Waste gas emission method of melting furnace

Abstract

The invention discloses a waste gas emission method for a melting furnace, and belongs to the technical field of waste gas emission of melting furnaces, the method comprises the following steps: waste gas generated by the melting furnace flows into a heat storage cavity; whether the waste gas after heat exchange flows into the waste gas conversion valve through a waste gas inlet of the waste gas conversion valve or not is judged, if yes, the controller detects whether the desulfurizing tower, the denitration tower and the dust remover work normally or not, and if at least one of the desulfurizing tower, the denitration tower and the dust remover breaks down, the waste gas inlet communicates with a first waste gas outlet of the waste gas conversion valve, and the waste gas outlet communicates with a second waste gas outlet of the waste gas conversion valve; if the desulfurization tower, the denitration tower and the dust remover work normally, the waste gas outlet is communicated with a second waste gas outlet of the waste gas conversion valve, the waste gas flows out of the second waste gas outlet, and the waste gas is subjected to desulfurization by the desulfurization tower, denitration by the denitration tower and dust removal by the dust remover in sequence and then flows into the heat storage cavity; and the gas is discharged into the atmospheric environment from the chimney. The device can be used for waste gas emission of the melting furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of exhaust gas emission from melting furnaces, and in particular relates to an exhaust gas emission method from melting furnaces. Background Art

[0002] A melting furnace refers to a thermal equipment used to melt glass batch materials in glass manufacturing. A large amount of waste gas is generated during the melting process, which contains dust and NO. x , SO2, etc. From the perspective of environmental protection, the waste gas needs to be post-treated with desulfurization, denitrification and dust removal.

[0003] However, in actual applications, once the above-mentioned post-processing equipment fails, the entire production line of the melting furnace will be shut down, affecting the production efficiency of the melting furnace. Summary of the invention

[0004] In view of the above analysis, the present invention aims to provide a waste gas emission method for a melting furnace, so as to solve the problem in the prior art that a failure of post-processing equipment causes the entire production line of the melting furnace to stop, thereby affecting the production efficiency of the melting furnace.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions.

[0006] The present invention provides a method for exhaust gas from a melting furnace, comprising the following steps:

[0007] Step a: the exhaust gas generated by the melting furnace flows into the heat storage chamber, exchanges heat with the natural gas in the heating pipeline of the melting furnace through the side wall of the heat storage chamber, and preheats the natural gas in the heating pipeline;

[0008] Step b: Determine whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve. If so, the controller detects whether the desulfurization tower, the denitrification tower and the dust collector are working normally. If at least one of the desulfurization tower, the denitrification tower and the dust collector fails, proceed to step c. If the desulfurization tower, the denitrification tower and the dust collector are all working normally, proceed to step d.

[0009] Step c: the exhaust gas inlet is connected to the first exhaust gas outlet of the exhaust gas conversion valve, and the exhaust gas flows out from the first exhaust gas outlet and circulates into the heat storage chamber;

[0010] Step d: the exhaust gas outlet is connected to the second exhaust gas outlet of the exhaust gas conversion valve, the exhaust gas flows out from the second exhaust gas outlet, passes through the desulfurization tower for desulfurization, the denitrification tower for denitrification and the dust collector for dust removal in sequence, and is discharged into the atmosphere from the chimney.

[0011] Further, judging whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve comprises the following steps:

[0012] Collect the exhaust gas concentration value in the exhaust gas conversion valve and determine whether the exhaust gas concentration value exceeds the concentration threshold;

[0013] If the exhaust gas concentration value is above the concentration threshold, it means that the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve;

[0014] If the exhaust gas concentration value is lower than the concentration threshold, it means that the exhaust gas after heat exchange does not flow into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve.

[0015] Furthermore, before step a, the method further includes the following steps:

[0016] Start the melting furnace and conduct a test run of the melting furnace.

[0017] Furthermore, the following steps are further included after the furnace is tested:

[0018] The airflow generated by the melting furnace during the commissioning phase is discharged directly into the atmosphere through the chimney.

[0019] Furthermore, in step d, the desulfurization temperature is 480-550°C.

[0020] Furthermore, in step d, the denitration temperature is 400-450°C.

[0021] Furthermore, in step d, the dust removal temperature is 350-380°C.

