Chloride ion detection system

Abstract

The utility model discloses a chloride ion detection system, which belongs to the technical field of urea hydrolysis ammonia production, and comprises a constant temperature box body, a liquid inlet and a liquid outlet are further arranged on the constant temperature box body, and the liquid inlet is communicated with a first main pipeline; the auxiliary thermostat is arranged in the constant temperature box body, the auxiliary thermostat is communicated with the first main pipeline, and an emptying valve is further arranged on the auxiliary thermostat; and the detection mechanism is connected with the auxiliary thermostat. According to the utility model, the detection mechanism is arranged in the constant-temperature box body, and the reagent in the reagent bottle in the detection mechanism reacts with the urea solution to be detected and then is detected through the spectrophotometer, so that the technical problem that the detection result is influenced due to higher temperature of the urea solution is solved; the technical effect of accurately detecting the concentration of the chloride ions in the urea solution is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of urea hydrolysis to ammonia, and particularly relates to a chloride ion detection system. Background Art

[0002] The urea hydrolysis to ammonia process is an important chemical process. Its principle is to react urea with water under high temperature and high pressure conditions to generate ammonia and carbon dioxide, providing an ammonia source for industrial applications such as flue gas denitrification. In this process, the urea hydrolyzer and its heat exchange coil are key equipment. However, they are often corroded by chloride ions during operation, affecting the service life of the equipment and the stable operation of the system. To ensure the safe and stable operation of the urea hydrolysis to ammonia system, the chloride ion concentration in the urea solution must be strictly controlled. In the actual production process, a chloride ion detection device is usually set in the urea hydrolysis system to monitor the chloride ion concentration in the urea solution and take corresponding measures in a timely manner according to the monitoring results, such as adjusting process parameters, discharging sewage, etc., to avoid corrosion of the equipment caused by too high chloride ion concentration. In the prior art, since the temperature of the urea solution is usually 40 - 50°C, while the temperature adapted by most detection equipment at room temperature is relatively low, directly detecting the urea solution will cause water mist to form on the surface of the detection instrument, interfering with the accuracy of the measurement. And the relatively high temperature will also affect the service life of the equipment components and accelerate aging. Summary of the Utility Model

[0003] To solve the above problems, the utility model provides a chloride ion detection system, including:

[0004] A constant temperature box body, which is used to maintain the temperature of each device and pipeline in the box body within a set temperature range. The constant temperature box body is also provided with a liquid inlet and a liquid outlet, and the liquid inlet is connected to a first main pipeline;

[0005] An auxiliary thermostat, which is arranged in the constant temperature box body and is connected to the first main pipeline. The auxiliary thermostat is used to make the temperature of the urea solution to be measured match the temperature of the device and pipeline. The auxiliary thermostat is also provided with an exhaust valve;

[0006] A detection mechanism, which is connected to the auxiliary thermostat and is used to detect the chloride ion concentration in the urea solution.

[0007] Optionally, an inlet valve and a first pump are further arranged on the first main pipeline.

[0008] Optionally, a second main pipeline is further arranged in the constant temperature box body. One end of the second main pipeline is connected to the auxiliary thermostat, and the other end is connected to the detection mechanism. A second pump is further arranged on the second main pipeline.

[0009] Optionally, the detection mechanism includes:

[0010] A solution reservoir, which is connected to the second main pipeline, and the solution reservoir has a box-like structure with an accommodation cavity inside;

[0011] A reagent holding assembly for holding various reagents;

[0012] A second branch pipe, one end of which is connected to the solution reservoir and the other end is connected to the reagent holding assembly, and a third pump is also provided on the second branch pipe;

[0013] A spectrophotometer, which is connected to the solution reservoir and is used to detect the urea solution to be measured;

[0014] A fourth pump, which is arranged at one end of the spectrophotometer far from the connection with the solution reservoir, is connected to the spectrophotometer, and the fourth pump is connected to the liquid outlet.

[0015] Optionally, a cleaning mechanism is further provided on the first main pipeline, and the cleaning mechanism includes:

[0016] A filter, which is arranged on the first main pipeline near the liquid inlet;

[0017] A first branch pipe, which is arranged on the first main pipeline between the liquid inlet and the liquid inlet valve and is connected to the first main pipeline;

[0018] An exhaust valve, which is arranged on the first branch pipe, and by controlling the opening and closing of the exhaust valve, the flow state of the urea solution to be measured in the first branch pipe is adjusted.

