JP6103430B2 - Rotary kiln axial center correction device and rotary kiln axial center correction method - Google Patents

Description

  The present invention relates to a technique for correcting a shift of an axial center of a rotary kiln.

  The rotary kiln is a long heavy object formed in a cylindrical shape, and has a rotation axis (center axis) along the longitudinal direction. Such a rotary kiln is supported by a plurality of tires arranged in parallel along the axial direction of the kiln shell (fuselage) and a roller that rolls on the tires. The rollers are adjusted and arranged so that the central axis of the kiln shell is straight at the start of operation.

  If the rotary kiln is operated for a long time, uneven wear of the tires and rollers, sinking of the kiln support foundation, thermal deformation of the kiln shell (wearing the refractory brick on the inside of the kiln and affecting the kiln shell due to wear) and thermal deterioration (of the refractory brick) If it is severe, it will cause cracks in the kiln shell. At the initial stage of occurrence of these abnormalities, the central axis of the kiln shell changes or the kiln shell's override (the deformation rate of the fuselage) increases. Preventive maintenance is required to grasp the occurrence of troubles and minimize damage.

  Conventionally, the kiln is stopped about once a year, and periodic inspection and repair are carried out. However, when a large repair item or trouble occurs, the rotary kiln must be stopped each time. For this reason, it is required to suppress loss of production opportunities and repair costs due to production stoppage.

  In view of such a situation, various proposals have been made for inspection and repair of the rotary kiln. For example, Patent Literature 1 discloses a technique for inspecting the state of a refractory brick disposed inside while a rotary kiln is in operation. Specifically, a temperature sensor is provided in and outside the refractory brick layer arranged on the inner surface of the kiln shell, and the temperature of the refractory brick is predicted by wirelessly transmitting this temperature to the outside. .

  Patent Document 2 discloses a technique for automatically correcting a deviation in the center axis height of the kiln shell that has occurred in the rotary kiln while the rotary kiln is in operation. Specifically, the body height is measured at a plurality of positions along the axial direction of the kiln shell, and when the measured value reaches a threshold value that requires correction, the width of the pair of rollers that support the kiln shell is changed. The body height at the support position is adjusted.

  Patent Document 3 discloses a technique for cooling the outer surface of a kiln shell in a heated rotary kiln. The cooling technique disclosed in Patent Document 3 is based on the fact that air is blown toward the outer surface located vertically below the rotation axis of the kiln shell, and mist is mixed into the blown air. When cooling is performed using such a technique, the fog is completely vaporized before reaching the surface of the kiln shell, and the surface of the kiln shell is not wetted. For this reason, it becomes possible to measure the temperature of the kiln shell outer surface by non-contact measuring means such as an infrared thermometer or a radiation thermometer.

JP 2001-4283 A JP 2011-33240 A JP 2010-243145 A

  With the technique disclosed in Patent Document 1, it is possible to know the state change of the refractory brick and to predict the state. However, it is necessary to stop the operation of the rotary kiln to deal with the state change.

  Further, with the technique disclosed in Patent Document 2, it is possible to correct the shift of the central axis in the kiln shell while the rotary kiln is in operation. However, the correction of the shift in Patent Document 2 is only due to wear of a roller or tire that supports the kiln shell, and cannot deal with local deformation caused by local temperature fluctuations in the kiln shell.

  And the technique currently disclosed by patent document 3 is a technique for cooling the outer surface of a kiln shell appropriately in the wide range. For this reason, although it can contribute in order to suppress the thermal deformation and thermal deterioration of a kiln shell, when a change arises in the external shape and axial center of a kiln shell, this cannot be measured and corrected.

  Therefore, in the present invention, when detecting the change of the kiln shell and correcting the shift of the central axis due to the change, the axial center correction device of the rotary kiln and the rotary kiln capable of dealing with the shift due to local deformation accompanying the temperature change An object of the present invention is to provide a method for correcting an axis.

