Electric heater with porous sintering

Abstract

The utility model relates to the technical field of electric heaters, in particular to an electric heater with porous sintering. Comprising a pressure vessel tube; the electric heating tube is axially arranged in the pressure vessel tube; comprising an electric heating outer tube, magnesium oxide powder, an electric heating wire and a guide rod, the electric heating wire of a spiral structure is axially inserted into the electric heating outer pipe, the guide rods are arranged at the two ends of the electric heating wire, and the magnesium oxide powder is filled in gaps between the electric heating outer pipe and the electric heating wire and between the electric heating outer pipe and the guide rods. The porous medium is metal metallurgy powder or metal ball particles; and the filler is filled between the electric heating tube and the pressure vessel tube. The pressure container tube, the electric heating tube and the porous medium are made of high-pressure forged contracted tubes. The electric heater is small in size, high in heat transfer coefficient, heavy in whole electric heating tube weight, large in heat capacity in the heating process, high in temperature impact resistance and particularly suitable for high-pressure, low-flow and high-temperature heating occasions.

Description

Technical Field

[0001] The utility model relates to the technical field of electric heaters, in particular to an electric heater with porous sintering. Background Art

[0002] Generally, for high-pressure, low-flow heating occasions, if the traditional circulation electric heater structure is still used, due to the low flow rate, slow flow rate and small heat transfer coefficient, in order to avoid overheating of the electric heating tube, the load has to be reduced. This results in a large equipment size and high cost. Therefore, high-pressure, low-flow heating occasions expose the defects of the use of traditional circulation heaters. Utility Model Content

[0003] The utility model aims to provide an electric heater with porous sintering, which has a small volume, a high heat transfer coefficient, a heavy weight of the entire electric heating tube, a large heat capacity during the heating process, and a strong ability to resist temperature shock, and is particularly suitable for high pressure, low flow and high temperature heating occasions.

[0004] In order to solve the above technical problems, the utility model provides an electric heater with porous sintering, comprising:

[0005] Pressure vessel pipes;

[0006] The electric heating tube is axially arranged in the pressure vessel tube; it comprises an electric heating outer tube, magnesium oxide powder, an electric heating wire and a lead rod; the electric heating wire in a spiral structure is axially inserted in the electric heating outer tube, the lead rods are arranged at both ends of the electric heating wire, and the gap between the electric heating outer tube and the electric heating wire and the lead rod is filled with the magnesium oxide powder;

[0007] The porous medium is metal metallurgical powder or metal ball particles, and is filled between the electric heating tube and the pressure container tube.

[0008] Preferably, the pressure vessel tube, the electric heating tube and the porous medium are made of high-pressure forged shrink tubes.

[0009] Preferably, the porous medium has a high degree of filling (filled by vibration), and the pressure vessel tube, the electric heating tube and the porous medium are made by high-temperature sintering at 1050°C.

[0010] Preferably, the porous medium is filled in a certain proportion according to a certain mesh size to improve the heat transfer performance of the porous medium.

[0011] Preferably, the electric heating tube, the porous medium and the pressure vessel tube are in close contact to ensure a heat transfer channel between the electric heating tube and the porous medium.

[0012] Preferably, the heating wire adopts an equal load design, that is, the power density of the heating wire is high at the fluid inlet end, and the power density of the heating wire is low at the fluid outlet end.

[0013] Preferably, a temperature sensor is further included, and the electric heating tube is in close contact with the temperature sensor.

[0014] Preferably, the temperature sensor is closely attached to the outer electric heating tube or inserted into the center of the magnesium oxide powder to ensure the accuracy of the temperature sensor in measuring the temperature of the electric heating tube and to accurately alarm.

[0015] Preferably, the outer wall of the electric heating outer tube is coated with a high-temperature resistant high-radiation coefficient coating to reduce the temperature of the outer wall of the electric heating outer tube.

[0016] Preferably, the end of the electric heating tube is connected to the lead rod by a two-phase or three-phase power connector, and the junction box of the two-phase or three-phase power connector is designed with an explosion-proof structure.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] 1. The electric heater composed of the electric heating tube, porous medium and pressure vessel tube designed by the utility model is particularly suitable for high pressure, low flow and high temperature heating occasions.

