Converter gas recovery system and method

Abstract

The invention relates to a converter gas recovery system which comprises a first cooling flue used for being connected with a converter, the first cooling flue is provided with a first gas outlet and a second gas outlet, the first gas outlet is connected with a gas treatment mechanism, and the second gas outlet is connected with a gas waste heat recovery mechanism. And valve control units are respectively arranged at the first gas outlet and the second gas outlet. In addition, the invention also provides a converter gas recovery method implemented based on the converter gas recovery system. According to the system, the converter gas can enter the gas treatment mechanism to be treated and can also enter the gas waste heat recovery mechanism to be treated, the process flexibility is high, the treatment effect of the converter gas can be guaranteed, and the reliability and safety of converter gas treatment are improved; the coal gas treatment mechanism and the coal gas waste heat recovery mechanism can be standby for each other, and when one mechanism is not used, the other mechanism can be switched for treatment, so that the coal gas treatment mechanism and the coal gas waste heat recovery mechanism are convenient to overhaul and maintain, and the stability of converter steelmaking production is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of converter production, and in particular relates to a converter gas recovery system and a converter gas recovery method implemented based on the converter gas recovery system. Background Art

[0002] At present, the high-temperature coal gas produced by converter steelmaking is mainly recovered through the vaporization cooling flue for waste heat recovery. Generally, the gas temperature at the outlet of the vaporization cooling flue is in the range of 800-900°C. After the outlet of the vaporization cooling flue, there are two methods to cool and dedust the converter gas: wet dust removal (OG method) and dry dust removal (LT method). The cooling principle is to directly mix water or water mist with the high-temperature converter gas for cooling. These two methods not only consume water and electricity, but also cause waste of converter gas waste heat resources below 800-900°C. In addition, the current converter gas recovery generally adopts a single process with poor process flexibility. Once the recovery system equipment needs to be overhauled and maintained, the converter may need to cooperate to stop smelting, affecting the normal production of the converter. Summary of the invention

[0003] The present invention relates to a converter gas recovery system and a converter gas recovery method implemented based on the converter gas recovery system, which can at least solve some defects of the prior art.

[0004] The present invention relates to a converter gas recovery system, comprising a first cooling flue for connecting to a converter, wherein the first cooling flue has a first gas outlet and a second gas outlet, the first gas outlet is connected to a gas processing mechanism, the second gas outlet is connected to a gas waste heat recovery mechanism, and valve control units are respectively provided at the first gas outlet and the second gas outlet.

[0005] As one of the embodiments, two groups of valve control units both include valve seats, and the two share a group of gate plate assemblies, wherein the gate plate assembly includes a blind plate and an orifice plate, wherein the orifice plate is a gate plate with a through hole, and the blind plate is selectively inserted in one of the valve seats, and the orifice plate is inserted in the other valve seat; the system is also configured with a blind plate switching actuator for swapping the positions of the blind plate and the orifice plate.

[0006] As one of the implementation modes, the coal gas waste heat recovery mechanism includes a waste heat boiler, and a dust collector is connected to the flue gas inlet side of the waste heat boiler.

[0007] As one of the implementation modes, the waste heat boiler includes a first return boiler, and a longitudinal flushing heating surface is adopted in the first return boiler.

[0008] As one of the implementation modes, the waste heat boiler further includes a second return boiler, in which a plurality of convection evaporators are arranged in sequence from bottom to top, wherein the heating surface of the convection evaporator is a transverse flushing heating surface.

[0009] As one of the implementation modes, the coal gas waste heat recovery mechanism further includes a second cooling flue, and the second cooling flue is respectively connected to the second coal gas outlet and the dust collector.

[0010] As one of the implementation modes, the second cooling flue is arranged obliquely, and its smoke inlet is located above its smoke outlet.

[0011] As one of the implementation modes, the second cooling flue or the dust collector is provided with an admixture adding mechanism for adding admixture into the coal gas, and the added admixture is a substance capable of reducing the viscosity of dust in the coal gas.

[0012] The present invention also relates to a converter gas recovery method, which is implemented based on the above converter gas recovery system, and the method specifically comprises:

[0013] The two groups of valve control units are controlled to allow the converter gas to selectively enter the gas processing mechanism or the gas waste heat recovery mechanism for processing.

[0014] As one of the implementation methods, when the converter gas enters the gas waste heat recovery mechanism for processing,

[0015] The converter gas first passes through the first cooling flue, and the outlet gas temperature of the first cooling flue is reduced to 800-900°C;

[0016] The converter gas then passes through the second cooling flue, and the outlet gas temperature of the first cooling flue is reduced to 500-700°C;

[0017] Subsequently, the converter gas is processed in turn by a dust collector and a waste heat boiler.

