METHOD FOR OPERATING A FOOD PLANT AND FOOD PLANT OPERATED BY METHOD

Description

[0001] The invention relates to a method for operating a food supply system and to a food supply system operated by means of such a method.

[0002] A spinning mill comprises a multitude of individual spinning machines arranged in a production chain. One or more spinning machines supply the material for one or more downstream spinning machines. For example, a bale opener delivers fiber material to a cleaner, such as a foreign matter separator. The foreign matter separator delivers the (pre-)cleaned fibers to a mixer. The mixer delivers the mixed fibers to a fine cleaner. The fine cleaner delivers the finely cleaned fibers to several cards. The cards deliver fiber slivers to a comparatively smaller number of drawing machines. The drawing machines deliver drawn fiber slivers to, for example, a comparatively smaller number of spoolers. The spoolers deliver reels to a comparatively larger number of combing machines. The combing machines deliver combed and drawn fiber slivers to a comparatively smaller number of drawing machines.These lines, in turn, supply stretched fiber sliver, for example, to a flyer. The flyer then supplies roving to a spinning machine. The main challenge is to provide each spinning machine with enough material to process so that the entire system can operate as efficiently and without interruption as possible.

[0003] US Patent 2,983,325 A discloses a method in which, at periodic intervals in cyclical operation, a feeding device discharges measured quantities of fibrous material onto a feed conveyor. A mechanism automatically accelerates if the weighing box is filled too slowly.

[0004] A time-delay mechanism is incorporated that automatically accelerates a needle belt via a variable-speed motor drive if the belt has not supplied the weighing box with the desired amount of fiber within a predetermined time period. The timer starts automatically when a weighing box filling cycle begins. Once the weighing box is full, the timer stops. If the weighing box does not fill within a selected time period, the motor drive is accelerated to speed up the needle belt and thus ensure proper filling of the weighing box before the periodic emptying occurs.

[0005] From US patent 2 995 783 A, another machine is known that switches to high-speed operation shortly before the end of a predetermined time interval in order to fill the weighing pan with a predetermined amount of fiber material.

[0006] German patent DE 10 3005 040 399 A1 discloses a flake feeding system in which a spinning mill operator can input the production. A disadvantage is that the flake feeding system may be unable to feed the mixing belt in a timely manner when running continuously. This is primarily due to the fact that the air-fiber flow to each feeding machine is not as continuous as desired, meaning it does not always deliver the required number of flakes per unit of time. In this case, the mixing belt must be stopped until all feeding machines of the flake feeding system are filled. Furthermore, the production setting at each feeding machine is done manually, so there is no synchronization with the mixing belt.This leads to unwanted stop-and-go operation of the mixing belt, resulting in higher energy consumption for the entire system due to the frequent acceleration and deceleration of the belt, and thus higher costs. Furthermore, the overall production rate of the plant decreases, leading to production delays. Finally, this puts additional strain on the mechanics of the mixing belt system.

[0007] The purpose of the invention is to address the aforementioned disadvantages.

[0008] This problem is solved by the subject matter of claims 1 and 7.

[0009] Beneficial further training opportunities are listed in the sub-requirements.

[0010] According to the invention, a method for operating a feeding system is provided. The feeding system is equipped with a receiving device and at least one feeding device. The feeding device is designed in a known manner to cyclically weigh a predetermined quantity of fiber material and deliver it to the receiving device after weighing. The method comprises one cycle. During each cycle, in a first step, the quantity of fiber material belonging to the respective feeding device is weighed in that device. After a certain time period has elapsed, the cycle includes a second step of checking whether each feeding device has been able to weigh out and deliver the corresponding quantity of fiber material to the receiving device when the current cycle time has expired.With multiple feeding devices, their discharge times can differ, for example, due to varying quantities of fiber material to be weighed. Therefore, the test step takes the "slowest" feeding device into account. Otherwise, the entire process could stall, leading to the aforementioned stop-and-go operation. If the test shows that each feeding device is capable of correctly weighing and delivering the corresponding quantity of fiber material, the cycle includes a third step: delivering the corresponding quantity of fiber material from the respective feeding device to the receiving device. However, if the test shows that at least one feeding device is unable to correctly weigh and deliver the corresponding quantity of fiber material, the cycle includes a fourth step: increasing the operating speed of this at least one feeding device by a predetermined amount.This has the advantage that only the feeding device(s) that currently do not meet the required conditions regarding the speed of weighing and delivering the corresponding quantity of fiber material are affected by the operational change. And since the process only affects the feeding device(s) that do not currently meet the requirements, the receiving device does not need to be stopped.

