EA036991B1 - Method for uniformly feeding a continuous conveyor - Google Patents

Abstract

Provided is a method for uniformly feeding a continuous conveyor. The invention describes a method for feeding a continuous conveyor with granular material, wherein at least two loading devices are moved to each other such that by each loading device a continuous lane of the material is formed on a bearing area of the continuous conveyor. These lanes are parallel to each other and overlap such that a single material bed is formed on the bearing area which in a cross section is orthogonal to the bearing area and has the form of a trapezoid. The parallel sides of the trapezoid are parallel to the bearing area.

Description

The invention relates to a method for loading a continuous conveyor with granular material, in which at least two loading devices are moved towards each other so that each loading device forms a continuous strip of material on the supporting surface of the continuous conveyor, and these strips are parallel to each other and overlap in such a way that one layer of material is formed on the bearing surface, while the layer of material in the cross-section orthogonal to the bearing surface is trapezoidal, and the parallel sides of the trapezoid are parallel to the bearing surface.

Continuous conveyors or also elevators are conveying systems that generate a continuous traffic flow. They are especially suitable for transporting bulk flows of large quantities of material or constantly needed materials along predetermined routes. In addition, they are especially suitable for conveying granular materials. They are characterized by continuous and / or stationary movement and therefore differ from batch conveyors, which move the material to be transported in separate cycles.

Continuous conveyors are available as floor or non-floor systems. Floor-linked continuous conveyors are capable of conveying the transported material horizontally, obliquely and vertically. They have the disadvantage that they take up a lot of space and that the transportation route is predefined. In most applications, non-floor systems are limited to rails.

Continuous conveyors are automated devices and are designed to run smoothly, and therefore they are often characterized by a simple design as well as low energy consumption. In particular, they are used when materials and goods of the chemical industry are loaded and / or unloaded, in the mining industry, in open pit mining, in the production and processing of metals, in power plants, in line production, in a storage area, and elsewhere, when separate production stages are interconnected.

In the sense of the present invention, continuous conveyors are, in particular, mechanical conveyors and gravity conveyors. Mechanical conveyors are driven roller conveyors, vibratory conveyors, cyclic conveyors, carousel conveyors, belt conveyors, elevator wheel locks, bucket elevators, chain conveyors, screw conveyors and endless rope retractable systems, and trolley hitching. Gravity conveyors are, in particular, a spiral chute and any form of caterpillar, such as turntables, mobile roller conveyors and non-driven railways.

All of these continuous conveyors are characterized by the continuous transport of material that they carry, which also depends on their load. Consistent conveying of material on a continuous conveyor over time can only be achieved when the continuous conveyor is loaded absolutely evenly. Thus, the loading of the continuous conveyor directly affects the degree to which the downstream processes can usually be carried out in a steady state. Thus, loading is also directly related to handling, yield and / or product quality. To a greater extent, this is true when a continuous conveyor is loaded from different sources at the same time, that is, when it works not only as a vehicle, but, in addition, as a collector.

Until now, as a rule, the load has been corrected locally and manually. For example, raw iron ore pellets prepared by a plurality of pelletizing discs were loaded onto a single continuous conveyor made in the form of a belt conveyor, which thus served as a collector and served as a means for further transporting the raw pellets to the pellet kiln for thermal treatment.

In part, it was possible to adjust the granulating discs and / or discharge belt conveyors belonging to the granulating discs, which then transported the material to the continuous conveyor, in relation to their exact discharge position on the bearing surface of the belt conveyor manually or by means of a drive device, but the adjustment was carried out exclusively on site , manually and / or by visual inspection. This meant that the plant operator either had to be on site or rely on the factory's video cameras to figure out from the (TV) picture how the material was distributed, and in addition had to adjust the discharge belts accordingly, if at all possible.

Thus, it is an object of the present invention to provide a method for loading a continuous conveyor by which a completely stationary material flow can be achieved.

This problem is solved by creating a method characterized by the features of claim 1 of the claims. Such a method of loading a continuous conveyor with preferably granular material uses at least two loading devices. These two loading devices can be moved towards each other, and this, for example, for at least one loading device, can be realized with a suitable drive device, in particular hydraulic, pneumatic or (electric) motor. But it is also possible to realize the possibility of mechanical movement towards each other, for example, by snapping in different positions.

As such, the ability to move towards each other can be realized in a continuous or discontinuous manner, while being able to move continuously towards each other allows for better control of both loaders as they can occupy each position.

With each loading device, a continuous strip of material is loaded onto the supporting surface of the continuous conveyor, for example a belt conveyor. In accordance with the present invention, the two charging devices are here moved towards each other in such a way that the strips are parallel and superimposed on each other so that one layer of material is obtained on the carrier surface. In particular, in this connection, overlap means that by loading the strips with a loading device, a plane of granular material with beveled sides is obtained in the sense of an inclination determined by the bulk properties of the material, and that the sides of two beveled planes of granular material from said at least two loading devices overlap each other other so that one layer of material is obtained on the bearing surface, and the formed one layer of material in a cross-section orthogonal to the bearing surface has the shape of a trapezoid, while the two sides of the trapezoid, which are parallel to each other, are also parallel to the bearing surface of a continuous conveyor, such as, for example, a conveyor belt. According to the present invention, the said individual strips of said at least two loading devices thus form a trapezoidal profile as a whole, from which it may not follow that it consists of different discrete strips.

In practice, this means that the specified several cones or truncated cones of the granular material form a continuous truncated cone of the granular material, so that the largest bearing surface is the surface on which the material accumulates on the continuous conveyor, and the shorter side is the one that is parallel to the largest side and thus forms the upper region of the truncated cone of the granular material, and both side regions parallel to the edges of the continuous conveyor represent the cone of the granular material, which is determined by the properties of the material used.

Preferably, the material layer is formed parallel to at least one edge of the bearing surface with a deviation of at most 10 °, preferably 5 °, particularly preferably 2 °. This means that, for example, waves or winding stripes do not form in the transport area, since they can also lead to uneven loading. Therefore, the movement of one of these at least two loading devices must be carried out slowly with respect to the transport speed of the continuous conveyor.

In addition, it is preferable when the granular material contains iron. In particular, in the case of iron and steel production, mass flows of large quantities of iron ore are manipulated such that, in the example of transporting raw pellets from pelletizing discs to a pellet kiln designed as a moving grate plant, this method provides decisive advantages, since only uniform loading The grate carts of the moving grate can ensure that under the prevailing conditions in the plant, the material used is burned evenly and thus a uniform product quality can be achieved at the end of the process.

In addition, it has been shown that an advantage is obtained when at least one measuring device checks that side of the material layer which is parallel to the bearing surface with a distance D of at least one centimeter to it. This measuring device or these measuring devices check this side for minima and / or maximums and in this way discontinuities can be determined. When the measuring device detects such unevenness, the loading devices can again move towards each other in such a way as to again form a layer of material which, in cross-section, being orthogonal to the bearing surface of the continuous conveyor, has the shape of a trapezoid, and in which the sides of said trapezoid, which are parallel each other are also parallel to the bearing surface.

It has been shown that a particular advantage is obtained when a measuring device is selected that is capable of measuring the overall profile of the trapezoid on the bearing surface, so that it can be used to calculate the cross-sectional area of the profile. Thus, with its help, by multiplying by the transport speed of the continuous conveyor, it is possible to calculate the volumetric flow (volumetric flow) of the transported granular material. When, over time, by measurement and calculation, the change in the volumetric flow of the granular material is determined, then, on the one hand, the process step upstream can be changed in a controlled manner, for example, by changing the mass flow of iron ore to the granulating discs, which contradicts a certain change, to return the granular volumetric flow to the desired value, or on the other hand, a downstream process step such as, for example, a pellet kiln can be prepared for a modified granular volumetric flow in a feedforward control sense, for example, a corresponding change in speed moving the grate in the pellet kiln. In a feedforward process, fluctuations over time can be very reliably minimized since there is no need to wait for an error signal. This usually leads to a particularly high efficiency, in particular energy efficiency, of the entire process.

In addition, it has been shown that an advantage is obtained when the feeding devices are located on both sides of the continuous conveyor in the direction T of its transport one after the other. Thus, in the case of movement of the loading device, it is impossible to get confused, and in this case all the arrangement of the process steps upstream is more advantageous.

In this connection, a particular advantage is achieved when, starting from the second loading device, each loading device adds its corresponding strip to the strip already existing on the side of the carrier surface on which this loading device is located. This means that the first loading device forms the first strip on the carrier surface, preferably located in the middle thereof. Next to it, on the first side, there is a second loading device, which on this first side adds a second strip parallel to the first and overlaps it. Then, on the second side of the continuous conveyor, the third loading device adds a third strip, which is again added on this second side to the first strip in a parallel and overlapping manner. The fourth, sixth and finally the 2nd stripe are added from the first side to the second and finally to the (2p-2) th stripe, while on the second side the fifth and finally the (2p + 1) th stripe is added to the third and, finally, to the (2n-1) th band. When the full trapezoidal profile consists of an even number of stripes, then on the second side the (2n-1) th stripe is the outermost stripe, which is added to the (2n-3) th stripe in a parallel and overlapping manner.

In particular, in the case of at least three loading devices, it has been shown that an advantage is achieved by placing the loading devices on both sides of the continuous conveyor in its working direction one after the other in their positions P, so that the loading devices, starting from the said first loaded strip, add their strips in the positions of strips from 2 to 2n-e to the existing strip on the side of the bearing surface with which they are located. When a flatness defect of the entire trapezoidal profile in the form of a minimum or maximum is attributed to one loading device on one side and this corresponds to the complete failure of one loading device, then the loading device (s) located downstream of this loading station on the corresponding side is moved as follows that it occupies position (s) P-1 on the corresponding side, correspondingly the position that was upstream until now.

In the same way, the loading devices are located on both sides of the continuous conveyor in its working direction one after the other in such a position that the loading devices, starting from the first loaded strip, add their strips to positions from 2 to 2n or (2n + 1 ) -e. Here they add their stripes to the existing strip on the side of the bearing surface on which they are located. When, during the detection of flatness defects, a maximum is attributed to one loading device on one side, since it is switched on again and therefore the two lanes completely overlap, then the loading devices on this side are placed downstream one after the other relative to this loading device and moved so that they occupy position (P + 1), i.e. accordingly, the position that was hitherto in the downstream position.

In addition, it is also possible for the material flows of one loading device to increase or decrease. But even in this case, in the sense of the invention, a uniform profile can be achieved on a continuous conveyor. A precondition for this is that as a result of the increased material flow, the strip of material on the continuous conveyor will have a wider width, and as a result of the reduced material flow, the strip of material will have a narrower width. However, the heights of these strips of material remain unchanged, so that, as described, differences in height can only be caused by overlap of the strips of material that is too strong or too weak. Therefore, when the overlap of two adjacent stripes is too weak or too strong, a minimum or maximum may also occur in the profile of the entire layer. Then it is only allowed to move the next loading station slightly and all subsequent loading stations on that side to change the overlap in the direction of the ideal overlap, that is, the flat surface of the layer.

In order to ensure that the material flow only differs in the width of the loaded strip, it has been shown to be advantageous to design the loading devices themselves as continuous conveyors which are partially reloaded. This can be achieved by adjusting the speed of these loading continuous conveyors. Preferably, the speed of each continuous loading conveyor is proportional to the mass flow rate of the material conveyed thereon.

Due to the above described ability to move the loading devices, the path along which the loading devices have to move during the control / regulation operation is minimized. This simplifies plant construction and saves space. In addition, therefore, single loading devices can be removed from the system or can be added to it again in a relatively simple way, without the need for complex logistics, according to which

- 3 036991 defines where which boot device loads or adds which lane.