[0018] The present invention has at least the following beneficial effects:

[0019] In the present invention, the converter gas can enter the gas treatment mechanism for treatment, and can also enter the gas waste heat recovery mechanism for treatment. The process has high flexibility, can ensure the treatment effect of the converter gas, and improve the reliability and safety of the converter gas treatment; the gas treatment mechanism and the gas waste heat recovery mechanism can serve as backup for each other. When one of the mechanisms is out of use, it can be switched to the other mechanism for treatment, thereby facilitating the inspection and maintenance of the gas treatment mechanism and the gas waste heat recovery mechanism, and ensuring the stability of the converter steelmaking production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of a converter gas recovery system provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the structure of a waste heat boiler provided in an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the structure of a first return boiler provided in an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the structure of a three-way flue provided in an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the structure of a circular switching track provided in an embodiment of the present invention;

[0026] Figure 6 and Figure 7 A schematic diagram of the structure of a water-cooled blind plate provided in an embodiment of the present invention;

[0027] Figure 8 It is a structural schematic diagram of a blind plate body of a water-cooled blind plate;

[0028] Fig. 9 A schematic diagram of the structure of a water-cooling orifice plate provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on 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.

[0030] Embodiment 1

[0031] like Figure 1 An embodiment of the present invention provides a converter gas recovery system, comprising a first cooling flue 1 for connecting to a converter, wherein the first cooling flue 1 has a first gas outlet and a second gas outlet, the first gas outlet is connected to a gas processing mechanism, the second gas outlet is connected to a gas waste heat recovery mechanism, and valve control units are respectively provided at the first gas outlet and the second gas outlet.

[0032] In the above system, the converter gas can enter the gas treatment mechanism for treatment, and can also enter the gas waste heat recovery mechanism for treatment. The process has high flexibility, can ensure the treatment effect of the converter gas, and improve the reliability and safety of the converter gas treatment; the gas treatment mechanism and the gas waste heat recovery mechanism can serve as backup for each other. When one of the mechanisms is out of service, it can be switched to the other mechanism for treatment. This facilitates the inspection and maintenance of the gas treatment mechanism and the gas waste heat recovery mechanism, and ensures the stability of the converter steelmaking production.

[0033] The above system may be newly built or may be formed by modifying an existing system. For example, a gas waste heat recovery mechanism may be newly added on the basis of an existing gas processing mechanism.

[0034] In one embodiment, if Figure 1 The gas processing mechanism includes an evaporative cooler 7, and the smoke inlet of the evaporative cooler 7 is connected to the above-mentioned first gas outlet, including but not limited to being connected to the evaporative cooler 7 and the first gas outlet respectively through the tail flue.

[0035] Furthermore, an expansion joint is provided between the tail flue and the evaporative cooler 7, which can better compensate for pipeline deformation, eliminate internal stress of the pipeline, etc.

[0036] Furthermore, a first dust collector (shown in the figure, not labeled) is connected to the smoke outlet side of the evaporative cooler 7, and the first dust collector is connected to a downstream device through a first gas pipeline, and the downstream device may be a gas storage device, such as a gas cabinet, etc. A control valve such as a cut-off valve may be provided on the first gas pipeline. The first dust collector includes but is not limited to an inertial dust collector.

[0037] In one embodiment, if Figure 1 The gas waste heat recovery mechanism includes a waste heat boiler 6, which can recover part of the waste heat of the converter gas.

[0038] Furthermore, if Figure 1 The flue gas inlet side of the waste heat boiler 6 is connected to a second dust collector 5, which performs pre-dust removal on the converter gas, which can significantly reduce the dust content of the gas entering the waste heat boiler 6, reduce the ash load of the waste heat boiler 6, and effectively remove the fire carried in the gas, further improving the safety of the system. The second dust collector 5 includes but is not limited to an inertial dust collector, preferably a cyclone dust collector, which has a good dust removal effect and efficiency.

[0039] Among them, the above-mentioned second dust collector 5 can be equipped with cooling measures. For example, the dust collector adopts water-cooled walls, which can not only improve the service life of the dust collector, but also cool the converter gas and reduce the ash viscosity in the converter gas, thereby reducing the probability of sticky ash accumulation in the waste heat boiler 6.

[0040] In one embodiment, if Figure 1 The coal gas waste heat recovery mechanism also includes a second cooling flue 4, which is connected to the above-mentioned second coal gas outlet, and the waste heat boiler 6 is connected downstream of the second cooling flue 4. Specifically, when a second dust collector 5 is provided, the flue gas outlet end of the second cooling flue 4 is connected to the second dust collector 5. When the second dust collector 5 is not provided, the second cooling flue 4 can be directly connected to the waste heat boiler 6 (other facilities can be added between the two as needed).

[0041] The second cooling flue 4 can cool the converter gas, achieve effective cooling of the converter gas, and significantly reduce the probability of sticky ash accumulation in the waste heat boiler 6. At the same time, the second cooling flue 4 is also convenient for the arrangement of the gas waste heat recovery mechanism.

