Device and process for fully recovering furnace top pressure-equalizing diffused coal gas

Abstract

The invention relates to a device for fully recovering furnace top pressure-equalizing diffused coal gas, which comprises a furnace top charging bucket, the furnace top charging bucket is respectively connected with a high-temperature high-pressure coal gas main pipe, a main diffusing pipe and a diffused coal gas pressure-equalizing pipe, the diffused coal gas pressure-equalizing pipe is connected with a dust remover, and the rear end of the dust remover is connected into a coal gas pipe network through a clean coal gas pipe; a first ejector is arranged on a diffused coal gas pressure equalizing pipe at the front end of the dust remover, an ejection port of the first ejector is connected with a high-temperature and high-pressure coal gas main pipe through an ejection pipeline I, a second ejector is arranged on a clean coal gas pipe at the rear end of the dust remover, and an ejection port of the second ejector is connected with the high-pressure coal gas main pipe through an ejection pipeline II. According to the device and the method, furnace top pressure-equalizing gas and damping-down gas can be completely recycled, the problem of gas diffusion to air is solved, and environmental pollution caused by pressure-equalizing diffusion and damping-down is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of steel industry, and in particular to a device for fully recovering furnace top pressure-equalizing and dispersing coal gas. Background Art

[0002] The gas released from the blast furnace top tank under pressure needs to be recovered urgently. At the same time, because blast furnaces are generally operated under high pressure and water cooling is often taken to protect the top equipment during the blast furnace shutdown process, these have led to high pressure and low temperature of the gas released from the top. It is in this context that many recovery technologies have been developed, but some of these technologies are difficult to promote on a large scale due to price issues, factors such as complicated operation and maintenance, or concerns about the impact on production.

[0003] The main working mode of the current blast furnace pressure equalization system is: when preparing to add materials to the furnace top tank, release the gas in the furnace top tank to the air until the pressure in the tank is the same as the atmospheric pressure, and start adding materials to the tank; when the charge in the tank is about to enter the furnace, the pressure equalization system uses pressure equalization gas to pressurize the tank until the pressure in the tank is equal to the pressure in the furnace, and start adding materials to the furnace. Usually this process requires two pressure equalizations, one of which uses clean gas or semi-clean gas, and the second uses nitrogen. Patent CN201410274381.2 is a process method and device for forced recovery of blast furnace vented gas, and proposes a method for gas recovery. This method achieves the goal of recovering 90% of the vented gas by adding an ejector and a fan, while protecting the environment while achieving economic benefits. In order to promote the development of technology, especially to ensure the full recovery of the gas at the furnace top and the gas during the wind-down process, and to solve a series of technical problems such as low gas temperature, pressure shock of the recovered gas to the clean gas pipeline network, low dust removal efficiency, and low recovery rate, it is particularly necessary to develop a new gas recovery process. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a device for fully recovering furnace top pressure-equalizing and venting coal gas, which can not only improve the gas recovery efficiency of blast furnace material tank, but also solve the problem of forced venting of blast furnace gas due to low temperature in accident state, thereby realizing full recovery of vented coal gas.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A device for fully recovering furnace top pressure-equalizing and releasing coal gas comprises a furnace top material tank, which is respectively connected to a high-temperature and high-pressure gas main, a main release pipe and a release gas pressure-equalizing pipe, the release gas pressure-equalizing pipe is connected to a dust collector, and the rear end of the dust collector is connected to a gas network through a clean gas pipe; a first ejector is provided on the release gas pressure-equalizing pipe at the front end of the dust collector, and an ejection port of the first ejector is connected to the high-temperature and high-pressure gas main through an ejection pipe one, and a second ejector is provided on the clean gas pipe at the rear end of the dust collector, and an ejection port of the second ejector is connected to the high-pressure gas main through an ejection pipe two.

[0007] The high-temperature and high-pressure gas main pipe, the main discharge pipe and the discharge gas equalizing pipe are all provided with a pressure relief valve group.

[0008] The first ejection pipe, the gas discharging equalizing pipe, the second ejection pipe and the clean gas pipe are all provided with a nitrogen purge valve group.

[0009] The first and second injection pipelines are both provided with gas injection valves.

[0010] A production process for a device for fully recovering furnace top pressure-equalizing and releasing coal gas. The raw coal gas discharged during the blast furnace shutdown and furnace top material tank pressure-equalizing and releasing process enters the releasing coal gas pressure-equalizing pipe through the pressure relief valve group, and then enters the first ejector. The first ejector introduces high-temperature and high-pressure coal gas from the ejection port to eject the raw coal gas in the furnace top material tank. In the first ejector, the high-temperature and high-pressure clean coal gas is mixed with the raw coal gas to form a mixed coal gas that meets the temperature requirement of the dust collector. After being purified by the dust collector, the mixed coal gas enters the second ejector. The second ejector introduces high-pressure coal gas from the ejection port, and uses the slight negative pressure generated by the high-pressure coal gas to attract the clean coal gas after dust removal. The high-pressure coal gas is mixed with the clean coal gas in the second ejector, and finally enters the gas network through the clean coal gas pipe.

