A new type of silicon nitride ceramic heating rod

Abstract

The utility model discloses a novel silicon nitride ceramic heating rod, including cylinder, top cover, wire, heating element. The cylinder is silicon nitride ceramic cylinder, and the top cover is the silicon nitride ceramic round sheet of edge slotting, and the alloy wire passes through the silicon nitride ceramic top cover through the slot, and is welded together with tungsten wire heating element. The gap between cylinder, top cover and wire is sealed after brazing material melts and sintering. The space below top cover is the vacuum state of airtightness. After wire energization, heating element generates heat for heating. The utility model has simple process, low requirement to production equipment and high yield.

Description

Technical Field

[0001] This utility model belongs to the field of heating rods, specifically relating to a novel silicon nitride ceramic heating rod. Background Technology

[0002] Ceramic heating rods are used as heating elements in ignition mechanisms. They rapidly reach extremely high temperatures when energized, thus igniting the flame. Applications include fuel and gas ignition, such as engine ignition, gas stove ignition, and water heater ignition. Ceramic heating rods offer advantages such as rapid start-up, high temperature resistance, corrosion resistance, high strength, and long lifespan.

[0003] Existing ceramic heating rod technologies either involve all-ceramic heating rods formed using a slip casting method, resulting in low yields due to factors such as slip uniformity. Alternatively, the ceramic outer layer of the heating wire is formed by dry pressing, followed by hot pressing and sintering, and finally, grinding and finishing the shape. These processes are numerous, the forming and sintering equipment is bulky, and the output is low.

[0004] This invention employs a prefabricated ceramic cylinder combined with clever design features such as brazing sealant. The process is simple, saving labor and increasing the yield rate. The ceramic shell can be produced without the need for large-scale hot-pressing and sintering equipment, offering advantages such as high temperature resistance, corrosion resistance, high strength, and long service life. Summary of the Invention

[0005] The purpose of this invention is to provide a novel silicon nitride ceramic heating rod to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a novel silicon nitride ceramic heating rod, comprising a cylinder, a top cover, a wire, and a heating element. The cylinder is a silicon nitride ceramic cylinder; the top cover is a silicon nitride ceramic disc with grooved edges; the alloy wire passes through the grooves of the silicon nitride ceramic top cover and is welded to the tungsten filament heating element. The gaps between the cylinder, top cover, and wire are sealed by melting and sintering with brazing filler metal. The space below the top cover is a sealed vacuum. When the wire is energized, the heating element generates heat for heating.

[0007] The entire outer shell consists of two parts: a ceramic cylinder and a top cover. The interior of the outer shell is sealed. Alloy wires pass through the top cover and are connected to the heating element.

[0008] The ceramic cylinder is a single piece. The ceramic top cover has round holes or grooves on the edges to allow alloy wires to pass through.

[0009] The outer casing is sealed using brazing filler metal. The internal sealed space of the casing is a vacuum or filled with nitrogen or argon. The heating element is made of nickel-chromium alloy, iron-chromium-aluminum alloy, or tungsten.

[0010] The present invention has the following advantages: 1. The outer shell of the present invention is made of silicon nitride ceramic, which is resistant to high temperature, has good thermal conductivity, is non-conductive, has high strength, and is corrosion resistant. It can withstand harsh working environments and has a long service life.

[0011] 2. Compared with heating rods that use conductive ceramics as heating elements, this utility model has a higher yield rate.

[0012] 3. Compared with heating rods where the heating wire is completely encased in ceramic, this utility model does not require the outer shell and heating wire to be dry-pressed together, which simplifies the process and saves labor and equipment.

[0013] 4. The ceramic cylinder and top cover of this utility model are prefabricated parts, which do not require vacuum hot pressing sintering, have low equipment requirements, and are convenient for mass production.

[0014] 5. The shape of this utility model is a smooth cylinder when the sintering is completed, and no post-processing or shaping is required. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a novel silicon nitride ceramic heating rod.

