Blast furnace damping-down gas recovery system

Abstract

The utility model discloses a blast furnace damping-down gas recovery system which comprises an ejection medium source and an ejector, the ejector is connected with a blast furnace and the ejection medium source, a gas outlet of the ejector is connected with a low-pressure gas conveying header pipe through a gas recovery pipe, and the blast furnace damping-down gas recovery system further comprises a high-calorific-value gas source; the high-calorific-value fuel gas source is connected with the coal gas recovery pipe through a fuel gas supply header pipe, the high-calorific-value fuel gas source is used for supplying high-calorific-value fuel gas to the coal gas recovery pipe, and the calorific value of the high-calorific-value fuel gas is higher than that of the blast furnace damping-down coal gas recovered by the coal gas recovery pipe. When the blast furnace damping-down gas recycling system is applied, the heat value of the recycled blast furnace damping-down gas can be increased, burners of downstream users are not prone to flameout, and the safety of recycling of the blast furnace damping-down gas is improved.

Description

Technical Field

[0001] The present application relates to the technical field of blast furnace gas recovery, and in particular to a blast furnace off-gas recovery system. Background Art

[0002] Blast furnace gas is a by-product gas produced during blast furnace smelting, with a calorific value of about 3350KJ / Nm 3 After pressure reduction via a pressure-regulating valve group or a TRT device (blast furnace gas residual pressure turbine generator), the blast furnace top pressure can be reduced from 0.26MPa to 12KPa. Blast furnaces stop smelting operations for a certain period of time to undergo equipment inspection and maintenance. This period is known as the blast furnace shutdown period. During a blast furnace shutdown, the shutdown gas is often ejected and recovered using a shutdown ejector. Specifically, high-pressure gas is used as the ejection medium, and the ejector is used to draw the blast furnace shutdown gas into the low-pressure gas network behind the pressure reducing valve group until the blast furnace reaches a pressure-free state.

[0003] During blast furnace shutdown, the temperature and pressure of coal gas decrease, leading to a decrease in calorific value. In related technologies, the ejectors in blast furnace shutdown gas recovery systems often use nitrogen or other ejection media as their power source. Large amounts of nitrogen entering the gas recovery system further reduce the calorific value of the gas, making it more likely that the burners of downstream heating furnace users will flame out, leading to gas overflow from the burners and posing a significant safety hazard.

[0004] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects is still a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] The purpose of this application is to provide a blast furnace off-gas recovery system to increase the calorific value of the recovered blast furnace off-gas, making it difficult for the burners of downstream users to go out, and improving the safety of blast furnace off-gas recovery and use.

[0006] To solve the above technical problems, the present application provides a blast furnace off-air gas recovery system, comprising an ejector medium source and an ejector, wherein the ejector is connected to the blast furnace and the ejector medium source respectively, and the gas outlet of the ejector is connected to the low-pressure gas transmission main through a gas recovery pipe. The blast furnace off-air gas recovery system also includes a high calorific value fuel gas source;

[0007] The high calorific value gas source is connected to the gas recovery pipe through a gas supply main pipe. The high calorific value gas source is used to supply high calorific value gas to the gas recovery pipe. The calorific value of the high calorific value gas is higher than the calorific value of the blast furnace off-gas gas recovered by the gas recovery pipe.

[0008] Optionally, the blast furnace off-gas gas recovery system further includes a first regulating valve;

[0009] The first regulating valve is provided on the gas supply main pipe, and the first regulating valve is used to regulate the flow rate of the high calorific value gas supplied by the gas supply main pipe.

[0010] Optionally, the blast furnace off-air gas recovery system further includes a gas calorific value analyzer;

[0011] The gas calorific value analyzer is arranged in the gas recovery pipe and is located downstream of the connection between the gas supply main pipe and the gas recovery pipe. The gas calorific value analyzer is used to measure the calorific value of the gas in the gas recovery pipe.

[0012] Optionally, the gas supply main is provided with a shut-off valve, which is used to connect or shut off the gas supply main.

[0013] Optionally, the ejection medium source and the ejector are connected via an ejection medium supply pipe, and the ejection medium supply pipe is provided with a second regulating valve, and the second regulating valve is used to regulate the flow rate of the ejection medium supplied by the ejection medium supply pipe.

