A furnace zone isolation device control method

Abstract

The application discloses a furnace area isolation device control method, comprising the following steps: isolating the atmosphere of the slow cooling section of the strip steel annealing furnace and the atmosphere of the fast cooling section through the furnace area isolation device; adjusting the input amount of nitrogen-hydrogen mixed gas HN and nitrogen N2 input into the slow cooling section, and adjusting the input amount of nitrogen N2 input into the fast cooling section, realizing the set furnace pressure sequence, and ensuring that the furnace pressure of the fast cooling section is greater than the furnace pressure of the slow cooling section. The atmosphere of the slow cooling section and the fast cooling section can be more effectively isolated, the processing quality of the processing line to products is improved, the product quality is greatly improved, the cost is low, the unit is expanded to products, and the economy is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of continuous annealing heat treatment, in particular to a furnace area isolation device control method. BACKGROUND

[0002] Generally, a mechanical sealing door is designed between the slow cooling section and the fast cooling section. The main function of the sealing door is to establish furnace pressure gradient, and it cannot completely isolate the atmosphere of the slow cooling section and the fast cooling section. In order to realize high content of the slow cooling section and low content of the fast cooling section, an isolation device is urgently needed to more effectively isolate the atmosphere of the slow cooling section and the fast cooling section. SUMMARY

[0003] The present application solves the technical problems of the prior art, and provides a furnace area isolation device control method, which can more effectively isolate the atmosphere of the slow cooling section and the fast cooling section, improve the processing quality of the processing line to the product, greatly improve the product quality, has low cost, improves the expansion of the unit product, and has good economy.

[0004] The technical scheme adopted by the present application to solve the above technical problems is:

[0005] A furnace area isolation device control method, comprising the following steps: isolating the atmosphere of the slow cooling section and the atmosphere of the fast cooling section of the strip annealing furnace through the furnace area isolation device; adjusting the input amount of nitrogen-hydrogen mixed gas HN and nitrogen N2 input into the slow cooling section, and adjusting the input amount of nitrogen N2 input into the fast cooling section, to realize the set furnace pressure sequence and ensure that the fast cooling section furnace pressure P6 is greater than the slow cooling section furnace pressure P2.

[0006] According to the above technical scheme, in the production process, the furnace area isolation device control method further comprises that the furnace pressure of the slow cooling section and the furnace pressure of the fast cooling section are connected with high-pressure nitrogen, and the specific process is as follows: when the fast cooling section furnace pressure P6 is lower than the safety set value or the hydrogen content of the fast cooling section is greater than 2%, the high-pressure nitrogen input of the fast cooling section is opened, so that the fast cooling section furnace pressure P6 returns to the safety set value and the hydrogen content of the fast cooling section is not greater than 2%, to maintain safe production;

[0007] When the slow cooling section furnace pressure P2 is lower than the safety set value, the high-pressure nitrogen input of the slow cooling section is opened to maintain safe production, and after the slow cooling section furnace pressure P2 reaches the set value again, the high-pressure nitrogen is closed, while ensuring P6>P2 to prevent the slow cooling section atmosphere from diffusing into the fast cooling section.

[0008] According to the above technical scheme, the furnace area isolation device comprises a shell and two sealing plates and a controller, the shell is arranged between the slow cooling section and the fast cooling section, the two sealing plates are arranged at the inlet end and the outlet end of the shell at both ends of the shell, the two sealing plates are both connected with a lifting mechanism, and the controller is connected with the lifting mechanism through a frequency converter.

[0009] According to the technical scheme, the lifting mechanism comprises a worm wheel, a worm and a motor, the upper end of the sealing plate is connected with the worm, and the worm wheel is engaged with the worm.

[0010] According to the technical scheme, the upper end of the shell is provided with a diffusion passage, the diffusion passage is arranged between the two sealing plates, and a pressure regulating valve is arranged on the diffusion passage.

[0011] According to the technical scheme, the diffusion passage port pressure P4 of the furnace area isolation device is interlocked with the automatic regulating valve on the diffusion passage, and the furnace pressure at the P4 point is kept at a set value.

[0012] The pressure P5 at the inlet of the fast cooling section is slightly greater than the pressure P3 at the outlet of the slow cooling section, and the pressure P3 at the outlet of the slow cooling section is greater than the diffusion passage port pressure P4 of the furnace area isolation device.

