Extraction system capable of monitoring temperature of extract liquor in real time

Abstract

The invention discloses an extraction system capable of monitoring the temperature of extract liquor in real time, and belongs to the technical field of chemical experiment equipment. The system solves the problems of large deviation and inaccuracy caused by the fact that an existing Soxhlet extraction device adopts a single-neck round-bottom flask and cannot directly monitor the temperature of extract liquor and only indirect temperature measurement is adopted. According to the technical scheme, a multi-neck round-bottom flask is adopted to replace a single-neck flask, a first neck part of the multi-neck round-bottom flask is connected with an extraction tube, a second neck part is provided with a temperature sensor through a ground port, and a sensing part of the sensor extends into the flask and is immersed in an extraction solution. According to the system, thermal resistance of a bottle wall is avoided through direct contact type temperature measurement, accurate real-time monitoring is realized, and the system is used for accurately controlling heating, stabilizing temperature and improving efficiency and reliability in a chemical extraction experiment.

Description

An extraction system capable of real-time monitoring of the extractant temperature Technical Field

[0001] This invention belongs to the field of chemical experimental equipment technology, specifically relating to an extraction system that can monitor the temperature of the extraction solution in real time. Background Technology

[0002] In the field of chemical analysis and sample pretreatment, Soxhlet extraction is a commonly used extraction technique. Its core equipment typically includes an extraction tube, a condenser, a heating mantle, and a round-bottom flask. Accurate knowledge and control of the temperature of the extractant inside the round-bottom flask are crucial in this system, as they directly affect extraction efficiency, solvent recovery rate, and the extraction effect of the target component. However, temperature monitoring faces practical difficulties in existing typical setups. The common practice is to indirectly infer the temperature of the extractant by measuring the heating temperature of the heating mantle or the temperature of the outer wall of the round-bottom flask. This method has inherent inaccuracies. Because heat is transferred from the heating mantle to the flask wall, and then through the flask wall and any air gaps, to the extractant, the entire process involves multiple thermal resistances, resulting in a significant difference between the flask wall temperature and the actual internal liquid temperature. This temperature difference is affected by various factors such as ambient temperature, heating power, liquid volume, and boiling state, making it difficult to reliably compensate for using simple empirical formulas.

[0003] Therefore, operators cannot obtain the true real-time temperature of the extract, which hinders precise control of the extraction process. For example, in experimental conditions requiring the maintenance of a slight boiling of the solvent or a specific extraction temperature, the lag and inaccuracy of indirect temperature measurement may lead to improper adjustment of heating power. Too low a temperature will reduce the extraction rate and prolong the experimental time; too high a temperature may cause excessive solvent evaporation, decomposition of the target component, or the risk of bumping. Attempting to place the temperature sensor directly inside the round-bottom flask also faces technical challenges. A standard single-necked round-bottom flask has only one neck for connecting the extraction tube; installing a sensor here would occupy the only connection channel, preventing the system from functioning properly. Additional openings or the use of non-standard interfaces may introduce poor sealing, leading to solvent vapor leakage, causing solvent loss, environmental pollution, potential safety hazards, and disrupting the airtight balance of the extraction reflux system. Furthermore, uncertain fixed positions and depths of the sensor inside the flask can result in poor comparability of measurements, failing to provide stable and reliable temperature data. These factors collectively make it practically difficult to achieve accurate, direct, and real-time monitoring of the extract temperature inside the round-bottom flask within the existing technological framework. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0005] Another objective of this invention is to provide an extraction system capable of real-time monitoring of the extraction solution temperature. This system effectively avoids temperature measurement lag and distortion caused by the thermal resistance of the flask wall by directly inserting and immersing the sensing part of the temperature sensor into the extraction solution inside the round-bottom flask. This enables accurate and real-time monitoring of the true temperature of the extraction solution, providing a reliable basis for precise control of the heating process, helping to maintain stable extraction temperature conditions, and improving extraction efficiency and the reliability of experimental results.

[0006] To achieve these objectives and other advantages of the present invention, an extraction system capable of real-time monitoring of the extractant temperature is provided, comprising an extraction tube, a condenser, a heating mantle, a round-bottom flask, and a monitoring system. One end of the extraction tube is connected to the condenser, and the other end of the extraction tube is connected to the round-bottom flask. The heating mantle is fitted over the lower part of the round-bottom flask for heating the flask. The round-bottom flask is characterized by being a multi-necked round-bottom flask with at least two necks. The first neck of the multi-necked round-bottom flask is connected to the extraction tube via a ground glass joint. The second neck of the multi-necked round-bottom flask has a standard ground glass joint interface, and a temperature sensor is mounted on the second neck via the standard ground glass joint interface. The temperature sensor includes a sensing element and a signal transmission line. The upper end of the sensing element is sealed to the standard ground glass joint interface via a ground glass adapter. The lower end of the sensing element extends into the internal space of the round-bottom flask, with its end located 10 mm to 100 mm above the bottom of the round-bottom flask. The signal transmission line extends from the sensing element for connecting to the monitoring system.

[0007] Preferably, the monitoring system includes a signal receiving module, a data processing module, and a control signal output module; the signal receiving module is connected to the signal transmission line of the temperature sensor and is used to receive temperature signals; the data processing module has a preset temperature threshold range and compares the real-time temperature signal received by the signal receiving module with the temperature threshold range; the control signal output module is connected to the power circuit of the heating mantle; when the real-time temperature signal is lower than the lower limit of the temperature threshold range, the control signal output module outputs a signal to increase the heating power of the heating mantle or turn on its heating circuit; when the real-time temperature signal is higher than the upper limit of the temperature threshold range, the control signal output module outputs a signal to decrease the heating power of the heating mantle or turn off its heating circuit.

[0008] Preferably, the monitoring system further includes a network communication module; the network communication module is connected to the data processing module and is used to send the real-time temperature signal, the temperature threshold range, and the working status data of the electric heating mantle to a remote terminal via a wireless network, and to receive control commands from the remote terminal; the control commands include commands to modify the temperature threshold range, commands to start the electric heating mantle, and commands to stop the electric heating mantle; the data processing module is also used to update the internal temperature threshold range according to the received control commands, or to send corresponding start / stop signals to the control signal output module.