[0019] Optionally, the reagent holding assembly includes a plurality of holding modules, and different reagents are placed in each holding module. Among them, the holding module includes:

[0020] A reagent bottle, which has a sealed cavity inside, and the reagent is placed in the sealed cavity;

[0021] A third branch pipe, one end of which is connected to the reagent bottle and the other end is connected to the second branch pipe;

[0022] A stop valve, which is arranged on the third branch pipe, and by controlling the opening and closing of the stop valve, the flow state of the reagent in the third branch pipe is adjusted.

[0023] Optionally, the number of the holding modules is five, which are respectively filled with nitric acid reagent, silver nitrate reagent, first calibration reagent, second calibration reagent, and ammonia water.

[0024] By adopting the above technical solution, the utility model mainly has the following technical effects:

[0025] By arranging a detection mechanism in the constant temperature box body, and detecting after the reagent in the reagent bottle in the detection mechanism reacts with the urea solution to be detected and then through a spectrophotometer, the technical problem that the detection result is affected by the high temperature of the urea solution is solved, the technical effect of accurately detecting the chloride ion concentration in the urea solution is realized, the accuracy and reliability of the detection result are ensured, and strong support is provided for the stable operation of the urea hydrolysis to ammonia process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a chloride ion detection system of the utility model.

[0027] Among them, the meanings of the reference numerals are as follows:

[0028] 1. Constant temperature box body; 11. First main pipeline; 111. Liquid inlet valve; 112. First pump; 113. Filter; 114. First branch pipe; 115. Discharge valve; 12. Second main pipeline; 121. Second pump;

[0029] 2. Auxiliary thermostat; 21. Drain valve;

[0030] 3. Detection mechanism; 31. Solution storage; 32. Reagent holding assembly; 321. Reagent bottle; 322. Third branch pipe; 323. Stop flow valve; 33. Second branch pipe; 331. Third pump; 34. Spectrophotometer; 35. Fourth pump; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the specification drawings in the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the utility model.

[0032] Referring to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the utility model. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0033] Please refer to Figure 1As shown in the figure, the present utility model provides a chloride ion detection system. In actual application, it is used to detect the chloride ion concentration in urea solution. It includes a constant temperature box body 1, an auxiliary thermostat 2 arranged in the constant temperature box body 1, and a detection mechanism 3 connected to the auxiliary thermostat 2.

[0034] Specifically, the constant temperature box body 1 is used to maintain the temperatures of various devices and pipelines in the box body within a set temperature range (25°C to 35°C) to reduce the temperature difference change of various devices and pipelines in the constant temperature box body 1. The constant temperature box body 1 is composed of an outer box body, an inner box body, an isolation layer, an air circulation system, a temperature control system, etc. For example, the isolation layer is arranged between the outer box body and the inner box body of the constant temperature box body 1 and is made of heat insulation materials such as polyurethane foaming agent to isolate the temperature inside the constant temperature box body 1 from the external temperature and enhance the heat preservation effect of the constant temperature box body 1. The constant temperature box body 1 is also provided with a liquid inlet and a liquid outlet, and the to-be-detected urea solution can enter the constant temperature box body 1 through the liquid inlet. It can be understood that the to-be-detected urea solution refers to the latest sampled urea solution sample that needs to be detected. Among them, the liquid inlet is communicated with a first main pipeline 11. After the to-be-detected urea solution enters the constant temperature box body 1, it circulates in the flow channel of the first main pipeline 11.

[0035] In this embodiment, since the temperature of the to-be-detected urea solution is usually between 40°C and 50°C when it flows into the constant temperature box body 1, and the temperatures of the devices and pipelines inside the constant temperature box body 1 are lower than the temperature of the to-be-detected urea solution. Therefore, after the to-be-detected urea solution enters the constant temperature box body 1, water mist will be generated on the wall surface of the detection mechanism, interfering with the measurement accuracy, and the higher temperature will also affect the service life of the equipment components and accelerate aging. To make the temperature of the to-be-detected urea solution adapt to that of the devices and pipelines, the bottom end of the auxiliary thermostat 2 is provided with a liquid inlet end and a liquid outlet end. The liquid inlet end of the auxiliary thermostat 2 is communicated with the first main pipeline 11. After the to-be-detected urea solution enters the auxiliary thermostat 2, it is cooled by the auxiliary thermostat 2 and the temperature after cooling of the to-be-detected urea solution is maintained. For example, the auxiliary thermostat 2 includes a cooling circulation structure, which circulates a cooling medium such as water, ethylene glycol aqueous solution or heat-conducting oil inside the equipment through its internal circulation components, so that the to-be-detected urea solution is cooled inside the auxiliary thermostat 2 and the temperature after cooling is maintained. A drain valve 21 is also arranged on the liquid outlet end of the auxiliary thermostat 2. Opening the drain valve 21 can drain the to-be-detected urea solution in the auxiliary thermostat 2.

