Automatic detection device for combustible in ammonium nitrate

Abstract

The present application relates to the technical field of combustible substance detection in ammonium nitrate, and provides an automatic device for detecting combustible substance in ammonium nitrate, which comprises a reagent storage unit for storing ammonium nitrate sample, sodium persulfate reagent and phosphoric acid reagent; a CO2 infrared analyzer is connected with the reagent storage unit, the CO2 infrared analyzer can receive the reagent supplied by the reagent storage unit and determine the content of CO2 after the combustible substance in the ammonium nitrate sample is oxidized by the sodium sulfate reagent to form CO2; a controller controls the reagent storage unit to supply the reagent to the CO2 infrared analyzer, and receives and analyzes the content information of CO2 determined by the CO2 infrared analyzer to obtain the content of combustible substance in ammonium nitrate. The automatic device for detecting combustible substance in ammonium nitrate provided by the present application realizes efficient detection of combustible substance by using wet oxidation-infrared quantitative technology.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of flammable material detection technology in ammonium nitrate, and specifically to an automatic detection device for flammable materials in ammonium nitrate. Background Technology

[0002] Ammonium nitrate is a basic chemical raw material widely used in agricultural fertilizers, civil explosives, and chemical industries. At the same time, it is a strong oxidizing hazardous chemical that is prone to violent decomposition or even explosion when exposed to high temperatures or impacts.

[0003] Combustible materials (organic impurities, oils, carbonaceous substances, etc.) mixed in ammonium nitrate are the core factors affecting its thermal stability and explosion risk. The mixture of these two substances forms an explosive mixture, significantly lowering the detonation threshold of ammonium nitrate and increasing its destructive power. Many major ammonium nitrate explosions are directly related to excessive levels of combustible materials. Therefore, the combustible material content is a crucial safety indicator for ammonium nitrate products, and its detection accuracy, efficiency, and safety directly determine the industry's level of safety management.

[0004] Currently, the detection of flammable substances in ammonium nitrate mainly relies on two standards: GB / T29879-2013 and HG / T4523-2024. GB / T29879-2013 uses a high-temperature ignition weighing method, but ammonium nitrate decomposes violently above 230℃. This not only poses an explosion risk during the testing process but also results in significantly inaccurate test results due to complete decomposition, failing to provide effective quality control data. The HG / T4523-2024 method requires multiple instruments, is cumbersome, and has a single-sample testing cycle of up to 5 hours, making it difficult to meet the continuous batch testing needs of manufacturers. Furthermore, the titration endpoint is highly dependent on human experience, leading to significant human error and poor repeatability.

[0005] Existing testing technologies generally fail to balance safety, convenience, and efficiency, making it difficult to meet the actual needs of safe production and batch quality control in the ammonium nitrate industry. There is an urgent need to develop efficient testing devices that meet the industry's requirements. Summary of the Invention

[0006] To overcome the above-mentioned defects, embodiments of the present invention provide an automatic detection device for combustibles in ammonium nitrate, which solves the technical problems of low detection efficiency and high safety risks in related technologies.

[0007] According to one aspect, at least one embodiment of the present invention provides an automatic detection device for combustibles in ammonium nitrate, comprising: A reagent storage unit for storing ammonium nitrate samples, sodium persulfate reagent, and phosphoric acid reagent; The CO2 infrared analyzer is connected to the reagent storage unit. The CO2 infrared analyzer is used to receive reagents supplied by the reagent storage unit, so that sodium persulfate reagent can oxidize the combustibles in the ammonium nitrate sample in the acidic environment formed by the phosphoric acid reagent to generate CO2. The CO2 infrared analyzer is also used to determine the CO2 content and generate content information. The controller is used to control the reagent storage unit to supply reagents to the CO2 infrared analyzer and to receive and analyze the CO2 content information measured by the CO2 infrared analyzer to determine the combustible content in ammonium nitrate.

[0008] One possible implementation also includes: The CO2 infrared analyzer is connected to the reagent storage unit via the supply component, and the controller can control the supply component to supply the reagents in the reagent storage unit to the CO2 infrared analyzer.

[0009] In one possible implementation, the reagent storage unit includes: Ammonium nitrate sample bottle, used for storing ammonium nitrate samples; Sodium persulfate reagent bottle, used for storing ammonium persulfate reagent; Phosphoric acid reagent bottle, used to store phosphoric acid reagent; The feeding assembly comprises several components, with each of the ammonium nitrate sample bottle, the sodium persulfate reagent bottle, and the phosphate reagent bottle connected to one feeding assembly.

