High-temperature-resistant through-wall electrode

Abstract

The utility model relates to the technical field of through-wall electrodes, in particular to a high-temperature-resistant through-wall electrode which comprises an electrode core and an external insulating cylinder made of high-voltage ceramics, and a ceramic-like brazing flux layer with the expansion rate similar to that of the high-voltage ceramics is arranged between the electrode core and the external insulating cylinder. The electrode core and the external insulating cylinder are welded together through a ceramic-like brazing flux layer, the thickness of the ceramic-like brazing flux layer is 0.5-0.8 mm, and welding flanges are arranged on the electrode core and located at the two ends of the external insulating cylinder in a vacuum brazing mode. The metal similar to the high-voltage ceramic is used as the surface electrode on the surface of the internal electrode, and meanwhile, the ceramic-like brazing flux layer with the same expansion rate as the high-voltage ceramic is used for welding, so that the wall-penetrating electrode can be quickly welded when the wall-penetrating electrode is subjected to the same temperature and pressure rise; and fracture caused by relative abnormal movement due to different linear expansion is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to a through -wall electrode technical field, specifically is a kind of high-temperature-resistant through -wall electrode. BACKGROUND

[0002] Through -wall electrode is a kind of device for realizing electric signal or electric energy transmission in closed system, many through -wall electrode devices are designed in the world, and use environment is basically in low temperature low pressure even vacuum state.

[0003] But the through -wall electrode in prior art, especially boiler in high temperature high pressure state, the linear expansion coefficient of high-pressure ceramic is relatively low, the linear expansion coefficient of metal electrode is relatively high, when through -wall electrode is heated, metal electrode can be loose due to expansion length exceeding the expansion length of high-pressure ceramic between metal electrode and high-pressure ceramic and appear leakage, when further fastening, if high-pressure ceramic appears fracture after heating and pressure increasing, leakage and breakdown will appear, which will endanger the life and safety of operating personnel. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of high-temperature-resistant through -wall electrode to solve the problems raised in the above background.

[0005] The utility model can be realized by the following technical solutions:

[0006] A kind of high-temperature-resistant through -wall electrode, including electrode core and the outer insulation cylinder made of high-pressure ceramic, the electrode core and outer insulation cylinder between being provided with and high-pressure ceramic expansion rate similar ceramic brazing flux layer, electrode core and outer insulation cylinder are welded together by ceramic brazing flux layer, the thickness of ceramic brazing flux layer is 0.5-0.8mm.

[0007] Welding flange is vacuum brazed on the electrode core and located at the both ends of outer insulation cylinder, welding flange is fixedly connected with the first sealing ring with trapezoidal cross section on the side close to outer insulation cylinder, outer insulation cylinder is provided with sealing ring groove with trapezoidal cross section at both ends, first sealing ring is located in sealing ring groove, stress release micropore is arranged in the inside of outer insulation cylinder, and both ends of stress release micropore are communicated with the sealing ring groove of both ends of outer insulation cylinder.

[0008] Preferably, the side of both welding flanges away from outer insulation cylinder is fixedly connected with threaded pipe opening, and threaded connection is achieved between end insulation flange and one threaded pipe opening, and threaded connection is achieved between insulating extension cylinder and the other threaded pipe opening.

[0009] Preferably, the ceramic brazing flux layer is composed of silver-based solder, molybdenum powder and aluminum powder.

[0010] Preferably, the electrode core comprises an inner electrode made of conductive metal and a surface electrode made of metal similar to high-voltage ceramic in linear expansion, which is fixedly connected to the outer surface of the inner electrode.

[0011] Preferably, the thickness of the surface electrode is 1.2-2.6 mm.

[0012] Preferably, the radius of the stress release micro-hole is 2-3.5 mm.

[0013] The utility model discloses the beneficial effect that:

[0014] The utility model discloses a through -wall electrode, because on the surface of inner electrode adopts the metal as surface electrode with high -voltage ceramic similar, same ceramic soldering flux layer that adopts with high -voltage ceramic expansion rate is welded with welding, can make through -wall electrode when receiving same temperature and pressure increase, will not appear because the relative motion of linear expansion difference and appear fracture, when using under the high -pressure state of boiler, it is not easy to appear leakage and breakdown because of linear expansion, guarantee the security of through -wall electrode use. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, below will be to the embodiment or prior art description needed to use the drawing briefly introduce, obviously, for the ordinary skilled person in the art comes, under the premise of not paying the creative labor, can also obtain other drawings according to these drawings;

[0016] Figure 1 It is the whole structure schematic diagram of the utility model;

[0017] Figure 2 It is the side view of the utility model Figure 1 In welding flange;

[0018] Figure 3 It is the back view of the utility model Figure 2 In welding flange;

[0019] Figure 4 It is the structure schematic diagram of the utility model Figure 1 In electrode core.