  In order to achieve the above object, an axial center correction apparatus for a rotary kiln according to the present invention comprises a rotary kiln, a measuring means for measuring an axial misalignment of the rotary kiln, a cooling means for cooling the outer surface of the rotary kiln, and the shaft. A control unit that controls the cooling amount of the cooling unit based on the amount of misalignment, and a rotary kiln axial center correction device, the outer surface of the rotary kiln is provided with a plurality of measurement points, the measuring unit, The amount of axial misalignment at the plurality of measurement points is measured, the cooling means is provided so as to be able to cool the plurality of measurement points independently, and the control means includes the axis among the plurality of measurement points. The amount of cooling at the measurement point where the amount of misalignment is equal to or greater than a predetermined threshold value is controlled.

  The axial center correction device for a rotary kiln having the above-described features includes a plurality of support rollers for supporting the outer periphery of the rotary kiln, and the support roller changes the rotary kiln radial direction support position, thereby The control means is configured to change a radial support position of the support roller adjacent to a measurement point of which the axial center deviation amount is equal to or greater than a predetermined threshold among the plurality of measurement points. It may be changed.

  By having such a feature, it is possible to correct the axial position by changing the radial support position in addition to cooling. As a result, more accurate axis correction can be performed.

  A rotary kiln axial center correction method according to the present invention for achieving the above object is a rotary kiln axial center correction method, wherein a plurality of measurement points are provided on an outer surface of the rotary kiln, and the plurality of measurement points are provided. The amount of axial misalignment of the rotary kiln is measured, and the amount of cooling at the measurement point where the amount of axial misalignment is equal to or greater than a predetermined threshold among the plurality of measurement points is independently controlled.

  According to the axial center correction apparatus and method of the rotary kiln having the above-described features, it is possible to cope with a location where a local temperature rise has occurred in the rotary kiln, and to perform axial center correction with high accuracy.

It is a figure which shows the whole structure of the axial center correction | amendment apparatus which concerns on embodiment. It is a figure which shows the one part cross-section structure in the axial center correction | amendment apparatus shown in FIG. It is a figure for demonstrating the mode of adjustment of the radial direction support position of a kiln shell by adjustment of the distance between rollers. It is a figure which shows an example of the relationship between arrangement | positioning of a cooling fan, and arrangement | positioning of a kiln shell. It is a figure which shows a specific example of the fan unit which comprises a cooling means. It is a flow for demonstrating the flow of the axial center correction method which concerns on embodiment. (A) is a figure which shows the example in case the local axial center deviation and the general axial misalignment have arisen, (B) is the example in which the general axial misalignment has arisen (C) is a figure which shows the example in case the axial misalignment has not arisen. It is a figure for demonstrating an example of the temperature measurement result of the kiln shell surface by a radiation thermometer, and the control example based on this.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a rotary kiln axial center correction apparatus and a rotary kiln axial center correction method according to the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, the rotary kiln axial center correction device (hereinafter simply referred to as the axial center correction device 10) according to the embodiment includes a rotary kiln 12 that is symmetric with respect to monitoring, a measuring unit that accompanies this, and cooling. And equipment mainly composed of the control means 38. FIG. 1 is a diagram illustrating an overall configuration of the axial center correction apparatus according to the embodiment, and FIG. 2 is a diagram illustrating a configuration of a cross section of the axial center correction apparatus illustrated in FIG. 1.

  The rotary kiln 12 is configured based on a kiln shell 14 (body) that constitutes a rotary furnace, a kiln support 16 and rollers (support rollers) 18 that support the kiln shell 14, and drive means 20.

