Sterilizer anti-dry burning device

Abstract

A sterilizer dry-burn prevention device comprises a heat pipe, a first thermostat, and a second thermostat; one end of the heat pipe is a closed end, the heat pipe is in contact with an electric heating pipe, and the area in contact with the electric heating pipe is a temperature-sensing contact surface X, and the closed end is disposed within a sterilization container; the first thermostat and the second thermostat each have a temperature-sensing portion and a preset temperature threshold, and the temperature thresholds are different; the first thermostat and the second thermostat are both built into the heat pipe, and their respective temperature-sensing portions abut or are adjacent to the temperature-sensing contact surface X; the wires of the first and second thermostats are connected to a control circuit e to form a control unit f, and the control unit f, the electric heating pipe, and an external power supply are connected in series; when the temperature of the electric heating pipe exceeds the temperature threshold of the first thermostat or the second thermostat, the control unit f disconnects the circuit between the external power supply and the electric heating pipe. The present invention can achieve multi-level dry-burn prevention, ensuring the safe use of the sterilization container.

Description

Technical Field

[0001] The invention relates to the field of pressure steam sterilization containers, in particular to a sterilizer dry burning prevention device. Background Art

[0002] Pressure steam sterilization vessels are designed to eliminate bacteria and viruses from sterilized objects, taking advantage of the fact that bacteria and viruses cannot survive under high temperature and pressure. During use, electric heating elements placed within the sterilization chamber heat pre-filled purified water, generating high-temperature, high-pressure steam for sterilization. However, if insufficient water is added or the water in the sterilization chamber is gradually depleted during the sterilization process, continued heating after the heating elements emerge from the water can cause dry-burning. Prolonged dry-burning can easily lead to equipment and safety issues.

[0003] Currently, the temperature switches used in sterilization chambers of sterilization containers on the market are hydraulic expansion switches. These switches utilize the principle that the liquid in a temperature-sensing capsule expands with heat, causing the membrane connected to the capsule to expand or contract. This mechanism, through a lever and other mechanical mechanisms, opens and closes the switch contacts to achieve temperature control. The installation process of these temperature switches can easily cause deformation of the temperature-sensing tube and blockage of the capillary tube, compromising temperature control performance or even causing failure. If the temperature switch fails, the heating element will continue to dry-heat, posing a safety risk. Furthermore, the housing of these hydraulic temperature switches is typically made of 304 stainless steel, which is not resistant to chloride ion corrosion. In some cases where chloride ion exposure cannot be completely avoided or the user's water quality is poor, the housing can corrode and leak, causing the temperature switch to fail or inaccurate control. This can lead to ineffective dry-heat protection or the protection function to trip during normal operation, causing equipment malfunction and safety issues. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the above technology to a certain extent. To this end, one object of the present invention is to provide a sterilizer anti-dry burning device.

[0005] In order to achieve the above-mentioned purpose, the first embodiment of the present invention proposes a sterilizer anti-dry burning device, which is arranged inside a sterilization container, and the bottom of the sterilization container is provided with an electric heating pipe; the anti-dry burning device includes a heat pipe, a first thermostat, a second thermostat and a control unit f; one end of the heat pipe is a closed end, and the other end is an open end, the heat pipe and the electric heating pipe are attached to each other, and the area where the heat pipe and the electric heating pipe are attached to each other is a temperature-sensing contact surface X, the closed end is arranged inside the sterilization container, and the open end is arranged outside the sterilization container; the first thermostat and the second thermostat each have at least one temperature-sensing part and a preset temperature threshold, and the temperature thresholds of the first thermostat and the second thermostat are different; the first thermostat and the second thermostat are both built into the heat conduction tube, and their respective temperature sensing parts are against or adjacent to the inner wall of the temperature sensing contact surface X of the heat conduction tube; the wires of the first thermostat and the second thermostat extend from the open end of the heat conduction tube and are connected to a control circuit e to form a control unit f, and the control unit f, the electric heating tube and the external power supply are connected in series; when the temperature of the electric heating tube exceeds the preset temperature threshold of the first thermostat or the second thermostat, the control unit f disconnects the circuit between the external power supply and the electric heating tube.

