Crude adipic acid crystallization point detection system

Abstract

The invention belongs to the technical field of adipic acid production equipment, and particularly relates to a crude adipic acid crystallization point detection system which comprises a crystallization point detection tank, a crude adipic acid solution storage tank, a crude adipic acid solution delivery pump, a feeding three-way control electromagnetic valve, a cooling water recovery tank and a crystallization point automatic detection time sequence controller. The crystallization point automatic detection time sequence controller is provided with a main signal connecting line; a thermometer is arranged outside the crystallization point detection tank; an electrode type liquid level alarm controller is also arranged at the top end of the crystallization point detection tank; a first discharge pipe is arranged at the bottom end of the crystallization point detection tank. According to the system, the structure of the crystallization point detection tank is improved, and the automatic feeding detection time sequence is optimized, so that the continuous automatic detection and recording of the crystallization point of the crude adipic acid are realized, reliable data support is provided for the production and purification operation of the crude adipic acid, and the stable operation of the device is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of adipic acid production equipment, and particularly relates to a detection system for the crystallization point of crude adipic acid. Background Art

[0002] The oxidation reaction process is the core process in the adipic acid production process. The crude adipic acid generated in the oxidation reaction process is purified and dried to obtain a qualified external sales product. The crystallization point is an important control parameter in the oxidation process and the main basis for adjusting the raw material ratio. On the one hand, this parameter can characterize whether the operation state of the reaction process is normal, and on the other hand, it provides a necessary basis for controlling the temperature and vacuum state of each chamber of the crystallizer in the refining and purification process. Therefore, the detection of the crystallization point must be accurate and reliable.

[0003] Based on this, the present invention provides a detection system for the crystallization point of crude adipic acid. This system measures the crystallization point of crude adipic acid by adopting an automatic feeding and continuous detection method, thereby determining the concentration of the crude adipic acid solution and ensuring the quality of the refined adipic acid product. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a detection system for the crystallization point of crude adipic acid. This system is practical and reliable, and can solve technical problems such as poor continuity of the original detection system, emission of nitrous gas at the site, easy overflow of materials, large error in detection data, and high consumption of public works. The system of the present invention improves the structure of the crystallization point detection tank and optimizes the automatic feeding and detection timing sequence, realizing continuous and automatic detection and recording of the crystallization point of crude adipic acid, providing reliable data support for the production and purification operations of crude adipic acid, and ensuring the stable operation of the device.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: A detection system for the crystallization point of crude adipic acid, comprising a crystallization point detection tank, a crude adipic acid solution storage tank, a crude adipic acid solution transfer pump, a feed three-way control solenoid valve, a cooling water recovery tank, and a crystallization point automatic detection timing controller; The crystallization point automatic detection timing controller is provided with a main signal connection line; A thermometer is provided outside the crystallization point detection tank; An electrode type liquid level alarm controller is further provided at the top of the crystallization point detection tank; A first discharge pipe is provided at the bottom of the crystallization point detection tank; the output end of the first discharge pipe is communicated with the crude adipic acid solution storage tank; A detection tank jacket is provided on the outer periphery of the crystallization point detection tank. The detection tank jacket is hollow, and the detection tank jacket is communicated with an external cooling water inlet system through a coolant inlet pipe; The coolant inlet pipe is also provided with a low-pressure steam inlet pipe, and the low-pressure steam inlet pipe is connected to an external low-pressure steam system; An overflow port is provided at the upper part of the crystallization point detection tank, and the overflow port is connected to a high-low level overflow pipeline; A jacket cooling water return pipeline is also provided at the top end of the detection tank jacket, and the output end of the jacket cooling water return pipeline is connected to a cooling water recovery tank; A second discharge pipe is also provided at the bottom end of the jacket, and the output end of the second discharge pipe discharges to the external drain; A crude adipic acid solution storage tank is provided with a crude adipic acid storage tank discharge pipe at the bottom end, and the crude adipic acid solution storage tank is connected to the inlet end of a crude adipic acid solution delivery pump through the crude adipic acid storage tank discharge pipe; The output end of the crude adipic acid solution delivery pump is connected to the inlet end of a feed three-way control solenoid valve through a crude adipic acid solution delivery pump discharge pipe; The feed three-way control solenoid valve is provided with two outlet ends, namely a first outlet end and a second outlet end. The first outlet end of the feed three-way control solenoid valve is connected to the high-low level overflow pipeline through a pipeline, and the second outlet end of the feed three-way control solenoid valve is connected to the crystallization point detection tank through a feed pipeline.