[0042] Preferably, if Figure 1 The second cooling flue 4 is arranged obliquely, and its flue gas inlet is located above its flue gas outlet. The inclined design of the second cooling flue 4 is conducive to the flow and removal of ash particles inside it; in particular, in the second cooling flue 4, the direction of coal gas flow is the same as that of ash particles, and the coal gas flow velocity in the second cooling flue 4 is relatively high, so the coal gas can carry ash particles and flow by itself, thereby avoiding ash accumulation in the second cooling flue 4.

[0043] Preferably, the inclination angle of the second cooling flue 4 relative to the horizontal plane is 30° to 80°.

[0044] More preferably, if Figure 1 The second cooling flue 4 includes a first inclined flue section 41 and a second inclined flue section 42. The second inclined flue section 42 is connected to the bottom of the first inclined flue section 41. The inclination angle of the first inclined flue section 41 relative to the horizontal plane (hereinafter referred to as the inclination angle) is different from the inclination angle of the second inclined flue section 42 relative to the horizontal plane; more specifically, the inclination angle of the first inclined flue section 41 is greater than the inclination angle of the second inclined flue section 42. Based on this design, the large inclination angle design of the first inclined flue section 41 is conducive to driving away dust through coal gas; the two-stage flue section design with different inclination angles increases the flue gas turbulence to a certain extent, thereby improving the heat exchange effect between the coal gas and the flue wall. Moreover, the two-stage flue design can reduce the concentration of thermal stress in the flue, extend the service life of the flue, and make the flue more flexible to adapt to complex spaces, which is conducive to the layout of waste heat recovery equipment. In one embodiment, the inclination angle of the first inclined flue section 41 is 50° to 80°, and the inclination angle of the second inclined flue section 42 is 30° to 60°.

[0045] In the above system, through the first cooling flue 1 + the second cooling flue 4 + (water-cooled second dust collector 5) + waste heat boiler 6, a wide range of waste heat recovery of converter gas can be achieved, which greatly avoids the waste of sensible heat of converter gas.

[0046] Among them, preferably, the first cooling flue 1 adopts a vaporization cooling flue.

[0047] Preferably, the outlet gas temperature of the first cooling flue 1 is reduced to 800-900°C, and further, the outlet gas temperature of the first cooling flue 1 is controlled at about 850°C.

[0048] Among them, preferably, the second cooling flue 4 adopts a vaporization cooling flue.

[0049] Preferably, the outlet gas temperature of the second cooling flue 4 is reduced to 500-700°C.

[0050] In one embodiment, if Figure 1 The end of the first cooling flue 1 adopts a three-way flue 2, and the three-way flue 2 has a gas inlet and two gas outlets, and the two gas outlets are respectively constituted as a first gas outlet and a second gas outlet.

[0051] Optionally, the valve control unit adopts a plug valve 3 , including but not limited to a blind plate valve 3 .

[0052] Preferably, explosion relief valves are installed at the three-way flue 2, the waste heat boiler 6 and other locations, so that in case of a gas explosion, the explosion can be relieved in a timely and effective manner to ensure the safety of personnel and equipment.

[0053] Preferably, a cleaning device is provided in the second cooling flue 4, the waste heat boiler 6 and other parts to clean the heating surface regularly to ensure that the heating surface is clean and unobstructed; the cleaning method can adopt one or a combination of nitrogen shock wave, acetylene shock wave, high-efficiency sound wave, steam soot blowing and other cleaning methods.

[0054] In one embodiment, an admixture adding mechanism is provided on the second cooling flue 4 or the second dust collector 5, which is used to add admixtures to the coal gas. The added admixtures are substances that can reduce the viscosity of dust in the coal gas, including but not limited to kaolin or quartz sand. Kaolin, quartz sand, etc. are high melting point substances, which are in solid particle state at the waste heat recovery temperature. After mixing with converter ash, the overall ash melting point can be increased, thereby reducing the ash viscosity. Through the above-mentioned method, the situation of adhesive ash accumulation in the subsequent waste heat boiler 6 can be greatly alleviated, and the reliability of system operation can be improved. Among them, it is preferred to set an admixture adding mechanism on the second cooling flue 4, which is conducive to the full reaction of the admixture and the coal gas, especially to the removal of the ash particles after the reaction in the second dust collector 5, and reduce the ash load of the waste heat boiler 6. When the above-mentioned admixture is added in the form of powder spraying, a better reaction effect and efficiency can be achieved. Therefore, the above-mentioned admixture adding mechanism can include a powder spraying gun arranged on the second cooling flue 4 / second dust collector 5, and the powder spraying gun is equipped with a powder bin and a pressure medium supply mechanism. The pressure medium is preferably an inert gas such as nitrogen.

[0055] Embodiment 2

[0056] The embodiment of the present invention provides a waste heat boiler 6, wherein the waste heat boiler 6 can be used in the above-mentioned embodiment 1.

[0057] like Figure 2 The waste heat boiler 6 includes a first return boiler 61, a second return boiler 62 and a settling chamber 63. The first return boiler 61 and the second return boiler 62 are both erected on the settling chamber 63 and are both connected to the inner cavity of the settling chamber 63. A smoke inlet is provided at the top of the first return boiler 61, and a smoke outlet is provided at the top of the second return boiler 62.