[0006] Based on the above design, the first thermostat and the second thermostat realize two-way detection of the heating tube temperature, which can achieve multi-level prevention of dry burning, effectively prevent the electric heating tube from dry burning, and can detect the surface temperature of the electric heating tube in real time and control the power off of the electric heating tube, ensuring the safe use of the sterilization container.

[0007] In addition, the sterilizer anti-dry burning device proposed in the above embodiment of the present invention may also have the following additional technical features:

[0008] The first thermostat is a bimetallic thermostat, and the second thermostat is a temperature sensor; the control circuit e includes a power relay, an MCU microcontroller, and a solid-state relay; the bimetallic thermostat is connected to the low power module of the MCU microcontroller and the coil end of the power relay through a wire to form a first control power supply circuit c; the temperature sensor is connected to the MCU microcontroller through a wire, so that the MCU microcontroller receives information fed back by the temperature sensor, and the output end of the MCU microcontroller is connected to the control end of the solid-state relay to form a second control power supply circuit g; the external power supply, the load end of the power relay, the load end of the solid-state relay, and the electric heating tube are connected in series in sequence to form an electric heating tube working power supply circuit h, and the on / off of the electric heating tube working power supply circuit h is controlled by the first control power supply circuit c and the second control power supply circuit g. When the sterilization container is in the heating process and the water level in the sterilization container is lower than the electric heating tube, the surface temperature of the electric heating tube rises sharply, and the bimetallic temperature controller of the first control power supply circuit c is disconnected, causing the first control power supply circuit c to be disconnected. The coil end of the power relay receives the disconnection signal, and the load end of the power relay is disconnected, causing the working power supply circuit h of the electric heating tube to be disconnected; or the MCU microcontroller of the second control power supply circuit g receives the signal feedback from the temperature sensor. Once the temperature exceeds its preset threshold, the output end of the MCU microcontroller will disconnect the second control power supply circuit g connected to the control end of the solid-state relay. The control end of the solid-state relay receives the disconnection signal, and the load end of the solid-state relay is disconnected, also causing the working power supply circuit h of the electric heating tube to be disconnected. After power failure, the temperature of the electric heating tube gradually drops.

[0009] The second temperature controller is a thin film platinum resistor.

[0010] The solid-state relay is replaced by a thyristor.

[0011] The temperature threshold preset by the second thermostat is lower than the temperature threshold preset by the first thermostat. The thin film platinum resistor has high detection accuracy, can detect temperature in real time, and the temperature value can be set steplessly. In addition, the thin film platinum resistor is very durable and is safer to use at high frequencies.

[0012] The side of the heat pipe corresponding to the open end is bent toward the bottom of the sterilization container to form a bent section. The bent section extends downwardly through the bottom surface of the sterilization container, and the open end of the bent section is sealed with a sealant. The downwardly bent section is immersed in water or other heat dissipation medium to protect the first and second thermostats within the heat pipe from overheating.

[0013] The temperature-sensing contact surface X is a plane, which increases the contact area between the heat-conducting pipe and the electric heating pipe, and the temperature of the electric heating pipe is transferred to the inside of the heat-conducting pipe more quickly.

[0014] The heat conducting tube is a copper tube, and a nickel layer is electroplated on the surface of the copper tube. The copper tube has good thermal conductivity, is easy to bend and form, and can withstand corrosion by chloride ions. By electroplating the nickel layer on the copper tube, its ability to resist acid, alkali and chloride ion corrosion can be further improved.

[0015] The heat conducting pipe and the electric heating pipe are fixedly connected via a clamp.

[0016] It also includes a fixing mechanism, which includes a fixing tube, a joint and a nut; the fixing tube is welded to the bottom surface of the sterilization container, the joint is tightly sleeved on the end of the bent section extending out of the sterilization container, and the lower end of the joint is inserted into the fixing tube, and the outer wall of the joint has a thread; the nut is screwed onto the joint through the thread, and a sealing ring is provided between the nut and the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic structural diagram of a sterilizer anti-dry burning device according to the present invention.

[0018] Figure 2 This is a cross-sectional view of a sterilizer anti-dry burning device of the present invention.