[0022] Furthermore, the exhaust gas temperature generated by the melting furnace is 500-600°C.

[0023] Furthermore, the exhaust gas emission of the melting furnace is 80,000 to 110,000 m3 / h.

[0024] Further, the exhaust gas discharge method of the melting furnace is applicable to the melting furnace equipment.

[0025] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0026] A) The exhaust gas emission method of the melting furnace provided by the present invention performs fault detection on the desulfurization tower, denitrification tower and dust collector during the exhaust gas emission process before the exhaust gas is discharged to the desulfurization tower, and controls the specific flow path of the exhaust gas through the exhaust gas conversion valve. If the desulfurization tower, denitrification tower and dust collector are working normally, the melting furnace is in normal exhaust mode, and the exhaust gas can be subsequently processed normally. If one of the desulfurization tower, denitrification tower and dust collector fails, the melting furnace is in emergency emission mode, and the exhaust gas can be circulated to the heat storage chamber for circulation, so as to avoid the exhaust gas that has not been desulfurized, denitrified and dusted being directly discharged into the atmosphere to pollute the environment.

[0027] B) The exhaust gas emission method of the melting furnace provided by the present invention is that once one of the desulfurization tower, denitrification tower and dust collector fails, the operator will promptly repair the corresponding equipment. Therefore, the circulation time of the exhaust gas in the heat storage chamber will not be too long, thereby ensuring the normal operation of the entire production line of the melting furnace and effectively improving the production efficiency of the melting furnace.

[0028] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0030] Figure 1 A flow chart of a method for exhaust gas emission from a melting furnace provided in Embodiment 1 of the present invention;

[0031] Figure 2 A schematic diagram of the structure of a melting furnace device in a method for exhaust gas discharge from a melting furnace provided in Embodiment 1 of the present invention;

[0032] Figure 3 A schematic structural diagram of a heat exchange unit in a waste gas discharge method of a melting furnace provided in Embodiment 1 of the present invention;

[0033] Figure 4 A schematic diagram of the structure of a dust removal and smoke exhaust pipeline in a waste gas emission method of a melting furnace provided in Embodiment 1 of the present invention, wherein the thermal expansion protrusion is not in contact with the contact sensor;

[0034] Figure 5 This is a schematic structural diagram of a dust removal and smoke exhaust pipeline in a waste gas emission method of a melting furnace provided in Example 1 of the present invention, wherein the thermal expansion protrusion contacts with a contact sensor.

[0035] Reference numerals:

[0036] 1-chimney; 2-dust removal and smoke exhaust pipeline; 201-contact sensor; 202-exhaust gas circulation inner pipe; 203-temperature control outer pipe; 204-thermal expansion protrusion; 3-melting furnace; 4-heat storage chamber; 5-underground horizontal flue; 6-transition vertical flue; 7-ground horizontal flue; 8-flue control valve; 9-desulfurization tower; 10-dust collector; 11-liquid storage tank; 12-coolant converter; 13-high-temperature exhaust gas inlet; 14-low-temperature exhaust gas inlet; 15-low-temperature exhaust gas outlet; 16-exhaust gas partition; 17-connecting converter; 18-cooling chamber; 19-heat exchange tank body; 20-coolant tank body; 21-temperature acquisition tester; 22-regulating three-way valve; 23-denitrification tower. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0038] Embodiment 1

[0039] This embodiment provides a method for exhaust gas discharge from a melting furnace, see Figure 1 , including the following steps:

[0040] Step a: The exhaust gas generated by the melting furnace 3 flows into the heat storage chamber 4, and exchanges heat with the natural gas in the heating pipeline of the melting furnace 3 through the side wall of the heat storage chamber to preheat the natural gas in the heating pipeline. The exhaust gas temperature generated by the melting furnace 3 is 500-600°C, and the exhaust gas emission of the melting furnace 3 is 80,000-110,000 m 3 / h (for example, 100,000 m 3 / h);

[0041] Step b: Determine whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve. If so, the controller detects whether the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 are working normally. If at least one of the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 fails, proceed to step c. If the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 are all working normally, proceed to step d.

