JP6036267B2 - How to identify the location of the air leak in the sintering machine pallet - Google Patents

Description

  The present invention relates to a method for identifying a location of air leakage in a pallet of a Dwightroid (DL) type sintering machine that sinters sintered raw materials such as iron ore and carbonaceous material.

  Conventionally, sintered raw materials such as iron ore and carbonaceous materials are sintered with a DL-type sintering machine to produce sintered ore charged into a blast furnace.

  As shown in FIG. 1, the DL-type sintering machine is connected endlessly between two sprockets 5 and rotates around the pallet 1 (in the direction of the arrow in the figure). A hopper 3 for charging a sintered raw material such as a layer, an ignition furnace 4 for igniting the sintered raw material deposited on the pallet, and air under the pallet 1 is sucked through the sintered layer and the raw material layer. It consists of a windbox 2. The wind box 2 is connected to a single intake pipe 6.

  An air seal plate (not shown) that maintains airtightness between the wind box 2 and the pallet 1 is attached to the upper end of the wind box 2. The lower end of the pallet 1 slides on the air seal plate to maintain airtightness. However, since the air seal plate is worn, a gap is formed between the wind box 2 and the pallet 1, and the outside air enters the wind box 2. To do. That is, air leakage occurs between the wind box 2 and the pallet 1.

  Leakage also occurs on the pallet 1. When the pallet is worn, air leakage is generated in the pallet itself, and the gap between adjacent pallets is expanded due to wear and the air leakage is generated.

The air leakage generated in the sintering machine adversely affects the progress of the sintering and leads to a decrease in productivity. Therefore, it is important to detect the location of the air leakage and take measures. Therefore, various air leakage detection methods have been proposed so far (for example, see Patent Documents 1 to 5).

  For example, Patent Document 5 discloses that the oxygen concentration and temperature are measured on the upstream side and the downstream side of the exhaust gas flow of the exhaust gas treatment system of the sintering machine, and the leakage state is detected from the difference in oxygen concentration or the difference in temperature. A characteristic air leakage detection method is disclosed.

  The air leak detection method of Patent Document 5 (a) can measure the air leak rate with high accuracy and can quantify the amount of air leak, which makes the judgment of equipment repair accurate. (B) Small amount of air leak (initial air leak) It is possible to find the location of the air leak and take immediate measures, and (c) the air leakage rate is greatly reduced and the power cost of the exhaust gas suction blower is reduced. Since the oxygen concentration must be measured over a wide range, it is difficult to identify the location of the pallet where the air leaks.

  A certain amount of air required for the sintering reaction is required to perform the sintering accurately on the rotating pallet. However, if air leakage occurs in the sintering machine, ensure the necessary amount of air. The sintering reaction becomes unstable and the quality of the sintered ore becomes non-uniform.

  As described above, the air leakage occurs not only on the sliding portion of the air seal plate but also on the pallet itself and the adjacent portion. According to the applicant's findings, 20-50% of the air leakage is due to pallet wear.

  However, the conventional air leak detection does not distinguish between the air leak locations and detects the total amount of air leaks occurring at the air leak locations, and does not contribute to accurate control of sintering on the pallet.

  In view of this point, the applicant has proposed a leak detection device that detects a leak generated in a pallet (see Patent Documents 6 and 7). In the air leak detection devices of Patent Documents 6 and 7, a laser oximeter is arranged at a predetermined position directly above the pallet in the upper part of the wind box, and the pallet that is leaking air is identified based on the measured oxygen concentration and the pallet position. Is.

JP 56-105436 A JP 58-189337 A JP 60-48484 A JP-A 61-195929 JP-A-6-300459 JP 2009-275239 A JP 2010-007904 A

  As described above, the air leakage of the sintering machine also occurs on the pallet itself. Since air leakage adversely affects the progress of sintering and leads to a decrease in productivity, it is important to take appropriate measures by accurately detecting air leakage generated in the pallet itself.

  The present invention measures the oxygen concentration in the pallet width (width in the wrapping direction of the pallet) direction of the sintered gas sucked through the sintered layer and raw material layer with a laser-type oximeter placed at the top of the window box. Then, it is an object of the present invention to provide a method for identifying a wind leak location that solves the problem by identifying a location of a wind leak in the pallet from a change in oxygen concentration in the pallet width direction.

