阅读说明：本技术 等离子熔融炉及对其进行烘炉的方法 (Plasma melting furnace and method for baking same ) 是由 胡明 赵彬 宫臣 王婷婷 徐鹏程 宗肖 虎训 齐景伟 张亮 郭斌 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种等离子熔融炉,包括：电极,熔炉本体；所述熔炉本体包括炉壁、炉盖、炉底以及由所述炉壁、炉盖、炉底围成的炉腔,所述电极设置于所述炉底上；所述熔炉本体包括含有氧化铬的工作层。通过在工作层内掺杂氧化铬,工作层抗侵蚀、冲刷以及抗热震的形成提高,避免了碱金属元素的侵入,减小了工作层等耐火材料的损耗。(The invention discloses a plasma melting furnace, comprising: an electrode, a furnace body; the smelting furnace body comprises a furnace wall, a furnace cover, a furnace bottom and a furnace chamber enclosed by the furnace wall, the furnace cover and the furnace bottom, and the electrode is arranged on the furnace bottom; the furnace body includes a working layer comprising chromium oxide. By doping chromium oxide in the working layer, the erosion resistance, the scouring resistance and the thermal shock resistance of the working layer are improved, the invasion of alkali metal elements is avoided, and the loss of refractory materials such as the working layer is reduced.)

1. A plasma furnace, comprising:

an electrode, a furnace body;

the smelting furnace body comprises a furnace wall, a furnace cover, a furnace bottom and a furnace chamber enclosed by the furnace wall, the furnace cover and the furnace bottom, and the electrode is arranged on the furnace bottom;

the furnace body includes a working layer comprising chromium oxide.

2. The plasma furnace of claim 1 wherein the electrode comprises the first electrode comprising a plurality of spaced strips of conductive metal, the spaces filled with a non-conductive material.

3. The plasma furnace of claim 2, wherein the electrode further comprises a second electrode, the first electrode being stacked with the second electrode, the second electrode at least partially covering a surface of the hearth proximate the furnace chamber, the strip of conductive metal being partially disposed within the second electrode.

4. The plasma furnace of claim 1, further comprising

And the anti-permeation layer is arranged along the circumferential direction of the electrode.

5. The plasma furnace of claim 1 wherein the furnace body is further provided with a first thermal insulation layer, a second thermal insulation layer, and a flexible thermal insulation layer in that order.

6. The plasma melting furnace of claim 5 wherein the furnace walls comprise a first furnace wall and a second furnace wall arranged in segments, the first furnace wall is connected to the furnace cover, the second furnace wall is connected to the furnace bottom, the working layer of the first furnace wall has a chromium oxide content of 40% to 95%, the working layer of the second furnace wall has a chromium oxide content of 30% to 95%, and the working layer of the furnace cover has a chromium oxide content of 20% to 70%.

7. The plasma melting furnace of claim 5, wherein the thickness of the working layer on the first furnace wall is 280mm, the thickness of the first thermal insulation layer is 250mm, the thickness of the second thermal insulation layer is 200mm, and the thickness of the flexible thermal insulation layer is 10-100 mm.

8. The plasma melting furnace of claim 5, wherein the thickness of the working layer on the second furnace wall is 300mm, the thickness of the first thermal insulation layer is 300mm, the thickness of the second thermal insulation layer is 200mm, and the thickness of the flexible thermal insulation layer is 10-100 mm.

9. The plasma melting furnace of claim 5, wherein the furnace cover has a working layer thickness of 100-280mm, a second thermal insulation layer thickness of 100-400mm, and a flexible thermal insulation layer thickness of 10-100 mm.

10. A method of baking the plasma furnace of claim 1, comprising:

an electrode starting structure is sleeved on the electrode to start the electrode, and the electrode starting structure is positioned in the furnace cavity and has a preset distance from the furnace bottom;

arranging isolation parts on the electrode and the electrode starting structure to prevent materials outside the isolation parts from entering the electrode;

filling a first metal material on the electrode in the isolation part, and filling a second metal material on the furnace bottom outside the isolation part, wherein the first metal material covers the electrode starting structure;

and heating the plasma melting furnace to carry out furnace baking treatment.

