JP5573482B2 - How to detect the location of air leakage in the sintering machine pallet - Google Patents

Description

  The present invention relates to a method for accurately detecting 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 materials.

  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 (in the direction of the arrow in the drawing) on the pallet 1 and the pallet 1 on the iron ore and charcoal. A hopper 3 for charging a sintered raw material such as a material in layers, an ignition furnace 4 for igniting the sintered raw material deposited on the pallet, and air under the pallet 1 through the sintered layer and the raw material layer It consists of a windbox 2 that 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 and affects 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.

  In addition, air 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, thereby generating air leakage.

  The air leakage generated in the sintering machine adversely affects the progress of sintering and leads to a decrease in productivity. Therefore, it is important to detect the degree of air leakage accurately 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 it is a measurement of oxygen concentration in a wide range, it is difficult to specify the air leakage at a specific location of the pallet.

  In order to perform sintering properly on a rotating pallet, a certain amount of air necessary for the sintering reaction is required. However, if air leakage occurs in the sintering machine, the necessary amount of air is secured. 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 survey results, 20-50% of the air leakage is due to wear of the pallet.

  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

  The present invention is a laser-type oximeter placed at the top of the window box, which measures the oxygen concentration in the sintering gas sucked through the sintered layer and raw material layer accurately under the pallet. An object of the present invention is to provide a detection method that solves the problem by detecting an air leak location in a moving pallet and taking measures against the air leak.

  The present inventors diligently studied a method for detecting an air leak location in a pallet. As a result, it was found that if the oxygen concentration in the pallet traveling direction is displayed for each pallet and the position where the oxygen concentration changes is specified, the location of the air leakage can be detected.

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

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

(1) In a detection method for detecting an air leak location in a sintering machine pallet based on the oxygen concentration in the combustion gas sucked by the wind box,
(I) A pallet that passes above the laser oximeter while measuring the oxygen concentration in the combustion gas immediately below the rotating pallet with a laser oximeter in the pallet width direction provided at the top of the wind box Identify and
(Ii-1) The measured oxygen concentration is displayed for each identified pallet continuously in the order of the identified pallets,
(Ii-2) From the position where the oxygen concentration increases , it is detected that the location of the air leakage in the pallet is one or both of the adjacent part of the pallet and the central part of the pallet ,
(Iii) A method for detecting an air leakage location in a sintering machine pallet, wherein the timing of repair or replacement of the pallet is determined based on the oxygen concentration of the air leakage location.

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

  According to the present invention, it is possible to accurately detect the location of the air leak in the sintering machine pallet, and further, based on the detection result, accurately estimate the degree of wear of the pallet and repair or replace the pallet. Can be accurately determined. As a result, air necessary for sintering of the sintering raw material can be stably secured during operation of the sintering machine.

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 a pallet cross section. It is a figure which shows the oxygen concentration for every pallet measured in the Example ((a): Before countermeasure against wind leak, (b): After countermeasure against wind leak).

  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 an upper surface aspect of the sintering machine (the raw material supply hopper 3 and the ignition furnace 4 are not shown), and FIG. 2B shows a side aspect of the sintering machine.

  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-type oxygen concentration meter 7 is disposed in the wind box 2 close to the ignition furnace 4, but in the present invention, it is only necessary to measure the oxygen concentration capable of detecting a leak location. The arrangement 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 can be measured and the location of the air leak can be detected, but two or more may be arranged in order to improve the detection reliability.

  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 rotates.

  The lower end portion of the pallet 1 is attached to the upper end surface of the upper side wall 2a of the wind box 2 as the pallet 1 rotates, and slides on the air seal plate 14 while maintaining airtightness.

  On the upper side wall 2 a of the wind box 2, a light emitter 9 that emits laser light L and a light receiver 10 that receives the laser light L that has traversed the wind box 2 are disposed to constitute a laser oximeter 7. .

  A laser oxygen concentration meter 7 measures the oxygen concentration in the sintering gas sucked by the window box 2 immediately below 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 oximeter 7 is transmitted to the oxygen concentration display device 8 (see FIG. 2A), and the transition is displayed on the display 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, it is possible to use a barcode (one-dimensional code) and various two-dimensional codes (commercially available various codes such as a QR code and a CP code). 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 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. In the figure, # 01 to # 10 are pallet identification information. The following can be understood from FIG.