In addition, it has been shown that it is preferable when at each moment of time the layer of material is formed parallel to at least one edge of the bearing surface with a deviation of not more than 10 °, preferably 5 °, especially preferably 2 °. This means that the movement of the loading device relative to the movement of a continuous conveyor, for example a conveyor belt, is relatively slow. Preferably, in the present invention, the movement of the loading device is carried out at a speed that is 18% lower, preferably 9% lower, particularly preferably 3.5% lower than the conveyor belt speed. In this way, larger malfunctions can be prevented in subsequent stages of the process due to accumulation or lack of material. Here, the relationship between travel speed and conveyor belt speed can be calculated using the tangent of the desired angle. At large angles (correspondingly higher travel speed of the loading device relative to the speed of the conveyor belt), when the material is transferred to the continuous conveyor, in each case, a malfunction occurs. Accordingly, for example, when 10 ° movement is realized, the movement speed is 18% of the conveyor belt speed, and when 2 ° adjustment is performed, the movement speed is 3.5% of the conveyor belt speed.

But it may also be advisable to move very quickly when it is desirable again to guarantee a compact bed of material with a uniform material flow as quickly as possible.

Therefore, it is especially advantageous when, in the case of a complete absence of one strip of material, or in the case of complete overlap of two strips of material for a quick solution to the problem, the corresponding loading devices move at a speed of 17.5% of the speed of the continuous conveyor. But when only a small defect is found in the overlap of two adjacent strips, the respective loaders will only move at 1.75% of the belt speed in terms of fine tuning to prevent overshoot by the regulator.

When material is loaded from the first continuous conveyor to the second continuous conveyor, it is important that the discharge device adds parallel strips to the second continuous conveyor, which are ideally adjacent to each other, so that a continuous bed of material is achieved. Thus, in accordance with the present invention, the individual tracks that are loaded or added to the second continuous conveyor by the discharge device of the first continuous conveyor form a common layer of material that is formed in such a way that it cannot be seen that it consists of different single strips.

Until now, no control or regulation mechanisms existed for this, so the second continuous conveyor was loaded unevenly. Using the example of transporting raw iron ore pellets into a pellet kiln, it should be clarified what this means: the raw pellets are prepared on the so-called granulating discs and from these granulating discs, either through continuous conveyors, or they are directly loaded onto the first continuous conveyor to accumulate material. This first continuous conveyor loads a discharge device that moves across the width of the bed on a second continuous conveyor. This second continuous conveyor then feeds the material directly or through a screening step, for example by means of a roller screen, into a grid carriage, in which it moves along a chain of moving grates through the heat treatment area. But when the grid carts are loaded unevenly, this either results in material wastage due to too high a load, or the plant does not reach its theoretical maximum throughput because the loading of the single-grid carts is too low. When the single-grid carts are carrying a nominal load while others are carrying a lower load, then the gas distribution during heat treatment becomes uneven because the gas preferentially chooses a path that is associated with lower flow resistance, which means that the gas preferentially flows through the bed on the grid. trolley with low loading. On the one hand, this disturbs the uniformity of product quality, since the granules in the sieve trolleys are exposed to different technological conditions due to the different loads of the sieve trolleys, and on the other hand, the sieve trolleys either lose material due to overload, or the plant capacity is only partially used due to for too low load. When the pellet kiln is then operated so that the green pellets in the normal load sieves are still able to provide the desired product quality, then the kiln energy requirement per unit mass of burned pellets increases as the pellets on the low load sieves are burned out.

A system for loading material from one continuous conveyor to another continuous conveyor can also be found in other applications, in particular when the first continuous conveyor is used to collect material originating from different sources, and when the second continuous conveyor is located transversely relative to the first continuous conveyor. When a reversible belt is used as the unloading device, it is also possible that both continuous conveyors have the same conveying direction.

Due to the described problems of uneven loading of subsequent technological stages

- 4036991 second continuous conveyor, therefore, an object of the invention is to provide a method and a corresponding device by which material is transferred from the first continuous conveyor to a second continuous conveyor so that a stationary material flow is achieved on the second continuous conveyor. In particular, furthermore, due to the invention, hills and valleys in the direction T2 of the conveyance of the second continuous conveyor must be prevented.

In such a method, the first continuous conveyor, which is preferably, but not necessarily, loaded in accordance with one of claims 1 to 9 of the claims, conveys material with a layer of material M1 having an average width B1. Width in the sense of the invention means the measure that the layer of material is perpendicular to the transport direction T1 of the first continuous conveyor. This continuous conveyor transports material in the direction of the unloading device. This unloading device can be moved in two directions of movement, the first direction of movement being opposite to the second direction of movement. In the first direction of movement, the unloading device has a first movement speed v _A1 , and in the second direction of movement, the unloading device has a movement speed v _A2 . Here, the first direction of movement of the discharger of the first continuous conveyor corresponds to the direction T _{1 of the} conveyance of the first continuous conveyor. According to the prior art, the following is true here: v _A1 = v1. In practice, it is achieved that the unloading device does not discharge material onto the second continuous conveyor as it moves in the first direction of travel.

With regard to the unloading device, the second continuous conveyor is positioned so that the unloading device with both directions of its movement moves back and forth over the required width B2 of the material layer M2 on the second continuous conveyor. Furthermore, here the width in the sense of the invention corresponds to the extent to which the layer is orthogonal to the transport direction T ₂ of the second continuous conveyor. During transport, the discharge device continuously loads material onto a second continuous conveyor in at least one, usually a second, direction of travel. Here, in particular, it should be emphasized that this goal can be best achieved when the material flow of the first continuous conveyor to the unloading device is already stationary and when the bed on the first continuous conveyor in the orthogonal direction relative to the transport direction T1 ideally has a trapezoidal profile. This is preferably achieved using the method and the corresponding device, which are described in DE 102011191944 and the exhaustive description of which relates to the content of this application.

The basic idea of the invention is that the second continuous conveyor moves at a speed v2, the value of which is within the range that follows from the travel distance of the unloading device in terms of the width B _{2 of the} material layer on the first continuous conveyor, from the width B _{1 of the} material layer on the first continuous conveyor and from both speeds v _A1 and v _{A2 of} operation of the unloader. According to the invention, the following is true:

* 0.85 Βγ * 1.15 f® ² __1__dx + f ^B2 __1__dx ~ ^{2 -} __-__ dx + f® ² __-__ dx ^J o νΑ1 (χ) ^{αχ +} ^ vA2tf) ^J ° WO ^J ° v _A2 (x )

This formula represents the most general case, namely that the velocities vA1 and vA2 are different from each other and that both vary in width B ₂ . In practice, this is true, because it is impossible to accelerate the unloader at the turning points to the required speeds v _A1 or v _A2 in an arbitrarily short time. Within the range indicated in the inequality, it is possible to achieve that the unloader, during loading in one direction of movement, loads a strip of material onto a second continuous conveyor, to which then the next strip of material is added almost continuously and, thus, a continuous layer of M ₂ material is obtained on the second continuous conveyor. In this way, a continuous, ideally stationary flow of material can be obtained on a second continuous conveyor, so that also subsequent technological steps are fed evenly, which leads to increased productivity and / or homogenization of product quality. The following range is preferred

Bi * 0.95 Βγ * 1.05

[ ^Br 1 dx + f ^Sz - dx ~ ^V2 ~ f ⁵² - dx + f ^S2 - dx v _A1 (x) v _A2 (x) ^ax Jo vA1 (x) ^J ° vA2 (x) ^ax and B ₁ is especially preferred * 0.98V _± * 1.02 f ⁵² __1__dx + e __-__ dx ~ ^V2 ~ f ⁵² __-__ dx + f ⁵² __-__ dx ^j o vA1 (x) ^{+ i} o vA2 (x) Jo v _A1 ^ ^d v _A2 (x)

A profile is completely unbreakable when the following is true:

Bi

V ₂ = ------- l ----------------- l ----- Г® ² 1 i I Г ^ 2 1, v _A1 (x) ^dX v _A2 (x) ^dx

- 5,036991 and when the widths B1 and B2 are defined as the widths of the trapezoidal profiles at half height (ie the average width).

In the particular case of the invention, the first and second speeds v _A1 and v _{A2 of} displacement of the unloader, except for the algebraic sign, are identical, and they are almost constant during the operation time, so that uniform movement of the unloader is achieved in both directions. This provides a particularly simple form of the drive device for the unloading device.

According to the prior art, both travel speeds v _A1 and v _{A2 of} the unloading device are equal to the transport speed v _i of the first continuous conveyor, so that the unloading device in the first direction of travel does not discharge material onto the second continuous conveyor, and so that in the second direction of travel of the unloading device exactly one strip of material is loaded onto the second continuous conveyor. In this case, and when the deceleration and acceleration processes in the area of the pivot points are ignored, in accordance with the present invention, the following simplified formula is valid for calculating the transport speed v2 of the second continuous conveyor:

Vi B-, 14 Β-, - * - * 0.85 <ν ₂ <- * - * 1.15 2 Β ₂ '- ² - 2 Β ₂ '

An additional embodiment of the invention is also possible, in which the unloading device loads two strips of material one on top of the other onto a second continuous conveyor, and, as above, only in the second direction of movement of the unloading device, the material is loaded onto the second continuous conveyor. This means that each strip overlaps by 50%, which means that the first strip is loaded onto a second continuous conveyor, and half the width of this first strip is loaded with half the width of the second strip, while the other half of the width of the second strip forms a new strip, on which then, in turn, is loaded with half of the third lane, while the other half of the third lane forms a new lane. In this way, higher material loads can be achieved in the second continuous conveyor. Then, for the speed range v _{2 of} transporting the second continuous conveyor, the following is true:

B _g - * - 4 B ₂

B _± 0.85 <v ₂ 1D5

AT ₂

When the conveying speed v ₂ of the second continuous conveyor is adjusted according to one of the above formulas, then absolute control is achieved.

In addition, it has been shown to be advantageous when the layer of material on the first continuous conveyor has a trapezoidal cross-section orthogonal to the bearing surface of the continuous conveyor, since a uniform loading of the second continuous conveyor can be ensured. In addition or alternatively, the average width B1 is the average width of this trapezoid, which is determined in the orthogonal direction with respect to the transport direction T ₁ of the first continuous conveyor.

In addition, it has been shown to be advantageous when the granular material contains iron. Particularly in the case of iron and steel production, large quantities of material are processed, and the example of transporting raw pellets from the pelletizing discs used for their production to combustion in a moving grate plant shows that this method is associated with decisive advantages, since only uniform loading of the grate carriages of the moving grate can guarantee that under the existing conditions in the plant the material used burns evenly and that at the end of the process a uniform product quality can be obtained.

In addition, it has been shown to be advantageous when the first measuring device checks the bed of material on the first continuous conveyor for minima or maxima in the longitudinal and transverse directions relative to the transport direction T ₁ of the first continuous conveyor. In this way, it can be determined when already the first continuous conveyor begins to load unevenly, and from this point on, measures can again be taken to ensure a steady flow of material.

Another preferred embodiment of the invention includes the fact that the second measuring device examines the presence of minima and / or maxima of the material loaded onto the second continuous conveyor. In this way, it is possible to determine if uneven loading occurs. When also the bed of material on the first continuous conveyor is checked for minima or maxima, the results of the second measuring device can be compared with the results of the first measuring device and thus the influence on uneven loading of the first continuous conveyor can be eliminated.

