A system and method for online measuring air leakage rate of sintering machine

Abstract

The present invention discloses a system and a measuring method for online measuring the air leakage rate of a sintering machine, and belongs to the field of sintering technology. The present invention uses a detection unit to sample the flue gas in the middle part below the grate bar of a trolley; the detection unit includes a plurality of exhaust pipes, a plurality of connecting pipes and an exhaust pump, one end of the exhaust pipe is inserted into a bellows, the other end of the exhaust pipe extends out of the bellows and is connected to the corresponding connecting pipe, the plurality of connecting pipes are connected to an exhaust pump, and the exhaust pump sends the extracted gas to the tube cavity for O2 content detection; a plurality of suction micropores are provided on the tube wall at one end of the exhaust pipe inserted into the bellows, the suction micropores are arranged at one end away from the grate bar, and the plurality of suction micropores are arranged at equal intervals along the length direction of the exhaust pipe, the end face of the exhaust pipe is sealed, and the structural design can effectively reduce the influence of smoke on subsequent detection, thereby improving the accuracy of the detection result.

Description

Technical Field

[0001] The present invention relates to the technical field of sintering, and more particularly to a system and a measuring method thereof for online measuring the air leakage rate of a sintering machine. Background Art

[0002] The exhaust sintering process is the main method of iron ore powder agglomeration at present, and is widely used in the metallurgical industry. During the sintering process, due to factors such as wear and aging of the sintering machine equipment, it will inevitably cause air leakage in the sintering machine system. The size of the air leakage is directly related to the power consumption of sintering production. The larger the air leakage, the higher the power consumption, and the smaller the air leakage, the lower the power consumption. At the same time, it also seriously affects the output of the sintering machine and the quality of the sintered ore. Data show that the air leakage rate of some foreign sintering machines has dropped below 30%, while the air leakage rate of domestic steel manufacturers is mostly between 45% and 60%. The practice of some foreign sintering plants has proved that for every 10% reduction in the air leakage rate of the sintering machine, the output of sintered ore can increase by 6%, the power consumption per ton of sintered ore can be reduced by 2KW / h, the use of coke powder can be reduced by 1kg per ton, and the iron ore yield rate can be increased by 1.5-2.0%.

[0003] The flue gas analysis method is the most commonly used method for detecting air leakage rate in the current sintering industry. The composition of the flue gas extracted from each measuring point is analyzed, and according to the law of conservation of matter, an equation is listed to maintain the total balance of the content of a certain component (O2, CO2) in the flue gas before and after the process, and the air leakage rate is indirectly calculated. In the prior art, in order to measure the air leakage rate of the sintering machine system, a common method is to organize manual work from time to time to extract the flue gas of the sintering process from the grate bars of the sintering machine trolley and the large flue in front of the inlet of the sintering main exhaust fan, analyze the O2 content in the flue gas, and calculate the air leakage rate of the sintering machine system.

[0004] However, the above measurement method is irregular and labor-intensive, and cannot be measured continuously. Therefore, the measurement results represent a limited timeliness, making it difficult to use for long-term analysis and guidance of sintering production, and even more difficult to provide an accurate basis for timely inspection and maintenance of the sintering machine system.

[0005] After searching, the Chinese patent number is: ZL 201921656262.8, the authorization announcement date is: June 23, 2020, and the name of the invention is: A real-time online monitoring system for the air leakage rate of a sintering machine. In this application, the upper sampling point of the bellows, the lower sampling point of the bellows and the main flue sampling point are respectively set at the upper and lower parts of the N bellows of the sintering machine and the main exhaust duct of the sintering machine, and the upper sampling pipe, the lower sampling pipe and the main flue sampling pipe are respectively connected, and the upper sampling pipe, the lower sampling pipe and the main flue sampling pipe are respectively connected to the gas composition analyzer, and the composition analyzer is provided with a sampling valve; the upper sampling pipe, the lower sampling pipe and the main flue sampling pipe are connected with a purge pipe, and the purge pipe is provided with a purge valve and connected to the purge gas source; the sampling valve and the purge valve are controlled by a computer control system.

