A device for controlling the air suction at the tail of a steel rolling heating furnace

Abstract

The present application relates to a device for controlling air suction at the tail of a steel rolling heating furnace, comprising: a heating furnace, wherein a heating furnace charging opening is provided in the middle of the right end of the heating furnace, and an inlet sealed chamber is fixedly provided at the right end of the heating furnace, wherein the inlet sealed chamber comprises a top wall and a sealed chamber end wall, a sealed chamber end wall is provided on the right side of the top wall, and a sealed chamber charging opening is provided in the middle of the sealed chamber end wall; an induced draft fan, wherein the air inlet of the induced draft fan is connected to a flue, and the air inlet of the flue is plugged into the middle of the top wall. The device provided in the embodiment of the present application ensures that the pressure at the charging door of the heating furnace is in equilibrium with the pressure inside the furnace, and the pressure difference between the pressure inside the tail and the pressure outside is zero. When the furnace door is opened, air outside the furnace will not enter the furnace, and the quality of the waste heat of the flue gas will not be reduced due to the inhalation of cold air. The device can also isolate the atmosphere inside the furnace of the heating furnace from the atmosphere outside the furnace, maintain the pressure inside the furnace, and control the oxygen content in the flue gas.

Description

Technical Field

[0001] The present application relates to the field of metallurgical energy technology, and in particular to a device for controlling air suction at the tail of a steel rolling heating furnace. Background Art

[0002] The charging door of a steel mill reheating furnace opens every two to three minutes to load ingots for heating. When the door is opened, the negative pressure at the rear of the furnace draws in a large amount of cold air from the surrounding environment through the holes created by the door opening. This cold air can reach up to 80% of the flue gas volume, mixing with the high-temperature flue gas before it is discharged into the flue. This significantly reduces the temperature of the flue gas leaving the furnace and degrades the quality of the flue gas's waste heat. Furthermore, when a large amount of cold air is drawn into the rear of the furnace, the oxygen in the air mixes with the flue gas, causing the oxygen content in the flue gas entering the chimney to be excessively high, even exceeding 10%, causing the converted NOx concentration to exceed the standard.

[0003] In order to avoid this, some companies adopt the method of increasing the furnace pressure of the heating furnace to prevent the inhalation of cold air, but this will cause fires to appear in other holes such as the heating furnace discharge door and peephole, which will not only cause heat loss when the flue gas is discharged into the environment, but also burn the equipment and instruments around the heating furnace.

[0004] Patent CN201620861591.6 "A horizontal annealing furnace entrance sealing device" sets up sealing rollers and nitrogen sealing chambers at the entrance of the horizontal annealing furnace. It seals the charging port by setting a very narrow roller gap at the charging furnace door to narrow the furnace door opening and introducing nitrogen. However, this method is more suitable for the production mode of thin steel strips with continuous loading. For hot rolling heating furnaces, due to the large thickness and mass of the continuous casting billets, the steel loader needs to lift them and load them into the furnace. This sealing method is not applicable.

[0005] In the prior art, the charging door of the heating furnace is opened every 2 to 3 minutes for charging. When the door is opened, the negative pressure in the rear of the furnace will draw in a large amount of cold air from the external environment through the opening formed when the door is opened. The amount of cold air sucked into the furnace can reach up to 80% of the flue gas volume. Such a large amount of cold air mixes with the flue gas before being discharged into the flue, causing the temperature of the flue gas discharged from the heating furnace to drop significantly, thereby reducing the quality of the flue gas waste heat.

[0006] The tail of the furnace inhales a large amount of cold air from the outside environment, which makes the oxygen content of the flue gas too high, even reaching more than 10%, causing NO x The converted concentration value exceeds the standard.

