A high-proportion circulating flue gas distribution device with stepped air distribution, graded oxygen supplementation

Abstract

The present invention belongs to the technical field of sintering flue gas circulation, and particularly relates to a high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation, comprising: a circulating flue gas distribution main pipe, the circulating flue gas distribution main pipe comprising a number of step sections connected in sequence, the pipe diameters of the several step sections decreasing in sequence along the direction of flue gas movement; the oxygen content requirements of the several step sections arranged along the direction of flue gas movement increasing in sequence, and the air volume requirements decreasing in sequence; a circulating flue gas distribution branch pipe, connected and arranged on one side of the corresponding step section; a flue gas sealing hood, connected to the air outlet ends of several circulating flue gas distribution branch pipes; an oxygen supplementation device, arranged in the circulating flue gas distribution branch pipe where the oxygen content needs to be increased; and an oxygen supply device, connected to the air inlet end of the oxygen supplementation device. This device realizes graded oxygen supplementation in the process of high-proportion flue gas circulation, overcomes the limitation of the circulating oxygen content of the flue gas on the circulation rate and the adverse effect on production, and has a simple and reliable structure.

Description

Technical Field

[0001] The invention belongs to the technical field of sintering fume circulation, and in particular relates to a stepped air distribution, graded oxygen supplementation and high-proportion circulating fume distribution device. Background Art

[0002] The sintering flue gas circulation technology recycles part of the sintering hot waste gas, reduces the amount of exhaust gas, recovers and utilizes part of the waste heat of the waste gas, reduces the processing load of the flue gas purification facilities, and reduces the amount of sintering solid fuel used.

[0003] As the mainstream technology for green upgrading and transformation of sintering machines, sintering flue gas circulation technology has been applied in some areas, and the general flue gas circulation rate is between 15% and 20%. By increasing the flue gas circulation rate, the sintering flue gas emissions can be greatly reduced, the high-temperature decomposition of flue gas CO and dioxins can be enhanced, and the catalytic reduction of NOX can be promoted. However, when the circulation rate is increased to more than 30%, the oxygen content in the sintering process will be reduced. In addition, the large amount of high-temperature exhaust gas returns to the surface of the sintering material layer, and the uneven distribution can easily cause flue gas overflow, causing safety hazards. Therefore, how to achieve uniform distribution of large-volume flue gas and break through the problem of low-oxygen sintering is the key to achieving a high proportion of flue gas circulation. Summary of the invention

[0004] The object of the present invention is to provide a high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation to solve the above-mentioned problems.

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

[0006] A high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation, comprising:

[0007] A circulating smoke distribution main pipe, the circulating smoke distribution main pipe comprising a plurality of stepped sections connected in sequence, wherein the pipe diameters of the plurality of stepped sections decrease in sequence along the direction of smoke movement;

[0008] The oxygen content requirements of the plurality of step sections arranged along the direction of flue gas movement increase successively, and the air volume requirements decrease successively;

[0009] A circulating flue gas distribution branch pipe is connected and arranged on one side of the corresponding step section;

[0010] A smoke sealing cover is connected to the gas outlet ends of the plurality of circulating smoke distribution branch pipes;

[0011] An oxygen supplement device is arranged in the circulating flue gas distribution branch pipe where the oxygen content needs to be increased;

[0012] The oxygen supply device is connected to the air inlet end of the oxygen supplement device.

[0013] Preferably, the oxygen supplementation device is provided in the circulating flue gas distribution branch pipe within the end 1 / 3 length range of the circulating flue gas distribution main pipe along the flue gas movement direction.

[0014] Preferably, the oxygen supplementation device includes an oxygen supplementation gas branch pipe, which is located below the corresponding circulating smoke gas distribution branch pipe, and the oxygen supplementation gas branch pipe is inserted obliquely upward into the middle part of the corresponding circulating smoke gas distribution branch pipe. The air outlet end of the oxygen supplementation gas branch pipe is connected with the corresponding circulating smoke gas distribution branch pipe, and the air outlet end of the oxygen supplementation gas branch pipe is arranged close to the smoke sealing hood, and the air inlet end of the oxygen supplementation gas branch pipe is arranged close to the circulating smoke gas distribution main pipe, and the air inlet ends of several of the oxygen supplementation gas branch pipes are connected with the air outlet end of the oxygen supply device.

[0015] Preferably, a conical guide device is provided in the middle of the inner side of the circulating flue gas distribution branch pipe, the tip of the conical guide device is arranged toward the flue gas sealing cover, and the outlet end of the oxygen supplementary gas branch pipe is arranged toward the side wall of the conical guide device.

