A kind of auxiliary nitrogen placement device suitable for converter splashing nitrogen system

Abstract

The utility model provides a kind of auxiliary nitrogen placement device suitable for converter splashing slag nitrogen gas system, belong to steel metallurgical equipment technical field, it is applied to converter splashing slag nitrogen gas system, it includes: setting in the nitrogen gas lance of banana bend export below evaporative cooler;The nitrogen gas lance is connected with nitrogen gas supply main pipeline;Valve group is arranged between the nitrogen gas lance and nitrogen gas supply main pipeline;The valve group includes electric control valve;The opening and closing of electric control valve in the splashing slag nitrogen gas control point of converter splashing slag nitrogen gas system is utilized.This device effectively cooperates converter oxygen lance to blow nitrogen, while reducing oxygen content in flue gas, further shorten blowing nitrogen time, to effectively avoid the explosion venting accident caused by internal oxygen content exceeding standard in electrostatic precipitator.

Description

Technical Field

[0001] This utility model relates to the field of iron and steel metallurgical equipment technology, and in particular to an auxiliary nitrogen supply device applicable to the nitrogen gas system for converter slag splashing. Background Technology

[0002] The converter LT dry dust removal system is the core purification equipment for converter smelting flue gas. With its highly efficient dust removal and environmental protection effects, and excellent energy-saving performance, it has been increasingly widely used in domestic steel enterprises. Converter flue gas contains solid particles such as iron oxide and gaseous components such as carbon monoxide and oxygen. The electrostatic precipitator is the main part of the converter dry dust removal system that removes solid particles. It contains several sets of cathode plates and anode wires. An electric field environment is created between the cathode plates and anode wires through discharge. Dust floating in this environment is adsorbed and removed under the action of the electric field, thus purifying the converter flue gas. When carbon monoxide and oxygen in the flue gas reach a certain mixing ratio, they can explode upon contact with an open flame, damaging the electrostatic precipitator shell and internal equipment, forcing the converter to shut down for an extended period.

[0003] During converter blowing, situations such as slag discharge midway through oxygen blowing or blowing at the end of the blowing process necessitate secondary oxygen blowing. This can easily lead to excessive oxygen content, potentially causing an explosion in the electrostatic precipitator. To prevent the formation of an explosive gas mixture from carbon monoxide and oxygen, the oxygen content in the mixed gas must be strictly controlled (below 14%). Existing equipment uses oxygen lances to blow nitrogen to reduce the oxygen content in the flue gas. However, because the oxygen lances need to blow nitrogen into the converter body, some nitrogen is lost, resulting in low nitrogen utilization and a slow reduction in flue gas oxygen content, only reaching 16%-17%.

[0004] Therefore, there is an urgent need for a device that can further reduce the oxygen content of flue gas in the initial stage of converter blowing (below 14%), while also accelerating the rate of oxygen content reduction. Summary of the Invention

[0005] To address the aforementioned technical problem of nitrogen loss due to the need for oxygen lances to blow nitrogen into the converter body, an auxiliary nitrogen supply device suitable for converter slag splashing nitrogen systems is provided. This invention primarily utilizes a nitrogen nozzle located at the banana-shaped outlet below the evaporator cooler to supply nitrogen, thereby accelerating the reduction of oxygen content.

[0006] The technical means adopted in this utility model are as follows: An auxiliary nitrogen supply device for a converter slag splashing nitrogen system, applicable to the converter slag splashing nitrogen system, comprising: A nitrogen nozzle is installed at the banana-bend outlet below the evaporative cooler; the nitrogen nozzle is connected to the main nitrogen supply pipeline. A valve assembly is installed between the nitrogen nozzle and the main nitrogen supply pipeline; the valve assembly includes electrically controlled valves. The opening and closing of the electrically controlled valve at the nitrogen control point of the slag splashing system in the converter slag splashing system is utilized.

[0007] Furthermore, the valve assembly also includes: First manual control valve and second manual control valve; The electrically controlled valve is positioned between the first manually controlled valve and the second manually controlled valve.

[0008] Furthermore, the diameter of the nitrogen nozzle is determined based on the nitrogen flow rate required for the actual flue gas flow rate during converter smelting.

[0009] Furthermore, multiple nozzles are provided at the end of the nitrogen nozzle near the banana-bend outlet below the evaporative cooler.

[0010] Furthermore, the nozzles are evenly spaced and uniformly arranged.