[0042] Step c: the exhaust gas inlet is connected to the first exhaust gas outlet of the exhaust gas conversion valve, and the exhaust gas flows out from the first exhaust gas outlet and circulates into the heat storage chamber 4;

[0043] Step d: the exhaust gas outlet is connected to the second exhaust gas outlet of the exhaust gas conversion valve, the exhaust gas flows out from the second exhaust gas outlet, passes through the desulfurization tower 9 for desulfurization, the denitrification tower 23 for denitrification and the dust collector 10 for dust removal, and then is discharged from the chimney 1 into the atmosphere.

[0044] Compared with the prior art, the exhaust gas emission method of the melting furnace 3 provided in the present embodiment performs fault detection on the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 during the exhaust gas emission process before the exhaust gas is discharged to the desulfurization tower 9, and controls the specific flow path of the exhaust gas through the exhaust gas conversion valve. If the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 are working normally, the melting furnace 3 is in a normal exhaust mode, and the exhaust gas can be subsequently processed normally. If one of the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 fails, the melting furnace 3 is in an emergency emission mode, and the exhaust gas can be circulated to the heat storage chamber 4 for circulation, so as to avoid the exhaust gas that has not been desulfurized, denitrified and dust-removed being directly discharged into the atmosphere to pollute the environment.

[0045] It should be noted that once one of the desulfurization tower 9, the denitrification tower 23 and the dust collector 10 fails, the operator will promptly carry out maintenance on the corresponding equipment. Therefore, the circulation time of the exhaust gas in the heat storage chamber 4 will not be too long, thereby ensuring the normal operation of the entire production line of the melting furnace 3 and effectively improving the production efficiency of the melting furnace 3.

[0046] Exemplarily, the above-mentioned determination of whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve comprises the following steps:

[0047] Collect the exhaust gas concentration value in the exhaust gas conversion valve and determine whether the exhaust gas concentration value exceeds the concentration threshold;

[0048] If the exhaust gas concentration value is above the concentration threshold, it means that the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve;

[0049] If the exhaust gas concentration value is lower than the concentration threshold, it means that the exhaust gas after heat exchange does not flow into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve.

[0050] Considering that during the trial operation of the melting furnace 3, it is not necessary to perform heat exchange or desulfurization, denitrification and dust removal in the heat storage chamber 4, therefore, the following steps are also included before the above step a:

[0051] Start the melting furnace 3 and conduct a test run on the melting furnace 3;

[0052] The airflow generated by the melting furnace 3 during the commissioning phase is directly discharged into the atmosphere through the chimney 1 .

[0053] In order to ensure the desulfurization effect, illustratively, in the above step d, the desulfurization temperature is 480-550°C.

[0054] In order to ensure the denitration effect, illustratively, in the above step d, the denitration temperature is 400-450°C.

[0055] Similarly, in order to ensure the dust removal effect, illustratively, in the above step d, the dust removal temperature is 350-380°C.

[0056] Exemplarily, the above-mentioned method for exhausting waste gas from a melting furnace adopts a melting furnace device having the following structure:

[0057] See also Figure 2 The above-mentioned melting furnace equipment includes a melting furnace 3, a heat storage chamber 4, a desulfurization tower 9, a denitrification tower 23, a dust collector 10 and a chimney 1 which are connected in sequence along the exhaust gas direction, wherein the heat storage chamber 4 is arranged on the outer wall of the melting furnace 3 and is located at the kiln head of the melting furnace 3, the exhaust gas outlet of the melting furnace 3 is connected to the exhaust gas inlet of the heat storage chamber 4, and the exhaust gas outlet of the heat storage chamber 4 is connected to the chimney 1 through the desulfurization tower 9, the denitrification tower 23, the dust collector 10 and the induced draft fan in sequence.

[0058] Exemplarily, there is one chimney 1, and there are multiple melting furnaces 3 and heat storage chambers 4, and the melting furnaces 3 correspond to the heat storage chambers 4 one by one, and one chimney 1 corresponds to multiple melting furnaces 3. In this way, on the one hand, the chimneys 1 of multiple glass furnace production lines are merged into one, and the exhaust gas outlets of multiple glass furnaces are connected to one chimney 1. One chimney 1 is used to realize the exhaust gas discharge of multiple glass furnaces, and the number of chimneys 1 is optimized, which can not only greatly reduce the engineering cost of glass melting, but also effectively reduce the overall footprint of the equipment. On the other hand, by setting the heat storage chamber 4, the heat storage chamber 4 is arranged on the outer wall of the melting furnace 3 and located at the kiln head position of the melting furnace 3. The high-temperature exhaust gas generated by the melting furnace 3 can be circulated to the heat storage chamber 4, and the glass at the kiln head position of the melting furnace 3 is preheated, thereby improving the waste heat utilization rate of the above-mentioned melting furnace equipment.

