Online chloride ion concentration detector for urea hydrolysis reactor

Abstract

The utility model discloses a chloride ion concentration on-line detector for a urea hydrolysis reactor. The chloride ion concentration on-line detector consists of a detector shell, the lower layer is provided with a dilution water tank and a mixing tank with a weight sensor, the upper layer is provided with a urea solution hydrolyzer sewage discharge automatic valve, a radiator, a peristaltic pump, a three-way automatic valve, a circulating groove, a demineralized water automatic valve I and a demineralized water automatic valve II, the radiator is arranged at the front end of the mixing tank, and the front end of the radiator is connected with the urea solution hydrolyzer sewage discharge automatic valve; a peristaltic pump is arranged between the mixing tank and the dilution water tank, a three-way automatic valve is arranged between the peristaltic pump and the dilution water tank, the other end of the three-way automatic valve is connected with a circulation groove, and a radiator is located between the second desalted water automatic valve and the mixing tank. An electrode type chloride ion concentration detector is arranged in the circulating groove; the PLC control system controls opening or closing of the urea solution hydrolyzer sewage discharge automatic valve, the radiator, the first demineralized water automatic valve, the three-way automatic valve, the peristaltic pump and the second demineralized water automatic valve.

Description

Technical Field

[0001] This utility model relates to the field of denitrification technology in environmental protection, and in particular to an online chloride ion concentration detector for urea hydrolysis reactors. Background Technology

[0002] Urea hydrolysis ammonia production technology is widely used in flue gas denitrification projects due to its simple process, high urea utilization rate, and easy construction. The technology involves heating a 40-50% urea solution with steam or electricity, causing a hydrolysis reaction in a urea hydrolysis reactor at a pressure of approximately 0.4-0.6 MPa and a temperature of approximately 140-160°C. This produces a mixture of ammonia, carbon dioxide, and water vapor. This mixture is then metered and distributed, diluted with hot dilution air in an ammonia-air mixer, and finally enters the flue gas mixing system to remove NOx from the flue gas.

[0003] Because urea solution is continuously added to the reactor, the chloride ions mixed in with the urea solution are non-decomposable and will continuously concentrate within the hydrolyzer, causing excessive chloride ion levels. This not only forms crystals on the heating coils within the hydrolyzer, affecting its heat exchange efficiency, but more seriously, the large amount of chloride ions will cause intergranular corrosion, stress corrosion cracking, and uniform corrosion in the 316L stainless steel urea hydrolysis reactor, severely impacting the service life of the reactor and its components. In extreme cases, it may even cause leaks in the urea hydrolysis reactor, creating safety hazards. Therefore, it is necessary to strictly control the chloride ion concentration within the urea hydrolysis reactor.

[0004] Therefore, it is necessary to regularly monitor the chloride ion content in the effluent from the hydrolysis reactor weekly, and discharge the wastewater promptly if the chloride ion content exceeds the standard. Currently, most methods for determining chloride ions involve sampling the effluent from the hydrolysis reactor and then performing experimental measurements in the laboratory using the silver nitrate titration molar method or ion chromatography. Because the effluent from the hydrolysis reactor contains urea solution and ammonia, these two methods are relatively cumbersome, and the sampling process is also quite dangerous. Furthermore, due to the high temperature of the effluent from the urea hydrolysis reactor, sampling requires heat tracing, which can easily lead to large fluctuations in the results and low reliability.

[0005] To address the aforementioned problems, this utility model is hereby proposed. Utility Model Content

[0006] The purpose of this invention is to provide an online chloride ion concentration detector for urea hydrolysis reactors.

[0007] The objective of this utility model can be achieved through the following technical solutions:

[0008] An online chloride ion concentration detector for a urea hydrolysis reactor comprises a detector housing. The housing has two layers: the upper cavity houses a PLC control system with a control display screen, and the lower cavity houses a sampling and measurement system. The lower cavity is further divided into two layers: the lower layer contains a dilution water tank and a mixing tank with a weight sensor; the upper layer contains an automatic urea solution hydrolyzer wastewater discharge valve, a radiator, a peristaltic pump, a three-way automatic valve, a flow channel, and two automatic demineralized water valves. A radiator is installed at the front end of the mixing tank, and the front end of the radiator is connected to the urea solution hydrolyzer. Automatic wastewater discharge valve; a peristaltic pump is installed between the mixing tank and the dilution water tank, and a three-way automatic valve is installed between the peristaltic pump and the dilution water tank. The other end of the three-way automatic valve is connected to a flow channel. The dilution water tank is connected to the demineralized water supply source through demineralized water automatic valve one, and the mixing tank is connected to the demineralized water supply source through demineralized water automatic valve two. The radiator is located between demineralized water automatic valve two and the mixing tank; an electrode-type chloride ion concentration detector is installed in the flow channel; the PLC control system controls the opening or closing of the urea solution hydrolyzer wastewater discharge valve, radiator, demineralized water automatic valve one, three-way automatic valve, peristaltic pump, and demineralized water automatic valve two.