11. The method of claim 10, further comprising

The oven is operated in at least two temperature zones.

Technical Field

The invention relates to the field of garbage treatment, in particular to a plasma melting furnace and a method for baking the plasma melting furnace.

Background

The fly ash generated by the incineration of the household garbage belongs to dangerous waste, and the current treatment mode aiming at the dangerous waste is mainly safe landfill and has higher cost. The fly ash can be innoxious, volume-reduced and recycled by the plasma melting technology. Because the plasma furnace is internally provided with a high-temperature cavity, refractory materials are required to be used for lining the plasma furnace so as to ensure the external operating environment and avoid heat loss. Due to the specificity of plasma fly ash melting furnaces, there are different requirements for refractory materials. Firstly, the plasma arc has stronger erosiveness to the traditional refractory material, and can be started and stopped instantly, so that the plasma arc is convenient to control and brings strong thermal shock to the refractory material; secondly, the fly ash contains a large amount of salts such as sodium chloride, potassium chloride and the like, so that the fly ash seriously erodes refractory materials; in addition, the high temperature of the plasma arc greatly increases the requirement for the thermal insulation of the refractory. Meanwhile, in the baking furnace process, an electric arc heating mode is adopted, so that the phenomena of uncontrollable temperature, uneven baking temperature, easiness in cracking and the like are caused.

The existing design of furnace body refractory materials usually uses refractory bricks, refractory castable or a combination form of refractory bricks, refractory castable and the like made of high-purity alumina, magnesia and the like as a working layer, the common design thickness is about 200mm, the outer layer is a water-cooling structure such as a close-packed water-cooling pipe or a water-cooling steel shell and the like, the cold surface of the refractory materials is directly contacted with the water-cooling structure, the refractory materials play a role in resisting erosion, and the heat of the refractory materials is taken away by cooling water. The refractory material structure in the whole plasma furnace body is divided into a furnace cover and a furnace body or is an integral structure.

Therefore, there is a need to provide a new technical solution to solve or partially solve the above problems.

Disclosure of Invention

In order to solve the above technical problem, an aspect of the present application provides a plasma melting furnace, including: an electrode, a furnace body; the smelting furnace body comprises a furnace wall, a furnace cover, a furnace bottom and a furnace chamber enclosed by the furnace wall, the furnace cover and the furnace bottom, and the electrode is arranged on the furnace bottom; the furnace body includes a working layer comprising chromium oxide.

Further, the electrode comprises the first electrode, the first electrode comprises a plurality of strip-shaped conductive metals which are mutually spaced, and the spaces are filled with non-conductive materials.

Further, the electrode further comprises a second electrode, the first electrode and the second electrode are stacked, the second electrode at least partially covers the surface of the furnace bottom close to the furnace chamber, and the strip-shaped conductive metal is partially positioned in the second electrode.

Further, the anti-seepage electrode also comprises an anti-seepage layer arranged along the circumferential direction of the electrode.

Furthermore, the furnace body is also provided with a first heat insulation layer, a second heat insulation layer and a flexible heat insulation layer in sequence.

Further, the furnace wall comprises a first furnace wall and a second furnace wall which are arranged in a segmented mode, the first furnace wall is connected with the furnace cover, the second furnace wall is connected with the furnace bottom, the chromium oxide content of a working layer of the first furnace wall is 40% -95%, the chromium oxide content of a working layer of the second furnace wall is 30% -95%, and the chromium oxide content of a working layer of the furnace cover is 20% -70%.

Further, the thickness of the working layer on the first furnace wall is 280mm and 100mm, the thickness of the first heat insulation layer is 250mm and 100mm, the thickness of the second heat insulation layer is 200mm and 100mm, and the thickness of the flexible heat insulation layer is 10mm to 100 mm.

Further, the thickness of the working layer on the second furnace wall is 300mm, the thickness of the first heat insulation layer is 300mm, the thickness of the second heat insulation layer is 200mm and the thickness of the flexible heat insulation layer is 10-100 mm.

Further, the thickness of the working layer of the furnace cover is 100-.

