阅读说明：本技术 一种高炉热风炉余热回收区域盲板拆除方法 (Method for removing blind plate in waste heat recovery area of blast furnace hot blast stove ) 是由 杨国新 柏徳春 李建东 艾中路 沈志宏 邹林 于 2019-03-15 设计创作，主要内容包括：本发明涉及一种高炉热风炉余热回收区域盲板拆除方法,其拆除步骤是：热风炉本体通过废气排压管与烟囱联通,形成对空通道,在烟囱抽力的作用下,烟气管道两端盲板两侧的压力、气体源即可消除；在烟气盲板靠预热器侧管道外部上方预设的“天窗”,烟气管道内部即与大气联通,形成对空状态；在助燃空气盲板靠预热器侧管道外部上方预设的“天窗”后,助燃空气管道内部即与大气联通,形成对空状态,在助燃空气管道内对盲板实施切割作业；盲板靠预热器侧管道外部上方预设的“天窗”,靠煤气预热器侧煤气管道内部即与大气联通,形成对空状态。能够消除原密闭空间作业的隐患,有效缩短高炉配合休风时间,降低生产成本。(The invention relates to a method for removing a blind plate in a waste heat recovery area of a blast furnace hot blast stove, which comprises the following steps: the hot blast stove body is communicated with a chimney through a waste gas exhaust pipe to form an empty passage, and under the action of chimney suction, the pressure and gas source on two sides of blind plates at two ends of a flue gas pipeline can be eliminated; a 'skylight' is preset above the outer part of the flue gas blind plate close to the side pipeline of the preheater, and the inner part of the flue gas pipeline is communicated with the atmosphere to form an opposite-empty state; after a skylight is preset above the outer part of the combustion air blind plate close to the side pipeline of the preheater, the inner part of the combustion air pipeline is communicated with the atmosphere to form an air-to-air state, and the blind plate is cut in the combustion air pipeline; the blind plate is close to a 'skylight' preset above the outer part of the side pipeline of the preheater, and the inner part of the side gas pipeline of the gas preheater is communicated with the atmosphere to form an opposite empty state. The hidden trouble of the original closed space operation can be eliminated, the blast furnace cooperation damping down time is effectively shortened, and the production cost is reduced.)

1. A method for dismantling a blind plate in a waste heat recovery area of a blast furnace hot blast stove is characterized by comprising the following dismantling steps:

firstly, stopping burning of the hot blast stove, after purging the hot blast stove body and the flue, opening a pressure exhaust valve of each hot blast stove, communicating the hot blast stove body with a chimney through a waste gas pressure exhaust pipe to form an air passage, namely eliminating the damage caused after abnormal gas enters the hot blast stove, closing the waste gas valve of the coal injection pulverizing station, and eliminating the pressure and gas source on two sides of blind plates at two ends of a flue gas pipeline under the action of chimney suction;

secondly, opening an inspection manhole at a flue reducer, communicating the inside of the flue gas pipeline with the atmosphere after a flue gas blind plate is close to a preset skylight arranged above the outer part of the pipeline at the side of the preheater to form a blank state, performing cutting operation on the blind plate in the flue gas pipeline by construction operators after the detection is qualified, sealing the skylight after the detection is finished, and putting the flue gas blind plate into operation after the leakage detection confirmation is performed;

thirdly, opening a fan bleeding valve after the combustion-supporting fan is stopped, and confirming; when a pressure discharge valve of the hot blast stove is opened and is communicated with a chimney, pressure and gas sources on two sides of a blind plate at the inlet and outlet ends of a combustion-supporting air pipeline can be eliminated, an overhaul manhole of the combustion-supporting air preheater is opened, after a skylight is preset above the outer portion of the combustion-supporting air blind plate close to the side of the preheater, the inner portion of the combustion-supporting air pipeline is communicated with the atmosphere, an air-to-air state is formed, after the detection is qualified, construction operators can perform cutting operation on the blind plate in the combustion-supporting air pipeline, the skylight is sealed after the detection is finished, and the operation can be carried out after the leakage detection is;

