Static mixing device and method for continuous production of bulk explosives

Abstract

The application discloses a static mixing device and method for continuous production of expanded explosive, and belongs to the technical field of industrial explosive production. The core of the device is that a static mixer is completely used to replace a dynamic mixer, and a traditional screw pump is cancelled, and only a pressure difference formed by positive pressure provided by a water phase pump and negative pressure provided by a crystallization machine is used as a unique power source for material mixing and conveying. The method comprises the following steps: system preheating, negative pressure establishment, time sequence control of oil phase and water phase feeding, and closed loop control based on pressure difference feedback. The application fundamentally eliminates the safety hidden danger caused by dynamic rotating parts, significantly improves the intrinsic safety level of the production line, and simultaneously achieves the comprehensive effects of reducing energy consumption, reducing maintenance cost and guaranteeing product quality stability.

Description

Technical Field

[0001] This invention relates to the field of industrial explosives production equipment technology, specifically to a static mixing device for the continuous production of expanded ammonium nitrate explosives and a mixing method using the device. Background Technology

[0002] As an important type of industrial explosive, the safety and efficiency of the production process of expanded ammonium nitrate explosives have always been a focus of industry attention. For example... Figure 1 As shown, in current production processes, the mixing of the aqueous phase (mainly ammonium nitrate solution) and the oil phase (fuel oil, etc.) is a crucial step, commonly accomplished using a dynamic water-oil phase mixer in conjunction with a screw pump. The dynamic mixer achieves shear mixing of materials through mechanical rotation, while the screw pump is responsible for pumping the mixed material to the crystallizer for subsequent expansion and crystallization. Although this process is widely used, it has significant drawbacks.

[0003] According to GB44504-2024 "Hazard Categories and Service Life of Special Production Equipment for Civil Explosives", the rotation speed of dynamic mixers used in the production of expanded ammonium nitrate explosives must be controlled below 200 r / min. However, the high-speed rotating internal components inevitably bring hidden dangers such as mechanical friction and localized overheating, posing a potential threat to production safety. More importantly, the screw pump used in conjunction with the equipment is classified as Class 0 equipment in the classification of special equipment for civil explosives, with an extremely high risk factor, and has become one of the main sources of risk on the production line.

[0004] In addition, this equipment combination also suffers from problems such as high energy consumption, frequent maintenance, and high operating costs.

[0005] In recent years, to improve intrinsic safety, the industry has actively explored the application of static mixing technology, such as using static mixers to premix the water-oil phase. However, a search of existing technologies reveals that solutions such as those represented by Chinese patent CN203095905U, while introducing a static mixing structure, still rely on mechanical pumps for power and require dynamic emulsifiers for the refining process, thus failing to fundamentally eliminate high-speed moving parts. Another US patent, US04948440A, also discloses a system for preparing emulsion explosives using a static mixer, but its material transport still relies on power provided by a mechanical pump.

[0006] Therefore, developing a continuous production process that can completely eliminate screw pumps, rely entirely on the system's own pressure to achieve stable material transport, and at the same time ensure mixing effect and final explosion performance remains a technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0007] The present invention aims to overcome the above-mentioned drawbacks of the prior art, and solve the technical problems of low safety, high risk, high energy consumption and high maintenance cost caused by the combination of a dynamic mixer and a screw pump. The main object of the present invention is to provide a continuous production scheme for expanded explosive which completely eliminates the mechanical pumping link, realizes conveying only relying on the pressure difference of the system itself, and ensures the mixing effect and product quality. The specific scheme is as follows: In one aspect, the present invention provides a static mixing device for continuous production of expanded explosive, comprising an aqueous phase supply unit, an oil phase supply unit, a mixing unit, a conveying unit and a crystallization unit; The mixing unit is a static mixer, the inlet end of which is respectively connected with the outlets of the aqueous phase supply unit and the oil phase supply unit; The conveying unit is a conveying pipeline connecting the outlet of the static mixer and the feed inlet of the crystallization unit; The conveying unit does not contain any mechanical pump for pumping the mixed material; The aqueous phase supply unit includes an aqueous phase pump providing conveying power; The crystallization unit is configured to be capable of providing a negative pressure environment; The positive pressure provided by the aqueous phase pump and the negative pressure provided by the crystallization unit together constitute the only power source for conveying the mixed material from the static mixer to the crystallization unit.