[0009] Preferably, the data processing module further includes a communication status monitoring unit and a local security policy unit; the communication status monitoring unit continuously monitors the communication link status between the network communication module and the remote terminal; the local security policy unit has a preset security operation procedure, which is activated when the following two conditions are met simultaneously: first, the communication status monitoring unit detects that the duration of the communication interruption reaches a first preset time threshold; second, the real-time temperature signal received by the data processing module exceeds the upper limit of the temperature threshold range; when the security operation procedure is activated, the local security policy unit takes over the control of the control signal output module and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to zero within a time period of 30 seconds to 300 seconds.

[0010] Preferably, the data processing module further includes a sensor diagnostic unit; the sensor diagnostic unit is connected to the signal receiving module and is used to perform periodic or continuous diagnostics on the temperature sensor; the diagnostics include monitoring the impedance value of the temperature sensor signal transmission line loop and comparing the impedance value with a preset normal impedance range; when the impedance value continuously exceeds the normal impedance range to a second preset time threshold, the sensor diagnostic unit determines that the temperature sensor has an open circuit or short circuit fault and generates a sensor fault signal; the local safety policy unit also has a preset sensor fault response program; when the sensor diagnostic unit generates the sensor fault signal, the sensor fault response program is activated, the local safety policy unit then takes over control and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to a preset safe heat preservation power value or zero within 10 to 60 seconds.

[0011] Preferably, the extraction system further includes a local audible and visual alarm, which is electrically connected to the data processing module; after generating the sensor fault signal, the sensor diagnostic unit simultaneously sends the signal to the local security strategy unit and the local audible and visual alarm; upon receiving the sensor fault signal, the local audible and visual alarm is triggered and emits a continuous audible and visual warning signal; the audible and visual warning signal remains active during the duration of the sensor fault signal; the audible and visual warning signal is automatically deactivated after the sensor diagnostic unit detects that the impedance value has recovered to the normal impedance range and remains within a third preset time threshold.

[0012] Preferably, the data processing module is also connected to a non-volatile memory, which pre-stores a solvent boiling point database. The solvent boiling point database contains identification information of various common solvents and their corresponding standard boiling point data. The data processing module is configured to: receive the identification information of a target solvent specified by the user through an input device; query the solvent boiling point database according to the identification information to obtain the corresponding standard boiling point data; and automatically calculate and set the temperature threshold range based on the standard boiling point data, wherein the upper limit of the temperature threshold range is set to a value 5°C to 15°C lower than the standard boiling point data, and the lower limit of the temperature threshold range is set to a value 15°C to 30°C lower than the standard boiling point data.

[0013] Preferably, the monitoring system further includes a liquid level status judgment module, which is configured to: continuously record real-time temperature data measured by the temperature sensor and calculate its rate of change over time; and compare the real-time temperature data with a preset warning temperature value T. alert In comparison, the warning temperature value is 10°C to 20°C lower than the boiling point of the solvent used in the extraction; when the real-time temperature data reaches or exceeds the warning temperature value T within a continuous first time period Δt1. alert Furthermore, the calculated rate of temperature change within this Δt1 segment is lower than the preset positive rate of change threshold α. max When the extract level is too low or the solvent is close to being evaporated, it is determined that the extract level is too low or the solvent is close to being evaporated; wherein, Δt1 is 30 seconds to 120 seconds, and α max The speed is 0.1℃ / second to 0.5℃ / second; when it is determined that the liquid level of the extract is too low or the solvent is close to being evaporated, a control command is generated and sent to the control circuit of the heating mantle to reduce the heating power of the heating mantle to a preset safe power value or cut off its heating power supply. The safe power value is 0% to 10% of the rated power.

[0014] Preferably, the liquid level state judgment module is further configured to initiate a re-judgment program after performing the operation of reducing heating power or cutting off power. The re-judgment program includes: maintaining the low power or power-off state for a fourth preset time Δt4, and then controlling the heating mantle to restore the initial heating power; Δt4 is 60 seconds to 300 seconds, and the initial heating power is 10% to 30% of the rated power; continuously monitoring the real-time temperature data and rate of change during the second time period Δt2 after the heating is restored, Δt2 is 60 seconds to 180 seconds; if the temperature data monitored during the Δt2 stage is always lower than the low temperature threshold T of the solvent boiling point. low If the absolute value of the average temperature change rate within Δt2 is less than β, then the extract has been confirmed to have evaporated to dryness; where T low The temperature must be at least 30°C below the solvent boiling point, with β at 0.05°C / second; if the monitored temperature rises within Δt2 and again exceeds the warning temperature value T, the warning temperature will be maintained. alert If the result is incorrect, it is determined to be a misjudgment or a brief boiling over, and the heating mantle is immediately controlled to resume the normal extraction heating process.

[0015] Preferably, the remote terminal is a mobile terminal; the extraction system also includes a camera, which is positioned to capture images of the round-bottom flask and extraction tube, and the camera is connected to the network communication module of the monitoring system; the network communication module also sends the video data collected by the camera to the mobile terminal; the mobile terminal has a monitoring application installed, which provides a user interface for real-time display of received data and video data; the user interface also includes input controls for receiving user control commands, including temperature setting commands and heating mantle start / stop commands; the monitoring application sends the received control commands to the data processing module through the network communication module; the data processing module updates the temperature threshold range according to the temperature setting command, or sends a corresponding control signal to the control signal output module according to the heating mantle start / stop command.

[0016] The present invention has at least the following beneficial effects: First, by immersing the temperature sensor directly into the interior of the extract, the present invention effectively avoids the temperature measurement lag and deviation caused by the thermal resistance of the round-bottom flask wall, and can accurately and in real time obtain the true temperature of the extract, providing a reliable data basis for process monitoring.

