Pretreatment system for detecting oxygen content of hexamethylenediamine storage tank

Abstract

The utility model belongs to the technical field of hexamethylenediamine detection, and particularly relates to a pretreatment system for detecting the oxygen content of a hexamethylenediamine storage tank. Comprising a first washing tank, a second washing tank, a coarse filter, a drying pipe and a monitoring filter which are sequentially connected, an inlet of the first washing tank is connected with an outlet of a hexamethylenediamine storage tank through a pipeline, and a flow regulating valve and a pressure sensor are arranged on the pipeline between the first washing tank and the hexamethylenediamine storage tank; a humidity sensor is arranged on an outlet pipeline of the monitoring filter, an outlet of the monitoring filter is respectively connected to an oxygen content analyzer and waste gas treatment equipment through pipelines, and a first electromagnetic valve and a second electromagnetic valve are respectively arranged on the pipelines. Through the arrangement of the water washing unit, the filtering unit, the drying unit and other treatment units, corrosive media and interference components in a mixed gas phase are effectively blocked, and it is ensured that the oxygen content analyzer can accurately and stably measure the oxygen content in the hexamethylenediamine storage tank.

Description

Technical Field

[0001] The utility model belongs to the technical field of hexamethylenediamine detection, and particularly relates to a pretreatment system for detecting the oxygen content in a hexamethylenediamine storage tank. Background Art

[0002] As a key raw material for nylon production, the physical and chemical stability of hexamethylenediamine directly affects the performance indicators of nylon products. To avoid the oxidation and deterioration of hexamethylenediamine during storage, a nitrogen replacement process is required to maintain an inert nitrogen environment in the storage tank to isolate the influence of oxygen on its quality.

[0003] However, hexamethylenediamine has the characteristic of easy crystallization, and a constant temperature storage condition of 50 - 55 °C needs to be maintained for a long time to ensure its fluidity. Under this temperature condition, part of the hexamethylenediamine will volatilize into gas and mix with the nitrogen in the storage tank to form a nitrogen-hexamethylenediamine mixed gas phase. When it is necessary to detect the oxygen content in the hexamethylenediamine storage tank, the alkaline gas and particulate matter in the mixed gas phase directly enter the oxygen analyzer, which easily causes sensor corrosion, pipeline blockage, and detection data distortion, seriously shortening the service life of the equipment. Therefore, it is very necessary to develop a pretreatment system that can effectively purify the gas to be detected. Summary of the Utility Model

[0004] According to the above deficiencies in the prior art, the purpose of the utility model is to provide a pretreatment system for detecting the oxygen content in a hexamethylenediamine storage tank. By setting up treatment units such as water washing, filtration, and drying, the corrosive media and interfering components in the mixed gas phase are effectively blocked, ensuring that the oxygen content analyzer can accurately and stably measure the oxygen content in the hexamethylenediamine storage tank.

[0005] The utility model is realized by adopting the following technical solutions:

[0006] The pretreatment system for detecting the oxygen content in a hexamethylenediamine storage tank includes a first water washing tank, a second water washing tank, a coarse filter, a drying tube, and a monitoring filter connected in sequence. The inlet of the first water washing tank is connected to the outlet of the hexamethylenediamine storage tank through a pipeline. A flow regulating valve and a pressure sensor are provided on the pipeline between the first water washing tank and the hexamethylenediamine storage tank. The inlet pipelines of the first water washing tank and the second water washing tank extend below the liquid level in their respective tanks; a humidity sensor is provided on the outlet pipeline of the monitoring filter. The outlet of the monitoring filter is connected to an oxygen content analyzer and an exhaust gas treatment device through pipelines, and a first solenoid valve and a second solenoid valve are respectively provided on the pipelines. It also includes a control system.

[0007] The tops of the first water washing tank and the second water washing tank are respectively connected with water inlet pipelines, and pneumatic water inlet valves are provided on the water inlet pipelines, and automatic drain valves are respectively provided at the bottoms.

[0008] The interiors of the first water washing tank and the second water washing tank are respectively provided with float type liquid level gauges.

[0009] The interior of the drying tube is filled with discolored silica gel desiccant, and an observation window is provided on the outer wall of the drying tube.