[0008] Preferably, the aqueous phase supply unit further comprises an aqueous phase pipeline and an aqueous phase three-way valve; The oil phase supply unit further comprises an oil phase pipeline and an oil phase three-way valve; Both the aqueous phase three-way valve and the oil phase three-way valve include a feeding station and a reflux station, which are used for switching materials to the static mixer or a reflux branch.

[0009] Preferably, the static mixer and the conveying pipeline together form a heat preservation circuit; a temperature transmitter and a pressure transmitter are arranged on the conveying pipeline.

[0010] Preferably, a controller is further included, and the controller is electrically connected with the temperature transmitter, the pressure transmitter, the aqueous phase pump, the oil phase pump and the vacuum pump of the crystallization unit.

[0011] Preferably, the static mixer is installed above the silo position and arranged in the horizontal direction.

[0012] In another aspect, the present invention also provides a static mixing method using the above device, comprising the following steps: S1. Preheat the static mixer and the conveying pipeline, and switch the aqueous phase and the oil phase to a reflux state; S2. Start the crystallization unit and its vacuum pump to establish a negative pressure environment; S3. Switch the oil phase to feed the static mixer; S4. After a delay, switch the aqueous phase to feed the static mixer; S5. Using the positive pressure of the water phase pump and the negative pressure of the crystallization unit, the mixed material is transported to the crystallization unit.

[0013] Preferably, the delay time in step S4 is 3 to 4 seconds; The method further includes: when the temperature transmitter or pressure transmitter detects a value exceeding a preset range, automatically switching the aqueous phase and oil phase back to reflux state.

[0014] Preferably, the method further includes: Real-time monitoring of the pressure at the outlet of the static mixer and the pressure inside the crystallization unit; Based on the pressure difference between the two, the speed of the aqueous phase pump and / or the speed of the vacuum pump are dynamically adjusted to maintain the pressure difference within a stable range.

[0015] Preferably, before supplying the oil phase to the static mixer, the oil phase pipeline is independently heated and insulated.

[0016] Preferably, the system startup sequence is from downstream equipment to upstream equipment, that is, the crystallization unit is started first, then the oil phase supply is started, and finally the aqueous phase supply is started. The system shutdown sequence is from upstream devices to downstream devices.

[0017] Compared with existing technologies, this invention completely replaces the traditional dynamic mixer with a static mixer and innovatively utilizes the positive pressure of the aqueous phase pump and the negative pressure of the crystallizer to form the conveying power, thus completely eliminating the high-risk screw pump. This fundamentally eliminates the ignition risk that may be caused by mechanical rotation and friction, significantly improving the inherent safety level of the production process and perfectly meeting the urgent needs of the civil explosives industry for "unmanned, intelligent, and inherently safe" processes. Furthermore, by eliminating the high-energy-consuming screw pump, the overall system's energy consumption is significantly reduced. The simplified equipment structure also leads to a lower failure rate and reduced maintenance workload, effectively lowering long-term operating costs. Most importantly, actual production line testing has verified that this technical solution, while ensuring safety and efficiency, does not sacrifice product quality. The produced expanded nitric acid and expanded explosives exhibit key performance indicators such as initial bulk density, component content, explosive properties such as saturation, sympathetic detonation distance, and detonation velocity, which are comparable to those of products produced using traditional processes, fully complying with relevant national standards. Meanwhile, by integrating pressure and temperature sensors with an intelligent controller, this invention also enables real-time monitoring and automatic control of the system's operating status. This not only ensures the stability of the conveying pressure differential and the uniform mixing of materials, but also provides automatic fault diagnosis and safety interlock protection functions, greatly enhancing the continuity and reliability of production. Overall, it promotes the development of puffed explosive production lines towards a safer, more economical, and more intelligent direction. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 This is a schematic diagram of a dynamic water-oil phase mixing device in the traditional industrial explosives production process. Figure 2 A schematic diagram of the improved static mixing device for continuous production of expanded explosives according to the present invention; In the diagram: 1. Static mixer; 2. Aqueous phase pipeline; 3. Oil phase pipeline; 4. Crystallizer; 5. Stirring motor. Detailed Implementation

[0020] This invention aims to provide a technical transformation solution for an expanded ammonium nitrate explosive production line that is inherently safer, consumes less energy, and is easier to maintain. Its core lies in abandoning the traditional combination of a dynamic mixer and screw pump, replacing it with a static mixer 1 and utilizing the inherent pressure difference of the system as the conveying power. The following two embodiments illustrate the device structure and method flow of this invention in detail. These embodiments are merely illustrative and not intended to limit the scope of the invention.