By doping chromium oxide in the working layer, the erosion resistance, the scouring resistance and the thermal shock resistance of the working layer are improved, the invasion of alkali metal elements is avoided, and the loss of refractory materials such as the working layer is reduced.

In another aspect of the present invention, a method for baking the plasma melting furnace is provided, which includes:

an electrode starting structure is sleeved on the electrode to start the electrode, and the electrode starting structure is positioned in the furnace cavity and has a preset distance from the furnace bottom;

arranging isolation parts on the electrode and the electrode starting structure to prevent materials outside the isolation parts from entering the electrode;

filling a first metal material on the electrode in the isolation part, and filling a second metal material on the furnace bottom outside the isolation part, wherein the first metal material covers the electrode starting structure;

and heating the plasma melting furnace to carry out furnace baking treatment.

Further, the oven is operated at least in two temperature zones.

The furnace body baked by the method is firm and durable and is not easy to deform.

Drawings

The invention is described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a plasma furnace according to an embodiment of the present application;

FIG. 2 is a schematic view of the structure of an electrode in a plasma melting furnace according to an embodiment of the present application;

FIG. 3 is a top view of an electrode start-up structure in a plasma furnace according to an embodiment of the present application;

FIG. 4 is another schematic view of an electrode start-up structure in a plasma melting furnace according to an embodiment of the present application;

FIG. 5 is a schematic view of the connection of an electrode start structure to a first electrode in a plasma melting furnace according to an embodiment of the present application;

FIG. 6 is a schematic view of a plasma furnace filled with a first metallic material and a second metallic material according to an embodiment of the present application;

FIG. 7 is a flow chart of a method of furnace baking a plasma melting furnace according to an embodiment of the present application;

reference numerals:

100: a furnace cover; 105: a first furnace wall; 110: a second furnace wall;

115: a first electrode; 120: an impermeable layer; 125: a second electrode;

130: a non-conductive material; 135: an aperture; 140: an electrode activation structure;

145: an isolation section;

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent that the practice of the invention is not limited to the specific details known to those skilled in the art of waste treatment. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity, and the same elements are denoted by the same reference numerals, and thus the description thereof will be omitted.

In the existing design, the used refractory materials are raw materials based on high-purity alumina, magnesia and the like, and because the fusion alkalinity is strong, in the area of a fused glass body, the corrosion is serious because of continuous scouring of molten slurry and the action of alkali metal and heavy metal components in the fused glass body, and the service life is only 3-6 months; in the free gasification area, due to the radiation effect of the plasma arc, and in addition, due to the volatilization of salts such as sodium chloride, potassium chloride and the like in the fly ash, part of the fly ash is gathered in the working layer of the refractory material, so that the service life of the part which is radiated by the plasma and corroded by alkali metal elements is greatly shortened.

Meanwhile, due to the huge thermal shock impact caused by the starting and stopping of the plasma arc, on one hand, a gap is easily formed on the contact surface of the steel shell and the refractory material, so that the problem of reduction of the heat conductivity coefficient is caused, and on the other hand, fine cracks are easily formed on the surface of the refractory material by the thermal shock, and a passage is formed for the invasion of alkali metal elements, so that the loss of the refractory material is aggravated.

To this end, the present application provides a plasma melting furnace comprising:

an electrode, a furnace body; the smelting furnace body comprises a furnace wall, a furnace cover, a furnace bottom and a furnace chamber enclosed by the furnace wall, the furnace cover and the furnace bottom, and the electrode is arranged on the furnace bottom; the furnace body includes a working layer comprising chromium oxide. The working layer means a portion directly contacting the molten glass body and the free-gasification zone, and the innermost layer of the furnace body.

By doping chromium oxide in the working layer, the erosion resistance, the scouring resistance and the thermal shock resistance of the working layer are improved, the invasion of alkali metal elements is avoided, and the loss of refractory materials such as the working layer is reduced.