[0019] 2. The electric heater designed by the utility model has a heavy weight, a large heat capacity during heating, and a strong ability to resist temperature shock, because the electric heating tube, porous medium and pressure vessel tube are shrunk together by high-pressure forging. The electric heater is particularly suitable for heating occasions with a temperature of about 1000°C.

[0020] 3. If the electric heating tube designed by the utility model is used in heating occasions of the heated fluid with heat radiation absorption, the outer shell of the electric heating tube will be coated with a high-temperature resistant high-radiation coefficient coating, which can reduce the temperature of the outer shell of the electric heating tube.

[0021] 4. The gap between the electric heating tube and the pressure vessel tube designed in the utility model is filled with porous media. After vibration filling, the electric heating tube is sintered at a high temperature of 1050°C, which further increases the heat transfer channel of the metal metallurgical powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The utility model is a three-dimensional diagram of an electric heater with porous sintering.

[0023] Figure 2 It is a cross-sectional view of an electric heater with porous sintering according to the utility model.

[0024] Figure 3 For the utility model Figure 2A magnified view of the local structure.

[0025] Figure 4 It is a three-dimensional diagram of the electric heating tube in the utility model.

[0026] Figure 5 It is a three-dimensional diagram of the heating wire in the utility model.

[0027] In the figure: 1-pressure vessel tube, 2-electric heating tube, 21-electric heating outer tube, 22-magnesium oxide powder, 23-electric heating wire, 24-lead rod, 3-porous medium, 4-fluid inlet, 5-fluid outlet. DETAILED DESCRIPTION

[0028] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will become clearer. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0029] Embodiment 1:

[0030] like Figures 1 to 5 As shown, the embodiment of the utility model provides an electric heater with porous sintering, including: a pressure vessel tube 1; an electric heating tube 2, which is axially arranged in the pressure vessel tube 1; including an electric heating outer tube 21, magnesium oxide powder 22, an electric heating wire 23 and a lead rod 24; the electric heating outer tube 21 is axially inserted with a spiral-structured electric heating wire 23, and lead rods 24 are provided at both ends of the electric heating wire 23, and the gap between the electric heating outer tube 21 and the electric heating wire 23 and the lead rod 24 is filled with magnesium oxide powder 22; a porous medium 3, which is metal metallurgical powder or metal ball particles; is filled between the electric heating tube 2 and the pressure vessel tube 1. Due to the use of the porous medium 3 for heating, the equivalent diameter of the medium circulation is very small, the heat transfer coefficient is very high, the surface temperature of the electric heating tube 2 is further reduced, and the service life of the equipment is extended.

[0031] The heated fluid flows between the porous media 3, and the energy of the electric heating tube 2 is transferred through the heat conduction between the porous media 3, and on the other hand, part of the energy is radiated to the heated fluid through the heating of the electric heating tube 2. In addition, the fluid flows through the porous media 3, so the fluid has a certain pressure drop, which is particularly suitable for heating occasions with high fluid pressure and low flow rate.

[0032] The entire electric heater is heavy, has a large heat capacity during the heating process, and has strong resistance to temperature shock. At the same time, the equivalent diameter of the fluid flowing through the porous medium 3 is very small, and the heat transfer coefficient between the fluid and the porous medium 3 is very high. It is particularly suitable for long-term use of fluid heating at a temperature of about 1000°C.

[0033] On the basis of meeting a certain pressure drop requirement, the porous medium 3 is filled in a certain proportion according to a certain mesh number to improve the heat transfer performance of the porous medium 3 .

[0034] A temperature sensor is also included, and the electric heating tube 2 is in close contact with the temperature sensor.

[0035] The temperature sensor is closely attached to the outer electric heating tube 21 or inserted into the center of the magnesium oxide powder 22 to ensure the accuracy of the temperature sensor in measuring the temperature of the electric heating tube 2 and to accurately alarm.

[0036] The end of the electric heating tube 2 is connected to the lead rod 24 by a two-phase or three-phase power connector, and the junction box of the two-phase or three-phase power connector is designed with an explosion-proof structure.

