Online detection device for pH of water phase of emulsion explosive

Abstract

The present application belongs to the technical field of emulsion explosive water phase detection, and discloses an emulsion explosive water phase pH online detection device, which comprises a conveying pipeline, a heat tracing regulating valve, a composite detection group and a pneumatic cut-off valve. The present application sets a density correlation coefficient K1 as high as 142.5 and a temperature compensation coefficient K2 as 0.12, and this algorithm can eliminate the fluid volume expansion error caused by high temperature in real time, lock the concentration measurement accuracy within ±0.2%, and through this high-precision soft measurement technology, the device can sensitively capture any slight deviation within the narrow "optimal emulsification concentration window" of 90.0%-93.0%, which not only solves the problem of inaccurate batching caused by measurement error in the background art, but also ensures that every drop of water phase entering the emulsifier is in the most favorable state for forming a stable water-in-oil structure, thereby greatly improving the detonation sensitivity and storage stability of the final explosive product, and eliminating quality accidents caused by water phase concentration fluctuations from the source.

Description

Technical Field

[0001] This invention belongs to the field of aqueous phase detection technology for emulsion explosives, specifically an online pH detection device for the aqueous phase of emulsion explosives. Background Technology

[0002] As a type of water-in-oil (W / O) emulsion explosive, the preparation of the aqueous phase in the production process is crucial. The aqueous phase is mainly a supersaturated solution formed by dissolving ammonium nitrate, water, and other additives at high temperatures. Its pH value, density (concentration), and temperature directly determine the stability of the subsequent emulsion matrix and the sensitization effect of the final product. On existing automated production lines, ensuring that the aqueous solution is in the optimal physicochemical state before entering the emulsifier is a core step in ensuring production safety and product quality.

[0003] However, existing technologies for online detection of the aqueous phase of emulsion explosives generally suffer from problems such as measurement accuracy being greatly affected by environmental interference and the inability to cross-verify single data. Traditional detection methods often focus only on a single pH or density value, neglecting the nonlinear effects of high-temperature conditions (usually above 120°C) on the physical properties of the solution. For example, in the high concentration range, the volume expansion coefficient of the solution changes significantly with temperature, making it impossible to accurately infer the true mass percentage concentration based solely on ordinary density meter readings. This measurement error can lead to the failure to detect batch deviations in a timely manner, allowing unqualified aqueous phases to enter the emulsification process. This can result in emulsification failure and product stratification, or even detonation performance degradation due to uneven distribution of sensitized bubbles, and even the production of waste products, causing huge waste of raw materials and safety hazards.

[0004] Furthermore, existing detection devices have significant design flaws in addressing the risk of crystallization in high-concentration solutions. At concentrations above 90%, the crystallization point of ammonium nitrate aqueous phase is extremely high (close to 100°C), very close to the process temperature window. Existing detection pipelines or bypass systems often lack sophisticated active thermal intervention mechanisms. Once the flow rate decreases or the ambient temperature fluctuates, the fluid is prone to rapid cooling and crystallization on the sensor probe surface or in dead corners of the pipeline. Crystallization not only quickly blocks the sampling pipeline but also covers the glass electrode surface of the pH meter, leading to distorted detection data or equipment damage. At the same time, existing control logic lacks intelligent verification functions and cannot distinguish whether the reading drift is due to probe contamination (such as crystal adhesion) or the raw material itself is truly substandard. Often, an abnormal pH level triggers an emergency shutdown of the entire production line, resulting in low production efficiency and increased unnecessary downtime maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to provide an online pH detection device for the aqueous phase of emulsion explosives to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an online pH detection device for the aqueous phase of emulsion explosives, comprising a delivery pipeline, a heat-tracing regulating valve, a composite detection group, a pneumatic shut-off valve, and a central control and processing module;

[0007] The delivery pipeline is divided into a heat tracing jacket area, a sensor detection area, and a flow control area along the fluid flow direction.

