JP5298629B2 - Air leakage detection device for sintering machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wind leakage detector of a sintering machine which can detect the wind leakage caused by a pallet endlessly rotating on the sintering machine stably and precisely for a long period of time. <P>SOLUTION: At the fixed position in a longitudinal direction of the line in the sintering machine 5 (moving direction of the pallet 1), a light emitter 9 for emitting laser beam in a laser type oxygen content meter 17 and a light receiver 10 for detecting the laser beam are disposed to be opposed to the width direction of the pallet 1 on the uppermost part of a wind box 2 positioned at just below the pallet 1. The light emitter 9 and the light receiver 10 are disposed so that the beam axis of the laser beamis is in parallel to the direction for connecting these machines, is horizontal to the ground and parallel to the bottom surface of the pallet 1 and becomes the right angle to the longitudinal direction of the line in the sintering machine 5. When the light emitter 9 and the light receiver 10 are installed in the wind box 2, a purge tube 13 is provided, and the gas containing no oxygen is blown into the purge tube 13. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an air leakage prevention device for a sintering machine, and more specifically, a raw material is placed on a pallet to form a packed layer of the raw material, and the connected pallet is sintered while rotating endlessly on the sintering machine casing. For a sintering machine that continuously produces ore, this technique is suitable for detecting air leakage caused by pallets.

  In the blast furnace steel industry, as shown in FIG. 5, the sintering machine 5 includes a series of pallets P that can be moved in the longitudinal direction by connecting a large number of pallets 1 in the longitudinal direction, and below the series of pallets P. And an air intake means composed of a plurality of window boxes 2 fixed in parallel. As shown in the perspective view shown in FIG. 6, each pallet 1 is provided with wheels 11 on the outer side of the sidewalls 8 arranged on both sides with the great bars 7 arranged on the bottom surface with the great bars 7 arranged on the bottom surface. As shown in FIG. 5 (b), the series of pallets P are connected at the front end and the rear end, and have a structure in which the inside of the casing 19 of the sintering machine 5 rotates endlessly. 5A is a plan view of the sintering machine 5, and FIG. 5B is a side view. Each wind box 2 is depressurized by a blower via an intake pipe 16. Then, during the rotation of the series of pallets P, a sintered raw material layer containing coke powder is supplied to each pallet 1 from the raw material supply hopper 3 and loaded. The surface of the sintered raw material layer is ignited by the ignition furnace 4 and simultaneously sucked through the wind box 2. By being sucked in this way, the combustion zone advances downward from the surface of the sintering raw material layer 20 (FIG. 7), and the sintered ore is continuously produced. FIG. 7 shows a cross-sectional view of the pallet 1 and the window box 2, that is, the sintering machine 5 as seen from the longitudinal direction of the sintering machine 5. The series of pallets P move on the two rails 12 fixedly provided on both sides in the casing 19 of the sintering machine 5 as the wheels 11 provided on each pallet 1 roll.

  By the way, this sintering machine 5 has an advantage that it can continuously produce sintered ore, but breakage of the great bar 7 provided on the bottom surface of the pallet 1 and displacement of the connecting portion of the sidewall 8 between adjacent pallets. Furthermore, there is a disadvantage that it is difficult to make a sealed structure due to wear of the pallet seal bar 6 (see FIG. 7). That is, a gap is generated there, and a large amount of useless air (air leakage) that does not contribute to sintering and does not pass through the sintering raw material layer 20 may flow into the wind box 2. If there is a lot of this air leakage, the wasteful power will be consumed for the production of sintered ore, which will be a large economic loss.

  Therefore, conventionally, various methods for detecting the air leakage have been considered. These are roughly classified into two methods, one is a method for measuring the oxygen concentration in the exhaust gas, and the other is a method for measuring the flow rate (flow velocity) of the exhaust gas.

  The air leakage detection method for a sintering machine disclosed in Patent Document 1 belongs to a method for measuring the oxygen concentration in exhaust gas, and is a method for detecting air leakage due to wear of the pallet seal bar 6. Measure the oxygen concentration in the exhaust gas at the position directly below the center in the width direction of the pallet 1 and the position immediately below the end in the width direction of the pallet 1 at the fixed position in the longitudinal direction of the sintering machine. By comparison, the wear state of the seal bar 6 for each pallet 1 is determined.