  The kiln shell 14 is a metal cylinder formed in a cylindrical shape, and is an outer shell of a heating furnace used for cement production, waste treatment, refining of various raw materials, and the like. The kiln shell 14 constitutes a long heating furnace by connecting the metal cylinders by the length necessary for the heat treatment. On the inner side surface of the kiln shell 14, a refractory brick 14a is disposed. Further, a support frame called a tire 22 is provided on the outer peripheral surface of the kiln shell 14 at predetermined intervals. By adopting a configuration in which a roller 18 described later is brought into rolling contact with the outer periphery of the tire 22, the rotating kiln shell 14 can be supported at a desired height. When the kiln shell 14 is supported by the roller 18, it is not always necessary to interpose the tire 22. However, in order to prevent deformation or wear of the kiln shell 14 due to its own weight, it is desirable to provide the tire 22 on the outer periphery of the kiln shell 14 and support the kiln shell 14 through this. In addition to the tire 22, a girth gear 24 for transmitting a driving force from the driving means 20 is provided on the outer peripheral surface of the kiln shell 14.

  The kiln support 16 is a support member for supporting the kiln shell 14 that is a long and heavy object. A plurality of kiln support bases 16 are provided along the axial direction of the kiln shell 14. By providing the roller 18 on each kiln support 16, the kiln shell 14 can be rotationally supported. For this reason, the arrangement | positioning space | interval of the kiln support stand 16 and the arrangement | positioning space | interval of the tire 22 provided in the outer periphery of the kiln shell 14 shall respond | correspond.

  The roller 18 is a rotating body that is in rolling contact with the lower half of the tire 22, and is provided in pairs on the left and right in FIG. 2 with a perpendicular line a passing through the center of the cross section of the kiln shell 14 as a boundary. Thereby, the kiln shell 14 can be rotationally supported. As shown in FIG. 3, the roller 18 includes a drive unit 26 for changing the distance between the paired rollers 18. Therefore, by operating the drive unit 26 and changing the distance between the paired rollers 18, the support height (radial support position) of the kiln shell 14 is adjusted, and the axial center position A is changed to A '. be able to.

  The kiln shell 14 supported by the plurality of kiln support 16 and the plurality of rollers 18 has an end (discharge side) on the side from which the workpiece is discharged from an end on the side to which the workpiece is introduced (introduction side end). It is arranged so as to have a predetermined inclination angle over the end portion.

  The driving means 20 may be a motor or the like. A pinion gear 28 is connected to the rotating shaft of the driving means 20 directly or via a gear unit (not shown). The driving means 20 is arranged such that the pinion gear 28 meshes with the girth gear 24 provided on the outer peripheral surface of the kiln shell 14. By setting it as such a structure, the kiln shell 14 will rotate according to the drive of the drive means 20. FIG.

  The measuring means is a general term for means for measuring the strain and surface temperature of the kiln shell 14. As a means for measuring the strain of the kiln shell 14, for example, a distance measuring device 30 may be used. Further, as a means for measuring the surface temperature, for example, a radiation thermometer 32 may be used. Of course, other measuring devices may be used as the measuring means.

  The cooling means is means for cooling the kiln shell 14 from the outside. Specifically, a fine fog cooling system 34 or the like may be used. The fine fog cooling system 34 is configured based on a fan unit 34a, a pressure pump unit 34b, and a filter unit 34c. The fan unit 34a is a blower provided with a spray port for ejecting fine mist. In the embodiment, a plurality of fan units 34a are arranged in the axial direction of the kiln shell 14, and the individual fan units 34a can be controlled independently. By setting it as such a structure, it becomes possible to cool the whole region of the kiln shell 14 which is a long thing. The pressurizing pump unit 34b is a unit for pressurizing the cooling water and pumping it to the spray port in the fan unit 34a. The filter unit 34c is a unit for removing impurities contained in the cooling water and preventing clogging of the spray port.

  In the fine mist cooling system 34 having such components, when cooling water is supplied to the filter unit 34c, impurities are removed and sent to the pressure pump unit 34b. The pressurizing pump unit 34b pressurizes the cooling water and pumps it to the fan unit 34a. In the fan unit 34a, the fine mist is ejected from the spray port, and the fine mist is sent out by the blower. The fine mist is vaporized in the air and on the surface of the kiln shell 14 and exhibits a cooling effect.