[0019] Figure 3 2 is a circuit diagram of the control unit in the present invention.

[0020] Figure 4 This is a diagram (partial cross-section) of the coordination of the heat pipe and the electric heating pipe in the present invention. DETAILED DESCRIPTION

[0021] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0022] See also Figure 1-2 and Figure 4A sterilization container 200 anti-dry burning device 100 is provided inside the sterilization container 200. The sterilization container 200 has an electric heating pipe 20 at the bottom. The anti-dry burning device 100 includes a heat pipe 1, a first thermostat 2, a second thermostat 3, a control unit f and a fixing mechanism 6. One end of the heat pipe 1 is a closed end 111, and the other end is an open end 121. The heat pipe 1 and the electric heating pipe 20 are attached to each other, and the heat pipe 1 and the electric heating pipe 20 are connected. The area of ​​mutual contact is the temperature-sensing contact surface X, which is a plane. This increases the contact area between the heat pipe 1 and the electric heating pipe 20, and the temperature of the electric heating pipe 20 is transferred to the interior of the heat pipe 1 more quickly. The closed end 111 is located inside the sterilization container 200, and the open end 121 is located outside the sterilization container 200. The closed end 111 is sealed by welding, ensuring that electronic components such as the first thermostat 2 and the second thermostat 3 are separated from water vapor. The heat pipe 1 and the electric heating pipe 20 are fixedly connected by a clamp 7. The heat pipe 1 is preferably a copper pipe, and the surface of the copper pipe is electroplated with a nickel layer. Copper pipes have good thermal conductivity and are easy to bend and form. More importantly, copper pipes can withstand corrosion from chloride ions. In some cases where chloride ions cannot be completely avoided or the user's water quality is poor, copper pipes can withstand chloride ion corrosion very well. Electroplating treatment of the copper pipe can further improve the copper pipe surface's ability to withstand acid, alkali, and chloride ion corrosion. The side of the heat pipe 1 corresponding to the open end 121 is bent toward the bottom of the sterilization container 200 to form a bent section 12. The bent section 12 extends downwardly out of the bottom surface of the sterilization container 200, and the open end 121 of the bent section 12 is sealed by a sealant. The downwardly bent bent section 12 is immersed in water or other heat dissipation medium to protect the first thermostat 2 and the second thermostat 3 in the heat pipe 1 from overheating. Because the surface temperature of the electric heating tube 20 rises sharply within about 2 seconds after being disconnected after dry burning, if this temperature is transferred to the electronic components in the heat pipe 1, it will cause overload and damage to the electronic components. The bent section 12 extends downward into the water or other heat dissipation medium to transfer this part of the heat energy to the water, so that the temperature in the heat pipe 1 does not rise so quickly, which can protect the electronic components and improve the stability of the device. The fixing mechanism 6 includes a fixing tube 61, a joint 62 and a nut 63; the fixing tube 61 is welded to the bottom surface of the sterilization container 200, the joint 62 is tightly sleeved on the end of the bending section 12 extending out of the sterilization container 200, and the lower end of the joint 62 is inserted into the fixing tube 61, and the outer wall of the joint 62 has a thread; the nut 63 is screwed onto the joint 62 through the thread, and a sealing ring 64 is provided between the nut 63 and the joint 62.

[0023] Please refer to Figure 1-2Each of the first and second thermostats 2 and 3 has at least one temperature sensing portion and a preset temperature threshold. The temperature thresholds of the first and second thermostats 2 and 3 are different, with the preset temperature threshold of the second thermostat 3 being lower than that of the first thermostat 2. Both the first and second thermostats 2 and 3 are internally mounted within the heat pipe 1, and their respective temperature sensing portions abut or abut against the inner wall of the heat-sensing contact surface X of the heat pipe 1, closely contacting the lower surface (heat source) of the heat pipe 1. This ensures that the detected temperature is closer to the surface temperature of the electric heating pipe 20. Wires from the first and second thermostats 2 and 3 extend from the open end 121 of the heat pipe 1 and are connected to a control circuit e, forming a control unit f. The control unit f, the electric heating pipe 20, and an external power supply are connected in series. When the temperature of the electric heating pipe 20 exceeds the preset temperature threshold of either the first or second thermostat 2 or 3, the control unit f disconnects the circuit between the external power supply and the electric heating pipe 20. The first thermostat 2 is preferably a bimetallic thermostat, which is highly reliable and can change temperature based on the different temperatures sensed by the metal strips, thereby cutting off the power supply. The second thermostat 3 is a temperature sensor, preferably a thin-film platinum resistor. Thin-film platinum resistors have high detection accuracy, can detect temperature in real time, and can be set steplessly. Thin-film platinum resistors are also durable, suitable for high-frequency operation, and have a longer service life.

