A semi-closed submerged arc furnace flue gas treatment system

Abstract

The utility model discloses a semi-enclosed submerged arc furnace flue gas treatment system, including a submerged arc furnace body, a smoke hood, a smoke pipe, a smoke purification system, and a chimney; it also includes a clean smoke pipe, a clean smoke circulation fan, and a clean smoke valve; a clean smoke outlet is provided on the side wall of the chimney, a clean smoke inlet is provided on the hood wall of the smoke hood, and the clean smoke outlet and the clean smoke inlet are connected through the clean smoke pipe, the clean smoke valve, and the clean smoke circulation fan. The advantages are: simple operation, convenient use, can effectively reduce the denitration cost in the production process of the submerged arc furnace, and has universal applicability; the treated part of the smoke is sent into the smoke hood and the submerged arc furnace through the clean smoke pipe, the clean smoke circulation fan, and the clean smoke valve, which effectively reduces the oxygen content in the submerged arc furnace, thereby reducing the initial nitrogen oxide generation and the denitration cost; at the same time, after the smoke enters the submerged arc furnace, the material surface temperature is increased, and the preheating time before the combustibles on the material surface are reduced, which is conducive to the increase of the output of the submerged arc furnace.

Description

Technical field:

[0001] The utility model relates to the technical field of fume treatment of submerged arc furnaces, in particular to a semi-closed fume treatment system of submerged arc furnaces. Background technology:

[0002] During the smelting process of semi-enclosed submerged arc furnace, a certain amount of nitrogen oxides will be produced and discharged with the flue gas. According to different sources, the nitrogen oxides in the flue gas can be divided into raw material-introduced nitrogen oxides and high-temperature nitrogen oxides. Among them, raw material-introduced nitrogen oxides refer to nitrogen oxides generated by the chemical reaction between nitrogen contained in raw materials such as ore and coal and oxygen. The amount of nitrogen oxides generated by raw material-introduced nitrogen oxides is related to the content of nitrogen compounds in the raw materials; high-temperature nitrogen oxides refer to nitrogen oxides generated by the reaction of nitrogen in the atmosphere with oxygen under high temperature and discharge. It is the NO formed in the production process of submerged arc furnace. x the main way.

[0003] At present, the control of flue gas nitrogen oxides in the smelting process of the electric arc furnace mainly stays at the end denitrification, such as using SCR (selective catalytic reduction reaction denitrification) or ozone oxidation denitrification process for denitrification. The above measures can reduce the nitrogen oxides generated in the smelting process of the electric arc furnace to the emission standards, but require higher construction costs and daily operating costs. Utility model content:

[0004] The utility model aims to provide a semi-enclosed submerged arc furnace fume treatment system which is easy to operate and can effectively reduce the production cost of the submerged arc furnace.

[0005] The utility model is implemented by the following technical scheme: a semi-enclosed submerged arc furnace flue gas treatment system, comprising a submerged arc furnace body, a smoke hood, a smoke duct, a smoke purification system, and a chimney; the smoke hood is arranged directly above the submerged arc furnace body, the gas outlet end of the smoke hood is connected with the gas inlet end of the smoke purification system through the smoke duct, and the gas outlet end of the smoke purification system is connected with the chimney; it also includes a clean smoke duct, a clean smoke circulation fan, and a clean smoke valve;

[0006] A clean smoke outlet is provided on the side wall of the chimney, and a clean smoke inlet is provided on the hood wall of the smoke hood. The clean smoke outlet is connected to the clean smoke inlet through the clean smoke pipe, the clean smoke valve and the clean smoke circulation fan.

[0007] Preferably, it further comprises a furnace inlet nozzle; the clean smoke inlet is arranged on the top wall of the smoke hood, and the air inlet end of the furnace inlet nozzle is fixedly connected and communicated with the clean smoke inlet.

[0008] Preferably, it also includes a PLC controller, an oxygen content tester, and a nitrogen oxide content tester; the oxygen content tester and the nitrogen oxide content tester are fixedly arranged in the chimney; the clean flue gas valve, the clean flue gas circulation fan, the oxygen content tester, and the nitrogen oxide content tester are all electrically connected to the PLC controller.