[0017] Secondly, based on directly monitored real temperature data, this invention can achieve more precise feedback control of the heating power of the heating mantle, which helps to stabilize the temperature of the extractant within the expected range, thereby improving the extraction efficiency and the consistency of the experiment.

[0018] Third, the present invention adopts a multi-necked round-bottom flask with a sensor installed in its additional neck. While realizing the direct temperature measurement function, it ensures the independence of the extraction pipeline connection and the overall sealing of the system. The structure is reasonable and easy to modify and apply based on existing devices.

[0019] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the structure of the round-bottom flask of the present invention.

[0021] 1. First neck; 2. Second neck. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0023] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0024] An extraction system capable of real-time monitoring of the extractant temperature includes an extraction tube, a condenser, a heating mantle, a round-bottom flask, and a monitoring system. One end of the extraction tube is connected to the condenser, and the other end is connected to the round-bottom flask. The heating mantle is fitted over the lower part of the round-bottom flask for heating it. The round-bottom flask is a multi-necked flask with at least two necks. The first neck of the multi-necked flask is connected to the extraction tube via a ground glass joint. The second neck of the multi-necked flask has a standard ground glass joint interface, through which a temperature sensor is mounted. The temperature sensor includes a sensing element and a signal transmission line. The upper end of the sensing element is sealed to the standard ground glass joint interface via a ground glass adapter. The lower end of the sensing element extends into the internal space of the round-bottom flask, with its end located 10 mm to 100 mm above the bottom of the flask. The signal transmission line extends from the sensing element and is used to connect to the monitoring system.

[0025] In traditional Soxhlet extraction apparatuses, a single-necked round-bottom flask is typically used as the container for solvent heating and extraction. The flask's single neck is used to connect the extraction tube, forming a reflux path. Therefore, temperature monitoring is often achieved by contacting the surface of the heating mantle or the outer wall of the flask. This indirect temperature measurement method suffers from significant thermal resistance and hysteresis because heat must be transferred sequentially through the flask's glass wall and the internal air or liquid. This results in a non-negligible deviation between the measured temperature and the true temperature of the core region of the extract, and this deviation fluctuates with heating power, environmental conditions, and liquid level changes, making it impossible to provide accurate and reliable temperature parameters for the experiment.

[0026] To address the aforementioned issues, this implementation scheme employs a multi-necked round-bottom flask with at least two necks instead of a traditional single-necked flask. One neck, serving as the first neck, is sealed to the extraction tube via a standard ground glass joint, ensuring unobstructed extraction reflux and system airtightness. The other independent neck, serving as the second neck, also features a standard ground glass joint, on which a temperature sensor is securely mounted via a ground glass adapter. The second neck can be positioned anywhere adjacent to the first neck, allowing the temperature sensor to be inserted into the round-bottom flask, provided the flask can hold the liquid solvent. The upper end of the sensing element of the temperature sensor is securely fixed in the adapter, while its lower end extends through the second neck into the internal cavity of the round-bottom flask, ensuring its tip ultimately hangs a distance above the bottom of the flask. This distance is controlled within the range of 10 to 100 millimeters to ensure stable immersion below the extraction liquid surface. The sensor's signal transmission line extends from the sensing element and connects to the monitoring system. This structural design allows the sensing element of the temperature sensor to directly contact the extraction liquid inside the round-bottom flask, bypassing the thermal resistance of the flask wall and enabling direct, real-time sensing of the liquid temperature. The entire sensor installation process utilizes a standard ground glass joint system commonly used in laboratory glassware, ensuring convenient connection and reliable sealing, achieving functional upgrades without complex modifications to existing equipment.

[0027] Furthermore, the monitoring system includes a signal receiving module, a data processing module, and a control signal output module; the signal receiving module is connected to the signal transmission line of the temperature sensor and is used to receive temperature signals; the data processing module has a preset temperature threshold range and compares the real-time temperature signal received by the signal receiving module with the temperature threshold range; the control signal output module is connected to the power circuit of the heating mantle; when the real-time temperature signal is lower than the lower limit of the temperature threshold range, the control signal output module outputs a signal to increase the heating power of the heating mantle or turn on its heating circuit; when the real-time temperature signal is higher than the upper limit of the temperature threshold range, the control signal output module outputs a signal to decrease the heating power of the heating mantle or turn off its heating circuit.

[0028] Building upon systems capable of direct temperature measurement, achieving precise automatic control of the heating process becomes another challenge. In existing devices equipped only with temperature displays, even with real-time extraction temperature data, operators still need to continuously monitor the readings and manually adjust the heating mantle's power knob. This manual control method suffers from significant lag; operators cannot react instantly to rapid temperature fluctuations, and manual adjustment itself is difficult to quantify precisely, leading to frequent fluctuations in the extraction temperature around the target value, making it difficult to maintain stable experimental conditions.

[0029] To address this issue, this implementation plan integrates an automatic monitoring system based on direct temperature monitoring. This system comprises three core components. A signal receiving module continuously acquires real-time temperature signals from an immersion temperature sensor. These signals are transmitted to a data processing module, which internally presets a specific temperature threshold range that meets experimental requirements. The data processing module continuously compares and judges the received real-time temperature signals against the preset range. The comparison result is immediately sent to a control signal output module, which establishes an electrical connection with the power supply circuit of the heating mantle.

[0030] When the system detects that the real-time temperature is below the lower limit of the preset range, the control signal output module issues a command to increase the heating power of the heating mantle, or to activate its heating circuit if it is in the off state, thereby starting to heat the round-bottom flask. Conversely, when the real-time temperature is detected to be above the upper limit of the preset range, the control signal output module issues the opposite command, reducing the heating power of the heating mantle, or, if necessary, completely disconnecting its heating circuit to stop heating. In this way, the system forms a complete closed-loop control circuit, which can automatically and promptly adjust the heat input in reverse based on the actual temperature of the extract, thereby effectively stabilizing the temperature of the extract within the expected range, replacing the unstable control mode that relies on manual judgment and operation.

