An isolated explosion-proof thermal oil furnace

Abstract

This invention relates to the field of thermal oil furnace technology, specifically an isolated explosion-proof thermal oil furnace, comprising a frame, furnace body assembly, heating element, thermal oil circulation pump, and control cabinet. The furnace body assembly includes an inner furnace body and an outer furnace body, forming a sealed isolation chamber. A porous ceramic filter layer is installed within the isolation chamber. The heating end of the heating element is threaded into the inner furnace body. An inert gas interface is provided on the outer furnace body. The control cabinet contains a monitoring module, including a temperature sensor, a pressure sensor, and a thermal oil leakage sensor. Each sensor and the heating element are electrically connected to the control module. This invention, through the dual physical barrier formed by the inner and outer furnace bodies, combined with the adsorption and blocking effect of the porous ceramic filter layer, constructs an inherently safe isolation between the thermal oil system and the external environment. Real-time monitoring by multiple sensors enables rapid emergency response, thus improving the explosion-proof safety of the thermal oil furnace.

Description

Technical Field

[0001] This invention relates to the field of thermal oil furnace technology, specifically to an isolated explosion-proof thermal oil furnace. Background Technology

[0002] As a core heating device in flammable and explosive environments, the reliability of the physical isolation structure of explosion-proof thermal oil heaters directly determines their explosion-proof safety. It is also crucial to prevent thermal oil leakage and the release of volatile components, thereby preventing explosions. Currently, the physical isolation structures of existing explosion-proof thermal oil heaters in the industry have many problems. Some are overly complex in design with numerous components, leading to high manufacturing costs and maintenance difficulties; others are too simple in structure, resulting in poor isolation and failing to effectively isolate the thermal oil circulation system from the external flammable and explosive environment, easily leading to potential hazards such as thermal oil leakage and oxidation.

[0003] Existing explosion-proof thermal oil boilers mostly rely on emergency circulation during power outages and external cooling of pipelines. Chinese utility model patent with publication number CN217503984U proposes a thermal oil boiler device with explosion-proof function. It uses a diesel generator to drive a circulation pump to avoid hot oil retention and wraps a cooling pipe around the thermal oil pipe to achieve cooling. However, it still has the problems of delayed passive protection response and limited cooling efficiency, which makes it difficult to meet the usage requirements of high-safety-level flammable and explosive scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide an isolated explosion-proof thermal oil heater to solve the problems of delayed passive protection response and limited cooling efficiency in existing isolated explosion-proof thermal oil heaters.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An explosion-proof, isolated thermal oil heater includes a frame, a furnace body assembly, a heating element, a thermal oil circulation pump, and a control cabinet. The furnace body assembly is horizontally mounted on the frame and includes an inner furnace body and an outer furnace body, forming a sealed isolation chamber. A porous ceramic filter layer is provided within the isolation chamber. The heating element has a heating end and a wiring terminal. The heating end is threaded into the inner furnace body, and an isolated junction box is installed on the wiring terminal. An inlet and an outlet are respectively provided on the bottom and right end face of the inner furnace body. The thermal oil circulation pump and the control cabinet are both mounted on the frame. The inlet is connected to the heat transfer oil circulation pump via a pipe. An inert gas interface is provided on the outer furnace body, located on the side wall of the outer furnace body and connected to the isolation chamber. The control cabinet contains a monitoring module and a control module. The monitoring module includes a temperature sensor, a pressure sensor, and a heat transfer oil leakage sensor. The heating element, temperature sensor, pressure sensor, and heat transfer oil leakage sensor are all electrically connected to the control module. This invention achieves significant technical effects through the organic combination of the above structures: by integrating the furnace body components, circulation pump, and control cabinet onto the same frame, a skid-mounted structure is formed. Significantly simplifies on-site installation and improves transportation stability; employs a dual-cavity structure consisting of an inner and outer furnace body, forming a sealed isolation chamber between them, creating a double physical barrier between the heat transfer oil system and the external environment, achieving intrinsically safe isolation; the porous ceramic filter layer installed in the isolation chamber not only prevents the formation of a sealed dead space that could lead to the accumulation of flammable and explosive gases, but also enhances the ability to detect minute leaks through its microporous adsorption and retention effects, providing more response time for leak detection; the heating element's heating end is threadedly connected to the inner furnace body, and with the isolation junction box at the wiring terminal, it strengthens high-temperature sealing reliability while ensuring... Electrical sparks are completely isolated from potential leakage areas, eliminating the risk of explosion. The liquid inlet is located at the bottom, and the liquid outlet at the top of the end face, with the circulation pump positioned on the inlet side, forming a "bottom-in, top-out" flow path that effectively avoids high-temperature cavitation and improves heating uniformity. The inert gas interface connects to the isolation chamber, maintaining an inert atmosphere and regulating pressure within the chamber, eliminating explosion conditions at their source and protecting the sealing structure. The integrated monitoring module in the control cabinet uses temperature, pressure, and leakage sensors for coordinated monitoring. All signals are processed uniformly by the control module, achieving millisecond-level emergency response and significantly reducing false alarm and missed alarm rates. In summary, this invention, while ensuring efficient heating, significantly improves the safety, reliability, and integration of the equipment in flammable and explosive environments, demonstrating outstanding substantive features and significant progress.