[0008] The heat tracing regulating valve is located at the heat source inlet of the heat tracing jacket area;

[0009] The composite detection group is located in the sensor detection area and includes a pH sensor, a mass flow meter, and a temperature sensor;

[0010] The pneumatic shut-off valve is located in the flow control area; the central control and processing module includes a concentration inversion unit, a solubility analysis unit, and a logic verification unit.

[0011] The concentration inversion unit is used to calculate the corrected concentration value based on the data collected by the mass flow meter and the temperature sensor;

[0012] The solubility analysis unit is used to calculate the theoretical crystallization point based on the concentration value, and to control the opening of the heat tracing regulating valve based on the safety margin of the temperature difference between the real-time temperature and the theoretical crystallization point.

[0013] The logic verification unit is used to cross-verify the pH value, concentration value, and temperature difference safety margin, and controls the opening and closing of the pneumatic shut-off valve based on the verification results.

[0014] As a further technical solution of the present invention, the pH sensor and the mass flow meter are both fixed on the conveying pipeline by being installed at an upward angle, with the angle between their central axis and the horizontal plane being 30° to 60°, so as to use the bubble buoyancy effect to avoid bubbles from accumulating on the probe surface.

[0015] As a further technical solution of the present invention, the pH sensor is a high-temperature resistant industrial online glass electrode; the mass flow meter is a Coriolis mass flow meter; and the temperature sensor is integrated inside the mass flow meter to ensure the synchronization of density and temperature measurements.

[0016] As a further technical solution of the present invention, both the heat tracing regulating valve and the pneumatic shut-off valve are equipped with a fault reset function. When the system loses power or the gas supply is interrupted, the pneumatic shut-off valve automatically resets to the closed state, and the heat tracing regulating valve automatically resets to the fully open state, so as to use residual heat to prevent pipeline crystallization.

[0017] As a further technical solution of the present invention, the central control and processing module is also equipped with a thermal shock cleaning program. When the logic verification unit determines that the sensor may have crystal adhesion, it controls the heat tracing regulating valve to be fully opened for a short time to use superheated fluid to perform thermal shock cleaning on the composite detection group.

[0018] The online pH detection method for the aqueous phase of emulsion explosives includes the following steps:

[0019] S1: Multidimensional data synchronous acquisition; the central control and processing module synchronously acquires the real-time density ρ, real-time temperature T, and real-time pH value of the fluid through the composite detection group;

[0020] S2: Concentration soft measurement based on multivariate regression; the concentration inversion unit calls a preset mathematical model to calculate the mass percentage concentration C after eliminating the high temperature volume expansion error based on real-time density ρ and real-time temperature T.

[0021] S3: Active thermal intervention to prevent crystallization based on solubility margin; the solubility analysis unit calculates the theoretical crystallization point Tcrys based on the concentration C, and monitors the safety margin ΔT of the temperature difference between the real-time temperature T and the theoretical crystallization point Tcrys, and maintains ΔT within the safe range by controlling the opening of the heat tracing regulating valve through PID control.

[0022] S4: Multi-dimensional logic verification and execution strategy; the logic verification unit combines the concentration C, real-time pH value and temperature difference safety margin ΔT to determine the fault type and control the action of the pneumatic shut-off valve.

[0023] As a further technical solution of the present invention, in step S2, the mathematical model is: C=K1*ρ+K2*T+K3, where C is the mass percentage concentration, K1 is the density positive correlation coefficient, K2 is the temperature compensation coefficient, and K3 is the intercept correction constant; for the concentration range of 90%-93%, K1 is set to 142.5 and K2 is set to 0.12.

[0024] As a further technical solution of the present invention, step S2 also includes a K3 intercept adaptive correction mode. In calibration mode, the concentration value Clab from laboratory testing is input into the central control and processing module, and the system calculates the correction value according to the formula. Calculate the deviation and then add ΔK to the original K3 using a weighted compensation method.

