DE102011108747A1 - Method and controller for setting the burn-through point in a sintering machine - Google Patents

Abstract

For setting the burn-through point (D) in a sintering machine (1), in which the material to be sintered on a conveyor line (3) abandoned, ignited and transported in the conveying direction (F) Windboxes (6) over to a material discharge (5) is measured at at least three in the conveying direction (6) successively on the conveyor line (3) arranged measuring points (10) the temperature and the conveying speed of the sintering machine (1) depending on the position of the maximum measured temperature (D (i)) to the Position of the selected Durchbrennpunkts (D) set on the conveyor line. The course of the temperature of three consecutively arranged measuring points (10) is compared, wherein a maximum of the temperature is assumed when in the conveying direction (F) first and third measuring point (10) have a lower temperature value than the second measuring point (10), and wherein no maximum of the temperature is assumed if all measuring points (10) form an ascending series of temperature values. With an assumed maximum of the temperature, the conveying speed is set as a function of a deviation between the position of the measuring point with the maximum temperature value (D (i)) and the position of the selected burn-through point (D), while if no maximum temperature is assumed, the conveying speed is set by one predetermined value is reduced.

Description

The invention relates to a method and a regulator for setting the burn-through point in a sintering machine. In the sintering machine, the material to be sintered, for example, containing ores, is fed onto a conveyor line, for example a traveling grate or grate carriage, ignited and transported past windboxes, which are arranged in the conveying direction and driven in the suction direction, until they are shed. During transport on the sintering machine, the material to be sintered is burned to a sinter cake and at the end of the sintering machine in the material discharge, eg. By breaking, ejected and fed to subsequent processes. In the method for setting the burn-through point, the temperature determined by the temperature of the material to be sintered is measured at at least three measuring points arranged one after the other in the conveying direction and the conveying speed of the sintering machine is dependent on the position of a maximum measured temperature to the position of a previously selected burn-through point set on the conveyor line.

In sintering mostly granular or powdery substances are connected by heating with each other. The heating takes place by igniting the material surface on the sintering machine following the material feed. The ignited material is then conveyed on the sintering machine, whereby the material ignited on a surface burns over the entire height of the material to be sintered. At the burn-through point, where the entire bed has just burned out in the vertical direction, the temperature measured near the windbox is greatest. Subsequently, the sintered material already cools down on further production on the sintering machine.

Usually it is desired that the sintering is completed at the end of the sintering machine or shortly before the end of the sintering machine. In any case, however, it should be avoided that the sintering process is not completed in the case of material discharge and the sintering process takes place on the subsequent cooling stations, which can be damaged by the heat generated during sintering. In addition, it should be avoided that the burn-through point is reached too early on the machine, as this leads to lower production.

In order to avoid this, the temperatures at the windboxes, in particular in the last quarter of sintering machines are considered in Durchbrennpunktpunktregelungen to determine the burn-through. In this case, the maximum temperature value is determined from the measured temperatures and from this the burn-through point is determined. It is determined by a comparison in which the windboxes the maximum temperature value prevails. This position is compared with the preselected position for the desired burn-through point.

If the windbox with the maximum measured temperature value is located in front of the selected position of the desired burn-through point, the conveying speed of the sintering machine is increased by a fixedly defined factor. If the windbox with the maximum measured temperature value lies after the selected position for the burn-through value, the machine speed is reduced by the same, fixed defined factor.

From the US 3,211,411 For example, a method and a device for controlling the conveying speed of a sintering machine are known. For this purpose, the temperature and the pressure of the exhaust air are measured in one of the several successively arranged wind boxes of a Dwight-Lloyd sintering machine and checks whether these measured values are in a desired range. This indicates that the sintering process is completed in the desired time frame or at the desired position of the sintering machine. In a sintering process, the temperature profile of the temperatures measured in successively arranged windboxes shows a maximum in the sintering point of the sintering bed. The measured pressure in the exhaust gases drawn in through the sintering bed remains approximately constant until it reaches the burn-through point and drops markedly after reaching the burn-through point. By a suitable combination of value ranges for the temperature and the pressure of the exhaust air suitably selected for the sintering machine and the process carried out, it can be decided at a selected windbox whether the process at the selected windbox of the sintering machine is in the vicinity of the burn-through point. Depending on the constellation of the two measured values, the conveying speed of the sintering machine is increased or decreased in order to place the burn-through point in the region of the selected windbox.

