A method for external gas chamber gas inlet for gas-based shaft furnace

Abstract

The present application relates to the technical fields of gas-based shaft furnace, and discloses an external gas chamber air inlet method for gas-based shaft furnace, comprising the following steps: S1, the steel shell arrangement of the gas-based shaft furnace is designed first, the upper gas chamber steel shell at the air inlet gas chamber G is first left empty, and the shaft furnace steel shell is divided into two parts; S2, after the upper and lower steel shells of the shaft furnace are supported and fixed by the shaft furnace tower steel structure, the refractory is poured or built, and the annular gas chamber steel shell is reserved with the air inlet port communicated with the high-temperature pipeline; S3, the refractory around the gas chamber is built from the outside through the channel left empty at the upper part of the gas chamber, and the refractory inside the gas-based shaft furnace is built from the inside of the shaft furnace; the external gas chamber air inlet method greatly reduces the construction difficulty and enhances the refractory structure performance by optimizing the position structure of the gas chamber and the shaft furnace and the refractory building form, and in the present application, the gas is ensured to enter the gas-based shaft furnace smoothly and uniformly; and the refractory building near the air inlet port of the gas-based shaft furnace is convenient, and the structure strength of the gas chamber and the refractory near the gas chamber is enhanced.

Description

Technical Field

[0001] This invention relates to the field of gas-based vertical shaft furnace technology, and more specifically discloses an external gas chamber gas inlet method for a gas-based vertical shaft furnace. Background Technology

[0002] The mainstream direct reduction process in the world today is gas-based direct reduction, mainly Midrex and HYL.

[0003] The gas-based vertical shaft furnace mainly consists of an upper arched roof, followed by a cylindrical section, an angled trapezoidal column section near the reducing gas inlet, and a conical section at the bottom. The reducing gas inlet is a ring-shaped gas chamber built with refractory material. A square or circular hole of appropriate size is reserved below the gas chamber near the interior of the vertical shaft furnace to ensure that the gas is evenly fed into the furnace.

[0004] The furnace charge flows downwards, while the reducing gas flows upwards. The furnace charge and reducing gas react under certain pressure and temperature to produce direct reduced iron, which is then discharged from the vertical furnace through the cone section and the unloading valve.

[0005] The gas chambers for the gas intake of existing gas-based vertical shaft furnaces are all located inside the steel shell of the furnace. The gas chambers are formed by casting and lining refractory materials inside the steel shell of the furnace, leaving gas vents. The reducing gas then enters the annular gas chamber through a high-temperature pipeline, and then enters the furnace through the reserved vents.

[0006] according to Figure 1 It is known that the gas chamber and vent are entirely constructed from refractory casting and masonry. After the steel structure is erected, the refractory material in the gas chamber area needs to be masonry inside the vertical furnace, which places higher demands on the masonry work and makes it more difficult. Poor masonry can easily lead to quality problems, such as refractory material falling off after the furnace is started.

[0007] Gas-based vertical shaft furnaces are high-pressure operating equipment. During normal production, the pressure in the gas chamber is higher than the pressure inside the furnace, meaning there is a pressure difference between the gas chamber and the furnace. If the high-temperature gas inlet is partially blocked, the pressure difference between the gas chamber and the furnace will increase, which may cause the refractory material in the refractory wall near the furnace to fall off.

[0008] During the charging, shutdown, or startup of the vertical furnace, the refractory material near the interior of the furnace in the gas chamber is constantly under pressure fluctuations. Over time, this can easily lead to loosening or even detachment of the refractory material. Summary of the Invention

[0009] This invention provides an external gas chamber inlet method for gas-based vertical shaft furnaces, which can solve the problems of difficult masonry and easy refractory material detachment caused by the traditional internal gas chamber of vertical shaft furnaces.