[0021] Example 1: This embodiment provides a static mixing device for the continuous production of expanded explosives, which systematically integrates material supply, mixing, conveying, crystallization and control functions.

[0022] The core of the aqueous phase supply unit is the aqueous phase pump, whose inlet leads to an aqueous phase storage tank preheated to approximately 126°C, and whose outlet extends through aqueous phase pipeline 2. Downstream of the aqueous phase pump, an aqueous phase three-way valve is installed on aqueous phase pipeline 2. One outlet of this valve leads to downstream equipment, while the other outlet connects to a return branch. This return branch ultimately returns the material to the aqueous phase storage tank or a dedicated return receiving tank, thus enabling flexible switching between the feeding and recirculation modes of the aqueous phase material.

[0023] The oil phase supply unit is structurally symmetrical and independent of the water phase supply unit. It includes an oil phase pump, an oil phase pipeline 3, and an oil phase three-way valve with the same function. This three-way valve is also connected to the aforementioned shared or another independent return branch to control the flow direction of the oil phase material. It is worth noting that a steam valve can also be added to the oil phase pipeline 3 to allow steam to be introduced to independently insulate the pipeline, ensuring that the oil phase temperature is stably maintained at, for example, around 71°C, to prevent the oil phase from solidifying or becoming less fluid due to excessively low temperature.

[0024] The core component of the mixing unit is the static mixer 1, which is preferably an SH type or similar model with a series of fixed mixing elements inside. These mixing elements are arranged according to a specific geometric structure, and when the fluid flows through them, they are repeatedly divided, rotated, and recombined, thereby achieving uniform mixing of materials through laminar flow segmentation and turbulent disturbance. The dispersion degree is high and the mixing effect is excellent. The two inlets of the static mixer 1 are respectively connected to the main output end of the water phase pipeline 2 and the oil phase pipeline 3 through flange connections, after the return flow path of the three-way valve is cut off, so as to receive materials from the water phase supply unit and the oil phase supply unit.

[0025] The conveying unit consists of a conveying pipeline connecting the outlet of the static mixer 1 to the inlet of the crystallization unit. Throughout the entire material conveying process, from the outlet flange of the static mixer 1 to the inlet of the crystallization unit, no mechanical pumps of any kind are used to pump the mixed material; positive displacement pumps such as screw pumps, gear pumps, or plunger pumps are completely eliminated. Optionally, to ensure that the high-temperature mixed material does not crystallize and clog the pipeline due to temperature drop during conveying, the entire body of the static mixer 1 and its outlet conveying pipeline are tightly wrapped with a complete insulation circuit. This insulation circuit can be in the form of a jacketed circuit with heat transfer oil or steam, or it can be tightly wrapped with high-performance insulation material. Its purpose is to continuously heat and / or insulate the mixed material. Near the outlet of the static mixer 1, key sensors for real-time monitoring of the material's state, such as temperature transmitters and pressure transmitters, are installed on the conveying pipeline. Their probes extend into the pipeline to directly contact the material, and are used to collect the instantaneous temperature and pressure values ​​of the mixed material, respectively.

[0026] The crystallization unit is a key piece of equipment for receiving and expanding the mixture into crystals; it is essentially a large vacuum crystallizer 4. Its inlet is connected to the end of the aforementioned conveying pipeline via a flange. A water-ring vacuum pump is connected to the crystallization unit via a pipeline. This pump operates continuously to establish and maintain a stable negative pressure environment within the internal cavity of the crystallization unit, preferably maintaining the absolute pressure at a level of approximately -0.079 MPa to -0.08 MPa. This negative pressure environment is not only the process condition required for the expansion and crystallization of the material, but more importantly, it, together with the approximately 0.15 MPa positive pressure provided by the aqueous phase pump, forms a pressure gradient across the static mixer 1 to the crystallization unit. This pressure difference—the difference between the positive pressure of the aqueous phase pump and the negative pressure of the crystallization unit—becomes the sole power source propelling the mixture from the static mixer 1 to the crystallization unit, completely replacing the mechanical pumping action of the screw pump in traditional solutions.