However, this control is comparatively expensive because two different measured values must be considered in order to be able to reliably determine the burn-through point. In addition, it may, for example, depending on the loading of the sintering machine on the grate carriage also to fluctuations in the absolute values come of the measured pressure. Therefore, this measured value is only conditionally suitable for controlling the transport speed of the sintering machine.

The US 4,065,295 describes in a comparable sintering machine, a method for controlling the conveying speed based on a measurement of the temperature measured in collectors of the windboxes. Control variable of the control is the temperature of all exhaust gases from all successively arranged on the sintering machine windboxes, which is measured in a manifold shortly before the intake fan. As a further control variable, the deviation of the average temperature of all exhaust gases is used, leaving the windboxes with a temperature of more than 100 ° C. This quantity reacts faster than the total temperature of the collected exhaust gases in the manifold. This method can also be used if the windboxes show no or only a maximum temperature which can be locally falsified by external influences. Alternatively, the determination of the maximum temperature in the successively arranged windboxes, which corresponds to the current burn-through point, is proposed as a second controlled variable in a cascaded control. The target burn-through point is determined based on the temperature of the exhaust gases in the manifold. This should compensate for inaccuracies in determining the maximum temperature, eg. In the last windbox. However, this regulation is complicated by the collection of two control variables. In addition, the regulation for setting a burn-through point can only be used if a maximum in the temperature distribution is also found. This is not the case, for example, if the material to be sintered has not yet been sintered through until the material is shed.

In the US 3,399,053 For example, a method and a device for controlling the conveying speed of a sintering machine are described in which the temperatures are measured in three windboxes arranged at the end of the conveying path and in the middle of the conveying path of the sintering machine in order to continuously readjust the conveying speed and set the desired burn-through point. From the three temperature measurements at the end of the conveyor line, the current maximum of the temperature distribution over the conveyor line is determined by adapting a parabola. This current maximum is compared with the desired position of the maximum, or the burn-through point, wherein a deviation of a change in the conveying speed of the sintering machine is derived.

From the temperature measurements in the middle of the conveyor line, a prediction of the rate of change of the position of the maximum temperature is derived.

The conveying speed of the sintering machine is then adjusted depending on the current maximum temperature and the predicted rate of change. By taking account of the predicted rate of change, it is also possible to take into account changes in the sintering characteristics, for example, subsequently introduced material, in a time-consuming manner. However, this method is subject to a great deal of uncertainty, because the individual temperature measurements each have comparatively large errors, which, in addition to possible systematic influences, are also influenced randomly by the composition of the sinter cake, which can not be precisely predicted. An adaptation of a parabola on the basis of such erroneous variables can lead to the fact that even the adaptation itself is faulty and the maximum of the temperature distribution is determined with a considerable distance to the actual maximum. The same applies to the prediction of the rate of change, resulting in an overall unstable regulation.

The object of the invention is therefore to propose a simple and robust way of controlling the conveying speed of a sintering machine.

This object is achieved by a method according to claim 1 and a controller according to claim 8.

In the method of the type mentioned above, it is provided that the course of the temperature of three, in particular exactly three, successively arranged measuring points is compared. Possibly. These measuring points can be arranged one after the other and / or separated from each other by other measuring points. When comparing the three measuring points, a maximum of the temperature is assumed if the first and third measuring points in the conveying direction have a lower temperature value than the second measuring point. Even if the invention is carried out particularly advantageously with the evaluation of exactly three measuring points, it is also possible to evaluate more than three measuring points, in which case, for example, the first and the last measuring point must have a lower temperature value than some or all of them lying in between middle measuring points to be able to determine a maximum. To determine a maximum is particularly advantageous in a sequence of measuring points of the invention Change point is sought, in which a sequence of increasing temperature values changes into a series of falling temperature values. This change point is then assumed to be the maximum of the temperature curve.