[0011] The weighing process of the feeding device(s) includes a rapid filling phase and a slow filling phase. In the rapid filling phase, fiber material is transported into a receiving hopper of the respective feeding device at an initial filling speed. Simultaneously, this fiber material is weighed. Once a predetermined amount of pre-fill fiber material has been collected in the receiving hopper, and this amount is less than the predetermined total fiber material required, the slow filling phase begins. This phase involves a further transport of the fiber material into the receiving hopper at a second filling speed that is lower than the initial filling speed. Once the required amount of fiber material has been reached, the receiving hopper is brought to a standstill. This is known to be necessary so that the fiber material can accumulate in the receiving hopper and be completely delivered.The rapid filling phase serves to quickly reach the predetermined amount of pre-fill fiber material, and weighing does not need to be as precise. Precise weighing is achieved in the slow filling phase, thus ensuring reliable weighing.

[0012] Increasing the processing speed preferably involves shortening the weighing time at the respective feeding device. This does not affect other sub-processes of the weighing process, such as settling, which practically cannot be shortened without compromising the overall process.

[0013] Preferably, the second step includes checking whether each of the at least one feeding device has already weighed out the corresponding quantity of fiber material. This has the advantage that there is "room for improvement" when higher processing speeds are required. Furthermore, it ensures that the delivery of the weighed fiber material can always be carried out on time.

[0014] The cycle can include a fifth step. According to the invention, the fifth step is performed when the current cycle time is greater than the predetermined cycle time and it has been determined in the second step that each of the at least one feeding device has already weighed out the corresponding amount of fiber material. The fifth step comprises shortening the current cycle time of the receiving device by a predetermined amount. This amount is less than or equal to a minimum of the discharge times of all of the at least one feeding device and such that the new cycle time is greater than or equal to the predetermined cycle time. The fifth step has the advantage of allowing the feeding device(s) and the receiving device to be slowed down and accelerated again during the process, if necessary, once the causes of the slowdown no longer exist.One such cause could be, for example, if a feeding device receives too little fiber material per unit of time for weighing. In that case, the operating speed of both this feeding device and at least the receiving device would have to be reduced. If the amount of fiber material to be weighed increases again, the operating speed can be increased again.

[0015] In each of the aforementioned processes, the second step can include checking whether the weighing process of each of the at least one feeding device has progressed to the point that, after the current cycle time in the respective cycle has elapsed, the respective feeding device will have completed the weighing and delivery process. The rationale behind this check is that a temporary deceleration and subsequent acceleration of the receiving device may be sufficient to accomplish the weighing and delivery of the fiber material within the allotted time. This means that the receiving device does not need to be stopped. Thus, even in such an operating state, stop-and-go operation is largely avoided.

[0016] Preferably, a braking phase exists between these two phases, namely the rapid filling phase and the slow filling phase. In this phase, the filling speed of the receiving container is reduced from the first to the second filling speed according to a predetermined profile. This profile is determined, for example, by the desire to minimize mechanical stresses, particularly on the receiving container, during the speed reduction. Such stresses include, for example, vibrations of the receiving container, which can lead to uncontrolled fiber flight of the fiber material being collected within it.

[0017] The aforementioned reduction in weighing time can be achieved by varying the duration of at least one of the aforementioned weighing phases, preferably the fast and slow filling phases. Due to the aforementioned mechanical stresses, the braking phase preferably remains unaffected by the time reduction.

