Heating tube, dry-type heater, and water heater

Abstract

Disclosed are a heating tube, a dry heater and a water heater. The heating tube includes a tube body, two heating elements and an insulation sleeve. The tube body has a first end and a second end opposite to the first end; the two heating elements are arranged side by side in the tube body, the two heating elements are electrically connected outside the first end, and each of the two heating elements has a terminal extending out of the second end; and the insulation sleeve is provided outside the first end and is sleeved at parts of the two heating elements extending out of the first end.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This invention claims priority to Chinese Patent Application No. 202410498882.2 and Chinese Patent Application No. 202410498877.1, both filed on April 24, 2024, and Chinese Patent Application No. 202323615740.X, filed on December 28, 2023, the entire content of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present invention relates to the technical field of water heaters, and in particular to a heating tube, a dry heater and a water heater.BACKGROUND

[0003] Dry heaters are used as heating elements in storage-type electric water heaters. Dry heaters generally have a heating tube and a heater sleeve. The heater sleeve is fixed inside the tank, and the heating tube is provided in the heater sleeve. When the heating tube is working, the heating tube is energized to convert electrical energy into thermal energy, and the heat is exchanged with the water in the tank through the heater sleeve, thereby heating the water in the tank.SUMMARY

[0004] The main purpose of the present invention is to propose a heating tube, a dry heater and a water heater, aiming to simplify processing and reduce the risk of wire breakage.

[0005] In order to achieve the above purpose, the heating tube proposed in the present invention comprises a tube body, two heating elements and an insulation sleeve.

[0006] Optionally, a tube body is provided with a first end and a second end opposite to the first end.

[0007] Optionally, two heating elements are provided side by side in the tube body, the two heating elements are electrically connected outside the first end, and each of the two heating elements has a terminal extending out of the second end.

[0008] Optionally, an insulation sleeve is provided outside the first end and is sleeved at a portion of the two heating elements extending out of the first end.

[0009] Optionally, the insulation sleeve is provided with an accommodation cavity and an through hole communicated with the accommodation cavity, the through hole is opposite to the first end, and the two heating elements extend into the accommodation cavity through the through hole and are electrically connected in the accommodation cavity.

[0010] Optionally, an end of the insulation sleeve with the through hole is provided on an outer wall of the tube body, and the insulation sleeve is interference-fitted or bonded with the outer wall of the tube body.

[0011] Optionally, an end of the insulation sleeve with the through hole is connected to an end of the tube body, and the insulation sleeve is fixed to the tube body through an adhesive part.

[0012] Optionally, the insulation sleeve has a straight pipe structure; or an end of the insulation sleeve away from the tube body is tapered.

[0013] Optionally, the insulation sleeve has a box structure, and an end of the insulation sleeve away from the tube body is enclosed.

[0014] Optionally, a peripheral wall of the insulation sleeve is provided with a hollow hole communicated with the accommodation cavity, the insulation sleeve is provided with two through holes, and each of the through holes is provided with the heating element in a passing through manner correspondingly.

[0015] Optionally, the heating tube further comprises an electrical connector, and the electrical connector is installed in the accommodation cavity through the hollow hole to electrically connect the two heating elements.

[0016] Optionally, the heating elements is a resistance wire, and the resistance wire is bent to form two heating sections.

[0017] Optionally, the insulation sleeve is a ceramic piece, a glass piece or a Teflon piece.

[0018] Optionally, the heating elements comprises a heating section, a first lead-out rod and a second lead-out rod.

[0019] Optionally, the heating section is provided in the tube body.

[0020] Optionally, the first lead-out rod has an end connected to the heating section and the other end extending out of the first end.

[0021] Optionally, the second lead-out rod has an end connected to the heating section and the other end extending out the second end to form the terminal.

[0022] Optionally, two first lead-out rods are electrically connected outside the first end, and the insulation sleeve is sleeved outside the two first lead-out rods.

[0023] Optionally, the heating tube further comprises: insulated plugs respectively provided at the first end and the second end of the tube body, the two insulated plugs are sealingly connected to tube openings of the tube body to form a seal cavity, and two ends of the heating element are respectively fixed to the two insulated plugs.

[0024] Optionally, the insulated plug is provided with two positioning holes spaced apart, the two first lead-out rods respectively pass through the two positioning holes located at the first end, the two terminals respectively pass through the two positioning holes located at the second end.

[0025] Optionally, the positioning hole and the corresponding heating section are coaxially arranged.

[0026] Optionally, the two first lead-out rods are fixed by welding.

[0027] Optionally, the two first lead-out rods are electrically connected through the electrical connector.

[0028] Optionally, the two first lead-out rods are integrally bent and connected.

[0029] Optionally, the two terminals are arranged at an included angle, and a distance between the two terminals gradually increases in a direction away from the tube body.

[0030] Optionally, an insulating wrapper is provided outside the terminal, and an end of the terminal away from the tube body is exposed beyond the insulating wrapper.

[0031] Optionally, the tube body is filled with an electrically insulating and thermally conductive material, and the electrically insulating and thermally conductive material is configured to isolate the two heating elements and to isolate the heating element from a wall of the tube body.

[0032] Optionally, the tube body is an electrically insulating and thermally conductive member.

[0033] In order to achieve the above purpose, the present invention also provides a dry heater, comprising a heater sleeve, a mounting base and the heating tube as described above.

[0034] Optionally, an end of the heater sleeve is closed, and the other end of the heater sleeve is open.

[0035] Optionally, the mounting base is connected to an open end of the heater sleeve and open corresponding to a position of the heater sleeve.

[0036] Optionally, the heating tube is provided in the heater sleeve, and a terminal of the heating tube is provided outside the heater sleeve.

[0037] In order to achieve the above purpose, the present invention also provides a water heater, comprising a tank and the heating tube as described above, and the heating tube is suitable for heating water in the tank.

[0038] In order to achieve the above purpose, the present invention also provides a water heater, comprising the dry heater as described above and a tank. An enclosed end of a heater sleeve extends into the tank, and a mounting base is fixed to an opening of the tank.

[0039] In the heating tube of the technical solution of the present invention, two heating elements are arranged side by side in the tube body. By electrically connecting the two heating elements outside the first end of the tube body, each of the two heating elements has a terminal extending out of the second end at the second end of the tube body for electrical connection with the power supply outside the tube body to realize the normal heating function of the two heating elements in the tube body. In this embodiment, both terminals of the heating element are extended from the same end of the tube body, thereby eliminating the need to fold the tube body in half using hydraulic pressure, simplifying the processing technology, and reducing mechanical damage to the tube body and the heating element. At the same time, it is convenient to control the outer diameter of the tube body, with high processing precision, which greatly reduces the gap between the heating tube and the inner wall of the heater sleeve, ensures that the heat of the heating tube is transferred to the sleeve in time and heat exchanges with water, and ensures the life of the heating tube. In addition, an insulation sleeve is provided outside the first end of the tube body and provided outside the two heating elements to isolate the heating element from the heater sleeve and avoid electric leakage caused by electrical conduction between the heating element and the heater sleeve, improving safety.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly describe the embodiments of the present invention or the technical solutions in the related art, accompanying drawings needed to be used in the description of the embodiments or the related art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts. FIG. 1 is a schematic structural view of a heating tube according to an embodiment of the present invention. FIG. 2 is a partial enlarged view at portion A in FIG. 1. FIG. 3 is a partial enlarged view at portion B in FIG. 1. FIG. 4 is a schematic structural view of match between an insulation sleeve and the tube body when the insulation sleeve is a straight pipe structure according to an embodiment of the present invention. FIG. 5 is a schematic structural view of match between the insulation sleeve and the tube body when the insulation sleeve is a necking pipe structure according to an embodiment of the present invention. FIG. 6 is a schematic structural view of match between the insulation sleeve and the tube body when the insulation sleeve is a box structure according to an embodiment of the present invention. FIG. 7 is a schematic structural view of a terminal at a second end of the tube body according to the present invention. FIG. 8 is a schematic structural view of a heater sleeve and a mounting base according to an embodiment of the present invention. FIG. 9 is a schematic structural view of a water heater according to an embodiment of the present invention.