According to the invention, however, no maximum temperature is assumed if all measuring points, i. H. In particular, all measuring points selected in a relevant evaluation region form an ascending series of temperature values, so that no maximum is found, in particular in the case of three or more measuring points arranged one after the other. After determining whether or not a maximum can be assumed, assuming a maximum of the temperature, the conveying speed is set in accordance with a deviation of the positions of the measuring point with the maximum temperature value and the position of the selected burn-through point, whereas if no maximum temperature is assumed Conveying speed of the sintering machine is reduced by a predetermined value.

This also solves the problem with the previous maximum value consideration that it could not be determined with certainty whether the burn-through point of the material to be sintered was still on the sintering machine. It was quite possible that the burn-through point had not yet been reached due to an excessively high conveying speed of the sintering machine when the material to be sintered had already been thrown off the sintering machine before it had been completely sintered. Not only the maximum temperature value of the various measuring points is now considered by the method of spark-through detection proposed according to the invention, but an analysis of the course of successively arranged measuring points to be evaluated takes place, in particular by comparing the measured temperature of a measuring point with the previous and subsequent measuring points takes place. Only if the temperature values of both the previous and subsequent measuring points are lower than the temperature of the middle measuring point or of several middle measuring points, it is ensured that the burn-through point has actually been determined. If this is not the case, the control according to the invention proposes, in the case of a series of increasing temperature values up to the last measuring point, to reduce the conveying speed of the sintering machine in order to bring the maximum of the temperature of the material to be sintered into the region of the conveying path.

In an advantageous supplement to the control method according to the invention, the conveying speed can also be increased by a predetermined value if the first, second and third measuring points form a descending series of temperature values. This indicates that the material to be sintered has already reached its burn-through point before reaching the first measuring point. Also in this case no maximum is assumed.

According to the invention, a sequence of three measured values is sought in the at least three, but preferably more measuring points of temperature values, which show the above-described criterion for the detection of a maximum in the temperature profile. If such a maximum is detected, the search for the maximum can be aborted according to the invention. Alternatively, however, it is also possible to continue the search and thus carry out a consistency check of the measured values, for example to determine whether two maxima are detected. If this were the case, an error message of the control could be output, so that the sintering process is checked by other parameters, for example. As long, however, no maximum was found using the above criteria, in three consecutively arranged measuring points continues to search for maxima by each of the measuring points to be evaluated sequences of three consecutively evaluated measuring points are formed and checked, instead of the exactly three consecutively evaluated measuring points also more , For example, four or five, measuring points can be evaluated as already described. Thus, the search for the maximum is not limited to three measuring points, but always three successive measurements are compared with each other.

According to the invention, the measuring points can be measuring points located immediately one after the other on the conveying path. However, it is also possible according to the invention that the measuring points to be evaluated are defined by fixed test sequences of measuring points. In this case, it is also possible to use measuring points which are not arranged to be evaluated between successively arranged measuring points to be evaluated in the conveying direction.

A significant advantage of the proposed method, in comparison to the prior art discussed above, is that the temperature curve along the conveyor line is evaluated as the only controlled variable according to the invention. This makes it possible to provide a single sensor, namely a temperature sensor, per measuring point. This is particularly advantageous since the sensors used in technical installations such as sintering equipment must be robust, since otherwise they can be damaged quickly. The provision of several different sensors per measuring point therefore makes the control according to the invention considerably more expensive.

Since in conventional sintering machines the desired and selected burn-through point preferably lies shortly before the end of the conveying path on the sintering machine, the measuring points are preferably also arranged at the end of the conveying path before the material is shed, for example in the last quarter of the sintering machine.

