Automatic detection system for pH value and concentration of ammonium nitrate solution

Abstract

The invention relates to the technical field of chemical detection, and discloses an automatic detection system for the pH value and concentration of an ammonium nitrate solution. The dilution module comprises a mixing tank, and the mixing tank is connected with the sampling valve through a pipeline; the input end of the condenser is connected with the mixing tank through a pipeline, and the condenser is used for cooling the diluent; the pH detection module comprises a cooling tank, the cooling tank is connected with the output end of the condenser through a pipeline, and a pH sensor is arranged in the cooling tank; through dilution and cooling treatment, the concentration and temperature of the ammonium nitrate solution are reduced, the service life of the sensor is prolonged, and the measurement precision is improved. The concentration detection module is used for detecting the concentration of the diluent based on a non-contact electromagnetic wave spectrum analysis method; the concentration is detected by adopting an electromagnetic wave spectrum analysis method, and interference and potential safety hazards of a traditional method are avoided. The real-time, continuous and automatic detection of the pH value and the concentration value of the ammonium nitrate solution is realized, and the production safety is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical detection, in particular to an automatic detection system for pH value and concentration of ammonium nitrate solution. Background Art

[0002] Ammonium nitrate is an important chemical raw material, widely used in fertilizers, explosives and other fields. In the production process, the pH value and concentration of ammonium nitrate solution are key process indicators, directly affecting product quality and production safety. However, the existing technology has the following problems: 1. Limitations of traditional manual testing: It relies on manual sampling and laboratory analysis, which is complex, time-consuming, and prone to large errors. In addition, manual operation in high-temperature and highly corrosive environments poses safety risks.

[0003] 2. Existing online detection technologies are insufficient: pH detection: Direct contact sensors are susceptible to corrosion from ammonium nitrate solutions, resulting in a short service life and high maintenance costs; Concentration detection: Ultrasonic and nuclear radiation source methods have significant interference and low safety. Therefore, there is an urgent need for an efficient, accurate, and interference-resistant automatic detection system for the pH value and concentration of ammonium nitrate solution. Summary of the Invention

[0004] The object of the present invention is to provide an automatic detection system for the pH value and concentration of an ammonium nitrate solution to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: an automatic detection system for the pH value and concentration of ammonium nitrate solution, comprising: An online sampling module includes a sampling valve connected to the neutralization flash tank through a pipeline and used to extract ammonium nitrate solution from the neutralization flash tank; The dilution module includes a mixing tank connected to the sampling pump through a pipeline and used to mix the sampled ammonium nitrate solution with desalted water to form a dilution solution; Condenser: the input end of the condenser is connected to the mixing tank through a pipeline, and the condenser is used to cool the dilution liquid; A pH detection module includes a cooling tank connected to the condenser output via a pipeline. A pH sensor is provided in the cooling tank for detecting the pH value of the ammonium nitrate dilution solution after cooling in the cooling tank. The concentration detection module detects the concentration of ammonium nitrate solution based on non-contact electromagnetic wave spectrum analysis.

[0006] Wherein, a filter is provided on the pipeline between the sampling valve and the neutralization flash tank for removing solid particle impurities in the ammonium nitrate solution.

[0007] Wherein, a temperature sensor is provided in the mixing tank, and the temperature sensor is used to monitor the temperature of the diluent in real time.

[0008] The mixing tank is connected to an external desalted water storage tank through a pipeline, and a first ball valve is provided on the pipeline between the mixing tank and the desalted water storage tank.

[0009] Wherein, a second ball valve is provided on the pipeline between the condenser and the cooling tank.

[0010] Wherein, when the ammonium nitrate solution is mixed with the desalted water to form a dilution solution, the ammonium nitrate solution and the desalted water are mixed in a mass ratio of 1:9 to form a 10% dilution solution.

[0011] Wherein, a waveguide probe is provided on the intermediate tank circulation pipeline, and the waveguide probe is used to transmit electromagnetic waves to the ammonium nitrate solution and receive reflected signals.