  Specifically, at a fixed position in the longitudinal direction of the sintering machine 5, the exhaust gas suction pipes are inserted by removing the flanges at the tips of the guide tubes provided in the respective wind boxes 2. The exhaust gas in the wind box 2 is sucked in the end of the pallet width direction and is led to an oxygen analyzer arranged outside the wind box 2 by a hose, and the oxygen concentration of the exhaust gas is measured. Then, the exhaust gas suction pipe is moved in the wind box 2 in the width direction of the pallet 1 to measure the oxygen concentration at the center portion in the width direction of the pallet 1 and compare the measured values to determine the state of the air leakage. .

  The method for preventing air leakage of a sintering machine disclosed in Patent Document 2 belongs to a method for measuring the flow rate in exhaust gas, and is a method of measuring the firing of a plurality of wind boxes 2 fixed in the longitudinal direction of the sintering machine. In order to prevent air leakage from the gap between the upper end wall surface of the wind box 2 in the longitudinal direction of the binding machine and the bottom surface of the pallet 1 loaded with raw materials and traveling on the wind box 2 In addition, the amount of air leakage from the gap is continuously measured by a plurality of wind speed measuring sensors such as a plurality of hot-wire anemometers arranged in parallel in the width direction of the pallet 1. Then, the elastic plate band is pressed against the bottom surface of the pallet 1 along the front wall and the rear wall of the wind box 2 so that the amount of air leakage is always below the target value.

  On the other hand, Non-Patent Document 1 describes a technique in which a laser oximeter is applied to detect an oxygen concentration in a gasification melting facility. In Non-Patent Document 1, compared with the zirconia type that has been generally used as an oxygen concentration measuring apparatus conventionally, (1) the response speed is fast (about 2 seconds), and (2) measurement is possible even under high temperature and high dust. (3) Since the average density of the duct through which the laser passes is higher, the measured value is more reliable than the suction type that sucks at a point. (4) Maintenance costs because there are no moving parts and no reagents are used. It is pointed out that it does not take.

JP-A 61-195929 Japanese Patent Laid-Open No. 11-264027 Kurimoto Technical Report NO. 56, 17-18

  However, in the “sintering air leakage detection method” described in Patent Document 1, the response delay due to the time required for gas replacement inherent in the gas sampling system composed of the exhaust gas suction pipe and the hose, and the analyzer body This has the disadvantage of delaying the response of oxygen concentration measurement. In general, the pallet moves at a speed of about 2.5 m / min, and the above-mentioned response delay is a big problem in both the temporal resolution of the oxygen concentration measurement value and the resolution of the measurement accuracy. In addition, the exhaust gas of the sintering machine has a high concentration of dust and moisture, and maintenance for maintaining the gas sampling system normally without being clogged with dust or the like is not easy.

  In addition, in the “method for preventing air leakage of a sintering machine” described in Patent Document 2, it is necessary to provide a large number of hot-wire anemometers in the pallet width direction, but in a large-scale sintering machine, the length in the pallet width direction is about 5 m. Yes, for example, when six anemometers, which are the minimum values described in Patent Document 2, are provided, it is necessary to detect a leak in a pallet width of about 0.8 m with one anemometer. Obviously, it is impossible to measure in this range with sufficient accuracy due to the measurement principle of hot-wire detection. Therefore, an enormous number of anemometers are required to improve the pallet width direction position resolution. In addition, as mentioned above, the exhaust gas of the sintering machine has a high concentration of dust and moisture, and even if the recommended hot-wire anemometer is used, maintenance to maintain many anemometers normally There was a problem that was not easy.

  In view of the above problems of the conventional air leak detection method of a sintering machine, the present invention provides long-term stable air leakage caused by the pallet itself for a series of pallets rotating endlessly on the sintering machine housing. It is an object of the present invention to provide an air leakage detection device and method for a sintering machine that can be accurately detected.

  The gist of the present invention is as described below.