[0027] Finally, the entire unit is intelligently monitored and controlled by a centralized controller. This controller can be a PLC or DCS system, and is electrically connected via cables to temperature transmitters, pressure transmitters, frequency converters for the water phase pump, oil phase pump, and water ring vacuum pump, as well as the actuators for the water phase three-way valve, oil phase three-way valve, and steam valve on oil phase pipeline 3. The controller has pre-stored various process parameter settings and safety thresholds. It receives detection signals from various sensors in real time and outputs control commands according to its built-in program logic, thereby coordinating the automatic operation of the entire system and realizing functions such as start-stop sequence control, flow regulation, pressure balance control, and fault safety interlocking.

[0028] To verify the actual operating effect and product performance of the device described in this embodiment, a modification and test were conducted on a standard rock-expanded ammonium nitrate explosive production line. The test strictly followed the specifications in the "Safety Technical Operation Procedures for the Production of Rock-Expanded Ammonium Nitrate Explosives" (A3). The key process parameters used in the test were set and monitored through the control system, and their specific values ​​are recorded in Table 1 below. These parameters ensured that the materials were effectively mixed in the static mixer 1 and stably conveyed in the conveying pipeline. Table 1. Production Line Trial Operation Parameters

[0029] The specific operating procedure of this device is as follows: Before system startup, firstly, the insulation circuit is activated to fully preheat the static mixer 1 and its outlet conveying pipeline to prevent material solidification caused by cold feeding. Simultaneously, the controller switches both the aqueous phase three-way valve and the oil phase three-way valve to the reflux position, allowing the aqueous and oil phase materials to circulate within their respective supply units. After preheating, following the safe startup sequence from downstream to upstream, first start the stirring motor 5 of the crystallization unit, then start the water ring vacuum pump. Once the vacuum level in the crystallization unit stabilizes and reaches the negative pressure value required by the process, start the oil phase supply, i.e., switch the oil phase three-way valve to the feeding position to the static mixer 1. After approximately 3-4 seconds, switch the aqueous phase three-way valve back to the feeding position.

[0030] Subsequently, the mixture is smoothly transported to the crystallization unit for expansion and crystallization under the combined action of the positive pressure from the aqueous phase pump and the negative pressure from the crystallization unit. During operation, the controller continuously monitors the static mixer 1 outlet pressure fed back by the pressure transmitter and the pressure within the crystallization unit, and dynamically adjusts the speed of the aqueous phase pump and the water ring vacuum pump to maintain the delivery pressure difference within a stable range. If the temperature transmitter detects that the temperature is below the set lower limit or the pressure transmitter detects abnormal pressure fluctuations, the controller will immediately switch the three-way valve back to the reflux state, interrupting the feed and ensuring safety. When shutting down, the reverse sequence is followed: first, stop the aqueous and oil phase feeds and switch to reflux; then, shut down the water ring vacuum pump and the crystallization unit; finally, shut down the insulation circuit.

[0031] Through practical application verification, the inherent safety of the mixing device has been improved like never before. By completely eliminating the high-speed rotating dynamic mixer and the screw pump, which is classified as a Class 0 high-risk device, the risk sources of mechanical friction, impact-induced sparks and overheating have been fundamentally eliminated. This means that no dynamic mechanical parts are involved in the entire mixing and conveying process, which fully meets the ultimate pursuit of inherent safety in the civil explosives industry.

[0032] Secondly, it demonstrates outstanding economic benefits. Eliminating the screw pump and its drive motor directly reduces equipment procurement costs and operating energy consumption. The simplified system structure also reduces daily maintenance points and significantly lowers the failure rate, thereby saving a significant amount of maintenance manpower and material costs.