[0010] In one possible implementation, the supply component includes: The delivery tube has its input end connected to the ammonium nitrate sample bottle, the sodium persulfate reagent bottle, or the phosphate reagent bottle, and its output end connected to the CO2 infrared analyzer. A self-priming pump is installed on the delivery pipe, and the self-priming pump is electrically connected to the controller.

[0011] In one possible implementation, the feeding component further includes: A flow meter is installed on the delivery pipe, and the flow meter is used to display the flow rate of the delivered reagent; A solenoid valve is installed on the delivery pipe, and the solenoid valve is used to control the opening and closing of the delivery pipe.

[0012] In one possible implementation, The delivery pipe is divided into a suction section and a delivery section from its input end to its output end, and the self-priming pump, the flow meter and the solenoid valve are all located in the delivery section; The conveying section is of constant diameter, the diameter of the suction section gradually decreases along the conveying direction, and the suction section is smoothly connected to the conveying section.

[0013] In one possible implementation, The inlet end of the delivery pipe is smoothly connected to a guide ring, and the guide ring has a circular cross-section.

[0014] One possible implementation also includes: A blow-off pipe, connected to the conveying pipe, is used to blow out residual substances in the conveying pipe to clean the conveying pipe. A solenoid valve is provided on the blow-off pipe. A nitrogen cylinder is connected to the input end of the purge tube, and the nitrogen cylinder is used to supply nitrogen to the purge tube.

[0015] One possible implementation also includes: An output tube is connected to the CO2 infrared analyzer, and the output tube is used to output the substances reacted inside the CO2 infrared analyzer.

[0016] The beneficial effects of the embodiments of the present invention are as follows: In this invention, a closed-loop system for detecting combustibles in ammonium nitrate is constructed by combining a reagent storage unit, a CO2 infrared analyzer, and a controller. The three core units work together through fluid pathways, electrical connections, and signal connections, fully covering all detection stages, including reagent storage, reaction detection, process control, and data processing. This fundamentally solves the problems of complex operation, long detection cycle, high safety risks, and distorted detection results in existing detection methods.

[0017] The reagent storage unit achieves isolated storage of different media through independent sealed cavities, avoiding premature contact and side reactions between different media. The CO2 infrared analyzer integrates oxidation reaction and quantitative CO2 detection through its built-in sealed reaction chamber and optical detection chamber, eliminating the need for multiple instruments and sample transfer operations, simplifying the detection process, and avoiding interference from ambient CO2 and sample loss during sample transfer. Furthermore, the wet-method room-temperature oxidation reaction path completely avoids the safety risks of thermal decomposition and explosion of ammonium nitrate in existing high-temperature incineration methods. The detection process is safe and controllable, the oxidation reaction is complete, and the detection results have a high degree of consistency with the actual combustible content.

[0018] The controller, through the cooperation of the timing control module and the data processing module, simultaneously realizes the fully automated control of the detection process and the automated calculation of detection data. This ensures the consistency of reaction conditions and operation timing in different batches of detection processes, eliminates subjective and random errors caused by manual titration and calculation, and improves the repeatability and accuracy of detection results. Through pre-stored standard curves and standardized conversion formulas, it realizes the fully automated conversion from CO2 detection signals to combustible content. The detection data is traceable and adapts to the batch and continuous quality control testing needs in industrial production.

[0019] The reagent storage unit, CO2 infrared analyzer, and controller form a complementary organic whole. The reagent storage unit provides a stable medium supply for the detection process, the CO2 infrared analyzer provides the core reaction and quantitative detection basis, and the controller provides standardized control and data processing support for the entire process. Together, the three components enable automated and highly safe detection of flammable substances in ammonium nitrate. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of the present invention and these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of an automatic detection device for combustibles in ammonium nitrate provided in an embodiment of the present invention; Figure 2 This is an embodiment of the present invention. Figure 1 A magnified view of the structure at point A in the middle; Figure 3 This is an embodiment of the present invention. Figure 1 Schematic diagram of the cross-sectional structure of the central guide ring; In the diagram: 1-Reagent storage unit, 11-Ammonium nitrate sample bottle, 12-Sodium persulfate reagent bottle, 13-Phosphoric acid reagent bottle, 2-CO2 infrared analyzer, 3-Controller, 4-Feeding assembly, 41-Transfer pipe, 411-Absorption section, 412-Transfer section, 42-Self-priming pump, 43-Flow meter, 44-Solenoid valve, 45-Guide ring, 51-Purge pipe, 52-Nitrogen cylinder, 6-Output pipe. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0026] To make the drawings concise and easy to understand, some drawings only show one of the components with the same structure or function, or only one of them is marked. In this article, "one" not only means "only one", but can also mean "more than one", and "several" includes "two" and "more than two".