[0006] Furthermore, an impeller type agitator is installed inside the crystallization point detection tank. The stirring shaft of the impeller type agitator extends out from the top of the crystallization point detection tank, and the stirring shaft is connected to a stirring motor.

[0007] Furthermore, a drain valve is provided on the first discharge pipe.

[0008] Furthermore, the temperature sensing end of the thermometer extends into the crystallization point detection tank, and the thermometer is provided with a temperature signal output end. The temperature signal output end is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a first signal output line.

[0009] Furthermore, the electrode type liquid level alarm controller is provided with a liquid level signal output end. The liquid level signal output end is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a second signal output line.

[0010] Furthermore, a cooling water inlet control valve is provided at the connection between the coolant inlet pipe and the external cooling water inlet system. The cooling water inlet control valve is an electromagnetic control valve, and the cooling water inlet control valve is provided with an inlet signal output end. The inlet signal output end is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a third signal output line.

[0011] Further, a low-pressure steam inlet control valve is provided at the connection between the low-pressure steam inlet pipe and the external low-pressure steam system. The low-pressure steam inlet control valve is an electromagnetic control valve, and the low-pressure steam inlet control valve is provided with a steam inlet signal output terminal. The steam inlet signal output terminal is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a fourth signal output line.

[0012] Further, a jacket cooling water return control valve is provided on the jacket cooling water return pipeline. The jacket cooling water return control valve is an electromagnetic control valve, and the jacket cooling water return control valve is provided with a return water signal output terminal. The return water signal output terminal is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a fifth signal output line.

[0013] Further, the output end of the high and low level overflow pipeline is connected to the first discharge pipe; when the liquid material in the crystallization point detection tank is too much, it can be discharged through the overflow port and returned to the crude adipic acid solution storage tank.

[0014] Further, a gas phase pipeline is also provided at the top of the crystallization point detection tank. The output end of the gas phase pipeline is connected to the external nitrous gas recovery system; a nitrous gas discharge valve is provided on the gas phase pipeline. By connecting the high and low level overflow pipeline to the crude adipic acid solution storage tank and the gas phase pipeline to the inlet of the nitrous gas recovery system, the micro negative pressure in the crystallization point detection tank can be controlled.

[0015] Further, a steam condensate discharge control valve is provided on the second discharge pipe; the steam condensate discharge control valve is provided with a condensate signal output terminal. The condensate signal output terminal is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a sixth signal output line.

[0016] Further, a crude adipic acid discharge valve is provided on the discharge pipe of the crude adipic acid storage tank.

[0017] Further, a first manual valve is provided on the discharge pipe of the crude adipic acid solution delivery pump.

[0018] Further, the feed three-way control solenoid valve is provided with a three-way control signal output terminal. The three-way control signal output terminal is electrically connected to the main signal connection line of the crystallization point automatic detection timing controller through a seventh signal output line.

[0019] Further, the crystallization point automatic detection timing controller of the present invention can adopt a conventional timing controller in the prior art. For example, devices such as the ACTD-800 hot runner timing controller, the MD18 temperature control hot runner card mold timing controller for the heating runner, and the ASCO timing controller E909 series. And its structure is not the inventive point of the present invention, so it will not be described in detail.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention realizes the continuous and stable detection of the crystallization point of the crude adipic acid solution in the production of adipic acid, providing reliable data basis for the raw material ratio in the crude adipic acid production process and the setting of control parameters for each chamber of the crystallizer. To a certain extent, it ensures the high quality of the refined adipic acid product.