[0041] Description of reference signs reference signnamereference signname1heating tube142accommodation cavity11tube body15insulated plug12heating element151positioning hole121heating section16electrically insulating and thermally conductive material122first lead-out rod17adhesive part123terminal2heater sleeve1231second lead-out rod3mounting base1232insulating wrapper4tank13electrical connector41opening14insulation sleeve51water inlet pipe141through hole52water outlet pipe

[0042] The realization of the purpose, functional features and advantages of the present invention will be further described in conjunction with the embodiments, with reference to the accompanying drawings.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some rather than all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present invention.

[0044] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship, movement conditions, etc. between the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second",, etc. are only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly comprise at least one of these features. In addition, the meaning of "and / or" in the text comprises three parallel solutions. Taking "A and / or B" as an example, it comprises solution A, or solution B, or a solution that A and B satisfy at the same time. In addition, the technical solutions in the various embodiments can be combined with each other, but it must be based on what a person of ordinary skill in the art can implement. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist, nor is it within the scope of the present invention.

[0046] The heating tube of the existing dry heater needs to be folded in half, hydraulically formed and other processes during the processing. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the folding and hydraulic forming process, external force squeezes the tube of the heating tube and the magnesium oxide powder in the heating tube, which will cause mechanical damage to the resistance wire in the heating tube, and can easily cause premature damage to the resistance wire during use.

[0047] The heating tube of the existing dry heater needs to be integrally folded in half, hydraulic forming and other processes during the processing process. It is processed from a long straight round tube into a long straight oval tube after being folded in half. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the hydraulic forming process, external force squeezes the tube and the magnesium oxide powder in the heating tube, causing mechanical damage to the resistance wire in the heating tube. It is easy to cause the resistance wire to be damaged in advance during use. The existing technology has the problem that the processing technology for the heating tube is complicated and the resistance wire is easy to break. In addition, there is also the problem of leakage caused by electrical conduction between the heating tube and the heater sleeve in the related art.

[0048] Based on this, the present invention proposes a heating tube 1, which aims to eliminate the need to bend the electric heating tube as a whole, simplify the processing technology, and reduce the risk of wire breakage. When the heating tube 1 is used in a heater sleeve 2, the isolation and insulation effect between the heating tube 1 and the heater sleeve 2 can be ensured and electrical conduction can be avoided. The structure of the heating tube 1 will be described below by way of example.

[0049] As shown in FIG. 1 to FIG. 6, in the embodiment of the present invention, the heating tube 1 comprises a tube body 11, two heating elements 12 and an insulation sleeve 14.

[0050] The tube body 11 has a first end and a second end opposite to the first end. The two heating elements 12 are provided side by side in the tube body 11. The two heating elements 12 are electrically connected outside the first end. Each of the two heating elements 12 has a terminal 123 extending out of the second end. The insulation sleeve 14 is provided outside the first end and is sleeved on the parts of the two heating elements 12 extending out of the first end.

[0051] In this embodiment, the tube body 11 plays the role of installing the heating element 12 and conducting the heat of the heating element 12 away. It can be understood that the insulation between the tube body 11 and the heating element 12 prevents leakage problems caused by electrical conduction between the heating element 12 and the tube body 11. At the same time, the tube body 11 can quickly conduct the heat inside to the outside. In an embodiment, the tube body 11 can be a metal tube or a non-metal tube with good thermal conductivity. The tube body 11 itself can be made of insulating material or non-insulating material. When the tube body 11 is made of non-insulating material, the tube body 11 can be isolated and insulated from the heating element 12 by filling the inside of the tube body 11 with insulating material. In an embodiment, the cross-sectional shape of the tube body 11 can be circular, semicircular, square, triangular or other special shapes. In practical applications, the tube body 11 can be configured as a circular tube that is easy to form.

[0052] The two heating elements 12 are arranged side by side in the tube body 11. It can be understood that the two heating elements 12 are arranged in parallel and spaced apart in the tube body 11. The heating element 12 can be a structure that only comprises a resistance wire with high heating efficiency, in which case the heating element 12 is a resistance wire structure as a whole; or the heating element 12 can comprise a resistance wire and other conductive structures, in which case the lead-out rod structure or wire structure can be provided at both ends of the resistance wire.

[0053] The two heating elements 12 are electrically connected outside the first end. It can be understood that the electrical connection position of the two heating elements 12 is outside the tube body 11, which can make the electrical connection operation more convenient and improve the assembly efficiency. The two heating elements 12 are respectively provided with terminals 123 at the second end of the tube body 11. The two terminals 123 are respectively a positive terminal and a negative terminal, used to extend out of the second end of the tube body 11 to be electrically connected to the external power supply, enabling the two heating elements 12 to be energized and generate heat. Therefore, the terminals 123 of the two heating elements 12 both extend out from the same end of the tube body 11, and there is no need to fold the tube body 11 in half or hydraulic pressure, which simplifies the process and reduces the mechanical damage to the tube body 11 and the resistance wire. The specific structure of the terminal 123 can be determined according to the actual situation, in an embodiment, it can be a lead-out rod structure, a wire structure, a conductive sheet structure or other terminal structures, etc., as long as it can ensure that the heating element 12 is electrically connected to an external power supply, its specific structure is not limited here.

[0054] The insulation sleeve 14 is provided outside the first end and is provided outside the two heating elements 12. It can be understood that when the heating tube 1 is used in a dry heater, the heating tube 1 is placed on the heater sleeve 2 for use. Since the two heating elements 12 are electrically connected outside the tube body 11, in order to avoid electric leakage caused by electrical conduction between the heating element 12 and the heater sleeve 2, in this embodiment, the insulation sleeve 14 is provided at the first end of the tube body 11, the insulation sleeve 14 is placed outside the two heating elements 12 to isolate the heating elements 12 and the heater sleeve 2 to improve safety. The outer diameter of the insulation sleeve 14 is smaller than the inner diameter of the heater sleeve 2 to avoid hindering the installation of the heating tube 1 into the heater sleeve 2. It should be noted that when the heating tube 1 is powered on and heated, the temperature inside the heater sleeve 2 is relatively high and will reach a high temperature of 300°C to 400°C. Therefore, the insulation sleeve 14 needs to be non-deformable and invariant under long-term high temperature conditions, and maintains good insulation performance. In an embodiment, the insulation sleeve 14 can be made of high-temperature resistant heat shrinkable sleeves, fiberglass insulation sleeves, ceramics, glass and other materials, or polyimide and chemical substances with similar molecular structures, or polyphenylene sulfide, polyether ketone and other chemical substances with similar molecular structures, or polytetrafluoroethylene and chemical substances with similar molecular structures.

[0055] In practical applications, the inside of the tube body 11 is filled with magnesium oxide powder with good thermal conductivity. The compactness of the magnesium oxide powder is related to the thermal conductivity. In the related art, in order to realize the folding and extrusion of the heating tube 1 as a whole, the magnesium oxide powder filled inside needs to be in a loose state, and the loose magnesium oxide powder has poor heat transfer efficiency, which will cause the internal heating wire to overheat, leading to dry burning and breakage. In this embodiment, there is no need for overall bending the heating tube 1, and there is no need to reduce the compactness of the magnesium oxide powder, which can ensure the compactness of the magnesium oxide powder and improve the thermal conductivity efficiency, thereby preventing the heating wire from dry burning and overheating, and reducing the occurrence of malfunctions.