[0020] The reference signs in the drawing are as follows:

[0021] 1, electrode core;101, inner electrode;102, surface electrode;2, external insulation cylinder;201, stress release micro -hole;3, ceramic soldering flux layer;4, welding flange;401, first sealing ring;5, threaded pipe mouth;6, end insulation flange;7, insulation extension cylinder. DETAILED DESCRIPTION

[0022] Clearly, the described embodiments are merely a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts under the premise that no creative efforts are made, belong to the scope of protection of the present application.

[0023] As Figure 1 A high-temperature-resistant through-wall electrode comprises an electrode core 1 and an external insulating cylinder 2 made of high-voltage ceramic, a ceramic-like brazing flux layer 3 with a similar expansion rate to the high-voltage ceramic is arranged between the electrode core 1 and the external insulating cylinder 2, the electrode core 1 and the external insulating cylinder 2 are welded together through the ceramic-like brazing flux layer 3, and the thickness of the ceramic-like brazing flux layer 3 is 0.5-0.8 mm.

[0024] The electrode core 1 and the external insulating cylinder 2 are both components of the through-wall electrode in the prior art, and the ceramic-like brazing flux layer 3 with a thickness of 0.5-0.8 mm can not only ensure the welding strength, but also avoid the relative movement caused by the different expansion of the wires and the fracture caused by the relative movement.

[0025] As Figure 1 And Figure 2 The electrode core 1 is vacuum brazed with a welding flange 4 at both ends of the external insulating cylinder 2, the vacuum brazing of the welding flange 4 adopts a brazing flux with the same material as the ceramic-like brazing flux layer 3, one side of the welding flange 4 close to the external insulating cylinder 2 is fixedly connected with a first sealing ring 401 with a trapezoidal cross section, and the two ends of the external insulating cylinder 2 are provided with sealing ring grooves with trapezoidal cross sections, so that the first sealing ring 401 can be clamped into the sealing ring grooves when the welding flange 4 is welded at the two ends of the insulating sleeve 2, the sealing between the welding flange 4 and the insulating sleeve 2 is realized, and the air tightness of the electrode core is ensured.

[0026] As Figure 1 The internal part of the external insulating cylinder 2 is provided with stress release micro-holes 201, the two ends of the stress release micro-holes 201 are communicated with the sealing ring grooves at the two ends of the external insulating cylinder 2, and the stress release micro-holes 201 can release stress when the external insulating cylinder 2 expands, so that the external insulating cylinder 2 itself will not be broken due to thermal expansion and contraction.

[0027] As Figure 1 And Figure 3 The other side of the two welding flanges 4 away from the external insulating cylinder 2 is fixedly connected with a threaded pipe 5, one of the threaded pipes 5 is threadedly connected with an end insulating flange 6, and the other threaded pipe 5 is threadedly connected with an insulating extension cylinder 7, the outer surface of the threaded pipe 5 is provided with threads, and the end insulating flange 6 and the insulating extension cylinder 7 are provided with internal threads to realize the threaded connection with the threaded pipe 5.

[0028] The ceramic-like brazing flux layer 3 is composed of silver-based solder, molybdenum powder and aluminum powder.

[0029] The ceramic-like brazing flux layer 3 composed of silver-based solder, molybdenum powder and aluminum powder is the prior art, which has similar high-pressure ceramic expansion rate, excellent tensile strength and shear strength, and its manufacturing method is as follows:

[0030] Step one: material preparation and mixing

[0031] 1. Select the base material:

[0032] Select silver-based solder (such as Ag-Cu-Ti) as the base material because it has good wettability and strength.

[0033] 2. Add the adjusting agent:

[0034] Add low-expansion materials (such as tungsten, molybdenum) or high-expansion materials (such as aluminum) to adjust the thermal expansion coefficient of the agent.

[0035] For example, add 5% molybdenum powder and 3% aluminum powder to the silver-based solder.

[0036] 3. Mix the materials:

[0037] Mix the silver-based solder powder and the adjusting agent powder in proportion;

[0038] Use a ball mill to ball mill the mixture for 4-6 hours to ensure uniform mixing.

[0039] 4. Heat pretreatment:

[0040] Heat the mixed powder to 60°C to remove adsorbed water and volatile substances.