  The present inventors diligently studied a method for identifying the location of the air leakage in the width direction of the pallet. As a result, if (i) the oxygen concentration in the pallet width direction is continuously measured and displayed for each pallet with a laser oximeter, (ii) the air leakage in the pallet from the change in the oxygen concentration in the pallet width direction It was found that the location can be specified.

  Further, the present inventors have found that the degree of wear of the pallet can be estimated based on the maximum difference in oxygen concentration at the location of the air leakage, and the time for repairing or replacing the pallet can be determined.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

(1) In a method for identifying an air leak location in a sintering machine pallet by measuring an oxygen concentration in a combustion gas sucked by a wind box,
(I) A laser oximeter provided at the top of the window box continuously measures the oxygen concentration in the pallet width direction of the combustion gas immediately below the pallet that circulates and passes over the laser oximeter. Identify the pallet,
(Ii) When displaying the measured oxygen concentration in the pallet width direction for each identified pallet and specifying the location of the air leakage from the increased oxygen concentration position ,
(Ii-1) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oe (%) at the end of the pallet width direction are calculated. When the following formula (1) is satisfied, the end of the pallet is specified as the location of air leakage and / or
(Ii-2) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oz of the portion other than the end portion in the pallet width direction are calculated. When (%) satisfies the following formula (2), the location is identified as the location of the air leakage location.
Oe−Om ≧ Ae (1)
Ae: Constant determined by operational performance
Oz−Om ≧ Az (2)
Az: Constant determined by operation results

  (2) The identification method of the air leakage location of the sintering machine pallet according to (1), wherein the pallet is identified by an electronic information device attached to a side of the pallet.

( 3 ) The method for identifying a leakage location in a sintering machine pallet according to (1) or (2) , wherein the time for repair or replacement of the pallet is determined based on the oxygen concentration of the leakage location.

  According to the present invention, in the pallet width direction of the sintering machine pallet, it is possible to identify the location of the air leak, and further, based on the oxygen concentration of the location of the air leak, estimate the degree of wear of the pallet, The time for replacement can be determined. As a result, during operation of the sintering machine, it is possible to stably secure the air necessary for sintering the sintering raw material and continue the stable sintering operation.

It is a figure which shows the basic aspect of a sintering machine. It is a figure which shows the aspect of the sintering machine which provided the laser type oxygen concentration meter in the upper part of the wind box. (A) shows the upper surface aspect of a sintering machine (a raw material supply hopper and an ignition furnace are not shown in figure), (b) shows the side surface aspect of a sintering machine. It is a figure which shows the AA cross section of Fig.2 (a). It is a figure which shows an example of the oxygen concentration for every measured pallet. It is a figure which shows typically the relationship between oxygen concentration and a leak location. It is a figure which shows the location which has a possibility of an air leak in the cross section of a pallet. The average oxygen concentration Om (%), the oxygen concentration Oe (%) at the pallet width direction end, and the oxygen concentration Oz (%) at locations other than the pallet width direction end in the oxygen concentration in the pallet width direction are schematically shown. FIG. It is a figure which shows the oxygen concentration of the pallet width direction measured in the Example.

The method for identifying the location of air leakage in the sintering machine pallet of the present invention (hereinafter sometimes referred to as the “method of the present invention”) measures the oxygen concentration in the combustion gas sucked by the wind box at the location of air leakage in the sintering machine pallet. In the identification method,
(I) A laser oximeter provided at the top of the window box continuously measures the oxygen concentration in the pallet width direction of the combustion gas immediately below the pallet that circulates and passes over the laser oximeter. Identify the pallet,
(Ii) When displaying the measured oxygen concentration in the pallet width direction for each identified pallet and specifying the location of the air leakage from the increased oxygen concentration position,
(Ii-1) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oe (%) at the end of the pallet width direction are calculated. When the following formula (1) is satisfied, the end of the pallet is specified as the location of air leakage and / or
(Ii-2) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oz of the portion other than the end portion in the pallet width direction are calculated. When (%) satisfies the following formula (2), this point is specified as a wind leak point .
Oe−Om ≧ Ae (1)
Ae: Constant determined by operational performance
Oz−Om ≧ Az (2)
Az: Constant determined by operation results

  Hereinafter, the method of the present invention will be described with reference to the drawings.