[0007] Preferably, a flow control valve is provided at the inert gas interface, and an inert gas concentration sensor is provided in the isolation chamber. Both the flow control valve and the inert gas concentration sensor are electrically connected to the control module. A guide plate is provided between the inert gas interface and the porous ceramic filter layer. The guide plate is fixed to the outside of the inner furnace body and is fitted to the porous ceramic filter layer. Guide holes are evenly distributed on the surface of the guide plate, arranged in a matrix along the length of the guide plate. The hole diameter gradually decreases from the side closer to the inert gas interface to the side farther away from the interface, forming a gradient airflow distribution structure. When the inert gas enters through the interface, it first impacts the guide plate and is dispersed into multiple fine airflows through the guide holes of different diameters, uniformly penetrating to all areas of the porous ceramic filter layer, avoiding excessively high or low local inert gas concentrations. Meanwhile, an inert gas concentration sensor monitors the gas composition within the isolation chamber in real time. When the concentration falls below a set threshold, the control module immediately drives the flow control valve to increase its opening to replenish inert gas. When the concentration exceeds the threshold, the valve opening decreases, ensuring that the chamber is always maintained within the optimal inert atmosphere range. This guarantees both explosion-proof performance and prevents waste of inert gas. The baffle plate also effectively buffers the direct impact of airflow on the porous ceramic filter layer, preventing structural loosening or pore blockage caused by airflow erosion after long-term use, thus extending its service life.

[0008] Preferably, a safety vent pipe is installed on the outer furnace body. One end of the safety vent pipe is connected to the isolation chamber, and the other end extends to a safe outdoor area. The safety vent pipe is equipped with a dual-control valve, which is electrically connected to the control module. When the pressure in the isolation chamber abnormally increases or the inert gas concentration deviates significantly from the safe range due to unforeseen circumstances, the control module will quickly activate the dual-control valve to promptly discharge the abnormal gas in the chamber to the safe outdoor area through the safety vent pipe, preventing the accumulation of dangerous gas indoors. A manual valve serves as an emergency backup. In case of a malfunction in the automatic control system or during equipment maintenance, the operator can manually open the valve to ensure safe depressurization of the isolation chamber. The outlet end of the safety vent pipe is also equipped with a rain cap and a fireproof net, which prevents rainwater backflow and effectively blocks external fire sources from entering the pipe, further improving the reliability of the entire safety vent system.