[0011] Furthermore, a check valve is provided between the nozzle and the first manual control valve.

[0012] Furthermore, the control of the opening and closing of the electrically controlled valve using the slag splashing nitrogen control point in the converter slag splashing nitrogen system includes: The electrically controlled valves and the oxygen lance slag splashing nitrogen valves in the converter slag splashing nitrogen system are interlocked and open synchronously. When the oxygen content detected by the gas analyzer in the converter slag splashing nitrogen system is below 15%, the electrically controlled valve is shut off.

[0013] Compared with the prior art, the present invention has the following advantages: A nitrogen nozzle is inserted into the flue at the banana-bend outlet below the evaporative cooler. This is combined with nitrogen blowing from the converter oxygen lance to reduce the oxygen content in the flue gas and further shorten the nitrogen blowing time. This effectively prevents the electrostatic precipitator from experiencing a leak or explosion due to excessive internal oxygen content.

[0014] The nitrogen nozzle of this device is equipped with five nozzles installed in the east, south, west, north and center, with the nozzle outlet facing the direction of flue gas flow. The five nozzles are evenly distributed on the cross-section of the flue gas flow to ensure that the nitrogen is fully and evenly mixed with the converter flue gas.

[0015] This device designs the nitrogen nozzle diameter based on the actual flue gas flow rate required during converter smelting, effectively preventing the formation of explosive gases from the mixture of carbon monoxide and oxygen.

[0016] The nitrogen nozzle of this device is equipped with a check valve to prevent the coal gas in the converter smelting flue gas from flowing back into the nitrogen nozzle.

[0017] The device has manual valves installed on both sides of the electrically controlled valve for use when replacing the intermediate pneumatic valve. The intermediate pneumatic valve operates frequently, and if it is damaged, the manual valves on both sides can be closed simultaneously to complete the replacement.

[0018] When nitrogen curtain is created before the second lower lance of the converter, the electrically controlled valves in this device open synchronously with the nitrogen valves for slag splashing from the oxygen lance. The opening and closing are automatically controlled by the converter nitrogen blowing signal and the oxygen content displayed by the gas analyzer. No additional devices are required. The structure is simple, easy to operate, and easy to implement.

[0019] Based on the above reasons, this utility model can be widely promoted in the fields of steel metallurgical equipment, etc. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the auxiliary nitrogen supply device for the converter slag splashing nitrogen system in this embodiment of the present invention.

[0022] In the diagram: 1. Nozzle; 2. Check valve; 3. First manual control valve; 4. Electrically controlled valve; 5. Second manual control valve; 6. Nitrogen spray pipe. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0027] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0028] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0029] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0030] This utility model provides an auxiliary nitrogen supply device for a converter slag splashing nitrogen system. By inserting a nitrogen nozzle into the flue at the banana bend outlet below the evaporator cooler, nitrogen is supplied to dilute and inertify the oxygen in the flue gas before the secondary bottom lance blowing of multiple converters.

[0031] Example like Figure 1 As shown, this utility model provides an auxiliary nitrogen supply device for a converter slag splashing nitrogen system, which is applied to the converter slag splashing nitrogen system and includes: The nitrogen nozzle 6 is located at the banana bend outlet below the evaporator cooler. The nitrogen nozzle is connected to the main nitrogen supply pipeline. A valve group is installed between the nitrogen nozzle and the main nitrogen supply pipeline. The valve group includes an electrically controlled valve 4, which is opened and closed by the electrically controlled valve 4 at the nitrogen control point of the slag splashing nitrogen system in the converter slag splashing nitrogen system.

[0032] The valve assembly also includes: a first manual control valve 3 and a second manual control valve 4, with the electrically controlled valve 4 positioned between the first manual control valve 3 and the second manual control valve 5.

[0033] The diameter of the nitrogen nozzle 6 is designed based on the nitrogen flow rate required for the actual flue gas flow rate during converter smelting. In this embodiment, the nitrogen flow rate is designed to be 15000. The diameter of nitrogen nozzle 6 is 150 mm. .

[0034] Multiple nozzles 1 are installed at the end of the nitrogen nozzle 6 near the banana-shaped outlet below the evaporator cooler. The nozzles 1 are evenly spaced and uniformly arranged.