[0059] Exemplarily, the above-mentioned melting furnace equipment also includes an underground horizontal flue 5, a transition vertical flue 6 and a ground horizontal flue 7 which are connected in sequence from the melting furnace 3 to the chimney 1, and the exhaust gas outlet of the heat storage chamber 4 is connected in sequence through the underground horizontal flue 5, the transition vertical flue 6 and the ground horizontal flue 7, and the heat storage chamber 4 corresponds one-to-one to the underground horizontal flue 5, the transition vertical flue 6 and the ground horizontal flue 7.

[0060] In order to achieve connection or disconnection between each heat storage chamber 4 and the chimney 1, a flue control valve 8 is provided on the underground horizontal flue 5, which controls the connection or disconnection of the underground horizontal flue 5 through the flue plate gate, thereby controlling the connection or disconnection of the heat storage chamber 4 and the chimney 1.

[0061] It is worth noting that since the dust collector 10 requires a relatively low temperature of the exhaust gas, if the exhaust gas temperature is relatively high, it may cause damage to the components in the dust collector 10. In order to ensure that the temperature of the exhaust gas discharged from the denitrification tower 23 is maintained within an appropriate range, the above-mentioned melting furnace equipment also includes a heat exchange unit arranged between the denitrification tower 23 and the dust collector 10, and the temperature of the exhaust gas is regulated by the heat exchange unit.

[0062] Specifically, for the structure of the heat exchange unit, see Figure 3 , which includes a cooling chamber 18, a heat exchange tank body 19, a coolant tank body 20, a temperature collection tester 21, a control three-way valve 22 and a connecting converter 17, the control three-way valve 22 has a control air inlet, a first control air outlet and a second control air outlet, the cooling chamber 18 has a high-temperature exhaust gas inlet 13, a low-temperature exhaust gas inlet 14 and a low-temperature exhaust gas outlet 15, the high-temperature exhaust gas inlet 13 is connected to the exhaust gas outlet of the denitration tower 23, the low-temperature exhaust gas outlet 15 is connected to the control air inlet, and the first control air outlet is connected to the The exhaust gas inlet of the dust collector 10 is connected, the second regulating outlet is connected to the exhaust gas inlet of the heat exchange tank body 19, the exhaust gas outlet of the heat exchange tank body 19 is connected to the low-temperature exhaust gas inlet 14, the temperature collection tester 21 is arranged at the low-temperature exhaust gas outlet 15, the liquid outlet of the coolant tank body 20 is connected to the medium liquid inlet of the heat exchange tank body 19, the medium liquid outlet of the heat exchange tank body 19 is connected to the liquid inlet of the coolant tank body 20, and the connecting converter 17 is respectively connected to the temperature collection tester 21 and the regulating three-way valve 22.

[0063] During implementation, the temperature acquisition tester 21 detects the temperature data of the exhaust gas at the low-temperature exhaust gas outlet 15 in real time and transmits it to the connecting converter 17. The connecting converter 17 receives the temperature data and determines whether the temperature data is higher than the threshold temperature. If it is higher than the threshold temperature, it means that the temperature of the exhaust gas at the low-temperature exhaust gas outlet 15 is too high and is not suitable for subsequent dust removal treatment. Then the connecting converter 17 controls the regulating air inlet to be connected with the second regulating air outlet, and the exhaust gas discharged from the cooling chamber 18 enters the heat exchange tank 19 for further cooling. After cooling, it is discharged into the cooling chamber 18 and mixed with the exhaust gas in the cooling chamber 18 to cool the exhaust gas in the cooling chamber 18. If it is lower than or equal to the threshold temperature, it means that the temperature of the exhaust gas at the low-temperature exhaust gas outlet 15 is suitable and subsequent dust removal treatment can be carried out. Then the connecting converter 17 controls the regulating air inlet to be connected with the first regulating air outlet, and the exhaust gas is directly discharged into the dust collector 10 for dust removal treatment.