[0014] Optionally, the blast furnace off-gas gas recovery system further includes a controller;

[0015] The controller is connected to the first regulating valve, the coal gas calorific value analyzer, the shut-off valve and the second regulating valve respectively. The controller is used to control the opening of the shut-off valve and the first regulating valve according to the opening signal of the second regulating valve, and to control the closing of the shut-off valve and the first regulating valve according to the closing signal of the second regulating valve. The controller is used to control the opening of the first regulating valve according to the calorific value data measured by the coal gas calorific value analyzer.

[0016] Optionally, the gas supply main pipe and the gas recovery pipe are connected via a gas mixing device.

[0017] Optionally, the gas mixing device is an annular tube, which is sleeved on the circumferential outer side of the gas recovery pipe. The annular tube is provided with a first gas inlet and several gas outlets. The gas recovery pipe is provided with several second gas inlets. The number of the several second gas inlets and the several gas outlets are the same and correspond one to one. The gas outlet and the second gas inlet are connected through a gas supply branch pipe.

[0018] Optionally, a plurality of the gas outlets are evenly spaced along the circumference of the inner ring wall of the annular tube, and a plurality of the second gas inlets are evenly spaced along the circumference of the gas recovery pipe.

[0019] Optionally, the high calorific value fuel gas is any one of coke oven gas, natural gas, liquefied petroleum gas, or a mixture of any two or more thereof.

[0020] The blast furnace off-air gas recovery system provided in the present application is provided with an ejector which is respectively connected to the blast furnace and the ejection medium source, and the gas outlet of the ejector is connected to the low-pressure gas transmission main through the gas recovery pipe. At the same time, a high calorific value fuel gas source is provided which is connected to the gas recovery pipe through the gas supply main. When in use, the high calorific value fuel gas source can supply high calorific value fuel gas to the gas recovery pipe to increase the calorific value of the blast furnace off-air gas recovered by the gas recovery pipe, so that the calorific value of the gas entering the low-pressure gas transmission main is higher, so that the burner of the downstream user is not easy to extinguish, and the gas is not easy to overflow from the burner, thereby improving the safety of the recovery and use of the blast furnace off-air gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a blast furnace off-gas gas recovery system according to an embodiment of the present application;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of the connection between the ring pipe and the gas recovery pipe.

[0023] The reference numerals in the above drawings are described as follows:

[0024] 1- ejection medium source;

[0025] 2- ejector;

[0026] 3- High calorific value gas source;

[0027] 4-first regulating valve;

[0028] 5-Gas calorific value analyzer;

[0029] 6- Second regulating valve;

[0030] 7-Shut-off valve;

[0031] 8-gas mixing device, 8a-first gas inlet, 8b-gas outlet;

[0032] 91-Gas recovery pipe, 91a-Second gas inlet, 92-Low-pressure gas transmission main pipe, 93-Gas supply main pipe, 94-Ejector medium supply pipe, 95-Gas supply branch pipe, 96-Gas ejector pipe. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] It should be noted that the "downstream" mentioned in this application refers to the front of the gas flow direction in the corresponding pipeline. For example, the downstream of the gas recovery pipe 91 is the front of the blast furnace shut-off gas flow direction in the gas recovery pipe 91.

[0035] The terms "first", "second", etc. mentioned in this application are only used to facilitate the description of two or more structures or components with the same or similar structures and / or functions, and do not mean any special limitation on the order and / or importance.

[0036] The term “several” as used in this application refers to an indefinite number of multiple components, usually more than two; and when “several” is used to indicate the number of certain components, it does not indicate the quantitative relationship between these components.

[0037] In this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or a communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0038] Please refer to Figure 1 , Figure 1 This is a structural schematic diagram of the blast furnace off-gas gas recovery system of the embodiment provided in this application.

[0039] In the embodiment provided in the present application, the blast furnace shut-off gas recovery system includes an ejector medium source 1, an ejector 2 and a high calorific value fuel gas source 3. The ejector 2 is connected to the blast furnace (not shown in the figure) and the ejector medium source 1, respectively. The gas outlet of the ejector 2 is connected to the low-pressure gas delivery main 92 through the gas recovery pipe 91. The high calorific value fuel gas source 3 is connected to the gas recovery pipe 91 through the gas supply main 93. The high calorific value fuel gas source 3 is used to supply high calorific value fuel gas to the gas recovery pipe 91. The calorific value of the high calorific value fuel gas is higher than the calorific value of the blast furnace shut-off gas recovered by the gas recovery pipe 91.