[0010] To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a method for external gas chamber inlet for a gas-based vertical shaft furnace, comprising the following steps:

[0011] S1. For the gas-based vertical shaft furnace, first design the steel shell layout. Leave the upper gas chamber steel shell at the gas inlet (G) empty. The vertical shaft furnace steel shell is then divided into upper and lower parts. The upper part is shown in the attached diagram. Figure 3 As shown, attached Figure 3 The steel shell needs to be supported by the steel structure of the vertical furnace tower, the lower part as shown in the attached figure. Figure 4 As shown, attached Figure 4 The steel shell needs to be supported by the steel structure of the vertical furnace tower;

[0012] S2. After the upper and lower steel shells of the vertical furnace are supported and fixed by the steel structure of the vertical furnace tower, refractory materials are poured or laid, including... Figure 4 The steel shell of the annular gas chamber must have an air inlet for connection with a high-temperature pipeline, as shown in the attached diagram. Figure 2 Point A in the middle;

[0013] S3. The refractory material around the gas chamber is laid from the outside through the channel opened at the top of the gas chamber. The refractory material inside the gas-based vertical furnace is laid from the inside of the vertical furnace. The refractory material at the connection between the gas chamber and the inside of the vertical furnace is laid with refractory material with reserved ventilation holes. The part where the refractory material contacts the furnace shell is grouted.

[0014] S4. After the refractory lining or pouring inside the gas chamber and the vertical furnace near the gas chamber is completed, the upper steel shell of the gas chamber is welded to the inner and outer ring steel shells of the gas chamber as one piece, and then grouting is carried out through the grouting hole to make the refractory material fully contact the upper steel shell of the gas chamber.

[0015] S5. The refractory material of the external gas chamber and the refractory material inside the vertical furnace are baked to form a strong and high-temperature resistant external gas chamber. High-temperature gas enters the interior of the vertical furnace through the external gas chamber and the pressure-equalized vent.

[0016] Furthermore, in step S2, the arrangement of refractory materials is designed according to the external air chamber structure, refractory material performance, and insulation requirements. The specific arrangement of refractory materials such as refractory bricks or castables is designed by the designer according to the specific circumstances.

[0017] Furthermore, in step S3, the internal refractory material of the vertical furnace and the external gas chamber refractory material are constructed simultaneously, with the gas chamber section being constructed starting from the bottom of the gas chamber.

[0018] Furthermore, the upper steel shell of the air chamber is provided with a grouting hole H, through which grout is injected to ensure that the refractory material is in full contact with the upper steel structure.

[0019] Furthermore, the overall structure of the air chamber adopts an annular air chamber with a rectangular cross-section.

[0020] Furthermore, an external water jacket is welded onto the steel shell of the air chamber for cooling.

[0021] Furthermore, the internal refractory material of the vertical furnace is connected to the external gas chamber refractory material, and the high-temperature gas inlet passes through the overlapping refractory material, allowing the reducing gas to enter the vertical furnace from the gas chamber.

[0022] Furthermore, the high-temperature gas vents are evenly distributed at the bottom of the annular gas chamber, and each high-temperature gas vent has the same shape and cross-sectional area, and the shape of the high-temperature gas vent is square or circular.

[0023] The beneficial effects of the external gas chamber inlet method for a gas-based vertical shaft furnace of the present invention are as follows:

[0024] In this invention, the external gas chamber air intake method greatly reduces construction difficulty and enhances the performance of refractory structure by optimizing the position and structure of the gas chamber and the vertical furnace and the refractory masonry form.

[0025] In this invention, the gas is ensured to enter the gas-based vertical shaft furnace smoothly and evenly; and the refractory material masonry near the gas inlet of the gas-based vertical shaft furnace is convenient, which enhances the structural strength of the gas chamber and the surrounding refractory material.