But when, in the course of time, only the second measuring device detects minima, which, moreover, appear periodically, at least three times one after the other with a periodic travel time to and fro in the direction of unloading, this means that the speed of the second continuous conveyor must be adjusted in terms of regulation. When periodic minima are found in the remaining 6036991 almost horizontal profile, then the speed of movement of the drive unit of the second continuous conveyor (thus its transport speed v ₂ ) must be reduced. This is preferably accomplished by gradually decreasing the transport speed of the second continuous conveyor. The reason for this is that minima are caused by the gap between the two strips loaded by the unloading device, or insufficient overlap between the two strips.

However, when periodic maxima are formed in the rest of the nearly horizontal profile at the periodic back and forth travel times in the unloading direction, then the travel speed of the drive unit of the second continuous conveyor and / or its transport speed must be increased, because the cause of these maxima is the double layer in the edge region. two strips loaded by a discharge device onto a second continuous conveyor. This is preferably achieved by very slowly increasing the speed of the second continuous conveyor until the maximum can no longer be detected.

In this case, the decrease or increase in the conveying speed v ₂ of the second continuous conveyor is preferably only 1% in 15 seconds. The reason for this very slow speed change is the lag time, which elapses when the change in the distance between the two lanes loaded by the unloading device does not reach the measuring device. In addition, it follows that the measuring device should be located as close as possible to the first continuous conveyor so that the lag time is short.

In a specific example, this means that for B ₁ = 2 m, B ₂ = 4 m, v ₁ = 0.8 m / s and the distance y * between the edge _{of the} material layer M ₁ on the first continuous conveyor, farther from the measuring device = 3 m, the speed range v _{2 of the} transport of the second continuous conveyor is calculated by the following formula:

Vi В-, Vi Β-, * 0.85 <v ₂ <ν * * 1Д5 o ₂ 2 B ₂

From the product of 0.85 and 0.2 m / s as the specific minimum value and the product of 1.15 and 0.2 m / s as the specific maximum value of this range, an average value of 0.2 m / s follows. Thus, to move a distance of 3 m for a layer M2 of material on the second continuous conveyor, an average of 3 m / (0.2 m / s) = 15 s is required. If, during these 15 seconds, the travel speed of the second continuous conveyor is changed by more than 1%, then there is a risk that the regulator will over-adjust, which must be prevented.

In general, the transport speed v2 should preferably be increased in increments of 0.1 m / s, particularly preferably 0.05 m / s, particularly preferably 0.01 m / s. In the case of larger increments, there is a risk that the control chain will overshoot.

For most process steps, uniform loading is the ideal loading, since in this way the stationary material flow and therefore also the stationary conditions in subsequent process steps can be controlled. There are also methods and devices in which the formation of profiles during loading at subsequent technological stages is reasonable, while the mass flow of the loaded material remains constant over time. An example of this is the combustion of so-called raw iron ore pellets, binder, water and optionally solid fuels in pellet kilns, which are designed as moving grate installations. Until now, the green pellets were loaded onto so-called lattice carts, and the loading was usually carried out in such a way that a horizontal line was formed between the upper edges of the side walls of the lattice carts, as well as a horizontal plane was formed in the layer in the direction of movement of the lattice carts. This is due to the advantage that the exhaust hood for guiding the gas above the pellet bed used in a moving grate plant can be constructed relatively simply with horizontal bottom edges, and that between the surface of the pellet bed on movable grate carts and a fixed bottom edge of the exhaust hood only a small gap formed. In this way, small leakage flows can be achieved between the inside of the fume hood and the environment of the installation. The lattice carts themselves move in a closed circuit in a circle and thus they are also a continuous conveyor.

But usually in such installations it is only checked to what extent the average layer height in the loading area of the moving grate corresponds to the corresponding process conditions, and not how the shape of the layer itself is arranged. As a rule, in this case, the average layer height is adjusted by changing the speed v _{4 of the} movement of the moving grate so that it matches the height of the side walls S of the grate carts. In this case, the unnecessary waves and asymmetric surface shapes of the pellet bed on the moving grate are not automatically corrected, although they can indeed have an unpleasant effect on the pellet combustion process.

But even when the ideal horizontal surface of the granule bed is reached, this profile is connected

- 7 036991 with two disadvantages. On the one hand, the filling degree of the horizontal profile is lower than the filling degree of the convex profile in relation to the load-bearing surface of the lattice carriage, because in the case of a convex profile with the volume of the vaulted part, an additional filling volume is created above the horizontal profile.

On the other hand, the gas flow inside the grate carriage is not uniform, especially in the combustion zone. The reason for this is that the temperature profile of the hot flue gases is not uniform across the width of the hood (thus in the x direction). Hot flue gas is present in the combustion zone in the exhaust hood, and at low pressure in the ventilation chamber under the grate trolley, it is sucked in through the pellet bed. In most pellet kilns, the flue gas in the center of the fume hood is at a higher temperature than the flue gas at the edges of the fume hood. This leads to different flow conditions in the bed of granules of the sieve cart, with more heat transferred from the flue gas to the pellets in the center of the sieve trolley, so that the pellets in the center reach the required quality in a shorter time than the pellets at the edges of the sieve cart. When the pellet kiln is then operated so that the pellets located on the rim reach the desired quality, then the pellets in the center are burned, which is undesirable and leads to an unnecessarily high energy requirement of the pellet kiln. It becomes clear that uniform loading of a pellet kiln with a horizontal layer profile, which is directed to the bearing surface R of the grate carriage (formed by the crossbars and the grate rods located on it) or another continuous conveyor, for example also a belt dryer with heat treatment on a perforated conveyor belt, thus however can lead to uneven product quality and thus even an undesirably high energy requirement. When a convex profile is formed, in which its maximum height is located in the center of the lattice carriage (the center, in the sense of the present invention, is mainly the center of mass of the rectangle or trapezoid formed by the bearing surface R and the lateral boundaries S), then here, due to the greater height of the layer the volumetric flow of hot flue gas passing through it in the combustion zone also decreases. Consequently, by purposefully varying the layer height, it is also possible to ensure uniform process conditions within the screen carriage across the width of the screen carriage.

In the case of other special features of the installation, it may be advisable to adjust asymmetric profiles (i.e. profiles having a maximum that is not centrally located between the side walls). For example, problems caused by special flow characteristics can be balanced as a result of the asymmetric geometry of the ventilation chambers below the grill trolleys.

Therefore, an object of the invention is also to provide a method and a corresponding device with which it is possible to purposefully create material bed height profiles over the width of the material bed on a continuous conveyor. Here, the bed width of the continuous conveyor material is the dimension of the bed in an orthogonal direction with respect to the conveying direction of the continuous conveyor.

Therefore, an object of the invention is also to provide a method and a corresponding device with which it is possible to purposefully create material bed height profiles over the width of the material bed on a continuous conveyor. Here, the bed width of the continuous conveyor material is the dimension of the bed in an orthogonal direction with respect to the conveying direction of the continuous conveyor.

This problem is solved by creating a method characterized by the features of claim 1 of the claims.

In such a method, by means of a first continuous conveyor, the material in the material layer having an average width B1 is transported to or onto the discharge device. It is preferable that the layer of material on the first continuous conveyor in the cross-section of the material orthogonal to the direction of transport T1 has the shape of a trapezoid, with both parallel sides of the trapezoid also parallel to the bearing surface of the first continuous conveyor. Therefore, in particular, the average width B ₁ is the average width of the trapezoid thus formed.

The unloading device is moved in the first movement direction L _A1 at the first movement speed v _A1 and in the second movement direction L _A2 with the movement speed v _A2 , wherein the orientations of both movement directions are preferably opposite to each other, and the first movement direction LA1 corresponds to the conveyance direction T1 first continuous conveyor. The opposition to each other in the sense of the invention, in particular, means that the discharge device moves along the width B2 of the layer of material of the second continuous conveyor, and here the movement does not necessarily describe a straight line distance. The width B _{2 of the} layers of material on the second continuous conveyor is to be understood, in the sense of the invention, in an orthogonal direction with respect to its conveying direction T2, and thus in practice generally means the width of the bearing surface of the second continuous conveyor minus the safety distance on both parties.

- 8 036991

The discharge device continuously feeds material in at least one direction of travel, preferably in the direction of travel LA2, onto a second continuous conveyor. The object and basic idea of the invention is that during the process of loading the material onto the second continuous conveyor by means of the unloading device, the speed v _{2 of the} movement of the unloading device changes and therefore is not constant. This means that the travel speed v _{2 of} the unloading device has at least three minima and / or one maximum along the width B2. This follows from the fact that also during normal operation at the beginning and at the end of its run, i.e. in the position x = 0 and x = B2, reaches its minimum, since the discharge device slows down when it is approaching to the turning point, and a position of x = 0 and x = B ₂ to move speed the following is true: v ₂ = 0. In addition in addition, according to the present invention, there is at least one additional minimum and / or at least one additional maximum.

Thus, in general, the travel speed v _{A2 of} the unloader becomes a function of position:

V _A 2 = / W = V _A2 (X) and the operating time of the unloader in the direction L _{A2 of} travel is determined as follows:

^L2 Jo V _A 2 ( ^x )

B ₂ dx = ——

V _A 2

Then, for the average speed v _A2 * of displacement of the unloading device during its run in the direction L _{A2 of} displacement, the following is true:

AT ₂

Va 2 - τ _Α 2

This means that when the local velocity v _A2 (x) of displacement of the unloader is lower than the average displacement speed v _A2 * of the unloader during its travel in the direction L _{A2 of} movement with a steady stationary material flow on the first continuous conveyor, locally more material is loaded to the second continuous conveyor. But when, on the contrary, the local speed v _A2 (x) of movement of the unloader is higher than the average speed v _A2 * of movement of the unloader, then with a stationary material flow on the first continuous conveyor, locally less material is loaded on the second continuous conveyor. The reason for this is that the amount of locally loaded material directly and reproducibly depends on the local velocity v _A2 (x) of movement of the unloading device in the direction L _{A2 of} movement, as long as the material flow on the first continuous conveyor is stationary, i.e. constant over time. Thus, with the help of the invention on the second continuous conveyor, maxima and minima and profiles along the width B _{2 of the} material layer (x direction) can be purposefully created, while the height of the material layer in the y direction is ideally constant in each x * coordinate (0 <x * <В ₂ ), even if it is not equal to the height of the material layer on the second continuous conveyor in a different coordinate x ** (0 <x ** <В ₂ , x ** ^ x *).

In a preferred embodiment of the invention, the variable speed v _A2 (x) of movement is characterized by a minimum in the middle of the width B _{2 of the} material layer of the second continuous conveyor. In this way, on the second continuous conveyor, a maximum can be reached in the middle of the material bed, for example so that in the case of loading the lattice carts, a convex profile effect is possible. But in general, this advantage can be used in every load where the throughput of the subsequent stages of the process plays a role. The height of each maximum is determined by the angle β of repose of the respective granular material, since the angle of repose cannot be exceeded. Thus, the maximum height that is possible in the middle of the width B ₂ layers of material on the second continuous conveyor will be determined as follows:

B ₂ ^ max ^- ”2” * ΐαηβ and the profile of the layer of material on the second continuous conveyor, which is created in this way, will be an isosceles triangle, and the length of its base will be B ₂ , and its height will be h _max .

In addition, it has been shown that an advantage is obtained when, starting from an axis extending in the working direction of the second continuous conveyor through the middle of the width B _{2 of the} second continuous conveyor, the travel speed v _A2 (x) changes symmetrically. In this way, symmetrical profiles are achieved, which usually correspond to the requirements of installations and ensure that uniform conditions are maintained in subsequent stages of the process.

Preferably, the unloading device discharges material in only one direction of travel LA2. In the other travel direction LA1, the average travel speed v _A1 * is exactly equal to the transport speed of the first continuous conveyor. This corresponds to the current mode of operation.