[0024] Please refer to Figure 2-3 The control circuit e includes a power relay 4, an MCU, and a solid-state relay 5. The power relay 4 has two coil terminals 41 and two load terminals 42. The bimetallic thermostat is connected to the MCU's low power module (i.e., a 24V power module) and the coil terminal 41 of the power relay 4 via wires to form a first control power circuit c. Specifically, the 24V power module within the MCU, the bimetallic thermostat, the coil terminal of the power relay 4, and the grounding module form the first control power circuit c. The temperature sensor is connected to the MCU via wires, allowing the MCU to receive feedback from the temperature sensor. The output terminal of the MCU is connected to the control terminal of the solid-state relay 5 to form a second control power circuit g. The external power supply, the load terminal 42 of the power relay 4, the load terminal of the solid-state relay 5, and the electric heating tube are connected in series to form the electric heating tube operating power circuit h. The first control power circuit c and the second control power circuit g control the on / off of the electric heating tube operating power circuit h. The solid-state relay 5 can also be replaced by a thyristor.

[0025] Please refer to Figure 2-3When the sterilization container is being heated and the water level in the sterilization container 200 is lower than the electric heating tube 20, the surface temperature of the electric heating tube 20 will rise sharply. The heat conducting tube 1 conducts heat quickly and transfers the heat to the first thermostat 2 and the second thermostat 3. Since the second thermostat 3 uses a thin film platinum resistor, its temperature change will cause its resistance value to change. The MCU microcontroller determines the temperature feedback from the second thermostat 3 by receiving the resistance value. Once the temperature transmitted from the heat conducting tube 1 to the second thermostat 3 exceeds the temperature threshold set by the MCU microcontroller, the MCU microcontroller will cut off the second control power supply circuit g between the microcontroller output terminal (I / O pin, which outputs 5V voltage in this embodiment) and the control terminal of the solid-state relay 5, thereby disconnecting the load terminal of the solid-state relay 5, causing the electric heating tube 2 to be disconnected. 0 is disconnected to prevent the sterilization container from drying out. Because the temperature threshold of the second thermostat 3 set in the single-chip microcomputer is lower than that of the first thermostat 2, the temperature of the electric heating tube 20 first reaches the temperature threshold of the second thermostat 3 when it rises. At this time, the MCU determines that the electric heating tube 20 is in a dry-burning state and disconnects the second control power circuit g. If the second thermostat 3 fails, the surface temperature of the electric heating tube 20 will continue to rise until it reaches the trip temperature of the first thermostat 2 (i.e., the temperature threshold of the first thermostat 2). After the first thermostat 2 trips, the first control power circuit c is disconnected, and no current flows through the coil of the power relay 4. The two load terminals 42 are disconnected due to power loss, and the electric heating tube working power circuit h connected to the electric heating tube 20 is also disconnected. After power is cut off, the temperature of the electric heating tube 20 gradually decreases. The first and second thermostats 2 and 3 provide multi-level protection, effectively preventing the electric heating tube 20 from drying out. They can detect the surface temperature of the electric heating tube 20 in real time and control the power off of the electric heating tube 20, ensuring the safe use of the sterilization container.

[0026] The sterilizer anti-dry burning device 100 of the present invention has high precision, stability, reliability, and corrosion resistance. It has a temperature control switch with both mechanical protection and electronic protection to control the working state of the electric heating tube 20. Anti-dry burning adopts both mechanical and electronic methods, with electronic protection as the first level and mechanical protection as the second level to prevent continuous dry burning or false alarms.