[0007] From the above, it can be seen that it is necessary to propose a sealing method and device for the tail of the heating furnace that can overcome the above-mentioned disadvantages, so as to prevent the heating furnace from inhaling cold air from the external environment during the process of loading the ingots, improve the exhaust flue gas temperature and waste heat quality, and prevent the excessive oxygen content in the flue gas from causing the pollutant conversion value to exceed the standard. Therefore, we proposed a device for controlling the suction at the tail of the steel rolling heating furnace. Summary of the Invention

[0008] The present application provides a device for controlling the air suction at the tail of a steel rolling heating furnace, so as to solve the problem in the existing technology that the heating furnace draws in cold air from the external environment during the process of loading ingots, thereby improving the exhaust flue gas temperature and waste heat quality, and preventing the excessive oxygen content in the flue gas from causing the pollutant conversion value to exceed the standard.

[0009] The present application provides a device for controlling the air suction at the tail of a steel rolling heating furnace, comprising:

[0010] A heating furnace, wherein a heating furnace charging opening is provided in the middle of the right end of the heating furnace, and an inlet sealed chamber is fixedly provided at the right end of the heating furnace, the inlet sealed chamber comprises a top wall and a sealed chamber end wall, a sealed chamber end wall is provided on the right side of the top wall, and a sealed chamber charging opening is provided in the middle of the sealed chamber end wall;

[0011] An induced draft fan, wherein the air inlet of the induced draft fan is connected to the flue, and the air inlet of the flue is inserted into the middle of the top wall.

[0012] Preferably, a furnace tail end wall is provided at the right end of the heating furnace, and a charging opening for the heating furnace is provided in the middle of the furnace tail end wall.

[0013] Preferably, a heating furnace flue is opened on the right side of the lower end of the heating furnace, and the right end of the heating furnace flue is connected to the heating furnace chimney.

[0014] Preferably, a waste heat recovery device is provided in the middle of the heating furnace flue.

[0015] Preferably, the air outlet of the induced draft fan is connected to an air cylinder.

[0016] Preferably, the interior of the heating furnace is provided with a moving steel billet to be heated.

[0017] Preferably, a pressure control valve is provided on the right side of the flue.

[0018] Preferably, a furnace pressure gauge is provided on the right side of the upper inner cavity of the heating furnace.

[0019] Preferably, a sealed chamber pressure gauge is connected to the upper portion of the inlet sealed chamber.

[0020] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0021] The device provided in the embodiment of the present application ensures that the pressure at the charging furnace door of the heating furnace is in a balanced state with the pressure inside the furnace, and the pressure difference between the pressure inside the furnace tail and the pressure outside is zero. When the furnace door is opened, since the pressure difference between the inside and outside of the tail end wall is zero, the air outside the furnace will not enter the furnace, and the waste heat quality of the flue gas will not be reduced due to the inhalation of cold air.

[0022] It can also isolate the atmosphere inside and outside the heating furnace, maintain the pressure inside the furnace, prevent the furnace from inhaling cold air from the environment, and control the oxygen content in the flue gas to avoid exceeding the oxygen content in the flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A schematic diagram of the overall structure of a device for controlling air suction at the tail of a steel rolling heating furnace provided in an embodiment of the present application;

[0026] Figure 2 This is an enlarged view of view A of a device for controlling air suction at the tail of a steel rolling heating furnace provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of gas flow for controlling tail air suction in a steel rolling heating furnace provided in an embodiment of the present application.

[0028] In the figure: 1. Heating furnace; 2. Heating furnace flue; 3. Heating furnace chimney; 4. Furnace tail end wall; 5. Inlet sealing chamber; 6. Flue; 7. Pressure control valve; 8. Air cylinder; 9. Induced draft fan; 10. Furnace pressure gauge; 11. Sealing chamber pressure gauge; 12. Heating furnace charging opening; 13. Sealing chamber charging opening; 14. Top wall; 15. Sealing chamber end wall; 90. Waste heat recovery device; 100. Steel billet. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] The various embodiments of the present application may be presented in the form of a range. It should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the present application. Therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, regardless of the range. In addition, whenever a numerical range is indicated in this application, it is intended to include any quoted number (fraction or integer) within the indicated range. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in this application are all commercially available or can be prepared using existing equipment.