[0021] 2. The detection system for the crystallization point of the crude adipic acid described in the present invention operates stably, with reliable data and strong continuity during the operation process. After improving the original crystallization point detection system, it solves the problems of nitrous gas leakage, high consumption of public utilities, easy overflow of materials, and large detection data errors during the operation of the original system, realizing the long-term stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the detection system for the crystallization point of the crude adipic acid described in Embodiment 1; In the figure: 1. Jacket cooling water return control valve, 2. Jacket cooling water return pipeline, 3. Gas pipeline, 4. Electrode type liquid level alarm controller, 5. High and low level overflow pipeline, 6. Thermometer, 7. Feed three-way control solenoid valve, 8. Feed pipeline, 9. Crude adipic acid solution transfer pump, 10. Crude adipic acid solution storage tank, 11. Crystallization point automatic detection timing controller, 12. Cooling water inlet control valve, 13. Steam condensate discharge control valve, 14. Low-pressure steam inlet control valve, 15. Crystallization point detection tank, 16. Coolant inlet pipe, 17. Second discharge pipe, 18. First discharge pipe, 19. Drain valve, 20. Cooling water recovery tank, 31. Nitrous gas discharge valve, 91. Crude adipic acid storage tank discharge pipe, 92. Crude adipic acid solution transfer pump discharge pipe, 93. First manual valve, 94. Crude adipic acid discharge valve, 111. Main signal connection line, 112. First signal output line, 113. Second signal output line, 114. Third signal output line, 115. Fourth signal output line, 116. Fifth signal output line, 117. Sixth signal output line, 118. Seventh signal output line. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be further described below in conjunction with the embodiments and the drawings, but it is not a limitation to the present invention.

[0024] In the description of the present invention, it should be noted that for the orientation terms, if there are terms such as "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation and position relationship is based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing 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 should not be construed as limiting the specific protection scope of the present invention.

[0025] It should be noted that the terms "first", "second", "third", "1#", "2#", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances for the embodiments of this application described herein.