[0013] According to the technical scheme, the pressure regulating valve comprises a manual butterfly valve and a ring slit adjusting device, the manual butterfly valve is arranged on the diffusion passage, the ring slit adjusting device comprises a telescopic cylinder, the two ends of the telescopic cylinder are hingedly connected with the manual butterfly valve and the upper end of the shell respectively, and a connecting rod is connected between the telescopic cylinder and the manual butterfly valve.

[0014] According to the technical scheme, the furnace area isolation device further comprises a circulating spraying cooling device, and the circulating spraying cooling device is connected with the inner cavity of the shell.

[0015] According to the technical scheme, the HN mixed gas main pipe and the nitrogen gas pipeline are connected to the slow cooling section and the fast cooling section, and a set of hydrogen and oxygen detection instruments are arranged in the slow cooling section and the fast cooling section.

[0016] According to the technical scheme, when the process requires that the fast cooling section contains H2 and the slow cooling section does not contain H2, the HN mixed gas pipeline from the nitrogen hydrogen mixer to the slow cooling section is closed; at this time, the nitrogen gas in the slow cooling section can only be sent into the furnace through one side of the furnace body.

[0017] The present application has the following beneficial effects:

[0018] The method can more effectively isolate the atmospheres of the slow cooling section and the fast cooling section, improve the processing quality of the processing line to the products, greatly improve the product quality, the cost is low, the product expansion of the unit is improved, the economy is better, and most importantly, the flexibility of the unit is greatly improved; therefore, the furnace area isolation device has good popularization prospect and large practicality, the equipment can be delivered to the site in one time in the factory, and the installation is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic diagram of the furnace pressure distribution in the annealing furnace after the furnace area isolation device control method is adopted in the embodiment of the present application;

[0020] Figure 2 is a control principle schematic diagram of the furnace area isolation device in the embodiment of the present application.

[0021] Figure 3 is a structural schematic diagram of the furnace zone isolation device in the embodiment of the present application;

[0022] Figure 4 is Figure 3 a C-C cross-sectional view of

[0023] In the figure, 1 - upper cover, 2 - shell, 3 - diffusion channel, 4 - lifting mechanism, 5 - sealing plate, 6 - frame base, 7 - manual butterfly valve, 8 - ring gap adjusting device, 9 - labyrinth channel, 10 - motor, 11 - frequency converter, 12 - first field bus, 13 - controller, 14 - connection position encoder cable. DETAILED DESCRIPTION

[0024] The present application will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] Referring to Figures 1-2 , an embodiment 1 of the furnace zone isolation device control method provided by the present application includes the following steps: completely isolating the atmosphere of the slow cooling section of the strip annealing furnace and the atmosphere of the fast cooling section by the furnace zone isolation device; the atmosphere of the slow cooling section of the strip annealing furnace is connected to the atmosphere of the strip annealing furnace for joint regulation and control, and the fast cooling section of the strip annealing furnace is controlled separately; the amount of nitrogen-hydrogen mixed gas HN and nitrogen N2 introduced into the slow cooling section is adjusted, and the amount of nitrogen N2 and / or nitrogen-hydrogen mixed gas HN introduced into the fast cooling section is adjusted to achieve a set furnace pressure sequence value, so as to ensure that the furnace pressure P6 of the fast cooling section is slightly greater than the furnace pressure P2 of the slow cooling section; the fast cooling section is approximately a sealed box, and the furnace pressure is controlled by introducing a normal amount of N2. In order to prevent the atmosphere in the slow cooling section from diffusing into the fast cooling section, the pressure P5 at the inlet of the fast cooling section is controlled to be slightly greater than the pressure P3 at the outlet of the slow cooling section.