[0027] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A sterilizer anti-dry burning device (100), arranged inside a sterilization container (200), wherein the sterilization container (200) has an electric heating tube (20) at the bottom thereof; characterized in that: The anti-dry burning device (100) comprises a heat pipe (1), a first thermostat (2), a second thermostat (3) and a control unit f; one end of the heat pipe (1) is a closed end (111), and the other end is an open end (121); the heat pipe (1) and the electric heating pipe (20) are in contact with each other, and the area where the heat pipe (1) and the electric heating pipe (20) are in contact with each other is a temperature-sensing contact surface X, and the temperature-sensing contact surface X is a plane; the closed end (111) is arranged inside the sterilization container (200), and the open end (121) is arranged outside the sterilization container (200); the first thermostat (2) and the second thermostat (3) each have at least one temperature-sensing portion and a preset temperature threshold, and the first thermostat (2) The temperature threshold value is different from that of the second thermostat (3); the first thermostat (2) and the second thermostat (3) are both built into the heat pipe (1), and their respective temperature sensing parts are against or adjacent to the inner wall of the temperature sensing contact surface X of the heat pipe (1); the wires of the first thermostat (2) and the second thermostat (3) extend from the open end (121) of the heat pipe (1) and are connected to a control circuit e to form a control unit f, and the control unit f, the electric heating pipe (20) and the external power supply are connected in series; the heat pipe (1) is bent toward the bottom of the sterilization container (200) on one side corresponding to the open end (121) to form a bent section (12), and the bent section (12) passes downward through the bottom surface of the sterilization container (200), and the bent section (12) is immersed in water or other heat dissipation medium; When the temperature of the electric heating tube (20) exceeds a temperature threshold preset by the first thermostat (2) or the second thermostat (3), the control unit f disconnects the circuit between the external power supply and the electric heating tube (20).

2. The sterilizer anti-dry burning device (100) according to claim 1, characterized in that: The first thermostat (2) is a bimetallic thermostat, the second thermostat (3) is a temperature sensor, and a preset temperature threshold of the second thermostat (3) is lower than a preset temperature threshold of the first thermostat (2); The control circuit e comprises a power relay (4), an MCU single-chip computer and a solid-state relay (5); the bimetallic temperature controller is connected to a low power module of the MCU single-chip computer and a coil end (41) of the power relay (4) via a wire to form a first control power supply circuit c; the temperature sensor is connected to the MCU single-chip computer via a wire, and the output end of the MCU single-chip computer is connected to the control end of the solid-state relay (5) to form a second control power supply circuit g; an external power supply, a load end (42) of the power relay (4), a load end of the solid-state relay (5) and an electric heating tube are sequentially connected in series to form an electric heating tube working power supply circuit h, and the on / off of the electric heating tube working power supply circuit h is controlled by the first control power supply circuit c and the second control power supply circuit g.

3. The sterilizer anti-dry burning device (100) according to claim 2, characterized in that: The second temperature controller (3) is a thin film platinum resistor.

4. The sterilizer anti-dry burning device (100) according to claim 2, characterized in that: The solid-state relay (5) is replaced by a thyristor.

5. The sterilizer anti-dry burning device (100) according to claim 1, characterized in that: The open end (121) of the bent section (12) is sealed by a sealant.

6. The sterilizer anti-dry burning device (100) according to claim 1, characterized in that: The heat conducting tube (1) is a copper tube, and a nickel layer is electroplated on the surface of the copper tube.

7. The sterilizer anti-dry burning device (100) according to claim 1, characterized in that: The heat conducting pipe (1) and the electric heating pipe (20) are fixedly connected via a clamp (7).

8. The sterilizer anti-dry burning device (100) according to claim 1, characterized in that: The invention also includes a fixing mechanism (6), wherein the fixing mechanism (6) includes a fixing tube (61), a joint (62) and a nut (63); the fixing tube (61) is welded to the bottom surface of the sterilization container (200), the joint (62) is tightly sleeved on the end of the bending section (12) extending out of the sterilization container (200), and the lower end of the joint (62) is inserted into the fixing tube (61), and the outer wall of the joint (62) has a thread; the nut (63) is screwed onto the joint (62) through the thread, and a sealing ring (64) is provided between the nut (63) and the joint (62).

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