fourthly, the blind plate valve is closed or water is sealed to the blast furnace gas main pipe, nitrogen purging is carried out on the gas pipeline system through the blind plates under other gas pipelines, after the gas pipeline system is detected to be qualified, the gas blind plate removing operation can be carried out, the gas preheater maintenance manhole is opened, the bleeding valves on the two sides of the gas preheater blind plate are opened, and the gas pipeline blind plate side is enabled to be communicated with the atmosphere; after the blind plate is close to a 'skylight' preset above the outer part of the preheater side pipeline, the blind plate is close to the inner part of the gas pipeline on the side of the gas preheater and is communicated with the atmosphere, a blank state is formed, after the blind plate is detected to be qualified, construction operators can carry out cutting operation on the blind plate in the gas pipeline, the 'skylight' is sealed after the detection is finished, and the blind plate can be put into operation after the detection of the leak is confirmed.

2. The blast furnace hot blast stove waste heat recovery area blind plate demolition method according to claim 1, characterized in that: in order to strengthen the ventilation effect of flue gas, air and gas pipelines and newly opened 'skylights', a blower is arranged at a manhole of maintenance or equipment to perform forced ventilation on the interior of the pipeline.

3. The blast furnace hot blast stove waste heat recovery area blind plate demolition method according to claim 1, characterized in that: before entering the interior of the flue gas, air and gas pipelines, the gas pipelines are strictly detected and confirmed according to the operation requirement of a limited space; and the gas enters a gas pipeline close to the side of the preheater, and an operator is required to wear an aerobic gas detector and an air respirator and perform on-site monitoring.

4. The blast furnace hot blast stove waste heat recovery area blind plate demolition method according to claim 1, characterized in that: in order to prevent gas leakage accidents, a blind plate valve or a water seal field of a blast furnace gas main pipe is required to be monitored, and operators are informed to evacuate timely when abnormity is found.

Technical Field

The invention belongs to the technical field of blast furnace hot blast stove equipment, and relates to a method for removing a blind plate in a waste heat recovery area of a blast furnace hot blast stove.

Background

In the transformation process of the preheater in the waste heat recovery area of the blast furnace hot blast stove, if the outer sides of the electric butterfly valves of the air, coal gas and flue gas pipelines are separated by adopting a method of welding the blind plates, the original blind plates are detached and communicated with the original waste heat recovery system by utilizing the damping down opportunity of the blast furnace after the installation and the pressurization of the new preheater are finished, and the new preheater can be put into operation. The conventional method for removing the blind plate mainly comprises the steps of cutting pipelines on two sides of the blind plate from the outside of the pipeline and then performing blind plate extraction operation, wherein the cut pipelines have sedimentation with different degrees under the action of self weight, so that the pipelines on two sides of the original blind plate are seriously dislocated in the horizontal direction, and the pipeline butt joint difficulty is increased; or directly enters the interior of the pipeline from the manhole of the preheater equipment to carry out cutting operation, belongs to limited space operation, and has a plurality of uncontrollable influence factors because the inner space of the pipeline cannot be communicated with the external atmosphere; the existing methods cannot meet the field production requirements. Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a method for removing a blind plate in a waste heat recovery area of a blast furnace hot blast stove, which can eliminate the hidden trouble of the original closed space operation, after safety confirmation, operators can perform cutting operation on the blind plate in flue gas, air, coal gas and air pipelines, and can be put into operation after leakage detection confirmation, thereby effectively shortening the matched damping-down time of the blast furnace and reducing the production cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for removing a blind plate in a waste heat recovery area of a blast furnace hot blast stove comprises the following steps:

firstly, stopping burning of the hot blast stove, after purging the hot blast stove body and the flue, opening a pressure exhaust valve of each hot blast stove, communicating the hot blast stove body with a chimney through a waste gas pressure exhaust pipe to form an air passage, namely eliminating the damage caused after abnormal gas enters the hot blast stove, closing the waste gas valve of the coal injection pulverizing station, and eliminating the pressure and gas source on two sides of blind plates at two ends of a flue gas pipeline under the action of chimney suction;

secondly, opening an inspection manhole at a flue reducer, communicating the inside of the flue gas pipeline with the atmosphere after a flue gas blind plate is close to a preset skylight arranged above the outer part of the pipeline at the side of the preheater to form a blank state, performing cutting operation on the blind plate in the flue gas pipeline by construction operators after the detection is qualified, sealing the skylight after the detection is finished, and putting the flue gas blind plate into operation after the leakage detection confirmation is performed;