- 9 036991

In addition, it is particularly advantageous when the layer profile h (x) of the material on the second continuous conveyor can be calculated as follows:

h (x) = ax ² + bx with a <0 m 0 <b <1

In this way, a parabolic cross-section of the material layer orthogonal to the conveying direction T2 on the second continuous conveyor can be achieved, and thus the previously mentioned convex profile can be obtained. In a particularly preferred embodiment of the invention, b is the tangent of the repose. Thus, the created convex profile is characterized at its edges by the angle of repose and is flatter in the middle, because the first x derivative of the above equation gives the slope dx 'that is the tangent of the corresponding angle. Thus, the first derivative is:

h '(x) = 2ax + b while in position x = 0, thus the following is true: h' (0) = b.

But in general, you can also adjust other profile shapes, in particular arcuate, triangular, trapezoidal and concave profiles.

Here, preferably as described above, the layer of material on the first continuous conveyor has a trapezoidal shape. In this regard, the trapezoidal shape means that a cross-section is formed passing through the material orthogonal to the carrying surface of the continuous conveyor, in which both parallel sides of the trapezoid are also parallel to the continuous conveyor and / or its carrying surface. Therefore, in particular, the average width B1 is the average width of the trapezoid thus formed.

This design ensures that the strip of material loaded by the discharge device onto the second continuous conveyor also has a trapezoidal cross-section. Thus, the upper edge of this trapezoidal strip profile is parallel to the bearing surface of the second continuous conveyor. This is the best imperative for a constant bed height on the second continuous conveyor in the y direction at each coordinate x = x *, 0 <x * <B2. This is preferably achieved using the method and the corresponding device, which are described in patent document DE 102011191944 and which in their exhaustive description refer to the content of the disclosure of this application.

In addition, it has been shown to be advantageous when the first measuring device checks the bed of material on the first continuous conveyor for minima or maxima in the transverse direction (y-direction) and / or the second device checks the material loaded on the second continuous conveyor for periodic minima or maxima over time, thus in the stationary case the measuring device also checks the layer of material on the second continuous conveyor that passes underneath for periodic minima and maxima in the y direction.

It is necessary to check the first continuous conveyor with a measuring device, since it is necessary to ensure that the material flow on the first continuous conveyor is stationary and that ideally the layer of material on the first continuous conveyor always has the same trapezoidal profile having an average width B ₁ which is constant with over time and in relation to position. If this is not the case, then even an optimally adjusted control device cannot create the required profile h (x) on the second continuous conveyor by varying the position-dependent travel speed vA2 (x) of the unloader.

Periodic changes in the height h of the layer on the second continuous conveyor over time, in particular during the periodic movement of the unloading device back and forth, are detected by the second measuring device. They indicate that the conveying speed v ₂ of the second continuous conveyor is not precisely adjusted to the average travel speed v _A2 * of the unloader. Rather, in the case of detecting periodic minima occurring during the periodic movement of the unloading device back and forth, the second continuous conveyor runs too fast, so that the unloading device is unable to uniformly load and / or sufficiently overlap the strips on it. But when, over time, there are periodic peaks occurring at the periodic time of movement of the unloader back and forth, this means that the second continuous conveyor relative to the average speed v _A2 * of movement of the unloader is too slow, since the overlap of the strips of the material bed by the unloader is too strong. ... In this way, these inhomogeneities in the material bed over time on the second continuous conveyor, which are detected by the second measuring device, can be corrected by a suitable control mechanism. This is preferably achieved by a method and a corresponding device, which are described in patent document DE 102011191944 and which, in their exhaustive description, relate to the content of the disclosure of this application.

In addition, it has been shown that a particular advantage is obtained when the third measuring device measures the actual flow profile of material with width T ₄ loaded onto the fourth continuous conveyor at conveying direction T ₄ and conveying speed v ₄ , and when the regulator correlates the actual condition thus measured with the desired condition representing the ideal bed profile of the material on the fourth continuous conveyor. Thus, the desired profile condition on the fourth continuous conveyor can be precisely achieved by regulation. Here, the required profile on the fourth continuous conveyor, as well as in the case of the required profile on the second continuous conveyor, can be rectilinear, convex, triangular, arcuate, parabolic, trapezoidal or also concave, respectively symmetrical about the center line of the fourth continuous conveyor or also asymmetric with respect to her. When the fourth continuous conveyor has restrictions on the sides S, elevations, raised edges of the conveyor belt or side walls, then the height of the required profile at the edges of the width B ₄ can also be> 0. This is absolutely reasonable for the gas flow passing through the bed of material on the fourth continuous conveyor in terms of heat treatment, since otherwise the flow resistance in the edge region would be very low. This would result in the passed gas flowing preferably at the edges of the material bed, however where it does not encounter much solid matter. The result would be a low thermal efficiency of the heat treatment.

Thus, the required profile on the fourth continuous conveyor differs from the required profile on the second continuous conveyor, where the height of the material layer at the edges of the B2 width is always 0.

This third measuring device should be used in particular when a third continuous conveyor with a conveying direction T3, conveying speed v ₃ and material layer width B ₃ is still arranged between the second and fourth continuous conveyors. In practice, for example, a so-called roller screen with driven rollers is often used as a third continuous conveyor, where the transport direction T3 coincides with the transport directions T2 and T ₄ , the widths B2, B ₃ and B ₄ of the material layers usually differ only by a maximum of 20% , preferably less than 10%, but all transport speeds v ₂ , v ₃ and v ₄ are different from each other. The roller screen, in addition to its conveying function, also serves as a sieve for material grains that are too small and / or too large. In addition, this tends to homogenize the cross-sectional profile h ₂ (x) on the second continuous conveyor, in particular to reduce the convex elevation in the middle of the profile. Thus, in a regulatory sense, this roller screen results in an error. Since this is a particularly preferred embodiment of the invention, the profile h ₂ (x) on the second continuous conveyor changes until the desired profile h ₄ (x) is obtained on the fourth continuous conveyor. For this, a measuring device above the second continuous conveyor is useful, but not necessary.

For example, said measuring devices can provide continuous or discrete measurement results, where the terms continuously and discretely mean both measurements in time and in relation to local measurement points in the direction of movement of the first, second or third or fourth continuous conveyor, as well as along the width B1 , B ₂ , B ₃ or B ₄ layers of material. Typically, several sensors are used for each measuring device, which determine, in a discrete or continuous manner, the entire width of the respective continuous conveyors. These measurements can also be carried out continuously or within unit intervals, wherein during operation of the unloading device at least two, preferably at least four, measurements are made in each of the two directions of movement. Frequent measurements have the advantage that small deviations from the corresponding required profile can also be identified, and that it is easier to distinguish repetitive irregularities with the second measuring device, which are the result of an imperfect adjustment between the average speed v _A2 * of movement of the unloading pulley and the speed v _{2 of the} second continuous conveyor, and other deviations.

The measuring devices can detect discrete or continuous differences between the actual state and the desired state of the heights, h _desired (x) and h _actual (x), across the widths B ₂ , B3 or B _{4 of the} loaded layers on a second or downstream continuous conveyor. Thereafter, in accordance with the present invention, the speed of movement of the unloading device in the direction (s) of loading the material is controlled depending on the x coordinate. For this, the previous vector velocity ^r oZ <t ( ^x ) during material loading in one or both directions L _A1 and LA2 of the displacement is changed in such a way that the required new vector velocity ^r peg, pog ( ^x ) during a constant time τ of material loading will be equal to:

Vnew, normed (Л) ^- I ^ old (. ^ *

C ^B 2 ¹ L ⁰ Vnew (Λ) to I rJ desired I 2

- 11 036991 where α is a dimensionless attenuation coefficient that is <1, preferably <0.5, particularly preferably <0.2. With an appropriate selection of the damping factor, overshoot of the regulator can be avoided.

EA2, new (^) is the new operating speed of the unloading device, preferably the unloading pulley, sampled as a vector and defined as follows:

Vnew (x) = V _O ld (x) * ^ actual (Л) ^b desired (jX) _Л

------------- B ------ * a + 1 h

desired

The details and considerations regarding the control mechanism will now be explained even more specifically for a system in which a third measuring device transmits the actual height profile h ₄ , _actual (x) to the fourth continuous conveyor, whereby the required profile h ₄ , _desire d (x) is stored in the connected a regulating device, and in which the unloading device loads material only in the second direction of movement LA2 during the time TA2. However, considerations can be directly transferred to any other system.

When the regulating device connected to the third measuring device detects the difference between the actual and the required state of the cross-sectional profile of the layer on the fourth continuous conveyor during one discharge cycle, that is, during one complete movement of the discharge device in both directions LA1 and LA2 of movement, the new speed displacement, defined as a vector and sampled as RuncwW of the unloading pulley, can be calculated according to the following equation:

^ A2, new (/ ^- VA2, old (/) * ^b 4, actual (*) ^b 4, desired (*),.

--------------- B ------- * a + 1 ^b 4, desired where h ₄ , _desir e _d (x) and h ₄ , _actual (x) represent are the heights of the required and actual layer profiles on the fourth continuous conveyor, sampled in vector form. Here it is only required that sampling ^p A2 lead ^x ') be carried out with the same number of steps as the sampling of the profiles h ₄ , desi _red (x) and h ₄ , _actual (x) of the layer on the fourth continuous conveyor, even in the case when the widths The ₂ and B ₄ layers of material are different.

Thus, for example, the travel speed ^r A2 ( ^x ) of the unloader and the layer profiles on the fourth continuous conveyor can be sampled in 41 uniform steps, so that they can be expressed as vectors, each containing 41 lines. Then the 21st line, that is, the line in the middle of the equation, is written in vector form as follows:

ί ^ 2 \ _ ^ A2, new I 2) ^- ^ A2, old I 2) * h

-4, actual - h l — t] -4, desired I 7 I

---- B --------- * a + 1 ^b 4, desired

When in this example the actual profile height on the fourth continuous conveyor at the centerline of that conveyor is 45 cm and thus 5 cm above the required profile height at that position (40 cm in this example), then the fraction in this equation is + 0.125. If α is set to 0.1, then the value in square brackets in the equation is 1.0125. Thus, the new travel speed of the unloader along the centerline of the second continuous conveyor is increased by 1.25% over the old travel speed in the same position. All other 40 lines of the equation written as a vector are calculated in the same way.

During several cycles of movement of the unloading device using the dimensionless damping coefficient α, the profile of the velocity ^ν Α2 (X) of movement can be vectorially adjusted so that on the fourth continuous conveyor an actual profile 4 can be obtained, which corresponds to the required profile ^b 4, desired ( X)

Therefore, this adjustment of the profile h ₄ , _desir ed (x) can be influenced by a change in the profile W *) of the speed of the unloading pulley above the second continuous conveyor. This is critical because the solution that involves mechanical profile correction by skimming cannot be used in many processes, for example also in the case of iron ore pelletizing plants, since mechanical skimmers can damage the granular material. For example, in the case of raw iron ore pellets, each mechanical stress easily leads to their plastic deformation. Therefore, it is quite possible that the raw pellets under the influence of the skimmer are flattened at the points of contact with the skimmer or with neighboring granules, which leads to a decrease in the porosity of the granule layer and, consequently, to a decrease in permeability. Ultimately, the energy requirement for burning the pellets will increase, which is undesirable.