[0026] Embodiment 1 As Figure 1 shown, a detection system for the crystallization point of crude adipic acid includes a crystallization point detection tank 15, a crude adipic acid solution storage tank 10, a crude adipic acid solution transfer pump 9, a feed three-way control solenoid valve 7, a cooling water recovery tank 20, and a crystallization point automatic detection timing controller 11; An impeller type agitator is installed inside the crystallization point detection tank 15. The stirring shaft of the impeller type agitator extends from the top of the crystallization point detection tank 15, and the stirring shaft is connected to a stirring motor; The crystallization point automatic detection timing controller 11 is provided with a main signal connection line 111; A thermometer 6 is provided outside the crystallization point detection tank 15. The temperature sensing end of the thermometer 6 extends into the crystallization point detection tank 15, and the thermometer 6 is provided with a temperature signal output end. The temperature signal output end is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a first signal output line 112; An electrode type liquid level alarm controller 4 is further provided at the top end of the crystallization point detection tank 15. The electrode type liquid level alarm controller 4 is provided with a liquid level signal output end. The liquid level signal output end is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a second signal output line 113; A first discharge pipe 18 is provided at the bottom end of the crystallization point detection tank 15. A drain valve 19 is provided on the first discharge pipe 18; the output end of the first discharge pipe 18 is communicated with the crude adipic acid solution storage tank 10; A detection tank jacket is provided on the outer periphery of the crystallization point detection tank 15. The detection tank jacket is hollow, and the detection tank jacket is communicated with an external cooling water inlet system through a coolant inlet pipe 16. A cooling water inlet control valve 12 is provided at the connection between the coolant inlet pipe 16 and the external cooling water inlet system. The cooling water inlet control valve 12 is an electromagnetic control valve. The cooling water inlet control valve 12 is provided with an inlet signal output end. The inlet signal output end is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a third signal output line 114; A low-pressure steam inlet pipe (not marked in the figure) is also provided on the coolant inlet pipe 16. The low-pressure steam inlet pipe is connected to an external low-pressure steam system. A low-pressure steam inlet control valve 14 is provided at the connection between the low-pressure steam inlet pipe and the external low-pressure steam system. The low-pressure steam inlet control valve 14 is an electromagnetic control valve. The low-pressure steam inlet control valve 14 is provided with a steam inlet signal output terminal, and the steam inlet signal output terminal is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a fourth signal output line 115; In the present invention, external high-purity cooling water and low-pressure steam are used as heat exchange media and introduced into the jacket of the detection tank to exchange heat with the crystallization point detection tank 15; A jacket cooling water return pipeline 2 is also provided at the top of the jacket of the detection tank. The output end of the jacket cooling water return pipeline 2 is connected to a cooling water recovery tank 20; A jacket cooling water return control valve 1 is provided on the jacket cooling water return pipeline 2. The jacket cooling water return control valve 1 is an electromagnetic control valve. The jacket cooling water return control valve 1 is provided with a return water signal output terminal, and the return water signal output terminal is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a fifth signal output line 116; An overflow port is provided at the upper part of the crystallization point detection tank 15. The overflow port is connected to a high-low level overflow pipeline 5. The output end of the high-low level overflow pipeline 5 is connected to a first discharge pipe 18; When the liquid material in the crystallization point detection tank 15 is too much, it can be discharged through the overflow port and returned to the crude adipic acid solution storage tank 10; A gas phase pipeline 3 is also provided at the top of the crystallization point detection tank 15. The output end of the gas phase pipeline 3 is connected to an external nitrous gas recovery system; A nitrous gas discharge valve 31 is provided on the gas phase pipeline 3; In addition, by connecting the high-low level overflow pipeline 5 to the crude adipic acid solution storage tank 10 and connecting the gas phase pipeline 3 to the inlet of the nitrous gas recovery system, the micro-negative pressure in the crystallization point detection tank 15 is controlled; A second discharge pipe 17 is also provided at the bottom of the jacket. The output end of the second discharge pipe 17 is discharged to the trench. A steam condensate discharge control valve 13 is provided on the second discharge pipe 17; The steam condensate discharge control valve 13 is provided with a condensate signal output terminal, and the condensate signal output terminal is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a sixth signal output line 117.

[0027] A crude adipic acid storage tank discharge pipe 91 is provided at the bottom of the crude adipic acid solution storage tank 10. A crude adipic acid discharge valve 94 is provided on the crude adipic acid storage tank discharge pipe 91. The crude adipic acid solution storage tank 10 is connected to the inlet end of a crude adipic acid solution delivery pump 9 through the crude adipic acid storage tank discharge pipe 91; The output end of the crude adipic acid solution transfer pump 9 is connected to the inlet end of the feed three-way control solenoid valve 7 through the crude adipic acid solution transfer pump discharge pipe 92, and a first manual valve 93 is provided on the crude adipic acid solution transfer pump discharge pipe 92; The feed three-way control solenoid valve 7 is provided with two outlet ends, namely a first outlet end and a second outlet end. The first outlet end of the feed three-way control solenoid valve 7 is connected to the high and low level overflow pipeline 5 through a pipeline, and the second outlet end of the feed three-way control solenoid valve 7 is connected to the middle part of the crystallization point detection tank 15 through the feed pipeline 8.

[0028] The feed three-way control solenoid valve 7 is provided with a three-way control signal output end, and the three-way control signal output end is electrically connected to the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through a seventh signal output line 118.

[0029] The crystallization point automatic detection timing controller 11 described in the present invention can adopt a conventional timing controller in the prior art. For example, devices such as the ACTD-800 hot runner timing controller, the MD18 temperature control hot runner card die timing controller for the heating runner, and the ASCO timing controller E909 series, and its structure is not the inventive point of the present invention, so it will not be elaborated here.