[0026] Further, after the above steps, in the production process, the furnace zone isolation device control method further includes that the furnace pressures of the slow cooling section and the fast cooling section are both interlocked with high-pressure nitrogen, and the specific process is as follows: when the furnace pressure P6 of the fast cooling section is lower than a safety set value or P5 < P3 or the hydrogen content in the fast cooling section is greater than 2%, the high-pressure nitrogen introduced into the fast cooling section is automatically opened, so that the furnace pressure P6 of the fast cooling section returns to the safety set value and the hydrogen content in the fast cooling section is not greater than 2%, thereby maintaining safe production;

[0027] When the furnace pressure P2 of the slow cooling section is lower than a safety set value, the high-pressure nitrogen introduced into the slow cooling section is automatically opened to maintain safe production, and after the furnace pressure P2 of the slow cooling section returns to the set value, the high-pressure nitrogen is closed, while ensuring that P6 > P2 to prevent the atmosphere in the slow cooling section from diffusing into the fast cooling section.

[0028] Embodiment 2

[0029] As Figures 3-4As shown, on the basis of embodiment 1, further increase the furnace zone isolation device technical feature limit, the performance of the limited embodiment 2 is more excellent.

[0030] The furnace zone isolation device comprises a housing 2 and two sealing plates 5 and a controller 13, the housing 2 is arranged between the slow cooling section and the fast cooling section, the inlet and outlet of the housing 2 are respectively connected with the outlet of the slow cooling section and the inlet of the fast cooling section, the two sealing plates 5 are arranged at the inlet end and the outlet end of the housing 2 respectively, the two sealing plates 5 are connected with lifting mechanisms 4, and the controller 13 is connected with the lifting mechanisms 4 through a frequency converter 11; the complete set is debugged before leaving the factory, the reconstruction project is convenient and has small engineering quantity, the new project can be directly designed according to the design, the investment is small, and the economic benefit is good.

[0031] Embodiment 3

[0032] On the basis of embodiments 1 and 2, further increase the specific technical feature limit of the lifting mechanism, and the performance of the limited embodiment 3 is more excellent.

[0033] Further, the lifting mechanism 4 comprises a worm gear, a worm and a motor 10, the upper end of the sealing plate 5 is connected with the worm, the worm gear is engaged with the worm, the motor 10 is connected with the controller 13 through the frequency converter 11 through the first field bus 12, and an encoder is arranged on the worm or the motor 10, and the encoder is connected with the controller 13.

[0034] Further, the housing 2 is provided with a diffusion channel 3, the diffusion channel 3 is arranged between the two sealing plates 5, and the diffusion channel 3 is provided with a pressure regulating valve.

[0035] Further, the diffusion channel port pressure P4 of the furnace zone isolation device is interlocked with the automatic regulating valve on the diffusion channel 3, and the P4 point furnace pressure is kept at a set value;

[0036] The pressure P5 at the inlet of the fast cooling section is slightly greater than the pressure P3 at the outlet of the slow cooling section, in order to prevent the atmosphere in the slow cooling section from diffusing to the fast cooling section, the pressure P3 at the outlet of the slow cooling section is greater than the diffusion channel port pressure P4 of the furnace zone isolation device.

[0037] Further, the set value of P4 ensures that there is a suitable pressure difference value between P4 and P3 / P5; if the pressure difference value is too small, the isolation effect is not good; if the pressure difference value is too large, the diffusion amount of the protective gas will be too large, and the consumption of the protective gas will be too large; the suitable P4 value standard is that the hydrogen content in the fast cooling section is below 1-2% on the basis of meeting the furnace pressure sequence value.

[0038] Further, the pressure regulating valve comprises a manual butterfly valve 7 and a ring slit adjusting device 8, the manual butterfly valve 7 is arranged on the diffusion channel 3, the ring slit adjusting device 8 comprises a telescopic cylinder, the two ends of the telescopic cylinder are respectively hinged to the manual butterfly valve 7 and the upper end of the housing 2, and a connecting rod is connected between the telescopic cylinder and the manual butterfly valve 7, Figure 3The pressure regulating valve is not given in the prior art.

[0039] The telescopic cylinder is an oil cylinder, an electric cylinder or a gas cylinder.

[0040] Further, the isolation device uses an adjustable pressure baffle to isolate the atmosphere between the slow cooling section and the rapid cooling section, and uses a worm and gear device electric actuator to realize the micro adjustment of the baffle stroke; an exhaust passage is arranged in the middle to adjust the furnace pressure, a manual butterfly valve 7 and a ring seam adjusting device 8 are used to participate in the furnace pressure control, and an ignition electrode is used for ignition to ignite the overflow combustible gas.