The present application will be further explained and explained with reference to the drawings, wherein fig. 1 is a schematic structural diagram of a plasma melting furnace according to an embodiment of the present application; FIG. 2 is a schematic view of the structure of an electrode in a plasma melting furnace according to an embodiment of the present application; FIG. 3 is a top view of an electrode start-up structure in a plasma furnace according to an embodiment of the present application; FIG. 4 is another schematic view of an electrode start-up structure in a plasma melting furnace according to an embodiment of the present application; FIG. 5 is a schematic view of the connection of an electrode start structure to a first electrode in a plasma melting furnace according to an embodiment of the present application; FIG. 6 is a schematic view of a plasma furnace filled with a first metallic material and a second metallic material according to an embodiment of the present application; referring to fig. 1, the present invention includes an electrode, a furnace body; the smelting furnace body comprises a furnace wall, a furnace cover 100, a furnace bottom and a furnace chamber 130 enclosed by the furnace wall, the furnace cover 100 and the furnace bottom, and the electrodes are arranged on the furnace bottom; the furnace body includes a working layer comprising chromium oxide.

The electrode is disposed on the hearth for generating plasma arcs at a cathode (not shown) at the furnace opening for treating the fly ash in the furnace chamber 130. Specifically, the electrode comprises a first electrode, specifically, the first electrode 115 is arranged inside the furnace bottom with reference to fig. 1, wherein the first electrode comprises a plurality of mutually spaced strip-shaped conductive metals, and the spaces are filled with a non-conductive material.

Illustratively, the first electrode 115 comprises a plurality of metal conductive steel rods vertically spaced at the bottom of the furnace, the diameter of the steel rod electrode is between 20mm and 50mm, the material of the steel rod electrode can be ordinary carbon steel or other high-melting point metal materials, and a non-conductive refractory material layer is arranged at the space between the metal conductive steel rods, and the non-conductive refractory material layer comprises anti-seepage dry vibration materials and is combined with the first electrode 115 in a ramming material mode.

Further, the periphery of the electrode area can be made of a castable or masonry type to form a vertical compact impervious layer 120, and particularly as shown in fig. 1, the impervious layer 120 can prevent the upper molten liquid from penetrating through the dry vibrating material after vertical leakage to perform transverse leakage, so that the risk of furnace penetration is avoided.

Further, referring to fig. 2, a second electrode 120 is further disposed on the first electrode 115. The first electrode 115 is stacked with a second electrode 120, the second electrode 120 at least partially covering the surface of the furnace bottom near the furnace chamber, and the strip-shaped conductive metal of the first electrode 115 is partially located in the second electrode. In the melting operation process, due to the existence of the reserved molten steel, the method is equivalent to forming a metal electrode layer (a second electrode), the fly ash is heated and melted above the metal electrode layer, the melting fly ash is not in direct contact with a working layer of the refractory material any more, and the corrosion effect of alkali metal elements and chlorine elements in the melting fly ash on dry vibration material resistant materials is avoided; in addition, the direct action range of the electric arc exists above a metal electrode layer formed by reserved molten steel, and the damage of the plasma electric arc to dry vibrating materials is greatly reduced.

Furthermore, the furnace body can be sequentially provided with a first heat insulation layer, a second heat insulation layer and a flexible heat insulation layer outside the working layer. Meanwhile, the furnace wall comprises a first furnace wall 105 and a second furnace wall 110 which are arranged in sections, the first furnace wall 105 is connected with the furnace cover 100, the second furnace wall 110 is connected with the furnace bottom, and the working layer, the first heat insulation layer, the second heat insulation layer and the flexible heat insulation layer on the first furnace wall 105 are different from the working layer, the first heat insulation layer, the second heat insulation layer and the flexible heat insulation layer on the second furnace wall 110 in density, thickness and the like.

