Waste heat boiler and converter gas waste heat recovery system

Abstract

The utility model relates to a waste heat boiler and a converter gas waste heat recovery system equipped with the waste heat boiler, the waste heat boiler comprises a first return stroke boiler, a second return stroke boiler and a settling chamber, the top of the first return stroke boiler is provided with a flue gas inlet, and the top of the second return stroke boiler is provided with a flue gas outlet. A bottom smoke outlet of the first return stroke boiler and a bottom smoke inlet of the second return stroke boiler are both communicated with an inner cavity of the settling chamber, and a longitudinal scouring heating surface is arranged in the first return stroke boiler. The waste heat boiler adopts a double-return-stroke structural design, so that the waste heat recovery effect can be ensured; a longitudinal scouring heating surface and a smoke longitudinal scouring heating surface are arranged in the first return stroke boiler, so that the smoke waste heat is recycled, the ash deposition degree can be effectively relieved, and the ash deposition condition is reduced; and the settling chamber can play a role in inertial dust removal, so that the probability of ash deposition and ash blockage of the waste heat boiler is further reduced.

Description

Technical Field

[0001] This utility model relates to a waste heat boiler and a converter gas waste heat recovery system equipped with the waste heat boiler. Background Technology

[0002] Waste heat boilers are crucial equipment in flue gas waste heat recovery processes. They utilize high-temperature waste gas or waste heat generated during industrial production to produce steam or hot water, offering high energy efficiency and are widely used in industries such as metallurgy, chemicals, building materials, and power. However, waste heat boilers are prone to ash accumulation, especially when processing flue gas with high dust content. Ash accumulation reduces heat exchange efficiency, increases energy consumption, and can even pose safety hazards. Currently, this problem is mainly addressed through regular ash removal. Converter gas has a high dust content, and the dust particles are highly adhesive. When using waste heat boilers for converter gas waste heat recovery, the ash accumulation problem becomes even more pronounced. Utility Model Content

[0003] This utility model relates to a waste heat boiler and a converter gas waste heat recovery system equipped with the waste heat boiler, which can at least solve some of the defects of the prior art.

[0004] This utility model relates to a waste heat boiler, including a first pass boiler, a second pass boiler, and a settling chamber. The top of the first pass boiler is provided with a flue gas inlet, and the top of the second pass boiler is provided with a flue gas outlet. The bottom flue gas outlet of the first pass boiler and the bottom flue gas inlet of the second pass boiler are both connected to the inner cavity of the settling chamber. The first pass boiler is provided with a longitudinally scouring heating surface.

[0005] As one embodiment, the longitudinal scouring heating surface includes multiple longitudinal evaporation tubes, the axis of which is parallel to the vertical direction, and bridging pipes are connected to both ends of the longitudinal evaporation tubes. The bridging pipes extend to the outside of the furnace shell of the first return boiler to connect to the corresponding medium pipes.

[0006] As one embodiment, the longitudinal evaporator tubes are distributed in multiple evaporator tube groups; in each evaporator tube group, the longitudinal evaporator tubes are distributed in the same vertical plane and are arranged sequentially from the inner wall of the furnace shell towards the furnace shell axis, and from the inner wall of the furnace shell towards the furnace shell axis, the top position of each longitudinal evaporator tube gradually rises and the bottom position of each longitudinal evaporator tube gradually decreases.

[0007] As one implementation method, the bridge pipe is arranged horizontally or inclined relative to the horizontal plane.

[0008] As one implementation method, at least a portion of the bridging pipes at the top of the longitudinal evaporator tubes are connected to the same distribution manifold, and at least a portion of the bridging pipes at the bottom of the longitudinal evaporator tubes are connected to the same distribution manifold.

[0009] As one implementation method, the second pass boiler has multiple stages of convection evaporators arranged sequentially from bottom to top, and the heating surface of the convection evaporator is a transverse scouring heating surface.

[0010] As one implementation method, in the second pass boiler, at least one economizer is arranged downstream of the last stage convective evaporator. When there are multiple economizers, they are arranged sequentially from bottom to top.

[0011] As one implementation method, both the first return boiler and the second return boiler are erected on the settling chamber.

[0012] As one implementation method, multiple soot blowers are arranged in both the first-pass boiler and the second-pass boiler.

[0013] This utility model also provides a converter gas waste heat recovery system, including a vaporization cooling flue for connection with the converter, and a waste heat boiler as described above, wherein the vaporization cooling flue is connected to the flue gas inlet of the first return boiler.