The air leakage detection device for a sintering machine according to the present invention includes a series of endless pallets in which a plurality of pallets that can be moved by loading a sintering raw material are connected in the moving direction, and the leading end and the trailing end are connected. A plurality of wind boxes fixed to the housing and disposed under the series of pallets; and an intake pipe connected to the lower end of each of the plurality of wind boxes for exhausting the gas in the wind box; In the air leak detection device for a sintering machine, the light emitter and the light receiver are respectively opposed in parallel to the width direction of the pallet on the upper portion of the wall facing the direction perpendicular to the longitudinal direction of the sintering machine of the window box. One or a plurality of laser oximeters that emit laser light from the light emitter and receive light by the light receiver to measure the oxygen concentration in the optical path, and the laser oximeter Measured wei Based on the value of the oxygen concentration in de box, and a data processing device for detecting the presence and magnitude of the leakage air for each of the series of pallets, the exit opening and the light receiver of the light emitting device of the laser oximeter A sealing glass window through which the laser beam can be transmitted is disposed at the light receiving port, and a purge gas is disposed on the outer side in parallel with the optical path of the laser beam to cover the optical path and allow purge gas to flow inside. characterized in that it have a pipe.

Further, in the above-described air leak detection device for a sintering machine , the laser oximeter has a tip of a purge pipe on the light emitter side and a tip of a purge pipe on the light receiver side, It may protrude toward the inside of the window box, and the oxygen concentration in a predetermined range in the width direction in the window box may be measured.

  As described above, according to the air leakage detection device of the present invention, the air leakage from the breakage of the great bar mounted on the bottom surface of the pallet, the air leakage from the connecting portion of the sidewall between adjacent pallets, and the pallet seal bar It is possible to accurately detect the air leak due to the wear of the pallet, and it is possible to reliably identify the pallet that is leaking air. Therefore, by replacing and repairing the specified pallet having air leakage, it is possible to significantly and stably reduce the air leakage as compared with the conventional pallet. As a result, not only the power consumption of the sintered main exhaust fan can be reduced, but also the production of sintered ore can be increased due to the increase in the amount of air normally sucked through the sintering pallet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<First Embodiment>
Embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a sintering machine 5 in which the air leakage detection device according to the present invention is used, in which (a) is a plan view and (b) is a side view. As shown in FIG. 1, the sintering machine 5 is provided with a plurality of pallets 1 connected in the longitudinal direction, a series of pallets P movable in the longitudinal direction, and fixed below the series of pallets P. Air intake means including a plurality of wind boxes 2. As shown in FIG. 6, each pallet 1 is provided with wheels 11 on the outside of sidewalls 8 arranged on both sides with the great bars 7 arranged on the bottom surface with the great bars 7 arranged on the bottom surface. As shown in FIG.1 (b), the front-end | tip and rear-end of a series of pallets P are connected, and the inside of the housing | casing 19 of the sintering machine 5 rotates endlessly. Each window box 2 is depressurized by a blower (not shown) through an intake pipe 16. During the rotation of the series of pallets P, the sinter raw material layer 20 containing the coke powder is supplied to the pallets 1 from the raw material supply hopper 3 and loaded. The surface of the sintered raw material layer 20 is ignited by the ignition furnace 4 and sucked through the wind box 2. FIG. 2 shows a cross-sectional view of the sintering machine 5 as seen from the longitudinal direction. The series of pallets P move on the two rails 12 fixedly provided on both sides in the casing 19 of the sintering machine 5 as the wheels 11 provided on each pallet 1 roll.

  In the present invention, as shown in FIG. 2, the width direction of the pallet 1 is placed on the uppermost side wall of the wind box 2 located immediately below the pallet 1 in the longitudinal direction of the line of the sintering machine 5 (moving direction of the pallet 1). The light emitter 9 that emits laser light and the light receiver 10 that detects the laser light of the laser oximeter 17 are installed. The reason for installing the windbox 2 on the upper side wall is that the airflow flowing into the windbox 2 from the pallet 1 is diffused as it is drawn downward toward the intake pipe 16, and the location of the airflow is specified. This is because it is preferable to be as close to the pallet 1 as possible. At this time, in order to make the air leak detection sensitivity in the width direction of the pallet 1 uniform, the optical axis of the laser beam parallel to the direction connecting the light emitter 9 and the light receiver 10 is parallel to the ground and parallel to the bottom surface of the pallet 1. To be. Further, in order to easily identify the leaking pallet 1, the light emitter 9 and the light receiver 10 are installed so that the optical axis is perpendicular to the line longitudinal direction of the sintering machine 5. Further, a data processing device 18 such as a personal computer is connected to the laser oximeter 17 (FIG. 1A).