[0040] It is easy to understand that the ejector 2 has a shut-off gas inlet and an ejection medium inlet. The shut-off gas inlet is connected to the blast furnace's gas outlet, and the ejection medium inlet is connected to the outlet of the ejection medium source 1. The ejection medium source 1 supplies high-pressure ejection medium to the ejector 2 via the ejection medium inlet, providing a power source for the ejector 2 to recover the shut-off gas from the blast furnace. The type of ejection medium is not limited; for example, it can be nitrogen. Under the action of high-pressure nitrogen, the shut-off gas from the blast furnace is ejected and recovered, and then delivered to the user-side low-pressure gas delivery main 92 via the gas recovery pipe 91 for use by the user. During the shut-off period of the blast furnace, the calorific value of the shut-off gas is low. When the ejection medium is nitrogen, the calorific value of the shut-off gas is easily reduced. The blast furnace air-off gas recovery system provided in the embodiment of the present application is provided with a high calorific value gas source 3. The high calorific value gas source 3 can be used to supply high calorific value gas to the gas recovery pipe 91 through the gas supply main 93. Here, the high calorific value gas refers to a gas with a calorific value higher than that of the blast furnace air-off gas, which can be mixed with the blast furnace air-off gas in the gas recovery pipe 91, thereby reducing the influence of the induced nitrogen on the calorific value of the blast furnace air-off gas, improving the calorific value of the recovered blast furnace air-off gas, stabilizing the calorific value of the gas at the source of the blast furnace gas source, and making the calorific value of the blast furnace air-off gas supplied to the user through the low-pressure gas transmission main 92 higher, so that the user's burner is not easy to go out, and the blast furnace air-off gas is not easy to overflow from the burner, thereby improving the safety of blast furnace air-off gas recovery and use.

[0041] In the embodiment provided in the present application, the blast furnace air-off gas recovery system further includes a first regulating valve 4 ; the first regulating valve 4 is provided on the gas supply main pipe 93 , and the first regulating valve 4 is used to regulate the flow of high calorific value gas supplied by the gas supply main pipe 93 .

[0042] In this way, the flow of high calorific value gas in the gas supply main 93 can be adjusted by adjusting the opening of the first regulating valve 4, thereby controlling the degree to which the high calorific value gas increases the calorific value of the blast furnace shut-off gas in the gas recovery pipe 91, which is highly flexible.

[0043] In the embodiment provided in the present application, the blast furnace shut-off gas recovery system also includes a gas calorific value analyzer 5; the gas calorific value analyzer 5 is arranged in the gas recovery pipe 91 and is located downstream of the connection between the gas supply main 93 and the gas recovery pipe 91. The gas calorific value analyzer 5 is used to measure the calorific value of the gas in the gas recovery pipe 91.

[0044] In this way, the gas calorific value analyzer 5 can be used to measure the calorific value of the mixed gas of blast furnace air-off gas and high calorific value fuel gas in the gas recovery pipe 91 in real time, and the opening of the first regulating valve 4 can be accurately adjusted according to the measured calorific value data, so as to accurately control the flow of high calorific value fuel gas in the gas supply main pipe 93, so as to accurately control the degree to which the calorific value of the blast furnace air-off gas in the gas recovery pipe 91 is increased by the high calorific value fuel gas, so that the calorific value controllability of the blast furnace air-off gas sent into the low-pressure gas transmission main pipe 92 is improved, and the safety of use is more controllable.

[0045] In the embodiment provided in the present application, the gas supply main pipe 93 is provided with a shut-off valve 7, which is used to conduct or shut off the gas supply main pipe 93. During use, the shut-off valve 7 can be used to timely conduct the gas supply main pipe 93, so that the high calorific value gas source 3 can promptly supply high calorific value gas to the gas recovery pipe 91 through the gas supply main pipe 93, thereby improving the timeliness of the calorific value adjustment of the blast furnace off-air gas in the gas recovery pipe 91, thereby further improving the safety of the recovery and use of the blast furnace off-air gas. The shut-off valve 7 can also be used to timely shut off the gas supply main pipe 93, thereby promptly shutting off the high calorific value gas supply of the high calorific value gas source 3, thereby avoiding waste of high calorific value gas.