[0030] Among them, the electrical connection method between the temperature signal output end of the thermometer 6 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the first signal output line 112, the electrical connection method between the liquid level signal output end of the electrode type liquid level alarm controller 4 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the second signal output line 113, the electrical connection method between the water inlet signal output end of the cooling water inlet control valve 12 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the third signal output line 114, the electrical connection method between the steam inlet signal output end of the low-pressure steam inlet control valve 14 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the fourth signal output line 115, the electrical connection method between the return water signal output end of the jacket cooling water return control valve 1 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the fifth signal output line 116, the electrical connection method between the condensate signal output end of the steam condensate discharge control valve 13 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the sixth signal output line 117, and the electrical connection method between the three-way control signal output end of the feed three-way control solenoid valve 7 and the main signal connection line 111 of the crystallization point automatic detection timing controller 11 through the seventh signal output line 118 all adopt conventional means in the prior art.

[0031] The thermometer 6, the cooling water inlet control valve 12, the low-pressure steam inlet control valve 14, the jacket cooling water return control valve 1, the steam condensate discharge control valve 13, and the feed three-way control solenoid valve 7 all adopt equipment of conventional models in the prior art, and their structures are not the inventive points of the present invention, so they will not be described in detail.

[0032] The control mode of the crystallization point automatic detection timing controller 11 for the thermometer 6, the electrode type liquid level alarm controller 4, the cooling water inlet control valve 12, the low-pressure steam inlet control valve 14, the jacket cooling water return control valve 1, the steam condensate discharge control valve 13, and the feed three-way control solenoid valve 7 can adopt the conventional settings in the prior art, and it is not the inventive point of the present invention, so it will not be described in detail.

[0033] The described crystallization point automatic detection timing controller 11 can set the detection steps according to the timing, heat and cool and crystallize the detection solution to obtain its temperature change curve, and obtain the crystallization point of the detection solution according to the change characteristics of the curve slope.

[0034] The present invention realizes the continuous and stable detection of the crystallization point of the crude adipic acid solution in the production of adipic acid, provides a reliable data basis for the raw material ratio in the production process of crude adipic acid and the setting of the control parameters of each chamber of the crystallizer, and guarantees the high quality of the refined adipic acid product to a certain extent.

[0035] The detection process of the detection system for the crystallization point of the crude adipic acid described in the present invention is as follows: (1) Liquid filling process: Before the system runs, the feed three-way control solenoid valve 7, the drain valve 19, the cooling water inlet control valve 12, the low-pressure steam inlet control valve 14, the jacket cooling water return control valve 1, the nitrous gas discharge valve 31, the crude adipic acid discharge valve 94, and the first manual valve 93 are all set to the closed state; During operation, first open the crude adipic acid discharge valve 94, the crude adipic acid solution transfer pump 9, and the first manual valve 93, discharge the crude adipic acid solution in the crude adipic acid solution storage tank 10, and pump it into the feed three-way control solenoid valve 7 by using the crude adipic acid solution transfer pump 9. Then open the feed three-way control solenoid valve 7, and set the discharge to pass through the second outlet end, and then through the feed pipeline 8, start feeding into the crystallization point detection tank 15. By setting the crystallization point automatic detection timing controller 11 to control the opening time of the three-way control solenoid valve 7 and the discharge time of the second outlet end of the three-way control solenoid valve 7, the time is controlled at 18 minutes, and the feeding stops after reaching the set time; During the liquid filling process, check the state of the electrode type liquid level alarm controller 4. If an alarm occurs, the electrode type liquid level alarm controller 4 sends a stop signal to the crystallization point automatic detection timing controller 11, and the crystallization point automatic detection timing controller 11 stops the detection timing. After the alarm is eliminated and reset, the timing can continue to run; Then, the automatic crystallization point detection timing controller 11 controls the closing of the second outlet end of the feed three-way control solenoid valve 7 and the opening of the first outlet end of the feed three-way control solenoid valve 7. The discharge of the feed three-way control solenoid valve 7 turns to the crude adipic acid solution storage tank 10 for circulation to prevent the crude adipic acid solution delivery pump 9 from being under pressure.

