A high cold-heat shock resistant glass tube heater

Abstract

The application relates to the technical field of heaters, and particularly discloses a high cold-heat shock resistance glass tube heater, which comprises a heater, the heater comprises a heating wire, an inner layer glass tube sleeved outside the heating wire and rubber caps sleeved at two ends of the inner layer glass tube, the two ends of the heating wire are connected with outgoing wires, a through hole is formed in one end of the rubber cap away from the inner layer glass tube, the outgoing wires are extended out of the rubber cap through the through hole, an outer layer glass tube is coaxially sleeved outside the inner layer glass tube, one end of the rubber cap is inserted into the outer layer glass tube, a metal protection tube is coaxially sleeved on the outer layer glass tube, and the inner surface of the metal protection tube is in abutment with the outer surface of the outer layer glass tube. By arranging the metal protection tube, the water baffle above the glass tube heater can be cancelled, the defrosting water droplets can be isolated from falling on the glass tube, the cold-heat shock resistance of the glass tube heater is effectively increased, and the volume of the heater is reduced. The application has the effect of reducing the overall volume of the glass tube heater.

Description

Technical Field

[0001] This application relates to the field of heater technology, and in particular to a glass tube heater with high resistance to thermal shock. Background Technology

[0002] During the operation of refrigeration appliances such as refrigerators and freezers, the core component, the heat exchanger, condenses moisture from the air into frost, which adheres to the heat exchanger. When this frost accumulates to a certain thickness, it affects the heat exchanger's heat exchange capacity, thus impacting the refrigeration appliance's cooling capacity. Therefore, to ensure the normal operation of refrigeration appliances, it is necessary to periodically defrost the frost on the heat exchanger using heating.

[0003] Currently, defrosting is typically achieved using a glass tube heater located below the heat exchanger. During defrosting, the melted defrosting water drips downwards. If it drips directly onto the glass tube heater, the glass tube may crack due to rapid cooling, thus affecting the safety and lifespan of the equipment.

[0004] In related technologies, in order to prevent the glass tube heater from breaking when it comes into contact with water, a water baffle is usually installed above the glass tube heater. The water baffle is umbrella-shaped and covers the glass tube heater, and the width of the water baffle is much larger than the diameter of the glass tube heater, so as to ensure that defrosting water will not drip onto the glass tube.

[0005] In practical use, it has been found that in recent years, with the development of the refrigerator and freezer industry, increasing the effective volume ratio of refrigerators and freezers has become a new development trend. Under this trend, the thickness of heat exchangers is getting thinner and thinner, to the point that after the glass tube heater structure is fitted with a baffle plate, it not only hinders the circulation of cooling air inside the refrigeration appliance, but also increases the overall volume of the glass tube heater, making it unable to meet the requirements of new refrigeration appliances. Utility Model Content

[0006] In order to reduce the overall volume of the glass tube heater, this application provides a glass tube heater with high resistance to thermal shock, which has the effect of reducing the overall volume of the glass tube heater.

[0007] The high thermal shock resistant glass tube heater provided in this application adopts the following technical solution: A high-temperature and thermal shock resistant glass tube heater includes a heater, which comprises a heating wire, an inner glass tube sleeved around the heating wire, and rubber caps sleeved at both ends of the inner glass tube. Both ends of the heating wire are connected to lead wires. The rubber caps have a through hole at the end away from the inner glass tube, through which the lead wires extend out of the rubber caps. An outer glass tube is coaxially sleeved around the inner glass tube, and one end of the rubber caps is inserted into the outer glass tube. A metal protective tube is coaxially sleeved on the outer glass tube, and the inner surface of the metal protective tube abuts against the outer surface of the outer glass tube.