[0046] like Figure 1 As shown, in the embodiment of the present application, the ejection medium source 1 and the ejector 2 are connected through an ejection medium supply pipe 94, and the ejection medium supply pipe 94 is provided with a second regulating valve 6, which is used to adjust the flow rate of the ejection medium supplied by the ejection medium supply pipe 94.

[0047] When in use, the flow rate of the ejection medium supplied from the ejection medium source 1 to the ejector 2 through the ejection medium supply pipe 94 can be adjusted by adjusting the opening of the second regulating valve 6, thereby controlling the rate at which the ejector 2 ejects the blast furnace's rest gas, thereby achieving the controllability of the blast furnace's rest gas recovery and utilization process.

[0048] In the embodiment provided in the present application, the blast furnace air-off gas recovery system also includes a controller (not shown in the figure); the controller is respectively connected to the first regulating valve 4, the gas calorific value analyzer 5, the shut-off valve 7 and the second regulating valve 6, and the controller is used to control the shut-off valve 7 and the first regulating valve 4 to open according to the opening signal of the second regulating valve 6, and to control the shut-off valve 7 and the first regulating valve 4 to close according to the closing signal of the second regulating valve 6. The controller is used to control the opening of the first regulating valve 4 according to the calorific value data measured by the gas calorific value analyzer 5.

[0049] During use, the controller can obtain the opening information of the second regulating valve 6. When the opening of the second regulating valve 6 is greater than 0, that is, when the second regulating valve 6 is opened, the ejection medium source 1 starts to supply the ejection medium to the ejector 2, and the ejection medium starts to eject the rest gas in the blast furnace. Within a certain period of time thereafter, the shut-off valve 7 and the first regulating valve 4 can be controlled to open, and the opening of the first regulating valve 4 is adjusted to be greater than 0, so that the high calorific value gas source 3 starts to supply high calorific value gas to the gas recovery pipe 91 through the gas supply main pipe 93, and the adjustment work of the calorific value of the blast furnace rest gas in the gas recovery pipe 91 begins. When the opening of the second regulating valve 6 is 0, that is, when the second regulating valve 6 is closed, the ejector 2 stops ejecting the blast furnace rest gas, and the shut-off valve 7 and the first regulating valve 4 can be controlled to close, that is, the opening of the first regulating valve 4 is adjusted to 0, thereby completing the adjustment work of the calorific value of the blast furnace rest gas by the high calorific value gas source 3. In this way, the interlocking control of the blast furnace off-air gas injection work and the calorific value adjustment work can be achieved, which not only can realize the timely adjustment of the calorific value of the blast furnace off-air gas to further improve the safety of the blast furnace off-air gas recovery and use, but also can realize the timely stop of the high calorific value gas supply, avoid the waste of high calorific value gas, and reduce the cost of blast furnace off-air gas recovery.

[0050] Not only that, the controller can also automatically collect the calorific value data measured by the gas calorific value analyzer 5, and automatically control the opening of the first regulating valve 4 according to the collected calorific value data, so as to realize the interlocking control of the calorific value of the blast furnace off-air gas and the high calorific value gas supply flow, thereby improving the efficiency of the calorific value regulation of the blast furnace off-air gas, and further improving the safety of the blast furnace off-air gas used by the user end.

[0051] Please refer to Figure 2 , Figure 2 for Figure 1 Schematic diagram of the structure of the connection between the ring pipe and the gas recovery pipe.

[0052] In actual configuration, the method in which the gas supply main pipe 93 supplies the high calorific value gas to the gas recovery pipe 91 is not limited.

[0053] In the embodiment provided herein, the gas supply main 93 and the gas recovery pipe 91 are connected via a gas mixing device 8. Specifically, the gas mixing device 8 is a device capable of evenly mixing the high-calorific value gas supplied by the gas supply main 93 with the blast furnace air gas recovered by the gas recovery pipe 91. This allows the high-calorific value gas supplied by the gas supply main 93 to be evenly mixed with the blast furnace air gas recovered by the gas recovery pipe 91 using the gas mixing device 8. This ensures a stable composition of the blast furnace air gas entering the low-pressure gas delivery main 92, further enhancing the safety of blast furnace air gas recovery and utilization.