[0031] Furthermore, the monitoring system also includes a network communication module; the network communication module is connected to the data processing module and is used to send the real-time temperature signal, the temperature threshold range, and the working status data of the electric heating mantle to a remote terminal via a wireless network, and to receive control commands from the remote terminal; the control commands include commands to modify the temperature threshold range, commands to start the electric heating mantle, and commands to stop the electric heating mantle; the data processing module is also used to update the internal temperature threshold range according to the received control commands, or to send corresponding start / stop signals to the control signal output module.

[0032] Even after implementing automatic closed-loop control of the extraction solution temperature, operators still need to be near the equipment to observe the system status or adjust parameters. This local control mode restricts personnel freedom of movement for extraction processes that require long-term operation, and causes numerous inconveniences when managing multiple devices simultaneously or moving between different laboratories. Operators must be physically present to check if the temperature profile is normal or modify temperature settings according to the needs of each stage of the experiment. This working method is inefficient and cannot achieve centralized monitoring and recording of the process.

[0033] To overcome this limitation, this implementation plan integrates network communication capabilities into the existing automatic monitoring system. The system adds a network communication module that connects to the data processing module. Key information that was previously processed and displayed locally—including real-time temperature signals from temperature sensors, the current effective temperature threshold range, and the actual operating status of the heating mantle, such as heating power percentage or start / stop status—is continuously transmitted to a designated remote terminal, such as an internet-connected computer or mobile device, via the built-in wireless network unit. Simultaneously, the communication link is bidirectional, allowing the remote terminal to send control commands. These commands primarily cover modifications to the temperature threshold range, start commands for the heating mantle, and emergency stop commands.

[0034] When a remote user issues a new temperature threshold command on their terminal based on observed data changes or experimental plan adjustments, the command is transmitted back to the data processing module via the network. The data processing module parses the command and overwrites the previously preset value with the new threshold range, thus immediately changing the baseline for subsequent temperature control. Similarly, if a start / stop command is issued remotely, the data processing module directly forwards the corresponding signal to the control signal output module, enabling remote on / off control of the heating mantle power supply. This mechanism allows operators to fully grasp the system's operational status without being physically present at the experimental equipment, and to intervene as needed, greatly improving operational flexibility and the convenience of experimental management.

[0035] Furthermore, the data processing module also includes a communication status monitoring unit and a local security policy unit; the communication status monitoring unit continuously monitors the communication link status between the network communication module and the remote terminal; the local security policy unit has a preset security operation procedure, which is activated when the following two conditions are met simultaneously: first, the communication status monitoring unit detects that the duration of the communication interruption reaches a first preset time threshold; second, the real-time temperature signal received by the data processing module exceeds the upper limit of the temperature threshold range; when the security operation procedure is activated, the local security policy unit takes over the control of the control signal output module and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to zero within a time period of 30 seconds to 300 seconds.

[0036] In systems relying on remote monitoring and control, the reliability of network communication becomes a new concern. If the remote link is interrupted due to network fluctuations or failures, the local control system may no longer be able to receive instructions from the remote terminal, and the system will continue to operate according to the last settings. If the temperature of the extraction solution rises and exceeds the safe range at this time, the remote user will neither be able to perceive this anomaly nor intervene remotely, posing a risk of continued temperature increases. However, if the system immediately initiates a protective shutdown upon detecting any brief communication interruption, frequent network jitter may repeatedly interrupt the normal, long-term extraction process, affecting experimental efficiency.

[0037] To resolve this contradiction, this implementation plan enhances local decision-making and security logic within the data processing module. The module contains a communication status monitoring unit and a local security policy unit. The communication status monitoring unit continuously probes the connection status between the network communication module and the remote terminal, identifying whether the communication link is active or interrupted, and recording the duration of the interruption. The local security policy unit pre-stores a security operation procedure. This procedure is not triggered by a single condition but rather by a composite judgment logic. It requires two key conditions to be met simultaneously: First, the communication status monitoring unit confirms that the communication interruption with the remote terminal has lasted for a pre-set time threshold, long enough to exclude most short-term network fluctuations; second, the real-time temperature signal currently received by the data processing module has indeed exceeded the upper limit of the preset temperature threshold range.

[0038] Only when both conditions—"confirmed loss of contact" and "confirmed overheating"—are met simultaneously is the system deemed to have entered a potential risk state of remote uncontrollability and local overheating. At this point, the local safety policy unit is activated and immediately takes over control of the control signal output module. Instead of commanding a sudden power outage, it issues a gradual power reduction command to the control signal output module, causing the heating power of the heating mantle to smoothly and linearly decrease from its current value to zero over a set period of time. This gradual cooling method avoids the potential adverse effects on equipment or samples caused by sudden temperature changes. Through this design, the system can minimize unnecessary interference with normal experimental processes while ensuring safety, only initiating the local safety intervention procedure when communication is truly interrupted for an extended period and an overheating risk actually occurs.

[0039] Furthermore, the data processing module also includes a sensor diagnostic unit; the sensor diagnostic unit is connected to the signal receiving module and is used to perform periodic or continuous diagnostics on the temperature sensor; the diagnostics include monitoring the impedance value of the temperature sensor signal transmission line loop and comparing the impedance value with a preset normal impedance range; when the impedance value continuously exceeds the normal impedance range to a second preset time threshold, the sensor diagnostic unit determines that the temperature sensor has an open circuit or short circuit fault and generates a sensor fault signal; the local safety policy unit also has a preset sensor fault response program; when the sensor diagnostic unit generates the sensor fault signal, the sensor fault response program is activated, the local safety policy unit then takes over control and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to a preset safe heat preservation power value or zero within 10 to 60 seconds.

[0040] In automated control systems, temperature sensors serve as a critical data source, and their operational status is paramount. If a sensor experiences an internal fault, such as an open circuit or short circuit, the control system will receive a constant, significantly inaccurate, or completely invalid electrical signal. Based on this erroneous signal, the system may make decisions completely contrary to reality. For example, it might continue heating when the actual temperature is too high due to a consistently low-temperature signal, or incorrectly stop heating when the temperature is normal due to an abnormally high signal. Both scenarios could lead to experimental failure or even safety risks. Conventional systems often lack mechanisms for monitoring the sensor's health status.