[0027] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0028] like Figures 1-3 As shown, an automatic detection device for combustibles in ammonium nitrate according to an embodiment of the present invention is illustrated, including a reagent storage unit 1, a CO2 infrared analyzer 2, and a controller 3.

[0029] The reagent storage unit 1 is equipped with independent sealed cavities, each used to hold ammonium nitrate samples, sodium persulfate reagent, and phosphoric acid reagent, respectively. Each sealed cavity is equipped with a controlled-opening and closing supply interface, which is connected to the sample inlet of the CO2 infrared analyzer 2 via a fluid passage. The controlled end of the reagent storage unit 1 is electrically connected to the control output of the controller 3, receiving control signals from the controller 3 to control the opening and closing of each supply interface and the media supply process.

[0030] The CO2 infrared analyzer 2 internally comprises an interconnected sealed reaction chamber and an optical detection chamber. The sample inlet of the sealed reaction chamber is connected to the supply interface of the reagent storage unit 1, receiving various media supplied by the reagent storage unit 1 and providing a sealed space for the oxidation reaction of combustibles and oxidants in the media. This allows the combustibles in the ammonium nitrate sample to be oxidized by sodium persulfate to generate CO2 under acidic conditions. The optical detection chamber houses a non-dispersive infrared optical detection module for quantitative detection of the generated CO2, generating an electrical signal corresponding to the CO2 content. The signal output of the CO2 infrared analyzer 2 is communicatively connected to the signal receiving end of the controller 3, transmitting the generated electrical signal to the controller 3 in real time.

[0031] The controller 3 has a built-in timing control module, data storage module, and data processing module. The timing control module generates and outputs control commands to control the start, stop, timing, and supply volume of the medium delivery action of the reagent storage unit 1. The data storage module is used to pre-store calibration data, which is the total carbon standard curve. Specifically, the standard curve is plotted as follows: A standard solution containing 1.0 mg of carbon (C) is prepared using potassium hydrogen phthalate; 0.00 mL, 1.00 mL, 2.00 mL, 3.00 mL, and 4.00 mL of the total carbon standard solution are transferred to 100 mL volumetric flasks, diluted to the mark with carbon dioxide-free water, and shaken well. The solutions are measured sequentially from low to high concentration. For each standard solution measured, the instrument automatically aspirates 5.0 mL of the corresponding standard solution, 0.50 mL of phosphoric acid solution, and 2.00 mL of sodium persulfate solution. After 10 minutes, the instrument automatically measures the peak area of ​​the standard curve solution. The peak area of ​​the blank solution is subtracted from the peak area of ​​each standard solution. The standard curve is plotted with the carbon mass concentration (mg / L) as the abscissa and the corresponding peak area as the ordinate. This standard curve is obtained by pre-calibration with carbon-containing standard solutions of gradient concentrations. The linear regression equation is obtained by fitting the peak area detected by CO2 infrared analyzer 2 after deducting the blank background with the carbon mass concentration as the abscissa and the peak area detected by CO2 infrared analyzer 2 after deducting the blank background as the ordinate. The data processing module receives the electrical signals transmitted by the CO2 infrared analyzer 2, processes the detection data, and calculates the combustible content. The specific measurement and calculation process is as follows: First, data preprocessing: the received electrical signals are filtered, the detection peak area is extracted, and the background peak area obtained from the blank test is subtracted simultaneously to obtain the net peak area; Second, carbon concentration conversion: the net peak area is substituted into the linear regression equation pre-stored in the data storage module to calculate the total carbon mass concentration in the sample solution; Third, final calculation of combustible content: based on the sample weight, fixed volume, and dilution factor of the ammonium nitrate sample, the combustible content in the ammonium nitrate sample, characterized by the total carbon content, is calculated using a preset formula: w=(ρ×V×f) / m, where w is the combustible content in ammonium nitrate, ρ is the total carbon mass concentration in the sample solution, V is the fixed volume of the ammonium nitrate sample, f is the dilution factor of the sample, and m is the sample weight of the ammonium nitrate sample; Fourth, result output: the calculated combustible content data is stored and output.

[0032] The design principle of this embodiment is as follows: by utilizing the strong oxidizing property of sodium persulfate under acidic conditions, the combustibles in the ammonium nitrate sample are completely oxidized into CO2. The generated CO2 is quantified by a CO2 infrared analyzer 2, and the detection process is automatically controlled and the data is automatically converted by a controller 3. Finally, the content of combustibles in ammonium nitrate is obtained, thus avoiding the safety risks of the existing high-temperature burning method and the problems of complex operation and large error of the titration method.