- 12 036991

It is preferable when the unloading device unloads material only during the movement direction LA2. Thus, only the movement speed ^Г А2 W in this movement direction LA2, depending on the x coordinate of the unloading device, also changes. In principle, the average movement speed v _A2 * can be chosen arbitrarily, but it is limited by the technological limitations of the conveyor technology. In particular, the use of very high power drive units should be avoided to accelerate masses of such a weight that cannot be ignored for structural and financial reasons. In the other direction L _{A1 of} movement, in which the unloading device in the preferred form of the invention does not load material onto the second continuous conveyor, it is advantageous when the unloading device moves at a speed v1 of the first continuous conveyor so that there is no relative movement between the unloading device and the carrying surface of the first continuous conveyor ... Thus, in this case, the material remains directly at the outlet edge of the unloading device and even when the unloading device slows down, thus, even before the start of material loading in the direction LA2 of movement, the material is again metered onto the second continuous conveyor. This has been shown to be advantageous when the acceleration and deceleration processes of the unloading device at pivot points in the direction of travel are as short as possible, preferably <3 s and particularly preferably <1 s.

In a specific example, this means that the first continuous conveyor is moving at a speed of 0.5 m / s. Thus, the speed v _{A1 of} movement of the unloading device in the direction L _{A1 of} movement (forward movement) at which the unloading device does not load material is also 0.5 m / s. Provided that the width B _{2 of the} second continuous conveyor is 4 m, the duration of this movement, when the acceleration and deceleration processes are ignored, is 8 s. For the average speed v _A2 * in terms of the average speed of the unloader in the travel direction LA2 (backward travel), 0.25 m / s can be selected so that the backward travel time TA2 in the case of the second continuous conveyor width B ₂ = 4 m is 16 seconds. Thus, in this example, a complete unloading cycle of the unloader takes a total of 8 s + 16 s = 24 s.

Now the profile ^r Ar ( ^x ) of the unloader speed is selected in a targeted manner, so that the required bed profile is achieved. In the special extreme case where the discharge speed is 0, only a thin but high strip of material is observed on the second continuous conveyor, for example green pellets, the profile of which is usually determined by the angle of repose of the material. From this it becomes clear that a slower movement of the unloading device results in a higher layer height than a faster movement. Thus, a convex profile will be achieved when the discharge device moves more slowly during the loading of material in the middle of the second continuous conveyor than in its edge regions.

A first approximation of the unloader speed profile to create the desired convex profiles h2, desired ( ^x ) on the second continuous conveyor can be calculated in a closed form that appears to fit a parabolic layer profile, or by sampling an arbitrary layer profile. This first approximation makes it possible to control the speed of movement of the unloading device, which can vary depending on the specific location in the direction of movement LA2 during loading of the material, and here it is not necessary to measure the actual state of the layer profile. Sampling can, for example, be implemented with the reference points of a pre-calculated velocity profile at continuous distances, for example, approximately every 5 or 10 cm, so that the pre-calculated velocity profile will be obtained as a vector ^ A2, pre-calculated ( ^x ) <which in in the case of a given width B2 of 4 m with 5 cm distances it contains 81 values, or in the case of 10 cm distances it contains 41 values. The first and last vector values are always the desired layer height at the edges of the second continuous conveyor. Assuming the second continuous conveyor is a conveyor belt having a horizontal bearing surface, the required layer height at the edges is always 0. When the conveyor belt contains rises in the edge area, then the required layer height in the edge area can also be> 0.

But due to the fact that due to the connection of continuous conveyors, additional variable disturbances can become important, such as, for example, homogenization of convex profiles by installing a roller screen as the third continuous conveyor (for sorting grains that are too large and / or too small) , a fully automated regulation of the profile ^ 4, desired ( ^x ) layer is required, which almost completely compensates for every deviation between the actual profile ^ 4, actuai ( ^x ) and the desired profile ^ 4, desired ( ^x ) on the fourth continuous conveyor, and that also completely compensates for optional disturbance variables. Therefore, in the regulating device, the desired profile ^ -4, desired W layer,

- 13 036991 duration τ _{Α2 of} movement of the unloader in the direction LA2 of movement, during which the material is loaded, and the pre-calculated profile ^ A2, pre-calculated (D) of the movement speed.

Preferably, these values will not be changed after the start of operation of the plant and the corresponding optimization measures, but rather will be kept constant during continuous operation. Each time the installation is restarted, for example after completion of maintenance, this saved data is always used again. When the unloader then loads the material during some transfer cycles onto the second continuous conveyor, shortly before the start of movement in the direction L _{A2 of the} movement, during which the material is loaded, each profile ^Y A2, new ( ^% ) of the speed of the unloading device is calculated according to the above formula ... For this, the actual profile ^ .actucuW on the fourth continuous conveyor is measured in the manner described above and stored.

It is possible to describe the actual profile using a piecewise-defined mathematical function, for example, using spline interpolation, but in general, however, the sampled shape has been shown to be better suited for general control and regulation mechanisms, while also being reasonably accurate.

Г (ν ')

For this, for example, the actual profile ^J on the fourth continuous conveyor is measured at discrete distances, for example, 5 or 10 cm across the width B _{4 of the} fourth continuous conveyor. The required profile ^ WesiredCO on the fourth continuous pipeline is sampled in the same way. Now the measured actual% profiles, actuaz ( ^x )> for which, for example, measurements were taken every 0.1 s and stored are averaged over the entire unloading cycle. In this example, therefore, 240 profiles are averaged over the entire travel cycle of the unloader at a periodic time of 24 seconds. This averaged actual profile, written as a vector, is then used in the above equation as actual (10

It has been shown that subtracting from this actual profile, written in vector form, the required profile, also written in vector form ^ .desired ( ^x ), and dividing the difference by the required height in the middle of the fourth continuous conveyor provides an advantage. Thus, a dimensionless deviation is obtained, which is negative when the local actual height is less than the local required height. But it is positive when the local actual height is greater than the local required height. Thus, usually the values of the dimensionless deviation, also written as a vector, are closer to 0 than to -1 or +1.

By multiplying this dimensionless deviation by the attenuation coefficient a, for which a value of <0.2 is preferably chosen, the values become smaller again. When the result is then added to the unit vector 1, values are close to 1. They are greater than 1 when the local actual height is greater than the local desired height, and less than 1 when the local actual height is less than the local required height. When then the result of this addition, written in vector form, is multiplied by the old profile ^r A2, oid ( ^x ) of the unloader speed, then the new speed v _A2 , _new (x) of the unloader movement will be higher than the old speed v _A2 , _old ( x) displacement when the local actual height was greater than the local required height.

This makes sense since, in the case of higher travel speeds, locally less material is fed from the discharge device onto the second continuous conveyor. Thus, it can be expected that this intervention of the regulator will result in a decrease in the local actual height and that it will thus be more closely aligned with the local required height. Conversely, the new travel speed v _A2 , _new (x) of the unloader will be lower than the old travel speed v _A2 , _old (x) when the local actual height was lower than the local required height. As a consequence, at this location, more material is fed from the unloading device onto the second continuous conveyor, so that the local actual height is increased and thus more aligned with the local required height. When there is no longer a difference between the local required height and the local actual height, then it is also no longer necessary to change the local unloading pulley speed. Then the expression in square brackets of the above formula is exactly 1.0. Thus, the new local movement speed v _A2 , _old (x) remains identical to the old local movement speed v _A2 , _old (x).

Finally, it is necessary to ensure that the duration t _{A2 of the} direction L _{A2 of} movement during loading of the material does not change by the target change in the speed profile, since otherwise this would lead to the described discrepancies between the speed of the second continuous conveyor and the discharge device, which would lead to periodically generated minima or peaks in the direction of the second continuous conveyor, or that would require adjusting the conveying speed v ₂ of the second continuous conveyor in each cycle of the unloader, which is undesirable. Therefore, the newly calculated velocity profile ^v A2, new ( ^x ) must be normalized:

rS ₂ 1,

-------------- ^J ° v _{A2 / new} (x) ^ A2, new, normedi ^) ^- VA2, newlM *? A2

The integral of the reciprocal of the path-dependent speed over the width B2 of the second continuous conveyor ensures the duration of the return travel of the unloader in the direction of travel LA2. When this duration becomes longer than the intended duration, which must be kept constant, t _A2 , then the rate ^r ^ W increases in accordance with the above equation, which again leads to an adjustment of the required duration tA2. Then, in a new unloading cycle, the material is loaded completely again without any adjusting interventions in this cycle, and then the actual profiles are stored again and used to control the subsequent unloading cycle in the manner described above. Thus, the deviation between the actual profile and the desired profile during discharge cycles are becoming smaller and smaller, so that after the initial setting only minimum required adjustments profile ^p n2 (X) speed. In general, this results in a regulating mechanism by which each arbitrary layer profile can be adjusted to bring it closer to the desired condition, provided that this desired condition is within a predetermined limit determined by the angle of repose.

In addition, it has been shown to be advantageous when the second continuous conveyor loads material onto the third continuous conveyor at a conveyance speed v ₃ . In this way, a profile can be formed on the second continuous conveyor without any additional action and can also be adjusted accordingly. This also corresponds to the general design of the plant, where the iron pellets are burned, whereby first the material from the granulating discs is collected on the first continuous conveyor, then the material from the first continuous conveyor is transferred by means of an unloading device to the second continuous conveyor, where profiles can be formed here, and then the material is transferred through the roller screen, which can be regarded as the third continuous conveyor, into the grate carts of the moving grate plant, the moving grate itself being considered the fourth continuous conveyor. Then, in the same way, the third continuous conveyor can transfer the material to the fourth continuous conveyor.

Likewise, material from the second continuous conveyor can be directly transferred to the fourth continuous conveyor. It is also preferred that both the third continuous conveyor and / or the fourth continuous conveyor comprise a measuring device.

Preferably, in this case, the measuring device determines the average height h ₃ , _actual * of the material layer M3 on the third continuous conveyor, and this determined actual value is compared with the predetermined desired target value h ₃ , _desired *. When the actual value h ₃ , actual * is lower than the predetermined desired value h ₃ , _desired *, it means that the transport speed v ₃ of the third continuous conveyor is too high and that this speed v ₃ must be reduced accordingly. Conversely, when the actual height h ₃ , _actual * of the bed exceeds the desired value h ₃ , _desired *, then the speed v _{3 of the} third continuous conveyor is too low, so that the stay of the material on this third continuous conveyor and therefore the average height of the bed becomes, respectively longer and longer than required. In both cases, the transport speed v ₃ of the third continuous conveyor is increased or decreased in a discrete or continuous manner until the average layer height h ₃ , _actual * again corresponds to the required value h ₃ , _desired *.

It is particularly advantageous when the measuring device above the fourth continuous conveyor can determine the actual profile of the material layer on this conveyor, and when the computer unit connected thereto can calculate the cross-sectional area of this material layer. In the sense of the invention, this cross-sectional area is defined in an orthogonal direction with respect to the conveying direction T ₄ of the fourth continuous conveyor. This calculated actual value Q _4, actual cross-sectional area based on the measurement, is compared with the desired value Q _{4, desired.} If there is a difference between the actual value Q ₄ , _actual and the required value Q ₄ , _desired , then in the sense of a regulatory intervention, the response can be one of the following two:

a) the material flow when the first continuous conveyor is loaded can be influenced such that the actual value of Q ₄ , _actual cross-sectional area is more closely aligned with the desired value of Q ₄ , _desired . When, for example, the calculated _actual cross-sectional area Q ₄ , _{actual is} less than the corresponding desired value Q ₄ , _desired , then more material is loaded when the first continuous conveyor is loaded.

- 15 036991

b) the conveyance speed v ₄ of the fourth continuous conveyor is adjusted such that the calculated actual cross-sectional area value Q4, _actual is more closely aligned with the desired value Q4, _desired . Thus, in the example mentioned in a), the conveyance speed v ₄ of the fourth continuous conveyor will decrease until the desired value Q4, _{desired is reached} .