[0033] Furthermore, after rigorous production line comparison tests, a comprehensive performance comparison was conducted between products produced using this equipment and products produced using traditional processes. The results are shown in Tables 2 and 3 below: Table 2. Performance Comparison of Expanded Nitric Acid

[0034] Table 3. Comparison of the properties of expanded explosives

[0035] The data in Tables 2 and 3 show that the expanded nitric acid and expanded explosives produced using this equipment exhibit highly consistent performance across all key indicators, including initial bulk density, final bulk density, composition of ammonium nitrate, oil phase, and wood flour, as well as explosive performance parameters such as saturation, sympathetic detonation distance, and detonation velocity, compared to products produced using traditional processes. All indicators fully meet or even exceed the requirements of relevant national standards, demonstrating that product quality has not been sacrificed in the slightest while ensuring safety. Finally, its high level of automation and intelligence is unparalleled by traditional systems. The integrated control system enables real-time, precise monitoring and automatic adjustment of the production process, significantly reducing manual intervention and potential errors, and greatly enhancing the continuity, stability, and reliability of production operations.

[0036] Example 2: This embodiment provides a static mixing method for the continuous production of expanded ammonium nitrate explosives, which is implemented based on the apparatus described in Embodiment 1. First, the system is preheated. The operator or controller automatically activates the insulation circuit surrounding the static mixer 1 and its outlet delivery pipeline, raising and maintaining the temperature of this critical path above a level sufficient to prevent ammonium nitrate crystallization. Simultaneously, the controller outputs commands to set both the aqueous phase three-way valve and the oil phase three-way valve to the reflux position. This ensures that the aqueous and oil phase materials pumped from the aqueous and oil phase pumps do not enter the static mixer 1, but instead return to their respective storage tanks through their connected reflux branches, forming a cyclic preheating process. This step ensures that all surfaces in contact with the materials reach the process temperature, preparing for formal feeding.

[0037] After preheating reaches the required level, the method enters the pressure establishment phase. This phase strictly follows the safe startup sequence from downstream equipment to upstream equipment to prevent material accumulation upstream before downstream equipment is ready. First, the crystallization unit's own stirring motor 5 is started to run under no-load. Then, the frequency converter associated with the water ring vacuum pump is immediately started. The water ring vacuum pump begins to work, quickly establishing and maintaining a high vacuum level within the sealed cavity of the crystallization unit, i.e., the required negative pressure environment. Its absolute pressure value is monitored by instruments and fed back to the controller to ensure that it reaches, for example, a predetermined range of -0.079 MPa to -0.08 MPa. The successful establishment of this negative pressure environment is a prerequisite for subsequent material transport using pressure differential.

[0038] Next, the method enters the crucial timing-based feeding and mixing stage. After confirming the stability of the negative pressure in the crystallization unit, the controller first sends a command to change the position of the oil phase three-way valve, switching it from the reflux state to a state that allows the oil phase material to flow into the inlet of static mixer 1. At this time, the oil phase pump continues to operate, pumping the oil phase, maintained at approximately 71°C, into static mixer 1 at a stable flow rate, for example, 110.8 kg / h. An important timing control point is that after the oil phase begins to enter static mixer 1, the controller waits for a preset delay time, usually set between 3 and 4 seconds. After this short delay, a command is issued to switch the aqueous phase three-way valve to the feeding position, resulting in a temperature of approximately 126°C and a concentration of approximately 1.423 g / cm³. 3 The aqueous phase material is pumped into the static mixer 1 at a much higher flow rate, for example, 3003 kg / h, and a pressure of approximately 0.15 MPa. This feed sequence design, with the oil phase preceding the aqueous phase and a short time delay, facilitates the formation of a lubricating film in the initial section of the static mixer 1, reducing the risk of subsequent high-concentration aqueous phase material adhering to the walls and crystallizing, and ensuring more uniform mixing of the two phases within the static mixer 1. As the two phases flow through the fixed mixing elements inside the static mixer 1, they are efficiently separated, sheared, rotated, and recombined. Through intense laminar flow separation and turbulent disturbance, a homogeneous mixture is formed in a very short time.

[0039] The next step is the core of the method: differential pressure conveying and closed-loop control. After thorough mixing, the material flows out of the static mixer 1 and into the conveying pipeline. At this point, the sole driving force propelling it towards the crystallization unit is neither gravity nor an additional mechanical pump, but rather the net driving pressure difference created by the combined effect of the positive pressure provided by the aqueous phase pump and the negative pressure maintained inside the crystallization unit. This pressure difference must be precisely controlled and stably maintained to ensure stable flow and prevent flow interruptions or blockages.

