank.

4. The phosphoric acid solution feeding system according to claim 3, wherein The lithium iron phosphate anode material production line comprises a kiln and a kiln cooling area, the kiln cooling area contains cooling water for absorbing heat of the kiln, a water inlet of the water pipe is connected with the kiln cooling area, and the cooling water absorbing the heat of the kiln in the kiln cooling area flows into the water pipe to transfer the heat to the phosphoric acid solution in the storage tank, so that the phosphoric acid solution is heat preserved.

5. The phosphoric acid solution feeding system according to claim 1, wherein The phosphoric acid solution feeding system is provided with a flow meter at the fourth valve, the flow meter is used for counting the flow of the phosphoric acid solution flowing through the fourth valve in real time, and sends a signal to the control unit when the feeding amount of the phosphoric acid solution is reached, and the control unit controls the fourth valve to be closed, so that the phosphoric acid solution stops flowing into the metering chamber.

6. The phosphoric acid solution feeding system according to claim 1, wherein A weighing device is arranged in the metering chamber, the weighing device is used for measuring the weight of the phosphoric acid solution flowing into the metering chamber, and the metering chamber sends a signal to the control unit when the weight of the phosphoric acid solution flowing into the metering chamber reaches the feeding amount calculated by the control unit, and the control unit controls the phosphoric acid solution to stop flowing into the metering chamber.

7. The phosphoric acid solution feeding system according to claim 1, wherein The phosphoric acid solution feeding system further comprises a feeding unit, the feeding unit is connected with the metering unit through a pipeline, and a weighing device is arranged in the feeding unit, the weighing device is used for measuring the weight of the phosphoric acid solution flowing into the feeding unit.

8. The phosphoric acid solution feeding system according to claim 7, wherein The storage unit, the metering unit, the feeding unit and the pipeline are coated with an anticorrosion layer at positions contacted with the phosphoric acid solution.

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