[0018] Each of the aforementioned methods may include a sixth step. The sixth step is executed if the second step reveals that at least one feeding device is unable to weigh and deliver the corresponding quantity of fiber material, and this feeding device is already operating at maximum speed. The sixth step involves signaling this status of the feeding device(s) to an external source. Alternatively or additionally, the sixth step includes a first subprocess. This subprocess involves transmitting the necessary remaining time to complete the weighing process for the feeding device(s) to a device controlling the receiving device. Subsequently, the current cycle time in the receiving device is modified based on a maximum of the transmitted remaining time.This results in the operating speed of the receiving device being reduced to a level at which each feeding device should be able to weigh its corresponding fiber material and deliver it to the receiving device. This means that the plant's operation does not have to be stopped; it is only (temporarily) slowed down. This also helps to avoid unwanted stop-and-go operation.

[0019] Preferably, each of the aforementioned cycles is repeated continuously. This results in a continuous fiber material processing process.

[0020] Each of the aforementioned methods can be used to operate a flake mixing plant. Such plants are known to serve the purpose of successively layering fiber material on top of each other on a transport section, preferably formed by a conveyor belt, using feeding devices or machines, and then feeding it to subsequent machines. The receiving device comprises a transport section. The transport section is configured to move the received fiber material in a predetermined direction. The at least one feeding device is designed to weigh out a predetermined quantity of fiber material (the corresponding quantity of fiber material) and, after weighing, to discharge or deposit it onto the transport section. The cycle includes a seventh step of moving the transport section in the direction of travel at a predetermined speed from a starting position relative to the cycle.The movement speed is essentially calculated from a predetermined cycle path and the current cycle time. The cycle path is the sum of the predetermined travel path and a predetermined drop path. The drop path represents the distance the transport section travels during the drop or placement process of the respective feeder. It therefore corresponds to the maximum distance the transport section travels during the drop of the feeder(s) located in the transport section's direction of movement. The second step of the respective cycle is executed when the transport section has traveled the predetermined path.If the second step shows that each feeding device has successfully weighed out the corresponding amount of fiber material, the cycle includes an eighth step: advancing the transport section at the predetermined speed. The third step involves dispensing the corresponding amount of fiber material once the transport section has completed the predetermined travel distance. If the second step shows that at least one feeding device has failed to successfully weigh out the corresponding amount of fiber material, a second subprocess is initiated. This subprocess includes a first step: decelerating the transport section to a lower speed.In a second step, the system waits until each feeding device has weighed and delivered the corresponding amount of fiber material, after the transport section has been accelerated back to the predetermined speed. In a third step, the transport section is then accelerated in the direction of travel to the predetermined speed. This subprocess also includes a fourth step: the discharge or deposit of the corresponding amount of fiber material once the transport section has reached the predetermined speed and / or a predetermined discharge position. In the latter case, the speed may not yet have reached its final value. This largely prevents stop-and-go operation.

[0021] The third step and / or the second sub-step can involve the discharge or depositing of the fiber material by each feeding device. This means that all feeding devices deliver their fiber material at the same time. This allows the operating speed of the receiving device to be adjusted without requiring one feeding device to be controlled differently in terms of timing than the other feeding device(s).

[0022] In a continuous cycle, the position of the transport section at the end of one cycle simultaneously represents the starting position of the transport section in the immediately following cycle. This enables a seamless transition between the individual cycles and thus a continuous production process, possibly with modified operating parameters.

[0023] After the discharge path has been traversed, the process may include an eighth step. This eighth step involves checking whether each feeding device has weighed out the corresponding amount of fiber material. If the check reveals that at least one feeding device has not yet completed its weighing, the second subprocess is started. This ensures that the entire system can adjust to avoid a stoppage.

[0024] If, in the second step, it is checked whether each feeding device has already weighed out the corresponding quantity of fiber material, the procedure for operating the flake mixing plant can include reducing the operating speed of the respective feeding device by a predetermined amount. This means that, particularly if a receiving device is running too slowly, i.e., if the current cycle time is longer than the predetermined cycle time, it can be (re)accelerated during processing. This allows the plant, for example, to be restarted from a temporary phase of relatively slow production.