[0056] In summary, in the heating tube 1 of the technical solution of the present invention, two heating elements 12 are arranged side by side in the tube body 11. By electrically connecting the two heating elements 12 outside the first end of the tube body 11, the two heating elements 12 respectively have terminals 123 extending out of the second end at the second end of the tube body 11 for electrical connection with the power supply outside the tube body 11, realizing normal heating function of the two heating elements 12 in the tube body 11. In this embodiment, two terminals 123 of the heating element 12 are extended out from the same end of the tube body 11, thereby eliminating the need for hydraulic pressure operation to fold the tube body 11, simplifying the processing technology, and reducing mechanical damage to the tube body 11 and the heating element 12. At the same time, it is convenient to control the outer diameter of the tube body 11, and the processing precision is high, which greatly reduces the gap between the heating tube 1 and the inner wall of the heater sleeve 2, ensures that the heat of the heating tube 1 is transferred to the casing in time, and exchanges heat with water, thereby ensuring the life of the heating tube 1. In addition, the insulation sleeve 14 is provided on the outside of the first end of the tube body 11 and provided on the outside of the two heating elements 12 to isolate the heating element 12 from the heater sleeve 2, to avoid electrical leakage caused by electrical conduction between the heating element 12 and the heater sleeve 2, and improve safety.

[0057] In an embodiment of the present invention, as shown in FIG. 2 and FIG. 4 to FIG. 6, the insulation sleeve 14 is provided with an accommodation cavity 142 and an through hole 141 communicated with the accommodation cavity 142. The through hole 141 is opposite to the first end, and the two heating elements 12 extends into the accommodation cavity 142 through the through hole 141 and is electrically connected in the accommodation cavity 142.

[0058] In this embodiment, the insulation sleeve 14 is provided with the through hole 141 for the two heating elements 12 to pass through, so that the heating element 12 can smoothly extend into the accommodation cavity 142 after extending out from the first end of the tube body 11 and be wrapped and isolated by the insulation sleeve 14. This prevents the heating element 12 from being electrically conductive with external conductors such as the heater sleeve 2 and causing leakage problems. In an embodiment, the insulation sleeve 14 can completely or partially wrap the part of the two heating elements 12 located outside the first end.

[0059] The connection structure of the insulation sleeve 14 and the tube body 11 can be determined according to actual conditions.

[0060] As an example, as shown in FIG. 4 and FIG. 5, one end of the insulation sleeve 14 with the through hole 141 is sleeved on the outer wall of the tube body 11, and the insulation sleeve 14 is interference-fitted or bonded with the outer wall of the tube body 11. In this way, it is only necessary to put the insulation sleeve 14 on the tube body 11, which is easy to operate and has high assembly efficiency.

[0061] As an example, as shown in FIG. 6, one end of the insulation sleeve 14 with the through hole 141 is connected to the end of the tube body 11, and the insulation sleeve 14 is fixed to the tube body 11 through an adhesive part 17. In an embodiment, the adhesive part 17 is high-temperature resistant glue. In this way, the peripheral wall of the insulation sleeve 14 can be aligned with the outer peripheral wall of the tube body 11. On the one hand, the overall appearance integrity of the heating tube 1 can be ensured, and on the other hand, the outer peripheral wall of the insulation sleeve 14 does not protrude from the tube body 11, which can make it easier for the heating tube 1 to be inserted into the heater sleeve 2, can reduce the gap between the heating pipe 1 and the heater sleeve 2, and improve the heat transfer efficiency.

[0062] In an embodiment of the present invention, the specific structure of the insulation sleeve 14 can be determined according to actual conditions.

[0063] As an example, as shown in FIG. 4 and FIG. 5, the insulation sleeve 14 has a tube structure. In this embodiment, the insulation sleeve 14 can be a straight tube (as shown in FIG. 4), or one end of the insulation sleeve 14 away from the tube body 11 is tapered (as shown in FIG. 5). The insulation sleeve 14 can be a high temperature resistant heat shrinkable sleeve or a fiberglass insulation sleeve. It can be understood that both ends of the insulation sleeve 14 of the cylindrical structure in this embodiment are open, and the heat generated by the heating element 12 located inside the insulation sleeve 14 can be output outward through the through hole of the insulation sleeve 14, further improving the heating efficiency of the heating tube 1.

[0064] As an example, as shown in FIG. 6, the insulation sleeve 14 has a box structure, and one end of the insulation sleeve 14 away from the tube body 11 is enclosed. It can be understood that the insulation sleeve 14 can fully or partially wrap the heating element 12 extending outside the tube body 11. The insulation sleeve 14 can be made of ceramic beads, glass beads, Teflon beads or other materials.

[0065] When the insulation sleeve 14 fully wraps the heating element 12, as shown in FIG. 6(e) and FIG. 6(f), the insulation sleeve 14 is connected to the first end of the tube body 11 to form a relatively closed cavity. At this time, the wrapping of the heating element 12 outside the tube body 11 (the first lead-out rod 122 and the electrical connector 13) is stronger, further improving the electrical isolation effect. In this manner, the two first lead-out rods 122 need to be electrically connected first or electrically connected through the electrical connector 13 before the insulation sleeve 14 is installed.

[0066] When the insulation sleeve 14 partially wraps the heating element 12, as shown in FIG. 6(g), a hollow hole (not shown) communicated with the accommodation cavity 142 can be provided on the peripheral wall of the insulation sleeve 14. The insulation sleeve 14 is provided with two through holes 141. Each through hole 141 is correspondingly penetrates a heating element 12. The heating tube 1 also comprises an electrical connector 13. The electrical connector 13 can be installed in the accommodation cavity 142 through the hollow hole to electrically connect the two heating elements 12. In this implementation, the insulation sleeve 14 protects the portion of the heating element 12 outside the tube body 11 (the first lead-out rod 122 and the electrical connector 13), and can quickly transmit heat. In actual applications, the two first lead-out rods 122 can extend into the accommodation cavity 142 from the two through holes 141, then the electrical connector 13 is put into the insulation sleeve 14 through the hollow hole and welded with the two first lead-out rods 122, and the insulation sleeve 14 is installed and fixed after welding. In this way, the insulation sleeve 14 is directly fixed and limited by the matching structure of the electrical connector 13 and the first lead-out rod 122, without providing an additional special fixing structure to fix the insulation sleeve 14, further simplifying the assembly process.

[0067] In an embodiment of the present invention, as shown in FIG. 1 to FIG. 3, the heating element 12 comprises a heating section 121, a first lead-out rod 122 and a second lead-out rod 1231. The heating section 121 is provided in the tube body 11, one end of the first lead-out rod 122 is connected to the heating section 121, and the other end extends from the first end. One end of the second lead-out rod 1231 is connected to the heating section 121, and the other end extends from the second end to form the terminal 123. Two first lead-out rods 122 are electrically connected outside the first end, and the insulation sleeve 14 is sleeved outside the two first lead-out rods 122.

[0068] The heating section 121 is a structure with high heating efficiency, such as a resistance wire. The first lead-out rod 122 is provided at one end of each heating section 121, and the two first lead-out rods 122 are electrically connected to achieve the electrical conduction of the two heating sections 121, direct bending of the resistance wire can be avoided and damage to the resistance wire can be reduced, thereby increasing the life of the heating tube 1. The resistance wire is usually made of metal or alloy materials and has a certain degree of elasticity. If the resistance wire is directly bent, the resistance wire will be deformed, and the elasticity of the resistance wire will make it try to return to its original shape, so that the two ends of the resistance wire may come into contact with the inner wall of the tube body 11. By arranging the two resistance wires side by side, it is beneficial to maintain the relative position between the two resistance wires, avoid the two resistance wires from contacting each other, and prevent the resistance wire from contacting the inner wall of the tube body 11.

[0069] In practical applications, the first lead-out rod 122 can be a conductive rod, a wire, a conductive sheet, or other conductive structure. The first lead-out rod 122 and the heating section 121 can be connected by welding, winding or other electrical connection methods. It can be understood that the first lead-out rod 122 has a connection end, and the cross-sectional area of the first lead-out rod 122 gradually decreases from the middle of the first lead-out rod 122 to the connection end, so that the connection end forms a tapered shape, which is advantageous for the spiral-shaped resistance wire to be sleeved on the connection end, increases the contact area between the first lead-out rod 122 and the resistance wire, and ensures the electrical connection between the first lead-out rod 122 and the resistance wire.