[0058] It can be seen that the waste heat boiler 6 adopts a double-return structure design, and the flue gas is introduced from the flue gas inlet at the top of the first return boiler 61. After the flue gas exchanges heat with the heating surface in the first return boiler 61, it enters the settling chamber 63 from the first return boiler 61, and then enters the second return boiler 62. After exchanging heat with the heating surface in the second return boiler 62, it is discharged from the flue gas outlet at the top of the second return boiler 62. Among them, the flue gas runs from top to bottom in the first return boiler 61, and runs from bottom to top in the second return boiler 62.

[0059] Among them, preferably, in the first return boiler 61, a longitudinal flushing heating surface 611 is adopted, that is, the flue gas longitudinally flushes its heating surface, which can effectively alleviate the degree of ash accumulation and reduce the occurrence of ash accumulation while recovering the waste heat of the flue gas.

[0060] In one embodiment, if Figure 2 and Figure 3The longitudinal flushing heating surface 611 includes a plurality of longitudinal evaporation tubes 6111, the axes of the longitudinal evaporation tubes 6111 are parallel to the vertical direction, and the two ends of the longitudinal evaporation tubes 6111 are respectively connected with bridge tubes 6112, and the bridge tubes 6112 extend outside the furnace shell to connect with corresponding medium tubes.

[0061] Among them, preferably, the medium flows in the longitudinal evaporation tube 6111 from bottom to top, which is opposite to the flue gas flow in the first return boiler 61, and can improve the heat exchange effect; the bridge tube 6112 at the bottom end of the longitudinal evaporation tube 6111 is used to connect the water inlet pipe, and the bridge tube 6112 at the top end of the longitudinal evaporation tube 6111 is used to connect the return pipe.

[0062] Among them, preferably, at least some of the bridge tubes 6112 at the top ends of the longitudinal evaporator tubes 6111 are connected to the same distribution header 6113, and at least some of the bridge tubes 6112 at the bottom ends of the longitudinal evaporator tubes 6111 are connected to the same distribution header 6113. This facilitates centralized management of water inlet and return water, reduces the number of on-site pipelines, and simplifies the layout.

[0063] Among them, preferably, Figure 3 , each longitudinal evaporation tube 6111 is distributed to form a plurality of evaporation tube groups; in each evaporation tube group, each longitudinal evaporation tube 6111 is distributed in the same vertical plane and is arranged in sequence from the inner wall of the furnace shell to the axis of the furnace shell, and, from the inner wall of the furnace shell to the axis of the furnace shell, the top position of each longitudinal evaporation tube 6111 gradually increases, and the bottom position of each longitudinal evaporation tube 6111 gradually decreases. This method facilitates the arrangement of each longitudinal evaporation tube 6111, and can arrange as many longitudinal evaporation tubes 6111 as possible, thereby ensuring the heat exchange effect with the flue gas; it can be understood that the closer to the center of the furnace shell, the longer the heat exchange stroke of the longitudinal evaporation tube 6111, which can also better match the flue gas flow field in the first return boiler 61, and correspondingly improve the heat exchange effect with the flue gas. Optionally, the same evaporation tube group shares a water inlet distribution header 6113 and a return water distribution header 6113.

[0064] The longitudinal heat exchange tube can be a plain tube or a finned tube.

[0065] The bridge tube 6112 can be arranged horizontally (with the axis parallel to the horizontal plane) or tilted (with the axis tilted relative to the horizontal plane). When the bridge tube 6112 is tilted, for example, the top of the longitudinal evaporation tube 6111 extends obliquely upward to form a top bridge tube 6112, and the bottom of the longitudinal evaporation tube 6111 extends obliquely downward to form a bottom bridge tube 6112, the flushing of flue gas is helpful to alleviate the dust accumulation on the bridge tube 6112.

[0066] The first return boiler 61 preferably adopts a membrane water-cooled wall, which can ensure the recovery effect and efficiency of flue gas waste heat in the combination of the longitudinal flushing heating surface 611 and the water-cooled wall.

[0067] In one embodiment, if Figure 2 A plurality of convection evaporators 621 are arranged in sequence from bottom to top in the second return boiler 62, wherein preferably, the flue gas horizontally flushes the heating surface of the convection evaporator 621. Specifically, the convection evaporator 621 includes a plurality of horizontal evaporation tubes, and the axis of the horizontal evaporation tubes is preferably parallel to the horizontal plane.

[0068] When used for gas treatment in the above-mentioned embodiment 1, after the previous multi-stage cooling, the gas temperature entering the second return boiler 62 is relatively low, and the ash accumulation formed in the second return boiler 62 is mainly loose ash accumulation, which is relatively easy to remove; and the use of horizontal evaporation tubes can improve the heat exchange effect and efficiency with the gas, and even if ash accumulation occurs, it is not easy to cause ash blockage. Preferably, the gas temperature at the outlet side of the first return boiler 61 is below the cohesive ash temperature (defined as the gas temperature that is easy to form cohesive ash), which can ensure the normal operation of the second return boiler 62. Specifically, the gas temperature at the outlet side of the first return boiler 61 drops to 400-600°C.