[0025] The invention also provides a feeding system. This system is constructed and designed to be operated according to one of the aforementioned methods.

[0026] Preferably, this system represents the aforementioned flake mixing system. At least one feeding device comprises a weighing container with a filling barrier formed on a side facing away from the transport section. The filling barrier is designed, as is known, to close a filling opening of the weighing container in an activated state, thus preventing fibrous material from entering the weighing container. This state occurs when weighing (without stabilization) is complete. In a deactivation state, however, the filling barrier is designed to (re)open the filling opening. Furthermore, the weighing container has a discharge section formed on a side facing the transport section. The discharge section is designed, in a deactivation state, to close a discharge opening of the weighing container, thus preventing fibrous material located in the weighing container from falling out.In an activated state, the discharge opening of the weighing container is open and positioned at a distance from the transport section such that any fiber material in the weighing container falls onto the transport section when the discharge opening is open. Furthermore, the feeding device includes a weighing unit. The weighing unit is designed to determine the current weight of the fiber material held in the weighing container. The system is configured not only to determine the cycle time but also, based on the determined cycle time and the current speed and / or braking distance of the transport section, to determine whether the feeding device(s) are able to weigh the corresponding quantity of fiber material once the transport section has traveled the predetermined discharge distance.This ensures that the system is able to provide the fiber material in a timely manner, at least during temporarily slowed-down transport sections. This improves operational reliability.

[0027] Preferably, such a system has several feeding devices arranged one behind the other in the direction of travel of the transport section. Each pair of immediately adjacent feeding devices maintains a minimum distance from each other corresponding to the path traveled by the transport section during the discharge of at least one feeding device in the direction of travel. This ensures that the fiber material lands at the intended location on the transport section.

[0028] The feeding device can be selected or a combination of fiber opener, cleaner and / or mixing cleaner.

[0029] Further features and advantages of the invention will become apparent from the following description of preferred embodiments. These show: Figure 1 shows a part of a spinning mill in two views, Figure 2 shows a method for operating the spinning mill. Figure 1 , according to one embodiment of the invention, Figure 3 the weighing process of Figure 2 in greater detail, Figure 4 the braking process of Figure 2 in greater detail, Figure 5 the dropping process of Figure 2 in greater detail and Figure 6 the acceleration process of Figure 2 in greater detail.

[0030] Figure 1 shows a flake mixing plant 1 as an example or component of a spinning plant.

[0031] According to the perspective view in Figure 1aIn the example shown, there are two feeders 10. Each feeder 10 has an inlet 11 for an incoming fiber-air stream. This stream is opened in a known manner in a corresponding section 12. The fiber flakes opened in this way are fed to a corresponding weighing section 20. The weighing section 20 is located behind a front cover 24.

[0032] To the left of the feeders 10 is an additional box feeder 2, which also opens incoming fiber material and feeds it to an associated weighing section 20.

[0033] Below the three weighing sections 20, 20, 20 is a receiving section, also referred to as the receiving device 30. The receiving device 30 serves to transport fiber material discharged from the weighing sections 20 in the transport direction R to an outlet 32 ​​of the receiving device 30. The receiving device 30 is covered at its front side by covers 38. To the right of the last cover 38 in the transport direction R is a mixing opener 40, which mixes and opens the fiber material supplied by the feeders 2, 10 before feeding it to the outlet 32.

[0034] An operating terminal 31 is intended, preferably to operate the entire section of plant 1 shown here. However, it can also be intended, for example, to operate only the mixing opener 40.

[0035] Preferably all weighing sections 21 have the same width b.