[0014] This utility model has at least the following beneficial effects:

[0015] The waste heat boiler adopts a double-pass structure design, which can ensure the waste heat recovery effect. The first pass boiler is equipped with a longitudinal flushing heating surface, and the flue gas longitudinally flushes the heating surface. While recovering the waste heat of the flue gas, it can effectively alleviate the degree of ash accumulation and reduce the occurrence of ash accumulation. The settling chamber can play a role in inertial dust removal, further reducing the probability of ash accumulation and ash blockage in the waste heat boiler. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of the converter gas waste heat recovery system provided in this embodiment of the utility model;

[0018] Figure 2 A schematic diagram of the waste heat boiler provided in an embodiment of this utility model;

[0019] Figure 3 A schematic diagram of the structure of the first-pass boiler provided in this embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the structure of a three-way flue provided in an embodiment of the present utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the annular switching track provided in an embodiment of the present utility model;

[0022] Figure 6 and Figure 7 A schematic diagram of the structure of the water-cooled blind plate provided in the embodiment of this utility model;

[0023] Figure 8 A schematic diagram of the structure of the water-cooled blind plate body;

[0024] Figure 9 This is a schematic diagram of the structure of the water-cooled perforated plate provided in an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] Example 1

[0027] like Figure 2 This utility model embodiment provides a waste heat boiler 6, including a first pass boiler 61, a second pass boiler 62 and a settling chamber 63. The top of the first pass boiler 61 is provided with a flue gas inlet, and the top of the second pass boiler 62 is provided with a flue gas outlet. The bottom flue gas outlet of the first pass boiler 61 and the bottom flue gas inlet of the second pass boiler 62 are both connected to the inner cavity of the settling chamber 63.

[0028] As can be seen, the aforementioned waste heat boiler 6 adopts a double-pass structure design. Flue gas is introduced from the flue gas inlet at the top of the first-pass boiler 61. After exchanging heat with the heating surfaces inside the first-pass boiler 61, the flue gas enters the settling chamber 63 from the first-pass boiler 61, and then enters the second-pass boiler 62. After exchanging heat with the heating surfaces inside the second-pass boiler 62, the flue gas is discharged from the flue gas outlet at the top of the second-pass boiler 62. The flue gas flows from top to bottom in the first-pass boiler 61 and from bottom to top in the second-pass boiler 62.

[0029] Among them, such as Figure 2 Preferably, the first return boiler 61 and the second return boiler 62 are both erected on the settling chamber 63. This not only facilitates the arrangement of the first return boiler 61 and the second return boiler 62 and greatly reduces the space occupied by the equipment, but also shortens the flue gas travel between the first return boiler 61 and the second return boiler 62, which is beneficial to the recovery of flue gas waste heat.

[0030] Preferably, in the first pass boiler 61, the heating surface 611 is longitudinally flushed, that is, the flue gas longitudinally flushes the heating surface 611. While recovering the waste heat of the flue gas, it can effectively alleviate the degree of ash accumulation and reduce the occurrence of ash accumulation.

[0031] In one embodiment, such as Figure 3 The longitudinal scouring heating surface 611 includes multiple longitudinal evaporation tubes 6111. The axis of the longitudinal evaporation tubes 6111 is parallel to the vertical direction. Both ends of the longitudinal evaporation tubes 6111 are respectively connected to bridging pipes 6112. The bridging pipes 6112 extend to the outside of the furnace shell to connect to the corresponding medium pipes.

[0032] Preferably, the medium flow direction in the longitudinal evaporator 6111 is from bottom to top, which is opposite to the flue gas flow direction in the first return boiler 61, thus improving the heat exchange effect; the bridge pipe 6112 at the bottom of the longitudinal evaporator 6111 is used to connect the inlet pipe, and the bridge pipe 6112 at the top of the longitudinal evaporator 6111 is used to connect the return pipe.

[0033] Preferably, at least a portion of the bridging pipe 6112 at the top of the longitudinal evaporator pipe 6111 is connected to the same distribution manifold 6113, and at least a portion of the bridging pipe 6112 at the bottom of the longitudinal evaporator pipe 6111 is connected to the same distribution manifold 6113. This facilitates centralized management of water inlet and outlet, and also reduces the number of on-site pipes and simplifies the layout.