[0009] Preferably, it further comprises a waste heat boiler; the waste heat boiler is arranged between the air outlet end of the smoke hood and the air inlet end of the flue gas purification system.

[0010] The advantages of the utility model are: simple operation, easy use, can effectively reduce the denitrification cost in the production process of the submerged arc furnace, and has universal applicability; part of the treated flue gas is sent into the smoke hood and the submerged arc furnace through the clean flue gas pipeline, the clean flue gas circulation fan, and the clean flue gas valve, which effectively reduces the oxygen content in the submerged arc furnace, thereby reducing the generation of nitrogen oxides in the submerged arc furnace and the denitrification cost; at the same time, after the flue gas enters the submerged arc furnace, the material surface temperature is increased, and the preheating time before the combustion of combustibles on the material surface is reduced, which is conducive to increasing the output of the submerged arc furnace. Description of the drawings:

[0011] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 This is a schematic diagram of the structure of Example 1 of the utility model.

[0013] Figure 2 This is a schematic diagram of the PLC controller control of Example 1.

[0014] Figure 3 This is a schematic diagram of the structure of Example 2.

[0015] Submerged arc furnace body 1, smoke hood 2, flue gas duct 3, flue gas purification system 4, chimney 5, clean flue gas duct 6, clean flue gas outlet 6.1, clean flue gas inlet 6.2, clean flue gas circulation fan 7, clean flue gas valve 8, PLC controller 9, oxygen content tester 10, nitrogen oxide content tester 11, furnace inlet nozzle 12, waste heat boiler 13. Specific implementation method:

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] Embodiment 1:

[0018] like Figure 1 A semi-enclosed submerged arc furnace flue gas treatment system shown includes a submerged arc furnace body 1, a smoke hood 2, a smoke pipe 3, a smoke purification system 4, and a chimney 5; specifically, the smoke hood 2 is arranged directly above the submerged arc furnace body 1, the gas outlet end of the smoke hood 2 is connected to the gas inlet end of the smoke purification system 4 through the smoke pipe 3, and the gas outlet end of the smoke purification system 4 is connected to the chimney 5. Among them, this part is a mature existing technology in the field of submerged arc furnace flue gas treatment, which does not belong to the innovation of the utility model, and will not be repeated here. The smoke purification system 4 can use a universal smoke purification system 4 that can achieve dust removal, denitrification, and desulfurization.

[0019] As an improvement of the present utility model, the semi-closed ore-fired furnace flue gas treatment system also includes a clean flue gas pipeline 6, a clean flue gas circulation fan 7, a clean flue gas valve 8, a PLC controller 9, an oxygen content tester 10, and a nitrogen oxide content tester 11.

[0020] Specifically, an oxygen content tester 10 and a nitrogen oxide content tester 11 are fixedly installed in the chimney 5, a clean smoke outlet 6.1 is opened on the side wall of the chimney 5, and a clean smoke inlet 6.2 is opened on the hood wall of the smoke hood 2. The clean smoke outlet 6.1 is connected to the clean smoke inlet 6.2 through a clean smoke pipe 6, a clean smoke valve 8 and a clean smoke circulation fan 7. The clean smoke valve 8, the clean smoke circulation fan 7, the oxygen content tester 10, and the nitrogen oxide content tester 11 are all electrically connected to the PLC controller 9.

[0021] In order to increase the uniformity of clean smoke distribution, the clean smoke inlet 6.2 is arranged on the top wall of the smoke hood 2, and the clean smoke inlet 6.2 is fixedly connected to a furnace inlet nozzle 12.

