Regenerative reducing gas one-step heating furnace device

Abstract

This utility model belongs to the field of low-carbon metallurgical technology and provides a regenerative reducing gas one-step heating furnace device, including: two or more regenerative heating furnaces, each regenerative heating furnace including a burner and a regenerator chamber, the burner being connected to a gas pipeline for introducing coal gas and an air pipeline for introducing air, the regenerator chamber being connected to an exhaust pipe, and each regenerative heating furnace being connected to a cold reducing gas supply pipeline and a hot reducing gas output pipeline; the cold reducing gas supply pipeline is connected to the regenerative heating furnace for introducing cold reducing gas into the regenerative heating furnace, so as to achieve the effect of regeneration through storage. The hot chamber performs heat exchange; the hot reducing gas output pipeline is connected to the regenerative heating furnace to send out the hot reducing gas formed after heat exchange with the regenerative chamber; the mixing system is used to adjust the air intake to mix with the hot reducing gas output from the hot reducing gas output pipeline to form a reducing gas with a stable air temperature; the reducing gas main pipeline is connected downstream of the hot reducing gas output pipeline to transport the reducing gas with a stable air temperature to the vertical furnace; this utility model uses two or more regenerative heating furnaces to alternately supply air, forming a continuous and stable air temperature to be sent into the vertical furnace, which meets the inlet air temperature of the vertical furnace.

Description

Technical Field

[0001] This utility model relates to the field of low-carbon metallurgical technology, and in particular to a regenerative reducing gas one-step heating furnace device. Background Technology

[0002] With global warming, green and low-carbon metallurgy has become a new trend in the global steel industry. Gas-based shaft furnaces, as an important means of achieving low-carbon metallurgy, directly affect production through the reduction gas temperature and the operating rate of the heating furnace.

[0003] Currently, the most popular reducing gas heating methods both domestically and internationally are tubular furnaces. However, due to limitations in the material of the metal tubing, the maximum design temperature of tubular furnaces is 950℃, severely restricting the inlet temperature of the vertical shaft furnace. To achieve the required inlet temperature (950℃-1200℃), both the HYL and Midrex processes increase the inlet blast temperature by injecting oxygen. However, increasing the blast temperature has limitations and affects the composition of the reducing gas at the inlet.

[0004] Furthermore, both HYL's tubular heaters and Midrex's reformers experience carbon deposition issues between 400℃ and 700℃, affecting the lifespan of the furnace tubes. The main solution to this problem is periodic coking. However, in current processes, the coking process negatively impacts the metallization rate of the vertical shaft furnace during normal operation, reducing its operating rate.

[0005] Hot blast stoves, as a relatively mature technology in blast furnace systems, can continuously and stably increase the blast temperature of the blast furnace by burning inexpensive, low-calorific-value gas. Therefore, based on the hot blast stove, this utility model patent improves the supporting system of the hot blast stove, proposing a regenerative reducing gas one-step heating furnace device for use in vertical shaft furnace production. Utility Model Content

[0006] This utility model provides a regenerative reducing gas one-step heating furnace device, which directly heats the reducing gas to the required temperature at the inlet of the vertical furnace, thereby solving the technical problem that existing tubular heating furnaces cannot meet the inlet air temperature of the vertical furnace. By changing furnaces for purging and using non-forced air heating furnaces for periodic coking, the technical problem that carbon precipitation and coking in tubular heating furnaces affect the productivity of the vertical furnace is solved.

[0007] This utility model provides a regenerative reducing gas one-step heating furnace device, which includes:

[0008] Two or more regenerative heating furnaces, each of the regenerative heating furnaces including a burner and a regenerative chamber, the burner being connected to a gas pipeline for introducing coal gas and an air pipeline for introducing air, the regenerative chamber being connected to a flue gas pipeline, and each of the regenerative heating furnaces being connected to a cold reducing gas supply pipeline and a hot reducing gas output pipeline.

[0009] The cold reducing gas supply pipeline is connected to the regenerative heating furnace and is used to introduce cold reducing gas into the regenerative heating furnace for heat exchange through the heat storage chamber; the hot reducing gas output pipeline is connected to the regenerative heating furnace and is used to send out the hot reducing gas formed after heat exchange with the heat storage chamber.