Preferably, more than three measuring points are provided according to the invention in order to determine the maximum of a temperature distribution over a significant part of the conveyor line can. In conventional sintering plants, a number between four to six measuring points is particularly preferred according to the invention, which as a rule covers a sufficient area of the conveying path on the sintering machine. Normally, the sintering machine is divided into equal sections. Structurally, a segment width of 3 m has proven to be advantageous. Each of these segments has a windbox, with the last four windboxes halved to allow a more accurate determination of the burn-through point.

In a preferred embodiment of the method according to the invention, the measuring points can be arranged in the windboxes, preferably in windboxes arranged directly one after the other. Then, the maximum local resolution of the temperature distribution corresponds to the diameter or the extent of a windbox in the conveying direction, if in each windbox of the sintering machine or at least in each windbox of the sintering machine from the area of interest a measuring point is arranged. The measuring points are preferably located in the vicinity of the intake ports of the windboxes, in which the exhaust gases drawn in by the intake fan behind the windboxes are collected by the material to be sintered. The temperature of the exhaust gases is determined directly and significantly by the temperature of the material to be sintered, the temperature profile of these exhaust gases in particular follows the temperatures in the material to be sintered on the conveyor line.

Instead of an evaluation of the directly adjacent measuring points, three measuring points can also be selected from a multiplicity of measuring points arranged one after the other, wherein the first, second and third measuring points are arranged one after the other in the conveying direction, but measuring points not taken into account are arranged between the measuring points. As a result, a different width of the measurement curve can be taken into account.

This is particularly useful when a windbox in the conveying direction in several, d. H. two or more, segments is divided and is and is arranged in each segment, a measuring point is or is. In this case, the measurement can be carried out with an overall better resolution, since the conveyor line can be scanned with the resolution of the resolution provided in the windboxes. The segments can be logically divided by the different temperature sensors are arranged in different areas of the windbox. Possibly. can also be a structural separation of the segments, for example. By suitable baffles in the intake ports or funnels. According to the invention, it is particularly advantageous to arrange the several segments, in particular in the last third or fourth of the sintering machine, in which the selected burn-through point usually lies.

According to a particularly preferred embodiment, the amount of adjustment in the change of the conveying speed in the case of an assumed maximum of the temperature may be dependent on the value of the deviation between the position of the assumed maximum of the temperature and the position of the selected burn-through point. As a result, an adjustment in the direction of the desired or selected Durchbrunpunkts is accelerated depending on the deviation of the actual from the desired burn-through. The adjustment of the height of the adjustment can be done, for example, via the control parameters of the controller used, a P, PI, PID or other controller. Alternatively, a value table for different value ranges of the deviation can be specified, from which then the amount of adaptation of the change in the conveying speed is read off.

In the event that no maximum is found in the evaluation of the measuring points, the height of the adjustment can be fixed, d. H. a change in the conveying speed by a fixed value. The aim of this change is to shift the burn-through point to the sintering machine or into the area of the measuring points on the sintering machine so that a maximum is then found. Once the maximum is found, the above-described process of shifting the actual burn-through point to the selected burn-through point may occur.

According to a preferred variant of the proposed method, from an installation-specific burn rate, the composition of the material to be sintered, the task material height and the length of the sintering machine, preferably the length of the sintering machine between the ignition point of the material to be sintered and the selected burn-through point, an optimized conveying speed determined become. This theoretically determined, optimized conveying speed can be compared with the current conveying speed and / or taken into account when changing the conveying speed. The comparison of the optimized conveying speed and the current conveying speed can be used to find the suitable conveying speed for the process more quickly in order to quickly find the conveying speed to be set. In addition, the proposed comparison can be used additionally or alternatively to an installation-specific optimization of the burn rate, if a maximum of the temperature is found. The burn rate usually results from theoretical considerations of the plant, which can be specified by measurements in the current operation. In addition, the burn rate can be used to specify an approximate conveyor speed as the starting value of the control in order to keep possible control deviations small and to produce a small signal behavior of the control, which allows a particularly fast compensation.