[0031] In this application, unless otherwise specified, the directional words used, such as "upper" and "lower", specifically refer to the directions of the drawings in the accompanying drawings. In addition, in this application, the terms "including", "comprising", etc. mean "including but not limited to". In this application, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In this application, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this application, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c" or "at least one of a, b and c" can both mean: a, b, c, ab, i.e. a and b, ac, bc or abc, where a, b, c can be single or multiple.

[0032] like Figures 1 to 3As shown, the embodiment of the present application provides a device for controlling the air suction at the tail of a steel rolling heating furnace, comprising:

[0033] A heating furnace 1 is provided with a heating furnace charging opening 12 in the middle of the right end of the heating furnace 1, and an inlet sealed chamber 5 is fixedly provided at the right end of the heating furnace 1. The inlet sealed chamber 5 includes a top wall 14 and a sealed chamber end wall 15. The sealed chamber end wall 15 is provided on the right side of the top wall 14, and a sealed chamber charging opening 13 is provided in the middle of the sealed chamber end wall 15;

[0034] The induced draft fan 9 has an air inlet connected to the flue 6 , and the air inlet of the flue 6 is plugged into the middle of the top wall 14 .

[0035] Specifically, the sealed chamber pressure gauge 11, the furnace pressure gauge 10, the pressure control valve 7 and the induced draft fan 9 are all controlled by an external data processing mechanism, that is, according to the pressure measured by the sealed chamber pressure gauge 11 and the furnace pressure gauge 10, the induced draft fan 9 is started to control the opening of the pressure control valve 7 so that the pressure displayed by the furnace pressure gauge 10 measuring the furnace pressure at the tail end of the heating furnace 1 is equal to the pressure displayed by the sealed chamber pressure gauge 11 measuring the pressure of the inlet sealed chamber 5.

[0036] like Figure 1 As shown, a furnace tail end wall 4 is provided at the right end of the heating furnace 1 , and a heating furnace charging opening 12 is provided in the middle of the furnace tail end wall 4 .

[0037] like Figure 1 and Figure 2 As shown: a heating furnace flue 2 is opened on the right side of the lower end of the heating furnace 1, and the right end of the heating furnace flue 2 is connected to the heating furnace chimney 3.

[0038] like Figure 1 As shown: a waste heat recovery device 90 is provided in the middle of the heating furnace flue 2.

[0039] Specifically, the waste heat recovery device 90 uses existing waste heat equipment on the market to recover and utilize the heat in the flue gas and save energy.

[0040] like Figure 1 As shown: the air outlet of the induced draft fan 9 is connected to the air cylinder 8.

[0041] Specifically, the induced draft fan 9 adopts an existing fan on the market and is connected to an external data processing mechanism through a wire.

[0042] like Figure 1 As shown, a steel billet 100 to be heated is provided inside the heating furnace 1 .

[0043] Specifically, the steel billet 100 is a heated workpiece.

[0044] like Figure 1As shown: a pressure control valve 7 is provided on the right side of the flue 6.

[0045] Specifically, the pressure control valve 7 adopts an existing control valve on the market, and the pressure control valve 7 is connected to an external data processing mechanism through a wire.

[0046] like Figure 1 and Figure 2 As shown: a furnace pressure gauge 10 is provided on the right side of the upper inner cavity of the heating furnace 1.

[0047] Specifically, the furnace pressure gauge 10 adopts an existing pressure gauge on the market, which is a prior art. The furnace pressure gauge 10 is connected to an external data processing mechanism through a wire.

[0048] like Figure 1 and Figure 2 As shown: a sealed chamber pressure gauge 11 is connected to the upper part of the inlet sealed chamber 5.

[0049] Specifically, the sealed chamber pressure gauge 11 adopts an existing pressure gauge on the market, which is a prior art. The sealed chamber pressure gauge 11 is connected to an external data processing and control mechanism through a wire.