[0034] Preferably, such as Figure 3 The longitudinal evaporator tubes 6111 are distributed to form multiple evaporator tube groups. Within each evaporator tube group, the longitudinal evaporator tubes 6111 are distributed in the same vertical plane and arranged sequentially from the inner wall of the furnace shell towards the furnace shell axis. Furthermore, from the inner wall of the furnace shell towards the furnace shell axis, the top position of each longitudinal evaporator tube 6111 gradually increases, and the bottom position of each longitudinal evaporator tube 6111 gradually decreases. This arrangement facilitates the arrangement of the longitudinal evaporator tubes 6111, allowing for the placement of as many longitudinal evaporator tubes 6111 as possible, thereby ensuring effective heat exchange with the flue gas. Understandably, the closer to the center of the furnace shell, the longer the heat exchange path of the longitudinal evaporator tubes 6111, which also better matches the flue gas flow field within the first pass boiler 61, correspondingly improving the heat exchange effect with the flue gas. Optionally, the same evaporator tube group shares a single inlet water distribution manifold 6113 and a return water distribution manifold 6113.

[0035] The longitudinal heat exchange tube can be a bare tube or a finned tube.

[0036] The bridging pipe 6112 can be arranged horizontally (with its axis parallel to the horizontal plane) or inclined (with its axis inclined relative to the horizontal plane). When the bridging pipe 6112 is arranged inclined, for example, the top end of the longitudinal evaporator pipe 6111 extends obliquely upward to form the top bridging pipe 6112 and the bottom end of the longitudinal evaporator pipe 6111 extends obliquely downward to form the bottom bridging pipe 6112, the flushing effect of the flue gas helps to alleviate the accumulation of ash on the bridging pipe 6112.

[0037] The aforementioned first-pass boiler 61 preferably adopts a membrane water-cooled wall. With the combination of the longitudinally scouring heating surface 611 and the water-cooled wall, the recovery effect and efficiency of the flue gas waste heat can be guaranteed.

[0038] In one embodiment, such as Figure 2 The second-pass boiler 62 has multiple stages of convective evaporators 621 arranged sequentially from bottom to top. Preferably, the convective evaporators 621 adopt a transverse scouring heating surface, that is, the flue gas scouring the heating surface of the convective evaporators 621 transversely. Specifically, the convective evaporator 621 includes multiple transverse evaporation tubes, and the axis of the transverse evaporation tubes is preferably parallel to the horizontal plane.

[0039] When the aforementioned waste heat boiler 6 is used for gas treatment, after the preceding multi-stage cooling, the gas temperature entering the second pass boiler 62 is relatively low. The ash accumulated in the second pass boiler 62 is mainly loose ash, which is relatively easy to remove. Furthermore, using horizontal evaporator tubes can improve the heat exchange effect and efficiency with the gas. Even if ash accumulates, ash blockage is less likely to occur. Preferably, the gas temperature at the outlet side of the first pass boiler 61 is below the temperature of sticky ash (defined as the temperature of gas that easily forms sticky ash), which can ensure the normal operation of the second pass boiler 62. Specifically, the gas temperature at the outlet side of the first pass boiler 61 is reduced to 400-600℃.

[0040] The horizontal evaporator tube can be either a bare tube or a finned tube.

[0041] Among them, multiple horizontal evaporation tubes can be arranged on the cross-section of the convection evaporator 621; the vertical arrangement of the horizontal evaporation tubes can be in a straight line, staggered, or a combination of the two arrangements.

[0042] The convection evaporators 621 at each stage can be connected in series (the water inlet runs from the uppermost convection evaporator 621 to the lower convection evaporators 621 in sequence), or they can be connected in parallel (the water inlet and outlet of each convection evaporator 621 are independent of each other), or some convection evaporators 621 can be connected in series.

[0043] More preferably, such as Figure 2In the second pass boiler 62, at least one economizer 622 is arranged downstream of the final stage convective evaporator 621. When there are multiple economizers 622, they are arranged sequentially from bottom to top.

[0044] Preferably, the flue gas laterally washes over the heating surface of the economizer 622.

[0045] Optionally, the economizer 622 includes multiple serpentine evaporator tubes, which extend in a serpentine pattern across the cross-section of the economizer 622. The vertical arrangement of each serpentine evaporator tube can be in a straight line, staggered, or a combination of both.

[0046] Among them, the serpentine evaporator tube can be a bare tube or a finned tube.