[0006] Although the above application can also realize online monitoring of the air leakage rate of the sintering machine and replace manual sampling and detection, saving time and effort, the amount of flue gas and dust is large during the sintering process and the entire monitoring system works continuously. Therefore, in actual use, the sampling port is very likely to inhale a large amount of smoke and dust, which affects the accuracy of the air leakage rate detection and even blocks the sampling port. Summary of the invention

[0007] 1. Technical problem to be solved by the invention

[0008] The purpose of the present invention is to overcome the problem of inaccurate continuous measurement of the air leakage rate of a sintering machine in the prior art, and to provide a system for online measuring the air leakage rate of a sintering machine and a measurement method thereof; the present invention is provided with a detection unit 1 in the middle part below the grate bar, and the end of the detection unit 1 inserted into the bellows is provided with a plurality of air suction microholes, and the detection unit is arranged away from the grate bar, which can effectively reduce the influence of smoke on subsequent detection, thereby improving the accuracy of the detection result.

[0009] 2. Technical solution

[0010] In order to achieve the above object, the technical solution provided by the present invention is:

[0011] A system for online measurement of air leakage rate of a sintering machine of the present invention comprises a trolley, a bellows and a large flue, and is characterized in that: it also comprises a detection unit 1, which is used to sample the flue gas in the middle part below the grate bars of the trolley; the detection unit comprises a plurality of exhaust pipes, a plurality of connecting pipes and an exhaust pump, one end of the exhaust pipe is inserted into a bellows, the other end of the exhaust pipe extends out of the bellows and is connected to the corresponding connecting pipe, the plurality of connecting pipes are connected to an exhaust pump, and the exhaust pump delivers the extracted gas to the tube cavity for detection of O2 content;

[0012] A plurality of air intake micropores are provided on the tube wall of one end of the exhaust pipe inserted into the bellows. The air intake micropores are arranged at the end away from the grate bar, and the plurality of air intake micropores are arranged at equal intervals along the length direction of the exhaust pipe. The end face of the exhaust pipe is sealed.

[0013] As a further improvement of the present invention, a plurality of air suction microholes are symmetrically arranged about the central axis of the grate bar.

[0014] As a further improvement of the present invention, the diameter of the air suction micropores is 2.80-3.20 mm.

[0015] As a further improvement of the present invention, the vacuum degree of the vacuum pump is 4.80-5.20 kPa

[0016] As a further improvement of the present invention, a zirconium oxide O2 content analyzer probe is installed in the tube cavity.

[0017] As a further improvement of the present invention, a solenoid valve is installed on each connecting pipe.

[0018] As a further improvement of the present invention, it also includes two detection units 2, and the detection unit 2 has the same structural design as the detection unit 1. The large flue includes a large flue A and a large flue B. One of the detection units 2 is used to sample the flue gas of the bellows branch connected to the large flue A; the other detection unit 2 is used to sample the flue gas of the bellows branch connected to the large flue B.

[0019] As a further improvement of the present invention, a flow meter is installed on the branch pipe of each wind box.

[0020] A measuring method of a system for online measuring the air leakage rate of a sintering machine, using the above-mentioned system for online measuring the air leakage rate of a sintering machine, the process is as follows:

[0021] Taking the 1# bellows as an example, the exhaust pump of the detection unit 1 is started, so that the flue gas in the middle part below the grate bar moves along the exhaust pipe to the tube cavity, and the O2 content is detected by the zirconium oxide O2 content analyzer probe to obtain O 2(测点1)1 ;

[0022] Then, the suction pump of the second detection unit is started, so that the flue gas in the bellows branch pipe moves along the suction pipe to the tube cavity, and the O2 content of the flue gas in the corresponding bellows branch pipe is detected by the zirconium oxide O2 content analyzer probe to obtain the O2 content of measuring point 2: 2(A1)1 , O2 content at measuring point 3: O 2(B1)1 At the same time, the flow meter in the wind box branch pipe at the measuring point measures the air flow in the branch pipe to obtain Q (A)1 , Q (B1)1 ;

[0023] Finally, the air leakage rate of the 1# bellows branch pipe is obtained as follows:

[0024]

[0025] By analogy, the air leakage rates at different air box branches of 2#, 3#...N# air boxes are obtained according to the above detection process, namely:

[0026]

[0027]

[0028] And the corresponding branch air flow Q (A)N , Q (B1)N ;

[0029] Calculate the total amount of original flue gas drawn into the wind box at the grate bars corresponding to each wind box as:

[0030] Q 1Σ =Q (A1)1 ×(1-k (A1)1 )+Q (B1)1 ×(1-k (B1)1 )