[0033] The workflow of this embodiment is as follows: The timing control module of controller 3 outputs a control signal to reagent storage unit 1 according to a preset program, controlling reagent storage unit 1 to supply ammonium nitrate sample, phosphoric acid reagent, and sodium persulfate reagent to the sealed reaction chamber of CO2 infrared analyzer 2 according to a preset timing and preset dosage; After various media enter the sealed reaction chamber, the oxidation reaction is completed in the sealed environment, and the combustibles in the ammonium nitrate sample are oxidized to generate CO2; The CO2-containing gaseous medium generated by the reaction enters the optical detection chamber, and CO2 infrared analyzer 2 quantitatively detects the CO2 content, generates the corresponding electrical signal, and transmits it to controller 3; Controller 3 processes and calculates the received electrical signal, and finally obtains and outputs the content result of combustibles in ammonium nitrate, completing a single detection process.

[0034] In this embodiment, a closed-loop system for detecting combustibles in ammonium nitrate is constructed by combining reagent storage unit 1, CO2 infrared analyzer 2, and controller 3. The three core units form a functional synergy through fluid pathways, electrical connections, and signal connections, fully covering all detection links of reagent storage, reaction detection, process control, and data processing. This fundamentally solves the problems of complex operation, long detection cycle, high safety risk, and distorted detection results in existing detection methods.

[0035] The reagent storage unit 1 achieves isolated storage of different media through independent sealed cavities, avoiding premature contact and side reactions between different media. The CO2 infrared analyzer 2 integrates oxidation reaction and quantitative CO2 detection through its built-in sealed reaction chamber and optical detection chamber, eliminating the need for multiple instruments and sample transfer operations, simplifying the detection process, and avoiding interference from ambient CO2 and sample loss during sample transfer. Simultaneously, the wet-method room-temperature oxidation reaction path completely avoids the safety risks of thermal decomposition and explosion of ammonium nitrate in existing high-temperature incineration methods. The detection process is safe and controllable, the oxidation reaction is complete, and the detection results have a high degree of consistency with the actual combustible content.

[0036] Controller 3, through the cooperation of the timing control module and the data processing module, simultaneously realizes the automatic control of the entire detection process and the automatic calculation of detection data. This ensures the consistency of reaction conditions and operation timing in different batches of detection processes, eliminates subjective and random errors caused by manual titration and calculation, and improves the repeatability and accuracy of detection results. Through pre-stored standard curves and standardized conversion formulas, it realizes the fully automatic conversion from CO2 detection signals to combustible content. The detection data is traceable and adapts to the batch and continuous quality control detection needs in industrial production.

[0037] The reagent storage unit 1, CO2 infrared analyzer 2, and controller 3 form a complementary organic whole. The reagent storage unit 1 provides a stable medium supply for the detection process, the CO2 infrared analyzer 2 provides the core reaction and quantitative detection basis for the detection, and the controller 3 provides standardized control and data processing support for the entire process. The three work together to realize the automated and highly safe detection of combustibles in ammonium nitrate.

[0038] Furthermore, it also includes a delivery component 4, which is disposed in the fluid passage between the reagent storage unit 1 and the CO2 infrared analyzer 2. The medium input end of the delivery component 4 is connected to the delivery interface of the reagent storage unit 1, and the medium output end of the delivery component 4 is connected to the sample inlet of the sealed reaction chamber of the CO2 infrared analyzer 2. The controlled end of the delivery component 4 is electrically connected to the control output end of the controller 3, receives the control signal output by the controller 3, and performs the actions of medium absorption, delivery, and stop.

[0039] The timing control module of controller 3 outputs corresponding control commands to the supply component 4 according to the preset detection program, controls the start, stop, running parameters and running time of the supply component 4, and supplies the corresponding medium in reagent storage unit 1 to CO2 infrared analyzer 2 according to preset dosage and preset timing.

[0040] In this embodiment, a dedicated media delivery channel is constructed by adding a delivery component 4 between the reagent storage unit 1 and the CO2 infrared analyzer 2, which converts the control commands of the controller 3 into media delivery actions.

[0041] The supply component 4 serves as a dedicated transport medium between the reagent storage unit 1 and the CO2 infrared analyzer 2, enabling fully enclosed transport of the medium and preventing contact between the medium and the external environment. This not only prevents CO2 from dissolving into the medium and causing background interference, thus improving the accuracy of the detection results, but also avoids the impact of the volatilization of corrosive reagents on operators and the environment, thereby enhancing the safety of the detection process.

[0042] Furthermore, the reagent storage unit 1 includes an ammonium nitrate sample bottle 11, a sodium persulfate reagent bottle 12, and a phosphate reagent bottle 13.