[0010] The air mixing system is used to regulate the intake air volume to mix with the hot reducing gas output from the hot reducing gas output pipeline to form reducing gas with a stable air temperature.

[0011] The reducing gas main pipeline is connected downstream of the hot reducing gas output pipeline and is used to deliver reducing gas with a stable blast temperature to the vertical furnace.

[0012] In one embodiment of the present invention, at least two of the regenerative heating furnaces can alternately supply air, and each of the regenerative heating furnaces has a combustion working state and an air supply working state, wherein at least one of the regenerative heating furnaces is in the combustion working state while at least one of the regenerative heating furnaces is in the air supply working state.

[0013] In one embodiment of the present invention, the reducing gas is a reducing gas containing H2, a reducing gas containing CO, or a reducing gas containing both H2 and CO.

[0014] In one embodiment of the present invention, the regenerative reducing gas one-step heating furnace device further includes a purging device, which is used to purge the regenerative heating furnace before the regenerative heating furnace enters the air supply working state from the combustion working state.

[0015] In one embodiment of the present invention, a coking system is also included, and each of the regenerative heating furnaces is connected to the coking system.

[0016] When the coking cycle arrives, the coking system is activated by periodically coking through a non-blown heating furnace, and coking is carried out without affecting the production rate of the vertical furnace.

[0017] The beneficial effects of this utility model are as follows: The regenerative reducing gas one-step heating furnace device proposed in this utility model is configured with two or more regenerative heating furnaces. Coal gas and air are introduced and burned in the regenerative heating furnaces. Cold reducing gas is introduced into the regenerative heating furnaces through a cold reducing gas supply pipeline and enters the regenerative chamber for heat exchange to form hot reducing gas. The hot reducing gas enters the hot reducing gas output pipeline and mixes with the air intake of the mixing system to form reducing gas with a stable air temperature. Finally, the reducing gas enters the main reducing gas pipeline and is delivered to the vertical furnace with the reducing gas reaching the specified air temperature. The two or more regenerative heating furnaces can alternately supply air to form a continuous and stable air temperature supplied to the vertical furnace, which meets the inlet air temperature of the vertical furnace. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0019] In the attached diagram:

[0020] Figure 1 This is a schematic diagram of the structure of a single heating furnace in a regenerative reducing gas one-step heating furnace device provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a regenerative reducing gas one-step heating furnace device with two heating furnaces provided in an embodiment of this utility model;

[0022] Figure 3 A schematic diagram of a regenerative reducing gas one-step heating furnace device with three heating furnaces provided in an embodiment of this utility model;

[0023] Figure 4 This is a schematic diagram of a regenerative reducing gas one-step heating furnace device with four heating furnaces, provided in one embodiment of the present invention.

[0024] The attached figures are labeled as follows:

[0025] 1-Regenerative heating furnace; 2-Burner; 3-Regenerative chamber; 4-Gas pipeline; 5-Air pipeline; 6-Flue gas pipeline; 7-Cold reducing gas supply pipeline; 8-Hot reducing gas output pipeline; 9-Mixing system; 10-Main reducing gas pipeline; 11-Coking system. Detailed Implementation

[0026] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0027] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0029] Please see Figures 1 to 4 This utility model exemplarily proposes a regenerative reducing gas one-step heating furnace device, comprising:

[0030] Two or more regenerative heating furnaces 1, each regenerative heating furnace 1 includes a burner 2 and a regenerator 3, the burner 2 is connected to a gas pipeline 4 for introducing gas and an air pipeline 5 for introducing air, the regenerator 3 is connected to a flue gas pipeline 6, and each regenerative heating furnace 1 is connected to a cold reducing gas supply pipeline 7 and a hot reducing gas output pipeline 8.

[0031] The cold reducing gas supply pipeline 7 is connected to the regenerative heating furnace 1 and is used to introduce cold reducing gas into the regenerative heating furnace 1 for heat exchange through the heat storage chamber 3; the hot reducing gas output pipeline 8 is connected to the regenerative heating furnace 1 and is used to send out the hot reducing gas formed after heat exchange with the heat storage chamber 3.

[0032] The air mixing system 9 is used to adjust the air intake volume to mix with the hot reducing gas output from the hot reducing gas output pipeline 8 to form a reducing gas with a stable air temperature.