For example, a deviation between the _actual cross-sectional area Q4, _actual cross-sectional area and the desired cross-sectional area Q4, desired cross-sectional area may occur when the grain size distribution of the bed material changes so that the grains become smaller and smaller, and when the third continuous conveyor is a roller screen, which sifts these smaller grains and therefore does not load them onto the fourth continuous conveyor. In addition, for the regulation (control device) described herein, it is important that the measuring device above the fourth continuous conveyor also determines the profile of the actual bed height of the material on the fourth continuous conveyor.

But it can also happen that the actual profile differs from the desired profile, but the _actual cross-sectional area Q4, _actual corresponds exactly to the required cross-sectional area Q4, _desired . In this case, it is not necessary to make the correction as described in points a) or b) above, but the regulatory intervention can only consist in manipulating the speed of the unloading device, which may vary depending on the specific location.

Conversely, it can also become a reality that the actual profile does indeed conform in shape to the desired profile, but the _actual cross-sectional area Q4, _actual is different from the desired cross-sectional area Q4, _desired . In such cases, the measured profile is usually too high or too low. In this case, the control intervention in relation to the velocity profile v _A2 (x) of the unloader does not help. Here, rather, it is first necessary that the _actual cross-sectional area Q4, _actual, be adjusted more closely to the desired cross-sectional value Q4, _desired .

It has been shown that it is advisable to maintain the last calculated velocity profile v _A2 , _new , n _ormed (x) of the unloader until the actual volumetric flow of the material bed equalizes in the range from 98 to 102% of the required volumetric flow of the material bed. Only then does the regulation of the profile start again. It has been shown that the same logic is advantageous in the case of starting a chain of continuous conveyors: in terms of control, the pre-calculated speed profile ^r A2, pre-caicuiated ( ^% ) is first used, and the cross-sectional area of the material layer profile on the fourth continuous conveyor is adjusted to the required value Q4, _desired in the manner described in either a) or b). Only when the actual value of the cross-sectional area is in the range from 98 to 102% of the required area Q4, _desired cross-section, then it is automatically switched to the above-described regulation of the profile by manipulating the velocity profile v _A2 (x) of the discharge device. The logic described in this paragraph can also respectively be used in the case of the first and second continuous conveyors, when there is a corresponding measuring device above this respective continuous conveyor.

In addition, it has been shown to be advantageous when the granular material contains iron. In particular, in the case of iron and steel production, large quantities of material are processed, and the example of transporting raw pellets from the pelletizing discs used for their production to combustion in a moving grate plant shows that this method is associated with decisive advantages, since only The modified loading of the grate carts of the moving grate can ensure that, on the one hand, the capacity of the grate carts is increased, and on the other hand, under the existing conditions in the plant, the used material is burned evenly and therefore a uniform product quality can be achieved at the end of the process.

In addition, the invention includes a device characterized by the features of claim 10. This device is preferably characterized by the features of at least one of claims 1 to 9 and the corresponding description.

Such a device contains one continuous conveyor, as well as at least two loading devices, which are designed in such a way that each loading device on the supporting surface of the continuous conveyor forms a continuous strip of granular material to be loaded. In the sense of the invention, these strips should be parallel to each other and should overlap each other so that a single layer of material is formed in the bearing surface, and the layer of material in cross-section, orthogonal to the bearing surface, has the shape of a trapezoid, while the parallel sides of the trapezoid also parallel to the bearing surface. In accordance with the present invention, the device is designed in such a way that at least one loading device can be moved laterally relative to the longitudinal direction of the continuous conveyor.

- 16 036991

A preferred embodiment of the invention is characterized in that at least one feeding device is a second continuous conveyor. This allows material to be transported from upstream process steps by means of a continuous conveyor, such as a roller screen or an additional conveyor belt, to the first continuous conveyor, so that this latter serves as a manifold for different material streams having the same or different compositions.

Preferably, in addition to the first loading device, there is at least one additional movable loading device on each side of the carrying surface of the continuous conveyor in the direction of its transport. Thus, on both sides of said first loaded strip, additional strips can be added which are inseparably added relative to the first loaded strip and thus represent an embodiment of the entire layer of material in the sense of the invention. In case of failure of only one loading device, the next loading device located on the same side and made with the possibility of movement can take its position.

Here it is also preferred that the structure of the first loading device is stationary and that it loads the first strip approximately in the middle of the continuous conveyor. When this first loading device fails, the strip in the middle can be loaded with every other mobile loading device, preferably a second or third loading device. Therefore, due to the higher costs in the case of the first loading device, the movable structure is not required.

However, in a particularly preferred embodiment, all downstream loaders are of a movable design, so that the above-described movement of the loader can be performed in each installation.

A particular advantage is when the device described above contains at least one measuring device that is capable of detecting flatness defects in the layer, expressed as minima or maxima in the lateral direction of the continuous conveyor. Such minimums or maxima are especially often created in the case of the described arrangement of the loading devices due to the fact that the overlap of adjacent strips is still not optimal. For example, a groove on the surface of the layer parallel to the edge of the continuous conveyor can be created due to the fact that the groove is located in the overlapping position of the two strips, the distance between the centers of the two strips being too large for the respective volume flows.

Such measuring devices can, for example, be ultrasonic sensors, which are positioned next to each other on a beam so that they cover the entire width of the continuous conveyor. Width in the sense of the invention is to be understood in an orthogonal direction with respect to the conveying direction of the continuous conveyor. Laser systems or simple deflection methods can also be used, such as, for example, one or more metal stripes, which are deflected more or less strongly by minima or maxima, which are then detected, for example, using rotary potentiometers, each of which is designed for one metal strip. In addition to measuring with ultrasonic sensors, radar sensors can also be used. Detection can also be carried out using an optical system, such as a camera, and then analyzed using computer analysis of the image.

A device in which, exclusively or in combination with the devices described so far, characterized by the features of at least one of claims 10 to 15 of the claims, and in which also the material transferred from the first to the second continuous conveyor also comprises a first and a second continuous conveyors, as well as an unloading device. The first continuous conveyor is designed to transport a layer M1 of material having an average width B1 and a conveying speed v1 to or onto a discharge device. The unloading device moves in the first direction of movement with a first movement speed v _A1 and in a second direction of movement opposite to the first, with a second movement speed vA2 across the width B _{2 of the} layer M _{2 of the} second continuous conveyor. This second continuous conveyor has a conveying speed v ₂ . In this case, the unloading device, in at least one direction of movement, continuously loads the material onto the second continuous conveyor. The object of the invention is that the device comprises a control device, partially connected to the control device, which regulates the speed v2 of the movement of the second continuous conveyor to a value according to the following equation:

₁ * 0.85 V ₁ * 1.15

Р ² __1__dx + Р ² __-__ dx ~ ^V2 ~ Р ² __-__ dx + Р ² __-__ dx ^J ° νΑ1 (χ) ^{αχ +} ^ νΑ2 (χΓ ^{Χ J} o WO ^J ° ν _Α2 (χΓ ^Χ

The following range is preferred

- 17 036991

B ₁ * 0.95 B ₁ * 1.05 f ⁵² __1__dx + f ^Bz __-__ dx ~ ^ ~ f ^Bz __-__ dx + f ^Bz __-__ dx ^J o vA1 ^ ^{ax +} ^ vA2 (x) Jo v _A1 ( x) ^{ax +} Jo v _A2 ^ ^ax and the following range is especially preferred

B ₁ * 0.98 V _g * 1.02 f ^Bz 1 dx + f ⁵² - dx ~ ^{2 -} ( ^Bz - dx + ( ^Bz - dx ^J o vA1 (x) ^{ax +} Jo vA2 (x) Jo v _A1 ( x) ^{ax +} Jo v _A2 (x)

Whenever one of the parameters v _A1 , v _A2 , B1 or B2 is changed, immediately and automatically the speed v _{2 of the} movement of the second continuous conveyor is adjusted according to the same formula.

In this way, continuous loading of the second continuous conveyor can be guaranteed, so that the additional material flow is relatively stationary and the corresponding subsequent processing steps are no longer subject to fluctuations in the loading of granular material.

Preferably, the first and / or second continuous conveyor is a conveyor belt or roller screen. The design of the conveyor belt is preferred because the conveyor belt is a particularly simple continuous conveyor. The roller screen has the advantage that in this way material having a size that is too large and / or too small (size in terms of diameter) can be discharged from the process. Combinations of two continuous conveyors are also possible, in which case, for example, a combination is possible in which at least one of the continuous conveyors consists partly of a conveyor belt and partly of a roller screen.

In addition, it is preferable that the unloading device is an unloading pulley. This is a particularly simple solution for the unloader, which can be moved, for example, by means of a double-acting hydraulic cylinder in combination with a hydraulic pump and appropriate hydraulic valves or a rack and pinion gear with a motor drive unit in combination with limit switches that change the direction of rotation of the drive or electrical motor with appropriate control in two directions.

But it is also within the scope of the invention when a turning belt is used as the unloading device, which loads material from the first continuous conveyor onto the second continuous conveyor. Therefore, it must be emphasized here again that the direction of movement in the sense of the invention does not necessarily mean a direct direction of movement, but only movement from one side of the second continuous conveyor to the opposite side and vice versa, while explicitly also, for example, parabolic loading of material by loading a pivoting belt is within the scope of the invention.

Another preferred embodiment of the invention comprises a measuring device that checks for minima and / or maxima on the material fed to the second continuous conveyor. Preferably, this measuring device is mounted on a second continuous conveyor. On the basis of the measurement results of this at least one measuring device, the transport speed of the second continuous conveyor can then be influenced by a regulating device, so that a constant flow of material to the second continuous conveyor is ensured. Compared to the above-described control, the control is a fine adjustment _{of the} transport speed v ₂ of the second continuous conveyor, which also compensates for disturbances such as time-varying angles of repose. Thus, v ₂ is the control variable, while the controlled process variable is the mass flow, in which the fluctuations over time are controlled so that they are practically zero.

In addition, it has been shown to be advantageous when the first measuring device checks the bed of material on the first continuous conveyor for minima and maxima in the lateral direction.

Such a device contains the first and second continuous conveyors, as well as an unloading device. The first continuous conveyor is designed to transport a layer of material having an average width B1 to or onto a discharge device. The unloading device is designed in such a way that it can move in the first direction L _{A1 of} movement at the speed of movement v _A1 and in the second direction L _{A2 of} movement opposite to the first, with the speed v _{A2 of} movement along the width B _{2 of the} material layer on the second continuous conveyor. The unloading device unloads the strips of material onto the second continuous conveyor in at least one direction of travel, preferably in direction L _{A2 of} travel.

In accordance with the present invention, the device comprises at least one control or regulating device (the latter preferably with a corresponding control unit), which, during loading, controls and / or regulates the varying speed of movement, preferably v _A2 (x), of the unloading device at the point along in at least one direction

- 18,036991 displacements, preferably in the direction L _{A2 of} displacement. This means that either the unloading device loads material in only one direction of movement, and during this loading of material, the local speed of movement changes, or the unloading device loads material in both directions of movement, and in at least one direction of movement the speed of movement changes locally. Thus, profiles in the x direction, preferably convex profiles, instead of a layer of material having a trapezoidal cross-section, can be formed on a second continuous conveyor, and thus, for example, the throughput of subsequent processing steps can be increased.

In addition, it has been shown to be advantageous when the first and / or second continuous conveyor is a conveyor belt or roller screen. The conveyor belt is a particularly simple and reliable form of a continuous conveyor and is thus preferred. The roller screen makes it possible to simultaneously remove particles that are too small or too large from the material layer and thus further homogenize the material layer. But the disadvantage of roller screens is that they partially homogenize the tuned profiles again. Combinations of two continuous conveyors are also possible, in which, for example, a combination is possible in which at least one of the continuous conveyors consists partly of a conveyor belt and partly of a roller screen.