[0069] The transverse evaporation tube can be a plain tube or a finned tube.

[0070] Among them, a plurality of transverse evaporation tubes may be arranged on the cross section of the convection evaporator 621; the vertical arrangement of the transverse evaporation tubes may be in-line arrangement, staggered arrangement or a combination of the two arrangements.

[0071] Among them, the convection evaporators 621 at each stage can be connected in series (the inlet water flows from the top convection evaporator 621 to the lower convection evaporator 621 in sequence), or in parallel (the inlet and outlet water of each convection evaporator 621 are independent of each other), or some of the convection evaporators 621 can be connected in series.

[0072] More preferably, if Figure 2 In the second return boiler 62, at least one economizer 622 is arranged downstream of the last-stage convection evaporator 621. When there are multiple economizers 622, the economizers 622 are arranged in sequence from bottom to top.

[0073] Preferably, the flue gas flushes the heating surface of the economizer 622 laterally.

[0074] Optionally, the economizer 622 includes a plurality of serpentine evaporator tubes, which are arranged in a serpentine shape on the cross section of the economizer 622; the vertical arrangement of each serpentine evaporator tube may be in-line arrangement, staggered arrangement or a combination of the two arrangements.

[0075] The serpentine evaporation tube can be a plain tube or a finned tube.

[0076] Preferably, multiple soot blowers are arranged in the first return boiler 61 and the second return boiler 62 to clean the heating surface regularly to ensure that the heating surface is clean and unobstructed; the cleaning method can be one or a combination of nitrogen shock wave, acetylene shock wave, high-efficiency sound wave, steam soot blowing, etc. Further, detectors are arranged in the first return boiler 61 and the second return boiler 62. The detectors can be carbon monoxide concentration detectors and / or oxygen concentration detectors. The detectors are preferably interlocked with the soot blowers to achieve automatic control of soot blowing.

[0077] Optionally, both the first return boiler 61 and the second return boiler 62 are provided with inspection manholes.

[0078] The first return boiler 61 and the settling chamber 63, and the second return boiler 62 and the settling chamber 63 can be fixed by welding, flange fixing, or integral molding. The settling chamber 63 can play the role of inertial dust removal, further reducing the probability of dust accumulation and blockage of the waste heat boiler 6; in addition, the dust falling from the first return boiler 61 and the second return boiler 62 will enter the settling chamber 63, which is conducive to dust recovery.

[0079] Embodiment 3

[0080] The embodiment of the present invention provides a three-way flue 2, wherein the three-way flue 2 can be used in the above-mentioned embodiment 1.

[0081] like Figure 4 The three-way flue 2 includes a flue gas inlet section 21 and two flue gas outlet sections 22, wherein the flue gas inlet section 21 and the two flue gas outlet sections 22 are both in the form of vaporization cooling flues, that is, the flue gas inlet section 21 and the flue gas outlet section 22 are both surrounded by a plurality of vaporization cooling pipes to form corresponding flues.

[0082] In one embodiment, part of the vaporization cooling pipe of the smoke inlet section 21 is coupled with one of the smoke outlet sections 22 to form a first heating surface, and the rest of the vaporization cooling pipe of the smoke inlet section 21 is coupled with another smoke outlet section 22 to form a second heating surface; for example: the left half of the smoke inlet section 21 is coupled with the smoke outlet section 22 on its left side to form the first heating surface, and the right half of the smoke inlet section 21 is coupled with the smoke outlet section 22 on its right side to form the second heating surface. Based on the above design, the number of steam-water pipes can be reduced, which is convenient for on-site implementation.

[0083] For the convenience of description, the vaporization cooling pipeline of the smoke inlet section 21 is defined as the first cooling pipeline 211 , and the vaporization cooling pipeline of the smoke outlet section 22 is defined as the second cooling pipeline 221 .

[0084] For the coupling between the vaporization cooling pipes, the vaporization cooling pipes are connected to form a water path. For example, cooling water enters from one end of the first vaporization cooling pipe, passes through the first cooling pipe 211 and the coupled second vaporization cooling pipe in turn for heat exchange, and then is discharged from the second vaporization cooling pipe to form cooling return water.

[0085] Further preferably, each first cooling pipe 211 is coupled to a plurality of second cooling pipes 221, including but not limited to one first cooling pipe 211 coupled to two second cooling pipes 221. For a structure in which one first cooling pipe 211 is coupled to two second cooling pipes 221, preferably, as Figure 4 , a Y-shaped trousers tube 23 is used to complete the coupling, and the two trouser legs of the Y-shaped trousers tube 23 are respectively connected to the two second cooling pipes 221, and the other end of the Y-shaped trousers tube 23 is connected to the first cooling pipe 211. Based on the above structure, reliable coupling between the smoke inlet section 21 and the smoke outlet section 22 can be achieved, and a reasonable heating surface can be designed to ensure the vaporization cooling effect and heating uniformity of each part of the three-way flue 2.