[0040] To this end, the controller continuously and in real time acquires two key pressure signals: one is the pressure value of the mixed material measured by a pressure transmitter installed near the outlet of static mixer 1, and the other is the absolute pressure value fed back by the pressure monitoring instrument inside the crystallization unit. The core control algorithm of the controller continuously calculates the difference between these two pressures, i.e., the actual delivery pressure difference. This real-time pressure difference is compared with a preset, optimal stable pressure difference range; if the real-time pressure difference deviates from this range, the controller will immediately output an adjustment signal, dynamically and slightly adjusting the output frequency of the inverter of the water phase pump and / or the inverter of the water ring vacuum pump. By changing the discharge pressure of the water pump or the vacuum degree of crystallizer 4, the controller reverses the pressure difference change to compensate for it, thereby stably maintaining it within the target range, for example, maintaining the outlet pressure of static mixer 1 at about -0.033 MPa. This closed-loop control strategy based on pressure difference feedback is the key technical guarantee for the smooth operation of the entire method.

[0041] In addition, optionally, the method of this embodiment also includes a comprehensive safety monitoring and fault handling mechanism. Throughout the feeding and conveying process, the temperature transmitter continuously monitors the temperature of the mixture to ensure it is well above the crystallization point. Once the controller detects that the temperature data from the temperature transmitter is below the safety threshold, or that the pressure data from the pressure transmitter fluctuates drastically or exceeds the preset safety range, it will immediately determine an abnormal situation, such as a possible precursor to crystallization blockage. The controller will immediately trigger the safety interlock without hesitation: first, it will output a command to quickly switch the aqueous phase three-way valve and the oil phase three-way valve back to the reflux position, cutting off the material flow to the static mixer 1; at the same time, it will keep the insulation circuit working to prevent the temperature from dropping further; the system will enter a safety hold state, waiting for operator intervention and inspection. Only after the fault is eliminated and the parameters return to normal can the feeding sequence be restarted according to the established procedure. For the oil phase pipeline 3, its independent temperature control requirements are also fully considered. Before feeding and throughout the production process, the steam valve added to the oil phase pipeline 3 can be opened as needed to provide additional heating to the oil phase independently of the main insulation circuit to ensure its fluidity. The controller can set the oil phase temperature threshold and lock the feeding operation to the static mixer 1 before the oil temperature reaches the standard.

[0042] Finally, there is the orderly shutdown phase of the system. When production needs to be stopped, the method specifies a shutdown sequence from upstream to downstream: the controller first stops the operation of the aqueous phase pump and the oil phase pump, then switches the aqueous phase three-way valve and the oil phase three-way valve back to the reflux position to cut off the material source; after this, the operation of the crystallization unit's stirring motor 5 and the water ring vacuum pump is stopped in sequence; after the main equipment stops, the heating function of the insulation circuit is finally turned off. This shutdown sequence ensures that no material residue cools and causes blockage in the system.

[0043] During the test, the control system accurately executed the above steps, especially in the differential pressure transmission and closed-loop control stages. Based on the pressure feedback from the pressure transmitter and the crystallization unit, the controller dynamically adjusted the frequency of the aqueous phase pump and the water ring vacuum pump, successfully stabilizing the system under the operating parameters listed in Table 1. The aqueous phase flow rate was stabilized at 3003 kg / h, the oil phase flow rate was stabilized at 110.8 kg / h, and the outlet pressure of static mixer 1 was maintained at approximately -0.033 MPa.

[0044] The final product underwent sampling and rigorous testing, and its performance fully met expectations. For detailed performance data, please refer to Tables 2 and 3 in Example 1.

[0045] In addition, Table 4 below shows the changes in operating parameters of oil phase pumps and water phase pumps under different production capacities, which fully demonstrates that the method has good adaptability to operating conditions and control stability.