  FIG. 2 shows an embodiment of a sintering machine in which a laser oximeter is provided on the upper part of the window box. The sintering machine shown in FIG. 2 has basically the same structure as the sintering machine shown in FIG. FIG. 2A shows a top view of the sintering machine (raw material supply hopper 3 and ignition furnace 4 are not shown), and FIG. 2B shows a side view of the sintering machine. The laser oxygen concentration meter 7 can measure the oxygen concentration in the pallet width direction of the rotating pallet.

  In the sintering machine shown in FIG. 2, a laser oximeter 7 is arranged on the upper part of the window box 2 close to the ignition furnace 4. The laser oximeter 7 includes a light emitter 9 and a light receiver 10, and the light receiver 10 is connected to an oxygen concentration display device 8.

  FIG. 2 shows a mode in which the laser oximeter 7 is arranged in the wind box 2 close to the ignition furnace 4, but in the present invention, the oxygen concentration capable of detecting the location of the air leakage in the pallet width direction of the pallet. Therefore, the position of the laser oximeter is not limited to a specific window box. However, since the air leakage diffuses, it is preferable to place the laser oximeter close to the pallet in order to accurately detect the location of the air leakage.

  The number of laser oximeters to be arranged may be one as long as the oxygen concentration in the pallet width direction can be measured and the location of the air leak can be detected. However, in order to improve the detection reliability, two or more laser oximeters may be arranged. Good.

  FIG. 3 shows an AA cross section of FIG. The pallet 1 is composed of a bottom portion on which the great bars 1a are arranged and a side portion 1b, in which a sintering raw material 15 is accommodated. The pallet 1 includes wheels 11 on both outer sides of the side portion 1b. The wheel 11 rolls on the rail 12 supported by the gantry 12a provided on the outer frame 13 attached to the outside of the upper side wall 2a of the wind box 2, and the pallet 1 circulates.

The lower end portion of the pallet 1 slides on the air seal plate 14 attached to the upper end surface of the upper side wall 2a of the wind box 2 while maintaining the airtightness as the pallet 1 turns.
On the upper side wall 2 a of the wind box 2, a light emitter 9 that emits infrared laser light L and a light receiver 10 that receives the laser light L that has traversed the wind box 2 are arranged, and a laser oximeter 7 is configured. ing.

  With the laser oxygen concentration meter 7, the oxygen concentration of the sintering gas sucked by the wind box 2 is measured directly under the pallet 2. As described above, the position immediately below the pallet for measuring the oxygen concentration is preferably closer to the pallet bottom. The oxygen concentration measured by the laser oxygen concentration meter 7 is transmitted to the oxygen concentration display device 8 (see FIG. 2A) and displayed on the screen. This display will be described later.

  An electronic device 16 containing pallet identification information is attached to the side 1 b of the pallet 1 in order to identify the pallet 1 that passes over the laser oximeter 7. An ID tag may be used as the electronic device 16. In addition, as the electronic device 16, a barcode (one-dimensional code) and various two-dimensional codes (commercially available codes such as QR code (registered trademark) and CP code) can be used. Non-contact magnetic cards, ID tags, and IC tags can also be used.

  The pallet identification information read from the electronic device 16 by the reading sensor 17 is transmitted to the oxygen concentration display device 8 (see FIG. 2A). The measured oxygen concentration in the pallet width direction is displayed on the display screen of the oxygen concentration display device 8 for each pallet based on the pallet identification information.

FIG. 4 shows an example of the oxygen concentration measured for each pallet. The following can be understood from FIG.
(A) The oxygen concentration in the pallet width direction is different for each pallet.
(B) The oxygen concentration is high in the pallet and the adjacent part of the pallet.
(C) The oxygen concentration in the pallet and the adjacent part of the pallet is different for each adjacent part.
(D) There is a pallet with a high oxygen concentration at the center of the pallet.

  Although the pallet is worn by the sintering operation, the degree and location of wear differ between pallets, and as a result, it is assumed that the oxygen concentration in the pallet width direction is different for each pallet.

  It is inevitable that a certain amount of air leakage will occur at the pallet and the adjacent part of the pallet, and the oxygen concentration will be high, but at the pallet adjacent part where the oxygen concentration is extremely high, the gap will expand due to wear of the pallet edge, It is estimated that a large air leak has occurred. In a pallet with a high oxygen concentration at the center of the pallet, it is presumed that air leakage occurs at the center.

  Based on the above, FIG. 5 schematically shows the relationship between the oxygen concentration and the location of the air leakage. The place where the oxygen concentration is high is the place where the air leaks.