thirdly, opening a fan bleeding valve after the combustion-supporting fan is stopped, and confirming; when a pressure discharge valve of the hot blast stove is opened and is communicated with a chimney, pressure and gas sources on two sides of a blind plate at the inlet and outlet ends of a combustion-supporting air pipeline can be eliminated, an overhaul manhole of the combustion-supporting air preheater is opened, after a skylight is preset above the outer portion of the combustion-supporting air blind plate close to the side of the preheater, the inner portion of the combustion-supporting air pipeline is communicated with the atmosphere, an air-to-air state is formed, after the detection is qualified, construction operators can perform cutting operation on the blind plate in the combustion-supporting air pipeline, the skylight is sealed after the detection is finished, and the operation can be carried out after the leakage detection is;

and fourthly, closing a blind plate valve or water sealing operation on a blast furnace gas main pipe, purging nitrogen on a gas pipeline system by using a blind plate under other gas pipelines, removing the gas blind plate after the gas blind plate is detected to be qualified, opening a gas preheater maintenance manhole, and opening bleeding valves on two sides of the gas preheater blind plate to enable the gas pipeline blind plate to be communicated with the atmosphere. After the blind plate is close to a 'skylight' preset above the outer part of the preheater side pipeline, the blind plate is close to the inner part of the gas pipeline on the side of the gas preheater and is communicated with the atmosphere, a blank state is formed, after the blind plate is detected to be qualified, construction operators can carry out cutting operation on the blind plate in the gas pipeline, the 'skylight' is sealed after the detection is finished, and the blind plate can be put into operation after the detection of the leak is confirmed.

Furthermore, in order to strengthen the ventilation effect of the flue gas, air and gas pipelines and newly opened 'skylights', a blower is arranged at a manhole of the overhaul or equipment to perform forced ventilation on the interior of the pipelines.

Furthermore, before entering the interior of the flue gas, air and gas pipelines, detection and confirmation are carried out according to the operation requirement of a limited space; and the gas enters a gas pipeline close to the side of the preheater, and an operator is required to wear an aerobic gas detector and an air respirator and perform on-site monitoring.

Furthermore, in order to prevent gas leakage accidents, the blind plate valve or the water seal site of the blast furnace gas main pipe is required to be monitored, and operators are informed to evacuate timely when abnormity is found.

The invention has the positive effects that:

after the blind plate is removed, serious horizontal dislocation of new and old pipelines of flue gas, air and coal gas can be caused, the blind plate is removed smoothly under the condition of very high pipeline butt joint difficulty, meanwhile, the hidden danger of cutting operation in the original limited space can be eliminated, the removal of the blind plate in the coal gas, air and flue pipeline is rapidly completed, and the blast furnace matched damping down time is shortened. 3200m which is currently available in a certain company³The method is applied to the process of removing the blind plate of the preheater of the blast furnace hot blast stove, the matching time of blast furnace damping down is shortened by 20 hours from the original 26 hours, the method is safe and controllable, the method can be popularized to the process of modifying the preheater of the hot blast stove of large, medium and small blast furnaces of the same industry, serious horizontal dislocation occurs to new and old pipelines of flue gas, air and coal gas after the blind plate is removed, and the blind plate is removed and applied under the condition that the pipeline butt joint difficulty is very large.

Drawings

Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention.

In the figure: 1-a flue gas inlet valve, 2-a blind plate, 3-a skylight, 4-a bleeding valve, 5-a gas outlet valve, 6-a gas preheater inspection manhole, 7-a gas inlet valve, 8-a flue gas outlet valve, 9-a coal injection pulverizing station waste gas valve, 10-a combustion air inlet valve, 11-an air preheater inspection manhole, 12-a combustion air outlet valve, 13-a waste gas exhaust pipe, 14-a pressure exhaust valve, 15-a hot blast stove and 16-a chimney.

Detailed Description

The present invention will be further described with reference to the following examples.