[0070] The heating section 121 is provided with a second lead-out rod 1231 at the second end. The second lead rod 1231 extends from the second end of the tube body 11 for electrical connection with an external power source. The connection structure between the second lead-out rod 1231 and the heating section 121 can refer to the connection structure between the first lead-out rod 122 and the heating section 121, and will not be described again here.

[0071] The insulation sleeve 14 is provided on the outside of the two first lead-out rods 122 to ensure that the parts of the two first lead-out rods 122 located outside the tube body 11 can be located in the accommodation cavity 142 of the insulation sleeve 14 to prevent electrical conduction with external conductors such as the heater sleeve 2 from causing leakage problems.

[0072] In an embodiment of the present invention, the electrical connection method of the two first lead-out rods 122 can be determined according to actual conditions.

[0073] In an embodiment of the present invention, as shown in FIG. 4(a), FIG. 5(c) and FIG. 6(e), the two first lead-out rods 122 are welded and fixed. It can be understood that, considering that one end of the two first lead-out rods 122 connected to the heating section 121 is spaced apart, one end of the two first lead-out rods 122 away from the heating section 121 can be bent in opposite directions, so that the two first lead-out rods 122 are brought into contact and then fixed by welding. In an embodiment, resistance welding or argon arc welding can be used.

[0074] In an embodiment of the present invention, as shown in FIG. 4(b), FIG. 5(d), FIG. 6(f) and FIG. 6(g), the heating tube 1 also comprises an electrical connector 13 located outside the tube body 11, The two first lead-out rods 122 are electrically connected through the electrical connector 13. In an embodiment, the electrical connector 13 can be a metal conductive component or a non-metallic conductive component. In practical applications, considering the convenience and reliability of connection, a metal conductive component is selected as the electrical connector 13. Metal usually has a higher strength and hardness, able to withstand certain mechanical stress, ensuring the firmness and stability of the connection. Generally, the electrical connector 13 is made of cast iron. The electrical connector 13 can be connected to the two first lead-out rods 122 by welding, screwing or winding. In practical applications, considering processing convenience and reliability, the two first lead-out rods 122 are welded and fixed to the electrical connector 13. In an embodiment, resistance welding or argon arc welding can be used.

[0075] In an embodiment of the present invention, the two first lead-out rods 122 are integrally bent and connected. In this embodiment, the two first lead-out bars 122 are configured as an integrated structure, so there is no need for an additional process of electrically connecting the two first lead-out rods 122, further simplifying the processing technology. In practical applications, one conductor can be bent to form two first lead-out rods 122, and the ends of the two first lead-out rods 122 away from the bends are connected to the two heating sections 121 respectively.

[0076] It should be noted that in actual applications, the electrical connection method of the two first lead-out rods 122 can not be limited to the above-mentioned embodiments, and can also adopt other embodiments, which are not limited here.

[0077] In an embodiment of the present invention, as shown in FIG. 1, the tube body 11 is filled with an electrically insulating and thermally conductive material 16. The electrically insulating and thermally conductive material 16 isolates the two heating elements 12 and isolates the heating element 12 from the wall of the tube body 11.

[0078] The electrically insulating and thermally conductive material 16 can conduct the heat of the heating element 12 to the wall of the tube body 11, which is beneficial to transmitting the heat of the heating element 12. Furthermore, the electrically insulating and thermally conductive material 16 can isolate the two heating elements 12 to prevent the two heating elements 12 from contacting each other and causing safety risks. At the same time, the electrically insulating and thermally conductive material 16 can isolate the heating element 12 from the inner wall of the tube body 11 to prevent the heating element 12 from contacting the inner wall of the tube body 11 and causing the risk of leakage. Generally, the electrically insulating and thermally conductive material 16 is magnesium oxide powder. The magnesium oxide powder has good insulation properties and thermal conductivity, can effectively isolate the current inside the heating tube, and transfer the heat of the resistance wire to the tube body 11 in time to provide insulation and heat conduction. Powdered magnesium oxide powder can form a stable support structure in the heating tube, so that the heating element 12 of the heating tube 1 can be well fixed and supported. This helps to maintain the relative position between the two heating elements 12 and prevent accidental damage to the heating section 121 due to vibration or displacement.

[0079] Compared with the heating tube 1 of the related art, the heating tube 1 of the embodiment of the present invention simplifies the processing process and does not require folding, hydraulic molding and other processes. The design of the straight tube facilitates the addition of magnesium oxide powder, so that the filling density of the internal magnesium oxide powder is high, and the heat of the resistance wire can be conducted outward in time, reducing the impact of high temperature environment on the resistance wire and ensuring the life of the resistance wire.

[0080] In an embodiment, in order to prevent the two heating sections 121 from contacting each other, an isolation structure such as a partition (not shown in the figure) can be provided in the tube body 11, and the partition is provided between the two heating sections 121. The partition is configured to isolate the two heating sections 121 to avoid contact between the two heating sections 121. The partition is made of insulating material, such as silicone oil. In other embodiments, other support structures can also be used to support the two resistance wires to ensure the relative position between the two resistance wires and thereby ensure safety.

[0081] In an embodiment of the present invention, as shown in FIG. 2 and FIG. 3, the heating tube 1 also comprises insulated plugs 15 respectively provided at the first end and the second end of the tube body 11. The two insulated plugs 15 are sealingly connected to the tube openings of the tube body 11 to form a seal cavity, and both ends of the heating element 12 are fixed to two insulated plugs 15 respectively.

[0082] In actual applications, the tube body 11 is filled with an electrically insulating and thermally conductive material 16. In this embodiment, insulated plugs 15 are provided at both ends of the tube body 11. The insulated plug 15 plays a role in sealing the tube opening, preventing the electrically insulating and thermally conductive material 16 from getting damp, and preventing the electrically insulating and thermally conductive material 16 from leaking out of the tube body 11. Both ends of the heating element 12 are respectively fixed to the insulated plugs 15 to support two heating section 121.

[0083] In an embodiment of the present invention, the insulated plug 15 is provided with two positioning holes 151 spaced apart. The two first lead-out rods 122 respectively pass through the two positioning holes 151 at the first end, and the two terminals 123 respectively pass through the two positioning holes 151 at the second end.

[0084] The two positioning holes 151 at the first end are configured to fix the two first lead-out rods 122, and the two positioning holes 151 at the second end are configured to fix the two second lead-out rods 1231, thereby positioning the two heating sections 121 to avoid displacement of the two heating sections 121 and ensure safety. In this embodiment, the two positioning holes 151 are spaced apart so that the two heating sections 121 can be spaced apart, thereby ensuring the gap between the two heating sections 121 and avoiding potential safety hazards caused by the two heating sections 121 coming into contact with each other.

[0085] In an embodiment of the present invention, the positioning hole 151 and the corresponding heating section 121 are coaxially arranged. In an embodiment, the two positioning holes 151 are arranged in parallel, so that the two heating sections 121 are arranged in parallel and opposite to each other to prevent the two heating sections 121 from contacting each other.

[0086] In an embodiment, there can be an interference fit between the positioning hole 151 and the first lead-out rod 122 and between the positioning hole 151 and the terminal 123 to enhance the sealing of the tube body 11 and prevent the electrically insulating and thermally conductive material 16 from getting wet.

[0087] In this embodiment, the two ends of the tube body 11 are open to facilitate filling of the electrically insulating and thermally conductive material 16. The insulated plugs 15 provided at both ends of the tube body 11 can fix the two ends of the heating element 12, thereby ensuring the relative position of the two heating elements 12 and the tube body 11, preventing the heating element 12 from contacting the inner wall of the tube body 11 and causing leakage. The insulated plug 15 is configured to support the heating section 121.