[0025] As a further technical solution of the present invention, in step S3, the specific strategy for controlling the heat tracing regulating valve is as follows: when ΔT>15℃, it is determined to be a safe operating zone, and the heat tracing regulating valve maintains an energy-saving opening; when 8℃<ΔT≤15℃, it is determined to be a warning intervention zone, and the PID heating program is started to increase the fluid temperature; when ΔT≤8℃, it is determined to be an emergency heating zone, and the heat tracing regulating valve is forced to open fully.

[0026] As a further technical solution of the present invention, in step S4, the specific strategy for determining the fault type and control action is as follows:

[0027] Logic 1: When an abnormal pH value is detected and the concentration C also exceeds the acceptable range, the raw material is determined to be unqualified, triggering a red alarm and closing the pneumatic shut-off valve;

[0028] Logic 2: When an abnormal pH value is detected, but the concentration C is within the acceptable range and ΔT>15℃, it is determined that the sensor is contaminated or drifting, triggering a yellow maintenance warning and keeping the pneumatic shut-off valve open;

[0029] Logic 3: When the concentration C is detected to deviate significantly from the preset safe range, a red alarm is triggered and the pneumatic shut-off valve is closed.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. This invention, through the mathematical model embedded in the concentration inversion unit, sets a density correlation coefficient K1 of up to 142.5 and a temperature compensation coefficient K2 of 0.12 for the high concentration range. This algorithm can eliminate the fluid volume expansion error caused by high temperature in real time, locking the concentration measurement accuracy within ±0.2%. Through this high-precision soft measurement technology, the device can sensitively capture any slight deviation within the narrow "optimal emulsification concentration window" of 90.0%-93.0%. This not only solves the problem of inaccurate batching caused by measurement error in the background technology, but also ensures that every drop of water phase entering the emulsifier is in the state most conducive to forming a stable water-in-oil structure, thereby greatly improving the detonation sensitivity and storage stability of the final explosive product, and eliminating quality accidents caused by water phase concentration fluctuations from the source.

[0032] 2. This invention employs a proactive defense mechanism based on real-time solubility analysis. Instead of passively waiting for the temperature to decrease, the system utilizes a solubility analysis unit to calculate the theoretical crystallization point (Tcrys) at the current concentration in real time and monitors the safety margin ΔT between the real-time temperature and the crystallization point. Addressing the physical characteristics of 90%-93% high-concentration solutions—high crystallization point and narrow temperature difference window—it raises the conventional temperature control threshold to "15℃ warning and 8℃ emergency response." When ΔT is compressed to below 15℃, the system determines the increased risk and proactively activates the PID heating program of the heat tracing valve. Once the temperature difference is less than 8℃, the system immediately activates the full heat source for strong intervention. This tiered control strategy effectively constructs a dynamic "constant-temperature anti-crystallization protective layer" around the detection probe, ensuring the fluid remains overheated when in contact with the sensor surface. This not only completely solves the problem of pipe blockage caused by localized cold spots but also prevents crystal adhesion and growth on the pH glass electrode surface, significantly extending the online lifespan and measurement accuracy of the precision sensor.

[0033] 3. This invention introduces concentration (C) and temperature (T) as cross-validation factors. When the system detects an abnormal pH value, it automatically checks the concentration value and temperature margin of the same period. If the concentration is within the perfect range of 90%-93% and the temperature is high enough, the logic unit will determine that this is only a low-confidence fault of the sensor, and will only issue a yellow maintenance warning without closing the shut-off valve, allowing production to continue until the predetermined maintenance window. Conversely, only when both the pH value and concentration value are abnormal, or when the concentration deviates to an extreme degree, will the system confirm a high-confidence fault and execute shut-off. This logical judgment mechanism, while ensuring absolute safety, minimizes unnecessary downtime and significantly improves the overall equipment efficiency of the production line. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the system principle structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the monitoring and control logic flow of the present invention;

[0036] Figure 3 This is a three-dimensional schematic diagram of the actual use of the present invention.