[0041] To address this potential risk, this implementation plan incorporates a sensor diagnostic unit within the data processing module. This unit, connected to the signal receiving module, performs periodic or continuous measurements of the electrical impedance of the temperature sensor signal transmission line loop. It compares the measured real-time impedance value with a preset normal operating impedance range. This normal range is pre-calibrated based on the typical impedance characteristics of a healthy temperature sensor and its connecting lines. Considering potential transient interference during measurement, the diagnostic logic does not immediately trigger an alarm when the impedance exceeds the range; instead, it requires the abnormal impedance state to persist for a preset time threshold. This continuous assessment helps filter out transient electrical noise or occasional interference, improving diagnostic accuracy.

[0042] Upon confirming a persistent open-circuit or short-circuit fault in the sensor, the sensor diagnostic unit generates a clear sensor fault signal. This signal is immediately sent to the local safety strategy unit. The local safety strategy unit has a pre-set sensor fault response procedure specifically designed to handle such situations. Upon receiving the fault signal, this procedure is immediately activated, and the local safety strategy unit takes over system control. It instructs the control signal output module to linearly reduce the heating power of the heating mantle to a preset safe insulation power value or directly reduce it to zero within a relatively short and set time. This safe insulation power is typically extremely low, such as the power used to prevent condensation in special circumstances, or it can directly shut down heating to ensure absolute safety. Through this proactive diagnostic and safety takeover mechanism, the system can take timely and predetermined measures when a problem occurs in the critical link of signal source failure, guiding the system to a controllable and safe state, effectively avoiding uncontrolled heating due to erroneous data.

[0043] Furthermore, the extraction system also includes a local audible and visual alarm, which is electrically connected to the data processing module. After generating the sensor fault signal, the sensor diagnostic unit simultaneously sends the signal to the local security strategy unit and the local audible and visual alarm. Upon receiving the sensor fault signal, the local audible and visual alarm is triggered and emits a continuous audible and visual warning signal. The audible and visual warning signal remains active during the duration of the sensor fault signal. The audible and visual warning signal is automatically deactivated after the sensor diagnostic unit detects that the impedance value has returned to the normal impedance range and remains within a third preset time threshold.

[0044] Even in systems equipped with sensor fault diagnosis and automatic protection functions, there remains an easily overlooked aspect. When a temperature sensor malfunctions and triggers a safety procedure, the system can automatically reduce the heating power to a safe level. However, this critical change in state may only be reflected on the monitoring interface through data changes. If operators are not closely monitoring the screen, or if remote communication is also disrupted, on-site personnel may not immediately realize that the system has entered fault protection mode. This situation can persist, potentially leading to untimely fault handling, delays in experiments, and, in extreme cases, improper operation by unsuspecting on-site personnel, potentially introducing new risks.

[0045] To address this shortcoming in human-computer interaction, this implementation plan adds a local audible and visual alarm to the system and electrically connects it to the data processing module. When the sensor diagnostic unit confirms a fault and generates a sensor fault signal, this signal is sent in parallel to two destinations: one is the local safety policy unit responsible for performing safety operations, as mentioned earlier, and the other is this newly added local audible and visual alarm. The alarm is triggered the instant it receives the fault signal, immediately emitting a clear and easily identifiable audible and visual warning signal. This warning combines a high-frequency buzzer sound with flashing lights, aiming to create a physical environmental prompt that cannot be easily ignored by on-site personnel.

[0046] This audible and visual warning signal is not a brief reminder; it remains active throughout the entire duration of the sensor fault signal. As long as the fault is not resolved, the alarm persists, continuously alerting personnel. Fault resolution, i.e., the sensor circuit impedance returning to the normal range, also requires a brief stabilization confirmation period to prevent false alarms caused by intermittent contact. The fault signal will only be deactivated once the sensor diagnostic unit continuously monitors and confirms that the impedance value has stabilized within the normal range and exceeded the third preset time threshold. With the deactivation of the fault signal, the audible and visual alarm also stops sounding. This local audible and visual alarm mechanism effectively compensates for the shortcomings of purely automated systems in terms of state perception, ensuring that any critical fault state can be quickly and accurately detected by on-site personnel, providing timely information support for subsequent troubleshooting and handling.

[0047] Furthermore, the data processing module is also connected to a non-volatile memory, which pre-stores a solvent boiling point database. The solvent boiling point database contains identification information of various common solvents and their corresponding standard boiling point data. The data processing module is configured to: receive the identification information of a target solvent specified by the user through an input device; query the solvent boiling point database based on the identification information to obtain the corresponding standard boiling point data; and automatically calculate and set the temperature threshold range based on the standard boiling point data. The upper limit of the temperature threshold range is set to a value 5°C to 15°C lower than the standard boiling point data, and the lower limit of the temperature threshold range is set to a value 15°C to 30°C lower than the standard boiling point data.

[0048] In systems that rely on operators manually setting temperature thresholds, the appropriateness of these thresholds largely depends on individual experience. Different operators may set significantly different heating temperature ranges for the same solvent, lacking a unified, scientific benchmark. This subjectivity can lead to overly conservative temperature settings, resulting in slow extraction rates, or temperatures set too close to the solvent's boiling point, increasing the risk of bumping or excessive solvent evaporation. Especially when dealing with unfamiliar solvents, operators may set inappropriate parameters due to the inability to quickly ascertain the precise boiling point, affecting the reliability and safety of the experiment.

[0049] To address this issue, this implementation plan connects a non-volatile memory to the data processing module, which pre-stores a database containing identification information for various common solvents and their corresponding standard boiling point data. When an extraction experiment is required, the user does not need to manually calculate the temperature threshold from memory or by consulting a manual. Instead, they can select from the solvent list or directly input the identification information of the target solvent, such as the solvent name or abbreviation, through the system's input device, such as a touchscreen or a connected external keyboard.