[0010] A check valve is provided on the pipeline between the coarse filter and the drying tube, and an on-line cleaning interface is provided between the coarse filter and the check valve. The on-line cleaning interface is connected to an external high-pressure cleaning device through a quick-release flange, and the cleaning medium is deionized water.

[0011] A heat tracing device is provided on the pipeline between the hexamethylenediamine storage tank and the first water washing tank.

[0012] The control system is respectively electrically connected to the flow regulating valve, the pressure sensor, the humidity sensor, the first solenoid valve, the second solenoid valve, the pneumatic water inlet valve, the automatic drain valve and the float type liquid level gauge.

[0013] The pretreatment system for detecting the oxygen content in the hexamethylenediamine storage tank has the following working principle:

[0014] The gas in the hexamethylenediamine storage tank is extracted through a pipeline and sent into the first water washing tank. During the extraction process, the flow rate of the gas is controlled by the flow regulating valve provided on the pipeline to ensure the stability of the gas volume entering the system. At the same time, the pressure in the pipeline is monitored in real time by the pressure sensor to ensure the safety of the gas transportation process. At the same time, a heat tracing device is also provided on the pipeline between the hexamethylenediamine storage tank and the first water washing tank to maintain the pipeline temperature and prevent hexamethylenediamine from crystallizing in the pipeline.

[0015] Two-stage purification is carried out through the first water washing tank and the second water washing tank, which can remove most of the water-soluble impurities and particulate matters in the gas. The inlet pipelines of the two water washing tanks both extend below the liquid level in their respective tanks to ensure that the gas is fully in contact with water and achieve the washing effect. At the same time, the liquid level information is fed back to the control system in real time through the float type liquid level gauge, and automatic water replenishment and drainage are realized through the pneumatic water inlet valve and the automatic drain valve to ensure that the liquid level in the water washing tank is within a safe range.

[0016] The gas after water washing treatment enters the primary filter to further remove larger particulate matters and impurities, and then enters the drying tube for drying. The drying tube is filled with discolored silica gel desiccant to remove the moisture in the gas, ensuring that the gas remains dry before entering the oxygen content analyzer and avoiding the influence of high moisture content on the oxygen content detection. The operator can check the state of the desiccant through the observation window set on the outer wall of the drying tube. A check valve is installed on the pipeline between the primary filter and the drying tube, and an online cleaning interface is installed between the primary filter and the check valve, which is connected to an external high-pressure cleaning device through a quick-release flange. When the primary filter needs to be cleaned, deionized water can be used as the cleaning medium to clean the primary filter through this interface, and the cleaning water is discharged through the automatic drain valve at the bottom of the second water washing tank.

[0017] The dried gas enters the monitoring filter to further remove tiny particulate matters, ensuring that the gas entering the oxygen content analyzer is pure and free of impurities. A humidity sensor is installed on the outlet pipeline of the monitoring filter to monitor the humidity of the gas in real time, ensuring that the dryness of the gas meets the requirements. The control system intelligently regulates the process flow according to the feedback signal of the humidity sensor: when the detected humidity meets the standard, the first solenoid valve is opened to convey the qualified sample gas to the oxygen content analyzer; if the humidity exceeds the standard, the second solenoid valve is activated to introduce the gas into the waste gas treatment equipment. By closing the flow regulating valve and stopping the intake, the operator can timely replace the discolored silica gel desiccant in the drying tube.

[0018] During the whole process, the control system conducts integrated monitoring on the pressure, flow rate, liquid level, and humidity parameters of each unit, and realizes the full-automatic operation of the system by adjusting the opening and closing and the opening degree of each valve.