[0008] By adopting the above technical solution, the lead wire is connected to the power supply, which causes the heating wire to heat up. The heat is transferred to the inner glass tube and then to the outer glass tube. The heat on the outer glass tube is transferred to the metal protective tube through heat conduction to reduce the temperature of the glass tube. When the heat on the metal protective tube dissipates to the heat exchanger, the frost on the heat exchanger melts and produces defrosting water, which then drips onto the glass tube heater. At this time, the metal protective tube can not only prevent the defrosting water from dripping directly onto the outer glass tube, but also reduce the overall size of the heater, making it easier to adapt to thinner heat exchangers.

[0009] Optionally, the outer surface of the metal protective tube is provided with spiral heat dissipation fins, which are coaxially sleeved on the metal protective tube along the axial direction of the metal protective tube.

[0010] By adopting the above technical solution, the spiral heat dissipation fins increase the contact area with air, thereby accelerating the heat dissipation rate of the metal protective tube and reducing the surface temperature.

[0011] Optionally, the two ends of the metal protective tube are bent into a flared shape and extend toward the rubber cap.

[0012] By adopting the above technical solution, when installing the metal protective tube, the flared shape at the end of the metal protective tube helps to prevent the end face of the metal protective tube from scratching the surface of the outer glass tube, which is beneficial to protecting the appearance of the outer glass tube.

[0013] Optionally, a connecting terminal is provided inside the rubber cap. The connecting terminal is sleeved outside the connection between the lead wire and the heating wire. One end of the connecting terminal is inserted into the through hole, and the other end of the connecting terminal extends into the inner glass tube. A fixing gasket is coaxially provided on the connecting terminal, and the fixing gasket abuts against the end of the inner glass tube.

[0014] By adopting the above technical solution, the connecting terminal forms a protective wrap around the connection between the lead wire and the heating wire, reducing the risk of the lead wire falling off or making poor contact due to vibration; at the same time, the fixing gasket abuts against the inner glass tube, and together with the fixing of the rubber cap, it can effectively limit the axial displacement of the heating wire and improve the stability of the heating wire.

[0015] Optionally, the inner wall of the rubber cap is coaxially provided with an installation hole, the diameter of which is adapted to the outer diameter of the inner glass tube, the end of the inner glass tube extends into the installation hole, the fixing gasket is embedded in the installation hole, and the fixing gasket is sandwiched between the inner glass tube and the bottom wall of the installation hole.

[0016] By adopting the above technical solution, the relative slippage between the fixing shim and the end face of the inner glass tube is effectively reduced by fixing the fixing shim in the mounting hole, thereby reducing the deformation and movement of the heating wire and further improving the stability of the heating wire.

[0017] Optionally, a connecting tube is coaxially provided at the end of the rubber cap away from the outer glass tube, the connecting tube is connected to the through hole, the lead wire is inserted into the connecting tube, and a sealing cable tie is provided on the outside of the connecting tube.

[0018] By adopting the above technical solution, the connecting tube provides support and protection for the lead wire; the sealing cable tie is tied to the outside of the connecting tube to achieve a seal; when the sealing cable tie is tightened, the gap between the lead wire and the inner wall of the connecting tube can be eliminated, effectively preventing external moisture from entering the inner wall of the glass tube.

[0019] Optionally, the rubber cap has an exhaust groove along the axial direction, the exhaust groove connects the space formed by the inner glass tube and the outer glass tube, and the rubber cap is provided with a one-way valve at the end of the exhaust groove, the one-way valve only allows the gas inside the heater to overflow to the outside.

[0020] By adopting the above technical solution, the one-way valve effectively reduces the entry of external water vapor into the exhaust groove. The cooperation between the exhaust groove and the one-way valve facilitates the release of high-pressure gas generated between the outer and inner glass tubes due to temperature rise, reducing the risk of glass tube breakage due to excessive gas pressure and effectively improving the impact resistance of the glass tube in alternating hot and cold environments.