  As shown in FIGS. 4 and 5, the fan unit 34 a includes a moving unit 34 a 1 that can move on the rail 36 arranged along the axial direction of the kiln shell 14, and changes the blowing direction and angle. It can have a swing function. With the fan unit 34a having such a configuration, it is possible to spray fine mist intensively at a desired position of the kiln shell 14.

  The control means 38 outputs a control signal to the fan unit 34 a of the cooling means and the drive unit 26 of the roller 18 based on the state data of the kiln shell 14 measured by the measurement means such as the radiation thermometer 32 and the distance measuring device 30. It is an element to do.

  In the control means 38, the reference temperature and threshold value for the surface temperature of the kiln shell 14 and the amount of axial misalignment of the kiln shell 14 are determined and recorded in advance. For example, when the kiln shell 14 is in an overcooled state, the amount of coating attached to the inner surface of the refractory brick 14a may increase, or acid condensation may occur between the kiln shell 14 and the refractory brick 14a, leading to low temperature corrosion. In addition, when the cooling is insufficient, the refractory brick 14a may be melted, the high temperature corrosion of the outer surface of the kiln shell 14, or deformation due to thermal expansion may occur. For this reason, by operating the cooling means based on the reference temperature and the allowable value (threshold value) of the temperature, it is possible to suppress the occurrence of troubles based on melting damage and corrosion and misalignment due to deformation. For this reason, there are a high temperature side threshold value and a low temperature side threshold value as the surface temperature threshold value, and the cooling unit performs temperature control with the reference value as a target.

  Also, with respect to the shaft center, by setting a reference value and an allowable deviation amount (threshold value) with respect to the reference value, the position adjustment of the roller 18 by the drive unit 26 is performed so that the shaft center matches the reference value. Is possible.

Next, an axis correction method by the axis correction apparatus having the above configuration will be described with reference to FIG.
First, the distance measurement device 30 measures axial misalignment amounts at a plurality of measurement points along the axial direction of the kiln shell 14 (step 10). Next, or simultaneously with the measurement of the amount of axial misalignment (step 10), the surface temperature at a plurality of measurement points along the axial direction of the kiln shell 14 is measured (step 20).

  Next, the measured value of the amount of misalignment at each measurement point is compared with the threshold value of the amount of misalignment (step 30). As a result of the comparison, when the measured value of the amount of axial misalignment is smaller than the threshold value, the process returns to step 10 to measure the amount of axial misalignment at each measurement point again.

  On the other hand, when the measured value of the axial misalignment amount is equal to or greater than the threshold value, the measured value of the surface temperature at each measurement point is compared with the threshold value of the surface temperature (step 40). When the temperature measurement value at the measurement point where the axial misalignment is equal to or greater than the threshold value is equal to or greater than the high temperature side threshold value, the misalignment may be caused by the deformation of the kiln shell 14 due to heat. For this reason, a command signal is output to the fan unit 34a of the cooling means in order to cool the corresponding measurement points intensively. The fan unit 34a that has received the command signal controls the spray amount, the blowing amount, the blowing angle, the blowing position, and the like so as to intensively cool the measurement points to be cooled (step 50). After central cooling for a predetermined time or together with central cooling, the amount of axial misalignment in step 10 is measured, and so-called feedback control is performed.

  When the surface temperature is compared (step 40), if the measured value is lower than the high temperature side threshold value, the cause of the axial misalignment may be due to wear of the tire 22 or roller 18 or settling of the kiln support 16. Or, there is a high possibility of plastic deformation of the kiln shell 14 not caused by thermal expansion or the like. In this case, a command signal is output to the drive unit 26 of the roller 18 located in the vicinity of the measurement position where the shaft misalignment occurs, and the width of the pair of rollers 18 is adjusted, so that the shaft center of the corresponding portion is adjusted. It approaches the reference value (step 60).

  After correcting the center of the axis by adjusting the position of the roller 18, the process returns to the step of measuring the amount of center misalignment at each measurement point (step 10). In the temperature comparison step (step 40), when the measured value is equal to or lower than the low temperature side threshold value, a command signal is sent to the fan unit 34a that cools the corresponding portion so as to reduce the cooling effect at the corresponding measurement point. Is output.