[0011] The temperature of the high-temperature and high-pressure coal gas introduced by the first ejector is 135-150°C and the pressure is 0.2-0.3MPa.

[0012] The pressure of the high-temperature and high-pressure coal gas introduced by the second ejector is 0.2-0.3MPa.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. Install ejectors on the blast furnace vent gas equalizing pipeline and the clean gas pipeline at the rear end of the dust collector to ensure full recovery of the vent gas.

[0015] 2. The first ejector uses high-temperature and high-pressure clean coal gas as the ejection fluid, which increases the temperature and pressure of the suspended coal gas during the ejection and release process, ensuring that the low-temperature coal gas can be fully recovered during the suspended process and finally enter the dust collector.

[0016] 3. All the pressure-equalizing gas and wind-off gas on the furnace top can be recovered, which not only solves the problem of gas release to the air, but also prevents environmental pollution caused by pressure-equalizing release and wind-off. The control is simple and convenient, especially it can increase the temperature of low-temperature released gas. The promotion of gas release and recovery technology is of special significance for extending the life of gas pressure-equalizing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] In the figure: furnace top material tank 1, high-temperature and high-pressure gas main pipe 2, main vent pipe 3, vent gas equalizing pipe 4, dust collector 5, clean gas pipe 6, gas pipe network 7, first ejector 8, ejector pipeline one 9, second ejector 10, ejector pipeline two 11, high-pressure gas main pipe 12, pressure relief valve group 13, nitrogen purge valve group 14, gas ejector valve 15. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means more than two.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0022] like Figure 1A device for fully recovering furnace top pressure-equalizing and dispersing coal gas, comprising a furnace top material tank 1, which is respectively connected to a high-temperature and high-pressure gas main pipe 2, a main dispersing pipe 3 and a dispersing coal gas pressure-equalizing pipe 4, the dispersing coal gas pressure-equalizing pipe 4 is connected to a dust collector 5, and the rear end of the dust collector 5 is connected to a gas pipe network 7 through a clean coal gas pipe 6; a first ejector 8 is provided on the dispersing coal gas pressure-equalizing pipe 4 at the front end of the dust collector 5, and an ejection port of the first ejector 8 is connected to the high-temperature and high-pressure gas main pipe 2 through an ejection pipe 1 9, and a second ejector 10 is provided on the clean coal gas pipe 6 at the rear end of the dust collector 5, and an ejection port of the second ejector 10 is connected to a high-pressure gas main pipe 12 through an ejection pipe 2 11.

[0023] The high-temperature and high-pressure gas main pipe 2, the main discharge pipe 3 and the discharge gas equalizing pipe 4 are all provided with a pressure relief valve group 13.

[0024] The ejection pipe 1 9, the gas pressure equalizing pipe 4, the ejection pipe 2 11 and the clean gas pipe 6 are all provided with a nitrogen purge valve group 14 to ensure safety.

[0025] The gas injection valve 15 is provided on the injection pipe 1 9 and the injection pipe 2 11 .

[0026] A production process for a device for fully recovering furnace top pressure-equalizing and releasing coal gas. The raw coal gas discharged during the blast furnace shutdown and furnace top material tank pressure-equalizing and releasing process enters the releasing coal gas pressure-equalizing pipe 4 through the pressure relief valve group 12, and then enters the first ejector 8. The first ejector 8 introduces high-temperature and high-pressure coal gas from the ejection port to eject the raw coal gas in the furnace top material tank 1. In the first ejector 8, the high-temperature and high-pressure clean coal gas is mixed with the raw coal gas to form a mixed coal gas that meets the temperature requirement of the dust collector 5. After being purified by the dust collector 5, the mixed coal gas enters the second ejector 10. The second ejector 10 introduces high-pressure coal gas from the ejection port, and uses the slight negative pressure generated by the high-pressure coal gas to attract the clean coal gas after dust removal. The high-pressure coal gas is mixed with the clean coal gas in the second ejector 10, and finally enters the gas network 7 through the clean coal gas pipe 6.

[0027] The temperature of the high-temperature and high-pressure coal gas introduced by the first ejector 8 is 135-150°C, and the pressure is 0.2-0.3MPa.

[0028] The pressure of the high-temperature and high-pressure coal gas introduced by the second ejector 10 is 0.2-0.3 MPa.

[0029] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

[0030] In order to make the purpose, technical scheme and technical effect of the present invention clearer, the technical scheme in the embodiment of the present invention is now clearly and completely described. However, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. In combination with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1: In order to ensure that the furnace top material tank 1 can receive materials stably, the gas in the material tank must be released before receiving materials. The specific operation of the pressure equalization release of the furnace top material tank is: when releasing, first open the pressure relief valve group 13 on the release gas equalizing pipe 4, and at the same time cut off the high-temperature and high-pressure gas main pipe 2 and the main release pipe 3 to ensure that the released gas only passes through the furnace top release gas pipeline 4. At this time, the injection pipe 1 9 and the injection pipe 2 11 are in a closed state. The released gas enters the dust collector 5 after passing through multiple control valves. After dust removal is completed in the dust collector 5, the released gas becomes clean gas and is connected to the gas network 7 through the clean gas pipe 6. When the gas pressure in the later stage of release is reduced to a level close to the gas pressure in the clean gas network of the whole plant, the released gas can no longer be recovered naturally. At this time, it is necessary to use high-temperature and high-pressure gas to inject the blast furnace released gas.