[0021] Optionally, the rubber cap is coaxially provided with a vent hole, which is located between the through hole and the mounting hole. The diameter of the vent hole is smaller than the diameter of the fixing gasket and larger than the diameter of the through hole. The fixing gasket is provided with a vent hole, which is connected to the inner glass tube. A connecting groove is provided on the inner wall of the vent hole, which is located between the exhaust groove and the vent hole and is connected to the exhaust groove.

[0022] By adopting the above technical solution, and by setting up air guide holes and connecting grooves, the high-pressure gas inside the inner glass tube can also be discharged from the exhaust groove, realizing the gas pressure regulation of the double-layer cavity. By unifying the exhaust path through the exhaust groove and other means, the gas release efficiency is improved.

[0023] Optionally, the outer surface of the outer glass tube is coated with a heat-conducting coating.

[0024] By adopting the above technical solution, it is beneficial to reduce the thermal resistance between the outer glass tube and the metal protective tube and improve the heat transfer efficiency.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The lead wire connects to the power supply, causing the heating wire to heat up. The heat is transferred to the inner glass tube and then to the outer glass tube. The heat on the outer glass tube is transferred to the metal protective tube through heat conduction to reduce the temperature of the glass tube. When the heat on the metal protective tube dissipates to the heat exchanger, the frost on the heat exchanger melts and produces defrosting water, which then drips onto the glass tube heater. At this time, the metal protective tube not only prevents the defrosting water from dripping directly onto the outer glass tube, but also reduces the overall size of the heater, making it easier to adapt to thinner heat exchangers. 2. The spiral heat dissipation fins increase the contact area with air, accelerating the heat dissipation rate of the metal protective tube and thus reducing the surface temperature; 3. The one-way valve effectively reduces the entry of external moisture into the exhaust channel. The combination of the exhaust channel and the one-way valve facilitates the release of high-pressure gas generated between the outer and inner glass tubes due to temperature rise, reducing the risk of glass tube breakage due to excessive gas pressure and effectively improving the impact resistance of the glass tube in alternating hot and cold environments. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the high thermal shock resistant glass tube heater of this application; Figure 2 This is a cross-sectional view of the high thermal shock resistant glass tube heater of this application; Figure 3 yes Figure 2 Enlarged view of A in the middle; Figure 4 This is an exploded view of a one-way valve.

[0027] Reference numerals: 1. Heater; 101. Heating wire; 102. Inner glass tube; 103. Rubber cap; 2. Lead wire; 3. Through hole; 4. Outer glass tube; 5. Metal protective tube; 6. Heat dissipation fins; 7. Connecting terminal; 8. Fixing gasket; 9. Mounting hole; 10. Connecting tube; 11. Sealing cable tie; 12. Exhaust groove; 13. One-way valve; 131. Valve body; 132. Valve core; 14. Air guide hole; 15. Vent hole; 16. Connecting groove; 17. Insertion part; 18. Through hole; 19. Snap-fit ​​hole; 20. Groove. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0029] This application discloses a glass tube heater with high resistance to thermal shock, referring to... Figure 1 The device includes a heater 1, and a metal protective tube 5 is coaxially sleeved on the outer wall of the heater 1. The inner surface of the metal protective tube 5 abuts against the outer surface of the heater 1. The metal protective tube 5 can prevent defrosting water from dripping directly onto the glass tube. Compared with using a baffle to isolate defrosting water, using the metal protective tube 5 effectively reduces the overall volume of the heater 1, improves the resistance of the glass tube heater 1 to thermal shock, and makes it easier to adapt to thinner heat exchangers.

[0030] Reference Figure 1 and Figure 2 The heater 1 includes a heating wire 101, an inner glass tube 102, and a rubber cap 103. The middle section of the heating wire 101 is spirally wound in a circular shape and passes through the inner glass tube 102. Both ends of the heating wire 101 are twisted into a straight rope shape to form a non-heating end. There are two rubber caps 103, which are respectively fitted onto the two ends of the inner glass tube 102. The two ends of the heating wire 101 are respectively connected to lead wires 2 that supply power to the heating wire 101. The end of the rubber cap 103 away from the inner glass tube 102 has a through hole 3 coaxially. The end of the lead wire 2 away from the heating wire 101 passes through the through hole 3, and the outer surface of the lead wire 2 abuts against the inner wall of the through hole 3. The lead wire 2 extends out of the rubber cap 103 through the through hole 3.