Referring to fig. 1, a method for removing a blind plate in a waste heat recovery area of a blast furnace hot blast stove comprises the following process steps:

firstly, the hot blast stove 15 stops burning, after sweeping the hot blast stove 15 body and the flue, the exhaust valve 14 of each hot blast stove 15 is opened, the hot blast stove 15 body is communicated with the chimney 16 through the waste gas exhaust pipe 13, an air passage is formed, and the harm in the hot blast stove 15 flue can be eliminated after abnormal gas enters the hot blast stove 15. Closing the waste gas valve 9 of the coal powder injection station, and eliminating the pressure and gas source at two sides of the four blind plates 2 behind the flue gas inlet valve 1 and in front of the flue gas outlet valve 8 under the action of the suction force of the chimney 16;

secondly, opening a flue maintenance manhole 3, cutting a 400 x 1000mm skylight 3 above the outer part of the flue gas blind plate 2 close to the preheater side pipeline, communicating the inner part of the flue gas pipeline with the atmosphere to form an empty state, after the detection is qualified, performing cutting operation on the blind plate 2 in the flue gas pipeline by construction operators, sealing the skylight 3 after the detection is finished, and putting the flue gas blind plate into operation after the leakage detection is confirmed;

thirdly, opening a fan bleeding valve after the combustion-supporting fan is stopped, and confirming; under the condition that a pressure discharge valve 14 of a hot blast stove 15 is opened and communicated with a chimney 16, the pressure and gas source on two sides of 2 blind plates 2 in front of a combustion air outlet valve 12 can be eliminated after a combustion air inlet valve 10. Opening a combustion air preheater maintenance manhole 11, cutting a 400 x 1000mm skylight 3 above the outer part of a combustion air blind plate close to a preheater side pipeline, communicating the inside of the combustion air pipeline with the atmosphere to form an empty state, after the detection is qualified, cutting the blind plate 2 in the combustion air pipeline by construction operators, sealing the skylight 3 after the detection is finished, and putting the blind plate into operation after the leakage detection is confirmed;

and fourthly, closing a blind plate valve or water sealing operation on the blast furnace gas main pipe, purging the gas pipeline system by nitrogen through the blind plates under other gas pipelines, and removing the gas blind plates after the gas pipeline system is detected to be qualified. And opening a gas preheater inspection manhole 6, opening a gas inlet valve 7 of the gas preheater, and then opening bleed valves 4 on two sides of 2 blind plates 2 in front of a gas outlet valve 5 to enable the sides of the blind plates of the gas pipeline to be communicated with the atmosphere. After 600 x 1000mm 'skylight' 3 is cut out to the outside top of the side pipeline of the preheater by the blind plate, the side gas pipeline of the gas preheater is connected with the atmosphere, a blank state is formed, after the detection is qualified, construction operators can implement cutting operation on the blind plate 2 in the gas pipeline, the 'skylight' 3 is sealed after the detection is finished, and the operation can be put into operation after the detection is confirmed.

In order to strengthen the ventilation effect of the flue gas, air and gas pipelines and newly opened 'skylights', an air blower is required to be arranged at the original manhole to perform forced ventilation on the interior of the pipeline.

Before entering the interior of the flue gas, air and gas pipelines, the gas pipelines are strictly detected and confirmed according to the operation requirement of a limited space; and the gas enters a gas pipeline close to the side of the preheater, and an operator is required to wear an aerobic gas detector and an air respirator and perform on-site monitoring.

In order to prevent gas leakage accidents, a blind plate valve or a water seal field of a blast furnace gas main pipe is required to be monitored, and operators are informed to evacuate timely when abnormity is found.

3200m, which is already available in a certain company³The method is applied to the process of dismantling the modified blind plate of the 15 preheater of the blast furnace hot blast stove, the matching time of blast furnace blowing down is shortened by 20 hours from the original 26 hours, the method is safe and controllable, the method can be popularized to the process of transforming the 15 preheater of the hot blast stove of large, medium and small blast furnaces of the same industry, serious horizontal dislocation occurs to new and old pipelines of flue gas, air and coal gas after the blind plate is dismantled, and the blind plate is dismantled and applied under the condition of very large pipeline butt joint difficulty.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent replacements, improvements, etc. within the principle of the present invention should be included in the protection scope of the present invention.