Illustratively, the working layer of the first furnace wall 105 is made of heavy castable, refractory brick or a combination thereof with a chromium oxide content of 40% -95%, and the main function of the working layer is to resist the corrosion of alkali metal elements in a free gasification zone and the radiation corrosion and thermal shock damage of a plasma arc, and the corrosion resistance, scouring resistance and thermal shock resistance of the refractory material are on the rising trend along with the increase of the chromium oxide content. The first thermal insulation layer can be made of medium-density thermal insulation castable, refractory bricks or a combination of the medium-density thermal insulation castable and the refractory bricks; the second heat insulation layer is made of light heat insulation castable, refractory bricks or a combination of the light heat insulation castable and the refractory bricks; the flexible thermal insulation layer is composed of rock wool, refractory fiber, nano thermal insulation material or a combination thereof, and is used for absorbing volume change generated along with thermal expansion and simultaneously reducing the temperature of the furnace shell to be below 80 ℃.

The working layer of the second furnace wall 110 is made of heavy castable with 30-95% of chromium oxide content, refractory bricks or a combination thereof, has a relative density of 2.5-3.5, and mainly has the main functions of bearing the corrosion of alkali metal elements and scouring the surface of the molten glass body in the deslagging process, and the corrosion resistance, scouring resistance and thermal shock resistance of the refractory material show an increasing trend along with the increase of the chromium oxide content. The working temperature of the hot surface of the layer is 1400-1650 ℃, the design thickness can be 100-300mm, the temperature of the cold surface is 800-1300 ℃, and the porosity of the working layer needs to be controlled below 3 percent so as to reduce the corrosion of heavy metal elements and alkali metal elements in the slag. The inner heat insulation layer is made of medium-density heat insulation casting materials, refractory bricks or a combination thereof, the relative density is 1.5-2.5, the inner heat insulation layer mainly bears the hot surface temperature of the working layer and plays a heat insulation role, the thickness is 300mm, the hot surface temperature is 800-1300 ℃, and the cold surface temperature is 400-700 ℃; the outer heat insulation layer is made of light heat insulation castable, refractory bricks or a combination of the light heat insulation castable and the refractory bricks, and is used for further insulating heat conduction, the relative density is 1-2.2, the thickness is 100-200mm, the hot surface temperature is 400-700 ℃, and the cold surface temperature is below 300 ℃. The flexible heat insulation layer is composed of rock wool, refractory fiber, nanometer heat insulation materials or a combination form thereof, the thickness is 10-100mm, the flexible heat insulation layer is used for absorbing volume change along with uneven thermal expansion, and simultaneously, the temperature of the furnace shell is further reduced to be below 80 ℃.

The working layer of the furnace cover 100 is made of heavy castable with 20-70% of chromium oxide content, refractory bricks or a combination thereof, and mainly plays a role in resisting the corrosion of alkali metal elements in a free gasification area and the radiation corrosion and thermal shock damage of a plasma arc. The heat insulating layer is made of medium-density heat insulating pouring materials, refractory bricks or a combination of the medium-density heat insulating pouring materials and the refractory bricks, and can be arranged into a single layer or a double-layer or multi-layer structure which is the same as that of the lower furnace wall. The flexible thermal insulation layer is composed of rock wool, refractory fiber, nano thermal insulation material or a combination thereof, and is used for absorbing volume change generated along with thermal expansion and simultaneously reducing the temperature of the furnace shell to be below 80 ℃. The thickness of each layer needs to be considered comprehensively, wherein the thickness of the working layer is in positive correlation with the erosion period of the working layer, so that the service life of the working layer is designed to be a multiple of the overhaul period in the common design, and the working layer is overhauled and repaired when in shutdown overhaul.

Referring to fig. 7, another aspect of the present application provides a method of baking the above-described melting furnace, comprising:

step 200: sleeving an electrode starting structure 140 on the first electrode 115 to start the electrode 115, wherein the electrode starting structure 140 is located in the furnace chamber 130 and has a preset distance from the furnace bottom;

referring to fig. 3, the electrode activating structure 140 is provided with a plurality of holes 135 through which the electrode activating structure is attached to the first electrode 115, and the electrode activating structure and the first electrode can be welded together in order to secure the electrode activating structure to the first electrode, and the welding angle should be not less than 20 mm.

The electrode starting structure 140 is a carbon steel plate having an outer diameter of 800mm and a thickness of 20mm, and the hole 135 of the steel plate at a position corresponding to each conductive metal rod may have a diameter of 50 mm.