[0031] Reference Figure 2 An outer glass tube 4 is coaxially sleeved around an inner glass tube 102. The length of the inner glass tube 102 is greater than the length of the outer glass tube 4. The inner glass tube 102 and the outer glass tube 4 are concentric and respectively fixed to a rubber cap 103. An insertion part 17 is integrally formed on the end face of the rubber cap 103 near the inner glass tube 102. The insertion part 17 is inserted into the gap between the outer glass tube 4 and the opening of the inner glass tube 102. One end of the inner glass tube 102 near the rubber cap 103 is coaxially inserted into the insertion part 17. A metal protective tube 5 is sleeved on the outside of the outer glass tube 4. Both ends of the metal protective tube 5 are bent outward to form a flared shape and extend towards the rubber cap 103. This is to prevent the end face of the metal protective tube 5 from scratching the surface of the outer glass tube 4 when the metal protective tube 5 is installed, so as to protect the appearance of the outer glass tube 4.

[0032] Reference Figure 1The outer surface of the metal protective tube 5 is welded and fixed with heat dissipation fins 6. The heat dissipation fins 6 are made of metal and have a spiral strip structure. The heat dissipation fins 6 are coaxially sleeved on the outer circumference of the metal protective tube 5 along the axial direction. The spiral heat dissipation fins 6 can be stably wound and fixed on the metal protective tube 5, which can absorb the heat on the metal protective tube 5 and dissipate it to the heated object, thereby improving the heat dissipation efficiency of the metal protective tube 5.

[0033] Reference Figure 2 The rubber cap 103 has a mounting hole 9 coaxially formed on its inner bottom wall to accommodate the end of the inner glass tube 102. The mounting hole 9 extends to the insertion part 17 and communicates with the inner cavity of the outer glass tube 4. The inner diameter of the mounting hole 9 matches the outer diameter of the inner glass tube 102. The length of the inner glass tube 102 extending out of the outer glass tube 4 is less than the depth of the mounting hole 9. The rubber cap 103 has a connecting terminal 7. One end of the connecting terminal 7 is inserted into the through hole 3 and abuts against the inner wall of the through hole 3. The other end of the connecting terminal 7 is inserted into the inner glass tube 102. The connecting terminal 7 is connected to the connection between the lead wire 2 and the heating wire 101 by riveting, which facilitates the protection of the lead wire 2 and the heating wire 101 and reduces the possibility of poor contact between them.

[0034] Reference Figure 2 and Figure 3 A fixing gasket 8 is fitted on the outer wall of the middle section of the connecting terminal 7. The plane of the fixing gasket 8 is perpendicular to the axis of the connecting terminal 7. The diameter of the fixing gasket 8 is between the outer diameter and the inner diameter of the inner glass tube 102, and the outer diameter of the fixing gasket 8 is slightly larger than the inner diameter of the mounting hole 9. The two end planes of the fixing gasket 8 abut against the inner bottom wall of the mounting hole 9 and the end of the inner glass tube 102, respectively. During installation, the fixing gasket 8 is sandwiched between the inner wall of the mounting hole 9 and the inner glass tube 102, which can reduce the movement of the fixing gasket 8, thereby contributing to the stability of the position of the heating wire 101.