[0041] Step two: preparation of the flux blank

[0042] 1. Press forming:

[0043] Put the uniformly mixed powder into the mold and use the press to press the blank under a pressure of 200-300 MPa.

[0044] 2. Pre-sintering:

[0045] Heat the blank to 600-700 under inert gas (such as argon) protection for 1-2 hours for pre-sintering to enhance the strength of the blank.

[0046] Step three: sintering and densification

[0047] 1. High-temperature sintering:

[0048] The pre-sintered blank is heated to 800-900 DEG C in vacuum or inert gas environment, and is kept for 2-3 hours, so that it is completely sintered and densified.

[0049] 2. Cooling:

[0050] Slowly cool to room temperature to avoid internal stress caused by rapid cooling.

[0051] Finally, cutting and surface polishing are performed.

[0052] As Figure 1 and Figure 4 The electrode core 1 comprises an inner electrode 101 made of conductive metal and a surface electrode 102 made of metal similar to the expansion of high-pressure ceramic, and the surface electrode 102 is fixedly connected to the outer surface of the inner electrode 101.

[0053] As Figure 1 and Figure 4 The thickness of the surface electrode 102 is 1.2-2.6mm, and the metal similar to the expansion of high-pressure ceramic has poor conductivity, and the thickness is preferably 1.2-2.6mm.

[0054] As Figure 1 The radius of the stress release micro-hole 201 is 2-3.5mm, and the radius of 2-3.5mm facilitates the realization through conventional mechanical processing or drilling technology, reduces the processing difficulty and cost, and the micro-hole with the radius can effectively disperse the stress concentration in the material, reduce the stress peak, and reduce the crack risk.

[0055] Compared with the related art, the through-wall electrode provided by the utility model has the following beneficial effects:

[0056] The through-wall electrode provided by the utility model adopts metal similar to high-pressure ceramic as the surface electrode 102 on the surface of the inner electrode 101, and is welded by a ceramic-like soldering flux layer 3 with the same expansion rate as high-pressure ceramic, so that the through-wall electrode will not be broken due to relative movement caused by different linear expansions when subjected to the same temperature and pressure increase, and is not easy to leak and be broken when used in a high-pressure state of a boiler, thereby ensuring the safety of the through-wall electrode.

[0057] The basic principle, main features and advantages of the utility model are shown and described above. Those skilled in the art should understand that the utility model is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principle of the utility model, and various changes and improvements can be made without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model claimed.

Claims

1. A high-temperature-resistant through-wall electrode comprising an electrode core (1) and an outer insulating cylinder (2) made of high-pressure ceramic, characterized in that, The electrode core (1) and the outer insulation cylinder (2) are provided with a ceramic-like brazing flux layer (3) with similar expansion rate to high-voltage ceramic, the electrode core (1) and the outer insulation cylinder (2) are welded together through the ceramic-like brazing flux layer (3), and the thickness of the ceramic-like brazing flux layer (3) is 0.5-0.8mm; The electrode core (1) is vacuum brazed with a welding flange (4) at both ends of the outer insulation cylinder (2), the welding flange (4) is fixedly connected with a first sealing ring (401) with a trapezoidal cross section on the side close to the outer insulation cylinder (2), the outer insulation cylinder (2) is provided with a sealing ring groove with a trapezoidal cross section at both ends, the first sealing ring (401) is located in the sealing ring groove, and the inner part of the outer insulation cylinder (2) is provided with a stress release micro-hole (201) in communication with the sealing ring groove at both ends of the outer insulation cylinder (2).

2. The high temperature resistant through-wall electrode of claim 1, wherein, The two welding flanges (4) are fixedly connected with threaded pipe mouths (5) away from the outer insulation cylinder (2), one threaded pipe mouth (5) is threadedly connected with an end insulation flange (6), and the other threaded pipe mouth (5) is threadedly connected with an insulation extension cylinder (7).

3. The high temperature resistant through-wall electrode of claim 1, wherein, The electrode core (1) comprises an inner electrode (101) made of conductive metal and a surface electrode (102) made of metal with similar expansion to high-voltage ceramic wire, and the surface electrode (102) is fixedly connected to the outer surface of the inner electrode (101).

4. The high temperature resistant through-wall electrode of claim 3, wherein, The thickness of the surface electrode (102) is 1.2-2.6mm.

5. The high temperature resistant through-wall electrode of claim 1, wherein, The radius of the stress release micro-hole (201) is 2-3.5mm.

Images