After the construction of the furnace lining is finished, 50-150mm of refractory materials are exposed out of each strip-shaped conductive metal of the first electrode, the electrode starting structure 140 is sleeved on the strip-shaped conductive metal in the bottom electrode furnace, a gap (the gap is an upward expansion space of the furnace bottom refractory materials and prevents the furnace bottom refractory materials from expanding and extruding the electrode starting structure 140) of 10-30mm is reserved between the bottom surface of the electrode starting structure 140 and the surface of the furnace bottom refractory materials, the electrode starting structure 140 is leveled, and the strip-shaped conductive metals are exposed out of the communicating plates by about 30-55 mm.

Step 210: providing an isolation 145 on the electrode and the electrode activation structure to prevent material outside the isolation from entering the electrode;

the isolation portion 145 may be an open metal cylinder, for example, but may be other devices.

A metal cylinder (which can be a large round pipe with the outer diameter of phi 600-1200mm, the wall thickness of 5-10mm and the height of 700-1000 mm and made of common carbon steel) is placed at the bottom of the furnace, is positioned at the center of the furnace bottom, directly sits on a refractory material at the furnace bottom, and covers the electrode starting structure 140 and the first electrode inside.

Step 220: filling a first metal material on the first electrode 115 in the isolation portion 145, and filling a second metal material on the furnace bottom outside the isolation portion, wherein the first metal material covers the electrode starting structure;

wherein, the first metal material is paved: in the metal cylinder, a first electrode 115 (the first material may include steel scraps, the steel scraps may be steel particles or broken steel scraps generated during the operation of machine tools such as lathes and milling machines, the external dimension is about 3-10mm, the thickness is less than or equal to 2mm, the material is common carbon steel, the weight of the steel scraps is about 100-400kg, the steel scraps need oil-free and water-free), and the thickness of the first metal material is about 30-80mm higher than that of the first electrode 115, and is manually compacted, so as to fully contact the first metal material with the first electrode 115 and between the first metal material and the first electrode 115. Before filling, a multimeter can be used for measuring randomly in the first metal material stack, so that the first metal materials can be conducted, and the surface of the first metal materials is prevented from having a special surface layer which is insulated and not conductive.

Paving a second metal material, wherein the second metal material can be scrap steel, and the exemplary type of the scrap steel comprises the following steps of adopting a small round cake shape with the outline dimension of the scrap steel being approximately 20-50mm in diameter and 10-30mm in thickness, and adopting common carbon steel as the material. Before the second metal material is filled, a multimeter can be used for randomly measuring in the scrap steel pile, so that the scrap steel blocks can be conducted, and the surface of the scrap steel is prevented from having a special surface layer, so that the scrap steel is insulated and does not conduct.

And (3) filling a second metal material into the furnace: the second metal material in the furnace is filled in one time, and the total filling amount of the second metal material is 3-6t (adjusted according to the structure of the furnace body). The second metal material is first manually filled into the steel drum in the furnace and then the other scrap steel is piled up above and around the steel drum with reference to fig. 3, taking care to concentrate the second metal material as much as possible towards the center, the circle of distribution of the second metal material in the furnace preferably not exceeding a circle of phi 1400 mm.

Step 230: and heating the plasma melting furnace to carry out furnace baking treatment.

The temperature rise system of the plasma furnace baking oven depends on factors such as the structure, the material, the brick type and the masonry method of the furnace lining. According to the furnace drying system, the furnace drying time is 50-300 hours (mainly determined according to the design thickness of refractory materials, the furnace body volume and the building water content of the refractory materials), the furnace drying process is divided into a high-temperature section and a low-temperature section, wherein the low-temperature section within 1100 ℃ adopts fuel oil, fuel gas and other mineral fuel burners as heat sources, so that the temperature in the furnace is convenient to control; and heating and melting the second metal material by arc plasma in a high-temperature section above 1100 ℃ to form a molten pool. The furnace baking process is divided into 4-7 sections according to the furnace body sintering principle to continuously preserve heat, so that the temperature rising gradient is controllable, the temperature is uniform during furnace baking, and the baked furnace body is firm, durable and not easy to deform.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.