[0036] Figure 1bshows a section of plant 1 in longitudinal section within the weighing sections 20, which are located below the in Figure 1a The feeders 10 shown are arranged. Each weighing section 20 has a weighing container 21 in a known manner, into which fiber flakes 4a fall. In the state shown, the fiber flakes 4a pass through an inlet section 23 of the weighing section 20, which is arranged on the left here. The inlet section 23 is formed, by way of example, by means of a closable opening in the top of the respective weighing container 21. The fiber flakes 4a fall onto a closed discharge opening of a discharge section 22, which faces the receiving device 30 and is thus located on the underside of the weighing container 21. This forms a layer of fiber material 4, formed by the flakes 4a.

[0037] Once the respective weighing container 21 is full, this discharge opening of the weighing container 21 is opened, as shown for the right weighing section 20. The fiber material (here designated with reference numeral 3) falls in the direction F onto a transport section, exemplified as a conveyor belt 33. As can be seen, there is already fiber material 4 on the conveyor belt 33, specifically on its section 33a facing the weighing sections 20 and 21, which originates from the left weighing section 20. This section 33a, and thus the fiber material 4 on it, is transported to the right in the direction R. Figure 1b The material is moved and compressed by means of a roller 36 arranged between the two weighing containers 21 shown here. Preferably, air is simultaneously forced out of this fiber material 4.

[0038] The fiber material 3 collected in the right-hand weighing container 21 falls in layers onto this fiber material 4. The resulting two-layered fiber material 3, 4 preferably passes through a further roller 36 and is thereby further compressed. The mixing opener 40 mixes the two fiber materials 3, 4 together in a known manner by means of rollers 41 and simultaneously opens them by means of the opening roller 42, preferably located on the right. As can also be seen, the fiber material falling in the direction of F has a certain distance a to the previously discharged pile of fiber material 3. The distance a is composed of the position of this pile in relation to the right-hand weighing container 21, the speed of the conveyor belt 33, and the time that the falling material 3 requires to reach the conveyor belt 33 or the fiber material 4 deposited on it. This time is also referred to as the discharge or delivery time.The discharge process preferably began when the left end of the pile was approximately in the area of ​​the right edge of the right weighing container 21. The travel distance for the transport section per cycle Z (explained in more detail later) is therefore composed of the width b and the respective distance between two weighing containers 21, or the maximum of the sum of the respective widths of all weighing containers 21, except for the last weighing container 21 in the transport direction R, and the distance to the next weighing container 21 in the transport direction T, as well as the width of the last weighing container 21.

[0039] The resulting fiber mixture is transported in the form of flakes through a shaft 37 towards outlet 32. The mixture is then fed back into the downstream machines of plant 1 in the form of flakes 5.

[0040] The conveyor belt 33 is preferably designed to run continuously around two deflection rollers 35, 35. On the side facing away from the winding containers 21, the conveyor belt 33 is preferably supported by freely rotatable rollers 34, which can also function as tension rollers. Alternatively or additionally, at least one of the deflection rollers 35 can also serve as a tension roller. The conveyor belt 33 is driven by one or more of the rollers 34, 35.

[0041] Figure 2 shows a method for the in Figure 1 As shown in Annex 1, after a start in step S1, a cycle Z is started for each device 2, 10 equipped with a weighing section 20. The cycle Z for a device 2, 10 is shown as an example and is indicated by a surrounding dashed line.

[0042] In a first step S10, the fiber material received in the respective weighing container 21 is weighed. The inlet section 23 specified above is open for this purpose.

[0043] In step S2, it is then checked whether the weighing process has finished. If this is not the case (no branch after step S2), the system jumps back to step S10. Otherwise (yes branch after step S2), this state is reported in a subsequent step S3 to a device, preferably controlling the receiving device 30.

[0044] In step S4, it is then checked whether the cycle is OK, i.e., whether the time provided for the entire cycle Z (= cycle time), reduced by the time required to deliver the fiber material, for example, to conveyor belt 33, has been essentially used up to complete the weighing process.

[0045] If this is the case (yes branch after step S4), a subsequent step S6 checks whether a ejection pulse has been emitted by the controller specified above. According to the invention, the ejection pulse is emitted when all devices 2, 10 have reported the end of the respective weighing process in step S3. However, it is also possible that only some of the devices 2, 10 have to emit this signal, because another part is not weighing or is only partially weighing in the current cycle Z. If such an ejection pulse has been emitted (yes branch after step S6), an ejection process is carried out in step S20. Otherwise (no branch after step S6), the process returns to step S6.