[0022] Instructions for use: When using the semi-enclosed ore-fired furnace flue gas treatment system of this embodiment, the flue gas treatment system of the original ore-fired furnace is modified. First, a clean flue gas outlet 6.1 is opened on the side wall of the chimney 5, a clean flue gas inlet 6.2 is opened on the top wall of the smoke hood 2, and an oxygen content tester 10 and a nitrogen oxide content tester 11 are set in the chimney 5. Then, the clean flue gas inlet 6.2 and the clean flue gas outlet 6.1 are connected through the clean flue gas pipeline 6, the clean flue gas valve 8 and the clean flue gas circulation fan 7 respectively. After the modification is completed, the system is put into use, and the initial nitrogen oxide generation in the ore-fired furnace is controlled by controlling the oxygen content entering the furnace body 1 of the ore-fired furnace. Specifically, the control process is as follows:

[0023] First, the ideal oxygen content and nitrogen oxide content of the clean flue gas are preset in the PLC controller 9, and then the oxygen content in the chimney 5 is monitored by the oxygen content monitoring oxygen content tester 10, and the nitrogen oxide content in the chimney 5 is monitored by the nitrogen oxide content tester 11, and the monitoring results are sent to the PLC controller 9. When the oxygen content and nitrogen oxide content in the clean flue gas are monitored to be higher than the preset value, the PLC controller 9 controls the clean flue gas valve 8 to increase the opening, and controls the clean flue gas circulation fan 7 to increase the frequency, so as to increase the clean flue gas content entering the submerged arc furnace, reduce the air content entering the submerged arc furnace, and reduce the initial nitrogen oxide generation in the submerged arc furnace body 1. When the oxygen content and nitrogen oxide content in the flue gas are monitored to meet the preset value, the valve 8 opening and the clean flue gas circulation fan 7 frequency are kept unchanged.

[0024] During this process, the clean flue gas entering the submerged arc furnace effectively increases the material surface temperature and accelerates the reaction rate in the submerged arc furnace.

[0025] Embodiment 2:

[0026] The overall structure of this embodiment is the same as that of embodiment 1, except that Figure 2 As shown, it also includes a waste heat boiler 13 ; specifically, the waste heat boiler 13 is arranged between the air outlet end of the smoke hood 2 and the air inlet end of the flue gas purification system 4 .

[0027] During the production process of the submerged arc furnace, the waste heat of the flue gas of the submerged arc furnace is recovered and utilized by the waste heat boiler 13 to improve the heat utilization rate of the flue gas.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A semi-enclosed submerged arc furnace flue gas treatment system, comprising a submerged arc furnace body, a smoke hood, a smoke duct, a smoke purification system, and a chimney; the smoke hood is arranged directly above the submerged arc furnace body, the gas outlet end of the smoke hood is connected to the gas inlet end of the smoke purification system through the smoke duct, and the gas outlet end of the smoke purification system is connected to the chimney; characterized in that: It also includes clean flue gas ducts, clean flue gas circulation fans, and clean flue gas valves; A clean smoke outlet is provided on the side wall of the chimney, and a clean smoke inlet is provided on the hood wall of the smoke hood. The clean smoke outlet is connected to the clean smoke inlet through the clean smoke pipe, the clean smoke valve and the clean smoke circulation fan.

2. A semi-enclosed submerged arc furnace flue gas treatment system according to claim 1, characterized in that: Also included is a furnace entry nozzle; The clean smoke inlet is arranged on the top wall of the smoke hood, and the air inlet end of the furnace inlet nozzle is fixedly connected and communicated with the clean smoke inlet.

3. A semi-enclosed submerged arc furnace flue gas treatment system according to claim 1, characterized in that: It also includes a PLC controller, a nitrogen oxide content tester, and an oxygen content tester; The oxygen content tester and the nitrogen oxide content tester are both fixedly arranged in the chimney; The clean flue gas valve, the clean flue gas circulation fan, the oxygen content tester, and the nitrogen oxide content tester are all electrically connected to the PLC controller.

4. A semi-enclosed submerged arc furnace flue gas treatment system according to any one of claims 1 to 3, characterized in that: It also includes a waste heat boiler; the waste heat boiler is arranged between the air outlet end of the smoke hood and the air inlet end of the smoke purification system.

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