[0050] Upon receiving the solvent identifier information specified by the user, the data processing module immediately queries its internal solvent boiling point database to quickly retrieve the corresponding standard boiling point data. Then, based on a preset algorithm, the module automatically calculates and intelligently sets an appropriate temperature threshold range using this standard boiling point data as a benchmark. Specifically, the system sets the upper limit of the temperature threshold range to a value below the solvent's standard boiling point by a certain degree Celsius, while the lower limit is set to a value further below the standard boiling point. These two offsets are preset within the system to ensure that the extraction process takes place within a safe range where the solvent maintains good activity while avoiding violent boiling. In this way, the temperature threshold setting process is automated and standardized, significantly reducing reliance on the operator's personal experience. This allows for consistent and reliable control parameters based on the objective physical properties of the solvent in each experiment, thereby improving the repeatability and safety of experimental results.

[0051] Furthermore, the monitoring system also includes a liquid level status judgment module, which is configured to: continuously record real-time temperature data measured by the temperature sensor and calculate its rate of change over time; and compare the real-time temperature data with a preset warning temperature value T. alert In comparison, the warning temperature value is 10°C to 20°C lower than the boiling point of the solvent used in the extraction; when the real-time temperature data reaches or exceeds the warning temperature value T within a continuous first time period Δt1. alert Furthermore, the calculated rate of temperature change within this Δt1 segment is lower than the preset positive rate of change threshold α. max When the extract level is too low or the solvent is close to being evaporated, it is determined that the extract level is too low or the solvent is close to being evaporated; wherein, Δt1 is 30 seconds to 120 seconds, and α max The speed is 0.1℃ / second to 0.5℃ / second; when it is determined that the liquid level of the extract is too low or the solvent is close to being evaporated, a control command is generated and sent to the control circuit of the heating mantle to reduce the heating power of the heating mantle to a preset safe power value or cut off its heating power supply. The safe power value is 0% to 10% of the rated power.

[0052] After achieving precise temperature control and sensor self-diagnosis, the system still needs to address a common problem during long-term extraction. As the solvent evaporates, the liquid level in the round-bottom flask gradually drops. If an anomaly occurs, such as a malfunction in the condensation system, excessive heating temperature, or insufficient initial solvent addition, causing the liquid level to fall below the temperature sensor's sensing element, the probe will be exposed to solvent vapor instead of liquid. The temperature characteristics of vapor and liquid differ, potentially leading to an abnormally high and slowed temperature reading. If the control system continues heating based on this inaccurate signal, it will be unable to perceive the true state of the remaining liquid, posing a risk of overheating the residue at the bottom of the flask.

[0053] To address this situation, this implementation plan introduces a liquid level status judgment module into the monitoring system. The core logic of this module is not to directly measure the liquid level, but rather to indirectly infer the liquid level status by analyzing the behavioral characteristics of temperature readings. It continuously records real-time temperature data measured by an immersion temperature sensor and calculates its rate of change over time. The system presets a key warning temperature value, set at a level that is a reasonable margin below the boiling point of the solvent used. The module's workflow is as follows: when it detects that the real-time temperature data reaches or exceeds the warning temperature value for a specific period of time, and simultaneously calculates that the rate of temperature change during this period is significantly lower than the rapid rise characteristic that should occur during normal boiling of the liquid, it triggers a logical judgment.

[0054] This combination of high temperature but slow heating is consistent with the physical phenomenon of a sensor exposed to superheated steam while the liquid below is insufficient to maintain good thermal convection. Based on this, the module determines that the system may be in a state where the extractant level is too low or the solvent is nearing evaporation. Once this determination is made, the liquid level assessment module immediately generates a high-priority control command and sends it directly to the heating mantle's control loop. This command requires the heating power of the heating mantle to be rapidly reduced to a preset, extremely low safe power value, or its heating power to be completely cut off, thereby proactively preventing potential overheating accidents and providing a buffer time for operator intervention.

[0055] Furthermore, the liquid level state judgment module is also configured to initiate a re-judgment program after performing the operation of reducing heating power or cutting off power. The re-judgment program includes: maintaining the low power or power-off state for a fourth preset time Δt4, and then controlling the electric heating mantle to restore the initial heating power; Δt4 is 60 seconds to 300 seconds, and the initial heating power is 10% to 30% of the rated power; continuously monitoring the real-time temperature data and rate of change during the second time period Δt2 after the heating is restored, Δt2 is 60 seconds to 180 seconds; if the temperature data monitored during the Δt2 stage is always lower than the low temperature threshold T of the solvent boiling point... low If the absolute value of the average temperature change rate within Δt2 is less than β, then the extract has been confirmed to have evaporated to dryness; where T low The temperature must be at least 30°C below the solvent boiling point, with β at 0.05°C / second; if the monitored temperature rises within Δt2 and again exceeds the warning temperature value T, the warning temperature will be maintained. alert If the result is incorrect, it is determined to be a misjudgment or a brief boiling over, and the heating mantle is immediately controlled to resume the normal extraction heating process.

[0056] After initially determining the liquid level is too low based on temperature characteristics and implementing protective cooling, the system may face a new problem. A single judgment can be affected by accidental factors, such as a brief, violent boiling of the solvent, causing a sudden temperature rise and a temporary decrease in the heating rate due to the large number of bubbles hindering heat transfer, simulating a low liquid level characteristic. If the system maintains a low-power or shutdown state for an extended period based solely on this single judgment, it may unnecessarily interrupt an extraction process that is actually still in progress, affecting experimental efficiency.

[0057] To address this potential for misjudgment, this implementation scheme adds a re-judgment procedure to the liquid level assessment module. This procedure automatically activates after the system first performs a reduction in heating power or a power cut-off operation. The process is as follows: The system first maintains the low power or power-off state for a preset period of time, allowing the round-bottom flask and its contents, especially bubbles that may have been generated due to brief boiling, to calm and stabilize. Subsequently, the system controls the heating mantle to restore a lower initial heating power, significantly lower than the normal extraction power, intended to provide a trial of gentle heating.