[0037] In the diagram: 1. Delivery pipeline; 2. Heat tracing jacket area; 3. Sensor detection area; 4. Flow control area; 5. Heat tracing regulating valve; 6. Composite detection group; 61. pH sensor; 62. Mass flow meter; 63. Temperature sensor; 7. Pneumatic shut-off valve; 8. Central control and processing module; 81. Concentration inversion unit; 82. Solubility analysis unit; 83. Logic verification unit; 84. Threshold storage unit; 9. Audible and visual alarm. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] like Figures 1 to 3 As shown, this embodiment of the invention provides an online pH detection device for the aqueous phase of emulsion explosives. The monitoring system described in this embodiment is installed on the conveying pipeline 1 connecting the upstream raw material tank and the subsequent emulsifier in the emulsion explosive production line. In order to achieve graded control, the conveying pipeline 1 is divided into three functional areas along the fluid flow direction: the heat tracing jacket area 2, the sensor detection area 3, and the flow interception control area 4.

[0040] Heat tracing jacket area 2: The outer wall of the pipeline in this area is equipped with a steam heating jacket or an electric heat tracing cable. A heat tracing regulating valve 5 is installed at the heat source inlet. The regulating valve 5 is preferably a pneumatic diaphragm regulating valve with a 4-20mA analog input interface. It can achieve continuous opening adjustment from 0-100% according to the control signal, and is used to accurately control the temperature of the ammonium nitrate solution flowing through this area.

[0041] Sensor detection area 3: This area is equipped with a composite detection group 6 that directly contacts the fluid, including:

[0042] pH Sensor 61: It uses a high-temperature resistant (above 130℃) industrial online glass electrode with automatic temperature compensation function to collect the pH value of the solution in real time.

[0043] Mass flow meter 62: A Coriolis mass flow meter is preferred, connected in series in the pipeline, for real-time acquisition of high-precision density values ​​of fluids. and flow rate;

[0044] Temperature sensor 63: Used to acquire fluid temperature values ​​(T) in real time, usually integrated inside mass flow meter 62 to ensure synchronization of density and temperature measurements.

[0045] Furthermore, in order to eliminate the interference of tiny bubbles in the fluid on density and pH measurements, the installation method of the composite detection group 6 on the delivery pipeline 1 is specifically designed. Specifically, both the pH sensor 61 and the mass flow meter 62 are installed at an upward angle, with their central axis at an angle of 30° to 60° to the horizontal plane, preferably 45°.

[0046] On the one hand, it utilizes the buoyancy effect of bubbles to allow the trace bubbles entrained in the fluid to pass quickly along the upper edge of the inner wall of the pipe, avoiding the accumulation of bubbles on the surface of the sensor probe that would cause fluctuations in the measurement data. On the other hand, compared with vertical installation, tilted installation can effectively reduce the direct vertical impact of the fluid on the glass electrode, reduce the risk of probe breakage, and avoid the dead corners where sediment may accumulate at the bottom when installed horizontally, ensuring the authenticity of the detection data and the service life of the sensor.

[0047] Interception control zone 4: Located downstream of the detection zone, it is equipped with a pneumatic shut-off valve 7. This valve is either normally closed or shut off when air is cut off, and is used to physically cut off the material supply to the subsequent emulsifier in an emergency.

[0048] Central control and processing module 8: As the core of the system, it adopts a PLC (Programmable Logic Controller) or DCS (Distributed Control System). This module is electrically connected to the aforementioned sensors and actuators. It is internally divided into four logic operation units: concentration inversion unit 81, solubility analysis unit 82, logic verification unit 83, and threshold storage unit 84. In addition, this module is also connected to an audible and visual alarm 9.