[0036] An inlet valve 111 and a first pump 112 are further provided on the first main pipeline 11. By controlling the opening and closing of the inlet valve 111, the flow state of the urea solution to be measured in the first main pipeline 11 can be adjusted. For example, when the inlet valve 111 is in the open state, the urea solution to be measured can flow into the auxiliary thermostat 2 through the first main pipeline 11. When the inlet valve 111 is in the closed state, the urea solution to be measured can only flow in the first main pipeline 11 between the inlet of the constant temperature box body 1 and the inlet valve 111. The first pump 112 is used to provide power for the flow of the urea solution to be measured in the first main pipeline 11, so as to pump all the urea solution to be measured flowing into the first main pipeline 11 into the auxiliary thermostat 2 to prevent it from remaining in the first main pipeline 11. It can be understood that the pump mentioned in this application can be, but is not limited to, a centrifugal pump, and can also be a peristaltic pump. In this embodiment, a centrifugal pump is adopted, which is composed of components such as an impeller, a pump casing, and a shaft seal. Its working principle is that the impeller rotates at a high speed driven by an electric motor, a vacuum is formed at the inlet of the impeller, and the liquid flows along the suction pipeline under the action of atmospheric pressure, thereby promoting the flow of the urea solution to be measured in the pipeline.

[0037] In some preferred embodiments, to avoid the mixing of the solution remaining in the pipeline during the previous detection stage with the urea solution to be measured, thereby affecting the detection result, a cleaning mechanism is further provided on the first main pipeline 11. The cleaning mechanism includes a filter 113, a first branch pipe 114 connected to the first main pipeline 11, and a discharge valve 115 provided on the first branch pipe 114. Among them, the filter 113 is provided on the first main pipeline 11 near the inlet of the constant temperature box body 1 for filtering impurities in the urea solution to be measured. In some embodiments, the filter 113 can be, but is not limited to, a bag filter, and can also be a core filter or other filters with filtering functions. The first branch pipe 114 is provided on the first main pipeline 11 between the inlet and the inlet valve 111. One end of it is connected to the first main pipeline 11, and the other end penetrates through the bottom end of the constant temperature box body 1. When the inlet valve 111 is closed, the urea solution to be measured can flow out through the first branch pipe 114. By controlling the opening and closing of the discharge valve 115, the flow state of the urea solution to be measured in the first branch pipe 114 can be controlled. For example, when the discharge valve 115 is closed, the urea solution to be measured cannot flow in the first branch pipe 114. That is, after the urea solution to be measured flows into the first main pipeline 11, the inlet valve 111 is closed, the discharge valve 115 is opened, and under the flow action of the urea solution to be measured, the solution remaining in the first main pipeline 11 after the previous detection is carried out and discharged.

[0038] In this embodiment, a second main pipeline 12 is further arranged in the constant temperature box body 1. One end of the second main pipeline 12 is communicated with the liquid outlet end of the auxiliary thermostat 2. After the urea solution to be measured flows out of the auxiliary thermostat 2, it can flow in the second main pipeline 12. The other end of the second main pipeline 12 is communicated with the detection mechanism 3, that is, the detection mechanism 3 is communicated with the auxiliary thermostat 2 through the second main pipeline 12. The detection mechanism 3 is used to detect the chloride ion concentration in the urea solution. That is, after the urea solution to be measured flowing out of the auxiliary thermostat 2 flows into the detection mechanism 3 through the second main pipeline 12, detection is carried out. Moreover, a second pump 121 is further arranged on the second main pipeline 12. The second pump 121 is used to pump all the urea solution to be measured in the second main pipeline 12 into the detection mechanism 3 for detection, so as to prevent the urea solution to be measured from remaining in the second main pipeline 12.