[0012] Among them, the specific method for detecting the concentration of ammonium nitrate solution based on non-contact electromagnetic wave spectrum analysis is: Step 1: Multi-band scanning: The waveguide probe transmits electromagnetic waves at a frequency of 1 GHz to 100 GHz, covering the characteristic absorption peak of the ammonium nitrate solution; Step 2: Transmission / reflection detection: Transmission mode: electromagnetic waves penetrate the ammonium nitrate solution, and the receiving end detects the attenuation of the transmitted light; Reflection mode: detects the phase change of the reflected wave on the solution surface; Step 3: Signal amplification and filtering: The preamplifier enhances weak signals and the digital filter removes noise; Step 4: Absorption spectrum analysis: Perform Fourier transform on the collected electromagnetic wave signal to extract the characteristic absorption peak intensity; Step 5: Concentration fitting: Based on the Lambert-Beer law, the concentration value is calculated to obtain the concentration of the ammonium nitrate solution.

[0013] It also includes: an abnormality detection module, if the pH value of the ammonium nitrate dilution exceeds the preset range, when the pH value is <1.5, an alarm is triggered; when the pH value is <1, the interlock stops.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention reduces the concentration and temperature of the ammonium nitrate solution through dilution and cooling treatment, thereby extending the service life of the sensor and improving detection accuracy. It adopts electromagnetic wave spectrum analysis to detect concentration, avoiding the interference and safety hazards of traditional methods, and realizes real-time, continuous and automated detection of ammonium nitrate solution to ensure production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is a control block diagram of an automatic detection system for pH value and concentration of ammonium nitrate solution according to the present invention; Figure 2 The present invention is a flow chart of a method for detecting the concentration of ammonium nitrate solution based on a non-contact electromagnetic wave spectrum analysis method.

[0016] In the figure, 1. Neutralization flash tank; 2. Sampling valve; 3. Mixing tank; 4. Condenser; 5. Cooling tank; 6. pH sensor. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] See also Figure 1-2 The present invention provides a technical solution: an automatic detection system for the pH value and concentration of ammonium nitrate solution, comprising: An online sampling module includes a sampling pump 2, which is connected to the neutralization flash tank 1 through a pipeline and is used to extract ammonium nitrate solution from the neutralization flash tank 1; The dilution module includes a mixing tank 3, which is connected to the sampling pump 2 through a pipeline and is used to mix the sampled ammonium nitrate solution with desalted water to form a dilution solution; Condenser 4, the input end of condenser 4 is connected to mixing tank 3 through a pipeline, and condenser 4 is used to cool the dilution liquid; A pH detection module includes a cooling tank 5 connected to the output end of the condenser 4 via a pipeline. A pH sensor 6 is provided in the cooling tank 5. The pH sensor 6 is used to detect the pH value of the cooled ammonium nitrate dilution in the cooling tank 5. The dilution and cooling process reduces the concentration and temperature of the ammonium nitrate solution, thereby extending the life of the pH sensor 6. The concentration detection module detects the concentration of ammonium nitrate solution based on non-contact electromagnetic wave spectrum analysis, using electromagnetic wave spectrum analysis to detect concentration, avoiding the interference and safety hazards of traditional methods.

[0019] Wherein, a filter is provided on the pipeline between the sampling pump 2 and the neutralization flash tank 1 for removing solid particle impurities in the ammonium nitrate solution.

[0020] Among them, a temperature sensor is provided in the mixing tank 3, and the temperature sensor is used to monitor the temperature of the diluent in real time. The temperature threshold in the mixing tank 3 is set at 60±5°C, and the temperature of the diluent is monitored in real time by the temperature sensor.

[0021] The mixing tank 3 is connected to an external desalted water storage tank through a pipeline. A first electric ball valve is provided on the pipeline between the mixing tank 3 and the desalted water storage tank to control the speed at which the desalted water flows into the mixing tank 3 .