[0088] In an embodiment of the present invention, as shown in FIG. 7, two terminals 123 are provided at an included angle, and the distance between the two terminals 123 gradually increases in a direction away from the tube body 11.

[0089] The two terminals 123 extend out of the second end of the tube body 11 for electrical connection with an external power source. It can be understood that one of the two terminals 123 is the positive pole and the other is the negative pole. In order to ensure the safety of the wiring, it is necessary to increase the creepage distance between the two terminals 123 as much as possible to prevent short circuit. In this embodiment, by gradually increasing the distance between the two terminals 123 in the direction away from the tube body 11, the distance between the two terminals 123 can be further increased. In an embodiment, the two terminals 123 generally form a "V"-shaped structure.

[0090] As an example, an insulating wrapper 1232 is provided on the outside of the terminal 123, and one end of the terminal 123 away from the tube body 11 is exposed to the insulating wrapper 1232.

[0091] One end of the second lead-out rod 1231 is connected to the heating section 121, and the other end extends out of the second end to form a terminal 123 for electrical connection with an external power source. In order to prevent short circuit, an insulating wrapper 1232 is provided on each second lead-out rod 1231. The end of the second lead-out rod 1231 away from the tube body 11 is exposed to the insulating wrapper 1232 to enable smooth connection with the external power supply.

[0092] In an embodiment, the insulating wrapper 1232 can be a heat-shrinkable sleeve structure wrapped around the outer wall of the second lead-out rod 1231.

[0093] In some embodiments, an insulating spacer can be added to the outer end of the insulated plug 15 at the second end of the tube body 11 to further ensure the insulation effect of the two second lead-out rods 1231. The insulating spacer can be bonded and fixed with the insulated plug 15, and the insulating spacer can be made of ceramic, glass, or polytetrafluoroethylene.

[0094] The heating tube of the existing dry heater needs to be integrally folded in half, hydraulic forming and other processes during the processing process. It is processed from a long straight round tube into a long straight oval tube body after being folded in half. Since a heating wire is inserted through the heating tube and the heating tube is filled with magnesium oxide powder, during the hydraulic forming process, external force squeezes the tube and the magnesium oxide powder in the heating tube, causing mechanical damage to the resistance wire in the heating tube. It is easy to cause the resistance wire to be damaged in advance during use. The existing technology has the problem that the heating tube has complicated processing technology and the resistance wire is easy to break.

[0095] Based on this, the present invention proposes a heating tube 1, which aims to eliminate the need to bend the electric heating tube as a whole, simplify the processing technology, and reduce the risk of wire breakage. The structure of the heating tube 1 will be described below by way of example.

[0096] As shown in FIG. 1 to FIG. 6, in the embodiment of the present invention, the heating tube 1 comprises a tube body 11 and a heating element 12.

[0097] The tube body 11 has a first end and a second end opposite to the first end. The heating element 12 comprises two heating sections 121 arranged side by side in the tube body 11. The two heating sections 121 are electrically connected at the first end and are respectively provided with terminals 123 at the second end. Both terminals 123 extend out of the second end

[0098] In this embodiment, the tube body 11 is configured to install the heating element 12 and conduct the heat of the heating element 12 away. It can be understood that the insulation between the tube body 11 and the heating element 12 prevents leakage problems caused by electrical conduction between the heating element 12 and the tube body 11. The tube body 11 can quickly conduct the heat inside to the outside. In an embodiment, the tube body 11 can be a metal tube or a non-metal tube with good thermal conductivity. The tube body 11 itself can be made of insulating material or non-insulating material. When the tube body 11 is made of non-insulating material, the tube body 11 can be isolated and insulated from the heating element 12 by filling the inside of the tube body 11 with insulating material. In an embodiment, the cross-sectional shape of the tube body 11 can be circular, semicircular, square, triangular or other special shapes. In practical applications, the tube body 11 can be configured as a circular tube that is easy to form.

[0099] The heating element 12 comprises two heating sections 121 arranged side by side. It can be understood that the two heating sections 121 are arranged at intervals. The heating section 121 can be a resistance wire with high heating efficiency. In practical applications, the heating element 12 can only comprise the heating section 121, or comprise the heating section 121, other conductive structures, and the like. When the heating element 12 only comprises the heating section 121, the entire heating element 12 can be a resistance wire structure. When the heating element 12 comprises the heating section 121 and other conductive structures, lead-out rod structures or wire structures can be respectively provided at both ends of the resistance wire.

[0100] The two heating sections 121 are electrically connected at the first end of the tube body 11. It can be understood that the electrical connection position of the two heating sections 121 can be located outside the first end of the tube body 11, or can be located inside the first end of the tube body 11. The two heating sections 121 are respectively provided with terminals 123 at the second end of the tube body 11. The two terminals 123 are a positive terminal and a negative terminal, used to extend out of the second end of the tube body 11 for electrically connection with the external power supply, realizing energization and heating of the two heating sections 121. It can be seen from this that the terminals 123 of the two heating sections 121 protrude from the same end of the tube body 11, and there is no need to fold the tube body 11 in half using hydraulic pressure, which simplifies the process and reduces mechanical damage to the tube body 11 and the resistance wire.

[0101] The specific structure of the terminal 123 can be determined according to the actual situation, for example, it can be a lead-out rod structure, a wire structure, a conductive sheet structure or other terminal structures, as long as the heating section 121 inside the tube body 11 can be electrically connected to an external power supply. Its specific structure is not limited here.

[0102] It should be noted that in actual applications, the inside of the tube body 11 is filled with magnesium oxide powder with good thermal conductivity. The compactness of the magnesium oxide powder is related to the thermal conductivity. In the related art, in order to realize the folding and extrusion of the heating tube 1 as a whole, the magnesium oxide powder filled inside needs to be in a loose state, and the heat transfer efficiency of loose magnesium oxide powder is poor, which will cause the internal heating wire to overheat and cause dry burning. In this embodiment, there is no need to bend the heating tube 1 as a whole, and there is no need to reduce the compactness of the magnesium oxide powder. This can ensure the compactness of the magnesium oxide powder and improve the thermal conductivity, thereby preventing the heating wire from dry-burning and overheating, and reducing the occurrence of malfunctions.

[0103] In the heating tube 1 of the technical solution of the present invention, two heating sections 121 are arranged side by side in the tube body 11. By electrically connecting the two heating sections 121 at the first end of the tube body 11, the two heating sections 121 are provided with terminals 123 at the second end of the tube body 11 and both terminals 123 extend out of the same end for electrically connection with the power supply outside the tube body 11, thereby realizing the normal heating function of the two heating sections 121 in the tube body 11. In this embodiment, both terminals 123 of the heating element 12 are extended from the same end of the tube body 11, thereby eliminating the need for hydraulic pressure operation to fold the tube body 11, simplifying the processing technology, and reducing mechanical damage to the tube body 11 and heating section 121; at the same time, it is convenient to control the outer diameter of the tube body 11, with high processing precision, greatly reducing the gap between the heating tube 1 and the inner wall of the heater sleeve 2, ensuring that the heat of the heating tube 1 is transferred to the sleeve in time for heat exchange with water to ensure the service life of the heating tube 1.

[0104] In an embodiment of the present invention, as shown in FIG. 2, FIG. 4 and FIG. 5, each heating section 121 is provided with the first lead-out rod 122 corresponding to the first end, and the two first lead-out rods 122 at least partially extend out of the first end and are electrically connected outside the first end.

[0105] The heating section 121 is a structure with high heating efficiency, such as a resistance wire. By providing the first lead-out rod 122 at one end of each heating section 121, and by using the two first lead-out rods 122 to electrically connect the two heating sections 121, it is possible to avoid direct bending of the resistance wire and reduce damage to the resistance wire, thereby increasing the life of the heating tube 1. The resistance wire is usually made of metal or alloy materials and has a certain degree of elasticity. If the resistance wire is directly bent, the resistance wire will deform. The elasticity of the resistance wire will make it try to return to its original shape, so that both ends of the resistance wire may contact the inner wall of the tube body 11. By arranging the two resistance wires side by side, it is beneficial to maintain the relative position between the two resistance wires, prevent the two resistance wires from contacting each other, and prevent the resistance wire from contacting the inner wall of the tube body 11.