[0009] Preferably, the front of the upper cavity is a display screen, the rear of the upper cavity is provided with a lockable door, and the interior of the upper cavity is equipped with a PLC control system and a power interface.

[0010] Furthermore, the lower cavity is provided with a lockable door on the front.

[0011] Preferably, a drain outlet is provided below the flow channel.

[0012] Furthermore, the lower sidewall of the lower cavity is provided with a demineralized water inlet valve, a hose, a urea solution hydrolyzer drain inlet valve, and a stainless steel sampling tube; the urea solution hydrolyzer wastewater automatic valve is connected to the urea solution hydrolyzer wastewater supply source through the stainless steel sampling tube.

[0013] The demineralized water inlet valve is located on the hose, which is connected to the demineralized water supply source. The hose is connected to the demineralized water automatic valve one and the demineralized water automatic valve two respectively. The urea solution hydrolyzer drain inlet valve 16 is located on the stainless steel sampling tube.

[0014] Beneficial technical effects:

[0015] This utility model, by setting up a dilution water tank, a mixing tank, an automatic wastewater discharge valve for the urea solution hydrolyzer, a peristaltic pump, a three-way automatic valve, a demineralized water automatic valve one, and a demineralized water automatic valve two, can automatically and in real time measure the chloride ions inside the urea hydrolysis reactor. It is simple to use, provides reliable measurement results, saves manpower, and the system is simple, easy to operate, and convenient to maintain. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the housing structure of the detector of this utility model.

[0018] Figure 2 This is a schematic diagram of the principle of this utility model. Detailed Implementation

[0019] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0020] like Figure 1-Figure 2 As shown, an online chloride ion concentration detector for a urea hydrolysis reactor comprises a detector housing 12. The detector housing 12 is divided into two layers: the upper cavity houses a PLC control system 13 with a control display screen, and the lower cavity houses a sampling and measurement system 14. The display screen is located on the front of the upper cavity, and a lockable door is located at the rear of the upper cavity. The PLC control system 13 and a power interface are located inside the upper cavity.

[0021] The lower chamber has a lockable door on the front. The interior of the lower chamber is divided into two layers: the lower layer of the lower chamber contains a dilution water tank 7 and a mixing tank 4 with a weight sensor, and the upper layer of the lower chamber contains an automatic drain valve 2 for urea solution hydrolyzer, a radiator 3, a peristaltic pump 5, a three-way automatic valve 6, a flow channel 8, an automatic demineralized water valve 10, and an automatic demineralized water valve 21. The front end of the mixing tank 4 is equipped with a radiator 3, and the front end of the radiator 3 is connected to the automatic drain valve 2 for urea solution hydrolyzer. The urea solution hydrolyzer wastewater discharge valve 2 is connected to the urea solution hydrolyzer wastewater supply source. A peristaltic pump 5 is installed between the mixing tank 4 and the dilution water tank 7. A three-way automatic valve 6 is installed between the peristaltic pump 5 and the dilution water tank 7. The other end of the three-way automatic valve 6 is connected to the flow channel 8. The dilution water tank 7 is connected to the demineralized water supply source through the demineralized water automatic valve one 10. The mixing tank 4 is connected to the demineralized water supply source through the demineralized water automatic valve two 11. The radiator 3 is located between the demineralized water automatic valve two 11 and the mixing tank 4.

[0022] A drain outlet 17 is provided at the bottom of the flow channel 8, and the wastewater from the urea solution hydrolyzer in the flow channel 8 is discharged through the drain outlet 17.

[0023] The lower side wall of the lower chamber is equipped with a demineralized water inlet valve 15, a hose 9, a urea solution hydrolyzer drain inlet valve 16, and a stainless steel sampling tube 1. The urea solution hydrolyzer wastewater automatic valve 2 is connected to the urea solution hydrolyzer wastewater supply source through the stainless steel sampling tube 1.

[0024] The demineralized water inlet valve 15 is located on the hose 9, which is connected to the demineralized water supply source. The hose 9 is connected to the demineralized water automatic valve 10 and the demineralized water automatic valve 11 respectively. The urea solution hydrolyzer drain inlet valve 16 is located on the stainless steel sampling tube 1.

[0025] The process of online automatic measurement of chloride ion concentration in the online chloride ion concentration detector used in urea hydrolysis reactor is as follows:

[0026] The PLC control system 13 with a control display screen controls the automatic valve 2 and radiator 3 of the urea solution hydrolyzer to open. After the urea solution hydrolyzer is cooled down, the wastewater from the urea solution hydrolyzer enters the mixing tank 4 with a weight sensor. After the weight sensor displays 100g, the PLC control system 13 with a control display screen controls the automatic valve 2 and radiator 3 of the urea solution hydrolyzer to close.