[0031] …

[0032] Q NΣ =Q (A1)N ×(1-k (A1)N )+Q (B1)N ×(1-k (B1)N )

[0033] Then calculate the total amount of O2 in the original flue gas drawn into the wind box from the grate bars corresponding to each wind box:

[0034] Q (O2量)1 =[Q (A1)1 ×(1-k (A1)1 )+Q (B1)1 ×(1-k (B1)1 )]×O 2(测点1)1

[0035] …

[0036] Q (O2量)N =[Q (A1)N ×(1-k (A1)N )+Q (B1)N ×(1-k (B1)N )]×O 2(测点1)N

[0037] The average O2 content of all flue gas drawn into the wind box at the grate bars of the trolley is:

[0038]

[0039] The average O2 content of the total flue gas at measuring point 2 is:

[0040]

[0041] The average O2 content of the total flue gas at measuring point 3 is:

[0042]

[0043] The average air leakage rates from measuring point 1 to measuring point 2 and from measuring point 1 to measuring point 3 are calculated as follows:

[0044]

[0045]

[0046] The average O2 content data obtained from the flue gas measurement data measured at the dust collector, namely measurement point 4 and measurement point 5, are recorded as: O 2(A2) , O 2(B2) ;

[0047] Then, the air leakage rate of the A series of large flues in the sintering system is:

[0048]

[0049] The air leakage rate of the B series of the large flue of the sintering system is:

[0050]

[0051] The total average air leakage rate of the system is:

[0052]

[0053] 3. Beneficial effects

[0054] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects:

[0055] (1) The system for online measuring the air leakage rate of a sintering machine of the present invention can effectively reduce the influence of smoke on subsequent detection by providing a detection unit 1 in the middle part below the grate bar, and the end of the detection unit 1 inserted into the wind box is provided with a plurality of air suction micro holes, and is arranged away from the grate bar, thereby improving the accuracy of the detection result; in addition, the whole device has a simple structural design and is easy to operate;

[0056] (2) The system for online measurement of the air leakage rate of a sintering machine of the present invention designs the layout of the air suction micropores so that the sampling is more representative, thereby ensuring the accuracy of the subsequent air leakage rate calculation; in addition, the diameter of the air suction micropores is limited to avoid the inhalation of larger smoke particles, which affects the accuracy of the detection results, and at the same time ensures that smaller smoke particles can enter the exhaust pipe, thereby avoiding the blockage of the air suction micropores and affecting the measurement results;

[0057] (3) The system for online measurement of the air leakage rate of a sintering machine of the present invention controls the vacuum degree of the vacuum pump so that sampling can be performed uniformly and stably during the sampling process, thereby minimizing the impact on the entire sintering system; an electromagnetic valve is installed on the connecting pipe, and the electromagnetic valve is used to control the interruption of the air flow in the connecting pipe, which is beneficial for a zirconia O2 content analyzer probe to continuously detect different bellows without affecting the detection process and the detection results.

[0058] (4) The present invention provides a method for measuring the online leakage rate of a sintering machine. Different detection units are used to detect different positions and areas. At the same time, the detected data is used in conjunction with a flow meter to make the final result more accurate. The detection result can be combined with relevant sintering process operation data to conduct quantitative comparative analysis of sintering production in different periods. In addition, it can provide a basis for timely inspection and maintenance of the sintering machine system, which is beneficial to optimize the production process operation, timely reduce the leakage of the sintering machine system, and achieve the purpose of reducing the power consumption of the sintering system. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the circulation of sintering flue gas during sintering in the prior art;

[0060] Figure 2 It is a schematic diagram of the positions of the measuring points of the present invention;

[0061] Figure 3 It is a schematic cross-sectional structure diagram of the sintering trolley of the present invention;

[0062] Figure 4 It is a structural schematic diagram of a detection unit 1 for detecting a measurement point 1 in the present invention;

[0063] Figure 5 It is a structural schematic diagram of the detection unit 2 used for detecting the measuring point 2 or the measuring point 3 in the present invention;

[0064] Explanation of the symbols in the schematic diagram:

[0065] 10. Trolley; 20. Bellows; 30. Main flue; 31. Main flue A; 32. Main flue B; 40. Dust collector; 50. Main exhaust fan; 60. Chimney;

[0066] 71. Air extraction pipe; 72. Connecting pipe; 73. Solenoid valve; 74. Filter; 75. Air extraction pump; 76. PLC controller; 77. Lumen. DETAILED DESCRIPTION

[0067] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0068] Example

[0069] A system for online measurement of air leakage rate of a sintering machine according to this embodiment, such as Figure 1 As shown, it includes a trolley 10, a bellows 20, a large flue 30, a dust collector 40, a main exhaust fan 50 and a chimney 60 which are connected in sequence through pipelines. During the sintering process, the smoke generated by the sintering finally moves along the various components to the chimney 60 and is discharged to the outside through the chimney 60.