[0022] A second ball valve is provided on the pipeline between the condenser 4 and the cooling tank 5 , and the speed at which the diluent flowing out of the condenser 4 flows into the cooling tank 5 is controlled by the second ball valve.

[0023] Wherein, when the ammonium nitrate solution is mixed with the desalted water to form a dilution solution, the ammonium nitrate solution and the desalted water are mixed in a mass ratio of 1:9 to form a 10% dilution solution.

[0024] Among them, a waveguide probe is provided on the circulation pipe of the middle tank, and the waveguide probe is used to transmit electromagnetic waves to the ammonium nitrate solution and receive reflected signals.

[0025] Among them, the specific method for detecting ammonium nitrate solution based on non-contact electromagnetic wave spectrum analysis is: Step 1: Multi-band scanning: The waveguide probe transmits electromagnetic waves at a frequency of 1 GHz to 100 GHz, covering the characteristic absorption peak of the ammonium nitrate solution; Step 2: Transmission / reflection detection: Transmission mode: electromagnetic waves penetrate the ammonium nitrate solution, and the receiving end detects the attenuation of the transmitted light; Reflection mode: detects the phase change of the reflected wave on the solution surface; Step 3: Signal amplification and filtering: The preamplifier enhances weak signals and the digital filter removes noise; Step 4: Absorption spectrum analysis: Perform Fourier transform on the collected electromagnetic wave signal to extract the characteristic absorption peak intensity; Step 5: Concentration fitting: Based on the Lambert-Beer law, the concentration value is calculated to obtain the concentration of the ammonium nitrate solution.

[0026] It also includes: an abnormality detection module, if the pH value of the ammonium nitrate dilution exceeds the preset range, when the pH value is <1.5, an alarm is triggered; when the pH value is <1, the interlock stops.

[0027] The Fourier transform is a mathematical tool used to convert time-domain signals into frequency-domain signals, thereby analyzing the distribution of signals at different frequency components. In electromagnetic absorption spectroscopy, solutions selectively absorb electromagnetic waves of specific frequencies, resulting in attenuation of signal intensity. The Fourier transform can be used to: 1. Separate noise from valid signals: filter out high-frequency noise and low-frequency drift; 2. Identify characteristic absorption peaks: the absorption intensity of the extraction solution to electromagnetic waves of a specific frequency (corresponding to chemical bond vibration or molecular rotation frequency); 3. Calculate the absorption coefficient: Calculate the solution concentration using the Lambert-Beer law (A=εcl).

[0028] The specific method of performing Fourier transform on the collected electromagnetic wave signal and extracting the characteristic absorption peak intensity is as follows: Data acquisition: Use waveguide probe (electromagnetic wave sensor) to collect transmission / reflection signals, sampling frequency The Nyquist criterion must be met (at least twice the highest characteristic frequency), and the time domain signal S(t) must be recorded, where t is time and S(t) is the electromagnetic wave intensity (voltage or power). Denoising: removes high-frequency noise, eliminates DC offset and low-frequency drift, scales the signal amplitude to the [0,1] range, and improves Fourier transform stability; Fast Fourier transform calculation: Discrete Fourier transform formula: ; is the discretized time domain signal (number of sampling points N); is the frequency domain signal, k is the frequency index (corresponding to frequency ).

[0029] Identify characteristic absorption peaks: Determine the characteristic absorption frequency of ammonium nitrate solution (e.g. the stretching vibration frequency of NH4⁺ is about 1-10 GHz); find the peak of the corresponding frequency range in the spectrum (e.g. ); Calculate the absorption peak intensity A: ; Concentration calculation (Lambert-Beer law): A=εcl A is the absorption intensity (calculated by Fourier transform); ε is the molar absorptivity (calibrated by standard solution); c is the solution concentration (to be measured); l is the optical path length (the distance between the sensor and the solution); The final concentration is: .