[0035] A check valve is installed between the nozzle and the first manual control valve. The opening and closing of the electrically controlled valve at the slag splashing nitrogen control point in the converter slag splashing nitrogen system includes: the electrically controlled valve and the oxygen lance slag splashing nitrogen valve in the converter slag splashing nitrogen system are interlocked and opened synchronously. When the oxygen content detected by the gas analyzer in the converter slag splashing nitrogen system is less than 15%, the electrically controlled valve is closed.

[0036] A nitrogen injection pipe is installed inside the banana-bend outlet flue below the evaporative cooler, along with an external nitrogen valve assembly. When secondary lower-lance blowing occurs during converter blowing, it can effectively coordinate with the converter oxygen lance for nitrogen blowing, reducing the oxygen content in the flue gas and further shortening the blowing time. This effectively prevents explosion accidents caused by excessive internal oxygen content in the electrostatic precipitator.

[0037] To ensure more thorough and uniform mixing of nitrogen with the converter flue gas, five nozzles (east, south, west, north, and center) are installed at the outlet of the nitrogen nozzle in the banana-bend flue. These nozzles are connected to the main nitrogen pipeline and supplied by the main nitrogen pipeline. The five nozzles are evenly distributed across the flue gas flow section, with the nozzle outlet facing the direction of flue gas flow. To effectively prevent the formation of an explosive gas mixture of carbon monoxide and oxygen, the nominal diameter of the nitrogen nozzle is designed based on the nitrogen volume required by the flue gas flow rate during converter smelting. To prevent backflow of coal gas from the converter smelting flue gas into the nitrogen nozzle, a check valve is installed on the nitrogen nozzle. To effectively conserve nitrogen consumption, the nitrogen nozzle supply system is equipped with an automatic pneumatic shut-off valve. The opening and closing of the pneumatic shut-off valve is automatically controlled by the converter slag splashing nitrogen blowing signal and the oxygen content displayed by the coal gas analyzer.

[0038] After installing this device, the oxygen content in the flue gas before secondary oxygen blowing in the converter is reduced (below 14%), and the time required to reduce the oxygen content is shortened, increasing production efficiency. The calculation is as follows: Before the improvement, there were an average of 1.5 secondary lance-down incidents per shift, each lasting 4 minutes; after the improvement, the time for each nitrogen blowing is shortened to 2 minutes. The annual non-maintenance downtime saved by the three converters is: (4-2) minutes / time * 1.5 times / shift * 3 shifts / day * 365 days / year = 3285 minutes / year. The converter process calendar operation rate is 78.125%, the average converter output is 260 tons, the average smelting time is 45 minutes, the fixed cost per ton of steel is approximately 89.83 yuan / ton of steel, and the contribution coefficient is 80%. The increased production efficiency of the three converters = reduced time * calendar operation rate / process production cycle * average furnace output * fixed cost per ton of steel * number of converters. The economic benefit of reducing downtime = 3285 * 78.125% / 45 * 260 * 89.83 * 80% = 1,065,600 yuan / year.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An auxiliary nitrogen supply device for a converter slag splashing nitrogen system, characterized in that, include: A nitrogen nozzle (6) is installed at the banana-bend outlet below the evaporative cooler; the nitrogen nozzle is connected to the main nitrogen supply pipeline. A valve group is provided between the nitrogen nozzle and the main nitrogen supply pipeline; the valve group includes an electrically controlled valve (4). The opening and closing of the electrically controlled valve (4) at the slag splashing nitrogen control point in the converter slag splashing nitrogen system includes: The electrically controlled valve (4) and the oxygen lance splashing nitrogen valve in the converter splashing nitrogen system are interlocked and open synchronously; When the oxygen content detected by the gas analyzer in the converter slag splashing nitrogen system is below 15%, the electrically controlled valve is shut off.

2. The apparatus according to claim 1, characterized in that, The valve assembly also includes: First manual control valve (3) and second manual control valve; The electrically controlled valve (4) is located between the first manually controlled valve (3) and the second manually controlled valve (5).

3. The apparatus according to claim 1, characterized in that, The diameter of the nitrogen nozzle (6) is determined based on the nitrogen flow rate required by the actual flue gas flow rate during converter smelting.

4. The apparatus according to claim 1, characterized in that, Multiple nozzles (1) are provided at the end of the nitrogen nozzle (6) near the banana bend outlet below the evaporator.

5. The apparatus according to claim 1, characterized in that, The nozzles (1) are evenly spaced and uniformly arranged.

6. The apparatus according to claim 4, characterized in that, A check valve (2) is provided between the nozzle (1) and the first manual control valve (3).

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