[0019] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0020] Through multi-stage collaborative treatment (water washing, filtering, drying) and intelligent control, the present utility model effectively solves the problem of analyzer damage caused by the easy volatilization and crystallization of hexamethylenediamine and the mixing of gas during the oxygen content detection of the hexamethylenediamine storage tank. The system has a high integration degree, can remove the alkaline components and particulate matters in the gas, ensuring the accuracy of the detection process and the service life of the instrument; through automatic interlock control and online maintenance design (such as automatic drainage, heat tracing to prevent crystallization, online cleaning), the labor intensity of manual operation is reduced, and the stability of industrial continuous operation is guaranteed. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the pretreatment system for oxygen content detection of the hexamethylenediamine storage tank described in the present utility model;

[0022] In the figure: 1. First water washing tank; 2. Second water washing tank; 3. Coarse filter; 4. Drying pipe; 5. Monitoring filter; 6. Hexamethylenediamine storage tank; 7. Flow regulating valve; 8. Pressure sensor; 9. Humidity sensor; 10. Oxygen content analyzer; 11. Waste gas treatment equipment; 12. First solenoid valve; 13. Second solenoid valve; 14. Pneumatic water inlet valve; 15. Automatic drain valve; 16. Float type liquid level gauge; 17. Color-changing silica gel desiccant; 18. Observation window; 19. Check valve; 20. High-pressure cleaning equipment; 21. Heat tracing device. Detailed implementation mode

[0023] In order to make the purpose and technical solution of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0024] Embodiment 1

[0025] As Figure 1 shown, the pretreatment system for oxygen content detection of a hexamethylenediamine storage tank includes a first water washing tank 1, a second water washing tank 2, a coarse filter 3, a drying pipe 4, and a monitoring filter 5 connected in sequence. The inlet of the first water washing tank 1 is connected to the outlet of the hexamethylenediamine storage tank 6 through a pipeline. A flow regulating valve 7 and a pressure sensor 8 are provided on the pipeline between the first water washing tank 1 and the hexamethylenediamine storage tank 6. The inlet pipelines of the first water washing tank 1 and the second water washing tank 2 extend below the liquid level in their respective tanks; a humidity sensor 9 is provided on the outlet pipeline of the monitoring filter 5. The outlet of the monitoring filter 5 is connected to an oxygen content analyzer 10 and waste gas treatment equipment 11 through pipelines, and a first solenoid valve 12 and a second solenoid valve 13 are respectively provided on the pipelines, and a control system is also included.

[0026] The top parts of the first water washing tank 1 and the second water washing tank 2 are respectively connected with water inlet pipelines, and a pneumatic water inlet valve 14 is provided on the water inlet pipelines, and automatic drain valves 15 are respectively provided at the bottoms.

[0027] Float type liquid level gauges 16 are respectively provided inside the first water washing tank 1 and the second water washing tank 2.

[0028] The inside of the drying pipe 4 is filled with a color-changing silica gel desiccant 17, and an observation window 18 is provided on the outer wall of the drying pipe 4.

[0029] A check valve 19 is provided on the pipeline between the coarse filter 3 and the drying pipe 4, and an on-line cleaning interface is provided between the coarse filter 3 and the check valve 19. The on-line cleaning interface is connected to external high-pressure cleaning equipment 20 through a quick-release flange, and the cleaning medium is deionized water.

[0030] A heat tracing device 21 is provided on the pipeline between the hexamethylenediamine storage tank 6 and the first water washing tank 1.

[0031] The described control system is electrically connected to a flow regulating valve 7, a pressure sensor 8, a humidity sensor 9, a first solenoid valve 12, a second solenoid valve 13, a pneumatic water inlet valve 14, an automatic drain valve 15, and a float type liquid level gauge 16 respectively.

[0032] During operation, the specific steps are as follows:

[0033] First, the gas in the hexamethylenediamine storage tank 6 is introduced into the first water washing tank 1 through a pipeline. During this process, the flow regulating valve 7 precisely controls the gas flow rate to ensure that the gas volume entering the system remains in a stable state. At the same time, the pressure sensor 8 continuously monitors and feeds back the pressure data in the pipeline to ensure the safety and stability of gas transportation. In addition, in order to prevent hexamethylenediamine from crystallizing in the pipeline under low temperature conditions, the tracing device 21 is used to maintain the appropriate temperature of the pipeline.

[0034] The gas enters the first water washing tank 1 through the inlet pipeline extending below the liquid level, and the gas comes into full contact with the water in the first water washing tank 1, thereby effectively removing most of the water-soluble impurities and particulate matters therein. Meanwhile, the float type liquid level gauge 16 monitors the liquid level change in the first water washing tank 1 in real time and transmits the data to the control system. The control system adjusts the opening and closing of the pneumatic water inlet valve 14 and the automatic drain valve 15 accordingly to ensure that the water level in the first water washing tank 1 remains within a safe and effective range.