[0043] Ammonium nitrate sample bottle 11, sodium persulfate reagent bottle 12, and phosphoric acid reagent bottle 13 are independent sealed containers used to hold ammonium nitrate samples, sodium persulfate reagent, and phosphoric acid reagent, respectively. Each bottle is equipped with a sealed interface for pipe insertion to prevent the medium inside the bottle from contacting the outside air.

[0044] The number of delivery components 4 matches the number of reagent bottles. Ammonium nitrate sample bottle 11, sodium persulfate reagent bottle 12, and phosphate reagent bottle 13 are each connected to an independent set of delivery components 4. The input end of each delivery component 4 is inserted into the corresponding reagent bottle, extending below the liquid surface of the medium inside the bottle. The output end of each delivery component 4 is connected to the sample inlet of the sealed reaction chamber of the CO2 infrared analyzer 2. The controller 3 is independently electrically connected to the controlled end of each delivery component 4, allowing independent control of the operating status, start / stop sequence, and delivery parameters of each delivery component 4.

[0045] In this embodiment, by setting the reagent storage unit as three independent reagent bottles and configuring an independent supply component 4 for each reagent bottle, independent storage and independent delivery of different media are realized. This structurally avoids cross-contamination between different media and also eliminates the problem of side reactions caused by premature mixing of different media during delivery, thus ensuring the controllability of the oxidation reaction and the accuracy of the detection results.

[0046] The architecture of independent reagent bottles with independent delivery components allows the controller 3 to control the delivery process of each medium completely independently. It can set corresponding control parameters according to the preset delivery dosage, delivery flow rate and delivery sequence of different media, without sharing delivery path and control unit, which greatly improves the flexibility and control accuracy of medium delivery and adapts to the delivery needs of different reagents.

[0047] The independent channel design allows for independent cleaning and purging of each delivery path after a single test, avoiding residual contamination between different reagents and samples, reducing the difficulty of pipeline cleaning, minimizing cross-interference between batches, further improving the repeatability of results during batch testing, and shortening the cleaning waiting time between batches, thus improving the efficiency of batch testing.

[0048] Furthermore, the supply component 4 includes a delivery pipe 41 and a self-priming pump 42. The delivery pipe 41 is a continuous closed fluid passage, with its inlet end inserted into the interior of the corresponding reagent bottle and extending below the liquid surface of the medium inside the bottle, and its outlet end connected to the sample inlet of the closed reaction chamber of the CO2 infrared analyzer 2, forming a closed delivery channel from the reagent bottle to the reaction chamber.

[0049] The self-priming pump 42 is connected in series on the delivery pipe 41. The power control terminal of the self-priming pump 42 is electrically connected to the control output terminal of the controller 3. The controller 3 controls the start, stop, operating speed, and running time of the self-priming pump 42 by outputting control signals, thereby controlling the delivery flow rate, delivery direction, and total delivery volume of the medium in the delivery pipe 41. The controller 3 has a pre-stored target delivery volume for the corresponding medium. Based on the calibrated flow parameters of the self-priming pump 42, the target volume of medium is quantitatively delivered by controlling the running time of the self-priming pump 42.

[0050] In this embodiment, the combination of the delivery pipe and the self-priming pump constitutes the core delivery structure of the delivery component, providing an independent sealed delivery channel for each medium. At the same time, the self-priming pump enables the active absorption and delivery of the medium without applying additional pressure to the reagent bottle, simplifying the overall structure of the device and reducing the assembly and maintenance costs of the equipment.

[0051] The structure of the self-priming pump and the controller being electrically connected allows the controller to control the media delivery by controlling the operating parameters of the self-priming pump. It can flexibly adjust the delivery flow rate and delivery volume according to the delivery requirements of different reagents, and adapt to different sample injection volume requirements of ammonium nitrate samples, oxidants, and acidifying reagents.

[0052] Independent delivery pipes and self-priming pumps correspond to independent reagent bottles, further enhancing the independence of each medium delivery channel and avoiding cross-contamination problems caused by sharing pump bodies and pipelines.

[0053] Furthermore, the supply assembly 4 also includes a flow meter 43 and a solenoid valve 44. Along the medium conveying direction, the solenoid valve 44, the self-priming pump 42, and the flow meter 43 are sequentially connected in series on the conveying pipe 41. The controlled end of the solenoid valve 44 is electrically connected to the control output end of the controller 3. The controller 3 controls the fully open and fully closed state of the solenoid valve 44 through control signals, thereby controlling the opening and closing of the conveying pipe 41. The signal output end of the flow meter 43 is electrically connected to the signal receiving end of the controller 3. The flow meter 43 collects the instantaneous flow rate data of the medium in the conveying pipe 41 in real time and uploads the collected flow rate data to the controller 3 in real time.