In a further development of this feature according to the invention, a difference between the current, actual conveying speed and the optimal conveying speed can also be formed, wherein a warning message is output when a threshold value is exceeded. If necessary, the warning message can also contain an indication of a conveying speed to be set in a favorable manner, in particular if no maximum can be assumed or found when checking the measuring points.

According to the invention, the present invention also relates to a regulator for setting the burn-through point in a sintering machine. This controller has a computing unit and at least three connections for connecting individual measuring points associated temperature sensors and an output for specifying a conveying speed. Preferably, however, more temperature sensors can be connected to the controller, the number of measuring points optimally corresponding to the number of terminals. According to the invention, the arithmetic unit is adapted to carry out the above-described method or parts thereof, for example by means of suitable software.

A development of the controller according to the invention provides that the controller is integrated into a control device of the sintering machine, which predefines the conveying speed of the conveying path of the sintering machine. For this purpose, the controller can control suitable drive units of the conveying path, in particular of an optionally circulating conveyor belt or a trolley. The drive units can in particular be driven by an electric motor or hydraulically. According to the invention, it is provided that the output of the control for specifying the conveying speed is connected to a control input of the controller. This connection can also be realized in an integrated processing unit without recognizable outputs and control inputs, if the regulation and the control are implemented in a common microprocessor.

Preferably, temperature sensors may be connected to the or a few terminals, but at least three terminals, of the controller, which are arranged in the conveying direction on the conveyor line of the sintering machine arranged successively, preferably driven in the suction direction Windboxes and each form a measuring point.

A reliable temperature measurement can be carried out, in particular, when the temperature sensors are arranged in the suction device of the windboxes, for example, tapered slots or funnel-shaped openings. As a result, sucked through the material to be sintered exhaust gases from a well-defined area, in which a certain Durchbrenngrad of the material to be sintered is reached.

In order to increase the resolution of the temperature measurement, at least one suction device, but possibly also several or all suction devices, may be segmented in the conveying direction, wherein a temperature sensor is arranged as a measuring point in each case in several or all segments of the suction devices.

Further advantages, features and possible applications of the present invention will become apparent from the following description of an embodiment and the drawings. All described and / or illustrated features alone or in any combination form the subject matter of the present invention, also independent of their summary in the claims or their back references.

Show it:

1 schematically a according to the invention connected to the control of a sintering machine and connected to measuring points controller;

2 schematically the flow of a method provided according to the invention.

In 1 is schematically a sintering machine 1 represented on the granular or powdery substances, such as ores, are joined together by heating. For this purpose, the material to be sintered in a material task 2 on a, for example, designed as a circumferential grate conveyor line 3 given up. The conveyor line 3 moves in the direction indicated by the arrow F conveying direction. The material to be sintered is initially under a Zündhaube 4 performed, which ignites the material to be sintered on the surface.

During transport over the conveyor line 3 burns the superficially inflamed material to be sintered in its run height before it in the material dump 5 from the conveyor line 3 is dropped as a sinter, for example, to be fed to a subsequent process. As soon as the material to be sintered has burnt down, the sintering process is completed. The desired burn-through point D is selected in the process. Usually, the selected burn-D is in the conveying direction F just before the end of the conveyor line 3 and the material dump 5 ,

To promote the burning through of the material to be sintered, are below the conveyor line 3 wind boxes 6 provided, via a suction line 7 to a blower operated in the suction direction 8th are connected. The windboxes 6 have longitudinal slot formed suction 9 on, their biggest opening on the conveyor line 3 facing side, due to by the blower 8th generated negative pressure to suck the resulting in the burning of the material to be sintered exhaust gases. The windboxes 8th are each with their suction devices 9 adjacent to each other under the conveyor line 3 arranged for clarity in 1 not all windboxes 6 are shown. Also, the illustrated windboxes with their suction devices 9 not all provided with reference numerals for clarity.