[0049] Example 2: This example includes a monitoring and control system for the above-mentioned online detection device. The operating logic of this system includes four core steps: data acquisition, algorithm inversion, risk pre-control, and logic verification.

[0050] S1: Multidimensional Data Synchronous Acquisition: During system operation, the central control and processing module 8 synchronously reads the following real-time data from the composite detection group 6 at a sampling frequency of 500ms to 1s:

[0051] Real-time density ρ (unit: g / cm3);

[0052] Real-time temperature T (unit: °C, operating range is usually between 120 °C and 135 °C);

[0053] Real-time pH value.

[0054] S2: Concentration soft measurement based on multivariate regression: It is executed by concentration inversion unit 81, using a "density-temperature" two-parameter inversion algorithm. Concentration inversion unit 81 retrieves the empirical formula model from threshold storage unit 84.

[0055] C = K1 * ρ + K2 * T + K3;

[0056] Where: C is the mass percentage concentration of ammonium nitrate in the aqueous phase calculated by the inversion (%).

[0057] K1 is the density positive correlation coefficient, which is set to 142.5 for the high concentration range;

[0058] K2 is the temperature compensation coefficient, set to 0.12 (the expansion coefficient increases at high temperatures, so the compensation weight needs to be increased).

[0059] K3 is the intercept correction constant, set to -115.5.

[0060] Assuming the current operating conditions within the pipeline are stable, the sensor collects real-time density ρ = 1.345 g / cm³, and real-time temperature T = 128℃. The system performs instantaneous calculations: C = 142.5*1.345 + 0.12*128 - 115.5, C = 191.66 + 15.36 - 115.5, C = 91.52%. The calculation result falls within the acceptable range of 90%-93%.

[0061] The calibration was specifically designed for the 120-135℃ high-temperature range, effectively compensating for density drift caused by the volume expansion of high-temperature fluids, and ensuring that the measurement error is less than ±0.2% in the high concentration range above 90%.

[0062] It should be noted that the coefficients K1 (density positive correlation coefficient) and K2 (temperature compensation coefficient) in the above formula are obtained by multi-point calibration and linear regression fitting based on the emulsion explosive aqueous phase of specific components (such as pure ammonium nitrate aqueous solution or composite oxidant solution with specific ratio) in a laboratory environment.

[0063] The specific modeling method is as follows: Select multiple sets of standard solutions within the target concentration range (90%-93%), conduct heating and cooling tests within the process temperature range (120℃-135℃), record multiple sets of three-dimensional data points (density, temperature, concentration), and use the least squares method to perform multiple linear regression on the formula C=K1*ρ+K2*T+K3 to calculate the K1, K2 and initial K3 values ​​applicable to the current process formulation.

[0064] In this embodiment, for a specific formulation of ammonium nitrate aqueous phase, regression calculation yielded K1=142.5 and K2=0.12.

[0065] It is worth noting that, considering that the slight differences in trace impurities in different batches of raw materials, such as porous granular ammonium nitrate, may cause slight deviations in the basic density, the concentration inversion unit 81 also has an embedded K3 intercept adaptive correction module.

[0066] The specific operating mode is as follows: The system is set with a "calibration mode". In this mode, the operator inputs the accurate concentration value Clab from the offline laboratory test into the central control and processing module 8, and the system automatically captures the online density at the time of sampling. and temperature And deduce the current actual intercept error based on the formula:

[0067] ;

[0068] The system adds the calculated deviation ΔK to the original intercept K3 as a weighted compensation and updates the system parameters. This dynamic correction mechanism enables the device to have self-learning capabilities and maintain a very high degree of detection consistency as production time progresses and raw materials change.

[0069] S3: Active thermal intervention to prevent crystallization based on solubility margin, which is executed by solubility analysis unit 82. Since the crystallization point of 90%-93% concentration ammonium nitrate solution is relatively high (usually around 95℃-110℃), which is very close to the working temperature (120℃-135℃), the risk of crystallization is much higher than that of low concentration solution. Therefore, a more sensitive temperature difference control strategy is required.