[0054] The controller 3 has a preset target delivery volume for the corresponding medium. The controller 3 receives the instantaneous flow data uploaded by the flow meter 43, performs cumulative integration calculation on the instantaneous flow, and obtains the volume of the medium that has been delivered. When the cumulatively calculated delivered volume reaches the preset target delivery volume, the controller 3 synchronously outputs a control signal, closes the solenoid valve 44 and stops the operation of the self-priming pump 42, forming a closed-loop quantitative injection control.

[0055] In this embodiment, by adding a flow meter 43 and a solenoid valve 44 to the delivery pipeline, a closed-loop metering and control system is formed with the self-priming pump 42 and the controller 3. Compared with the scheme of controlling the injection volume by simply controlling the running time of the self-priming pump 42, the metering accuracy of the medium delivery volume is greatly improved, and the volume error caused by pump flow fluctuations and pipeline pressure changes is eliminated. This provides a core guarantee for the precise control of the oxidation reaction, thereby ensuring the accuracy and repeatability of the detection results.

[0056] Furthermore, the delivery pipe 41 is divided into an absorption section 411 and a delivery section 412 along the medium delivery direction. The absorption section 411 is the section of the delivery pipe 41 inserted into the reagent bottle, with its input end below the liquid surface of the medium inside the reagent bottle, and its output end extending out of the reagent bottle and connecting to the input end of the delivery section 412. The delivery section 412 is the section of the delivery pipe 41 located outside the reagent bottle, with the self-priming pump 42, flow meter 43, and solenoid valve 44 all connected in series on the pipeline of the delivery section 412. The delivery section 412 is a constant diameter pipe section with no abrupt changes in pipe diameter, no steps, and no throttling structures on the inner wall of the pipeline. The suction section 411 is a pipe section with a gradually changing inner diameter, which gradually decreases along the medium conveying direction. The inner diameter of the output end of the suction section 411 is completely consistent with the inner diameter of the conveying section 412. The output end of the suction section 411 and the input end of the conveying section 412 are connected by a smooth transition structure without steps. There are no sharp edges, no sudden changes in inner diameter, and no changes in the cross-sectional area of ​​the flow channel at the connection.

[0057] In this embodiment, by dividing the delivery pipe into an absorption section 411 and a delivery section 412, and designing the pipe diameter structure of the two sections differently, the flow state of the medium is optimized from the perspective of the pipeline flow channel structure, reducing the generation of bubbles during the injection process, avoiding the interference of bubbles on the flow meter measurement accuracy, and further improving the stability and accuracy of the detection.

[0058] The suction section 411 adopts a tapered structure that gradually decreases along the conveying direction, which greatly expands the cross-sectional area of ​​the pipeline inlet and reduces the local flow velocity of the medium at the inlet. This avoids the problem of air bubbles being generated by the vortex formed by high-speed liquid entry and the entrainment of air on the liquid surface. At the same time, the tapered structure allows the medium flow velocity to be increased steadily, avoiding sudden changes in flow velocity and local negative pressure fluctuations caused by sudden changes in pipe diameter. This reduces the possibility of dissolved air and CO2 in the medium precipitating out and forming tiny bubbles due to sudden pressure drops.

[0059] The conveying section 412 adopts a constant diameter structure throughout, eliminating flow field disturbances and negative pressure zones caused by sudden changes in pipe diameter and throttling structures in the pipeline. This ensures stable flow of the medium within the conveying section 412, avoids the generation and accumulation of bubbles, and simultaneously ensures the stability of the flow field within the flowmeter detection area, improving the flowmeter's measurement accuracy. The smooth connection structure between the suction section 411 and the conveying section 412 eliminates steps and sharp edges at the connection, preventing boundary layer separation and eddies generated when the medium flows through the connection. This further reduces the probability of bubble generation and avoids cross-contamination problems caused by residual liquid at the connection.

[0060] Furthermore, refer to Figure 2 and Figure 3As shown, the input end of the delivery pipe 41, which is also the inlet end of the suction section 411, is smoothly connected to a guide ring 45. The guide ring 45 is an annular structure with a circular cross-section. The inner annular surface of the guide ring 45 smoothly transitions to the inner wall of the inlet end of the suction section 411, and the outer annular surface of the guide ring 45 smoothly transitions to the outer wall of the inlet end of the suction section 411. There are no seams, steps, or sharp edges at the connection between the guide ring 45 and the suction section 411, and both the inner and outer edges of the guide ring 45 are smooth transition structures.

[0061] In this embodiment, by setting a circular cross-section guide ring at the input end of the delivery pipe 41 and smoothly connecting it to the inlet end of the suction section 411, the sharp edges and corners of the pipe inlet end are eliminated, further optimizing the medium flow field at the inlet and enhancing the anti-bubble and anti-vortex effects.