[0046] If cycle Z is not OK (no branch after step S4), a subsequent step S5 checks whether cycle Z was too short, i.e., whether the cycle time was too low. If this is not the case (no branch after step S5), a deceleration process is performed in a subsequent step S30. Otherwise (yes branch after step S5), an acceleration process is preferably performed in step S40. After both processes according to steps S30 and S40, the process jumps either to step S20, as shown here, or to step S6.

[0047] After the ejection process is complete, a subsequent step S7 preferably checks whether the entire process is finished, i.e., whether all cycles Z provided for in the production have been completed. If this is the case (yes branch after step S7), the process is completed in step S8. Otherwise (no branch after step S7), the process jumps back to step S10.

[0048] Figure 3 Figure 10 shows the weighing process in greater detail. This process preferably includes, as a first step S11, the opening of the inlet section 23. This allows any fiber material located on the weighing container 21 to fall into the respective weighing container 21. A so-called rapid phase then takes place in step S12.

[0049] In this phase, the associated weighing container 21 is filled with fiber material at an increased feed rate. The purpose of this is to fill the weighing container 21 with a specific quantity of fiber material (prefill fiber material quantity) in a relatively short time. The added fiber material is only roughly measured by weight. This means that the prefill fiber material quantity is less than the total quantity of fiber material ultimately intended for the respective cycle Z. In a subsequent step S13, it is checked whether the prefill fiber material quantity has been reached. If this is not the case (no branch after step S13), the process returns to step S13.

[0050] Otherwise (yes branch after step S13), a subsequent step S14 switches to a slow phase. In the slow phase, the weighing container 21 is filled with more fiber material at a lower filling rate. This allows for a more precise measurement of the amount of fiber material taken in. Consequently, the weight of the fiber material taken in is now measured more accurately.

[0051] In a subsequent step S15, it is checked whether the weighing container 21 is full, i.e., whether the weighing container 21 has received the amount of fiber material intended for the cycle. If this is not the case (no branch after step S15), the process returns to step S15. Otherwise (yes branch after step S15), the inlet section 23 is closed in a step S16. Then, or simultaneously, a so-called settling phase takes place in a step S17. During this phase, no further fiber material is added to the respective weighing container 21. This allows the weight of the amount of fiber material received in the respective weighing container 21 to be precisely determined. The weighing process is then completed according to step S10.

[0052] Figure 4This shows the deceleration process according to step S30 in greater detail. In a first step, S31, at least the end time for the next cycle Z is postponed, thus increasing the cycle time. This provides more time for the entire subsequent cycle Z. If the weighing process according to step S10 is complete after... Figure 3 Furthermore, in step S31, it may be provided that fixed times are specified instead of steps S13 and S15, and that at least one of these times is extended, so that it can be assumed that in the now new cycle time the corresponding device 2, 10 is able to have weighed the amount of fiber material in time for the next cycle Z.

[0053] In a subsequent step S32, the operating speed of the respective device 2, 10 is adjusted for the next cycle Z to the new end time and, if applicable, to the shifted switchover time(s) between the phases. For example, in the case of a feeder 10, this adjustment can affect the rotational speed of material transport rollers (not described further here). The material transport rollers rotate at a lower speed in the next cycle, thus reducing the mechanical load and wear.

[0054] Figure 5 This shows the discharge process according to step S20 in greater detail. In a first step S21, the respective outlet section 32 is opened so that fiber material can be discharged according to... Figure 1The discharge section can fall onto the transport section. In a subsequent step S22, it is checked whether the opening time has expired. If not (no branch after step S22), the process returns to step S22. Otherwise (yes branch after step S22), the discharge section 32 is closed in step S23, and the discharge process is complete.