[0033] The reducing gas main pipeline 10 is connected downstream of the hot reducing gas output pipeline 8 and is used to deliver reducing gas with a stable blast temperature to the vertical furnace.

[0034] It should be noted that in the existing technology, both the tubular heater of the HYL process and the reformer of the MIDREX process have carbon precipitation problems between 400℃ and 700℃, which affects the life of the heater. Since the maximum design temperature of the tubular heater is 950℃, it severely limits the inlet temperature of the vertical furnace. In order to meet the inlet temperature requirements of the vertical furnace (950℃-1200℃), the existing processes all use oxygen injection to increase the inlet air temperature of the vertical furnace. However, oxygen injection will affect the composition of the reducing gas at the inlet of the vertical furnace, and the process requires two heating cycles. Therefore, this embodiment provides a regenerative reducing gas one-step heater device, which uses two or more regenerative heaters to alternate combustion and air supply. When one regenerative heater 1 supplies air, another regenerative heater 1 is burning. Through the adjustment of the air mixing system 9, the air supply temperature can always meet the inlet temperature requirements of the vertical furnace, and can provide a continuous and stable air temperature for the vertical furnace without stopping the furnace or affecting the production of the vertical furnace.

[0035] In the regenerative reducing gas one-step heating furnace device provided by this utility model, two or more regenerative heating furnaces 1 are set up, and coal gas and air are introduced into the regenerative heating furnace 1 for combustion. Cold reducing gas is introduced into the regenerative heating furnace 1 through the cold reducing gas supply pipeline 7 and enters the heat storage chamber 3 for heat exchange to form hot reducing gas. The hot reducing gas enters the hot reducing gas output pipeline 8 and mixes with the air intake of the mixing system 9 to form reducing gas with a stable air temperature. Finally, it enters the reducing gas main pipeline 10 to deliver the reducing gas with the specified air temperature to the vertical furnace. The two or more regenerative heating furnaces 1 can alternately supply air to form a continuous and stable air temperature to be supplied to the vertical furnace to meet the inlet air temperature of the vertical furnace.

[0036] Understandably, the gas pipeline 4 is used to connect the regenerative heater 1 to the gas system to supply gas to the regenerative heater 1, and the air pipeline 5 is used to connect the regenerative heater 1 to the air system to supply air to the regenerative heater 1.

[0037] In this embodiment, at least two regenerative heating furnaces 1 can alternately supply air. Each regenerative heating furnace 1 has a combustion working state and an air supply working state. Specifically, at least one regenerative heating furnace 1 is in the combustion working state while at least one regenerative heating furnace 1 is in the air supply working state. Each regenerative heating furnace 1 needs to perform a cycle of "combustion-furnace replacement-air supply-furnace replacement". When the regenerative heating furnace 1 is in the combustion working state, gas and air are introduced through the gas pipeline 4 and the air pipeline 5. The gas and air are burned in the burner 2 to produce high-temperature flue gas. The heat storage chamber 3 has a heat storage body built with checker bricks. The high-temperature flue gas will heat the heat storage body. Heating and cold reducing gas supply pipeline 7 introduces cold reducing gas into the furnace. At least part of the cold reducing gas enters the regenerator 3 for heat exchange to form hot reducing gas. The hot reducing gas can be mixed with another part of the cold reducing gas and then enters the hot reducing gas output pipeline 8. When the regenerable heating furnace 1 is in the air supply working state, the air intake is adjusted by the air mixing system 9. The air intake of the air mixing system 9 is mixed with the hot reducing gas output by the hot reducing gas output pipeline 8 to form reducing gas at a specified air temperature. The specified air temperature refers to the inlet air temperature required by the vertical furnace. By mixing the hot reducing gas and cold reducing gas and adjusting the air intake, the air temperature is regulated, so that the reducing gas main pipeline 10 can deliver a stable air temperature to the vertical furnace.