[0016] Preferably, the oxygen supply device comprises an oxygen-supplementing gas main pipe, a side wall of which is connected to the air inlet ends of a plurality of the oxygen-supplementing gas branch pipes, and a regulating part for regulating the oxygen flow is provided between the oxygen-supplementing gas main pipe and the oxygen-supplementing gas branch pipes.

[0017] Preferably, the regulating part comprises an oxygen-supplementing gas inlet regulating valve, one end of which is connected to the side wall of the oxygen-supplementing gas main pipe, and the other end of which is connected to the air inlet end of the oxygen-supplementing gas branch pipe.

[0018] Preferably, the oxygen supplement gas inlet regulating valve is one of a regulating single plate valve, a butterfly valve or a plug valve.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] The present invention adopts a stepped arrangement of a variable diameter structure according to the different air volume requirements and oxygen demand requirements of various parts of the circulating flue gas distribution main pipe, thereby realizing a stepped distribution of the circulating flue gas air volume, realizing the on-demand distribution of the circulating flue gas on the sintering material surface, and effectively increasing the circulating flue gas proportion to more than %. An oxygen supply device is added to the circulating flue gas distribution branch pipe that needs oxygen supply, so as to supply oxygen to the corresponding circulating flue gas distribution branch pipe according to the actual oxygen content demand, thereby realizing graded oxygen supply in the high-proportion flue gas circulation process, overcoming the limitation of the flue gas circulation oxygen content on the circulation rate and the adverse effect on production, and having a simple and reliable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0022] Figure 1 It is a schematic diagram of the structure of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the oxygen supplementation device of the present invention;

[0024] Among them, 1. circulating flue gas distribution main pipe; 2. circulating flue gas distribution branch pipe; 3. flue gas sealing hood; 4. oxygen-supplementing gas main pipe; 5. oxygen-supplementing gas branch pipe; 6. conical guide device; 7. oxygen-supplementing gas inlet regulating valve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Reference Figure 1 to Figure 2 The present invention discloses a high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation, comprising:

[0028] The circulating flue gas distribution main pipe 1 comprises a plurality of stepped sections connected in sequence, and the pipe diameters of the plurality of stepped sections decrease in sequence along the direction of flue gas movement;

[0029] The oxygen content requirements of the several steps arranged along the direction of flue gas movement increase successively, and the air volume requirements decrease successively;

[0030] The circulating flue gas distribution branch pipe 2 is connected and arranged on one side of the corresponding step section;

[0031] The smoke sealing cover 3 is connected to the gas outlet ends of a plurality of circulating smoke distribution branch pipes 2;

[0032] An oxygen supply device is arranged in the circulating flue gas distribution branch pipe 2 where the oxygen content needs to be increased;

[0033] The oxygen supply device is connected to the air inlet end of the oxygen supplement device.

[0034] The circulating flue gas distribution main pipe 1 is arranged parallel to the length direction of the sintering machine and is located above one side of the sintering machine. The flue gas sealing cover 3 covers the top of the sintering machine.

[0035] The present invention adopts a stepped arrangement of a variable diameter structure according to the different air volume requirements and oxygen demand requirements of various parts of the circulating flue gas distribution main pipe 1, so as to realize the stepped distribution of the circulating flue gas air volume, realize the on-demand distribution of the circulating flue gas on the sintering material surface, and effectively increase the circulating flue gas ratio to more than 35%. An oxygen supply device is added to the circulating flue gas distribution branch pipe 2 that needs oxygen supply, so as to supply oxygen to the corresponding circulating flue gas distribution branch pipe 2 according to the actual oxygen content demand, so as to realize graded oxygen supply in the high-ratio flue gas circulation process, overcome the limitation of the flue gas circulation oxygen content on the circulation rate and the adverse effect on production, and the structure is simple and reliable.

[0036] To further optimize the solution, an oxygen supply device is provided in the circulating flue gas distribution branch pipe 2 within the end 1 / 3 length range of the circulating flue gas distribution main pipe 1 along the direction of flue gas movement.

[0037] A further optimization scheme is provided, the oxygen supply device comprises an oxygen supply gas branch pipe 5, the oxygen supply gas branch pipe 5 is located below the corresponding circulating flue gas distribution branch pipe 2, the oxygen supply gas branch pipe 5 is obliquely inserted upward into the middle part of the corresponding circulating flue gas distribution branch pipe 2, the gas outlet end of the oxygen supply gas branch pipe 5 is connected with the corresponding circulating flue gas distribution branch pipe 2, the gas outlet end of the oxygen supply gas branch pipe 5 is arranged close to the flue gas sealing cover 3, the gas inlet end of the oxygen supply gas branch pipe 5 is arranged close to the circulating flue gas distribution main pipe 1, and the gas inlet ends of several oxygen supply gas branch pipes 5 are connected with the gas outlet end of the oxygen supply device.