[0086] Wherein, the adjacent Y-shaped trousers tubes 23 may be sealed by using a flat steel partition or the like.

[0087] The first heating surface is configured with one or more water inlet headers and one or more water return headers, preferably the number of water inlet headers and water return headers is the same and they are configured one by one. For example, in the structure where the left half of the smoke inlet section 21 is coupled with the smoke outlet section 22 on its left side to form the first heating surface, the first cooling pipes 211 in the upper half can share one water inlet header and the second cooling pipes 221 can share one water return header, and the first cooling pipes 211 in the lower half can share one water inlet header and the second cooling pipes 221 can share one water return header, and the two water inlet headers are connected to the same water inlet pipe, and the two water return headers are connected to the same water return pipe. The second heating surface can adopt the same water inlet and water return configuration.

[0088] In another embodiment, the following heating surface composition can be adopted: part of the vaporization cooling pipe of the smoke inlet section 21 is coupled with the lower half of one of the smoke outlet sections 22 to form a 1# heating surface, the remaining vaporization cooling pipe of the smoke inlet section 21 is coupled with the lower half of the other smoke outlet section 22 to form a 2# heating surface, and the upper halves of the two smoke outlet sections 22 are coupled to form a 3# heating surface.

[0089] Embodiment 4

[0090] This embodiment further optimizes the converter gas recovery system provided in the first embodiment. Specifically, the two groups of valve control units are further optimized as follows:

[0091] Both valve control units include valve seats, and they share a set of gate plate assemblies, the gate plate assembly includes a blind plate 30a and an orifice plate 30b, wherein the orifice plate 30b is a gate plate with a through hole, the blind plate 30a is selectively inserted in one of the valve seats, and the orifice plate 30b is inserted in the other valve seat. When the blind plate 30a is inserted in one of the valve seats, the valve control unit is in a closed state, and the other valve control unit is in an open state due to the orifice plate 30b at the valve seat; based on this scheme, the converter gas can only enter one of the gas processing mechanism and the gas waste heat recovery mechanism, and will not enter both mechanisms at the same time, thereby ensuring the reliability of system operation and avoiding the occurrence of misoperation. The blind plate 30a and the orifice plate 30b are switched to ensure the sealing of the first gas outlet and the second gas outlet.

[0092] When two mechanisms need to switch operation, for example, switching from the operation of the gas waste heat recovery mechanism to the operation of the gas processing mechanism, it is necessary to switch the insertion position of the blind plate 30a, that is, the blind plate 30a needs to be switched from the valve seat currently in the closed state to the valve seat currently in the open state. Accordingly, a blind plate switching actuator is provided.

[0093] like Figure 5 The blind plate switching actuator includes an annular switching track 8 and two sets of lifting devices movably arranged on the annular switching track 8, wherein the annular switching track 8 includes a first regular track section 81 located directly above the first gas outlet, a second regular track section 82 located directly above the second gas outlet, and a transfer track section connecting the first regular track section 81 and the second regular track section 82, the guiding direction of the first regular track section 81 is perpendicular to the axial direction of the first gas outlet, and the guiding direction of the second regular track section 82 is perpendicular to the axial direction of the second gas outlet.

[0094] The lifting device is used to lift the gate plate 30 at one of the gas outlets (the first gas outlet / the second gas outlet), and then move it to the other gas outlet on the annular switching track 8 for installation; and the annular switching track 8 can ensure the smoothness of the relative movement of the blind plate 30a and the orifice plate 30b, and the blind plate 30a and the orifice plate 30b can be moved synchronously to the target position for installation, thereby improving maintenance efficiency and saving maintenance time.

[0095] Preferably, if Figure 5 The transfer track segment includes two first extension track segments 83, two second extension track segments 84 and two relay track segments 85, wherein:

[0096] The two first extension track segments 83 are connected to the two ends of the first normal track segment 81 respectively, and the guiding directions of the two first extension track segments 83 are parallel to the guiding direction of the first normal track segment 81, so that the smoothness and reliability of replacing the gate plate 30 at the first gas outlet can be improved.

[0097] The two second extension track segments 84 are respectively connected to the two ends of the second main track segment 82, and the guiding directions of the two second extension track segments 84 are parallel to the guiding direction of the second main track segment 82, so that the smoothness and reliability of replacing the gate plate 30 at the second gas outlet can be improved.

[0098] The first extended track segment 83 and the second extended track segment 84 on the same side are connected by a relay track segment 85 .

[0099] Preferably, the sum of the lengths of the first main rail segment 81 and the two first extended rail segments 83, L1, ≥ 3D, where D is the outer edge diameter of the blind plate 30a, to ensure that the blind plate 30a / orifice plate 30b can be pushed out and in smoothly; similarly, the sum of the lengths of the second main rail segment 82 and the two second extended rail segments 84, L2, ≥ 3D, to ensure that the blind plate 30a / orifice plate 30b can be pushed out and in smoothly.