[0041] Further, the furnace zone isolation device further comprises a circulating jet cooling device connected with the inner cavity of the shell 2.

[0042] Further, two air cooling devices (AJC) are arranged on the circulating jet cooling device (RJC).

[0043] Further, the first section of the rapid cooling section (RGJCS) is removed as a whole, and the first section of the rapid cooling section (including the shell, the fan and the jet box) is installed with the isolation device and a circulating jet cooling device (RJC) at this position; in order to supplement the cooling capacity, two air cooling devices (AJC) are installed at this position.

[0044] Further, the rapid cooling section and the slow cooling section are each provided with a set of hydrogen and oxygen detection instruments to monitor the hydrogen content and oxygen content of the rapid cooling section and participate in the opening and closing interlocking of the hydrogen total valve.

[0045] Further, the slow cooling section and the rapid cooling section are each connected with an HN mixed gas main pipe and a nitrogen pipe, and each is provided with a set of hydrogen and oxygen detection instruments to monitor the hydrogen content and oxygen content of the rapid cooling section and participate in the opening and closing interlocking of the hydrogen total valve.

[0046] After the slow cooling section is supplied with hydrogen, it is necessary to accurately grasp the atmosphere in the rapid cooling section in real time to ensure safe production. In the original design, the pipe cooling section, the slow cooling section and the rapid cooling section of the annealing furnace share a set of furnace atmosphere detection instruments (oxygen content, hydrogen content, dew point) for circulating sampling. There is a certain time difference between the actual value and the displayed value, which cannot reflect the actual atmosphere of each furnace section in real time. In order to ensure the safe production of the rapid cooling section, a set of hydrogen and oxygen detection instruments are added to the rapid cooling section to monitor the hydrogen content and oxygen content of the rapid cooling section and participate in the opening and closing interlocking of the hydrogen total valve.

[0047] Taking the slow cooling section as an example, the HN mixed gas main pipe is connected to the slow cooling section on the drive side or the operation side in front of the furnace, that is, the commonly used N2 main pipe is changed into the HN mixed gas main pipe, and the HN mixed gas is sent into the furnace through the protection gas inlet hole; the other side of the slow cooling section is connected with the nitrogen pipe, and the nitrogen pipe is used to supply nitrogen; the HN and N2 are mixed in the furnace to reach the set H2 concentration.

[0048] Further, when the process requires H2 in the fast cooling section and no H2 in the slow cooling section, the HN mixed gas pipeline from the 1# nitrogen-hydrogen mixer to the slow cooling section is closed; at this time, the nitrogen in the slow cooling section can only be sent into the furnace through one side of the furnace body, which can meet the process requirements.

[0049] Considering the flow amount of the slow cooling section atmosphere to the pipe cooling section and the diffusion amount of the isolation section, it is calculated that N2 of 2500 m 3 / h and H2 of about 100 m 3 / h are needed. The flow and ratio of the NH mixed gas and nitrogen are used to complete the control of the atmosphere and furnace pressure of the slow cooling section. However, considering that the amount of N2 entering the fast cooling section and the slow cooling section will increase, respectively reaching 500 m 3 / h and 400-500 m 3 / h, and the existing pipeline can only provide 200 m 3 / h and 200 m 3 / h respectively, all of the 400 m 3 / h can be sent to the fast cooling section to participate in the control of the furnace pressure of the fast cooling section. The N2 of the slow cooling section comes from the commonly used low-pressure nitrogen, which participates in the control of the furnace pressure of the slow cooling section. The gas source can provide about 1000 m 3 / h, and at present, the gas source (commonly used low-pressure nitrogen) is only used for some small user points, such as the inlet and outlet sealing chambers and the coal gas blowing points. Therefore, it can be used to provide nitrogen for the slow cooling section without affecting the normal work of other equipment.

[0050] Further, a 10 mm gap is left between the sealing plate 5 and the side wall of the shell, facilitating the up and down movement of the sealing plate 5.

[0051] The labyrinth passage 9 is provided between the sealing plate 5 and the diffusion passage port, and the labyrinth passage 9 is filled with sealing fibers, which plays a role of isolation.

[0052] The upper end of the shell is provided with an isolator upper cover 1, and the pressure regulating valve penetrates through the isolator upper cover 1, and the bottom of the shell is provided with a frame base 6.