[0070] For sintering, the air leakage rate is very important. In this embodiment, in order to facilitate the measurement of the entire sintering system, Figure 2 As shown, multiple measuring points are set in the whole sintering system, wherein measuring point 1 is located in the middle below the grate bar, that is, in the middle of the upper horizontal surface in the wind box 20 and close to the bottom beam of the trolley;

[0071] Another measuring point is located in the branch pipe of the wind box 20, that is, in the pipe between the wind box 20 and the large flue 30. The large flue 30 of this embodiment is as shown in FIG. Figure 3 As shown, the large flue 30 includes a large flue A31 and a large flue B32. Therefore, for the convenience of explanation, the pipe between the large flue A31 and the wind box 20 is the measuring point 2, and the measuring point 3 is located in the pipe between the large flue B32 and the wind box 20.

[0072] It is worth noting that the above-mentioned measuring points 1, 2 and 3 refer to specific positions. In the entire sintering system, the wind box 20 itself is provided with multiple positions, such as Figure 4 and Figure 5 , 1#, 2#, 3#...N-2#, N-1#, N# all refer to the number of bellows 20, therefore, measuring point 1, measuring point 2, measuring point 3 can be considered as multiple measuring points.

[0073] Since the large flue A31 and the large flue B32 are two flue gas passages, and each passage is provided with a corresponding dust collector 40 and a main exhaust fan 50, in order to more accurately measure the air leakage rate of the entire system, a measuring point 4 is provided behind the dust collector 40 connected to the large flue A31, and a measuring point 5 is provided behind the dust collector 40 connected to the large flue B32.

[0074] For measuring point 4 and measuring point 5, corresponding detection devices have been provided there in the prior art for detecting the content of each component of the flue gas after dust removal.

[0075] Combination Figure 3 and Figure 4 In this embodiment, a detection unit is provided to sample the flue gas in the middle part below the grate bar of a pair of trolleys 10, that is, to detect the measuring point 1. The detection unit includes a plurality of exhaust pipes 71, a plurality of connecting pipes 72 and an exhaust pump 75. The number of the exhaust pipes 71 in the detection unit corresponds to the number of the bellows 20, and one end of the exhaust pipe 71 is inserted into the corresponding bellows 20, and the other end of the exhaust pipe 71 extends out of the bellows 20 and is connected to the corresponding connecting pipe 72, and the connecting pipe 72 is connected to an exhaust pump 75; due to the presence of a plurality of bellows 20, a plurality of connecting pipes 72 are connected to an exhaust pump 75, such as Figure 4 As shown; the vacuum pump 75 delivers the extracted gas to the lumen 77 for O2 content detection.

[0076] Preferably, a zirconium oxide O2 content analyzer probe is installed in the tube cavity 77 of this embodiment, and the oxygen content of the extracted sample is detected by the zirconium oxide O2 content analyzer probe.

[0077] In order to prevent the installation of the detection unit from affecting the air leakage rate of the entire system, the contact area between the exhaust pipe 71 and the bellows 20 is sealed by welding.

[0078] Furthermore, in order to ensure the accuracy of the air leakage rate detection of the entire system, a plurality of air intake micropores are opened on the pipe wall at one end of the exhaust pipe 71 inserted into the bellows 20, and the air intake micropores are arranged at the end away from the grate bars. The flue gas generated during sintering flows toward the bellows 20 under the action of the main exhaust fan 50. Due to the existence of the exhaust pipe 71 itself, the air flow moves downward along the outer wall of the exhaust pipe 71. Therefore, large particles in the flue gas have little effect on the air intake micropores located below the exhaust pipe 71, and the large particles will continue to move downward, thereby preventing large particles from entering the air intake micropores or clogging the air intake micropores, thereby ensuring the accuracy of the oxygen content detection results.