[0050] When the equipment is working, when not loading, the charging furnace door is in a closed state, and the induced draft fan 9 is in a closed state. The furnace of the heating furnace 1 is isolated from the external environment, and the furnace tail of the heating furnace 1 will not inhale cold air from the outside; when loading, the charging furnace door is opened, and the induced draft fan 9 is automatically turned on. The external data processing control controls the opening of the pressure control valve 7 so that the pressure displayed by the furnace pressure gauge 10 measuring the furnace pressure at the furnace tail of the heating furnace 1 is equal to the pressure displayed by the sealed chamber pressure gauge 11 measuring the pressure of the inlet sealed chamber 5. At this time, the internal and external pressures are balanced, and the furnace tail of the heating furnace 1 will not inhale cold air from the outside. The specific gas flow direction is: the high-temperature flue gas in the heating furnace 1 is opposite to the forward direction of the steel billet 100 in the heating furnace 1. It flows from the furnace head of the heating furnace 1 to the furnace tail, and then flows into the heating furnace flue 2 and enters the waste heat recovery device 90, and finally is discharged into the atmosphere through the heating furnace chimney 3 (such as Figure 3 As shown). Under the suction force of the induced draft fan 9, the outside air enters the sealed chamber 5 from the sealed chamber charging opening 13, and is then discharged into the atmosphere through the flue 6, the pressure control valve 7, the induced draft fan 9 and the air cylinder 8, without entering the inner cavity of the heating furnace 1 and having no impact.

[0051] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but rather is intended to conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A device for controlling the air suction at the tail of a steel rolling heating furnace, characterized in that: include: A heating furnace (1), wherein a heating furnace charging opening (12) is provided in the middle of the right end of the heating furnace (1), and an inlet sealed chamber (5) is fixedly provided at the right end of the heating furnace (1), wherein the inlet sealed chamber (5) comprises a top wall (14) and a sealed chamber end wall (15), a sealed chamber end wall (15) is provided on the right side of the top wall (14), and a sealed chamber charging opening (13) is provided in the middle of the sealed chamber end wall (15); An induced draft fan (9), the air inlet of the induced draft fan (9) being connected to the flue (6), and the air inlet of the flue (6) being plugged into the middle of the top wall (14); A pressure control valve (7) is provided on the right side of the flue (6), a furnace pressure gauge (10) is provided on the right side of the upper inner cavity of the heating furnace (1), and a sealed chamber pressure gauge (11) is plugged into the upper part of the inlet sealed chamber (5); According to the pressures measured by the sealed chamber pressure gauge and the furnace pressure gauge, the induced draft fan is started and the opening of the pressure control valve is controlled so that the pressure displayed by the furnace pressure gauge measuring the furnace pressure at the tail furnace of the heating furnace is equal to the pressure displayed by the sealed chamber pressure gauge measuring the inlet sealed chamber pressure.

2. The device for controlling air suction at the tail of a steel rolling heating furnace according to claim 1, characterized in that: The right end of the heating furnace (1) is provided with a furnace tail end wall (4), and the heating furnace charging opening (12) is opened in the middle of the furnace tail end wall (4).

3. The device for controlling air suction at the tail of a steel rolling heating furnace according to claim 1, characterized in that: A heating furnace flue (2) is provided on the right side of the lower end of the heating furnace (1), and the right end of the heating furnace flue (2) is connected to the heating furnace chimney (3).

4. The device for controlling air suction at the tail of a steel rolling heating furnace according to claim 3, characterized in that: A waste heat recovery device (90) is provided in the middle of the heating furnace flue (2).

5. The device for controlling air suction at the tail of a steel rolling heating furnace according to claim 1, characterized in that: The air outlet of the induced draft fan (9) is connected to the air cylinder (8).

6. The device for controlling air suction at the tail of a steel rolling heating furnace according to claim 1, characterized in that: A steel billet (100) to be heated is provided inside the heating furnace (1).

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