[0039] In this embodiment, the detection mechanism 3 includes a solution storage 31, a spectrophotometer 34 connected to the solution storage 31, and a second branch pipe 33, and a reagent holding assembly 32 connected to the second branch pipe 33. Specifically, the solution storage 31 is communicated with the second main pipeline 12. The solution storage 31 has a box-shaped structure with a cavity inside. The cavity is a containing cavity. The solution storage 31 is used to store the urea solution to be measured. The reagent holding assembly 32 is used to hold various reagents. One end of the second branch pipe 33 is communicated with the solution storage 31, and the other end is communicated with the reagent holding assembly 32. Various reagents in the reagent holding assembly 32 can flow into the solution storage 31 through the second branch pipe 33. Among them, a third pump 331 is further arranged on the second branch pipe 33, which is used to pump various reagents in the reagent module into the solution storage 31 to be mixed with the urea solution to be measured. The spectrophotometer 34 is communicated with the solution storage 31. When the reaction between the reagents in the reagent holding module and the urea solution to be measured in the solution storage 31 is stable, the urea solution to be measured is detected by the spectrophotometer 34. For example, the spectrophotometer 34 is composed of a light source, a monochromator, a cuvette, a detector, a data processing system, etc. The spectrophotometer 34 measures the absorption degree of a substance to light of a specific wavelength to quantitatively analyze the type and concentration of the substance, so as to measure the chloride ion concentration in the urea solution to be measured. A fourth pump 35 is further arranged at one end of the spectrophotometer 34 away from the connection with the solution storage 31. The fourth pump 35 is communicated with the spectrophotometer 34. The fourth pump 35 is used to pump and discharge the urea solution in the spectrophotometer 34. The liquid outlet end of the fourth pump 35 is communicated with the liquid outlet of the constant temperature box body 1. The urea solution pumped by the fourth pump 35 is discharged through the liquid outlet of the constant temperature box body 1.

[0040] More specifically, the reagent storage assembly 32 includes a number of storage modules, and different reagents are placed in each storage module. In this embodiment, for the convenience of describing the storage module, one storage module will be described herein. The storage module includes a reagent bottle 321, a third branch pipe 322 connected to the reagent bottle 321, and a stop valve 323 provided on the third branch pipe 322. Specifically, a sealed cavity is provided inside the reagent bottle 321, and the reagent is placed in the sealed cavity to prevent the reagent from deteriorating. One end of the third branch pipe 322 is communicated with the sealed cavity inside the reagent bottle 321, and the other end is communicated with the second branch pipe 33. The reagent in the reagent bottle 321 can be pumped by the third pump 331, so that the reagent in the reagent bottle 321 flows into the second branch pipe 33 through the third branch pipe 322, and then flows into the solution storage tank 31 to react with the urea solution to be measured. The stop valve 323 is provided on the third branch pipe 322 and is used to control the flow state of the reagent in the reagent bottle 321. For example, when one of the stop valves 323 is opened and the remaining stop valves 323 are kept closed, the reagent in the corresponding reagent bottle 321 can flow into the solution storage tank 31, while the reagents in the remaining reagent bottles 321 will not flow, and it is prevented that the flowing reagent solution flows into other reagent bottles 321 when flowing in the second branch pipe 33.

[0041] In some preferred embodiments, the number of the storage modules is five, which are respectively filled with nitric acid reagent, silver nitrate reagent, first calibration reagent, second calibration reagent, and ammonia water. Specifically, after the solution to be measured flows into the solution storage tank 31, nitric acid solution is introduced to adjust the pH of the solution to be measured to about 1. After the reaction is stable, it is detected by the spectrophotometer 34 to obtain the measurement zero value; then silver nitrate solution is introduced into the solution storage tank 31. After the reaction is stable, it is detected by the spectrophotometer 34. After obtaining the chloride ion concentration value, the solution in the spectrophotometer 34 is discharged by the fourth pump 35.

[0042] Since the spectrophotometer 34 needs to generate a specific working curve, therefore, a two-point calibration method needs to be adopted, that is, the absorbances corresponding to two concentrations are measured, and the device can generate a working curve, and then the concentration can be obtained by measuring the absorbance of the solution to be measured. Therefore, by introducing the first calibration reagent into the solution storage tank 31 and detecting it by the spectrophotometer 34 to obtain the measurement zero value, then transporting the silver nitrate solution to the solution storage tank 31. After the reaction is stable, it is detected by the spectrophotometer 34 to complete the first-point calibration; then introducing the second calibration reagent into the solution storage tank 31 to obtain the measurement zero value, then transporting the silver nitrate solution to the solution storage tank 31. After the reaction is stable, it is detected by the spectrophotometer 34 to complete the second-point calibration.

[0043] To prevent fouling on the inner surface of the pipeline, it is necessary to clean the pipeline and the instrument after the detection. Since ammonia water can react with silver chloride to form water-soluble dichloroargentate ammonia, after the detection, ammonia water is introduced into the solution storage tank 31. After the reaction stabilizes, the reacted mixed solution is pumped out through the fourth pump 35.