[0038] In some embodiments, the regenerative reducing gas one-step heater also includes a purging device. The purging device is used to purge the regenerative heater 1 during furnace changeover. Specifically, the purging device includes steam purging, nitrogen purging, and cold reducing medium purging. Steam purging is used before the regenerative heater 1 switches from air supply to combustion to remove some carbon deposits in the 400-700°C range during heat exchange between the cold reducing gas and the regenerator. Nitrogen purging is used during furnace changeover (including switching from combustion to air supply and vice versa) to drive away combustible components remaining inside the regenerative heater 1. Cold reducing medium purging generally follows nitrogen purging and is used when the regenerative heater 1 switches from combustion to air supply to purge nitrogen cleanly and prevent nitrogen from mixing into the reducing gas and affecting its composition.

[0039] In the above embodiments, the air mixing system 9 is installed on the main reducing gas pipeline 10, or on the hot reducing gas output pipeline 8 of each regenerative heating furnace 1.

[0040] In this embodiment, the regenerative reducing gas one-step heating furnace device also includes a coking system 11. Each regenerative heating furnace 1 is connected to the coking system 11. Specifically, when carbon-containing media precipitates carbon on the heat storage body built with checker bricks, the coking system 11 can periodically perform online coking on the regenerative heating furnace 1 without shutting down the furnace. By alternately introducing steam and air into the coking system 11, which is connected to each regenerative heating furnace 1, the steam and air entering the regenerative heating furnace 1 will burn off the coke on the heat storage body, solve the carbon precipitation problem, and extend the life of the heat storage body.

[0041] In some embodiments, the reducing gas is a reducing gas containing H2, a reducing gas containing CO, or a reducing gas containing both H2 and CO; this is not limited herein.

[0042] In the above embodiments, the number of regenerative heating furnaces 1 is set to two, three, four or more.

[0043] In one embodiment, when there are two regenerative heaters 1, in the initial state, one regenerative heater 1 enters the combustion working state, and the other regenerative heater 1 serves as a standby. When the regenerative heater 1 in the combustion working state enters the air supply working state, the other standby regenerative heater 1 enters the combustion working state. At this time, one regenerative heater 1 is in the combustion working state, and the other regenerative heater 1 is in the air supply working state. That is, the two regenerative heaters 1 are in a "one-burning-one-supplying" working state. Specifically, by having the two regenerative heaters 1 alternately enter the combustion working state and the air supply working state, it can be ensured that when the air temperature delivered to the vertical furnace by one regenerative heater 1 decreases, the other regenerative heater 1 will supply air, ensuring that the regenerative heater 1 delivers a continuous and stable air temperature to the vertical furnace, which can always meet the air temperature requirements at the entrance of the vertical furnace.

[0044] In one embodiment, when there are three regenerative heating furnaces 1, in the initial state, two regenerative heating furnaces 1 enter the combustion working state, and the other regenerative heating furnace 1 serves as a standby. When the two regenerative heating furnaces 1 in the combustion working state enter the air supply working state, the other standby regenerative heating furnace 1 enters the combustion working state. At this time, one regenerative heating furnace 1 is in the combustion working state, and two regenerative heating furnaces 1 are in the air supply working state, that is, the three regenerative heating furnaces 1 are in the "one combustion and two air supply" working state.

[0045] Alternatively, when there are three regenerative heaters 1, in the initial state, one regenerative heater 1 enters the combustion working state, and the other two regenerative heaters 1 serve as backups. When the regenerative heater 1 in the combustion working state transitions to the air supply working state, the other two backup regenerative heaters 1 enter the combustion working state. At this time, two regenerative heaters 1 are in the combustion working state, and one regenerative heater 1 is in the air supply working state, that is, the three regenerative heaters 1 operate in a "two-burn, one-supplier" working state. When maintenance is required, one regenerative heater 1 is in the maintenance shutdown state, while the other two regenerative heaters 1 operate normally. It is necessary to ensure that at least one regenerative heater 1 is in the air supply working state, and the other two regenerative heaters 1 operate in a "one-burn, one-supplier" working state. Maintenance does not require shutdown and will not affect production.

[0046] In one embodiment, when there are four regenerative heating furnaces 1, in the initial state, two regenerative heating furnaces 1 enter the combustion working state, and the other two regenerative heating furnaces 1 serve as backups. When the two regenerative heating furnaces 1 in the combustion working state enter the air supply working state, the other two backup regenerative heating furnaces 1 enter the combustion working state. At this time, two regenerative heating furnaces 1 are in the combustion working state, and two regenerative heating furnaces 1 are in the air supply working state. That is, the four regenerative heating furnaces 1 are in a "two-burning and two-supplying" working state. Specifically, when maintenance is required, one regenerative heating furnace 1 is in the maintenance shutdown state, while the other three regenerative heating furnaces 1 work normally, operating in a "one-burning and two-supplying" working state. Maintenance does not require shutdown and will not affect production.