[0062] The circular cross-section guide ring ensures a smooth transition at the edge of the pipeline inlet, avoiding boundary layer separation and local negative pressure cavities caused by the medium flowing through the sharp edge of the inlet. It also eliminates the generation of eddies and the precipitation of dissolved gases caused by sharp edges, significantly reducing the probability of bubble formation at the inlet. At the same time, the smooth guide structure makes the liquid flow field at the inlet more stable, reducing the disturbance of the liquid surface in the reagent bottle caused by the liquid inlet action. This avoids the problem of vortex formation caused by liquid surface fluctuations and the entrainment of air into the pipeline, thus reducing the possibility of gas intake and gas generation at the source.

[0063] Furthermore, the automatic detection device for combustibles in ammonium nitrate also includes a nitrogen purging unit, which includes a purging pipe 51 and a nitrogen cylinder 52.

[0064] Nitrogen cylinder 52 is used to store high-purity nitrogen. Its output end is equipped with a pressure regulating component to output nitrogen at a stable pressure. The input end of purging pipe 51 is connected to the outlet of the pressure regulating component of nitrogen cylinder 52. The output end of purging pipe 51 has multiple branch lines, each branch line connected to the delivery pipe 41 of each group of supply components 4. Solenoid valves are installed in series on the main pipe and each branch line of purging pipe 51. The controlled end of each solenoid valve is electrically connected to the control output end of controller 3. Controller 3 controls the opening and closing of each solenoid valve through control signals, thereby controlling the nitrogen purging process of the corresponding pipeline.

[0065] The controller 3 has a preset nitrogen purging sequence program. The purging process includes two stages: the first stage is the background purging stage before detection. Before the medium is supplied, the controller 3 controls the corresponding solenoid valve to open. Nitrogen gas enters the delivery pipe 41, the sealed reaction chamber and optical detection chamber of the CO2 infrared analyzer 2 through the purging pipe 51 to purge the air in the pipeline and the chamber and eliminate the background interference caused by CO2 in the environment. The second stage is the cleaning and purging stage after detection. After a single detection is completed, the controller 3 controls the corresponding solenoid valve to open. Nitrogen gas enters the delivery pipe 41, the reaction chamber and the detection chamber through the purging pipe 51 to purge and discharge the residual waste liquid and waste gas in the pipeline and the chamber, completing the cleaning of the pipeline and the chamber.

[0066] In this implementation, by adding a nitrogen cylinder 52 and a purging pipe 51 to the purging structure, an inert gas purging function is provided for the device. In conjunction with the automatic control of the controller 3, the fully automated operation of background elimination before detection and pipeline cleaning after detection is realized, which not only improves the accuracy of the detection results, but also improves the automation level of the device and the efficiency of batch detection.

[0067] The background purging process before testing can completely replace the air in the pipeline, reaction chamber, and detection chamber with high-purity nitrogen, eliminating the interference of CO2 in the air on the test results.

[0068] Furthermore, it also includes an output tube 6. The input end of the output tube 6 is connected to the optical detection chamber and the outlet end of the sealed reaction chamber of the CO2 infrared analyzer 2, and the output end of the output tube 6 is connected to the waste liquid and waste gas collection and treatment device to form a sealed discharge passage, which is used to collect and discharge the waste liquid and waste gas after the oxidation reaction is completed, as well as the nitrogen and residual media in the purging process, to the collection and treatment device.

[0069] In this embodiment, by adding an output tube 6 connected to the CO2 infrared analyzer 2, a dedicated closed discharge passage is provided for the waste liquid and waste gas after the reaction, realizing centralized collection and treatment of waste liquid and waste gas.

[0070] The sealed discharge structure of the output tube can promptly discharge the waste liquid and waste gas after the reaction, avoiding the accumulation of waste liquid and waste gas in the reaction chamber and detection chamber, which would cause the system pressure to rise. This prevents system pressure fluctuations from affecting the detection stability of the CO2 infrared analyzer 2, avoids detection baseline drift, and ensures the stability and accuracy of CO2 detection data. At the same time, the fully sealed discharge passage prevents outside air from flowing back into the detection chamber through the outlet, eliminating the interference of CO2 in the backflowing air with the detection results.

[0071] Furthermore, a solenoid valve and a flow meter are connected in series on the output pipe 6.

[0072] The controlled end of the solenoid valve is electrically connected to the control output end of the controller 3. The controller 3 controls the fully open and fully closed state of the solenoid valve through the control signal, thereby controlling the opening and closing of the output pipe 6. The signal output end of the flow meter is electrically connected to the signal receiving end of the controller 3. The flow meter collects the instantaneous flow data of the fluid in the output pipe 6 in real time and uploads the collected flow data to the controller 3 in real time.