[0054] During specific settings, the mixing device 8 does not limit the form of mixing the high calorific value fuel gas and the blast furnace air gas. For example, the high calorific value fuel gas and the blast furnace air gas can be introduced into the mixing device 8 for mixing, or the high calorific value fuel gas can be evenly dispersed into the gas recovery pipe 91 through the mixing device 8 for mixing.

[0055] As an alternative, please combine Figure 2 It is understood that the gas mixing device 8 can be a device that allows high calorific value gas to evenly enter the gas recovery pipe 91, and the specific mixing is carried out in the gas recovery pipe 91. The gas mixing device 8 can be an annular tube, which can be sleeved on the circumferential outer side of the gas recovery pipe 91. The annular tube can be provided with a first gas inlet 8a and several gas outlets 8b. The gas recovery pipe 91 can be provided with several second gas inlets 91a. The several second gas inlets 91a and the several gas outlets 8b can be the same in number and correspond one to one. The gas outlet 8b and the second gas inlet 91a can be connected through a gas supply branch pipe 95.

[0056] During use, the high calorific value gas in the gas supply main pipe 93 enters the annular pipe through the first gas inlet 8a of the annular pipe, and then enters the corresponding gas supply branch pipe 95 from each gas outlet 8b, and then enters the gas recovery pipe 91 through the second gas inlet 91a from the gas supply branch pipe 95. Since the gas recovery pipe 91 is provided with several, that is, more than two second gas inlets 91a, the high calorific value gas can enter the gas recovery pipe 91 from at least two directions, so that it can be evenly mixed with the blast furnace air-off gas recovered by injection from the inside of the gas recovery pipe 91, so that the composition of the blast furnace air-off gas is stable, and the effect of the high calorific value gas on adjusting the calorific value of the blast furnace air-off gas is improved, so that the calorific value of the blast furnace air-off gas is relatively stable, which can improve the safety of the recovery and use of the blast furnace air-off gas, save the use of high calorific value gas, and reduce the cost of the recovery and use of the blast furnace air-off gas.

[0057] As another optional solution, the gas mixing device 8 can be in the form of a mixing chamber, and the specific mixing operation is carried out in the gas mixing device 8. The mixing chamber can have a blast furnace off-air gas inlet, a high calorific value fuel gas inlet and a mixed gas outlet. The gas recovery pipe 91 can include an upstream pipe section and a downstream pipe section. The upstream pipe section can be connected to the gas outlet of the ejector 2 at one end and the blast furnace off-air gas inlet of the mixing chamber at the other end. The downstream pipe section can be connected to the mixed gas outlet of the mixing chamber at one end and the low-pressure gas delivery main 92 at the other end. The gas outlet of the gas supply main 93 can be connected to the high calorific value fuel gas inlet of the mixing chamber. The gas supply main 93 can be connected to the high calorific value fuel gas inlet of the mixing chamber. The high calorific value fuel gas supplied by 93 can be mixed in the mixing chamber with the blast furnace air-off gas recovered by the upstream pipe section of the above-mentioned gas recovery pipe 91 to obtain a mixed gas. The mixed gas can be transported to the low-pressure gas transportation main pipe 92 through the downstream pipe section of the gas recovery pipe 91. In this way, the uniformity of the mixing of the high calorific value fuel gas and the blast furnace air-off gas is achieved, and the composition of the blast furnace air-off gas is relatively stable, thereby improving the effect of the high calorific value fuel gas on adjusting the calorific value of the blast furnace air-off gas, making the calorific value of the blast furnace air-off gas relatively stable, and improving the safety of the recovery and use of the blast furnace air-off gas, and saving the use of the high calorific value fuel gas, thereby reducing the cost of the recovery and use of the blast furnace air-off gas.

[0058] In specific configuration, the arrangement of the gas outlet 8b on the ring pipe is not limited.