[0079] In this embodiment, a plurality of air suction microholes are arranged at equal intervals along the length direction of the air suction pipe 71 .

[0080] Preferably, in order to further prevent large particles from moving into the air intake micropores, the end face of the air extraction pipe 71 is sealed, and only the gas absorbed by the air intake micropores is tested during detection; in addition, multiple air intake micropores are symmetrically arranged about the central axis of the grate bar, and the diameter of the air intake micropores is 2.80-3.20 mm, and the diameter of the air intake micropores in this embodiment is 3.0 mm. By designing the layout of the air intake micropores, the sampling is more representative, thereby ensuring the accuracy of the subsequent air leakage rate calculation; at the same time, limiting the diameter of the air intake micropores can avoid the inhalation of larger smoke particles, which affects the accuracy of the test results, and can also ensure that smaller smoke particles can enter the air extraction pipe 71, avoiding the blockage of the air intake micropores and affecting the measurement results.

[0081] Since the detection unit 1 needs to detect different bellows 20 , in order to avoid mutual influence between sampling and detection, a solenoid valve 73 is installed on each connecting pipe 72 , and the solenoid valve 73 controls the opening and closing of the connecting pipe 72 .

[0082] Preferably, in this embodiment, the solenoid valve 73 is a normally closed solenoid valve, which is controlled by a PLC controller 76 .

[0083] In addition, when the vacuum pump 75 is working, its vacuum degree is controlled at 4.80-5.20 kPa. Preferably, the vacuum degree of this embodiment is controlled at 5.0 kPa.

[0084] The vacuum pump 75 of this embodiment pumps the flue gas from the 1#~N# bellows 20 to the probe equipped with the zirconium oxide O2 content analyzer according to the sequential control sequence, thereby realizing the alternating and continuous measurement of the real-time O2 content of the flue gas at the measuring point 1. The measured flue gas enters the large flue 30 along the pipeline.

[0085] In order to further improve the accuracy of the detection results, when detecting the smoke extracted by different bellows 20, it is necessary to control the detection interval time. Due to the different lengths of the connecting tube 72 itself and the smoke from the last detection remaining in the tube cavity 77, this situation is adjusted according to actual production and use. In this embodiment, the detection time interval between two adjacent bellows 20 is controlled at 2-4s.

[0086] In order to prevent the dust in the smoke from affecting the detection result, a filter 74 is installed between the vacuum pump 75 and the electromagnetic valve 73 to filter the dust.

[0087] Similarly, combined Figure 3 and Figure 5 A detection unit 2 is used to detect measuring point 2 and measuring point 3 respectively. The structural design of the detection unit 2 is the same as that of the detection unit 1. One detection unit 2 is used to sample the flue gas from the 20 branch pipes of the bellows connected to the large flue A31, so as to detect the oxygen content at measuring point 2; the other detection unit 2 is used to sample the flue gas from the 20 branch pipes of the bellows connected to the large flue B32, so as to detect the oxygen content at measuring point 3.

[0088] In addition, a flow meter is installed on the branch pipe of each wind box 20, and the air flow rate flowing through the corresponding branch pipe is detected by the flow meter.

[0089] By measuring the positions of different measuring points and processing the measured data accordingly, the air leakage rate of each wind box 20 and the entire sintering system is obtained, so as to detect the entire system and each area and guide production, thereby improving the quality of sintered products.

[0090] The measuring method of a system for online measuring the air leakage rate of a sintering machine in this embodiment adopts the above-mentioned system for online measuring the air leakage rate of a sintering machine, and the process is as follows:

[0091] Assume that the sintering mixture starts from the ignition of the material surface and sintering downwards until all the sintering is ore, and the time required is t; the effective length of the sintering machine is L (m), and the current speed of the sintering machine is v (m / s). Then:

[0092]

[0093] Wherein, t represents the air leakage rate measurement cycle time, that is, the air leakage rate can be measured once every t time period.