[0064] Exemplarily, the cooling chamber 18 is cylindrical in shape, and the feeding direction of the high-temperature exhaust gas inlet 13 and the feeding direction of the low-temperature feed port 14 are both along the tangential direction of the cooling chamber 18, and the feeding directions of the two are rotated by a certain angle in a clockwise or counterclockwise direction, so that the cyclone direction of the exhaust gas flowing from the high-temperature exhaust gas inlet 13 into the cooling chamber 18 is the same as the cyclone direction of the exhaust gas flowing from the low-temperature feed port 14 into the cooling chamber 18, and the cyclone of the exhaust gas is utilized to achieve uniform mixing of the exhaust gases of two temperatures without the need for additional disturbance parts, thereby effectively simplifying the structure.

[0065] Considering that the temperature range required for subsequent chimney 1 emissions is lower than the temperature range required for the dust collector 10 , in order to further cool the exhaust gas discharged from the dust collector 10 , the above-mentioned melting furnace equipment also includes a dust removal and smoke exhaust pipeline 2 , a liquid storage tank 11 and a coolant converter 12 .

[0066] Specifically, the dust removal and smoke exhaust pipeline 2 includes an inner exhaust gas circulation tube 202 and a temperature-regulating outer tube 203 which is sleeved on the outside of the inner exhaust gas circulation tube 202. There is a gap between the inner exhaust gas circulation tube 202 and the temperature-regulating outer tube 203, and the gap serves as a temperature-regulating interlayer, which is connected to the liquid storage tank 11. The outer wall of the inner exhaust gas circulation tube 202 is provided with a thermal expansion protrusion 204, and the inner wall of the temperature-regulating outer tube 203 is provided with a contact sensor 201. The thermal expansion protrusion 204 corresponds to the position of the contact sensor 201, and there is a tiny gap between the top of the thermal expansion protrusion 204 and the contact sensor 201. The coolant converter 12 is connected to the contact sensor 201 and the liquid storage tank 11.

[0067] On the one hand, when the exhaust gas temperature in the dust removal and smoke exhaust pipeline 2 does not exceed the temperature threshold, there is a small gap between the outer ring surface of the thermal expansion protrusion 204 and the contact sensor 201, and the exhaust gas flow inner tube 202 and the temperature regulating outer tube 203 are isolated from the air, so that the temperature regulating interlayer can form air insulation, see Figure 4 .

[0068] On the other hand, when the exhaust gas temperature in the dust removal and smoke exhaust pipeline 2 exceeds the temperature threshold, the heat in the exhaust gas will be transferred to the thermal expansion protrusion 204, so that the thickness of the thermal expansion protrusion 204 increases, and the top of the thermal expansion protrusion 204 contacts the contact sensor 201. The contact sensor 201 sends an over-temperature signal to the coolant converter 12. The coolant converter 12 controls the liquid storage tank 11 to pass the coolant into the temperature regulating interlayer. The temperature regulating interlayer can directly cool the exhaust gas through the exhaust gas circulation inner tube 202. See Figure 5 .

[0069] On the other hand, when the exhaust gas temperature in the dust removal and smoke exhaust pipeline 2 exceeds the temperature threshold, the thermal expansion protrusions 204 and the contact sensor 201 that are in contact with each other can also serve as a heat-conducting structure, so that the heat in the exhaust gas can diffuse into the external environment, thereby further improving the cooling effect of the exhaust gas.

[0070] Considering that one chimney 1 needs to correspond to multiple melting furnace 3 production lines, the temperature and composition of high-temperature exhaust gas generated by different melting furnaces 3 are different, and the directions of high-temperature exhaust gas discharged into the chimney 1 are also different. In order to avoid the confusion of multiple high-temperature exhaust gases, the above-mentioned melting furnace equipment also includes an exhaust gas baffle 16 arranged in the chimney 1. The exhaust gas baffle 16 is arranged along the axial direction of the chimney 1. Figure 2 .