[0009] Preferably, the temperature sensor is coaxially embedded within the heating end, and a high-temperature resistant protective sleeve is fitted over the outside of the temperature sensor. The pressure sensor is located within the isolation chamber, near the safety vent pipe interface. The high-temperature resistant protective sleeve is made of 310S stainless steel with a wall thickness of not less than 3mm, capable of withstanding the high-temperature environment and thermal shock during operation of the heating end, effectively protecting the internal temperature sensor from direct erosion by heat-conducting oil and high-temperature corrosion. Thermally conductive silicone grease is filled between the temperature sensor's measuring probe and the inner wall of the protective sleeve to ensure rapid and uniform heat transfer, improving the response speed and accuracy of temperature measurement. Its measurement range covers -50℃ to 500℃, with an accuracy level of ±0.5℃. The pressure sensor uses a diffused silicon pressure transmitter with a measurement range of 0-2.5MPa, capable of real-time monitoring of pressure changes within the isolation chamber. Its signal output uses a 4-20mA standard current signal for easy data interaction with the control module. To ensure measurement accuracy, the pressure sensor undergoes rigorous calibration before installation. Calibration points include zero, 25%, 50%, 75% of full scale, and full scale, with errors at each calibration point controlled within allowable limits. Simultaneously, the pressure sensor is installed close to the safety vent pipe interface, enabling it to detect abnormal pressure fluctuations within the isolation chamber immediately. This provides timely and reliable pressure data support for the control module to activate the dual-control valve of the safety vent pipe, further ensuring the safe and stable operation of the entire thermal oil heater system.

[0010] Preferably, the heat transfer oil leakage sensor is located at the bottom of the isolation chamber, directly below the inner furnace body. A collection tank is also provided at the bottom of the isolation chamber, corresponding to the heat transfer oil leakage sensor. A drain valve is located at the bottom of the collection tank, extending through the outer furnace body to the outside. When a heat transfer oil leak occurs in the inner furnace body, the leaked oil drips downwards due to gravity. The collection tank effectively collects the dripping oil, preventing it from spreading randomly at the bottom of the isolation chamber. This ensures that the leaked oil accurately collects in the sensing area of ​​the heat transfer oil leakage sensor, improving the sensor's sensitivity and reliability. The drain valve facilitates the timely discharge of the collected oil from the isolation chamber when a leak is detected or during equipment maintenance, preventing long-term accumulation of oil that could corrode the equipment or cause other safety hazards. Meanwhile, the design of the drain valve extending through the outer furnace body to the outside allows operators to conveniently control and operate the draining process from outside the furnace body without opening the isolation chamber, simplifying the operation process and ensuring operational safety.

[0011] Preferably, a waste heat recovery heat exchanger is provided at the liquid outlet. The waste heat recovery heat exchanger includes an outer jacket and an inner heat exchange tube. The inner heat exchange tube is connected to the liquid outlet, and the outer jacket is fitted over the inner heat exchange tube. The outer jacket has a cold medium inlet and a preheating medium outlet at its two ends, respectively. An annular preheating cavity is formed between the outer jacket and the inner heat exchange tube. A spiral guide vane is provided inside the annular preheating cavity. This spiral guide vane is spirally wound along the outer wall of the inner heat exchange tube, which can significantly extend the flow path of the cold medium in the annular preheating cavity, ensuring sufficient heat exchange time between the cold medium and the high-temperature heat transfer oil in the inner heat exchange tube, thereby improving waste heat recovery efficiency. When the high-temperature heat transfer oil flows out of the liquid outlet and enters the inner heat exchange tube, the large amount of waste heat it carries is transferred to the cold medium in the annular preheating cavity through the inner heat exchange tube wall. After entering through the cold medium inlet, the medium flows slowly along a spiral path under the guidance of the spiral guide vanes, exchanging heat thoroughly with the outer wall of the inner heat exchange tubes. After absorbing heat and increasing in temperature, it is finally discharged from the preheated medium outlet and can be used as boiler feedwater or other media requiring preheating. This achieves cascaded energy utilization and effectively reduces the overall system's energy consumption. Simultaneously, the spiral guide vanes also enhance the structural strength of the inner heat exchange tubes, reducing vibration and deformation under high-temperature and high-pressure conditions, and extending the service life of the heat exchanger.