[0100] When the first gas outlet is coaxial with the second gas outlet, it is obvious that the first positive track section 81 is parallel with the second positive track section 82 .

[0101] The above-mentioned lifting device includes but is not limited to the use of a lifting hoist, which can be a manual hoist or an electric hoist.

[0102] The annular switching track 8 can be installed on the first cooling flue 1 through a bracket, or can be installed on a workshop foundation or equipment around the first cooling flue 1 .

[0103] Embodiment 5

[0104] This embodiment provides a water-cooled blind plate 30a, which can be used for the blind plate valve 3 in the above-mentioned embodiment 1 / embodiment 4.

[0105] like Figure 6-Figure 8 The water-cooled blind plate 30a includes a blind plate body 301, and a water cooling unit is arranged inside the blind plate body 301 to ensure that the blind plate body 301 can withstand a high temperature environment.

[0106] Optionally, the water cooling unit includes but is not limited to one or more cooling channels such as spiral cooling water channels and serpentine cooling water channels, and the cooling water inlet main pipe and the return water main pipe can be one or more. Wherein, when the water cooling unit adopts water cooling pipes, these water cooling pipes constitute a part of the blind plate body 301; the blind plate body 301 with a circular structure can be formed only by these water cooling pipes, or the blind plate body 301 can further include other components, such as fixing these water cooling pipes on the base plate.

[0107] The water inlet end 305 and the water return end 307 of the water cooling unit are located outside the outer periphery of the blind plate body 301 so as to be connected with the water inlet pipe and the water return pipe.

[0108] Further preferably, refractory material layers 302 are respectively cast on both sides of the blind plate body 301, so as to further improve the high temperature resistance and weather resistance of the water-cooled blind plate 30a, better protect the blind plate body 301, and greatly extend the service life of the water-cooled blind plate 30a; moreover, the maintenance cost of the refractory material layer 302 is low and very convenient, which can significantly reduce the maintenance cost of the water-cooled blind plate 30a. In one embodiment, a plurality of expansion joints are formed in the refractory material layer 302, and the expansion joints include but are not limited to the use of refractory aluminum silicate fiber felt or other refractory soft materials embedded in the refractory material to form a structure, so as to improve the cold and hot expansion performance of the refractory material layer 302, and can better meet the working condition characteristics of the non-continuous generation of converter gas.

[0109] Further preferably, anchoring claws are respectively provided on both sides of the blind plate body 301 , which can improve the bonding reliability between the refractory material layer 302 and the blind plate body 301 .

[0110] In one embodiment, a connecting flange (shown in the figure, not marked) is provided on the outer periphery of the blind plate body 301, and the connecting flange is used to connect with the valve seat flange.

[0111] Preferably, an annular sealing cavity 304 is formed on the outer periphery of the blind plate body 301 , and a sealing component is embedded in the sealing cavity 304 , and the sealing component includes but is not limited to a sealing rope.

[0112] In one embodiment, if Figure 6 and Figure 7, a purge unit 303 is provided at least on the air-facing surface of the blind plate body 301, which can be used to protect and purge the air-facing surface, including but not limited to nitrogen purge. Preferably, the purge unit 303 includes a purge main pipe 3031 and a plurality of short tube nozzles 3032 connected to the purge main pipe 3031, the purge main pipe 3031 is buried in the refractory material layer 302 on the air-facing side, and the nozzles of the short tube nozzles 3032 are flush with the outer surface of the refractory material layer 302. Among them, the purge main pipe 3031 is structured to form a plurality of annular distribution pipes, and a plurality of short tube nozzles 3032 are arranged on each annular distribution pipe, so that the short tube nozzles 3032 can be distributed to form a plurality of nozzle rings; the purge main pipe 3031 can also be distributed in a branch-like manner, and a plurality of short tube nozzles 3032 are respectively arranged on each branch.

[0113] The air inlet end 306 of the purge main pipe 3031 extends beyond the outer periphery of the blind plate body 301 to facilitate connection with a related air source.

[0114] More preferably, if Figure 6 The blowing direction of the short tube nozzle 3032 is inclined relative to the axis of the blind plate body 301. This method can improve the protective blowing effect and reduce the probability of clogging of the short tube nozzle 3032. It is further preferred to make the blowing direction of the short tube nozzle 3032 toward the axis of the blind plate body 301.

[0115] The above-mentioned purge main pipe 3031 is preferably fixedly connected to the blind plate body 301. It can be understood that the purge main pipe 3031, especially the setting of each short tube nozzle 3032, can play the role of an anchor, effectively improving the bonding reliability between the refractory material layer 302 and the blind plate body 301; at the same time, the refractory material layer 302 can reliably protect these purge units 303.