However, an embodiment of the invention is preferred in the form in which both the first as well as the second continuous conveyor are conveyor belts, and that the second continuous conveyor is followed by a roller screen as a third continuous conveyor and a moving grate arrangement as a fourth continuous conveyor. ...

Furthermore, it is preferable that the unloading device is an unloading pulley that can be moved, for example, by means of a double-acting hydraulic cylinder in combination with a hydraulic pump and corresponding hydraulic valves or a rack and pinion gear with an engine drive unit in combination with limit switches that change direction rotation of the drive device or electric linear motor with appropriate control in two directions.

But it is also within the scope of the invention when a turning belt is used as the unloading device, which loads material from the first continuous conveyor onto the second continuous conveyor. Therefore, it must be emphasized here again that the direction of movement in the sense of the invention does not necessarily mean a direct direction of movement, but only movement from one side of the second continuous conveyor to the opposite side and back, while explicitly also, for example, loading material along an arc of a circle by loading a pivoting belt is within the scope of the invention.

Finally, it has also been shown to be advantageous when there is at least one measuring device that determines the profile of the material fed to the fourth continuous conveyor. Preferably, this measuring device is associated with the above described control mechanism. However, preferred is a device that comprises two measuring devices, namely a first device located above the first continuous conveyor, and a second device located after loading the material onto the fourth continuous conveyor.

Particularly preferred is a device that contains three measuring devices, namely one measuring device above each of the first, second and fourth continuous conveyors. Thus, a successful control of the deviation between the actual profile and the required profile on the fourth continuous conveyor can be achieved in the shortest possible time.

At least one such measuring device can be, for example, ultrasonic sensors, which are located next to each other on a beam so that they cover the entire width of the continuous conveyor. Width in the sense of the invention is to be understood in an orthogonal direction with respect to the conveying direction of the continuous conveyor. Laser systems or simple deflection methods can also be used, such as, for example, one or more metal stripes, which are deflected more or less strongly by minima or maxima, which are then detected, for example, using rotary potentiometers, each of which is designed for one metal strip. In addition to measuring with ultrasonic sensors, radar sensors can also be used. Detection can also be carried out using an optical system, such as a camera, and then analyzed using computer analysis of the image.

The invention is further explained with reference to the drawings. All features described and / or illustrated herein, by themselves or in arbitrary combination, form the subject matter of the invention, regardless of their summary in the claims or their backward references.

In the drawings:

fig. 1 shows an apparatus according to the present invention;

fig. 2a-d depict different general profiles depending on the operating state;

- 19 036991 fig. Over-c depict different general profiles depending on the operating state;

fig. 4 illustrates the interconnection, in accordance with the present invention, of a first continuous conveyor and a second continuous conveyor in the x-y direction;

fig. 5 illustrates the interconnection of the first and second continuous conveyors in the x-z direction;

fig. 6 illustrates the interconnection in accordance with the present invention of the first, second, third and fourth continuous conveyors in the xy, y direction, and FIG. 7 illustrates the interconnection of the first and second continuous conveyors in the x-z direction.

As shown, the continuous conveyor 10 may be a conventional conveyor belt that operates in a rotating manner with at least one drive device 12 so that the material to be conveyed is conveyed in the conveying direction T. Here the material is loaded onto the carrier surface 11. A roller screen is also possible, as well as all the aforementioned types of continuous conveyor.

Manufacturing units 21 through 27 are devices for performing an upstream process step. Here, for example, they can be granulating discs for the production of raw iron ore pellets. Beginning with these devices 21-27, additional continuous conveyors 31-37 lead to a continuous conveyor 10. They are designed in such a way that at their ends they load material onto a continuous conveyor 10. In its simplest form, this can be achieved by the fact that these continuous conveyors 31-37 are in the form of conveyor belts which, in the position of their respective discharge pulleys, discharge the material which is transported thereon onto the continuous conveyor 10. In essence, it is also possible not to use continuous conveyors 31-37, but to feed the material directly from devices 21-27 on a continuous conveyor 10. In principle, between devices 21-27 and continuous conveyors 31-37 it is also possible to install additional devices that further process the product of devices 21 to 27. For example, raw iron ore pellets from one of the granulating discs 21 to 27 can first be sieved with a roller screen (not shown) before they fall onto one of the continuous conveyors 31 through 37.

Here, in each embodiment of the invention, the mass flows of the individual strips do not have to be identical, that is, the cross-sectional areas of the individual strips may be different. Thus, it is not a requirement of the invention that all mass flows from all loaders are the same, but rather this is a special case.

The continuous conveyors 32-37 are designed so that they can be adjusted in the direction V of travel, and for this they comprise adjusting devices 42-47. Preferably, they can be adjusted by a drive device so that they can be directly moved by the primary control unit. But here it is also possible to provide a mechanical adjusting device that operates manually, for example a crank mechanism.

When, for example, the production device 23 fails, its lane closest to the lane of the device 21 is no longer added. When information is received that the device 23 has failed or when a minimum is found in the formed common layer that can be attributed to the device 23, then it is possible to move the production devices 25 and 27 and / or the corresponding continuous conveyors 35 and 37 through the adjusting devices 45 and 47 in such a way that the continuous conveyor 35 occupies the previous position of the continuous conveyor 33 and that the continuous conveyor 37 occupies the previous position of the continuous conveyor 35. Thus, the vacancy resulting from the failure of the device 23 is again filled, and the overall profile becomes thinner.

Preferably always when an electrical signal indicates a fault in one of the devices 21-27, the positions of the subsequent devices on the same side of the continuous conveyor are immediately changed to new positions at 17.5% of the conveying speed of the continuous conveyor 10. Thus, the fault caused by the failure of one of the devices 21 to 27, is almost completely eliminated within a few seconds. Thereafter, the fine tuning of the relocated loading devices is carried out, during which the minima and maxima on the surface of the layer are detected by the measuring device 50 and compensated by the slow movement of the loading devices, which previously moved relatively quickly. This is particularly advantageous when the travel speed during such fine tuning is 1.75% of the belt speed. Whenever peaks (hills) are found in the general profile in the transverse direction to the direction of transport T, the respective loading devices must move from the maximum width coordinate towards the edge of the continuous conveyor. Whenever a minimum (depression or groove) is found in the overall profile in the transverse direction to the transport direction T, the respective loading devices must move towards the middle of the continuous conveyor. Thus, the strips are again directly adjacent to each other, so that on the continuous conveyor 10, once again, a single uniform layer of material is created, having a common trapezoidal profile.

Preferably, a measuring device 50 is used to detect flatness defects in the formed common layer of material on the continuous conveyor 10. Detection after every second or third loading device is also particularly preferred. The advantage of a larger number of measuring devices is that the downtime in terms of the duration that elapses from the occurrence of a minimum or maximum until the detection by the measuring device is reduced. In the case of a distance of 20 m between the first and last loading devices and a travel speed of the continuous conveyor 10 of 0.5 m / s, the downtime may, for example, be 40 s. It is also possible that the measurement is carried out after each loading device 31-37.

FIG. 2a-2d show different general profiles of a layer of material on a continuous conveyor 10 in the transverse direction with respect to its conveying direction T in the case of the structure made in accordance with FIG. one.

FIG. 2a shows an ideal layer of material formed as a trapezoid on the carrying surface 11 of the continuous conveyor 10. Both parallel sides of the trapezoid are parallel to the carrying surface of the continuous conveyor. Each loading continuous conveyor 31-37 loads or adds its own strip S1-S7, which is here inseparably joined to the other in a parallel direction, so that this common trapezoidal profile is formed. FIG. 2 in this case, single lanes S1-S7 are assigned to loading continuous conveyors 31-37 based on the last digit of the number.

FIG. 2b shows the result of the failure of the production device 23 with the corresponding continuous conveyor 33, which has already been shown in FIG. 1, on which a minimum was obtained in the corresponding position, which corresponds to the absence of the entire band S3.

Then, in FIG. 2c shows how the total layer of material is changed again by moving the continuous conveyors 35 and 37 by means of adjusting devices 45 and 47, in accordance with the present invention, to the layer of material in the shape of a trapezoid, which now contains one less strip. In this case, the continuous conveyor 35 occupies the position that was previously the position of the continuous conveyor 33, and the continuous conveyor 37 occupies the position that was previously the continuous conveyor 35 position.

FIG. 2d shows how the overall profile changes again when the production device 23 is switched on again, so that in this position the material is loaded again through the continuous conveyor 33. Here the maximum is now formed, since the continuous conveyor 33 and the continuous conveyor 35 feed the material in the same position the bearing surface 11 of the continuous conveyor 10. Analysis of the cross-sectional area of the maximum with the measuring device 50 leads to the conclusion that here two complete strips were loaded in the same position. Once detected, for example by the measuring device 50, the continuous conveyors 35 and 37 are then moved by the adjusting devices 45 and 47 towards the edge of the continuous conveyor 10, so that they return to their original position, again forming a layer of material in accordance with FIG. 2a.

FIG. 3a again shows the same ideal overall profile as in FIG. 2a.

FIG. 3b, a small maximum can be seen in the overall profile, namely at the position where the strips S3 and S5 overlap each other. In this case, the discharge positions of the continuous conveyors 33 and 35 for the respectively supplied volume flows are too close to each other. When the measuring device 50 detects such a maximum, then the connected control device will change the positions of the continuous conveyors 35 and 37 by moving them towards the edge of the continuous conveyor 10, namely until the ideal profile of the entire layer, as shown in FIG. 3A will not be adjusted again.

FIG. 3c, however, a small minimum can be seen in the overall profile, namely at the position where the strips S2 and S4 overlap each other. Thus, here the distance between the discharge positions of the continuous conveyors 32 and 34 for the supplied volume flows is too great. When the measuring device 50 detects such a minimum, then the connected control device will change the positions of the continuous conveyors 34 and 36 in the direction of the middle of the continuous conveyor 10, namely until the ideal profile of the entire bed, as shown in FIG. 3A will not be adjusted again.

In a particularly preferred embodiment of the invention, the measuring device 50 is designed in such a way that the cross-sectional area of the entire layer can be easily and automatically calculated, even if the actual profile differs from the ideal profile. Particularly preferred is a connection with an analyzing device, which, especially in the case where the actual profile differs from the ideal profile, determines in which position the deviation is present and how large it is. For example, in the case of defects as shown in FIG. 2b and 2d, the analyzer would detect that the entire strip is missing or that the two strips were loaded in the same position.

- 21 036991

In the event of such defects, the analyzing device will transmit a signal to the drive units 45 and 47 to move at 17.5% of the transport speed of the continuous conveyor 10 in the direction each one wants. However, when the analyzing device detects small defects as shown in FIG. 3b or 3c, it will transmit a signal to the respective drive units to move at 1.75% of the conveying speed of the continuous conveyor 10. In this way, it is guaranteed that a large defect in the overall profile is quickly eliminated, and on the contrary, a small defect is corrected slowly in the sense of a thin adjustments to avoid overreaction of the regulator.

In an embodiment according to the present invention and according to FIG. 4, material (Mi with width B ₁ ) is fed through a first continuous conveyor 210 onto a second continuous conveyor 220. In the illustrated embodiment, the first continuous conveyor 210 is of a conveyor belt structure with at least one drive unit. The continuous conveyor 220 consists of a conveyor belt 221 and a roller screen 222, which has the advantage that particles that are too small and / or too large can be removed before proceeding with further processing steps. In this case, preferably, the conveyor belt 221 and the roller screen 222 have separate drive units. But likewise, any continuous conveyor design is also possible, made in accordance with the descriptions of the continuous conveyors mentioned in the introduction to the present description.