  According to such an axial center correction method, with respect to local deformation (axial misalignment) accompanying local temperature fluctuations of the kiln shell 14, the central cooling location indicated by the broken line in FIG. Correction is performed by individually cooling by means). When the axial misalignment due to the local deformation is eliminated by the concentrated cooling, the axial misalignment that cannot be corrected only by the cooling, or the axial misalignment not caused by the temperature fluctuation is shown in FIGS. 7), by adjusting the support width of the roller 18 that is in rolling contact with the tire 22 located at the height adjustment position indicated by the broken line, the shaft center can be corrected to approach a straight line as shown in FIG. it can. Specifically, for example, as illustrated in FIG. 8, it is assumed that the temperature distribution along the axial direction of the kiln shell 14 is measured. In this case, among the measurement points a to s, when the amount of axial misalignment in the vicinity of the measurement points c and d is large and a local high temperature is recognized, the cooling rate in the vicinity of the measurement points c and d is improved. Then, a command signal is given to the fan unit 34a. Then, among the tires 22 indicated by the arrows A to C, the mechanical distance is adjusted by adjusting the interval between the rollers 18 that support the tire 22 corresponding to the arrow A in the vicinity of the measurement points c and d where the axial misalignment occurs. The operation of correcting the distortion of the kiln shell 14 is performed. In contrast to the local high temperature part, the vicinity of the measurement point p is locally low. In such a case, a command signal is given to the fan unit 34a so as to reduce the cooling rate in the vicinity of the measurement point p.

  Thus, according to the present invention, correction corresponding to both local deformation and general deformation can be performed. Therefore, it is possible to correct the misalignment with higher accuracy than in the past.

DESCRIPTION OF SYMBOLS 10 ......... Axis center correction | amendment apparatus, 12 ......... Rotary kiln, 14 ......... Kiln shell, 14a ......... Fire brick, 16 ......... Kiln support stand, 18 ......... Roller, 20 ......... Drive means, 22 ......... Tire, 24 ...... Girth gear, 26 ......... Drive unit, 28 ......... Pinion gear, 30 ......... Distance measuring device, 32 ......... Radiation thermometer, 34 ......... Fine mist cooling system, 34a ......... fan unit, 34a1 ......... moving means, 34b ......... pressure pump unit, 34c ......... filter unit, 36 ......... rail, 38 ......... control means.

Claims (3)

With rotary kiln,
Measuring means for measuring the amount of axial misalignment of the rotary kiln;
Cooling means for cooling the outer surface of the rotary kiln;
Control means for controlling the cooling amount of the cooling means based on the amount of axial misalignment;
A rotary kiln axial center correction device having
A plurality of measurement points are provided on the outer surface of the rotary kiln,
The measuring means measures an axial misalignment amount at the plurality of measurement points,
The cooling means is provided so that the plurality of measurement points can be cooled independently,
The said control means controls the amount of cooling in the measurement point from which the said axial center deviation | shift amount became more than a predetermined threshold among these measurement points, The axial center correction | amendment apparatus of the rotary kiln characterized by the above-mentioned. In the axial center correction apparatus of the rotary kiln according to claim 1,
A plurality of support rollers for supporting the outer periphery of the rotary kiln;
The support roller is provided so that the axial center of the rotary kiln can be changed by changing the support position in the radial direction of the rotary kiln,
The control means changes the radial support position of the support roller adjacent to the measurement point at which the amount of axial misalignment is equal to or greater than a predetermined threshold among the plurality of measurement points. Heart correction device. A method for correcting the axial center of a rotary kiln,
A plurality of measurement points are provided on the outer surface of the rotary kiln,
Measuring the amount of axial misalignment of the rotary kiln at the plurality of measurement points;
A method of correcting a shaft center of a rotary kiln, comprising: independently controlling a cooling amount at a measurement point at which the amount of axial misalignment exceeds a predetermined threshold among the plurality of measurement points.

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