Air leakage occurs in the adjacent portion xy between the pallet 1x and the pallet 1y and in the adjacent portion yz between the pallet 1y and the pallet 1z. Oxygen concentration in the adjacent portion xy is because significantly higher than the oxygen concentration of the adjacent portion yz, the adjacent portion xy, the gap becomes larger end portions of the pallet 1y palette 1x is worn, the Mokaze point S ₁ It can be judged that

Further, since the oxygen concentration is high at the central portion of the pallet 1x, greater wear at the center of the pallet, it can be determined that the central portion is in the Mokaze point S _2.

  Thus, by measuring and displaying the oxygen concentration over the width Dp of the circulating pallet, it is possible to specify the location of the air leakage in the circulating pallet. Since the air leakage is due to wear of the pallet, it can be said that the pallet having the air leakage portion with a remarkably high oxygen concentration is a pallet with remarkable wear.

  FIG. 6 shows locations where the possibility of air leakage is high in the pallet cross section. As shown in FIG. 6, Sw, Sx, Sy, and Sz are locations where air leakage can occur. That is, when air leakage occurs in the pallet and the adjacent part of the pallet, the oxygen concentration in the adjacent part increases, and air leakage occurs in one or more of Sw, Sx, Sy, and Sz. As a result, the oxygen concentration in the center of the pallet increases.

  Thus, since the location where the air leakage occurs in the pallet is limited, the air leakage location can be easily identified from the position where the oxygen concentration is increased in the oxygen concentration in the pallet width direction displayed for each pallet. This is a feature of the method of the present invention.

  Confirmation of the increase position of the oxygen concentration is easy if the increase of the oxygen concentration is large, and in this case, it means that the pallet is greatly worn. The inventors of the present invention have conceived that it is important to identify and monitor a location where wear is occurring, i.e., a location where air leakage has started, as a location of air leakage, in order to stably continue the sintering operation. The following method was adopted.

(x) When the average oxygen concentration Om (%) of the pallet width direction oxygen concentration and the oxygen concentration Oe (%) at the pallet width direction end satisfy the following formula (1), the pallet end is specified as the air leakage location. .
Oe−Om ≧ Ae (1)
Ae: Constant determined by operational performance

(y) When the average oxygen concentration Om (%) of the oxygen concentration in the width direction of the pallet and the oxygen concentration Oz (%) at a portion other than the end portion in the pallet width direction satisfy the following formula (2), Identify.
Oz−Om ≧ Az (2)
Az: Constant determined by operation results

  FIG. 7 shows the average oxygen concentration Om (%), the oxygen concentration Oe (%) at the end in the pallet width direction, and the oxygen concentration Oz (%) at locations other than the end in the pallet width direction. ) Is schematically shown.

  The average oxygen concentration Om (%) is calculated by excluding the oxygen concentration Oe (%) at the end portion in the pallet width direction and the oxygen concentration Oz (%) at portions other than the end portion in the pallet width direction. Ae and Az are constants determined by the operation results, but different constants may be determined for each pallet. According to operational results, Ae is 0.20 and Az is 0.03. These values are average values and are set as appropriate according to the operating conditions.

  By using the oxygen concentration Oe (%) at the end in the pallet width direction as a reference value, it is possible to automatically specify the location of the air leakage.

However, as shown in FIG. 5, even if the central portion of the pallet 1x is it the Mokaze point S _2, when measuring the next oxygen concentration, as shown in FIG. 7, the central portion of the pallet 1x, the oxygen concentration There may be no increase.

This means that the air leak location S ₂ is not a steady air leak location due to pallet wear but a single air leak location due to non-uniform deposition of the sintering material. Therefore, the oxygen concentration at each lap of the pallet is compared with each pallet, the change in the oxygen concentration accompanying the pallet rotation is confirmed, and a steady air leak location caused by wear and a single air leak location are distinguished.

  And when it can be judged that a wind leak location is a steady wind leak location due to wear, the time of repair or replacement of the pallet is determined based on the oxygen concentration of the wind leak location.

  Next, examples of the present invention will be described. The conditions of the examples are one example of conditions adopted for confirming the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. Is not to be done. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
In the sintering machine (see Fig. 2) where the laser oximeter is placed in the wind box close to the ignition furnace, the laser oximeter is used in the combustion gas sucked by the window box while the pallet goes around. The oxygen concentration was measured and displayed on the display screen of the oxygen concentration display device. FIG. 8 shows the measured oxygen concentration in the pallet width direction.