[0058] After resuming heating, the system continuously and closely monitors real-time temperature data and its trends for another preset period. Two typical scenarios may occur. First, the monitored temperature data remains consistently below a low-temperature threshold well below the solvent's boiling point, and the average temperature change during this period is extremely weak, indicating a lack of heating capacity. This aligns with the characteristic that the solvent in the round-bottom flask has essentially evaporated, leaving insufficient liquid for heating, thus confirming the previous assessment of "evaporation." Second, the temperature data shows a significant upward trend during the monitoring period and quickly reaches or exceeds the previously set warning temperature. This indicates that there is still sufficient solvent in the flask to respond normally to heating, and the initial assessment was likely due to a brief, abnormal disturbance such as a sudden boiling. In this case, the system will determine this as a misjudgment and immediately control the heating mantle to exit its protective state, resuming the heating process required for normal extraction. This reassessment mechanism, by introducing a verification step, significantly improves the reliability of the system's status assessment and effectively avoids unnecessary experimental interruptions caused by occasional anomalies.

[0059] Furthermore, the remote terminal is a mobile terminal; the extraction system also includes a camera, which is positioned to capture images of the round-bottom flask and extraction tube, and is connected to the network communication module of the monitoring system; the network communication module also sends the video data collected by the camera to the mobile terminal; the mobile terminal has a monitoring application installed, which provides a user interface for real-time display of received data and video data; the user interface also includes input controls for receiving user control commands, including temperature setting commands and electric heating mantle start / stop commands; the monitoring application sends the received control commands to the data processing module through the network communication module; the data processing module updates the temperature threshold range according to the temperature setting command, or sends a corresponding control signal to the control signal output module according to the electric heating mantle start / stop command.

[0060] While remote data monitoring and command control have been implemented, operators can acquire data such as temperature and status, but lack direct visual perception of the experimental site. For example, relying solely on temperature data curves makes it difficult to accurately distinguish between normal boiling and abnormal bumping, to observe whether solvent reflux in the extraction tube is smooth, or to confirm the remaining amount and color change of solvent in the round-bottom flask. This kind of remote judgment, which relies purely on data, is inherently uncertain, limiting the accuracy and timeliness of remote intervention. Operators may make conservative or inappropriate decisions due to incomplete information.

[0061] This implementation scheme also integrates a camera into the system hardware. This camera is strategically positioned to clearly capture the main body of the round-bottom flask and key areas of the extraction tube, thus covering the core visual scene of the extraction process. The camera is connected to the network communication module of the monitoring system, enabling its real-time video data, along with temperature, status, and other data streams, to be synchronously transmitted via wireless network to remote mobile terminals, such as smartphones or tablets.

[0062] On the mobile terminal side, a specially designed monitoring application provides a comprehensive user interface. This interface not only dynamically updates various data from the system in numerical and graphical form, but also includes a video display area for real-time playback of the scene. This allows remote users to simultaneously obtain information from both "data" and "scene" dimensions, achieving more comprehensive process monitoring. Furthermore, the user interface includes input controls for receiving user control commands, such as a temperature setting slider and virtual start / stop buttons for the heating mantle. When the user adjusts the temperature setting or clicks the start / stop button on the interface, these commands are captured by the monitoring application and transmitted back to the local data processing module via the network communication module. The data processing module parses these commands, updates its internal temperature threshold range accordingly, or directly sends signals to the control signal output module to control the on / off state of the heating mantle. By introducing a visual channel and improving interactive functions, the system constructs a more information-rich remote monitoring and control environment, enabling users to manage and intervene in remote experiments more confidently and accurately based on a WYSIWYG approach.

[0063] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An extraction system capable of real-time monitoring of the temperature of the extractant, comprising an extraction tube, a condenser, a heating mantle, a round-bottom flask, and a monitoring system, wherein one end of the extraction tube is connected to the condenser, and the other end of the extraction tube is connected to the round-bottom flask, and the heating mantle is fitted over the lower part of the round-bottom flask for heating the round-bottom flask, characterized in that, The round-bottom flask is a multi-necked round-bottom flask with at least two necks. The first neck of the multi-necked round-bottom flask is connected to the extraction tube via a ground joint. The second neck of the multi-necked round-bottom flask has a standard ground joint interface, and a temperature sensor is installed on the second neck via the standard ground joint interface. The temperature sensor includes a sensing part and a signal transmission line. The upper end of the sensing part is sealed and fixed to the standard ground joint interface via a ground joint adapter. The lower end of the sensing part extends into the internal space of the round-bottom flask, and its end is located 10 mm to 100 mm above the bottom of the round-bottom flask. The signal transmission line is led out from the sensing part for connecting to a monitoring system.

2. The extraction system capable of real-time monitoring of the extractant temperature according to claim 1, characterized in that, The monitoring system includes a signal receiving module, a data processing module, and a control signal output module. The signal receiving module is connected to the signal transmission line of the temperature sensor and is used to receive temperature signals. The data processing module has a preset temperature threshold range and compares the real-time temperature signal received by the signal receiving module with the temperature threshold range. The control signal output module is connected to the power circuit of the heating mantle. When the real-time temperature signal is lower than the lower limit of the temperature threshold range, the control signal output module outputs a signal to increase the heating power of the heating mantle or turn on its heating circuit. When the real-time temperature signal is higher than the upper limit of the temperature threshold range, the control signal output module outputs a signal to decrease the heating power of the heating mantle or turn off its heating circuit.

3. The extraction system capable of real-time monitoring of the extractant temperature according to claim 2, characterized in that, The monitoring system further includes a network communication module; the network communication module is connected to the data processing module and is used to send the real-time temperature signal, the temperature threshold range, and the working status data of the electric heating mantle to a remote terminal via a wireless network, and to receive control commands from the remote terminal; the control commands include commands to modify the temperature threshold range, commands to start the electric heating mantle, and commands to stop the electric heating mantle; the data processing module is also used to update the internal temperature threshold range according to the received control commands, or to send corresponding start / stop signals to the control signal output module.