[0055] Figure 6This shows the acceleration process according to step S40 in greater detail. In a first step, S41, it is checked whether the operating speed can be increased at all. This check is carried out, for example, by verifying whether the respective device 2, 10 is already operating at maximum speed. If the operating speed cannot be increased (no branch after step S41), this is reported to the aforementioned control unit in a subsequent step, S43, and the process is terminated. If the operating speed can be increased (yes branch after step S41), analogous to the deceleration process, at least the end time for the cycle time of the next cycle Z is brought forward. The operating speed of device 2, 10 is then adjusted to the new end time of the next cycle Z. In practice, step S32 is thus carried out according to Figure 4 The process is repeated. Afterwards, the acceleration process is completed according to step S40.

[0056] The invention is not limited to the aforementioned embodiment.

[0057] In the "yes" branch before step S30, it may be possible to check whether the cycle time is sufficient to fill the relevant weighing container 21, i.e., whether the cycle time is sufficient to complete the weighing process without considering the discharge time. Alternatively or additionally, the relevant device 2, 10 can transmit to the control unit a remaining time that the device 2, 10 requires to fill the associated weighing container 21 and discharge the fiber material. In both cases, the control unit can reduce the speed of the transport section and preferably increase it back to the original speed before the maximum of the reported remaining time(s) has elapsed, so that all devices 2, 10 can discharge their material onto the transport section according to the production specifications.

[0058] Alternatively, at a specific time in the current cycle Z, before the transport section reaches a respective drop-off position, the devices 2, 10 preferably issue a pre-signal based on empirical data, if they can ensure the filling of the associated weighing container 21. If one of the pre-signals is missing, the control device preferably slows the transport section down to 0 in the extreme case when the latter drop-off position is reached, provided at least one pre-signal is still missing.

[0059] Furthermore, it may be provided that the control device reduces the speed of the transport section for at least the next cycle Z if one of the devices 2, 10 has issued a message according to step S43.

[0060] Step S30 can be modified such that a message is first sent to the control unit containing the time required to complete the respective weighing process, preferably including the discharge time. The control unit can then increase the transport speed accordingly for the next cycle Z, if it was previously reduced. Furthermore, the control unit can inform the reporting device 2, 10 whether and, if so, to what extent it should reduce its operating speed for the next cycle Z. Alternatively, the control unit can simply transmit the new cycle time, and the reporting device 2, 10 determines the operating speed for the next cycle Z itself.

[0061] The acceleration process according to step S40 can be omitted. This means that step S4 can be replaced by step S5. This eliminates a decision step in the procedure according to Figure 2 saved.

[0062] Between the in Figure 3 In the phases shown according to steps S12 and S13, a braking phase can be provided during the transition to the slow-down phase. During the braking phase, the operating speed of the respective device 2, 10 is reduced in a manner that minimizes mechanical stress, for example, on the weighing container 21. Such mechanical stresses can be vibrations resulting from the braking of the exemplary material transport rollers. Preferably, the braking is carried out according to a predetermined braking curve.

[0063] Does the procedure demonstrate the in Figure 3In the phases shown, during the deceleration process according to step S30, it may be possible to shift the switching point between the fast and slow phases forward in time. This shortens the fast phase and lengthens the slow phase. This also has a positive effect on the mechanical stress of the affected device 2, 10. If the braking phase described above is also provided, it can be lengthened in addition to or as an alternative to the slow phase by shifting the switching point(s) between the fast and braking phases or between the braking and slow phases for the next cycle Z in time.

[0064] Similarly, in the acceleration process according to step S40, the switching point between the fast and slow phases can be shifted later in time. This lengthens the fast phase and shortens the slow phase. Shortening the slow phase is particularly useful if the slow phase has been lengthened beforehand. If the braking phase described above is also included, it can be shortened in addition to or as an alternative to the slow phase by shifting the switching point(s) between the fast and braking phases or between the braking and slow phases in cycle Z.

[0065] The operating speed can be increased or decreased using predefined values. Alternatively, it is possible to determine the operating speed required to fully utilize the cycle time.