In the before the material shedding 5 in the conveying direction immediately adjacent windboxes 6 , or more precisely in their suction devices 9 , are each measuring points 10 arranged, for the sake of clarity, not all provided with reference numerals.

The measuring points 10 each have one in the suction device 9 a windbox 6 arranged on the temperature sensor, the temperature of the sucked exhaust gases from the material to be sintered on the conveyor bed in the over the suction 9 arranged area measures.

In order to be able to name the different measuring points below, these are marked as measuring points M1 to M5. However, it is expressly understood that the invention is not limited to the provision of exactly five measuring points 10 is limited. Rather, their number by the skilled person to the particular circumstances of the sintering machine 1 be adapted, in particular the last third to quarter of the conveyor line 3 with suitable measuring points 10 is covered to the burn-through point in this area of the sintering machine 1 to be able to detect.

The measuring points M1 to M5 are provided via respective connections 11 to a controller 12 connected, in which the method described below takes place. In a unit with the regulator 12 is a controller 13 provided an output 14 to specify a conveying speed. This exit 14 is with a drive unit 15 the conveyor line 3 connected to the conveyor line 3 with the through the control 13 predetermined conveying speed in the conveying direction 3 to move. The regulator 12 and the controller 13 each have arithmetic units, possibly also a common arithmetic unit, which for carrying out the method described below and for driving the conveyor line 3 are set up.

The method proposed according to the invention for adjusting the burn-through point D of the sintering machine 1 In this case, the temperatures of the exhaust gases are measured at the measuring points M1 to M5. A typical temperature profile of these exhaust gases in a sintering machine provides that in the conveying direction successive measuring points 10 the temperature values rise until the burn-out point D is reached. After reaching the burn-D, the sintered material cools again, so that the temperature of the exhaust gases decreases. The temperature maximum is thus reached in the burn-D. According to the invention, the temperature profile measured in the measuring points M1 to M5 is analyzed, as described below with reference to FIG 2 explained.

It is assumed that in the method a total of M1 to Mn successively arranged measuring points are evaluated. For this purpose, the measured temperature values of the measuring point M (i-1), M (i) and M (i + 1) are compared with each other. It is started with the second measuring points M (i = 2) in the conveying direction and checked in a first query whether the temperature value of the measuring point M (i - 1) is smaller than the temperature value of the measuring point M (i). If this is the case, a comparison between the measuring points M (i) and M (i + 1) is carried out as the next check, wherein a maximum is detected at the position i when the temperature value at the point M (i) is greater as the temperature value at the measuring point M (i + 1). In this case, the position of the measuring point M (i) is set as the current burn-through point D (i) and the difference to the selected burn-through point D is formed. Depending on the height of this control difference, the conveying speed in the controller 12 or the controller 13 adapted, wherein the adaptation, for example, takes place due to a suitable parameterization of the control parameters.

If it is determined in the first request that the temperature value of the measuring point M (i) is not greater than the temperature value of the measuring point M (i-1), the next measuring point M (i + 1) is moved and the test is repeated until the last measuring point is reached. If, even for the last measuring point, the value M (i) is smaller than the measured value M (i-1), the conveying speed is increased by a constant K1 because the measured value sequence indicates that the burn-through point on the conveying path 3 before the first measuring point M1.

If, on the other hand, during the checking of a measuring point (in the next checking step) it is ascertained that the following measuring point M (i + 1) has a greater temperature value than the measuring point M (i), then the next measuring point is also transitioned until all measuring points have been processed are. If this condition also occurred at the last measuring point, there is an increasing number of temperature readings, which indicates that the burn-through point is behind the conveyor line. In this case, the conveying speed is reduced by a constant value K2.

By adjusting the conveying speed, the actual burn-out point D (i) shifts in the direction of the selected burn-through point D until no control deviation D (i) -D is present and the currently set burn-through point D (i) coincides with the selected burn-through point D.

This procedure is described below with reference to a concrete example with reference to the arrangement according to 1 explained again.