[0012] Preferably, the threaded connection between the heating element's heating end and the inner furnace body is provided with a double sealing structure. The double sealing structure includes a threaded sealing groove and an end face sealing gasket. The threaded sealing groove is opened at the root of the thread on the heating end, and a PTFE sealing strip is embedded in the threaded sealing groove. The end face sealing gasket is made of high-temperature resistant fluororubber. The end face sealing gasket is sandwiched between the flange end face of the heating end and the inner wall of the inner furnace body. Through the tight fit between the PTFE sealing strip in the threaded sealing groove and the thread of the heating end, a first sealing barrier can be formed radially, effectively preventing heat transfer oil from leaking along the thread gap. The high-temperature resistant fluororubber end face sealing gasket seals the contact surface between the flange end face of the heating end and the inner wall of the inner furnace body axially. Utilizing the excellent elasticity and high-temperature resistance of fluororubber, it undergoes elastic deformation under the action of bolt preload, filling the microscopic unevenness of the contact surface and forming a second reliable sealing defense. The synergistic effect of the dual sealing structure significantly improves the sealing reliability of the connection between the heating element and the inner furnace body. Even under long-term high temperature and high pressure operating conditions, it can effectively prevent heat transfer oil leakage, thereby further enhancing the explosion-proof safety of the heat transfer oil furnace.

[0013] Preferably, the porous ceramic filter layer within the isolation chamber is fitted to the outer side of the inner furnace body. The thickness of the porous ceramic filter layer is 3-5 mm, and the filter layer adopts a gradient pore size structure. The pore size is 0.1-0.2 mm on the side closer to the inner furnace body and 0.2-0.3 mm on the side closer to the outer furnace body. A 10-15 mm flow gap is reserved between the porous ceramic filter layer and the inner wall of the outer furnace body. This design allows the porous ceramic filter layer to fit tightly against the inner furnace body, promptly capturing any heat transfer oil vapor or tiny droplets that may leak from the inner furnace body. The gradient pore size structure design is ingenious. The smaller pore size on the side closer to the inner furnace body can efficiently intercept fine oil mist particles, while the slightly larger pore size on the side closer to the outer furnace body facilitates the downward aggregation of intercepted oil droplets under gravity, while also reducing the resistance to gas flow. The 10-15mm flow gap provides a buffer and flow space for the gas after preliminary treatment by the porous ceramic filter layer, allowing the gas to flow smoothly to other areas of the isolation chamber or subsequent processing devices, further enhancing the explosion-proof isolation effect of the isolation chamber and effectively preventing the heat transfer oil vapor or oil-gas mixture from diffusing to the outside of the furnace body.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. This invention constructs an intrinsically safe isolation system between the heat transfer oil system and the external flammable and explosive environment by adopting a dual physical barrier structure consisting of an inner furnace body and an outer furnace body, and setting a porous ceramic filter layer and an inert gas interface in the sealed isolation chamber formed by the two. It replaces the delayed response mode of traditional equipment that relies on power outage emergency cycles and passive protection, eliminates the risk of forming explosive mixtures after heat transfer oil leakage, and improves the explosion-proof safety level in high-risk scenarios such as pharmaceuticals and chemicals.

[0016] 2. This invention integrates temperature sensors, pressure sensors, and thermal oil leakage sensors, and electrically connects them with the control module to form an intelligent monitoring network, achieving millisecond-level real-time perception and emergency response of the furnace status; it solves the problem of delayed passive protection response in existing explosion-proof thermal oil furnaces. When a minor leak or pressure abnormality occurs, it can immediately cut off the heat source, vent dangerous gases, and replenish inert gas, reducing the false alarm and missed alarm rates and the accident rate, and ensuring the safe operation of the equipment around the clock.