A continuous conveyor 210 transports material to or onto a discharge device 230. In the simplest case, this can be achieved by designing the unloading device as an unloading pulley around which a conveyor belt runs with a wrap angle of approximately 180 °.

The discharge device 230 moves in two directions of movement, namely the width of the layer of material M ₂ on the continuous conveyor 220 (B ₂ ), the width to be understood as being orthogonal with respect to the direction of movement. Thus, ideally, the discharge device 230 is moved from one side of the continuous conveyor 220 back to the other side. Here, in at least one direction of travel, it unloads the material. Typically this is the case where the unloading pulley moves in the second direction of travel, thus opposite to the direction T _{1 of} transport of the first continuous conveyor. This material (M ₂ with width B ₂ ) is then additionally transported from the second continuous conveyor 220 to the bearing surface of the second continuous conveyor 223.

Preferably, there is a measuring device 250 that determines the path of the flow of material on the continuous conveyor 220 and / or on its carrying surface. Such devices can be, for example, ultrasonic or radar probes, which are located next to each other on the beam so that they cover the entire area along the width of the second continuous conveyor. Laser systems or simple deflection techniques can also be used, such as, for example, one or more metal stripes that deflect more or less strongly due to minima or maxima, which are then detected again. In addition to measuring with ultrasonic sensors, radar sensors can also be used. Detection can also be carried out using an optical system, such as a camera, and then analyzed using computer analysis of the image.

When the time measurement device 250 detects repetitive minima or maxima height M2 material layer, then the velocity v ₂ transport second continuous conveyor 220, which is provided by the control device 240 can also be accurately set adjusting device 240, as required, so that the minima or the highs disappear.

FIG. 5 shows the same device in the xz direction. Here the material M ₁ is preferably in a stationary material flow conveyed on the carrier surface 211 of the first continuous conveyor 210 to the unloading pulley 230.

After the material M _{1 has been} unloaded from the discharge edge of the discharge pulley of the bearing surface 211 of the first continuous conveyor 210, it is guided in a known manner through the first tail pulley 212, the idler 214 with a corresponding tension weight 215 and the second tail pulley 213.

The unloading device 230 can be moved along the width B _{2 of the} second continuous conveyor, for example, as shown, by means of a hydraulic cylinder 231. Alternatively, an electromotive device or a device with two hydraulic cylinders is also possible.

In an embodiment according to the present invention and in accordance with FIG. 6, material is loaded by a first continuous conveyor 310 onto a second continuous conveyor 230, which in turn feeds material onto a third continuous conveyor 330, which in turn transfers material to a fourth continuous conveyor 340. In the illustrated embodiment, in the x- direction y the first continuous conveyor 310 is designed as a conveyor belt with at least one drive unit. The second continuous conveyor 320 is also a conveyor belt. The third continuous conveyor 330 is in the form of a roller screen, which has the advantage that particles that are too small and / or too large can be removed before proceeding with further processing steps. However, the fourth continuous conveyor 340 is in the form of a moving grate. But likewise, any continuous conveyor design is also possible, made in accordance with the descriptions of the continuous conveyors mentioned in the introduction to the present description.

A continuous conveyor 310 transports material to or onto a discharge device 316. In the simplest case, this can be achieved by constructing the unloading device as an unloading pulley, which redirects the conveyor belt of the first continuous conveyor 310, where the unloading device 316 can be moved across the entire width B2, and so it moves along the discharge area 60 of the carrying surface 321 of the second continuous conveyor 230 so that the material falls down from the unloading device 316 and is distributed over the entire width B2 of the second continuous conveyor 230. In general, the design of the unloading device 316 is such that it accumulates all the material conveyed by the first continuous conveyor 310 and transfers it to the second continuous conveyor 230 , but in an intermittent manner.

The discharge device 316 moves in two directions of movement, namely the width B2 of the layer of material M2 of the continuous conveyor 230, the width being understood in an orthogonal direction relative to the conveying direction T2 of the second continuous conveyor. Thus, ideally, the discharge device 16 is moved from one side of the continuous conveyor 230 back to the other side. Here it unloads material in at least one direction. This material is then transported by a continuous conveyor 230.

Preferably, a measuring device 351 is mounted above the end of the first continuous conveyor, which determines the shape and trajectory of the material flow on the first continuous conveyor 310 and / or its bearing surface. Such a device could, for example, be ultrasonic sensors that are located next to each other on a beam so that they cover the entire area along the width of the first continuous conveyor. Also, laser systems with movable mirrors or simple deflection techniques such as, for example, one or more metal stripes, which deflect more or less strongly due to minima or maxima, which are then detected again, for example, using an electric rotary potentiometer, can be used.

It is also possible to position the second measuring device 352 above the second continuous conveyor 320. When the measuring device 352 detects recurring minima or maxima, then the transport speed v ₂ of the second continuous conveyor 320, controlled by the control or regulating device 370, can also be controlled by it. when it is constructed like the regulator 370, but with an appropriate control unit so that the minimums or maxima disappear. In addition, it is also possible to position the third measuring device 353 above the third continuous conveyor.

It is especially preferred when the fourth measuring device 354 is located above the fourth continuous conveyor, especially preferably in a position immediately after loading the material. The material bed profile below this fourth measuring device is the most important controlled process variable. This profile should not only be kept constant over time by the 370 regulator, but also should be as close as possible to the required profile.

The fourth continuous conveyor 340 illustrates the design of a continuous conveyor, which, for example, consists of plates or lattice carts and thus contains R segments. Such a design is possible with any of the four continuous conveyors 310, 320, 330 and 340. In addition, , the continuous conveyor 340 for defining its bearing surface comprises side segments S, which are illustratively depicted for one segment R. In addition, this design is a possible design for any one of the four continuous conveyors 310, 320, 330 and 340.

FIG. 7 shows the same device in the x-z direction. Here, the material Mi is transported preferably in a stationary material flow on the bearing surface 311 of the first continuous conveyor 310 to the unloading pulley 316.

After unloading the material M1 from the edge of the unloading device 316, the bearing surface 311 is guided in a known manner through the first tail pulley 312, the idler 314 with a corresponding tension weight 315 and the second tail pulley 313.

The discharge device 316 can be moved across the width B2 of the layer M2 of the second continuous conveyor material, for example, as shown, by means of a hydraulic cylinder 317. Alternatively, an electromotive device or a device with two hydraulic cylinders is also possible. Here, the second continuous conveyor 320 is of a conveyor belt structure comprising a carrier leg 323 and a return leg 324.

List of item numbers:

continuous conveyor carrying surface drive unit

- 23 036991

21-27 production device

31-37 continuous conveyors

42-47 adjusting device measuring device

S1 - S7 strips of single continuous conveyors

D distance

T direction of transportation

V direction of movement

210 first continuous conveyor

211 bearing surface of the first continuous conveyor

212, 213 tail pulley

214 idler pulley

215 gravity weight

220 second continuous conveyor

221 conveyor belts

222 roller screen

223 bearing surface of the second continuous conveyor

230 unloader

231 hydraulic cylinder

240 control and / or regulating device

250 measuring device

310 first continuous conveyor

311, 321 bearing surface

312, 313 tail pulley

314 idler pulley

315 gravity weight

316 unloader

317 hydraulic cylinder

320 second continuous conveyor

323 bearing branch

324 reverse branch

330 third continuous conveyor

340 fourth continuous conveyor

351-354 measuring device

360 unloading area

370 control and regulation device

Mi layer of material on the first continuous conveyor

M2 layer of material on the second continuous conveyor

B1 material flow width on the first continuous conveyor

B ₂ width of material flow on the second continuous conveyor

₃ width of material flow on the third continuous conveyor

B4 material flow width on the fourth continuous conveyor

T1 transport direction of the first continuous conveyor

T2 direction of transportation of the second continuous conveyor

T3 transport direction of the third continuous conveyor

T ₄ transport direction of the fourth continuous conveyor v1 transport speed of the first continuous conveyor v2 transport speed of the second continuous conveyor v ₃ transport speed of the third continuous conveyor v ₄ transport speed of the fourth continuous conveyor

L _A1 first direction of travel of the unloader

L _A2 second direction of movement of the unloader v _A1 speed of movement of the unloader in the first direction of movement v _A2 speed of movement of the unloader in the second direction of movement

R segments of the fourth continuous conveyor

S lateral boundaries of the fourth continuous conveyor y * distance

Claims (12)

1. A method of loading a continuous conveyor with granular material, in which at least three loading devices are moved to each other in such a way that with each - 24 036991 of the loading device, a continuous strip of material is formed on the carrying surface of the continuous conveyor, and these strips are parallel to each other and superimposed on each other in such a way that one layer of material is formed on the carrying surface, which has a trapezoidal shape in cross section orthogonal to the bearing surface , while the parallel sides of the trapezoid are parallel to the bearing surface, characterized in that one or more measuring devices check the material layer for the presence of local minima and / or maxima, while, starting from the second loading device, the loading devices add their corresponding strip to the existing one strip on the side of the bearing surface, from which they are located, and with the help of the specified at least three loading devices form a continuous strip of material, and when the measuring device determines the minimum or maximum, move at least one loading device o, and the loading devices are located one after the other on both sides of the continuous conveyor in the direction of its transportation, while the loading devices, starting from the first loaded strip, add their strips in the position of strips from the 2nd to the nth to the already existing strip with on the side of the supporting surface on which they are located, where, when a minimum is detected, it is connected to the loading device (a), while the loading devices located downstream of this loading device (a) on this side are moved in such a way that from that moment on, they occupy positions n-1, and at each moment of time a layer of material is formed parallel to at least one edge of the bearing surface with a deviation of no more than 10 °. 2. A method according to claim 1, wherein said granular material contains iron. 3. A method of loading a continuous conveyor with granular material, in which at least one first continuous conveyor with a conveying direction T 1 and a conveying speed v1, loaded by the method according to claim 1 or 2, transports the material in the form of a layer of material having an average width B1 into unloading device or onto it, said unloading device being moved in the first direction of movement with the first movement speed v _A1 and in the second direction of movement opposite to the specified first direction, with the second movement speed v _A2 along the average width B _{2 of the} material layer of the second continuous conveyor, when wherein said unloading device continuously loads material in at least one direction of movement onto said second continuous conveyor, characterized in that said second continuous conveyor has a movement speed v ₂ for which the following is true: V _± * 0.85 V _± * 1.15 ^J ° vA1 (x) ^J 0 vA2 (x) ^J 0 vA1 (x) ^J o vA2 (x) 4. A method according to claim 3, characterized in that said first direction of movement of the unloading device and direction T _{1 of} transport of said first continuous conveyor coincide. 5. A method according to claim 3 or 4, characterized in that said first speed v _{A1 of} movement of the unloading device coincides with the speed v _{1 of} transport of said first continuous conveyor. 6. A method according to one of claims 3 to 5, characterized in that said first speed v _{A1 of} movement of the unloading device coincides with the second speed v _{A2 of} movement of the unloading device. 7. Method according to one of claims 3 to 6, characterized in that the layer of material on said first continuous conveyor has a trapezoidal cross-section orthogonal to the continuous conveyor, and the width B1 is the average width of this trapezoid. 8. A method according to one of claims 3 to 7, characterized in that said granular material contains iron. 9. Method according to one of claims 3 to 8, characterized in that the first measuring device checks the layer of material on said first continuous conveyor for minima and / or maxima. 10. A method according to one of claims 3-9, characterized in that the second measuring device checks the material fed to said second continuous conveyor for recurring minima and / or maxima. 11. A method according to claim 10, characterized in that upon detecting at least three periodically successive minima, the speed of said second continuous conveyor is reduced until minima no longer occur. 12. The method according to claim 10 or 11, characterized in that the decrease or increase in the transport speed v ₂ is no more than 2% in 15 seconds.