[0094] Assume that the sintering machine has N wind boxes 20, and the effective length of each wind box 20 is L1, L2, ... L N The opening time of the solenoid valve 73 of each wind box 20 is t1, t2...t N ,but:

[0095]

[0096] …

[0097]

[0098] Assuming that the sampling frequency of the zirconia O2 content analyzer probe is η (Hz), the number of O2 content data samples corresponding to measuring point 1, measuring point 2 (A1), and measuring point 3 (B1) is m1, m2, ... m N ,but:

[0099] m1=(t1-t 1延 )×η

[0100] …

[0101] m N =(t N -t N延 )×η

[0102] Among them, t 1延 ……t N延 The time required for the flue gas at each measuring point to flow from the exhaust pipe port to the tube cavity 77, that is, the data during the period when the gas to be measured in each bellows 20 flows from the exhaust pipe port to the tube cavity 77 needs to be discarded (this stage is the gas left over from the previous measurement cycle), so "solenoid valve opening time + t N延 " is the starting time for valid data sampling and recording.

[0103] The effective sampling value of the flue gas O2 content near the grate bars of each wind box 20 (measurement point 1) is recorded as O 2(箱1)i ...O 2(箱N)i , then the average O2 content of each wind box 20 at measuring point 1 is:

[0104]

[0105] …

[0106]

[0107] Similarly, each valid sampling value at A1 and B1 is recorded as O 2(A1测)i ...O 2(AN测)i , O 2(B1测)i ...O 2(BN测)i, the average O2 content corresponding to each wind box 20 at A1 (measurement point 2) can be calculated and recorded as:

[0108]

[0109] …

[0110]

[0111] The data sampling of the measuring point 2 needs to be delayed by about 1s to 2s compared with the corresponding measuring point 1, that is, the time required for the flue gas at the grate bars of the trolley to flow to the corresponding wind box branch pipe measuring point.

[0112] Similarly, the average O2 content of B1 (measurement point 3) is calculated and recorded as:

[0113]

[0114] …

[0115]

[0116] The data sampling of the measuring point 3 needs to be delayed by about 1s to 2s compared with the corresponding measuring point 1, that is, the time required for the flue gas at the grate bars of the trolley to flow to the corresponding wind box branch pipe measuring point.

[0117] In the above process, i in the formula is the sequence number of the sampling value.

[0118] According to the above measurement data, the air leakage rate from the trolley 10 to each bellows branch on each side, that is, the air leakage rate of the trolley bellows branch, can be calculated in real time, which are:

[0119]

[0120] …

[0121]

[0122]

[0123] …

[0124]

[0125] The opening time t1, t2, ..., t of the solenoid valve 73 corresponding to each wind box 20 N , the air flow rate of each bellows branch on each side is measured synchronously and the average value is calculated. Assume that the air flow rate of each bellows branch on each side is Q (A1)1 ,……,Q (A1)N , Q (B1)1 ,……,Q (B1)N .

[0126] The total amount of original flue gas drawn into the wind box at the grate bars corresponding to each wind box 20 is calculated as:

[0127] Q 1Σ =Q (A1)1 ×(1-k (A1)1 )+Q (B1)1 ×(1-k (B1)1 )

[0128] …

[0129] Q NΣ =Q (A1)N ×(1-k (A1)N )+Q (B1)N ×(1-k (B1)N )

[0130] Then calculate the total amount of O2 in the original flue gas drawn into the wind box from the grate bars corresponding to each wind box 20:

[0131] Q (O2量)1 =[Q (A1)1 ×(1-k (A1)1 )+Q (B1)1 ×(1-k (B1)1 )]×O 2(测点1)1

[0132] …

[0133] Q (O2量)N =[Q (A1)N ×(1-k (A1)N )+Q (B1)N ×(1-k (B1)N )]×O 2(测点1)N

[0134] The average O2 content of all the flue gas drawn into the wind box 20 at the grate bars of the trolley 10 is:

[0135]

[0136] The average O2 content of the total flue gas at measuring point 2 is:

[0137]

[0138] The average O2 content of the total flue gas at measuring point 3 is:

[0139]

[0140] The average air leakage rates from measuring point 1 to measuring point 2 and from measuring point 1 to measuring point 3 are calculated as follows:

[0141]

[0142]

[0143] The flue gas measurement data measured at the dust collector 40, namely, the measurement points 4 and 5, whose sampling time is consistent with the above leakage rate measurement sampling time, obtain the average O2 content data, which are recorded as: O 2(A2) , O 2(B2) ;

[0144] Then, the air leakage rate of the A31 series of the sintering system large flue is:

[0145]

[0146] The air leakage rate of the B32 series of large flue in the sintering system is:

[0147]

[0148] Therefore, the total average air leakage rate of the system is:

[0149]

[0150] Through the above process, the air leakage rate of the entire sintering system and each wind box 20 can be obtained more accurately and timely. By combining the results with relevant sintering process operation data, quantitative comparative analysis of sintering production in different periods can be carried out. In addition, it can provide a basis for timely inspection and maintenance of the sintering machine system, which is conducive to optimizing the production process operation, timely reducing the air leakage of the sintering machine system, and achieving the purpose of reducing the power consumption of the sintering system.