[0035] After the first-stage water washing is completed, the gas continues to enter the second water washing tank 2 for further purification treatment to achieve further removal of impurities.

[0036] The gas that has undergone two-stage water washing enters the coarse filter 3, which further captures and removes larger particulate matters and impurities in the gas. Subsequently, the gas enters the drying tube 4, where the discoloring silica gel desiccant 17 filled therein effectively absorbs the moisture in the gas to ensure that the gas is in a dry state before entering the oxygen content analyzer 10. The operator can directly check the color change of the desiccant through the observation window 18 to determine whether it needs to be replaced. An on-line cleaning interface is provided between the coarse filter 3 and the check valve 19. Periodically, an external high-pressure cleaning device 20 is connected through a quick-release flange to clean the coarse filter 3 with deionized water. The water after cleaning is discharged through the automatic drain valve 15 of the second water washing tank 2.

[0037] The gas enters the monitoring filter 5 through the drying tube 4 to further remove tiny particulate matters, ensuring that the gas entering the oxygen content analyzer 10 is pure and free of impurities. On the outlet pipeline of the monitoring filter 5, the humidity sensor 9 monitors the humidity of the gas in real time to ensure that the dryness of the gas meets the standard. If the humidity sensor 9 feedbacks that the humidity meets the standard, the control system will open the first solenoid valve 12 to deliver the qualified gas sample to the oxygen content analyzer 10; if the humidity exceeds the standard, the second solenoid valve 13 will be started to introduce the gas into the waste gas treatment equipment 11, and the flow regulating valve 7 will be closed to stop the intake of gas. At the same time, the operator will be reminded to replace the discolored silica gel desiccant 17 in the drying tube 4.

[0038] Throughout the working process, the control system always conducts integrated monitoring on the key parameters such as pressure, flow rate, liquid level, humidity, etc. of each unit, and intelligently adjusts the opening and closing and opening degree of each valve according to the real-time data to realize the full-automatic operation of the system.

Claims

1. A pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank, characterized in that: The invention comprises a first water washing tank (1), a second water washing tank (2), a coarse filter (3), a drying pipe (4) and a monitoring filter (5) which are connected in sequence. The inlet of the first water washing tank (1) is connected to the outlet of the hexamethylenediamine storage tank (6) through a pipeline. A flow regulating valve (7) and a pressure sensor (8) are provided on the pipeline between the first water washing tank (1) and the hexamethylenediamine storage tank (6). The inlet pipelines of the first water washing tank (1) and the second water washing tank (2) are extended below the liquid level in the respective tank bodies. A humidity sensor (9) is provided on the outlet pipeline of the monitoring filter (5); the outlet of the monitoring filter (5) is connected to an oxygen content analyzer (10) and an exhaust gas treatment device (11) through pipelines, respectively; a first solenoid valve (12) and a second solenoid valve (13) are provided on the pipelines, respectively; and a control system is also included.

2. The pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank according to claim 1, characterized in that: The tops of the first water washing tank (1) and the second water washing tank (2) are respectively connected to water inlet pipelines, on which pneumatic water inlet valves (14) are provided, and the bottoms are respectively provided with automatic drain valves (15).

3. The pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank according to claim 2, characterized in that: The first water washing tank (1) and the second water washing tank (2) are each provided with a float type liquid level gauge (16) inside.

4. The pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank according to claim 1, characterized in that: The interior of the drying tube (4) is filled with a color-changing silica gel desiccant (17), and an observation window (18) is provided on the outer wall of the drying tube (4).

5. The pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank according to claim 1, characterized in that: A check valve (19) is provided on the pipeline between the coarse filter (3) and the drying pipe (4), and an online cleaning interface is provided between the coarse filter (3) and the check valve (19). The online cleaning interface is connected to an external high-pressure cleaning device (20) via a quick-release flange, and the cleaning medium is deionized water.

6. The pretreatment system for detecting oxygen content in a hexamethylenediamine storage tank according to claim 1, characterized in that: A heating device (21) is provided on the pipeline between the hexamethylenediamine storage tank (6) and the first water washing tank (1).

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