  Since the oxygen concentration is increased in the adjacent portion between the pallet 30 and the pallet 31, it can be said that the end portion of the pallet 30 and the end portion of the pallet 31 are worn and a large air leak is generated in the adjacent portion. Moreover, since the oxygen concentration is increasing in the adjacent part of the pallet 31 and the pallet 32, it can be said that the end part of the pallet 31 and the end part of the pallet 32 are worn and a large air leak occurs.

  Even in the measurement of the second round, the oxygen concentration was still increased in the adjacent part of pallet 30 and pallet 31 and in the adjacent part of pallet 31 and pallet 32, so pallet 30, pallet 31 and pallet 32 were replaced. It was.

  When the adjacent end portions of the pallet 30, the pallet 31 and the pallet 32 were examined, the adjacent end portions were surely worn out.

  The increase in the oxygen concentration at the center of the pallet 27 disappeared in the second round measurement, so it can be said that this is a single air leak due to non-uniform deposition of the sintering material.

(Example 2)
For the oxygen concentration in the pallet width direction obtained in Example 1, the average oxygen concentration Om (%) of the pallet width direction oxygen concentration was calculated, and Ae = 0.20 and Az = 0.03 were set based on the operation results. Then, according to the following formulas (1 ′) and (2 ′), an attempt was made to identify the location of the air leakage.
Oe−Om ≧ Ae (0.20) (1 ′)
Oz−Om ≧ Az (0.03) (2 ′)

  The results are shown in Table 1. From Table 1, it can be seen that the location of the air leakage can be specified by the above formulas (1 ') and (2').

  As described above, according to the present invention, in the pallet width direction of the sintering machine pallet, it is possible to identify the location of the air leakage, and further estimate the degree of wear of the pallet based on the oxygen concentration of the location of the air leakage. The time for repairing or replacing the pallet can be determined. As a result, during operation of the sintering machine, it is possible to stably secure the air necessary for sintering the sintering raw material and continue the stable sintering operation. Therefore, the present invention has high applicability in the steel industry.

1, 1x, 1y, 1z palette
xy, yz Adjacent part 1a Great bar 1b Side part 2 Wind box 2a Upper side wall 3 Hopper 4 Ignition furnace 5 Sprocket 6 Intake pipe 7 Laser type oxygen concentration meter 8 Oxygen concentration display device 9 Light emitter 10 Light receiver 11 Wheel 12 Rail 12a Mount 13 Outer frame 14 Air seal plate 15 Sintering raw material 16 Electronic device 17 Reading sensor L Laser beam Dp Pallet width S ₁ Air leakage location (adjacent part)
S ₂ air leak location (central part)
Sw, Sx, Sy, Sz Leakage location Om Average oxygen concentration Oe Oxygen concentration at end of pallet width direction Oz Oxygen concentration at locations other than end of pallet width direction

Claims (3)

In the method of measuring the oxygen concentration in the combustion gas sucked in the wind box, the location of the air leak in the sintering machine pallet is specified,
(I) A laser oximeter provided at the top of the window box continuously measures the oxygen concentration in the pallet width direction of the combustion gas immediately below the pallet that circulates and passes over the laser oximeter. Identify the pallet,
(Ii) When displaying the measured oxygen concentration in the pallet width direction for each identified pallet and specifying the location of the air leakage from the increased oxygen concentration position ,
(Ii-1) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oe (%) at the end of the pallet width direction are calculated. When the following formula (1) is satisfied, the end of the pallet is specified as the location of air leakage and / or
(Ii-2) The average oxygen concentration Om (%) of the pallet width direction oxygen concentration displayed for each identified pallet is calculated, and the average oxygen concentration Om (%) and the oxygen concentration Oz of the portion other than the end portion in the pallet width direction are calculated. When (%) satisfies the following formula (2), the location is identified as the location of the air leakage location.
Oe−Om ≧ Ae (1)
Ae: Constant determined by operational performance
Oz−Om ≧ Az (2)
Az: Constant determined by operation results   2. The method for identifying a leaking point of a sintering machine pallet according to claim 1, wherein the pallet is identified by an electronic information device attached to a side of the pallet. The method for identifying a leak location on a sintering machine pallet according to claim 1 or 2 , wherein a time for repair or replacement of the pallet is determined based on a level of oxygen concentration in the leak location.

Images