[0106] In addition, the two first lead-out rods 122 at least partially extend out of the first end and are electrically connected outside the first end. Compared with the method in which the resistance wire is extended from the tube body 11 for electrically connection, it is possible to prevent external temperature of the tube body 11 from overheating.

[0107] In practical applications, the first lead-out rod 122 can be a conductive rod, a wire, a conductive sheet, or other conductive structure. The first lead-out rod 122 and the heating section 121 can be connected by welding, winding or other electrical connection methods. It can be understood that the first lead-out rod 122 has a connection end, and the cross-sectional area of the first lead-out rod 122 gradually decreases from the middle of the first lead-out rod 122 to the connection end, so that the connection end forms a tapered shape, which is advantageous for the spiral-shaped resistance wire to be sleeved on the connection end, thereby increasing the contact area between the first lead-out rod 122 and the resistance wire, and ensuring the electrical connection between the first lead-out rod 122 and the resistance wire.

[0108] In an embodiment of the present invention, the electrical connection method of the two first lead-out rods 122 can be determined according to actual conditions.

[0109] In an embodiment of the present invention, as shown in FIG. 4, two first lead rods 122 are welded and fixed. It can be understood that, considering that two ends of the two first lead-out rods 122 connected to the heating section 121 are spaced apart, two end of the two first lead-out rods 122 away from the heating section 121 can be bent in opposite directions, so that the two first lead-out rods 122 are brought into contact and then fixed by welding. In an embodiment, resistance welding or argon arc welding can be used.

[0110] In an embodiment of the present invention, as shown in FIG. 5, the heating tube 1 further comprises an electrical connector 13 provided outside the tube body 11, and the two first lead-out rods 122 are electrically connected through the electrical connector 13. In an embodiment, the electrical connector 13 can be a metal conductive component or a non-metallic conductive component. In practical applications, considering the convenience and reliability of connection, the metal conductive component is selected as the electrical connector 13. Metal usually has a higher strength and hardness, able to withstand certain mechanical stress, ensuring the firmness and stability of the connection. Generally, the electrical connector 13 is made of cast iron. The electrical connector 13 can be connected to the two first lead-out rods 122 by welding, screwing or winding. In practical applications, considering processing convenience and reliability, the two first lead-out rods 122 are welded and fixed to the electrical connector 13. In an embodiment, resistance welding or argon arc welding can be used.

[0111] In an embodiment of the present invention, the two first lead-out rods 122 are integrally bent and connected. In this embodiment, the two first lead-out rods 122 are provided as an integrated structure, so there is no need for an additional process of electrically connecting the two first lead-out bars 122, further simplifying the processing technology. In practical applications, one conductor can be bent to form two first lead-out rods 122, and ends of the two first lead-out bars 122 away from the bends are connected to the two heating sections 121 respectively.

[0112] It should be noted that in actual applications, the electrical connection method of the two first lead-out rods 122 may not be limited to the above-mentioned embodiments, and may also adopt other embodiments, which are not limited here.

[0113] In an embodiment of the present invention, the heating element 12 is a resistance wire, and the resistance wire is bent to form two heating sections 121.

[0114] In the related art, the resistance wire is inserted into the inside of the tube body 11 and then the tube body 11 is bent. In contrast, the resistance wire is directly bent, which has low processing difficulty, is easy to operate, and has small mechanical damage to the resistance wire.

[0115] In an embodiment of the present invention, as shown in FIG. 2, FIG. 4, FIG. 5 and FIG. 6, the heating tube 1 also comprises an insulation sleeve 14 provided at the first end. The insulation sleeve 14 is sleeved outside the two first lead-out rods 122.

[0116] When the heating tube 1 is used in a dry heater, the heating tube 1 is placed in the heater sleeve 2 for use, and since the two first lead-out rods 122 are electrically connected outside the tube body 11, in order to avoid electric leakage caused by the electrical connection between the first lead-out rod 122 and the heater sleeve 2, in this embodiment, an insulation sleeve 14 is provided at the first end of the tube body 11, and the insulation sleeve 14 is sleeved outside the two first lead-out rods 122, to isolate the first lead-out rod 122 and the heater sleeve 2, improving safety. The outer diameter of the insulation sleeve 14 is smaller than the inner diameter of the heater sleeve 2 to avoid hindering the installation of the heating tube 1 into the heater sleeve 2.

[0117] It should be noted that when the heating tube 1 is powered on and heated, the temperature inside the heater sleeve 2 is relatively high and will reach a high temperature of 300°C to 400°C, so the insulation sleeve 14 needs to meet the requirements of nondeformation and invariance under long-term high temperature conditions, maintain good insulation performance. In an embodiment, the insulation sleeve 14 can be made of high-temperature resistant heat shrinkable sleeves, fiberglass insulation sleeves, ceramics, glass and other materials, or polyimide and chemical substances with similar molecular structures, or polyphenylene sulfide, polyether ketone and other chemical substances with similar molecular structures, or polytetrafluoroethylene and chemical substances with similar molecular structures.

[0118] In an embodiment of the present invention, the specific structure of the insulation sleeve 14 can be determined according to actual conditions.

[0119] As an example, as shown in (a) in FIG. 4, (c) in FIG. 5, (b) in FIG. 4, and (d) in FIG. 5, the insulation sleeve 14 has a cylindrical structure. In this embodiment, the insulation sleeve 14 can be directly provided on the outer wall of the first end of the tube body 11, and the two can be fixed by bonding or interference. In this embodiment, the insulation sleeve 14 can have a straight-cylinder structure or a necking structure, and the insulation sleeve 14 can be a high-temperature-resistant heat shrinkable sleeve or a fiberglass insulation sleeve. It can be understood that both ends of the insulation sleeve 14 of the cylindrical structure in this embodiment are open, and the heat generated by the first lead-out rod 122 and the electrical connector 13 located inside the insulation sleeve 14 can be output outward through the through hole of the insulation sleeve 14, thereby further improving the heating efficiency of the heating tube 1.

[0120] As an example, as shown in (e), (g) and (f) in FIG. 6, the insulation sleeve 14 has a box structure. It can be understood that the insulation sleeve 14 is provided with a receiving cavity for accommodating the first lead-out rod 122 and the electrical connector 13. The insulation sleeve 14 of the box structure can fully or partially wrap the first lead-out rod 122 and the electrical connector 13. The insulation sleeve 14 can be made of materials such as ceramic beads, glass beads or Teflon beads.

[0121] As shown in (e) and (f) in FIG. 6, when the insulation sleeve 14 fully wraps the first lead-out rod 122 and the electrical connector 13, the insulation sleeve 14 is connected to the first end of the tube body 11 to form a relatively closed cavity. At this time, the first lead-out rod 122 and the electrical connector 13 are more tightly wrapped, further improving the electrical isolation effect. In this method, the two first lead-out rods 122 need to be electrically connected first or electrically connected through the electrical connector 13 before the insulation sleeve 14 is installed.

[0122] As shown in (g) of FIG. 6, when the insulation sleeve 14 partially wraps the first lead-out rod 122 and the electrical connector 13, an through hole can be provided on the outer peripheral wall of the insulation sleeve 14 to protect the first lead-out rod 122 and the electrical connector 13 while enabling rapid heat transfer. In addition, in actual applications, one end of the insulation sleeve 14 can be connected to the first end of the tube body 11 so that the two first lead-out rods 122 extend into the insulation sleeve 14, and then the electrical connector 13 can be put in the insulation sleeve 14 through the through hole for welding operation. In this embodiment, the insulation sleeve 14 can be bonded and fixed with the first end of the tube body 11. Alternatively, in some embodiments, two installation holes can be provided at one end of the insulation sleeve 14 to pass through the two first lead-out rods 122, then the electrical connector 13 is placed into the insulation sleeve 14 from the through hole and welded with the two first lead-out rods 122, and the insulation sleeve 14 is installed and fixed after welding. In this method, the insulation sleeve 14 is directly fixed and limited by the matching structure of the electrical connector 13 and the first lead-out rod 122 without the need for additional special fixing structures to fix the insulation sleeve 14, which further simplifies the assembly process.