[0038] To further optimize the solution, a conical guide device 6 is provided in the middle of the inner side of the circulating flue gas distribution branch pipe 2 , the tip of the conical guide device 6 is arranged toward the flue gas sealing cover 3 , and the outlet end of the oxygen supplementary gas branch pipe 5 is arranged toward the side wall of the conical guide device 6 .

[0039] According to a further optimization scheme, the oxygen supply device includes an oxygen-supplementing gas main pipe 4, a side wall of which is connected to the air inlet ends of a plurality of oxygen-supplementing gas branch pipes 5, and a regulating part for regulating the oxygen flow is provided between the oxygen-supplementing gas main pipe 4 and the oxygen-supplementing gas branch pipes 5.

[0040] To further optimize the solution, the regulating part includes an oxygen-supplementing gas inlet regulating valve 7, one end of the oxygen-supplementing gas inlet regulating valve 7 is connected to the side wall of the oxygen-supplementing gas main pipe 4, and the other end of the oxygen-supplementing gas inlet regulating valve 7 is connected to the air inlet end of the oxygen-supplementing gas branch pipe 5.

[0041] According to a further optimization scheme, the oxygen supplement gas inlet regulating valve 7 is a regulating single-plate valve, a butterfly valve or a plug-in valve.

[0042] In order to solve the problem of low oxygen and large air volume in high-ratio circulation, we systematically studied the air volume distribution and oxygen demand on the surface of the sintering material layer. We found that along the length of the sintering machine, due to different sintering stages, there are obvious differences in the permeability of the material layer and the demand for oxygen content is also different.

[0043] The first 1 / 3 of the length of the sintering machine is the initial stage of sintering. The sintering reaction mainly occurs on the surface of the material layer. The combustion is fragile, the oxygen demand is high and the air volume demand is low. Therefore, the circulating flue gas oxygen content needs to be above 18%, and the air volume is about 50% of the average air volume.

[0044] The middle 1 / 3-2 / 3 length of the sintering machine is the sintering stable stage. The sintering reaction mainly occurs in the middle of the material layer. Due to the existence of the combustion layer and the over-humidified layer, the air permeability of the material layer is poor, but the combustion is relatively stable. The air volume and oxygen demand are low. The oxygen content of the circulating flue gas is above 16%, and the air volume is 50%-100% of the average air volume.

[0045] The rear 2 / 3-1 length of the sintering machine is the end stage of sintering. The sintering reaction mainly occurs at the bottom of the material layer. At this time, the over-wet layer and the original material layer disappear, the permeability of the material layer improves, the combustion reaction ends, the oxygen demand is the lowest, the air volume demand is relatively high, the circulating flue gas oxygen content is above 10%, and the air volume is 100%-150% of the average air volume.

[0046] Based on the above findings, we set the circulating flue gas distribution main pipe 1 as a variable diameter structure to achieve preliminary air volume distribution according to the different air volume requirements in each stage, and added an oxygen-supplementing gas branch pipe 5 to the circulating flue gas distribution branch pipe 2 connected within the 1 / 3 length range of the front part of the sintering machine. An oxygen-supplementing gas inlet regulating valve 7 was installed at the inlet of the oxygen-supplementing gas branch pipe 5 to control the oxygen-supplementing gas flow rate. The oxygen-supplementing gas is quantitatively distributed directly in the circulating flue gas distribution branch pipe 2 at the outlet of the oxygen-supplementing gas branch pipe 5 to achieve step-by-step oxygen supply.