[0059] In the embodiment provided in the present application, a plurality of gas outlets 8b are evenly spaced along the circumference of the inner ring wall of the annular tube, and a plurality of second gas inlets 91a are evenly spaced along the circumference of the gas recovery pipe 91. In this way, after the high calorific value gas in the gas supply main pipe 93 enters the annular tube, it can enter the gas recovery pipe 91 more evenly from all directions, thereby further improving the mixing effect of the high calorific value gas and the blast furnace air gas, and making the calorific value of the blast furnace air gas mixed with the high calorific value gas more stable.

[0060] In specific configuration, the number of the gas outlets 8b on the ring pipe is not limited, for example, it can be two, or it can be three or more.

[0061] As an alternative, please combine Figure 2 It is understood that there are four gas outlets 8b on the ring pipe, and correspondingly, there are also four second gas inlets 91a of the gas supply branch pipe 95 and the gas recovery pipe 91. The four gas outlets 8b are connected to the second gas inlet 91a through the four gas supply branch pipes 95 respectively. In this way, the structure is simple and the gas mixing effect is better.

[0062] In actual settings, the specific type of high calorific value gas is not limited. For example, it can be coke oven gas, natural gas, or liquefied petroleum gas. Of course, it can also be a mixture of any two or three of these three gases.

[0063] In the embodiment provided in the present application, the blast furnace shut-off gas recovery system also includes a gravity dust collector and a bag dust collector; the air inlet of the ejector 2 and the air outlet of the blast furnace can be connected through a gas ejector pipe 96, and the gravity dust collector and the bag dust collector can be arranged in sequence on the gas ejector pipe 96 along the flow direction of the blast furnace shut-off gas. In this way, the gravity dust collector and the bag dust collector can be used to remove dust from the shut-off gas flowing out of the blast furnace in sequence, realizing double dust removal with better dust removal effect, which can relatively guarantee the purity of the blast furnace shut-off gas subsequently supplied to users and improve the safety of the blast furnace shut-off gas use process.

[0064] The working principle of the blast furnace off-gas gas recovery system provided by the above embodiment of the present application is described below with reference to the accompanying drawings:

[0065] The controller can first control the second regulating valve 6 on the ejection medium supply pipe 94 to open, and the ejection medium source 1 supplies high-pressure ejection medium to the ejector 2 through the ejection medium supply pipe 94. The ejector 2 begins to use the high-pressure ejection medium to eject the blast furnace air gas and sends the ejected blast furnace air gas to the gas recovery pipe 91.

[0066] After receiving the signal for the second regulating valve 6 to open, the controller can control the shut-off valve 7 and the first regulating valve 4 to open in sequence. The high calorific value gas source 3 supplies high calorific value gas to the gas recovery pipe 91 via the gas supply main pipe 93. The high calorific value gas first enters the ring pipe and then evenly enters the gas recovery pipe 91 via the gas supply branch pipes 95. It is then evenly mixed with the blast furnace off-air gas inside the gas recovery pipe 91 to form a mixed gas. The composition of the mixed gas is relatively stable, and thus the calorific value is relatively stable. The mixed gas is then continuously transported through the gas recovery pipe 91 to the low-pressure gas transport main pipe 92 at the user end for use by the user.

[0067] During this process, the gas calorific value analyzer 5 can measure the calorific value of the above-mentioned mixed gas in the gas recovery pipe 91 in real time, and transmit the measured calorific value data to the controller. The controller can then adjust the opening of the first regulating valve 4 in real time according to the calorific value data. When the calorific value of the mixed gas is lower than the preset calorific value threshold, the opening of the first regulating valve 4 can be increased. When the calorific value of the mixed gas is higher than the preset calorific value threshold, the opening of the first regulating valve 4 can be decreased.

[0068] In the above process, since the second regulating valve 6, the shut-off valve 7 and the first regulating valve 4 are interlocked, when the blast furnace off-air gas starts to be injected, high calorific value fuel gas can be mixed into the gas recovery pipe 91 in time to quickly stabilize the calorific value of the blast furnace off-air gas in the gas recovery pipe 91, and the supply of high calorific value fuel gas flow can be adjusted in real time according to the real-time measured calorific value data of the blast furnace off-air gas, so that the calorific value of the blast furnace off-air gas can be adjusted in time, so that the calorific value of the blast furnace off-air gas can be adjusted in time and accurately. In this way, the response is fast and timely, which can relatively reduce the hidden dangers of burner flameout of downstream heating furnace users and improve the safety of blast furnace off-air gas recovery and use.