[0047] Preferably, multiple soot blowers are arranged in both the first pass boiler 61 and the second pass boiler 62 to periodically clean the heating surfaces, ensuring that the heating surfaces are clean and unobstructed. The soot cleaning method can be one or a combination of nitrogen shock wave, acetylene shock wave, high-efficiency sonic wave, steam soot blowing, etc. Furthermore, detectors are arranged in both the first pass boiler 61 and the second pass boiler 62. The detectors can be carbon monoxide concentration detectors and / or oxygen concentration detectors. Preferably, the detectors are interlocked with the soot blowers to achieve automatic control of soot blowing.

[0048] Optionally, both the first pass boiler 61 and the second pass boiler 62 are provided with maintenance manholes.

[0049] The first pass boiler 61 and the settling chamber 63, and the second pass boiler 62 and the settling chamber 63, can be fixed by welding, flange, or integral molding. The settling chamber 63 serves as an inertial dust collector, further reducing the likelihood of ash accumulation and blockage in the waste heat boiler 6. Additionally, dust falling from the first pass boiler 61 and the second pass boiler 62 will enter the settling chamber 63, thus facilitating dust recovery.

[0050] Example 2

[0051] like Figure 1 This utility model provides a converter gas waste heat recovery system, including a vaporization cooling flue for connection to the converter, and a waste heat boiler 6 provided in the first embodiment above. The vaporization cooling flue is connected to the flue gas inlet of the first return boiler 61.

[0052] Preferably, such as Figure 1 The vaporization cooling flue includes a first cooling flue 1, which is used to connect to the converter.

[0053] Furthermore, such as Figure 1The vaporization cooling flue also includes a second cooling flue 4, the flue gas inlet of which is connected to the first cooling flue 1. The converter gas can be cooled through the first cooling flue 1 and the second cooling flue 4, achieving effective temperature reduction of the converter gas and significantly reducing the probability of sticky ash accumulation in the waste heat boiler 6; at the same time, the setting of the second cooling flue 4 also facilitates the layout of equipment such as the waste heat boiler 6.

[0054] In one embodiment, such as Figure 1 A dust collector 5 is connected to the flue gas inlet side of the waste heat boiler 6. This dust collector 5 pre-depreciates the converter gas, significantly reducing the dust content of the gas entering the waste heat boiler 6, alleviating the ash load of the boiler, and effectively removing any ignition sources carried in the gas, further improving system safety. The dust collector 5 includes, but is not limited to, inertial dust collectors, but preferably cyclone dust collectors, which have good dust removal effect and efficiency. The aforementioned vaporization cooling flue is connected to the dust collector 5. When the vaporization cooling flue includes a first cooling flue 1 and a second cooling flue 4, the second cooling flue 4 is connected to the dust collector 5.

[0055] The dust collector 5 can be equipped with cooling measures, such as water-cooled walls. This can improve the service life of the dust collector 5 and cool the converter gas, reducing the ash stickiness in the converter gas and thus reducing the probability of sticky ash accumulation in the waste heat boiler 6.

[0056] Preferably, such as Figure 1 The second cooling flue 4 is arranged at an angle, and its flue gas inlet is located above its flue gas outlet. The angled 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 gas flow direction is the same as the ash particle flow direction, and the gas flow velocity in the second cooling flue 4 is relatively high. Therefore, the gas can carry the ash particles and flow by itself, thereby avoiding ash accumulation in the second cooling flue 4.

[0057] Preferably, the second cooling flue 4 has an inclination angle of 30° to 80° relative to the horizontal plane.

[0058] More preferably, such as Figure 1The 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 end 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 that 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 that of the second inclined flue section 42. Based on this design, the large inclination angle of the first inclined flue section 41 is beneficial for driving away dust through the gas; the two-section flue section design with different inclination angles increases the flue gas turbulence to a certain extent, thereby improving the heat exchange effect between the gas and the flue wall. Moreover, the two-section flue design can reduce the phenomenon of thermal stress concentration 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 arrangement 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°.

[0059] In the above system, the waste heat recovery of converter gas over a wide area can be achieved through the first cooling flue 1 + the second cooling flue 4 + (water-cooled dust collector 5) + waste heat boiler 6, which greatly avoids the waste of sensible heat of converter gas.

[0060] 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 around 850°C.