[0047] Alternatively, when there are four regenerative heaters 1, in the initial state, one regenerative heater 1 enters the combustion working state, and the other three regenerative heaters 1 serve as backups. When the regenerative heater 1 in the combustion working state transitions to the air supply working state, the other three regenerative heaters 1 also enter the combustion working state. At this time, three regenerative heaters 1 are in the combustion working state, and one regenerative heater 1 is in the air supply working state, that is, the four regenerative heaters 1 operate in a "three-burn-one-supply" state. Specifically, when maintenance is required, one regenerative heater 1 is in the maintenance shutdown state, and the other three regenerative heaters 1 operate normally. It is necessary to ensure that at least one regenerative heater 1 is in the air supply working state, and the other three regenerative heaters 1 operate in a "two-burn-one-supply" working state. If two regenerative heaters 1 are in the maintenance shutdown state, the other two regenerative heaters 1 operate in a "one-burn-one-supply" working state. Maintenance does not require shutdown and will not affect production.

[0048] In summary, in the regenerative reducing gas one-step heating furnace device provided by this utility model, two or more regenerative heating furnaces 1 are set up, and coal gas and air are introduced into the regenerative heating furnace 1 for combustion. Cold reducing gas is introduced into the regenerative heating furnace 1 through the cold reducing gas supply pipeline 7 and enters the regenerative chamber 3 for heat exchange to form hot reducing gas. The hot reducing gas enters the hot reducing gas output pipeline 8 and mixes with the air intake of the mixing system 9 to form reducing gas with a stable air temperature. Finally, it enters the reducing gas main pipeline 10 to deliver the reducing gas with the specified air temperature to the vertical furnace. The two or more regenerative heating furnaces 1 can alternately supply air to form a continuous and stable air temperature to be supplied to the vertical furnace, which meets the inlet air temperature of the vertical furnace.

[0049] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A regenerative reducing gas one-step heating furnace device, characterized in that, include: Two or more regenerative heating furnaces, each of the regenerative heating furnaces including a burner and a regenerative chamber, the burner being connected to a gas pipeline for introducing coal gas and an air pipeline for introducing air, the regenerative chamber being connected to a flue gas pipeline, and each of the regenerative heating furnaces being connected to a cold reducing gas supply pipeline and a hot reducing gas output pipeline. The cold reducing gas supply pipeline is connected to the regenerative heating furnace and is used to introduce cold reducing gas into the regenerative heating furnace for heat exchange through the heat storage chamber; the hot reducing gas output pipeline is connected to the regenerative heating furnace and is used to send out the hot reducing gas formed after heat exchange with the heat storage chamber. The air mixing system is used to regulate the intake air volume to mix with the hot reducing gas output from the hot reducing gas output pipeline to form reducing gas with a stable air temperature. The reducing gas main pipeline is connected downstream of the hot reducing gas output pipeline and is used to deliver reducing gas with a stable blast temperature to the vertical furnace.

2. The regenerative reducing gas one-step heating furnace device according to claim 1, characterized in that, At least two of the regenerative heating furnaces are capable of alternating air supply, and each of the regenerative heating furnaces has a combustion working state and an air supply working state, wherein at least one of the regenerative heating furnaces is in the combustion working state while at least one of the regenerative heating furnaces is in the air supply working state.

3. The regenerative reducing gas one-step heating furnace device according to claim 1, characterized in that, The reducing gas is a reducing gas containing H2, a reducing gas containing CO, or a reducing gas containing both H2 and CO.

4. The regenerative reducing gas one-step heating furnace device according to claim 1, characterized in that, It also includes a purging device, which is used to purge the regenerative heater before it switches from combustion mode to air supply mode.

5. The regenerative reducing gas one-step heating furnace apparatus according to claim 1, characterized in that, It also includes a coking system, with each of the regenerative heating furnaces connected to the coking system.

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