In a first considered case, the following temperatures are measured at the measuring points M1 to M5:
M1: 240 ° C
M2: 250 ° C
M3: 260 ° C
M4: 270 ° C
M5: 280 ° C.

In this case, there is an increasing temperature sequence and a maximum of the temperature distribution can not be assumed, since the temperatures continue to rise from one measuring point to the other. In this case, it can be assumed that the conveying speed of the sintering machine 1 is too high and the Durchbrunpunkt behind the conveyor line 3 lies. In this case, the right branch of the method according to 2 run through.

In a second case, the following temperature distribution is present at the measuring points M1 to M5:
M1: 250 ° C
M2: 260 ° C
M3: 270 ° C
M4: 260 ° C
M5: 250 ° C.

In this case, a lower temperature is measured at the measuring points M2 and M4 than at the measuring point M3. It can therefore be assumed that the current burn-through point D (i) is located at the measuring point M3. For the value i = 3, therefore, the middle branch of the flowchart is determined according to 2 run through and terminated after the determination of the maximum value of the temperature at the measuring point M = 3, the processing of the evaluation of the measuring points.

Instead, the difference between the current burn-through point D (i) and the selected burn-through point D is formed as a system deviation. Depending on the magnitude and sign of this deviation forming the difference now finds a correction of the conveying speed of the sintering machine 1 instead of. This means that the correction is greater the farther the actual burn-out point D (i) is away from the selected burn-through point.

In the case described above 2 should, as in 1 represented, the selected burn-D at the measuring point M4. However, the current burn-through point D (i) lies at the measuring point M3, so that the conveying speed is slightly increased in order to shift the actual burn-through point D (i) to the position of the measuring point M4.

If the actual burn-through point D (i) were in the region of the measuring point M1, this correction would be greater.

If the current burn-through point D (i) were behind the selected burn-through point D in the conveying direction, the conveying speed would be correspondingly slowed down.

As part of the determination of the conveying speed, the conveying speed of the sintering machine can also be optimized by determining the burn rate. Depending on the material composition results for each sintering machine 1 a specific burn rate at which the sinter bed burns in the vertical direction. If this burn-through rate is known or determined, a theoretically optimal conveying speed can be calculated from the current material height of the material to be dispensed and the length of the sintering machine or, in particular, the distance between the ignition point of the material to be sintered on the conveying path and the selected burn-through point become:

In one example, if the burnup rate determined for the equipment is 15 mm / min and the material height applied is 700 mm, the relevant sintering machine length from the ignition of the material to be sintered to the selected burnup point is 4.28 m / min. However, the values used in the example are only for explanation and must indeed be adapted to the sintering machine, driving style and material composition.

This theoretically determined, optimal conveying speed can be used in the determination of the conveying speed in the context of the proposed regulation, for example. By the controller, to provide a stable control and adapt the actual conveying speed as quickly as possible to the desired operation of the system, the structure the sintering machine and the need for sintering for the subsequent process depends. Taking into account these parameters, the plant operator can initially select the conveying speed suitably. With the selected conveying speed, the material to be sintered becomes the material task 2 until the material is shed 5 transported, with the surface of the sintered bed in the ignition hood 4 once ignited and the ignited layer of the sintering bed through the windboxes 4 is pulled down.

By selecting the burn-through point D, the plant operator determines at which position the sintered bed should be completely burned out. By the proposed control is now a fast and accurate displacement of the measured or actual Durchbrunpunktes D (i) to the preselected position of the burn-D, which is also achieved when no current Durchbrunpunkt D (i) can be determined because the current Burn-out point D not in the range of the measuring points M1 to M5 of the sintering machine 1 lies. In this case, the burn-through point initially in the direction of the measuring points M1 to M5 according to 1 postponed until the exact regulation takes effect. This is done by adjusting the conveying speed by fixed values.

For example. can be proposed in the context of the scheme and to accelerate the drive-through process the plant operator even then the optimized conveying speed when a difference from the currently determined Durchbrunpunkt D (i) and the selected Durchbrunktpunkt D exceeds a certain threshold amount.