(A) Transition of oxygen concentration is different for each pallet.
(B) The oxygen concentration is high in the adjacent part of the pallet.
(C) The oxygen concentration in the adjacent part of the pallet is different in the adjacent part.
(D) There is a pallet with a high oxygen concentration in the center.

  Although the pallet is worn by the sintering operation, there is a difference in the degree of wear between the pallets, and as a result, a difference occurs in the degree of air leakage, and it is estimated that the distribution of oxygen concentration varies from pallet to pallet.

  It is inevitable that a certain amount of air leakage will occur in the adjacent part of the pallet and the oxygen concentration will be high, but in the adjacent part of the pallet where the oxygen concentration is extremely high, due to wear of the pallet, the gap will expand and a large air leakage will occur. I guess that. In a pallet with a high oxygen concentration in the center, it is presumed that air leakage occurs in 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 location where the air leaks.

Air leakage occurs in the adjacent part xy between the pallet 1x and the pallet 1y and in the adjacent part yz between the pallet 1y and the pallet 1z, but if the oxygen concentration in the adjacent part xy is significantly higher than the oxygen concentration in the adjacent part yz, in part xy, pallets 1x and pallet 1y is, the gap is increased by increasing wear at the edge, it can be said that has a Mokaze point S _1.

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

  Thus, by measuring the oxygen concentration over the length Dp of the pallet, it is possible to detect the location of the air leak in the rotating pallet. Leakage is largely due to wear of the pallet, so a pallet with a leak point where the oxygen concentration is extremely high is a pallet with significant wear.

  Here, FIG. 6 shows a portion where the possibility of air leakage is high in the pallet cross section. As shown in the figure, Sw, Sx, Sy, and Sz are locations where air leakage can occur. When the oxygen concentration is high at the adjacent or central portion of the pallet, wear progresses, and it can be said that air leakage occurs at one or more of Sw, Sx, Sy, and Sz. Depending on the height, it is possible to accurately determine the time for repairing or replacing the pallet.

  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)
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. The transition of the oxygen concentration was displayed on the display screen of the oxygen concentration display device based on the pallet identification information.

  FIG. 7 also shows the oxygen concentration (curve (a)) for each pallet before countermeasures against air leakage and the oxygen concentration (curve (b)) for each pallets after countermeasures against air leakage. From the increase in oxygen concentration, it is possible to immediately detect the location of the air leak in the connected pallets.

  Pallets # 5, # 6, and # 7 were worn out at both ends, so they were immediately replaced with new pallets. Pallet # 2 was worn at the center, but it was judged that the degree of wear was small from the value of oxygen concentration, and it was repaired and used. As a result, it can be seen from the oxygen concentration (curve (b)) after the implementation of measures against air leakage that the oxygen concentration was lowered.

  As described above, according to the present invention, it is possible to accurately detect the location of the air leak in the sintering machine pallet, and further, based on the detection result, accurately estimate the degree of wear of the pallet, The time for repair or replacement can be determined accurately. As a result, air necessary for sintering of the sintering raw material can be stably secured during operation of the sintering machine. Therefore, according to the present invention, a homogeneous sintered ore can be produced with high productivity. Therefore, the present invention has high applicability in the steel industry.

DESCRIPTION OF SYMBOLS 1, 1x, 1y, 1z Pallet 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 Mounting frame 13 Outer frame 14 Air seal plate 15 Sintering raw material 16 Electronic device 17 Reading sensor 18 Adjacent part L Laser beam Dp Pallet length S ₁ Air leakage location (adjacent part)
S ₂ air leak location (central part)
Sw, Sx, Sy, Sz

Claims (2)

In the detection method of detecting the air leak location in the sintering machine pallet based on the oxygen concentration in the combustion gas sucked in the wind box,
(I) A pallet that passes above the laser oximeter while measuring the oxygen concentration in the combustion gas immediately below the rotating pallet with a laser oximeter in the pallet width direction provided at the top of the wind box Identify and
(Ii-1) The measured oxygen concentration is displayed for each identified pallet continuously in the order of the identified pallets,
(Ii-2) From the position where the oxygen concentration increases , it is detected that the location of the air leakage in the pallet is one or both of the adjacent part of the pallet and the central part of the pallet ,
(Iii) A method for detecting an air leakage location in a sintering machine pallet, wherein the timing of repair or replacement of the pallet is determined based on the oxygen concentration of the air leakage location.   2. The method for detecting a leak location in a sintering machine pallet according to claim 1, wherein the pallet is identified by attaching an electronic device incorporating pallet identification information to a side portion of the pallet. 3.

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