[0061] Preferably, the outlet gas temperature of the second cooling flue 4 is reduced to 500-700°C.

[0062] Preferably, a ash removal device is installed in the second cooling flue 4, waste heat boiler 6 and other parts to regularly remove ash from the heating surface to ensure that the heating surface is clean and unobstructed; the ash removal method can be one or a combination of nitrogen shock wave, acetylene shock wave, high-efficiency sonic wave, steam blowing and other ash removal methods.

[0063] In one embodiment, an additive addition mechanism is provided on the second cooling flue 4 or the dust collector 5 to add additives to the coal gas. The added additives are substances that can reduce the stickiness of dust in the coal gas, including but not limited to kaolin or quartz sand. Kaolin and quartz sand are high-melting-point substances and are solid particles at the waste heat recovery temperature. When mixed with converter ash, they can increase the overall ash melting point, thereby reducing ash stickiness. In this way, the sticky ash accumulation in the subsequent waste heat boiler 6 can be greatly alleviated, improving the reliability of system operation. Preferably, the additive addition mechanism is provided on the second cooling flue 4, which is conducive to the full reaction of the additive with the coal gas, especially to the removal of the reacted ash particles in the dust collector 5, reducing the ash load of the waste heat boiler 6. When the above-mentioned additives are added by powder injection, a better reaction effect and efficiency can be achieved. Therefore, the above-mentioned additive addition mechanism may include a powder injection gun provided on the second cooling flue 4 / dust collector 5. The powder injection gun is equipped with a powder hopper and a pressure medium supply mechanism. The pressure medium is preferably an inert gas such as nitrogen.

[0064] In one embodiment, such as Figure 1 The aforementioned converter gas waste heat recovery system is also equipped with a backup gas treatment mechanism. When the waste heat recovery mechanism (including waste heat boiler 6, dust collector 5, etc.) is shut down, it can be switched to the backup gas treatment mechanism for treatment. Therefore, it is convenient to inspect and maintain the waste heat recovery mechanism and ensure the stability of converter steelmaking production.

[0065] Preferably, the first cooling flue 1 has a first gas outlet and a second gas outlet. The first gas outlet is connected to the aforementioned backup gas treatment mechanism, and the second gas outlet is connected to the second cooling flue 4. Valve control units 3 are respectively provided at the first gas outlet and the second gas outlet.

[0066] The aforementioned backup gas treatment unit may employ conventional gas treatment processes, including but not limited to the use of evaporative coolers 7.

[0067] In one embodiment, such as Figure 1 The end of the first cooling flue 1 adopts a three-way flue 2, which has a gas inlet and two gas outlets, namely the first gas outlet and the second gas outlet.

[0068] Optionally, the valve control unit 3 mentioned above adopts a slide gate valve 3, including but not limited to a blind valve 3.

[0069] Preferably, explosion relief valves are installed at locations such as the three-way flue 2 and the waste heat boiler 6, so that in the event of a gas explosion, the explosion can be relieved in a timely and effective manner, ensuring the safety of personnel and equipment.

[0070] Example 3

[0071] This embodiment provides a three-way flue 2, which can be used in the above embodiment two.

[0072] like Figure 4 The three-way flue 2 includes a flue gas inlet section 21 and two flue gas outlet sections 22. The flue gas inlet section 21 and the two flue gas outlet sections 22 are both in the form of vaporization cooling flue, that is, the flue gas inlet section 21 and the flue gas outlet section 22 are formed by multiple vaporization cooling pipes surrounding each other to form the corresponding flue.

[0073] In one embodiment, a portion of the vaporization cooling pipes of the flue gas inlet section 21 is coupled to one of the flue gas outlet sections 22 to form a first heating surface, and the remaining vaporization cooling pipes of the flue gas inlet section 21 are coupled to the other flue gas outlet section 22 to form a second heating surface; for example, the left half of the flue gas inlet section 21 is coupled to the flue gas outlet section 22 on its left to form the first heating surface, and the right half of the flue gas inlet section 21 is coupled to the flue gas outlet section 22 on its right to form the second heating surface. Based on the above design, the number of steam and water pipes can be reduced, which is beneficial for on-site implementation.

[0074] For ease of description, the vaporization cooling pipe of flue gas inlet section 21 is defined as the first cooling pipe 211, and the vaporization cooling pipe of flue gas outlet section 22 is defined as the second cooling pipe 221.