[0047] A conical flow guide device 6 is arranged in the circulating flue gas distribution branch pipe 2 at the outlet of the oxygen-supplementing gas branch pipe 5 to adjust the ratio of the circulating flue gas and the oxygen-supplementing gas, so as to realize high oxygen content and low air volume sintering. The conical flow guide device 6 can effectively adjust the circulating air volume and guide the oxygen-supplementing gas. The conical flow guide device 6 arranged at the outlet of the oxygen-supplementing gas branch pipe 5 has a cone top pointing to the circulating flue gas airflow direction, and the bottom facing the airflow direction. When the circulating flue gas volume increases, the bottom windward area is large, and the air volume of the circulating flue gas entering the flue gas sealing cover 3 can be effectively reduced by turbulence. According to the principle of pipeline interconnection, the excess circulating flue gas is automatically distributed into the circulating flue gas distribution branch pipe 2 that is not equipped with the conical flow guide device 6, that is, the circulating flue gas distribution branch pipe 2 with high air volume demand at the tail of the machine, thereby realizing automatic distribution of flue gas under large air volume. The outlet end of the oxygen-supplementing gas branch pipe 5 is directly opposite to the side of the conical flow guide device. The oxygen-supplementing gas is guided by the side angle of the flow guide device, and the airflow is more convenient to merge into the main flow direction of the circulating flue gas, avoiding the turbulence caused by the mixing of the two airflows, thereby avoiding pipeline vibration and wear. By combining the use of new flue gas distribution branches and traditional variable-diameter distribution structures, stepped air distribution and graded oxygen supply can be achieved in the length direction of the sintering machine, matching the sintering air and oxygen requirements as needed, thereby increasing the flue gas circulation ratio to more than 35%, and effectively avoiding flue gas overflow without affecting sintering production.

[0048] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0049] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation, characterized in that: include: A circulating flue gas distribution main pipe (1), the circulating flue gas distribution main pipe (1) comprising a plurality of stepped sections connected in sequence, wherein the pipe diameters of the plurality of stepped sections decrease in sequence along the direction in which the flue gas moves; The oxygen content requirements of the plurality of step sections arranged along the direction of flue gas movement increase successively, and the air volume requirements decrease successively; A circulating flue gas distribution branch pipe (2) is arranged in communication with one side of the corresponding step section; A smoke sealing cover (3) is connected to the gas outlet ends of the plurality of circulating smoke distribution branch pipes (2); An oxygen supplement device is arranged in the circulating flue gas distribution branch pipe (2) where the oxygen content needs to be increased; An oxygen supply device, connected to the air inlet end of the oxygen supplementation device; The oxygen supply device comprises an oxygen supply gas branch pipe (5), the oxygen supply gas branch pipe (5) is located below the corresponding circulating flue gas distribution branch pipe (2), the oxygen supply gas branch pipe (5) is obliquely inserted upward into the middle of the corresponding circulating flue gas distribution branch pipe (2), the gas outlet end of the oxygen supply gas branch pipe (5) is connected with the corresponding circulating flue gas distribution branch pipe (2), the gas outlet end of the oxygen supply gas branch pipe (5) is arranged close to the flue gas sealing cover (3), the gas inlet end of the oxygen supply gas branch pipe (5) is arranged close to the circulating flue gas distribution main pipe (1), and the gas inlet ends of a plurality of the oxygen supply gas branch pipes (5) are connected with the gas outlet end of the oxygen supply device; A conical flow guide device (6) is provided in the middle of the inner side of the circulating flue gas distribution branch pipe (2), the tip of the conical flow guide device (6) is arranged toward the flue gas sealing cover (3), and the gas outlet end of the oxygen supplementary gas branch pipe (5) is arranged toward the side wall of the conical flow guide device (6).

2. According to claim 1, a stepped air distribution, graded oxygen supplementation and high-proportion circulating flue gas distribution device is characterized in that: The oxygen supply device is provided in the circulating smoke distribution branch pipe (2) within the range of the end 1 / 3 of the length of the circulating smoke distribution main pipe (1) along the direction of smoke movement.

3. The high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation according to claim 1 is characterized in that: The oxygen supply device comprises an oxygen-supplementing gas main pipe (4), the side wall of which is in communication with the air inlet ends of a plurality of oxygen-supplementing gas branch pipes (5), and a regulating portion for regulating the oxygen flow rate is provided between the oxygen-supplementing gas main pipe (4) and the oxygen-supplementing gas branch pipes (5).

4. The high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation according to claim 3 is characterized in that: The regulating part comprises an oxygen-supplementing gas inlet regulating valve (7), one end of the oxygen-supplementing gas inlet regulating valve (7) being in communication with the side wall of the oxygen-supplementing gas main pipe (4), and the other end of the oxygen-supplementing gas inlet regulating valve (7) being in communication with the air inlet end of the oxygen-supplementing gas branch pipe (5).

5. The high-proportion circulating flue gas distribution device with stepped air distribution and graded oxygen supplementation according to claim 4 is characterized in that: The oxygen-supplementing gas inlet regulating valve (7) is a regulating single-plate valve, a butterfly valve or a plug-in valve.

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