[0123] In an embodiment of the present invention, as shown in FIG. 1, the tube body 11 is filled with an electrically insulating and thermally conductive material 16. The electrically insulating and thermally conductive material 16 isolates the two heating sections 121 and isolates the heating element 12 from the wall of the tube body 11.

[0124] The electrically insulating and thermally conductive material 16 can conduct the heat of the heating section 121 to the wall of the tube body 11, which is conducive to transferring the heat of the heating section 121. Furthermore, the electrically insulating and thermally conductive material 16 can isolate the two heating sections 121 to avoid potential safety hazards caused by the two heating sections 121 contacting each other.. At the same time, the electrically insulating and thermally conductive material 16 can isolate the heating element 12 from the inner wall of the tube body 11 to prevent the heating element 12 from contacting the inner wall of the tube body 11 and causing the risk of leakage. Generally, the electrically insulating and thermally conductive material 16 is magnesium oxide powder. The magnesium oxide powder has good insulation properties and thermal conductivity, can effectively isolate the current inside the heating tube, and transfer the heat of the resistance wire to the tube body 11 in time to provide insulation and heat conduction. Powdered magnesium oxide powder can form a stable support structure in the heating tube, so that the heating section 121 of the heating tube 1 is well fixed and supported. This helps to maintain the relative position between the two heating sections 121 and prevent accidental damage to the heating section 121 due to vibration or displacement.

[0125] Compared with the heating tube 1 of the related art, the heating tube 1 of the embodiment of the present invention simplifies the processing process and does not require folding, hydraulic molding and other processes. The design of the straight tube facilitates the addition of magnesium oxide powder, so that the filling density of the internal magnesium oxide powder is high, and the heat of the resistance wire can be conducted outward in time, reducing the impact of high temperature environment on the resistance wire and ensuring the life of the resistance wire.

[0126] In an embodiment, in order to prevent the two heating sections 121 from contacting each other, an isolation structure such as a partition (not shown in the figure) can be provided in the tube body 11, and the partition is provided between the two heating sections 121. The partition is configured to isolate the two heating sections 121 to avoid contact between the two heating sections 121. The partition is made of insulating material, such as silicone oil. In other embodiments, other support structures can also be used to support the two resistance wires to ensure the relative position between the two resistance wires and thereby ensure safety.

[0127] In order to prevent the two heating sections 121 from contacting each other, the length of the heating section 121 can be limited, for example, the length of the heating section 121 is less than 500 millimeters, thereby reducing the risk of displacement of the two heating sections 121 due to vibration. If the length of the heating section 121 is too long, the heating section 121 will easily swing when subjected to vibration, increasing uncertainty.

[0128] In an embodiment of the present invention, as shown in FIG. 2 and FIG. 3, the heating tube 1 also comprises insulated plugs 15 respectively provided at the first end and the second end of the tube body 11. The two insulated plugs 15 are sealingly connected to the tube openings of the tube body 11 to form a seal cavity, and both ends of the heating element 12 are fixed to two insulated plugs 15 respectively.

[0129] In actual applications, the tube body 11 is filled with an electrically insulating and thermally conductive material 16. In this embodiment, insulated plugs 15 are provided at both ends of the tube body 11. The insulated plugs 15 is used to seal the tube opening to prevent the electrically insulating and thermally conductive material 16 from getting damp while preventing the electrically insulating and thermally conductive material 16 from leaking out of the tube body 11. Both ends of the heating element 12 are respectively fixed to the insulated plugs 15 to support the two heating sections 121.

[0130] In an embodiment of the present invention, the insulated plug 15 is provided with two positioning holes 151 spaced apart, and the two first lead-out rods 122 respectively pass through the two positioning holes 151 at the first end, and the two terminals 123 respectively pass through the two positioning holes 151 located at the second end.

[0131] The two positioning holes 151 at the first end are used to fix the two first lead-out rods 122, and the two positioning holes 151 at the second end are used to fix the two terminals 123, thereby positioning the two heating sections 121, to avoid displacement of the two heating sections 121 and ensure safety. In this embodiment, the two positioning holes 151 are spaced apart so that the two heating sections 121 can be spaced apart, thereby ensuring the gap between the two heating sections 121 and preventing the two heating sections 121 from contacting each other and causing safety hazards.

[0132] In an embodiment of the present invention, the positioning hole 151 and the corresponding heating section 121 are coaxially arranged. In an embodiment, the two positioning holes 151 are arranged in parallel, so that the two heating sections 121 are arranged in parallel and opposite to each other to prevent the two heating sections 121 from contacting each other.

[0133] In an embodiment, there can be an interference fit between the positioning hole 151 and the first lead-out rod 122 and between the positioning hole 151 and the terminal 123 to enhance the sealing of the tube body 11 and prevent the electrically insulating and thermally conductive material 16 from getting wet.

[0134] In this embodiment, the two ends of the tube body 11 are open to facilitate filling of the electrically insulating and thermally conductive material 16. The insulated plugs 15 provided at both ends of the tube body 11 can fix the two ends of the heating element 12, thereby ensuring the relative position of the two heating elements 12 and the tube body 11, preventing the heating element 12 from contacting the inner wall of the tube body 11 and causing leakage. The insulated plug 15 is used to support the heating section 121.

[0135] In an embodiment of the present invention, as shown in FIG. 7, two terminals 123 are arranged at an included angle, and the distance between the two terminals 123 gradually increases in a direction away from the tube body 11.

[0136] Two terminals 123 extend out of the second end of the tube body 11 for electrical connection with an external power source. It can be understood that one of the two terminals 123 is the positive pole and the other is the negative pole. In order to ensure the safety of the wiring, it is necessary to increase the creepage distance between the two terminals 123 as much as possible to prevent short circuit. In this embodiment, by gradually increasing the distance between the two terminals 123 in a direction away from the tube body 11, the distance between the two terminals 123 can be further increased. In an embodiment, the two terminals 123 generally form a "V"-shaped structure.

[0137] As an example, the terminal 123 comprises a second lead-out rod 1231 and an insulating wrapper 1232. One end of the second lead-out rod 1231 is connected to the corresponding heating section 121, and the other end extends out of the second end of the tube body 11. The insulating wrapper 1232 is connected to the second end and wraps around the outside of the second lead-out rod 1231. One end of the second lead-out rod 1231 away from the tube body 11 is exposed to the insulating wrapper 1232.

[0138] In this embodiment, the connection structure between the second lead-out rod 1231 and the heating section 121 and the connection structure between the second lead-out rod 1231 and the insulated plug 15 can refer to the aforementioned connection method of the first lead-out rod 122 and will not be described again here. One end of the second lead-out rod 1231 is connected to the heating section 121, and the other end extends out of the second end of the tube body 11 for electrical connection with an external power source. In order to prevent short circuit, the insulating wrapper 1232 is provided on each second lead-out rod 1231. At the same time, the end of the second lead-out rod 1231 away from the tube body 11 is exposed to the insulating wrapper 1232 to enable smooth connection with the external power supply.

[0139] In an embodiment, the insulating wrapper 1232 can be a heat-shrinkable sleeve structure wrapped around the outer wall of the second lead-out rod 1231.

[0140] In some embodiments, an insulating spacer can be added to the outer end of the insulated plug 15 at the second end of the tube body 11 to further ensure the insulation effect of the two second lead-out rods 1231. The insulating spacer can be bonded and fixed with the insulated plug 15, and the insulating spacer can be made of ceramic, glass, or polytetrafluoroethylene.