[0036] (2) Heating process: The automatic crystallization point detection timing controller 11 controls the opening of the low-pressure steam inlet control valve 14 and the steam condensate discharge control valve 13. Steam is introduced into the jacket of the detection tank through the external low-pressure steam system to heat the crystallization point detection tank 15. The automatic crystallization point detection timing controller 11 regulates the opening time of the low-pressure steam inlet control valve 14 and the steam condensate discharge control valve 13, with the time controlled at 2 minutes. After reaching the set time, the low-pressure steam inlet control valve 14 and the steam condensate discharge control valve 13 are closed; A small amount of nitrous gas is generated during this process. At this time, the nitrous gas discharge valve 31 is opened, and the nitrous gas is discharged and recycled to the subsequent process through the gas pipeline 3.

[0037] (3) Cooling crystallization process: The automatic crystallization point detection timing controller 11 controls the opening of the cooling water inlet control valve 12 and the jacket cooling water return control valve 1, and controls the closing of the low-pressure steam inlet control valve 14 and the steam condensate discharge control valve 13. High-purity cooling water is introduced into the jacket of the detection tank through the external cooling water inlet system to cool the detected material in the crystallization point detection tank 15. The heat-exchanged high-purity water is recovered through the cooling water return pipeline 2 to reduce the loss of high-purity water; In the crystallization point detection tank 15, during the cooling process of the detection liquid, adipic acid gradually crystallizes out due to the decrease in solubility.

[0038] (4) Generating the crystallization point: During the above cooling crystallization process, the thermometer 6 is used to detect and record the temperature of the detection liquid in the crystallization point detection tank 15 to obtain a temperature curve; The computer analyzes the slope of the temperature curve according to the principle of the crystallization latent heat released during the material crystallization process to automatically generate the crystallization point.

[0039] The thermometer 6 is used to detect the temperature of the solution in the crystallization point detection tank 15. If an alarm occurs, the thermometer 6 sends a stop signal to the automatic crystallization point detection timing controller 11, and the automatic crystallization point detection timing controller 11 then stops the detection timing. After the alarm is eliminated and reset, the timing can continue to run.

[0040] One crystallization detection cycle of the detection system for the crystallization point of the crude adipic acid described in the present invention is about 25 - 35 minutes, preferably 30 minutes. The filling time can be adjusted according to the actual working conditions. The filling time is related to the volume of the crystallization point detection tank 15. If the volume of the crystallization point detection tank 15 is large, the amount of the detection liquid is large, and the required time can be extended.

[0041] After the crystallization point is generated, the automatic detection timing controller 11 of the crystallization point will automatically conduct the next round of detection, enter the next round of liquid filling process, open the feed three-way control solenoid valve 7, and set the discharge to be discharged through the second outlet end, feed the crystallization point detection tank 15, and at the same time, the detection liquid of the previous round can be replaced into the crude adipic acid solution storage tank 10 through the high and low level overflow pipeline 5 to realize the replacement of the detection liquid.

[0042] The detection system for the crystallization point of the crude adipic acid in the present invention operates stably, has reliable data, and strong continuity during the operation process. After improving the original crystallization point detection system, the problems of nitrous gas leakage, high utility consumption, easy material overflow, and large detection data error during the operation of the original system are solved, and the long-term stable operation of the device is realized.