4. The extraction system capable of real-time monitoring of the extractant temperature according to claim 3, characterized in that, The data processing module further includes a communication status monitoring unit and a local security policy unit; the communication status monitoring unit continuously monitors the communication link status between the network communication module and the remote terminal; the local security policy unit has a preset security operation procedure, which is activated when the following two conditions are met simultaneously: first, the communication status monitoring unit detects that the duration of the communication interruption reaches a first preset time threshold. Second, the real-time temperature signal received by the data processing module exceeds the upper limit of the temperature threshold range; When the safety operation procedure is activated, the local safety policy unit takes over control of the control signal output module and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to zero within a time period of 30 to 300 seconds.

5. The extraction system capable of real-time monitoring of the extract temperature according to claim 4, characterized in that, The data processing module further includes a sensor diagnostic unit; the sensor diagnostic unit is connected to the signal receiving module and is used to perform periodic or continuous diagnostics on the temperature sensor; the diagnostics include monitoring the impedance value of the temperature sensor signal transmission line loop and comparing the impedance value with a preset normal impedance range; when the impedance value continuously exceeds the normal impedance range to a second preset time threshold, the sensor diagnostic unit determines that the temperature sensor has an open circuit or short circuit fault and generates a sensor fault signal; the local safety policy unit also has a preset sensor fault response program; when the sensor diagnostic unit generates the sensor fault signal, the sensor fault response program is activated, the local safety policy unit then takes over control and instructs the control signal output module to linearly reduce the heating power of the electric heating mantle to a preset safe heat preservation power value or zero within 10 to 60 seconds.

6. The extraction system capable of real-time monitoring of the extract temperature according to claim 5, characterized in that, The extraction system also includes a local audible and visual alarm, which is electrically connected to the data processing module. After generating the sensor fault signal, the sensor diagnostic unit sends the signal to both the local security strategy unit and the local audible and visual alarm. Upon receiving the sensor fault signal, the local audible and visual alarm is triggered and emits a continuous audible and visual warning signal. The audible and visual warning signal remains active during the duration of the sensor fault signal. The audible and visual warning signal is automatically deactivated after the sensor diagnostic unit detects that the impedance value has returned to the normal impedance range and remains within a third preset time threshold.

7. The extraction system capable of real-time monitoring of the extract temperature according to claim 2, characterized in that, The data processing module is also connected to a non-volatile memory, which pre-stores a solvent boiling point database. The solvent boiling point database contains identification information of various common solvents and their corresponding standard boiling point data. The data processing module is configured to: receive the identification information of a target solvent specified by the user through an input device; query the solvent boiling point database based on the identification information to obtain the corresponding standard boiling point data; and automatically calculate and set the temperature threshold range based on the standard boiling point data. The upper limit of the temperature threshold range is set to be 5°C to 15°C lower than the standard boiling point data, and the lower limit of the temperature threshold range is set to be 15°C to 30°C lower than the standard boiling point data.

8. The extraction system capable of real-time monitoring of the extract temperature according to claim 1, characterized in that, The monitoring system also includes a liquid level status judgment module, which is configured to: continuously record real-time temperature data measured by the temperature sensor and calculate its rate of change over time; and compare the real-time temperature data with a preset warning temperature value T. alert In comparison, the warning temperature value is 10°C to 20°C lower than the boiling point of the solvent used in the extraction; when the real-time temperature data reaches or exceeds the warning temperature value T within a continuous first time period Δt1. alert Furthermore, the calculated rate of temperature change within this Δt1 segment is lower than the preset positive rate of change threshold α. max When the extract level is too low or the solvent is close to being evaporated, it is determined that the extract level is too low or the solvent is close to being evaporated; wherein, Δt1 is 30 seconds to 120 seconds, and α max The speed is 0.1℃ / second to 0.5℃ / second; when it is determined that the liquid level of the extract is too low or the solvent is close to being evaporated, a control command is generated and sent to the control circuit of the heating mantle to reduce the heating power of the heating mantle to a preset safe power value or cut off its heating power supply. The safe power value is 0% to 10% of the rated power.

9. The extraction system capable of real-time monitoring of the extract temperature according to claim 8, characterized in that, The liquid level state judgment module is further configured to initiate a re-judgment program after performing the operation of reducing heating power or cutting off power. The re-judgment program includes: maintaining the low power or power-off state for a fourth preset time Δt4, and then controlling the electric heating mantle to restore the initial heating power; Δt4 is 60 seconds to 300 seconds, and the initial heating power is 10% to 30% of the rated power; continuously monitoring the real-time temperature data and rate of change during the second time period Δt2 after the heating is restored, Δt2 is 60 seconds to 180 seconds; if the temperature data monitored during the Δt2 stage is always lower than the low temperature threshold T of the solvent boiling point... low If the absolute value of the average temperature change rate within Δt2 is less than β, then the extract has been confirmed to have evaporated to dryness; where T low The temperature must be at least 30°C below the solvent boiling point, with β at 0.05°C / second; if the monitored temperature rises within Δt2 and again exceeds the warning temperature value T, the warning temperature will be maintained. alert If the result is incorrect, it is determined to be a misjudgment or a brief boiling over, and the heating mantle is immediately controlled to resume the normal extraction heating process.

10. The extraction system capable of real-time monitoring of the extract temperature according to claim 3, characterized in that, The remote terminal is a mobile terminal; the extraction system also includes a camera, which is positioned to capture images of the round-bottom flask and extraction tube, and is connected to the network communication module of the monitoring system; the network communication module also sends the video data collected by the camera to the mobile terminal; the mobile terminal has a monitoring application installed, which provides a user interface for real-time display of received data and video data; the user interface also includes input controls for receiving user control commands, including temperature setting commands and heating mantle start / stop commands; the monitoring application sends the received control commands to the data processing module through the network communication module; the data processing module updates the temperature threshold range according to the temperature setting command, or sends a corresponding control signal to the control signal output module according to the heating mantle start / stop command.

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