[0017] 3. This invention achieves energy cascade utilization and effectively reduces overall energy consumption by setting a waste heat recovery heat exchanger at the liquid outlet and using spiral guide vanes to extend the flow path of the cold medium, fully absorbing the waste heat of the high-temperature heat transfer oil for medium preheating; at the same time, by setting a double sealing structure at the connection between the heating element and the inner furnace body, combined with the adsorption and blocking effect of the porous ceramic filter layer with gradient pore size on oil mist, the sealing reliability is improved while the service life of the equipment is extended, achieving a balance between safety performance and economic benefits. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the isolated explosion-proof thermal oil furnace of the present invention;

[0019] Figure 2 This is a front view of the isolated explosion-proof thermal oil furnace of the present invention;

[0020] Figure 3 This is a cross-sectional view of the furnace body assembly of the isolated explosion-proof thermal oil furnace of the present invention;

[0021] Figure 4 For the present invention Figure 3 The front view;

[0022] Figure 5 For the present invention Figure 4 Sectional view at point A in the middle;

[0023] Figure 6 For the present invention Figure 4 Sectional view at point B.

[0024] In the diagram: 1. Frame; 201. Inner furnace body; 2011. Liquid inlet; 2012. Liquid outlet; 202. Outer furnace body; 2021. Inert gas interface; 2022. Flow control valve; 2023. Inert gas concentration sensor; 2024. Baffle plate; 2025. Safety vent pipe; 2026. Dual-control valve; 203. Isolation chamber; 2031. Liquid collection tank; 2032. Drain valve; 204. Porous ceramic filter layer; 3. Heating element; 301. Heating end; 30 2. Wiring terminal; 303. Isolation junction box; 4. Thermal oil circulation pump; 5. Control cabinet; 501. Temperature sensor; 5011. High-temperature protective sleeve; 502. Pressure sensor; 503. Thermal oil leakage sensor; 601. Outer sleeve; 602. Inner heat exchange tube; 603. Cold medium inlet; 604. Preheating medium outlet; 605. Annular preheating chamber; 606. Spiral guide vane; 701. Threaded sealing groove; 702. End face sealing gasket; 703. PTFE sealing tape. Detailed Implementation

[0025] Please see Figures 1 to 6 This invention provides an isolated explosion-proof thermal oil furnace, the technical solution of which is as follows:

[0026] An explosion-proof thermal oil furnace with isolation features includes a frame 1, a furnace body assembly, a heating element 3, a thermal oil circulation pump 4, and a control cabinet 5. The furnace body assembly is mounted on the frame 1 and includes an inner furnace body 201 and an outer furnace body 202. A sealed isolation chamber 203 is formed between the inner furnace body 201 and the outer furnace body 202. A porous ceramic filter layer 204 is provided in the isolation chamber 203. The porous ceramic filter layer 204 is attached to the outer side of the inner furnace body 201 and has a thickness of 4 mm. The filter layer adopts a gradient pore size structure, with a pore size of 0.13 mm on the side near the inner furnace body 201 and a pore size of 0.21 mm on the side near the outer furnace body 202. An 11mm flow gap is reserved between the heating element 3 and the inner wall of the outer furnace body 202. The heating element 3 is provided with a heating end 301 and a terminal 302. The heating end 301 is threadedly connected to the inner furnace body 201. An isolation junction box 303 is installed on the terminal 302. The threaded connection between the heating end 301 of the heating element 3 and the inner furnace body 201 is provided with a double sealing structure. The double sealing structure includes a threaded sealing groove 701 and an end face sealing gasket 702. The threaded sealing groove 701 is opened at the root of the thread of the heating end 301. A PTFE sealing strip 703 is embedded in the threaded sealing groove 701. The end face sealing gasket 702 is made of high-temperature resistant fluororubber and is clamped to the flange end of the heating end 301. Between the outer furnace body 202 and the inner wall of the inner furnace body 201, the bottom and right end faces of the inner furnace body 201 are respectively provided with a liquid inlet 2011 and a liquid outlet 2012. The heat transfer oil circulation pump 4 and the control cabinet 5 are both mounted on the frame 1. The liquid inlet 2011 is connected to the heat transfer oil circulation pump 4 through a pipe. The outer furnace body 202 is provided with an inert gas interface 2021. The inert gas interface 2021 is opened on the side wall of the outer furnace body 202 and is connected to the isolation chamber 203. The control cabinet 5 is provided with a monitoring module and a control module. The monitoring module includes a temperature sensor 501, a pressure sensor 502 and a heat transfer oil leakage sensor 503. The heating element 3, temperature sensor 501, pressure sensor 502 and heat transfer oil leakage sensor 503 are also provided. All components are electrically connected to the control module. A flow control valve 2022 is installed at the inert gas interface 2021. An inert gas concentration sensor 2023 is installed inside the isolation chamber 203. Both the flow control valve 2022 and the inert gas concentration sensor 2023 are electrically connected to the control module. A guide plate 2024 is provided between the inert gas interface 2021 and the porous ceramic filter layer 204. The guide plate 2024 is fixed to the outside of the inner furnace body 201 and fitted to the porous ceramic filter layer 204. Guide holes are evenly distributed on the surface of the guide plate 2024. A safety vent pipe 2025 is installed on the outer furnace body 202. One end of the safety vent pipe 2025 is connected to the isolation chamber 203, and the other end extends to a safe outdoor area.The safety vent pipe 2025 is equipped with a dual-control valve 2026, which is electrically connected to the control module. The temperature sensor 501 is coaxially embedded in the heating end 301, and a high-temperature resistant protective sleeve 5011 is fitted over the outside of the temperature sensor 501. The pressure sensor 502 is located in the isolation chamber 203, near the interface of the safety vent pipe 2025. The heat transfer oil leakage sensor 503 is located at the bottom of the isolation chamber 203, directly below the inner furnace body 201. A liquid collection tank 2031 is also provided at the bottom of the isolation chamber 203, and the liquid collection tank 2031 corresponds to the heat transfer oil leakage sensor 503. The liquid collection tank 2031 is equipped with a drain valve 2032 at its bottom, which extends through the outer furnace body 202 to the outside. A waste heat recovery heat exchanger is located at the liquid outlet 2012. The waste heat recovery heat exchanger includes an outer sleeve 601 and an inner heat exchange tube 602. The inner heat exchange tube 602 is connected to the liquid outlet 2012. The outer sleeve 601 is fitted over the inner heat exchange tube 602. The outer sleeve 601 has a cold medium inlet 603 and a preheating medium outlet 604 at its two ends, respectively. An annular preheating cavity 605 is formed between the outer sleeve 601 and the inner heat exchange tube 602. A spiral guide vane 606 is provided inside the annular preheating cavity 605.