[0043] The above embodiments are illustrative examples of the embodiments of the present invention. The embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A detection system for the crystallization point of crude adipic acid, characterized in that: It includes a crystallization point detection tank, a crude adipic acid solution storage tank, a crude adipic acid solution delivery pump, a feed three-way control solenoid valve, a cooling water recovery tank and a crystallization point automatic detection timing controller; The crystallization point automatic detection timing controller is provided with a main signal connection circuit; A thermometer is provided outside the crystallization point detection tank; The top of the crystallization point detection tank is also provided with an electrode type liquid level alarm controller; A first discharge pipe is provided at the bottom of the crystallization point detection tank; the output end of the first discharge pipe is connected to the crude adipic acid solution storage tank; The outer periphery of the crystallization point detection tank is provided with a detection tank jacket, the detection tank jacket is hollow, and the detection tank jacket is connected to an external cooling water inlet system through a coolant inlet pipe; A low-pressure steam inlet pipe is also provided on the coolant inlet pipe, and the low-pressure steam inlet pipe is connected to an external low-pressure steam system; An overflow port is provided on the upper part of the crystallization point detection tank, and the overflow port is connected to high and low overflow pipelines; The top of the detection tank jacket is also provided with a jacket cooling water return pipeline, and the output end of the jacket cooling water return pipeline is connected to the cooling water recovery tank; The bottom end of the jacket is also provided with a second discharge pipe, and the output end of the second discharge pipe is discharged to the outside of the trench; A crude adipic acid storage tank discharge pipe is provided at the bottom end of the crude adipic acid solution storage tank, and the crude adipic acid solution storage tank is connected to the inlet end of the crude adipic acid solution delivery pump through the crude adipic acid storage tank discharge pipe; The output end of the crude adipic acid solution delivery pump is connected to the inlet end of the feed three-way control solenoid valve through the crude adipic acid solution delivery pump discharge pipe; The feed three-way control solenoid valve is provided with two outlet ends, namely a first outlet end and a second outlet end. The first outlet end of the feed three-way control solenoid valve is connected to the high and low level overflow pipelines through a pipeline, and the second outlet end of the feed three-way control solenoid valve is connected to the crystallization point detection tank through the feed pipeline.

2. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: The temperature sensing end of the thermometer extends into the crystallization point detection tank, and the thermometer is provided with a temperature signal output end, which is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through a first signal output circuit.

3. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: The electrode type liquid level alarm controller is provided with a liquid level signal output terminal, and the liquid level signal output terminal is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through a second signal output circuit.

4. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: A cooling water inlet control valve is provided at the connection between the coolant inlet pipe and the external cooling water inlet system. The cooling water inlet control valve is an electromagnetic control valve. The cooling water inlet control valve is provided with an inlet signal output end. The inlet signal output end is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through a third signal output circuit.

5. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: A low-pressure steam inlet control valve is provided at the connection between the low-pressure steam inlet pipe and the external low-pressure steam system. The low-pressure steam inlet control valve is an electromagnetic control valve. The low-pressure steam inlet control valve is provided with a steam inlet signal output terminal. The steam inlet signal output terminal is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through a fourth signal output circuit.

6. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: A jacket cooling water return control valve is provided on the jacket cooling water return pipeline. The jacket cooling water return control valve is an electromagnetic control valve. The jacket cooling water return control valve is provided with a return signal output terminal. The return signal output terminal is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through the fifth signal output circuit.

7. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: The output ends of the high and low level overflow pipelines are connected to the first discharge pipe.

8. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: A gas phase pipeline is also provided at the top of the crystallization point detection tank, and the output end of the gas phase pipeline is connected to an external nitrous gas recovery system; a nitrous gas discharge valve is provided on the gas phase pipeline.

9. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: A steam condensate discharge control valve is provided on the second discharge pipe; the steam condensate discharge control valve is provided with a condensate signal output terminal, and the condensate signal output terminal is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through a sixth signal output circuit.

10. The detection system for the crystallization point of crude adipic acid according to claim 1, characterized in that: The feed three-way control solenoid valve is provided with a three-way control signal output end, and the three-way control signal output end is electrically connected to the main signal connection circuit of the crystallization point automatic detection timing controller through the seventh signal output circuit.

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