[0046] Table 4. Parameters of oil phase pump and water phase pump at different production capacities

[0047] The implementation effect of this method and the effect of the device complement each other, jointly demonstrating the superiority of this invention. By strictly following the above steps, this method successfully transforms device design into stable and reliable production capacity. The preset start-up and shutdown sequence, timing control, and safety interlock logic minimize human error and equipment malfunction, reducing potential risks to a minimum. Secondly, this method demonstrates excellent production stability and quality control capabilities. The closed-loop control algorithm based on real-time differential pressure feedback can effectively resist external interference and maintain a high degree of stability in material conveying flow. This not only ensures continuous production but is also an important prerequisite for the high uniformity of the final product performance. The comparative test data in Tables 2 and 3 of Example 1 fully confirm that the products produced by this method are no different from traditional products in all key indicators such as bulk density, component content, and explosive performance. At the same time, this method achieves a high degree of automation and intelligence, freeing operators from tedious manual adjustment and monitoring. The controller integrates the monitoring of all key parameters and the control of actuators, forming an organic whole. This not only improves production efficiency but also gives the production line the ability to quickly adapt to abnormal working conditions, comprehensively promoting the technological advancement of expanded explosive production processes.

Claims

1. A static mixing device for continuous production of expanded explosives, comprising an aqueous phase supply unit, an oil phase supply unit, a mixing unit, a conveying unit, and a crystallization unit, characterized in that: The mixing unit is a static mixer (1), whose inlet end is connected to the outlet of the water phase supply unit and the oil phase supply unit respectively; The conveying unit is a conveying pipeline connecting the outlet of the static mixer (1) and the inlet of the crystallization unit; The conveying unit does not contain any mechanical pumps for pumping the mixed materials; The water phase supply unit includes a water phase pump that provides power for the transport. The crystallization unit includes a water ring vacuum pump that provides a negative pressure environment; The positive pressure provided by the water phase pump and the negative pressure provided by the crystallization unit together constitute the sole power source for transporting the mixture from the static mixer (1) to the crystallization unit.

2. The static mixing device for continuous production of expanded explosives according to claim 1, characterized in that: The water phase supply unit also includes a water phase pipeline (2) and a water phase three-way valve; The oil phase supply unit also includes an oil phase pipeline (3) and an oil phase three-way valve; Both the water phase three-way valve and the oil phase three-way valve include a feed station and a return station, used to switch the material to the static mixer (1) or to a return branch.

3. The static mixing device for continuous production of expanded explosives according to claim 2, characterized in that: The static mixer (1) and the conveying pipeline together form a heat preservation circuit; a temperature transmitter and a pressure transmitter are provided on the conveying pipeline.

4. The static mixing device for continuous production of expanded explosives according to claim 3, characterized in that: It also includes a controller, which is electrically connected to the temperature transmitter, pressure transmitter, water phase pump, oil phase pump, and water ring vacuum pump of the crystallization unit.

5. A static mixing method using the apparatus described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Preheat the static mixer (1) and the delivery pipeline, and switch the water phase and oil phase to reflux state; S2. Start the crystallization unit and its water ring vacuum pump to establish a negative pressure environment; S3. Switch the oil phase to feed the static mixer (1); S4. After a delay, switch the aqueous phase to feed the static mixer (1); S5. Using the positive pressure of the water phase pump and the negative pressure of the crystallization unit, the mixed material is transported to the crystallization unit.

6. The static mixing method for continuous production of expanded explosives according to claim 5, characterized in that: The delay time in step S4 is 3 to 4 seconds; The method further includes: when the temperature transmitter or pressure transmitter detects a value exceeding a preset range, automatically switching the aqueous phase and oil phase back to reflux state.

7. The static mixing method for continuous production of expanded explosives according to claim 5, characterized in that, The method further includes: Real-time monitoring of the pressure at the outlet of the static mixer (1) and the pressure inside the crystallization unit; Based on the pressure difference between the two, the rotational speed of the aqueous phase pump and / or the rotational speed of the water ring vacuum pump are dynamically adjusted to maintain the pressure difference within a stable range.

8. The static mixing method for continuous production of expanded explosives according to claim 5, characterized in that: Before supplying the oil phase to the static mixer (1), the oil phase pipeline (3) is independently heated and insulated.

9. The static mixing method for continuous production of expanded explosives according to claim 5, characterized in that: The system startup sequence is from downstream equipment to upstream equipment, that is, first start the crystallization unit, then start the oil phase supply, and finally start the aqueous phase supply; The system shutdown sequence is from upstream devices to downstream devices.

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