[0035] Reference Figure 1 and Figure 2 The end of the rubber cap 103 away from the outer glass tube 4 is integrally formed with a connecting tube 10. The connecting tube 10 is made of rubber and is cylindrical. The connecting tube 10 is coaxial with the rubber tube. A through hole 18 is opened in the connecting tube 10 along the axial direction. The through hole 18 is concentric with the through hole 3. The lead wire 2 passes through the through hole 18 and extends into the through hole 3 to connect with the heating wire 101. The connecting tube 10 facilitates the support and protection of the lead wire 2, reduces the possibility of tilting and shaking, and helps to improve the stability of the lead wire 2. A sealing strap 11 is fitted on the outer wall of the connecting tube 10. By tightening the sealing strap 11, the gap between the lead wire 2 and the inner wall of the through hole 18 can be reduced, which facilitates the isolation of the internal space and external space of the glass tube and reduces the entry of external moisture into the glass tube.

[0036] Reference Figure 2 The rubber cap 103 has an exhaust groove 12 along the axial direction. The exhaust groove 12 extends to the inner wall of the insertion part 17 and communicates with the space formed by the inner glass tube 102 and the outer glass tube 4. The rubber cap 103 has a snap-fit ​​hole 19 at the end of the exhaust groove 12 away from the outer glass tube 4. The snap-fit ​​hole 19 communicates with the exhaust groove 12. A one-way valve 13 is installed on the inner wall of the snap-fit ​​hole 19. The one-way valve 13 only allows the gas inside the glass tube to be discharged to the outside.

[0037] Reference Figure 2 and Figure 3 A vent hole 14 is coaxially formed inside the rubber cap 103. The vent hole 14 is located between the through hole 3 and the mounting hole 9. The diameter of the vent hole 14 is larger than that of the through hole 3 and smaller than that of the mounting hole 9. A connecting groove 16 is formed on the inner wall of the vent hole 14 near the exhaust groove 12. The connecting groove 16 is connected to both the vent hole 14 and the exhaust groove 12. A plurality of vent holes 15 are formed on the fixing gasket 8. When the fixing gasket 8 abuts against the bottom of the mounting hole 9, the gas in the inner glass tube 102 is sequentially introduced into the exhaust groove 12 through the vent holes 15, the vent hole 14, and the connecting groove 16.

[0038] When the temperature and pressure of the gas inside the inner glass tube 102 or the outer glass tube 4 increase, the excess gas can overflow from the exhaust groove 12 and the one-way valve 13, which helps to maintain the stability of the gas pressure inside the glass tube; at the same time, it can also reduce the ingress of external water vapor into the glass tube.

[0039] Refer to 2 and Figure 4 The one-way valve 13 includes a valve body 131 and a valve core 132. The outer circumferential surface of the valve body 131 is snapped and fixed to the inner wall of the snap-fit ​​hole 19. The valve core 132 is an umbrella-shaped structure made of elastic rubber. The umbrella handle of the valve core 132 passes through the inside of the valve body 131. Grooves 20 are provided on both sides of the umbrella handle of the valve core 132. The inner circumferential surface of the umbrella-shaped cap of the valve core 132 abuts against the inner plane of the valve body 131 to form a seal. When the internal air pressure rises to a threshold, the valve core 132 deforms. At this time, a gap is formed between the contact surface of the valve core 132 and the valve body 131, and the internal gas overflows from the groove 20 and the gap. When the internal air pressure drops below the threshold, the valve core 132 returns to its original shape, that is, the deformation disappears, and the valve core 132 fits against the inner plane of the valve body 131 to form a sealing structure, which facilitates the isolation of external air or water vapor.

[0040] The outer wall of the outer glass tube 4 is coated with a heat-conducting coating. The coating is preferably a transparent color that facilitates the transmission of infrared radiation. The coating can reduce the thermal resistance between the outer glass tube 4 and the metal protective tube 5, which is beneficial to improving the heat transfer efficiency.