[0016] Figure 2 This is a schematic diagram of a novel silicon nitride ceramic heating rod, viewed from top to bottom.

[0017] In the diagram: 1. Cylinder body; 2. Top cover; 3. Alloy wire; 4. Brazing filler; 5. Heating element. Detailed Implementation

[0018] The technical solutions in some embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments provided by this utility model, all other embodiments obtained by those skilled in the art are within the protection scope of this utility model. Example

[0019] like Figure 1 and Figure 2The embodiment shown in this application provides a novel silicon nitride ceramic heating rod, comprising a cylinder 1, a top cover 2, a wire 3, brazing filler 4, and a heating element 5. The cylinder 1 is a silicon nitride ceramic cylinder; the top cover 2 is a silicon nitride ceramic disc with grooved edges; the alloy wire 3 passes through the grooves of the silicon nitride ceramic top cover 2 and is welded to the U-shaped tungsten wire heating element 5. Vacuum brazing filler 4 is placed in the gaps between the ceramic cylinder 1 and the ceramic top cover 2, and in the gaps between the ceramic top cover 2 and the alloy wire 3. The entire assembly is placed in a vacuum heating furnace. At this time, the heating furnace and the ceramic cylinder 1 are filled with air. The brazing filler 4 is not airtight before melting and sintering. The air in the vacuum heating furnace is evacuated, creating a vacuum state, and the ceramic cylinder 1 is also in a vacuum state. The vacuum heating furnace is heated, and the brazing filler 4 melts and sinters. After cooling, the brazing filler 4 seals the gaps between the cylinder 1, the top cover 2, and the wire 3. The interior of the cylinder 1 below the top cover 2 is in a sealed vacuum state. When wire 3 is energized, the U-shaped tungsten wire 5 generates high temperature for heating. The vacuum state inside the cylinder protects the tungsten wire 5 from oxidation by air.

[0020] In some embodiments of this application, the diameter of the alloy wire 3 is 0.8-1.2 mm.

[0021] In some embodiments of this application, the heating element 5 is a nickel-chromium alloy, an iron-chromium-aluminum alloy, or a tungsten wire with a diameter of 0.2-0.5 mm.

[0022] In some embodiments of this application, the thickness of the cylinder 1 and the top cover 2 is 0.5-1 mm. The cylinder 1 is 30-40 mm long and has an outer diameter of 4-6 mm. The channel through which the wire 3 passes on the top cover 2 can be a circular hole or an edge slot. This application does not specifically limit this aspect.

[0023] In some embodiments of this application, after the air in the vacuum heating furnace is evacuated to create a vacuum, nitrogen or argon can be introduced. The resulting sealed space within the cylinder 1 below the top cover 2 will then be filled with nitrogen or argon to protect the tungsten filament from oxidation.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel silicon nitride ceramic heating rod, wherein a ceramic top cover (2) seals the heating element (5) inside a ceramic cylinder (1); characterized in that: The entire outer shell consists of two parts: a ceramic cylinder (1) and a top cover (2); The interior of the outer shell is sealed. The alloy wire (3) passes through the top cover (2) and is connected to the heating element (5).

2. The novel silicon nitride ceramic heating rod according to claim 1, characterized in that: The outer casing is sealed with brazing filler metal (4).

3. The novel silicon nitride ceramic heating rod according to claim 1, characterized in that: The internal sealed space of the outer shell is a vacuum or filled with nitrogen or argon.

4. The novel silicon nitride ceramic heating rod according to claim 1, characterized in that: The heating element (5) is made of nickel-chromium alloy, iron-chromium-aluminum alloy or tungsten.

5. A novel silicon nitride ceramic heating rod according to claim 1, characterized in that: The ceramic top cover (2) has a round hole or an edge groove for the alloy wire (3) to pass through.

6. The novel silicon nitride ceramic heating rod according to claim 1, characterized in that: The ceramic cylinder (1) is a prefabricated whole.

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