  In this embodiment, as shown in FIG. 2 and FIG. 3 (partially enlarged view), through holes are provided at opposing positions of the base 12a of the rail 12 on both sides on which the wheels 11 of the pallet 1 roll and the side wall 2a of the wind box 2. A purge pipe 13 is passed through each of the through holes, and a light emitter 9 is connected to the end of one purge pipe 13 and a light receiver 10 is connected to the end of the other purge pipe 13 via a flange 14. A protective sealing glass window 15 is provided in each of the light exits of the light emitter 9 and the light receiver 10 of the light receiver 10. For the purpose of preventing the sealing glass window 15 from becoming dirty and preventing the purge pipe 13 from being clogged with dust in the exhaust gas, the inside of the wind box 2 is inserted into the purge pipe 13 from the sealing glass window 15 of the light emitter 9 and the light receiver 10. Then, nitrogen gas is blown as a purge gas. However, the flow rate of nitrogen gas is such that the composition of the exhaust gas is not significantly affected by the nitrogen gas that is blown. The purge gas may be a gas other than nitrogen gas that does not interfere with the oxygen concentration measurement.

  At normal time without air leakage, the oxygen concentration in the exhaust gas in each wind box 2 of the sintering machine 5 is close to 17 to 20% on the feed side A in the longitudinal direction of the sintering machine 5 shown in FIG. It gradually decreases to 10% or less as it reaches the middle part, and rises again on the ore-exit side B, becoming nearly 21%. This is because the calcination reaction is still only near the surface (upper side) of the combustion raw material layer 20 on the supply side A, so that unreacted oxygen reaches the windbox 2 as it is, and the calcination reaction becomes full-scale in the middle part. Unreacted oxygen decreases, and it is considered that the oxygen concentration rises again because the calcination reaction itself is completed on the exhaust side B.

  Therefore, since the air leakage is air and the oxygen concentration is 21%, the position where the difference between the normal state where there is no air leakage due to deterioration of the pallet 1 and the abnormal state where there is air leakage tends to occur, that is, the oxygen concentration is low and stable. It is preferable to install a laser oximeter in the middle part of the sintering machine 5 in the longitudinal direction. However, if the installation space cannot be installed in the middle due to the installation space, it is possible to detect the air leakage by selecting and installing a place where the oxygen concentration is high and stable as much as possible.

  Furthermore, since the ambient temperature of the wind box 2 increases as it approaches the discharge side B, the heat supply and maintenance properties of the light emitter 9 and the light receiver 10 of the laser oximeter are considered as the supply side A among the intermediate portions. It is good to install in the one near. Further, the dust in the exhaust gas in the wind box 2 is also less on the supply side A, and the influence of the attenuation of the laser beam due to the dust and the clogging of the purge pipe 13 are less advantageous.

  As an example, in the above embodiment, a laser oximeter is installed in the seventh wind box 2 from the supply side A among all 26 wind boxes 2. The oxygen concentration in the normal operation state at this installation position is around 7%, but this value rose to 8-9% when passing through the pallet 1 with air leakage. Therefore, in this case, an alarm is output when the oxygen concentration is 8% or more, and the air leak is notified to the operation operator.

  The diameter of the laser beam of the laser oximeter used here is sufficiently small, about 20 mmΦ, and has a response of about 3 seconds. By attaching a position measuring device in the line longitudinal direction of each pallet 1 to the sintering machine 5 and measuring the position of each pallet 1 and using the measured oxygen concentration value obtained with a laser-type oximeter, In addition to the specification of the pallet 1 that is leaking air, it is possible to specify the position of the leakage in the traveling direction in the specified pallet 1. In that case, the data of the pallet position and the oxygen concentration data are taken into the data processing device 18 configured by using a personal computer or the like through the I / O board, and the air leakage is detected from the abnormal oxygen concentration. You may make it display on a computer display with the name of the pallet in which the air leak has occurred.

  In the above description, the configuration using one laser-type oximeter has been described. However, it is obvious that the air leakage detection device may be configured using a plurality of units.