[0030] Specifically, when the waveguide probe is a 24 GHz millimeter wave radar with a sampling rate of 100 MHz; The number of sampling points of Fourier transform is N=1024, the window function is Hanning window, and the frequency resolution is about 97.7 kHz; Characteristic peak: NH4⁺ absorption peak is located at 3.5 GHz, absorption intensity A=0.8; Concentration calculation: calibrated to ε = 0.5 L\cdotpmol −1 ⋅cm −1If the optical path length is 1 cm, the concentration is: ; Approximately equal to 20% ammonium nitrate solution.

[0031] At the same time, the concentration of the ammonium nitrate solution exceeded the preset range, with a concentration >93%, triggering an alarm to alert staff.

[0032] In summary, this application reduces the concentration and temperature of ammonium nitrate solution through dilution and cooling treatment, thereby extending the service life of the sensor and improving detection accuracy; uses electromagnetic wave spectrum analysis to detect concentration, avoiding the interference and safety hazards of traditional methods, and realizing real-time, continuous and automated detection of ammonium nitrate solution to ensure production safety.

[0033] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An automatic detection system for pH value and concentration of ammonium nitrate solution, characterized in that: include: An online sampling module includes a sampling valve connected to the neutralization flash tank through a pipeline and used to extract ammonium nitrate solution from the neutralization flash tank; The dilution module includes a mixing tank connected to the sampling pump through a pipeline and used to mix the sampled ammonium nitrate solution with desalted water to form a dilution solution; Condenser: the input end of the condenser is connected to the mixing tank through a pipeline, and the condenser is used to cool the dilution liquid; A pH detection module includes a cooling tank connected to the condenser output via a pipeline. A pH sensor is provided in the cooling tank for detecting the pH value of the ammonium nitrate dilution solution after cooling in the cooling tank. The concentration detection module detects the concentration of the dilution liquid based on non-contact electromagnetic wave spectrum analysis.

2. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: A filter is provided on the pipeline between the sampling valve and the neutralization flash tank for removing solid particle impurities in the ammonium nitrate solution.

3. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: A temperature sensor is provided in the mixing tank, and the temperature sensor is used to monitor the temperature of the diluent in real time.

4. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: The mixing tank is connected to an external desalted water storage tank through a pipeline, and a first ball valve is provided on the pipeline between the mixing tank and the desalted water storage tank.

5. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: A second ball valve is provided on the pipeline between the condenser and the cooling tank.

6. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: When the ammonium nitrate solution is mixed with the desalted water to form a dilution solution, the ammonium nitrate solution and the desalted water are mixed in a mass ratio of 1:9 to form a 10% dilution solution.

7. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 1, characterized in that: A waveguide probe is provided on the intermediate tank circulation pipeline, and the waveguide probe is used to transmit electromagnetic waves to the ammonium nitrate solution and receive reflected signals.

8. The automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 7, characterized in that: The specific method for detecting the concentration of ammonium nitrate solution based on non-contact electromagnetic wave spectrum analysis is as follows: Step 1: Multi-band scanning: The waveguide probe transmits electromagnetic waves at a frequency of 1 GHz to 100 GHz, covering the characteristic absorption peak of the ammonium nitrate solution; Step 2: Transmission / reflection detection: Transmission mode: electromagnetic waves penetrate the ammonium nitrate solution, and the receiving end detects the attenuation of the transmitted light; Reflection mode: detects the phase change of the reflected wave on the solution surface; Step 3: Signal amplification and filtering: The preamplifier enhances weak signals and the digital filter removes noise; Step 4: Absorption spectrum analysis: Perform Fourier transform on the collected electromagnetic wave signal to extract the characteristic absorption peak intensity; Step 5: Concentration fitting: Based on the Lambert-Beer law, the concentration value is calculated to obtain the concentration of the ammonium nitrate solution.

9. An automatic detection system for pH value and concentration of ammonium nitrate solution according to claim 8, characterized in that: Also includes: Abnormal detection module, if the pH value of the ammonium nitrate dilution exceeds the preset range, when the pH value is <1.5, an alarm is triggered; When the pH value is <1, the interlock stops.

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