[0075] For coupling between vaporization cooling pipes, the vaporization cooling pipes are connected to form a water channel. 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 sequence for heat exchange, and then exits from the second vaporization cooling pipe to form cooling return water.

[0076] More preferably, each first cooling pipe 211 is coupled with multiple second cooling pipes 221, including but not limited to one first cooling pipe 211 coupled with two second cooling pipes 221. For the structure of one first cooling pipe 211 coupled with two second cooling pipes 221, preferably, as shown... Figure 4 A Y-shaped cooling pipe 23 is used for coupling. The two ends of the Y-shaped cooling pipe 23 are connected to two second cooling pipes 221, and the other end is connected to the first cooling pipe 211. Based on this structure, reliable coupling between the flue gas inlet section 21 and the flue gas outlet section 22 can be achieved, a reasonable heat-receiving surface can be designed, and the vaporization cooling effect and heat uniformity at all points of the three-way flue 2 can be guaranteed.

[0077] Among them, flat steel partitions or the like can be used to seal the adjacent Y-shaped trouser tubes 23.

[0078] The first heating surface is equipped with one or more inlet water headers and one or more return water headers. Preferably, the number of inlet water headers and return water headers are the same and they are configured in a one-to-one correspondence. For example, in a structure where the left half of the flue gas inlet section 21 is coupled with the flue gas outlet section 22 on its left to form the first heating surface, the first cooling pipes 211 in the upper half can share one inlet water header and the second cooling pipes 221 can share one return water header, and the first cooling pipes 211 in the lower half can share one inlet water header and the second cooling pipes 221 can share one return water header. Furthermore, the two inlet water headers are connected to the same inlet water pipe, and the two return water headers are connected to the same return water pipe. The second heating surface can adopt the same inlet and return water configuration.

[0079] In another embodiment, the heating surface can be configured as follows: a portion of the vaporization cooling pipe of the flue gas inlet section 21 is coupled with the lower half of one of the flue gas outlet sections 22 to form heating surface #1; the remaining vaporization cooling pipe of the flue gas inlet section 21 is coupled with the lower half of the other flue gas outlet section 22 to form heating surface #2; and the upper halves of the two flue gas outlet sections 22 are coupled to form heating surface #3.

[0080] Example 4

[0081] This embodiment further optimizes the above embodiment two. Specifically, the two sets of valve control units are further optimized as follows:

[0082] Both sets of valve control units include valve seats and share a gate assembly. The gate assembly includes a blind plate 30a and an orifice plate 30b, where the orifice plate 30b is a gate with a through hole. The blind plate 30a is selectively inserted into one valve seat, and the orifice plate 30b is inserted into the other. When the blind plate 30a is inserted into one valve seat, that valve control unit is in a closed state, while the other valve control unit is in an open state due to the orifice plate 30b at its valve seat. Based on this design, converter gas can only enter one of the backup gas processing mechanism and the waste heat recovery mechanism, and will not enter both mechanisms simultaneously, ensuring system operational reliability and avoiding malfunctions. The use of the blind plate 30a and the orifice plate 30b for switching ensures the sealing of the first and second gas outlets.

[0083] When two mechanisms need to switch operation, for example, switching from the operation of the waste heat recovery mechanism to the operation of the standby gas treatment mechanism, the insertion position of the blind plate 30a needs to be switched, that is, the blind plate 30a is switched from the valve seat that is currently in the closed state to the valve seat that is currently in the open state. Accordingly, a blind plate switching actuator is provided.

[0084] like Figure 5The blind plate switching actuator includes a ring switching track 8 and two sets of lifting devices movably mounted on the ring switching track 8. The ring switching track 8 includes a first main track section 81 located directly above the first gas outlet, a second main track section 82 located directly above the second gas outlet, and a transfer track section connecting the first main track section 81 and the second main track section 82. The guiding direction of the first main track section 81 is perpendicular to the axial direction of the first gas outlet, and the guiding direction of the second main track section 82 is perpendicular to the axial direction of the second gas outlet.

[0085] The aforementioned lifting device is used to lift the gate 30 at one of the gas outlets (first gas outlet / second gas outlet), and then move it on the circular switching track 8 to the other gas outlet for installation. The circular switching track 8 can ensure the smooth relative movement of the blind plate 30a and the orifice plate 30b, and the blind plate 30a and the orifice plate 30b can move synchronously to the target position for installation, thereby improving maintenance efficiency and saving maintenance time.