<Second Embodiment>
In the first embodiment, since the laser light from the laser oximeter propagates through the exhaust gas in the entire width direction of the pallet 1 and measures the average concentration, the position of the air leakage in the width direction of the pallet 1 cannot be specified. . Therefore, it is not possible to distinguish between a leak due to wear of the pallet seal bar 6 and a leak due to breakage of the great bar 7. However, in order to repair the leaking pallet 1, generally, it must be performed off-line of the sintering machine 5, so when it is sufficient to determine which pallet 1 is leaking at least, The air leakage detection method of the first embodiment is sufficient.

  On the other hand, when it is necessary to specify the position of the air leakage in the width direction of the pallet 1, the tip of the purge pipe 13 is extended into the wind box 2 and extended so as to protrude as shown in FIG. As a result, the range in which the purge pipe 13 is disposed is masked, so that only the range not masked by the purge pipe 13, that is, the oxygen concentration in a predetermined range can be measured. For example, if the tips of the purge pipes 13 of the light emitter 9 and the light receiver 10 of the laser oximeter 17 are extended by 1 m into the wind box 2, for example, if the width of the pallet 1 is 5 m, the central portion 3 m It is possible to detect the leakage of air.

  This method has a merit that the measurement sensitivity is improved because the range in the width direction of the pallet 1 that can be measured is reduced, and therefore even a small amount of air leakage can be detected early. Moreover, it is advantageous for measurement in a place where there is a lot of dust and the attenuation of laser light is large. In this case, the width direction of the pallet 1 may be divided into a plurality of sections, and each section may be shared by a plurality of laser oximeters to detect the concentration.

  In the above, the air leakage detection device of the present invention has been described in detail as an example of detecting the air leakage caused by the pallet in the sintering process, which is the upper process of the steel industry, but the air leakage detection device of the present invention is not limited to the steel industry. Obviously, it can be applied to processes and similar processes in other industries.

The sintering machine provided with the air leak detection apparatus of this invention is shown, (a) is a top view, (b) is a side view. It is sectional drawing seen from the CC line of FIG. FIG. 3 is an enlarged view of the laser oximeter portion of FIG. 2. It is sectional drawing which shows embodiment different from FIG. A general sintering machine is shown, (a) is a plan view and (b) is a side view. It is a perspective view of a pallet. It is sectional drawing seen from the DD line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pallet 2 Wind box 3 Raw material supply hopper 4 Ignition furnace 5 Sintering machine 6 Pallet seal bar 7 Great bar 8 Side wall 9 Light emitter 10 Light receiver 11 Wheel 12 Rail 13 Purge pipe 14 Flange 15 Seal glass window 16 Intake pipe 17 Laser Type oxygen concentration meter 18 Data processing device 19 Case 20 Sintering raw material layer

Claims (2)

A plurality of movable pallets loaded with sintering raw materials are connected in the moving direction, a series of endless pallets in which the front end and rear end are connected, and the series of pallets fixed to the housing In the air leakage detection device for a sintering machine, comprising a plurality of window boxes disposed below, and an intake pipe connected to the lower ends of each of the plurality of window boxes to exhaust the gas in the window box,
A light emitter and a light receiver are respectively disposed in parallel with the width direction of the pallet on the upper portion of the wall facing the direction perpendicular to the longitudinal direction of the sintering machine of the wind box, and from the light emitter One or more laser-type oximeters that emit laser light, receive the light with the light receiver, and measure the oxygen concentration in the optical path;
Based on the value of the oxygen concentration in the wind box measured with the laser oximeter, the data processing device for detecting the presence and size of air leakage for each of the series of pallets ,
A sealing glass window through which the laser beam can be transmitted is disposed at the light emission port of the laser oximeter and the light receiving port of the light receiver, and further on the outer side in parallel with the optical path of the laser light. Mokaze detecting apparatus of the sintering machine, characterized by have a purge pipe for flowing a purge gas therein with arranged to cover the optical path. In the laser oximeter, the tip of the purge pipe on the light emitter side and the tip of the purge pipe on the light receiver side protrude toward the inside of the wind box, and a predetermined range in the width direction in the wind box The oxygen leakage concentration of the sintering machine according to claim 1, wherein the oxygen concentration is measured .

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