[0069] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only intended to help understand the device and its core concept of this application. It should be noted that for those skilled in the art, without departing from the principles of this application, various improvements and modifications can be made to this application, and such improvements and modifications also fall within the scope of protection of the claims of this application.

Claims

1. A blast furnace off-air gas recovery system, comprising an ejector medium source (1) and an ejector (2), wherein the ejector (2) is connected to the blast furnace and the ejector medium source (1) respectively, and the gas outlet of the ejector (2) is connected to a low-pressure gas delivery main pipe (92) via a gas recovery pipe (91), characterized in that: The blast furnace off-air gas recovery system further includes a high calorific value fuel gas source (3); The high calorific value fuel gas source (3) is connected to the gas recovery pipe (91) via a gas supply main pipe (93). The high calorific value fuel gas source (3) is used to supply high calorific value fuel gas to the gas recovery pipe (91). The calorific value of the high calorific value fuel gas is higher than the calorific value of the blast furnace off-gas gas recovered by the gas recovery pipe (91).

2. The blast furnace off-gas gas recovery system according to claim 1, characterized in that: The blast furnace off-air gas recovery system further includes a first regulating valve (4); The first regulating valve (4) is provided on the gas supply main pipe (93), and the first regulating valve (4) is used to regulate the flow rate of the high calorific value gas supplied by the gas supply main pipe (93).

3. The blast furnace off-gas gas recovery system according to claim 2, characterized in that: The blast furnace off-air gas recovery system further includes a gas calorific value analyzer (5); The coal gas calorific value analyzer (5) is provided in the coal gas recovery pipe (91) and is located downstream of the connection point between the gas supply main pipe (93) and the coal gas recovery pipe (91). The coal gas calorific value analyzer (5) is used to measure the calorific value of the gas in the coal gas recovery pipe (91).

4. The blast furnace off-gas gas recovery system according to claim 3, characterized in that: The gas supply main pipe (93) is provided with a shut-off valve (7), and the shut-off valve (7) is used to open or shut off the gas supply main pipe (93).

5. The blast furnace off-gas gas recovery system according to claim 4, characterized in that: The ejection medium source (1) and the ejector (2) are connected via an ejection medium supply pipe (94). The ejection medium supply pipe (94) is provided with a second regulating valve (6). The second regulating valve (6) is used to regulate the flow rate of the ejection medium supplied by the ejection medium supply pipe (94).

6. The blast furnace off-gas gas recovery system according to claim 5, characterized in that: The blast furnace off-air gas recovery system also includes a controller; The controller is connected to the first regulating valve (4), the coal gas calorific value analyzer (5), the shut-off valve (7) and the second regulating valve (6) respectively. The controller is used to control the shut-off valve (7) and the first regulating valve (4) to open according to the opening signal of the second regulating valve (6), and to control the shut-off valve (7) and the first regulating valve (4) to close according to the closing signal of the second regulating valve (6). The controller is used to control the opening degree of the first regulating valve (4) according to the calorific value data measured by the coal gas calorific value analyzer (5).

7. The blast furnace off-gas gas recovery system according to any one of claims 1 to 5, characterized in that: The gas supply main pipe (93) and the coal gas recovery pipe (91) are connected via a gas mixing device (8).

8. The blast furnace off-gas gas recovery system according to claim 7, characterized in that: The gas mixing device (8) is an annular tube, which is sleeved on the circumferential outer side of the gas recovery pipe (91). The annular tube is provided with a first gas inlet (8a) and a plurality of gas outlets (8b). The gas recovery pipe (91) is provided with a plurality of second gas inlets (91a). The number of the plurality of second gas inlets (91a) and the plurality of gas outlets (8b) are the same and correspond one to one. The gas outlets (8b) and the second gas inlets (91a) are connected via a gas supply branch pipe (95).

9. The blast furnace off-gas gas recovery system according to claim 8, characterized in that: A plurality of the gas outlets (8b) are evenly spaced along the circumference of the inner ring wall of the annular tube, and a plurality of the second gas inlets (91a) are evenly spaced along the circumference of the gas recovery pipe (91).

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