[0053] The length of the shell of the furnace area isolation device is the same as the length of the first section of the fast cooling section.

[0054] The above is only a preferred embodiment of the present application, and of course cannot limit the scope of the present application, so equivalent changes made in the scope of the patent application of the present application still fall within the protection scope of the present application.

Claims

1. A furnace zone isolation device control method characterized by, The method comprises the following steps: The atmosphere of the slow cooling section of the strip annealing furnace is isolated from the atmosphere of the fast cooling section by a furnace zone isolation device; the amount of nitrogen-hydrogen mixed gas HN and nitrogen N2 supplied to the slow cooling section is adjusted, and the amount of nitrogen N2 supplied to the fast cooling section is adjusted to achieve a set furnace pressure sequence and ensure that the furnace pressure P6 of the fast cooling section is greater than the furnace pressure P2 of the slow cooling section; The furnace zone isolation device control method further comprises that the furnace pressures of the slow cooling section and the fast cooling section are both connected with high-pressure nitrogen, and the specific process is as follows: when the furnace pressure P6 of the fast cooling section is lower than a safety set value or the hydrogen content in the fast cooling section is greater than 2%, the high-pressure nitrogen supply to the fast cooling section is started to make the furnace pressure P6 of the fast cooling section return to the safety set value and the hydrogen content in the fast cooling section be not greater than 2%, thereby maintaining safety production; When the furnace pressure P2 of the slow cooling section is lower than a safety set value, the high-pressure nitrogen supply to the slow cooling section is started to maintain safety production, and after the furnace pressure P2 of the slow cooling section returns to the set value, the high-pressure nitrogen supply is stopped while ensuring that P6>P2 to prevent the atmosphere of the slow cooling section from diffusing into the fast cooling section; The furnace zone isolation device comprises a shell, two sealing plates and a controller, the shell is arranged between the slow cooling section and the fast cooling section, the two sealing plates are arranged at the inlet end and the outlet end of the shell respectively, the two sealing plates are both connected with a lifting mechanism, and the controller is connected with the lifting mechanism through a frequency converter.

2. The furnace zone isolation device control method of claim 1, wherein, The lifting mechanism comprises a worm gear, a worm and a motor, the upper end of the sealing plate is connected with the worm, and the worm gear is engaged with the worm.

3. The furnace zone isolation device control method of claim 1, wherein, The shell is provided with a diffusion channel arranged between the two sealing plates, and the diffusion channel is provided with a pressure regulating valve.

4. The furnace zone isolation device control method of claim 1, wherein, The pressure P4 of the diffusion channel of the furnace zone isolation device is connected with an automatic regulating valve on the diffusion channel to control the furnace pressure at the P4 point to be at a set value. The pressure P5 at the inlet of the fast cooling section is greater than the pressure P3 at the outlet of the slow cooling section, and the pressure P3 at the outlet of the slow cooling section is greater than the pressure P4 of the diffusion channel of the furnace zone isolation device.

5. The furnace zone isolation device control method of claim 4, wherein, The pressure regulating valve comprises a manual butterfly valve and a ring slit adjusting device, the manual butterfly valve is arranged on the diffusion channel, the ring slit adjusting device comprises a telescopic cylinder, the two ends of the telescopic cylinder are hingedly connected with the manual butterfly valve and the upper end of the shell respectively, and a connecting rod is connected between the telescopic cylinder and the manual butterfly valve.

6. The furnace zone isolation device control method of claim 1, wherein The furnace zone isolation device further comprises a circulating spray cooling device connected with the inner cavity of the shell.

7. The furnace zone isolation device control method of claim 1, wherein HN mixed gas headers and nitrogen pipelines are connected to the slow cooling section and the fast cooling section, and a set of hydrogen and oxygen detection instruments are arranged in the slow cooling section and the fast cooling section.

8. The furnace zone isolation device control method of claim 1, wherein, When the process requires that the fast cooling section contains H2 and the slow cooling section does not contain H2, the HN mixed gas pipeline from the nitrogen-hydrogen mixer to the slow cooling section is closed; at this time, the nitrogen in the slow cooling section can only be supplied into the furnace through one side of the furnace body.

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