[0044] In this embodiment, by setting the detection mechanism 3 in the constant temperature box body 1, and detecting after the reagent in the reagent bottle 321 in the detection mechanism 3 reacts with the urea solution to be detected through the spectrophotometer 34, the technical problem that the detection result of the urea solution is affected by the high temperature is solved, the technical effect of accurately detecting the chloride ion concentration in the urea solution is achieved, the accuracy and reliability of the detection result are ensured, and strong support is provided for the stable operation of the urea hydrolysis to ammonia process.

[0045] Finally, it should be noted that: what is disclosed in the embodiments of the present utility model is only the preferred embodiments of the present utility model, which are only used to illustrate the technical solutions of the present utility model, rather than to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A chloride ion detection system, characterized in that: include: A constant temperature box (1), the constant temperature box (1) being used to maintain the temperature of various devices and pipelines in the box, the constant temperature box (1) being further provided with a liquid inlet and a liquid outlet, the liquid inlet being connected to a first main pipeline (11); an auxiliary thermostat (2), the auxiliary thermostat (2) being arranged in the thermostatic box (1), the auxiliary thermostat (2) being connected to the first main pipe (11), the auxiliary thermostat (2) being used to adjust and maintain the temperature of the urea solution to be tested, and the auxiliary thermostat (2) being further provided with a drain valve (21); A detection mechanism (3), the detection mechanism (3) is connected to the auxiliary thermostat (2) and is used to detect the chloride ion concentration in the urea solution.

2. A chloride ion detection system according to claim 1, characterized in that: The first main pipeline (11) is also provided with a liquid inlet valve (111) and a first pump (112).

3. A chloride ion detection system according to claim 1, characterized in that: A second main pipe (12) is also provided in the thermostatic box (1), one end of which is connected to the auxiliary thermostat (2) and the other end of which is connected to the detection mechanism (3). A second pump (121) is also provided on the second main pipe (12).

4. A chloride ion detection system according to claim 3, characterized in that: The detection mechanism (3) comprises: A solution storage device (31), the solution storage device (31) being in communication with the second main pipeline (12), the solution storage device (31) being a box-shaped structure with a containing cavity arranged therein; A reagent holding component (32), wherein the reagent holding component (32) is used to hold the reagent; a second branch pipe (33), one end of the second branch pipe (33) being connected to the solution storage device (31), and the other end of the second branch pipe (33) being connected to the reagent containing assembly (32), and a third pump (331) being further provided on the second branch pipe (33); A spectrophotometer (34), the spectrophotometer (34) being connected to the solution storage device (31), and the spectrophotometer (34) being used to detect the chloride ion concentration of the urea solution to be tested; A fourth pump (35), the fourth pump (35) is arranged at an end of the spectrophotometer (34) away from the end connected to the solution storage device (31), and is connected to the spectrophotometer (34), and the fourth pump (35) is connected to the liquid outlet of the constant temperature box (1).

5. A chloride ion detection system according to claim 2, characterized in that: The first main pipe (11) is also provided with a cleaning mechanism, the cleaning mechanism comprising: A filter (113), the filter (113) being arranged on the first main pipe (11) near the liquid inlet; a first branch pipe (114), the first branch pipe (114) being arranged on the first main pipe (11) between the liquid inlet and the liquid inlet valve (111), and being in communication with the first main pipe (11); A discharge valve (115) is provided on the first branch pipe (114), and the flow state of the urea solution to be tested in the first branch pipe (114) is adjusted by controlling the switch of the discharge valve (115).

6. A chloride ion detection system according to claim 4, characterized in that: The reagent containing assembly (32) comprises a plurality of containing modules, each containing module is provided with different reagents, wherein the containing module comprises: A reagent bottle (321), wherein a sealed cavity is provided in the reagent bottle (321), and the reagent is placed in the sealed cavity; a third branch pipe (322), one end of the third branch pipe (322) being connected to the reagent bottle (321), and the other end of the third branch pipe (322) being connected to the second branch pipe (33); A stop valve (323), the stop valve (323) is arranged on the third branch pipe (322), and the flow state of the reagent in the third branch pipe (322) is adjusted by controlling the switch of the stop valve (323).

7. A chloride ion detection system according to claim 6, characterized in that: The number of the containing modules is five, and they are respectively filled with nitric acid reagent, silver nitrate reagent, first calibration reagent, second calibration reagent, and ammonia water.

Images