[0151] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A method for measuring the air leakage rate of a sintering machine online, using a system for measuring the air leakage rate of a sintering machine online, characterized in that: The system for online measuring the air leakage rate of a sintering machine comprises a trolley (10), a bellows (20) and a large flue (30), and is characterized in that: it also comprises a detection unit 1, which is used to sample the flue gas in the middle part below the grate bars of the trolley (10); the detection unit comprises a plurality of exhaust pipes (71), a plurality of connecting pipes (72) and an exhaust pump (75), one end of the exhaust pipe (71) is inserted into a bellows (20), the other end of the exhaust pipe (71) extends out of the bellows (20) and is connected to the corresponding connecting pipe (72), the plurality of connecting pipes (72) are connected to an exhaust pump (75), and the exhaust pump (75) delivers the extracted gas to the tube cavity (77) for detecting the O2 content; A plurality of air suction micropores are provided on the tube wall of one end of the air suction pipe (71) inserted into the wind box (20), the air suction micropores are arranged at the end away from the grate bar, and the plurality of air suction micropores are arranged at equal intervals along the length direction of the air suction pipe (71), and the end face of the air suction pipe (71) is sealed; The specific measurement process is: Taking the 1# wind box (20) as an example, the exhaust pump (75) of the detection unit 1 is started, so that the flue gas in the middle part below the grate bar moves along the exhaust pipe (71) to the tube cavity (77), and the O2 content is detected by the zirconium oxide O2 content analyzer probe to obtain O 2(测点1)1 ; Then, the suction pump (75) of the second detection unit is started, so that the smoke in the branch pipe of the bellows (20) moves along the suction pipe (71) to the tube cavity (77), and the O2 content of the smoke in the corresponding branch pipe of the bellows (20) is detected by the probe of the zirconium oxide O2 content analyzer to obtain the O2 content of the measuring point 2: 2(A1)1 , O2 content at measuring point 3: O 2(B1)1 At the same time, the flow meter in the wind box (20) branch pipe at the measuring point measures the air flow in the branch pipe to obtain Q (A)1 , Q (B1)1 ; Finally, the air leakage rate of the branch pipe of the 1# wind box (20) is obtained as follows: By analogy, the air leakage rates at the branch pipes of the 2#, 3#, ... N# wind boxes (20) are obtained according to the above detection process, namely: And the corresponding branch air flow Q (A)N , Q (B1)N ; The total amount of original flue gas drawn into the wind box at the grate bars corresponding to each wind box (20) is calculated as: Q 1Σ =Q (A1)1 ×(1-k (A1)1 )+Q (B1)1 ×(1-k (B1)1 ) …… Q NΣ =Q (A1)N ×(1-k (A1)N )+Q (B1)N ×(1-k (B1)N ) Then the total amount of O2 in the original flue gas drawn into the wind box from the grate bars corresponding to each wind box (20) is calculated as: …… The average O2 content of all the flue gas drawn into the wind box (20) from the grate bars of the trolley (10) is: The average O2 content data obtained by measuring the flue gas at the dust collector (40), i.e., measuring point 4 and measuring point 5, are recorded as: 2(A2) , O 2(B2) ; Then, the air leakage rate of the sintering system large flue A (31) series is: The air leakage rate of the sintering system large flue B (32) series is: The total average air leakage rate of the system is:

2. The measuring method according to claim 1, characterized in that: A plurality of air suction microholes are symmetrically arranged about the central axis of the grate bar.

3. The measuring method according to claim 2, characterized in that: The diameter of the air suction micropores is 2.80-3.20 mm.

4. The measuring method according to claim 3, characterized in that: The vacuum degree of the vacuum pump (75) is 5 kPa.

5. The measuring method according to claim 4, characterized in that: A zirconium oxide O2 content analyzer probe is installed in the tube cavity (77).

6. The measuring method according to claim 5, characterized in that: A solenoid valve (73) is installed on each connecting pipe (72).

Images