[0141] The present invention also proposes a dry heater, as shown in FIG. 1, FIG. 8 and FIG. 9, the dry heater comprises a heater sleeve 2, a mounting base 3 and a heating tube 1. The specific structure of the heating tube 1 refers to the above embodiment. Since this dry heater adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here. One end of the heater sleeve 2 is closed and the other end of the heater sleeve 2 is open. The mounting base 3 is connected to the open end of the heater sleeve 2 and is open corresponding to the position of the heater sleeve 2. The heating tube 1 is provided in the heater sleeve 2, and the terminal 123 of the heating tube 1 is provided outside the heater sleeve 2.

[0142] In actual applications, the enclosed end of the heater sleeve 2 extends into the tank 4 of the water heater, and the mounting seat 3 is installed at the opening 41 of the tank 4, so that the heater sleeve 2 can be fixed inside the tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the tank 4 is heated through the heater sleeve 2. If the dry heater fails, there is no need to disassemble the mounting base 3 or drain the water in the tank 4. Just remove the heating tube 1 from the heater sleeve 2. The disassembly and installation are very simple.

[0143] In this embodiment, the tube body 11 of the heating tube 1 does not require processes such as folding in half or hydraulic pressure, resulting in higher machining precision for the tube body 11. The outer diameter of the heating tube can be processed by a multiroller tube shrinking machine and can be controlled within the range of ±0.1 mm. This greatly reduces the gap between the heating tube 1 and the inner wall of the heater sleeve 2, ensuring that the heat of the heating tube 1 is transferred to the heater sleeve 2 in time for heat exchange with water, thus ensuring the life of the heating tube 1. At the same time, the insulation sleeve 14 provided in the heating tube 1 can isolate the heating element 12 and the heater sleeve 2, prevent the heating element 12 from being electrically conductive with the heater sleeve 2, and improve safety.

[0144] The present invention also proposes a water heater. The water heater comprises an tank 4 and a heating tube 1. The specific structure of the heating tube 1 refers to the above-mentioned embodiments. Since this water heater adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solution of the above-mentioned embodiments, which will not be repeated here. The heating tube 1 is suitable for heating the water in the tank 4. In this embodiment, the heating tube 1 can directly heat the water in the tank 4, or can be installed in the tank 4 through other installation components for heating.

[0145] The present invention also proposes a water heater, as shown in FIG. 9, the water heater comprises an tank 4 and a dry heater. The specific structure of the dry heater refers to the above embodiments. Since this water heater adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated again. The enclosed end of the heater sleeve 2 extends into the tank 4, and the mounting base 3 is fixed to the opening 41 of the tank 4.

[0146] The inner pot 4 has a water inlet pipe 51 and a water outlet pipe 52. The water inlet pipe 51 is used to feed cold water into the tank 4, and the water outlet pipe 52 is used to discharge hot water from the tank 4. The tank 4 is provided with the opening 41. By fixing the mounting base 3 to the opening 41, the heater sleeve 2 is fixed inside the tank 4. The heating tube 1 is installed in the heater sleeve 2, and the water in the tank 4 is heated through the heater sleeve 2. When the heating tube 1 fails, there is no need to disassemble the mounting base 3 or drain the water in the tank 4. The heating tube 1 can be directly removed. The disassembly and installation are very simple.

[0147] The above are only some embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the technical concept of the present invention, equivalent structural transformations made using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are comprised in the scope of the present invention.

Claims

1. A heating tube, <b>characterized by comprising: a tube body provided with a first end and a second end opposite to the first end; two heating elements provided side by side in the tube body, wherein the two heating elements are electrically connected outside the first end, and wherein each of the two heating elements has a terminal extending out of the second end; and an insulation sleeve provided outside the first end and sleeved at a portion of the two heating elements extending out of the first end.

2. The heating tube according to claim 1, wherein the insulation sleeve is provided with an accommodation cavity and an through hole communicated with the accommodation cavity, wherein the through hole is opposite to the first end, and wherein the two heating elements extend into the accommodation cavity through the through hole and are electrically connected in the accommodation cavity.

3. The heating tube according to claim 2, wherein an end of the insulation sleeve with the through hole is sleeved on an outer wall of the tube body, and wherein the insulation sleeve is interference-fitted or bonded with the outer wall of the tube body.

4. The heating tube according to claim 2 or 3, wherein an end of the insulation sleeve with the through hole is connected to an end of the tube body, and wherein the insulation sleeve is fixed to the tube body through an adhesive part.

5. The heating tube according to any one of claims 2 to 4, wherein the insulation sleeve has a straight pipe structure; or an end of the insulation sleeve away from the tube body is tapered; or the insulation sleeve has a box structure, and an end of the insulation sleeve away from the tube body is enclosed.

6. The heating tube according to any one of claims 2 to 5, wherein a peripheral wall of the insulation sleeve is provided with a hollow hole communicated with the accommodation cavity, the insulation sleeve being provided with two through holes, each of the through holes being provided with the heating element in a passing through manner correspondingly; and the heating tube further comprises an electrical connector, the electrical connector being installed in the accommodation cavity through the hollow hole to electrically connect the two heating elements.

7. The heating tube according to any one of claims 1 to 5, wherein the heating elements is a resistance wire, and wherein the resistance wire is bent to form two heating sections.

8. The heating tube according to any one of claims 1 to 7, wherein the insulation sleeve is a ceramic piece, a glass piece or a Teflon piece.

9. The heating tube according to any one of claims 1 to 7, wherein the heating elements comprises: the heating section provided in the tube body; a first lead-out rod, wherein the first lead-out rod has an end connected to the heating section and the other end extending out of the first end; and a second lead-out rod, wherein the second lead-out rod has an end connected to the heating section and the other end extending out the second end to form the terminal; wherein two first lead-out rods are electrically connected outside the first end, and wherein the insulation sleeve is sleeved outside the two first lead-out rods.

10. The heating tube according to claim 9, further comprising: insulated plugs respectively provided at the first end and the second end of the tube body, wherein the two insulated plugs are sealingly connected to tube openings of the tube body to form a seal cavity, and wherein two ends of the heating element are respectively fixed to the two insulated plugs.

11. The heating tube according to claim 10, wherein the insulated plug is provided with two positioning holes spaced apart, wherein the two first lead-out rods respectively pass through two positioning holes located at the first end, wherein the two terminals respectively pass through two positioning holes located at the second end, and wherein the positioning hole and the corresponding heating section are coaxially arranged.

12. The heating tube according to any one of claims 9 to 11, wherein the two first lead-out rods are fixed by welding; or the two first lead-out rods are electrically connected through the electrical connector; or the two first lead-out rods are integrally bent and connected.

13. The heating tube according to any one of claims 1 to 12, wherein the two terminals are arranged at an included angle, and wherein a distance between the two terminals gradually increases in a direction away from the tube body; and an insulating wrapper is provided outside the terminal, and an end of the terminal away from the tube body is exposed beyond the insulating wrapper.

14. The heating tube according to any one of claims 1 to 13, wherein the tube body is filled with an electrically insulating and thermally conductive material (16), and wherein the electrically insulating and thermally conductive material (16) is configured to isolate the two heating elements and to isolate the heating element (12) from a wall of the tube body (11); and / or the tube body (11) is an electrically insulating and thermally conductive member.

15. A dry heater, <b>characterized by comprising: a heater sleeve with an end closed, and the other end open; a mounting base connected to the open end of the heater sleeve and being open corresponding to a position of the heater sleeve; and a heating tube according to any one of claims 1 to 14, wherein the heating tube is provided in the heater sleeve, and wherein a terminal of the heating tube is provided outside the heater sleeve.

16. A water heater, <b>characterized by comprising: a tank and a heating tube according to any one of claims 1 to 14, wherein the heating tube is suitable for heating water in the tank; or the water heater comprising: a dry heater according to claim 15 and a tank, wherein an enclosed end of a heater sleeve extends into the tank, and wherein a mounting base is fixed to an opening of the tank.

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