[0026] In this invention, the air chamber is located outside, and the pressure of the air chamber is applied to the steel shell through the refractory material, which reduces the pressure fluctuation of the refractory material around the air chamber, thereby reducing the possibility of the refractory material loosening and falling off, and extending the service life of the refractory material. Attached Figure Description

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0028] Figure 1 This is a structural diagram of the traditional built-in gas chamber gas inlet method of a gas-based vertical shaft furnace;

[0029] Figure 2 A structural diagram of a novel external gas chamber gas inlet system for a gas-based vertical shaft furnace;

[0030] Figure 3 This is a schematic diagram of the gas chamber annulus and the steel shell structure of the vertical furnace above;

[0031] Figure 4 This is a schematic diagram of the outer ring of the gas chamber and the steel shell structure of the vertical furnace below. Detailed Implementation

[0032] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0033] According to the appendix Figure 2-4 A method for external gas chamber inlet for a gas-based vertical shaft furnace is provided, comprising the following steps:

[0034] S1. For the gas-based vertical shaft furnace, first design the steel shell layout. Leave the upper gas chamber steel shell at the gas inlet (G) empty. The vertical shaft furnace steel shell is then divided into upper and lower parts. The upper part is shown in the attached diagram. Figure 3 As shown, attached Figure 3 The steel shell needs to be supported by the steel structure of the vertical furnace tower, the lower part as shown in the attached figure. Figure 4 As shown, attached Figure 4 The steel shell needs to be supported by the steel structure of the vertical furnace tower;

[0035] S2. After the upper and lower steel shells of the vertical furnace are supported and fixed by the steel structure of the vertical furnace tower, refractory materials are poured or laid, including... Figure 4 The steel shell of the annular gas chamber must have an air inlet for connection with a high-temperature pipeline, as shown in the attached diagram. Figure 2 Point A in the middle;

[0036] S3. The refractory material around the gas chamber is laid from the outside through the channel opened at the top of the gas chamber. The refractory material inside the gas-based vertical furnace is laid from the inside of the furnace. The refractory material at the connection between the gas chamber and the inside of the furnace is laid with refractory material with reserved ventilation holes. The contact part between the refractory material and the furnace shell is grouted. The refractory material inside the vertical furnace can be laid straight up and down. The structure is simple, the casting is convenient, the laying is easy, the laying quality is improved, and the strength of the refractory material is enhanced.

[0037] S4. After the refractory lining or pouring inside the gas chamber and the vertical furnace near the gas chamber is completed, the upper steel shell of the gas chamber is welded to the inner and outer ring steel shells of the gas chamber as one piece, and then grouting is carried out through the grouting hole to make the refractory material fully contact the upper steel shell of the gas chamber.

[0038] S5. The refractory material of the external gas chamber and the refractory material inside the vertical furnace are baked to form a strong and high-temperature resistant external gas chamber. High-temperature gas enters the interior of the vertical furnace through the external gas chamber and the pressure-equalized vent.

[0039] In this embodiment, in step S2, the arrangement of refractory materials is designed according to the external air chamber structure, refractory material performance and insulation requirements. The specific arrangement of refractory materials such as refractory bricks or castables is designed by the designer according to the specific situation.

[0040] In this embodiment, in step S3, the internal refractory material of the vertical furnace and the external gas chamber refractory material are constructed simultaneously. The gas chamber is constructed from the bottom of the gas chamber, which reduces the difficulty of construction, saves construction time, and increases the overall strength of the refractory material in this part.

[0041] In this embodiment, to facilitate refractory material masonry, the steel shell (attached) at the upper part of the air chamber is removed before masonry. Figure 2 (At point G) a space is left empty beforehand. After the refractory lining inside the gas chamber is completed, the upper steel shell is sealed and welded in sections. The upper part of the gas chamber is attached... Figure 2 A grouting hole H is pre-reserved in the upper steel shell of the air chamber at point G, as shown in the attached document. Figure 2 At point H, grouting is performed through grouting hole H to ensure full contact between the refractory material and the upper steel structure.

[0042] In this embodiment, the overall structure of the gas chamber adopts an annular gas chamber with a rectangular cross-section, and the steel shell of the gas chamber and the steel shell of the vertical furnace are finally welded together.

[0043] In this embodiment, an external water jacket is welded onto the steel shell of the air chamber for cooling.