[0070] Calculate the crystallization point: Based on the concentration C obtained in step S2 (e.g., 91.52%), substitute it into the solubility model for the high concentration region: Tcrys = 1.8 * C - 65 (this is a simplified empirical linear model for the high concentration region; for example, 91.5% corresponds to a crystallization point of approximately 99.7℃).

[0071] It is worth noting that, for this specific aqueous formulation, a pre-fitted empirical model for solubility in the high-concentration range was established: Tcrys = A*CB. In this embodiment, for high-concentration ammonium nitrate solutions, experimental results showed that the crystallization point and concentration were approximately linearly related within the 90%-93% range, with fitting coefficients A=1.8 and B=65. The parameters of this model can be adjusted based on the actual solubility curve of the material.

[0072] Calculate the safety margin: ΔT = T - Tcrys (e.g., 128℃ - 99.7℃ = 28.3℃, which is within the safe range);

[0073] Hierarchical PID control strategy:

[0074] Safe operating zone (ΔT>15℃): Determined to have no risk of crystallization, heat tracing regulating valve 5 maintains energy-saving opening;

[0075] Early warning intervention zone (8℃<ΔT≤15℃): For high-concentration solutions, when the temperature difference is compressed to within 15℃, it is considered an increased risk. The system starts PID heating to increase the fluid temperature T and ensure that the temperature difference is maintained above 15℃.

[0076] Emergency heating zone (ΔT≤8℃): When the temperature difference is less than 8℃, it indicates that the solution is very likely to crystallize on the probe surface. The system immediately controls the heating regulating valve 5 to be fully open (100%) and sends a "high concentration critical crystallization warning" to the central control room.

[0077] In response to the physical characteristics of 90-93% high-concentration solutions, which have "high crystallization point and narrow temperature difference window", the warning threshold has been redefined (increased from the conventional 12℃ / 5℃ to 15℃ / 8℃), effectively preventing instantaneous blockage or probe failure caused by local cold spots in the delivery pipeline.

[0078] S4: Multi-dimensional logic verification and execution strategy, which is executed by logic verification unit 83, sets the pH qualified range to [pHmin, pHmax] (e.g., 4.0-6.0), and adjusts the concentration qualified range to [90.0%, 93.0%];

[0079] Logic 1: The raw material is actually substandard (high-confidence fault, requiring interception).

[0080] Judgment criteria: (pH < 4.0 or pH > 6.0) and (C < 90.0% or C > 93.0%).

[0081] Action: Trigger the audible and visual alarm 9 to emit a red audible and visual alarm, and immediately close the pneumatic shut-off valve 7;

[0082] Logic 2: Sensor contamination or drift (low-confidence fault requiring sustained operation and maintenance)

[0083] Judgment criteria: (abnormal pH) and (90.0%≤C≤93.0%) and (ΔT>15℃);

[0084] Action: Trigger the audible and visual alarm 9 to issue a yellow maintenance warning, keep the pneumatic shut-off valve 7 open. At this time, the system judges that the concentration is in the excellent range of 90-93% and the temperature is high enough. The pH alarm is most likely caused by the zero-point drift of the probe due to long-term immersion in high-concentration salt solution.

[0085] For the sensor contamination status determined by logic 2, the central control and processing module 8 is also equipped with an online hot rinsing program:

[0086] When the system continuously triggers yellow maintenance warnings for more than the set time (e.g., 30 minutes) and the production schedule allows, the system can automatically perform the following cleaning actions:

[0087] The heat tracing regulating valve 5 is briefly fully opened, and the superheated fluid (temperature rise of 3-5℃) is used to perform thermal shock on the sensor detection area 3. The difference in thermal expansion caused by the temperature difference causes the tiny crystalline layer attached to the surface of the PH glass electrode to peel off.