[0116] In one of the embodiments, the refractory material on the air-facing surface of the blind plate body 301 is a permeable refractory material. For example, the refractory material layer 302 on the air-facing surface includes a first refractory layer and a second refractory layer located outside the first refractory layer. The second refractory layer is a permeable refractory material, and the air permeability of the first refractory layer is lower than that of the second refractory layer. The above-mentioned purge main pipe 3031 can be arranged in the first refractory layer or in the second refractory layer. A plurality of air outlets can be set on the purge main pipe 3031 facing the second refractory layer for supplying air to the second refractory layer. Alternatively, a separate air supply pipe for supplying air to the second refractory layer can be set. Based on the above scheme, under the action of the gas passing through the second refractory layer, the dust on the gas-facing surface can be blown away or peeled off, thereby improving the protective purge effect; in addition, by supplying gas to the second refractory layer, it can also play a role in cooling the refractory layer 302, and better protect the water-cooled blind plate 30a. Cooling gas (inert gas, such as low-temperature nitrogen, should be used) can be supplied to the second refractory layer under specific operating conditions / abnormal operating conditions that may produce high-temperature / ultra-high-temperature converter gas (such as high-intensity oxygen blowing smelting in a converter, etc.).

[0117] Alternatively, if Fig. 9 On the basis of the above-mentioned water-cooled blind plate 30a, the blind plate body 301 and the refractory material layers 302 on both sides are hollowed out to form through holes according to a set diameter, so as to obtain a water-cooled orifice plate 30b, which can be used in the above-mentioned embodiment 4; wherein, preferably, the diameter of the through hole is smaller than the diameter of the blind plate body 301 and the refractory material layer 302.

[0118] Embodiment 6

[0119] The embodiment of the present invention provides a converter gas recovery method, which is implemented based on the converter gas recovery system provided in the above embodiment 1. The method specifically includes:

[0120] The two groups of valve control units are controlled to allow the converter gas to selectively enter the gas processing mechanism or the gas waste heat recovery mechanism for processing.

[0121] Among them, the choice of whether to let the converter gas enter the gas processing mechanism or the gas waste heat recovery mechanism can be based on the processing requirements, such as achieving wide-area waste heat recovery of the converter gas, or the actual working conditions, such as the gas waste heat recovery mechanism needs to be inspected and maintained.

[0122] Other specific processing measures have been described in the aforementioned embodiments and will not be repeated here.

[0123] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A converter gas recovery system, comprising a first cooling flue connected to a converter, characterized in that: The first cooling flue has a first gas outlet and a second gas outlet, the first gas outlet is connected to a gas processing mechanism, the second gas outlet is connected to a gas waste heat recovery mechanism, and valve control units are respectively provided at the first gas outlet and the second gas outlet.

2. The converter gas recovery system according to claim 1, characterized in that: Both groups of valve control units include valve seats, and the two share a group of gate plate assemblies, wherein the gate plate assembly includes a blind plate and an orifice plate, wherein the orifice plate is a gate plate with a through hole, and the blind plate is selectively inserted in one of the valve seats, and the orifice plate is inserted in the other valve seat; the system is also configured with a blind plate switching actuator for exchanging the positions of the blind plate and the orifice plate.

3. The converter gas recovery system according to claim 1, characterized in that: The coal gas waste heat recovery mechanism comprises a waste heat boiler, and a dust collector is connected to the flue gas inlet side of the waste heat boiler.

4. The converter gas recovery system according to claim 3, characterized in that: The waste heat boiler comprises a first return boiler, in which a longitudinal flushing heating surface is adopted.

5. The converter gas recovery system according to claim 4, characterized in that: The waste heat boiler further comprises a second return boiler, in which a plurality of stages of convection evaporators are arranged in sequence from bottom to top, wherein the heating surface of the convection evaporator is a transverse flushing heating surface.

6. The converter gas recovery system according to claim 3, characterized in that: The coal gas waste heat recovery mechanism further includes a second cooling flue, and the second cooling flue is respectively connected to the second coal gas outlet and the dust collector.

7. The converter gas recovery system according to claim 6, characterized in that: The second cooling flue is arranged obliquely, and its smoke inlet is located above its smoke outlet.

8. The converter gas recovery system according to claim 6, characterized in that: The second cooling flue or the dust collector is provided with an admixture adding mechanism for adding admixture to the coal gas, and the added admixture is a substance that can reduce the viscosity of dust in the coal gas.

9. A converter gas recovery method, characterized in that: Based on the implementation of the converter gas recovery system according to any one of claims 1 to 8, the method specifically comprises: The two groups of valve control units are controlled to allow the converter gas to selectively enter the gas processing mechanism or the gas waste heat recovery mechanism for processing.

10. The converter gas recovery method according to claim 9, characterized in that: When the converter gas enters the gas waste heat recovery mechanism for treatment, The converter gas first passes through the first cooling flue, and the outlet gas temperature of the first cooling flue is reduced to 800-900°C; The converter gas then passes through the second cooling flue, and the outlet gas temperature of the first cooling flue is reduced to 500-700°C; Subsequently, the converter gas is processed in turn by a dust collector and a waste heat boiler.

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