[0044] In this embodiment, the refractory material inside the vertical furnace is connected to the refractory material of the external gas chamber, and the high-temperature gas inlet passes through the overlapping refractory material, allowing the reducing gas to enter the vertical furnace from the gas chamber.

[0045] In this embodiment, the high-temperature gas vents are evenly distributed at the bottom of the annular gas chamber. Each high-temperature gas vent has the same shape and cross-sectional area, and the shape of the high-temperature gas vent is square or circular.

[0046] This invention employs an external air chamber structure for air intake, the specific structural form of which is shown in the attached figure. Figure 2 As shown.

[0047] The refractory lining of the external gas chamber is constructed by lining from the outside of the vertical furnace (e.g.) Figure 2 As shown, a supporting structure is required near point D of the upper steel structure of the vent to prevent most of the weight of the upper part of the vertical furnace from acting on the refractory material at the connection between the gas chamber and the vertical furnace.

[0048] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.

Claims

1. A method for external gas chamber air intake in a gas-based vertical shaft furnace, characterized in that: Includes the following steps: S1. The steel shell layout of the gas-based vertical furnace is designed first. The upper gas chamber steel shell at the gas inlet (G) is left empty. The vertical furnace steel shell is divided into upper and lower parts, and the upper and lower parts of the vertical furnace steel shell are supported by the vertical furnace tower steel structure. S2. After the upper and lower steel shells of the vertical furnace are supported and fixed by the steel structure of the vertical furnace tower, refractory materials are poured or laid. The steel shell of the annular gas chamber should be reserved to allow for the high-temperature gas inlet to be connected to the high-temperature pipeline. S3. The refractory material around the gas chamber is laid from the outside through the channel opened at the top of the gas chamber. The refractory material inside the gas-based vertical furnace is laid from the inside of the vertical furnace. The refractory material at the connection between the gas chamber and the inside of the vertical furnace is laid with refractory material with reserved ventilation holes. The part where the refractory material contacts the furnace shell is grouted. S4. After the refractory lining or pouring inside the gas chamber and the vertical furnace near the gas chamber is completed, the upper steel shell of the gas chamber is welded to the inner and outer ring steel shells of the gas chamber as one piece, and then grouting is carried out through the grouting hole to make the refractory material fully contact the upper steel shell of the gas chamber. S5. The refractory material of the external gas chamber and the refractory material inside the vertical furnace are baked to form a strong and high-temperature resistant external gas chamber. High-temperature gas enters the interior of the vertical furnace through the external gas chamber and the pressure-equalized vent.

2. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 1, characterized in that: In step S2, the arrangement of refractory materials is designed according to the external air chamber structure, refractory material performance and insulation requirements. The specific arrangement of refractory bricks or castable refractory materials is designed by the designer according to the specific situation.

3. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 2, characterized in that: In step S3, the internal refractory material of the vertical furnace and the external gas chamber refractory material are constructed simultaneously, and the gas chamber is constructed starting from the bottom of the gas chamber.

4. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 3, characterized in that: The upper steel shell of the air chamber has a pre-reserved grouting hole (H), through which grout is injected to ensure full contact between the refractory material and the upper steel structure.

5. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 4, characterized in that: The overall structure of the air chamber adopts an annular air chamber with a rectangular cross-section.

6. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 5, characterized in that: An external water jacket is welded onto the steel shell of the air chamber for cooling.

7. The external gas chamber air intake method for a gas-based vertical shaft furnace according to claim 6, characterized in that: The internal refractory material of the vertical furnace is connected to the external gas chamber refractory material. The high-temperature gas inlet passes through the overlapping refractory material, allowing the reducing gas to enter the vertical furnace from the gas chamber.

8. The external gas chamber inlet method for a gas-based vertical shaft furnace according to claim 7, characterized in that: The high-temperature gas vents are evenly distributed at the bottom of the annular gas chamber. Each high-temperature gas vent has the same shape and cross-sectional area, and the shape of the high-temperature gas vent is square or circular.

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