[0027] When working, please refer to Figures 1 to 6In production scenarios involving flammable and explosive media, such as pharmaceuticals or chemicals, the workflow of this isolated explosion-proof thermal oil furnace begins with a remote start command from the central control room. Upon receiving the signal, the control module first performs a self-check on all sensors. After confirming no abnormalities, it opens the flow control valve 2022 at the inert gas interface 2021, filling the sealed isolation chamber 203, composed of the inner furnace body 201 and the outer furnace body 202, with high-purity nitrogen. The nitrogen diffuses evenly through the guide plate 2024 and then passes through the porous ceramic filter layer 204 with gradient pore sizes, removing the original... Air is completely replaced by the safety vent pipe 2025 until the inert gas concentration sensor 2023 detects that the oxygen concentration has dropped below 2%. The control module then adjusts the flow control valve 2022 to a maintaining state, ensuring that the isolation chamber 203 is always kept in a slightly positive pressure inert atmosphere, eliminating the risk of explosion at its source. Subsequently, the heat transfer oil circulation pump 4 starts, and low-temperature heat transfer oil enters from the inlet 2011 at the bottom of the inner furnace body 201. After being heated by the heating element 3 heating end 301 threadedly connected inside the inner furnace body 201, it flows out from the outlet 2012. The inner heat exchange tube 602 of the waste heat recovery heat exchanger is connected to the deionized water from the pure water station. Simultaneously, deionized water from the pure water station enters the annular preheating chamber 605 through the cold medium inlet 603. Guided by the spiral guide vanes 606, it spirals along the outer wall of the inner heat exchange tube 602, fully absorbing the waste heat of the high-temperature heat transfer oil. This water is then used as a preheating medium for reactor cleaning or boiler makeup water, achieving cascaded energy utilization. Meanwhile, the temperature sensor 501 embedded in the heating end 301 monitors the heat transfer oil temperature in real time and feeds the signal back to the control module. The PID algorithm precisely adjusts the heating element... The power of component 3 ensures that the oil outlet temperature remains stable at the process requirement of 180℃. Throughout the entire operation, the monitoring module maintains millisecond-level data acquisition. When the inner furnace body 201 develops micro-cracks due to long-term thermal aging, causing heat transfer oil vapor to seep into the isolation chamber 203, the porous ceramic filter layer 204 first adsorbs and blocks the diffusion of oil mist. The condensed droplets fall into the liquid collection tank 2031 located directly below the inner furnace body 201. The heat transfer oil leakage sensor 503 immediately detects the presence of organic matter and sends a signal to the control module. The control module is at 0.Within 5 seconds, the system executes a series of interlocking actions, including cutting off the power to heating element 3, opening the dual-control valve 2026 of the safety vent pipe 2025 to release hazardous gas to the outdoor flare system for treatment, increasing the nitrogen supply for forced purging and dilution, issuing an audible and visual alarm, and uploading fault information to the DCS control room. When pressure sensor 502 detects a sharp increase in pressure in isolation chamber 203 due to an abnormality in the circulation pipeline, exceeding the set threshold, the control module will also immediately open the dual-control valve 2026 for pressure relief protection, automatically closing it after the pressure returns to normal. This is also relevant when changing drug batches or performing other related actions. During major maintenance, the control module executes a shutdown procedure to first cut off heating element 3. The circulating pump continues to run until the heat transfer oil cools down. Then, the nitrogen flow rate is increased to completely replace the isolation chamber 203. Operators check and drain any accumulated liquid in the collection tank 2031 through the drain valve 2032 that penetrates the outer furnace body 202. Compressed air can be connected to perform reverse purging and cleaning of the porous ceramic filter layer 204 to restore its permeability. After maintenance, the drain valve 2032 and the dual-control valve 2026 are closed, and the inert atmosphere establishment process is repeated to resume production.

[0028] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. An isolated explosion-proof thermal oil furnace, characterized in that, The system includes a frame (1), a furnace body assembly, a heating element (3), a heat transfer oil circulation pump (4), and a control cabinet (5). The furnace body assembly is mounted on the frame (1). The furnace body assembly includes an inner furnace body (201) and an outer furnace body (202). A sealed isolation chamber (203) is formed between the inner furnace body (201) and the outer furnace body (202). A porous ceramic filter layer (204) is provided in the isolation chamber (203). The heating element (3) is provided with a heating end (301) and a wiring terminal (302). The heating end (301) is threaded into the inner furnace body (201). An isolation junction box (303) is installed on the wiring terminal (302). An inlet (2011) and a liquid inlet (2012) are respectively provided on the bottom and right end face of the inner furnace body (201). The outlet (2012), the heat transfer oil circulation pump (4) and the control cabinet (5) are both installed on the frame (1), the inlet (2011) is connected to the heat transfer oil circulation pump (4) through a pipe, the outer furnace body (202) is provided with an inert gas interface (2021), the inert gas interface (2021) is opened on the side wall of the outer furnace body (202) and is connected to the isolation chamber (203), the control cabinet (5) is provided with a monitoring module and a control module, the monitoring module includes a temperature sensor (501), a pressure sensor (502) and a heat transfer oil leakage sensor (503), the heating element (3), the temperature sensor (501), the pressure sensor (502) and the heat transfer oil leakage sensor (503) are all electrically connected to the control module; The heat transfer oil leakage sensor (503) is located at the bottom of the isolation chamber (203) and directly below the inner furnace body (201). The bottom of the isolation chamber (203) is also provided with a liquid collection tank (2031). The liquid collection tank (2031) is correspondingly provided with the heat transfer oil leakage sensor (503). The bottom of the liquid collection tank (2031) is provided with a drain valve (2032). The drain valve (2032) extends through the outer furnace body (202) to the outside.