[0071] Exemplarily, the height of the exhaust gas baffle 16 is lower than the height of the chimney 1. Accordingly, the chimney 1 is divided into a smoke isolation chamber provided with the exhaust gas baffle 16 and a mixed smoke chamber located above the smoke isolation chamber. The smoke isolation chamber divides the exhaust gas baffle 16 into a plurality of smoke exhaust sub-chambers, and the smoke exhaust sub-chambers correspond to the melting furnace 3 one by one. In this way, on the one hand, the chimney 1 with this special structure can divide the lower half of the chimney 1 into a plurality of smoke exhaust sub-chambers through the setting of the exhaust gas baffle 16. Each smoke exhaust sub-chamber is specifically used for exhausting smoke from a melting furnace 3, thereby avoiding the confusion of multiple high-temperature exhaust gases and ensuring the smoothness of smoke exhaust. On the other hand, the setting of the exhaust gas baffle 16 will inevitably increase the exhaust gas flow resistance in the chimney 1. After being guided by a plurality of smoke exhaust sub-chambers, the exhaust gas basically flows upward in the vertical direction. The exhaust gas baffle 16 is no longer set in the mixed smoke chamber, which can further reduce the influence of the setting of the exhaust gas baffle 16 on the exhaust gas flow resistance in the chimney 1.

[0072] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for exhaust gas from a melting furnace, characterized in that: The steps include: Step a: the exhaust gas generated by the melting furnace flows into the heat storage chamber, exchanges heat with the natural gas in the heating pipeline of the melting furnace through the side wall of the heat storage chamber, and preheats the natural gas in the heating pipeline; Step b: Determine whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve. If so, the controller detects whether the desulfurization tower, the denitrification tower and the dust collector are working normally. If at least one of the desulfurization tower, the denitrification tower and the dust collector fails, proceed to step c. If the desulfurization tower, the denitrification tower and the dust collector are all working normally, proceed to step d. Step c: the exhaust gas inlet is connected to the first exhaust gas outlet of the exhaust gas conversion valve, and the exhaust gas flows out from the first exhaust gas outlet and circulates into the heat storage chamber; Step d: the exhaust gas outlet is connected to the second exhaust gas outlet of the exhaust gas conversion valve, the exhaust gas flows out from the second exhaust gas outlet, passes through the desulfurization tower for desulfurization, the denitrification tower for denitrification and the dust collector for dust removal in sequence, and is discharged into the atmosphere from the chimney.

2. The method for exhaust gas from a melting furnace according to claim 1, characterized in that: The step of judging whether the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve comprises the following steps: Collect the exhaust gas concentration value in the exhaust gas conversion valve and determine whether the exhaust gas concentration value exceeds the concentration threshold; If the exhaust gas concentration value is above the concentration threshold, it means that the exhaust gas after heat exchange flows into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve; If the exhaust gas concentration value is lower than the concentration threshold, it means that the exhaust gas after heat exchange does not flow into the exhaust gas conversion valve through the exhaust gas inlet of the exhaust gas conversion valve.

3. The method for exhaust gas from a melting furnace according to claim 1, characterized in that: The step a also includes the following steps: Start the melting furnace and conduct a test run of the melting furnace.

4. The method for exhaust gas discharge from a melting furnace according to claim 3, characterized in that: The trial operation of the melting furnace further comprises the following steps: The airflow generated by the melting furnace during the commissioning phase is directly discharged into the atmosphere through a chimney.

5. The exhaust gas discharge method of a melting furnace according to claim 1, characterized in that: In the step d, the desulfurization temperature is 480-550°C.

6. The method for exhaust gas discharge from a melting furnace according to claim 1, characterized in that: In the step d, the denitration temperature is 400-450°C.

7. The exhaust gas discharge method of a melting furnace according to claim 1, characterized in that: In the step d, the dust removal temperature is 350-380°C.

8. The method for exhaust gas discharge from a melting furnace according to claim 1, characterized in that: The exhaust gas temperature generated by the melting furnace is 500-600°C.

9. The method for exhaust gas discharge from a melting furnace according to claim 1, characterized in that: The exhaust gas emission of the melting furnace is 80,000 to 110,000 m 3 / h.

10. The method for exhaust gas discharge from a melting furnace according to claim 1, characterized in that: The waste gas discharge method of the melting furnace is applicable to melting furnace equipment.

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