[0027] The PLC control system 13 with a control display screen controls the automatic demineralized water valve 10 to open, injecting demineralized water into the dilution tank 7. Once the liquid level meets the requirements, the PLC control system 13 with a control display screen controls the automatic demineralized water valve 10 to close.

[0028] The PLC control system 13 with a control display screen controls the three-way automatic valve 6 to open, and the peristaltic pump 5 pumps the demineralized water from the dilution tank 7 into the mixing tank 4 with a weight sensor. After the weight sensor displays 1000g,

[0029] The PLC control system 13 with a control display screen controls the three-way automatic valve 6 to turn and the peristaltic pump 5 to reverse, pumping the diluted urea solution / hydrolyzer wastewater into the flow tank 8.

[0030] An electrode-type chloride ion concentration detector is installed in the flow tank 8. The electrode-type chloride ion concentration detector detects the urea solution / hydrolyzer wastewater after dilution in the flow tank 8. After multiple detections, the average value is taken and calculated to obtain the final chloride ion concentration in the urea solution / hydrolyzer wastewater. The value is displayed on the display screen of the PLC control system 13 with a control display screen, and the data can be transmitted to the DSC display.

[0031] After the test is completed, the urea solution / hydrolyzer wastewater in the flow channel 8 is discharged from the drain outlet 17.

[0032] The pipelines and containers containing urea solution / hydrolyzer wastewater are flushed. The PLC control system 13 with display screen controls the automatic demineralized water valve 11 to open. The demineralized water enters the mixing tank 4 with a weight sensor. After the weight sensor displays 1000g, the automatic demineralized water valve 11 closes. The solution is then pumped into the flow channel 8 by the peristaltic pump 5 and discharged from the drain outlet.

[0033] During the second rinsing, the PLC control system 13 with a display screen controls the automatic demineralized water valve 11 to open, and the demineralized water enters the mixing tank 4 with a weight sensor. After the weight sensor displays 1000g, the automatic demineralized water valve 11 closes, and the solution is pumped into the flow channel 8 by the peristaltic pump 5 and then discharged from the drain port.

[0034] Through the above operations, a complete chloride ion concentration detection is completed. The entire process is automatically controlled by the PLC control system 13 with a display screen, requiring no manual operation, making it simple to use, providing reliable measurement results, and saving manpower.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An online chloride ion concentration detector for a urea hydrolysis reactor, characterized in that, The instrument consists of a housing; the housing is divided into two layers. The upper cavity houses the PLC control system with a control display screen, and the lower cavity houses the sampling and measurement system. The lower cavity's internal chamber is further divided into upper and lower layers: the lower layer contains a dilution water tank and a mixing tank with a weight sensor; the upper layer contains an automatic drain valve for the urea solution hydrolyzer, a radiator, a peristaltic pump, a three-way automatic valve, a flow channel, and two automatic demineralized water valves. A radiator is installed at the front end of the mixing tank, and the front end of the radiator is connected to the automatic drain valve for the urea solution hydrolyzer. A peristaltic pump is installed between the dilution water tanks, and a three-way automatic valve is installed between the peristaltic pump and the dilution water tanks. The other end of the three-way automatic valve is connected to a flow channel. The dilution water tank is connected to the demineralized water supply source through demineralized water automatic valve one, and the mixing tank is connected to the demineralized water supply source through demineralized water automatic valve two. The radiator is located between demineralized water automatic valve two and the mixing tank. An electrode-type chloride ion concentration detector is installed in the flow channel. The PLC control system controls the opening and closing of the urea solution hydrolyzer wastewater discharge automatic valve, the radiator, demineralized water automatic valve one, the three-way automatic valve, the peristaltic pump, and demineralized water automatic valve two.

2. The online chloride ion concentration detector for a urea hydrolysis reactor according to claim 1, characterized in that, The upper cavity has a display screen on the front and a lockable door at the back. The upper cavity also contains a PLC control system and a power interface.

3. The online chloride ion concentration detector for a urea hydrolysis reactor according to claim 2, characterized in that, The lower cavity is equipped with a lockable door on the front.

4. The online chloride ion concentration detector for a urea hydrolysis reactor according to claim 3, characterized in that, A drain outlet is provided below the flow channel.

5. The online chloride ion concentration detector for a urea hydrolysis reactor according to claim 2, characterized in that, The lower sidewall of the lower cavity is equipped with a demineralized water inlet valve, a hose, a urea solution hydrolyzer drain inlet valve, and a stainless steel sampling tube; the urea solution hydrolyzer wastewater automatic valve is connected to the urea solution hydrolyzer wastewater supply source through the stainless steel sampling tube. The demineralized water inlet valve is located on the hose, which is connected to the demineralized water supply source. The hose is connected to the demineralized water automatic valve one and the demineralized water automatic valve two respectively. The urea solution hydrolyzer drain inlet valve 16 is located on the stainless steel sampling tube.

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