LIST OF REFERENCE NUMBERS

1

sintering machine

2

material feed

3

conveyor line

4

ignition hood

5

material discharge

6

windbox

7

suction

8th

fan

9

aspiration

10

measuring points

11

connection

12

regulator

13

control

14

output

15

Drive unit of the conveyor line

F

conveying direction

D

through point

D (i)

assumed burn-out point, position of the maximum measured temperature

M1 to

M5 measuring points

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3211411 [0006]
• US 4065295 [0008]
• US 3399053 [0009]

Claims (12)

Method for setting the burn-through point (D) in a sintering machine ( 1 ), in which the material to be sintered on a conveyor line ( 3 ), ignited and arranged in the conveying direction (F) Windboxes ( 6 ) until a material dump ( 5 ) is transported, wherein at least three in the conveying direction ( 6 ) successively on the conveyor line ( 3 ) arranged measuring points ( 10 ) the temperature is measured and the conveying speed of the sintering machine ( 1 ) depending on the position of the maximum measured temperature (D (i)) is set to the position of the selected Durchbrunpunkts (D) on the conveyor line, characterized in that the course of the temperature of three consecutively arranged measuring points ( 10 ), wherein a maximum of the temperature is assumed, if the in the conveying direction (F) first and third measuring point ( 10 ) have a lower temperature value than the second measuring point ( 10 ), and wherein no maximum of the temperature is assumed if all measuring points ( 10 ) form an ascending series of temperature values, and in that, assuming a maximum of the temperature, the conveying speed is set as a function of a deviation between the position of the measuring point with the maximum temperature value (D (i)) and the position of the selected burn - through point (D); if no maximum temperature is assumed, the conveying speed is reduced by a predetermined value. A method according to claim 1, characterized in that the conveying speed is increased by a predetermined value when the first, second and third measuring point ( 10 ) form a descending series of temperature values. Method according to claim 1 or 2, characterized in that measuring points ( 10 ) in windboxes ( 6 ) to be ordered. Method according to claim 3, characterized in that a windbox ( 6 ) in the conveying direction (F) is divided into several segments and in each segment a measuring point ( 10 ) is arranged. Method according to one of the preceding claims, characterized in that the amount of adjustment in the change of the conveying speed in the case of an assumed maximum of the temperature of the value of the deviation between the position of the maximum of the temperature (D (i)) and the position of the selected Penetration point (D) depends. Method according to one of the preceding claims, characterized in that from a plant-specific burn rate, the task material height and the length of the sintering machine ( 1 ) an optimized conveying speed is determined and compared with the current conveying speed and / or taken into account when changing the conveying speed. A method according to claim 6, characterized in that a difference between the conveying speed and the optimal conveying speed is formed and when a threshold value is exceeded, a warning message is output. Regulator for setting the burn-through point in a sintering machine ( 1 ) with one arithmetic unit and at least three terminals ( 11 ) for connecting individual measuring points ( 10 ) associated with temperature sensors and an output for specifying a conveying speed, characterized in that the arithmetic unit for implementing the method according to one of claims 1 to 7 is set up. Regulator according to Claim 8, characterized in that the regulator ( 12 ) into a controller ( 13 ) of the sintering machine is integrated, which determines the conveying speed of the conveying path of the sintering machine, and that the output of the control for specifying the conveying speed is connected to a control input of the controller. Regulator according to Claim 8 or 9, characterized in that connections ( 11 ) of the controller ( 12 ) Temperature sensors are connected, in the conveying direction (F) on the conveyor line ( 3 ) of the sintering machine ( 1 ) arranged windboxes ( 6 ) and in each case one measuring point ( 10 ) form. Regulator according to claim 10, characterized in that temperature sensors in suction devices ( 9 ) of the windboxes ( 6 ) are arranged. Regulator according to claim 11, characterized in that a suction device ( 9 ) is segmented in the conveying direction (F), and that in several segments of the suction device ( 9 ) A temperature sensor is arranged.

Images