[0086] Preferably, such as 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, among which,

[0087] Two first extension track sections 83 are connected to both ends of the first main track section 81, and the guiding direction of the two first extension track sections 83 is parallel to the guiding direction of the first main track section 81. This improves the smoothness and reliability of the gate replacement at the first gas outlet.

[0088] Two second extension track sections 84 are connected to both ends of the second main track section 82, and the guiding direction of the two second extension track sections 84 is parallel to the guiding direction of the second main track section 82. This improves the smoothness and reliability of the gate replacement at the second gas outlet.

[0089] The first extension track segment 83 and the second extension track segment 84 on the same side are connected by a relay track segment 85.

[0090] Preferably, the sum of the lengths of the first main track section 81 and the two first extended track sections 83, L1, is greater than or equal to 3D, where D is the outer diameter of the blind plate 30a, to ensure that the blind plate 30a / orifice plate 30b can be smoothly pushed out and pushed in; similarly, the sum of the lengths of the second main track section 82 and the two second extended track sections 84, L2, is greater than or equal to 3D, to ensure that the blind plate 30a / orifice plate 30b can be smoothly pushed out and pushed in.

[0091] When the first gas outlet and the second gas outlet are coaxial, it is obvious that the first main track section 81 and the second main track section 82 are parallel.

[0092] The aforementioned lifting devices include, but are not limited to, lifting hoists, which can be manual or electric hoists.

[0093] The aforementioned annular switching track 8 can be installed on the first cooling flue 1 via a bracket, or it can be installed on the workshop foundation or equipment around the first cooling flue 1.

[0094] Example 5

[0095] This embodiment provides a water-cooled blind plate 30a, which can be used in the blind plate valve 3 in the above embodiments two / four.

[0096] like Figures 6-8 The water-cooled blind plate 30a includes a blind plate body 301, and a water-cooling unit is provided inside the blind plate body 301 to ensure that the blind plate body 301 can withstand high temperature environment.

[0097] 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 manifold and return manifold can be one or more. When the water-cooling unit uses water-cooling pipes, these water-cooling pipes form part of the blind plate body 301; the blind plate body 301 can be constructed solely from these water-cooling pipes to form a circular structure, or the blind plate body 301 can further include other components, such as fixing these water-cooling pipes to the substrate.

[0098] The water inlet 305 and the return water end 307 of the water-cooling unit are located outside the outer periphery of the blind plate body 301, so as to facilitate connection with the water inlet pipe and the return water pipe.

[0099] More preferably, refractory material layers 302 are cast on both sides of the blind plate body 301, further improving the high-temperature resistance and weather resistance of the water-cooled blind plate 30a, better protecting the blind plate body 301, and greatly extending 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, multiple expansion joints are formed in the refractory material layer 302. The expansion joints include, but are not limited to, structures formed by embedding refractory aluminosilicate fiber felt or other refractory soft materials in the refractory material. This can improve the thermal expansion performance of the refractory material layer 302, which can better meet the operating conditions of discontinuous converter gas production.

[0100] More preferably, anchoring claws are provided on both sides of the blind flange body 301, which can improve the reliability of the connection between the refractory material layer 302 and the blind flange body 301.

[0101] In one embodiment, the outer periphery of the blind flange body 301 is provided with a connecting flange for connection to the valve seat flange.

[0102] 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. The sealing component includes, but is not limited to, a sealing rope.

[0103] In one embodiment, such as Figure 6 and Figure 7 A purging unit 303 is provided at least on the air-facing surface of the blind flange body 301 to protect the air-facing surface through purging, including but not limited to nitrogen purging. Preferably, the purging unit 303 includes a purging main pipe 3031 and a plurality of short pipe nozzles 3032 connected to the purging main pipe 3031. The purging main pipe 3031 is embedded in the refractory material layer 302 on the air-facing side, and the nozzles of the short pipe nozzles 3032 are flush with the outer surface of the refractory material layer 302. The purging main pipe 3031 is constructed as a plurality of annular distribution pipes, and a plurality of short pipe nozzles 3032 are provided on each annular distribution pipe, so that the short pipe nozzles 3032 are distributed to form a plurality of nozzle rings; the purging main pipe 3031 may also be branched, with a plurality of short pipe nozzles 3032 provided on each branch.

[0104] The air inlet 306 of the purge main pipe 3031 extends beyond the outer periphery of the blind plate body 301 to facilitate connection with the relevant air source.