[0073] According to different stages of the detection process, the controller 3 controls the opening and closing state of the solenoid valve: during the CO2 content detection stage, the controller 3 controls the solenoid valve to remain closed, so that the optical detection chamber of the CO2 infrared analyzer 2 and the sealed reaction chamber remain sealed, ensuring the pressure inside the chamber is stable and preventing CO2 leakage; during the waste discharge stage and nitrogen purging stage after the detection is completed, the controller 3 controls the solenoid valve to remain open, so that waste liquid, waste gas and purging nitrogen can be smoothly discharged through the output pipe 6.

[0074] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An automatic detection device for combustibles in ammonium nitrate, characterized in that, include: Reagent storage unit (1) is used to store ammonium nitrate sample, sodium persulfate reagent and phosphoric acid reagent; The CO2 infrared analyzer (2) is connected to the reagent storage unit (1). The CO2 infrared analyzer (2) is used to receive the reagent supplied by the reagent storage unit (1) so that the sodium persulfate reagent can oxidize the combustibles in the ammonium nitrate sample in the acidic environment formed by the phosphoric acid reagent to generate CO2. The CO2 infrared analyzer (2) is also used to determine the CO2 content and generate content information. The controller (3) is used to control the reagent storage unit (1) to supply reagents to the CO2 infrared analyzer (2) and to receive and analyze the CO2 content information measured by the CO2 infrared analyzer (2) to obtain the combustible content in ammonium nitrate.

2. The automatic detection device for combustibles in ammonium nitrate according to claim 1, characterized in that, Also includes: The CO2 infrared analyzer (2) is connected to the reagent storage unit (1) via the supply component (4), and the controller (3) can control the supply component (4) to supply the reagent in the reagent storage unit (1) to the CO2 infrared analyzer (2).

3. The automatic detection device for combustibles in ammonium nitrate according to claim 2, characterized in that, The reagent storage unit (1) includes: Ammonium nitrate sample bottle (11) is used to store ammonium nitrate samples; Sodium persulfate reagent bottle (12), used for storing ammonium persulfate reagent; Phosphoric acid reagent bottle (13), used for storing phosphoric acid reagent; The feeding assembly (4) has several components, and the ammonium nitrate sample bottle (11), the sodium persulfate reagent bottle (12) and the phosphate reagent bottle (13) are respectively connected to one of the feeding assemblies (4).

4. The automatic detection device for combustibles in ammonium nitrate according to claim 3, characterized in that, The supply component (4) includes: The inlet of the delivery tube (41) is connected to the ammonium nitrate sample bottle (11), the sodium persulfate reagent bottle (12) or the phosphate reagent bottle (13), and the outlet is connected to the CO2 infrared analyzer (2). A self-priming pump (42) is installed on the delivery pipe (41), and the self-priming pump (42) is electrically connected to the controller (3).

5. The automatic detection device for combustibles in ammonium nitrate according to claim 4, characterized in that, The supply component (4) further includes: A flow meter (43) is installed on the delivery pipe (41) and is used to display the flow rate of the delivered reagent; A solenoid valve (44) is installed on the delivery pipe (41) and is used to control the opening and closing of the delivery pipe (41).

6. The automatic detection device for combustibles in ammonium nitrate according to claim 5, characterized in that, The delivery pipe (41) is divided into a suction section (411) and a delivery section (412) from its input end to its output end. The self-priming pump (42), the flow meter (43) and the solenoid valve (44) are all located in the delivery section. The conveying section (412) is a constant diameter section, and the diameter of the suction section (411) gradually decreases along the conveying direction. The suction section (411) is smoothly connected to the conveying section.

7. The automatic detection device for combustibles in ammonium nitrate according to claim 6, characterized in that, The input end of the delivery pipe (41) is smoothly connected to a guide ring (45), and the cross-section of the guide ring (45) is circular.

8. The automatic detection device for combustibles in ammonium nitrate according to claim 4, characterized in that, Also includes: A blow-off pipe (51) is connected to the conveying pipe (41) and is used to blow off residual substances in the conveying pipe (41) to clean the conveying pipe (41). A solenoid valve is provided on the blow-off pipe (51). A nitrogen cylinder (52) is connected to the input end of the purge tube (51) and is used to supply nitrogen to the purge tube (51).

9. The automatic detection device for combustibles in ammonium nitrate according to claim 1, characterized in that, Also includes: The output tube (6) is connected to the CO2 infrared analyzer (2), and the output tube (6) is used to output the substances reacted in the CO2 infrared analyzer (2).

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