2. The explosion-proof thermal oil furnace of the isolation type according to claim 1, characterized in that: A flow control valve (2022) is provided at the inert gas interface (2021), and an inert gas concentration sensor (2023) is provided in the isolation chamber (203). Both the flow control valve (2022) and the inert gas concentration sensor (2023) are electrically connected to the control module. A guide plate (2024) is provided between the inert gas interface (2021) and the porous ceramic filter layer (204). The guide plate (2024) is fixed on the outside of the inner furnace body (201) and is attached to the porous ceramic filter layer (204). Multiple guide holes are opened on the surface of the guide plate (2024), and the multiple guide holes are evenly distributed on the surface of the guide plate (2024).

3. The explosion-proof thermal oil furnace of the isolation type according to claim 2, characterized in that: A safety vent pipe (2025) is installed on the outer furnace body (202). One end of the safety vent pipe (2025) is connected to the isolation chamber (203), and the other end extends to the outdoor safety area. A dual-control valve (2026) is provided on the safety vent pipe (2025), and the dual-control valve (2026) is electrically connected to the control module.

4. The explosion-proof thermal oil furnace of the isolation type according to claim 3, characterized in that: The temperature sensor (501) is coaxially embedded in the heating end (301), and a high-temperature resistant protective sleeve (5011) is fitted on the outside of the temperature sensor (501). The pressure sensor (502) is located in the isolation chamber (203) and close to the interface of the safety vent pipe (2025).

5. The explosion-proof thermal oil furnace of the isolation type according to claim 1, characterized in that: A waste heat recovery heat exchanger is provided at the liquid outlet (2012). The waste heat recovery heat exchanger includes an outer tube (601) and an inner heat exchange tube (602). The inner heat exchange tube (602) is connected to the liquid outlet (2012). The outer tube (601) is sleeved outside the inner heat exchange tube (602). The two ends of the outer tube (601) are respectively provided with a cold medium inlet (603) and a preheating medium outlet (604). An annular preheating cavity (605) is formed between the outer tube (601) and the inner heat exchange tube (602). A spiral guide vane (606) is provided in the annular preheating cavity (605).

6. The explosion-proof thermal oil furnace of the isolation type according to claim 1, characterized in that: The heating element (3) has a double sealing structure at the threaded connection between the heating end (301) and the inner furnace body (201). The double sealing structure includes a threaded sealing groove (701) and an end face sealing gasket (702). The threaded sealing groove (701) is opened at the root of the thread of the heating end (301). The threaded sealing groove (701) is embedded with a PTFE sealing strip (703). The end face sealing gasket (702) is made of high-temperature resistant fluororubber. The end face sealing gasket (702) is sandwiched between the flange end face of the heating end (301) and the inner wall of the inner furnace body (201).

7. The explosion-proof thermal oil furnace of the isolation type according to claim 1, characterized in that: The porous ceramic filter layer (204) in the isolation chamber (203) is attached to the outer side of the inner furnace body (201). The thickness of the porous ceramic filter layer (204) is 3-5mm. The filter layer adopts a gradient pore size structure, with a pore size of 0.1-0.2mm on the side near the inner furnace body (201) and a pore size of 0.2-0.3mm on the side near the outer furnace body (202). A flow gap of 10-15mm is reserved between the porous ceramic filter layer (204) and the inner wall of the outer furnace body (202).

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