[0037] Embodiment 2:

[0038] like Figure 1-5 As shown, on the basis of the above-mentioned embodiment 1, the electric heating tube 2, the porous medium 3 and the pressure vessel tube 1 are in close contact to ensure the heat transfer channel between the electric heating tube 2 and the porous medium 3, which is used to ensure the heat transfer channel between the electric heating tube 2 and the porous medium 3; after the filled porous medium 3 is vibrated and filled, the entire heater is sintered at a high temperature of 1050°C to improve the heat transfer channel of the porous medium 3.

[0039] Embodiment 3:

[0040] like Figure 1-5 As shown, on the basis of the above-mentioned embodiment 2, if the heated fluid of the electric heating outer tube 21 has the characteristic of absorbing radiation energy, the electric heating outer tube 21 can be coated with a high-temperature resistant high-emissivity coating to reduce the temperature of the electric heating outer tube 21.

[0041] The heating wire 23 inside the electric heating tube 2 can be designed for equal load as needed, that is, the power density of the electric heating tube 2 can be higher at the inlet due to the low fluid temperature, and conversely, at the outlet, the power density of the electric heating tube 2 can be lower.

[0042] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. An electric heater with porous sintering, characterized in that, include: Pressure vessel pipe (1); The electric heating tube (2) is axially arranged in the pressure vessel tube (1); it comprises an electric heating outer tube (21), magnesium oxide powder (22), an electric heating wire (23) and a lead rod (24); the electric heating wire (23) having a spiral structure is axially inserted in the electric heating outer tube (21), the lead rods (24) are arranged at both ends of the electric heating wire (23), and the gap between the electric heating outer tube (21) and the electric heating wire (23) and the lead rod (24) is filled with the magnesium oxide powder (22); The porous medium (3) is metal metallurgical powder or metal ball particles and is filled between the electric heating tube (2) and the pressure container tube (1).

2. An electric heater with porous sintering as claimed in claim 1, characterized in that: The pressure vessel tube (1), the electric heating tube (2) and the porous medium (3) are made of high-pressure forged shrink tubes.

3. An electric heater with porous sintering as claimed in claim 1, characterized in that: The porous medium (3) has a high degree of fullness, and the pressure vessel tube (1), the electric heating tube (2) and the porous medium (3) are made by high-temperature sintering at 1050°C.

4. An electric heater with porous sintering as claimed in claim 1, characterized in that: The porous medium (3) is filled in a proportion according to the mesh size to improve the heat transfer performance of the porous medium (3).

5. An electric heater with porous sintering as claimed in claim 1, characterized in that: The electric heating tube (2), the porous medium (3) and the pressure vessel tube (1) are in close contact with each other, so as to ensure a heat transfer channel between the electric heating tube (2) and the porous medium (3).

6. An electric heater with porous sintering as claimed in claim 1, characterized in that: The heating wire (23) adopts an equal load design, that is, the power density of the heating wire (23) is high at the fluid inlet (4) end, and the power density of the heating wire (23) is low at the fluid outlet (5) end.

7. An electric heater with porous sintering as claimed in claim 1, characterized in that: It also comprises a temperature sensor, and the electric heating tube (2) is in close contact with the temperature sensor.

8. An electric heater with porous sintering as claimed in claim 7, characterized in that: The temperature sensor is closely attached to the outer electric heating tube (21) or inserted into the center of the magnesium oxide powder (22) to ensure the accuracy of the temperature sensor in measuring the temperature of the electric heating tube (2) and to accurately alarm.

9. An electric heater with porous sintering as claimed in any one of claims 1 to 8, characterized in that: The outer wall of the electric heating outer tube (21) is coated with a high-temperature resistant high-radiation coefficient coating to reduce the temperature of the outer wall of the electric heating outer tube (21).

10. An electric heater with porous sintering as claimed in any one of claims 1 to 8, characterized in that: The end of the electric heating tube (2) is connected to the lead rod (24) by using a two-phase or three-phase power connector, and the junction box of the two-phase or three-phase power connector adopts an explosion-proof structure design.

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