[0041] The implementation principle of a high thermal shock resistant glass tube heater disclosed in this application embodiment is as follows: When the lead wire 2 is energized, the heating wire 101 heats up and heats the gas inside the inner glass tube 102. The heat from the inner glass tube 102 is transferred to the outer glass tube 4, and the heat from the surface of the outer glass tube 4 is transferred to the metal protective tube 5 through heat conduction. The metal protective tube 5 can prevent defrosting water from dripping directly onto the outer glass tube 4. The two layers of glass tubes effectively increase the thermal shock resistance of the glass tube heater 1. With this structure, the baffle plate above the glass tube heater 1 can be eliminated, effectively reducing the overall volume of the glass tube heater 1, which is beneficial for adapting to thinner heat exchangers.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A glass tube heater with high resistance to thermal shock, characterized in that: The device includes a heater (1), which includes a heating wire (101), an inner glass tube (102) sleeved outside the heating wire (101), and rubber caps (103) sleeved at both ends of the inner glass tube (102). Both ends of the heating wire (101) are connected to lead wires (2). The rubber cap (103) has a through hole (3) at the end away from the inner glass tube (102). The lead wire extends out of the rubber cap (103) through the through hole (3). An outer glass tube (4) is coaxially sleeved outside the inner glass tube (102). One end of the rubber cap (103) is inserted into the outer glass tube (4). A metal protective tube (5) is coaxially sleeved on the outer glass tube (4). The inner surface of the metal protective tube (5) abuts against the outer surface of the outer glass tube (4).

2. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The outer surface of the metal protective tube (5) is provided with a spiral heat dissipation fin (6), which is coaxially sleeved on the metal protective tube (5) along the axial direction of the metal protective tube (5).

3. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The two ends of the metal protective tube (5) are bent to form a flared shape and extend toward the rubber cap (103).

4. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The rubber cap (103) is provided with a connecting terminal (7). The connecting terminal (7) is sleeved on the outside of the connection between the lead wire (2) and the heating wire (101). One end of the connecting terminal (7) is inserted into the through hole (3), and the other end of the connecting terminal (7) extends into the inner glass tube (102). A fixing gasket (8) is coaxially provided on the connecting terminal (7), and the fixing gasket (8) abuts against the end of the inner glass tube (102).

5. The high thermal shock resistant glass tube heater according to claim 4, characterized in that, The rubber cap (103) has a mounting hole (9) coaxially formed on its inner wall. The diameter of the mounting hole (9) is adapted to the outer diameter of the inner glass tube (102). The end of the inner glass tube (102) extends into the mounting hole (9). The fixing gasket (8) is embedded in the mounting hole (9) and is sandwiched between the inner glass tube (102) and the bottom wall of the mounting hole (9).

6. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The rubber cap (103) is coaxially provided with a connecting tube (10) at the end away from the outer glass tube (4). The connecting tube (10) is connected to the through hole (3). The lead wire (2) is inserted into the connecting tube (10). The connecting tube (10) is covered with a sealing cable tie (11).

7. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The rubber cap (103) has an exhaust groove (12) along the axial direction. The exhaust groove (12) connects the space formed by the inner glass tube (102) and the outer glass tube (4). The rubber cap (103) is provided with a one-way valve (13) at the end of the exhaust groove (12). The one-way valve (13) only allows the gas inside the heater (1) to overflow to the outside.

8. The high thermal shock resistant glass tube heater according to claim 7, characterized in that, A vent hole (14) is coaxially formed on the rubber cap (103). The vent hole (14) is located between the through hole (3) and the mounting hole (9). The diameter of the vent hole (14) is smaller than the diameter of the fixing gasket (8) and larger than the diameter of the through hole (3). A vent hole (15) is formed on the fixing gasket (8). The vent hole (14) is connected to the inner glass tube (102) through the vent hole (15). A connecting groove (16) is formed on the inner wall of the vent hole (14). The connecting groove (16) is located between the exhaust groove (12) and the vent hole (14). The connecting groove (16) is connected to the exhaust groove (12).

9. The high thermal shock resistant glass tube heater according to claim 1, characterized in that, The outer surface of the outer glass tube (4) is coated with a heat-conducting coating.

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