[0105] More preferably, such as Figure 6 The blowing direction of the short pipe 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 chance of the short pipe nozzle 3032 getting clogged. More preferably, the blowing direction of the short pipe nozzle 3032 is oriented toward the axis of the blind plate body 301.

[0106] The aforementioned purge main pipe 3031 is preferably fixedly connected to the blind plate body 301. Understandably, the purge main pipe 3031, especially the short pipe nozzles 3032, can act as anchors, effectively improving the reliability of the connection 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.

[0107] In one embodiment, the refractory material on the air-facing surface of the blind flange body 301 is a breathable 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 made of a breathable refractory material, and the air permeability of the first refractory layer is lower than that of the second refractory layer. The aforementioned purge pipe 3031 can be arranged in the first refractory layer or in the second refractory layer. Multiple air outlets can be provided on the purge pipe 3031 facing the second refractory layer for supplying air to the second refractory layer; or, a separate air supply pipe can be provided to supply air to the second refractory layer. Based on the above scheme, under the action of the gas permeating the second refractory layer, the dust on the air-facing surface can be blown away or peeled off, thereby improving the protective purging effect. In addition, by supplying gas to the second refractory layer, it can also cool the refractory material layer 302, better protect the water-cooled blind plate 30a, and supply cooling gas (inert gas, such as low-temperature nitrogen) to the second refractory layer under specific / abnormal operating conditions that may generate high-temperature / ultra-high-temperature converter gas.

[0108] Optionally, such as Figure 9 Based on 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, and a water-cooled perforated plate 30b can be obtained. The water-cooled perforated plate 30b can be used in the above-mentioned embodiment four; 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.

[0109] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A waste heat boiler, characterized in that, It includes a first pass boiler, a second pass boiler, and a settling chamber. The first pass boiler has a flue gas inlet at the top, and the second pass boiler has a flue gas outlet at the top. The flue gas outlet at the bottom of the first pass boiler and the flue gas inlet at the bottom of the second pass boiler are both connected to the inner cavity of the settling chamber. The first pass boiler is provided with a longitudinally scouring heating surface.

2. The waste heat boiler as described in claim 1, characterized in that: The longitudinal scouring heating surface includes multiple longitudinal evaporation tubes, the axis of which is parallel to the vertical direction. Each end of the longitudinal evaporation tube is connected to a bridging pipe, which extends to the outside of the furnace shell of the first pass boiler to connect to the corresponding medium pipe.

3. The waste heat boiler as described in claim 2, characterized in that: The longitudinal evaporator tubes are distributed to form multiple evaporator tube groups; in each evaporator tube group, the longitudinal evaporator tubes are distributed in the same vertical plane and are arranged sequentially from the inner wall of the furnace shell towards the furnace shell axis. Furthermore, from the inner wall of the furnace shell towards the furnace shell axis, the top position of each longitudinal evaporator tube gradually increases and the bottom position of each longitudinal evaporator tube gradually decreases.

4. The waste heat boiler as described in claim 2, characterized in that: The bridge pipes are arranged horizontally or inclined relative to the horizontal plane.

5. The waste heat boiler as described in claim 2, characterized in that: At least a portion of the bridging pipes at the top of the longitudinal evaporator tubes are connected to the same distribution manifold, and at least a portion of the bridging pipes at the bottom of the longitudinal evaporator tubes are connected to the same distribution manifold.

6. The waste heat boiler as described in claim 1, characterized in that: The second pass boiler has multiple stages of convection evaporators arranged sequentially from bottom to top, and the heating surface of the convection evaporator is a transverse scouring heating surface.

7. The waste heat boiler as described in claim 6, characterized in that: In the second pass boiler, at least one economizer is arranged downstream of the last stage convective evaporator. If there are multiple economizers, they are arranged sequentially from bottom to top.

8. The waste heat boiler as described in claim 1, characterized in that: Both the first pass boiler and the second pass boiler are erected on the settling chamber.

9. The waste heat boiler as described in claim 1, characterized in that: Multiple soot blowers are installed in both the first-pass and second-pass boilers.

10. A converter gas waste heat recovery system, comprising a vaporization cooling flue for connection to the converter, characterized in that: It also includes a waste heat boiler as described in any one of claims 1 to 9, wherein the vaporization cooling flue is connected to the flue gas inlet of the first return boiler.

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