[0032] The first ejector 8 on the ejection pipe 1 9 at the front end of the dust collector 5 allows the high-temperature and high-pressure coal gas of 140°C and 0.206MPa in the high-temperature and high-pressure coal main pipe 2 to enter the ejection port through the coal gas ejection valve 15, and the second ejector 10 on the ejection pipe 2 11 at the rear end of the dust collector 5 allows the high-pressure coal gas of 0.206MPa in the high-pressure coal main pipe 12 to enter the ejection port through the coal gas ejection valve 15, thereby forming a negative pressure in the cavity through the high-speed inflow of coal gas, ejecting the remaining vented coal gas in the furnace top material tank 1. Finally, this part of the coal gas enters the dust collector 5 for dust removal, and then enters the coal gas network 7, thereby realizing the full recovery of the vented coal gas.

[0033] Embodiment 2: Specific operation flow of blast furnace wind-off link: open the pressure relief valve group 13 on the venting gas pipeline, and cut off the high-temperature and high-pressure gas main pipe 2 and the main vent pipe 3 at the same time, so that all the furnace top gas only passes through the venting gas pipeline 4, and the ejector pipe 1 9 and the ejector pipe 2 11 are in a closed state. At the end of the wind-off period, when the furnace top gas pressure is as low as the gas pressure in the net gas network of the whole plant, the blast furnace wind-off gas can no longer be naturally recovered. At this time, the ejector pipe 1 9 and the ejector pipe 2 11 are fully opened, and the first ejector 8 allows the high-temperature and high-pressure gas of 145°C and 0.26MPa in the high-temperature and high-pressure gas main pipe 2 to enter the ejection port through the gas ejector valve 15, and the second ejector 10 allows the high-pressure gas of 0.26MPa in the high-pressure gas main pipe 12 to enter the ejection port through the gas ejector valve 15, ejecting the low-pressure coal gas on the furnace top during the wind-off process, thereby realizing the full recovery of the vented coal gas.

[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and basic spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for fully recovering furnace top pressure-equalizing and dispersing coal gas, characterized in that: It includes a furnace top material tank, which is respectively connected to the high-temperature and high-pressure gas main, the main vent pipe and the vent gas equalizing pipe; the vent gas equalizing pipe is connected to the dust collector, and the rear end of the dust collector is connected to the gas network through a clean gas pipe; a first ejector is provided on the vent gas equalizing pipe at the front end of the dust collector, and the ejection port of the first ejector is connected to the high-temperature and high-pressure gas main through an ejection pipe one; a second ejector is provided on the clean gas pipe at the rear end of the dust collector, and the ejection port of the second ejector is connected to the high-pressure gas main through an ejection pipe two.

2. The device for fully recovering furnace top pressure-equalizing and releasing coal gas according to claim 1 is characterized in that: The high-temperature and high-pressure gas main pipe, the main discharge pipe and the discharge gas equalizing pipe are all provided with a pressure relief valve group.

3. The device for fully recovering furnace top pressure-equalizing and releasing coal gas according to claim 1 is characterized in that: The first ejection pipe, the gas venting equalizing pipe, the second ejection pipe and the clean gas pipe are all provided with a nitrogen purge valve group.

4. The device for fully recovering furnace top pressure-equalizing and releasing coal gas according to claim 1 is characterized in that: The first and second injection pipelines are both provided with gas injection valves.

5. The production process of a device for fully recovering furnace top pressure-equalizing and dispersing coal gas according to claim 1, characterized in that: The raw gas discharged during the blast furnace shutdown and furnace top tank pressure equalization and release process enters the release gas equalization pipe through the pressure relief valve group, and then enters the first ejector. The first ejector introduces high-temperature and high-pressure gas from the ejection port to eject the raw gas in the furnace top tank. In the first ejector, the high-temperature and high-pressure clean gas is mixed with the raw gas to form a mixed gas that meets the temperature requirement of the dust collector. After being purified by the dust collector, the mixed gas enters the second ejector. The second ejector introduces high-pressure gas from the ejection port, and uses the slight negative pressure generated by the high-pressure gas to attract the clean gas after dust removal. The high-pressure gas is mixed with the clean gas in the second ejector, and finally enters the gas network through the clean gas pipe.

6. The production process of a device for fully recovering furnace top pressure-equalizing and dispersing coal gas according to claim 5, characterized in that: The temperature of the high-temperature and high-pressure coal gas introduced by the first ejector is 135-150°C and the pressure is 0.2-0.3MPa.

7. The production process of a device for fully recovering furnace top pressure-equalizing and dispersing coal gas according to claim 5, characterized in that: The pressure of the high-temperature and high-pressure coal gas introduced by the second ejector is 0.2-0.3MPa.

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