[0088] If thermal shock is ineffective, the system prompts for manual intervention. Open the bypass backwash valve (not shown in the figure) located on the side of the pH sensor 61, and introduce high-temperature pure water (temperature > 100℃) to perform targeted spray cleaning on the probe.

[0089] By attempting to utilize the thermal energy of the process fluid itself for self-cleaning, the solution dilution problem that may be caused by introducing external media is avoided. External water sources are only introduced when necessary, thus maximizing the continuity of production and the stability of water phase quality.

[0090] Logic 3: Severely abnormal concentration (absolute malfunction requiring flow throttling)

[0091] Judgment criteria: C < 88.0% (too low concentration leads to emulsification failure) or C > 95.0% (too high concentration leads to sensitization risk);

[0092] Action executed: Directly triggers the audible and visual alarm 9 to issue a red alarm and cuts off the flow.

[0093] In addition, considering the safety requirements of the emulsion explosive production site, all pneumatic actuators of this device are designed with power failure / gas failure safety positions.

[0094] Specifically, when a factory experiences an unexpected power outage or gas supply interruption:

[0095] The pneumatic shut-off valve 7 will automatically reset to the closed state, physically blocking the flow of raw materials to the emulsifier and preventing uncontrolled feeding;

[0096] The heat tracing regulating valve 5 will automatically reset to the fully open state, using the remaining steam or heat source to continuously heat the pipeline.

[0097] Even in the extreme case of a complete plant failure, the residual heat should be used first to prevent the ammonium nitrate solution in pipeline 1 from cooling and crystallizing. This not only protects the instruments and equipment from damage caused by crystallization and compression, but also provides sufficient time for subsequent emergency repairs and resumption of production, avoiding the need for dangerous hot work or complete disassembly and cleaning due to pipeline freezing.

[0098] By narrowing the concentration determination range (locked at 90-93%), the system can more sensitively detect minute fluctuations in the batching process, ensuring that every drop of aqueous phase entering the emulsifier is at the optimal emulsification concentration point, thereby guaranteeing the detonation performance of the final explosive product.

Claims

1. An online pH detection device for the aqueous phase of emulsion explosives, characterized in that: It includes a delivery pipeline (1), a heat tracing regulating valve (5), a composite detection group (6), a pneumatic shut-off valve (7), and a central control and processing module (8). The conveying pipeline (1) is divided into a heat tracing jacket area (2), a sensor detection area (3), and a flow control area (4) along the fluid flow direction. The heat tracing regulating valve (5) is located at the heat source inlet of the heat tracing jacket area (2); The composite detection group (6) is located in the sensor detection area (3) and includes a pH sensor (61), a mass flow meter (62) and a temperature sensor (63). The pneumatic shut-off valve (7) is located in the flow control area (4); the central control and processing module (8) includes a concentration inversion unit (81), a solubility analysis unit (82), and a logic verification unit (83). The concentration inversion unit (81) is used to calculate the corrected concentration value based on the data collected by the mass flow meter (62) and the temperature sensor (63); The solubility analysis unit (82) is used to calculate the theoretical crystallization point based on the concentration value, and to control the opening of the heat tracing regulating valve (5) based on the safety margin of the temperature difference between the real-time temperature and the theoretical crystallization point. The logic verification unit (83) is used to cross-verify the pH value, concentration value and temperature difference safety margin, and control the opening and closing of the pneumatic shut-off valve (7) according to the verification results.

2. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: The pH sensor (61) and the mass flow meter (62) are both fixed on the conveying pipe (1) by being installed at an upward angle. The angle between their central axis and the horizontal plane is 30° to 60°, so as to avoid bubbles from accumulating on the probe surface by utilizing the bubble buoyancy effect.

3. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: The pH sensor (61) is a high-temperature resistant industrial online glass electrode; the mass flow meter (62) is a Coriolis mass flow meter; and the temperature sensor (63) is integrated inside the mass flow meter (62) to ensure the synchronization of density and temperature measurements.

4. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: Both the heat tracing regulating valve (5) and the pneumatic shut-off valve (7) are equipped with a fault reset function. When the system is powered off or the gas supply is interrupted, the pneumatic shut-off valve (7) automatically resets to the closed state, and the heat tracing regulating valve (5) automatically resets to the fully open state, so as to use residual heat to prevent pipeline crystallization.

5. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: The central control and processing module (8) is also equipped with a thermal shock cleaning program. When the logic verification unit (83) determines that the sensor may have crystal adhesion, it controls the heat tracing regulating valve (5) to open fully for a short time to use superheated fluid to perform thermal shock cleaning on the composite detection group (6).

6. A method for online detection of pH in the aqueous phase of emulsion explosive based on the apparatus described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Multidimensional data synchronous acquisition; The central control and processing module (8) synchronously acquires the real-time density ρ, real-time temperature T and real-time pH value of the fluid through the composite detection group (6); S2: Concentration soft measurement based on multivariate regression; The concentration inversion unit (81) calls the preset mathematical model and calculates the mass percentage concentration C after eliminating the high temperature volume expansion error based on the real-time density ρ and the real-time temperature T. S3: Active thermal intervention to prevent crystallization based on solubility margin; the solubility analysis unit (82) calculates the theoretical crystallization point Tcrys based on the concentration C, and monitors the safety margin ΔT of the temperature difference between the real-time temperature T and the theoretical crystallization point Tcrys, and controls the opening of the heat tracing regulating valve (5) through PID to keep ΔT within the safe range. S4: Multidimensional logic verification and execution strategy; The logic verification unit (83) combines the concentration C, real-time pH value and temperature difference safety margin ΔT to determine the fault type and control the action of the pneumatic shut-off valve (7).

7. The online pH detection device for the aqueous phase of emulsion explosives according to claim 6, characterized in that: In step S2, the mathematical model is: C=K1*ρ+K2*T+K3, where C is the mass percentage concentration, K1 is the density positive correlation coefficient, K2 is the temperature compensation coefficient, and K3 is the intercept correction constant; for the concentration range of 90%-93%, K1 is set to 142.5 and K2 is set to 0.

12.

8. The online pH detection device for the aqueous phase of emulsion explosives according to claim 7, characterized in that: Step S2 further includes a K3 intercept adaptive correction mode. In calibration mode, the concentration value Clab from laboratory testing is input into the central control and processing module (8), and the system calculates the result according to the formula. Calculate the deviation and then add ΔK to the original K3 using a weighted compensation method.

9. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: In step S3, the specific strategy for controlling the heat tracing regulating valve (5) is as follows: when ΔT>15℃, it is determined to be a safe operating zone, and the heat tracing regulating valve (5) maintains an energy-saving opening; when 8℃<ΔT≤15℃, it is determined to be a warning intervention zone, and the PID heating program is started to increase the fluid temperature; when ΔT≤8℃, it is determined to be an emergency heating zone, and the heat tracing regulating valve (5) is forced to open fully.

10. The online pH detection device for the aqueous phase of emulsion explosives according to claim 1, characterized in that: In step S4, the specific strategy for determining the fault type and control action is as follows: Logic 1: When an abnormal pH value is detected and the concentration C also exceeds the qualified range, it is determined that the raw material is unqualified, triggering a red alarm and closing the pneumatic shut-off valve (7). Logic 2: When an abnormal pH value is detected, but the concentration C is within the acceptable range and ΔT>15℃, it is determined that the sensor is contaminated or drifting, triggering a yellow maintenance warning and keeping the pneumatic shut-off valve (7) open; Logic 3: When the concentration C is detected to deviate significantly from the preset safe range, a red alarm is triggered and the pneumatic shut-off valve (7) is closed.

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