[0066] In addition to taking mechanical stress into account, the process, and therefore every system operated with it, is very gentle on fibers.

[0067] As a result, the invention provides an effective method according to which a production plant or line in the spinning mill can automatically adapt to given and changing conditions, whereby the disadvantageous stop-and-go operation can be largely avoided. Reference symbol list

[0068] 1Flake mixing plant 2Box feeder 3, 4Fiber material 4a, 5Flake 10. Diners 11. Entrance 12. Opening section 20 Weighing section 21 Weighing box 22 Drop section 23 Inlet section 24 Cover 30 Acceptance device 31 Control panel 32 Outlet 33 Conveyor belt 33aTrum 34 Support roller 35 Deflection roller 36 Roller 37 Shaft 38 Cover 40 Mixing opener 41 Roller 42 Opening roller aDistance bWidth F Falling direction R Transport direction Z Cycle Si; i e NSchritt

Claims

1. Method • for operating a feeding system (1) with - a receiving device (30) to be fed and - at least one feeding device (2, 10), designed to weigh out, in cycles, a predetermined quantity of fibre material, also referred to as the associated quantity of fibre material, · and · to deliver it to the receiving device (30) after weighing, and • comprising a cycle (Z) with - a first step (S10) of weighing the associated quantity of fibre material in the respective one of the at least one feeding device (2, 10), and - when the first step (S10) has been completed, a second step of checking whether each respective one of the at least one feeding device (2, 10) is capable of having weighed and delivered the corresponding amount of fibre material to the receiving device (30) when the current cycle time has elapsed, and - if the second step shows that each of the at least one feeding device (2, 10) is able to weigh and deliver the corresponding amount of fibre material accordingly, a third step (S20) of delivering the corresponding amount of fibre material to the receiving device (30), and - if the second step results in at least one of the at least one feeding device (2, 10) being unable to weigh and deliver the corresponding amount of fibre material accordingly, a fourth step (S40) of increasing a working speed of this at least one feeding device (2, 10) by a predetermined amount, - characterised in that the step (S10) of weighing the at least one feeding device (2, 10) includes · a rapid filling phase (S12) comprising simultaneously · transporting fibre material into a container (21) of the respective feeding device (2, 10) at a first filling speed, and · weighing the fibre material received in the container (21), · upon reaching a predetermined pre-fill fibre material quantity in the container that is less than the associated fibre material quantity, a slow filling phase (S24) comprising continuing to transport the fibre material into the container (21) at a second filling speed that is lower than the first filling speed, and upon reaching the predetermined amount of fibre material, a stabilisation phase with respect to the container (21).

2. Method according to claim1 , wherein the step (S40) of increasing the working speed comprises shortening the time for weighing.

3. Method according to one of claims 1 or 2, comprising a braking phase which • which is performed between the fast filling phase (S12) and the slow filling phase (S24), and • in which the filling speed is reduced from the first to the second filling speed according to a predetermined progression.

4. Method according to claim 2, wherein the shortening of the weighing time is achieved by varying the duration of at least one of the weighing phases.

5. Method according to one of the preceding claims, further comprising a sixth step (S43) • performed when - the second step results in at least one of the at least one feeding device (2, 10) being unable to have weighed and delivered the corresponding amount of fibre material, and - the at least one feeding device (2, 10) is operating at maximum working speed, and • comprising - signalling this state of the at least one feeding device (2, 10) externally in relation to the at least one feeding device (2, 10) and / or - a first sub-process comprising · transmitting (S43) a necessary remaining time for completing the weighing for the at least one feeding device (2, 10) to a device (31) controlling the receiving device (30), and · changing the current cycle time in the receiving device (30) based on a maximum of the transmitted at least one remaining time.

6. Method according to one of the preceding claims, wherein the cycle (Z) is repeated continuously.

7. Feeding system (1), constructed and designed to be operated according to a method of the preceding claims, wherein • the receiving device (30) comprises a transport section (33) designed to move received fibre material in a predetermined direction of movement (R), • the at least one feeding device (2, 10) is designed to weigh a predetermined amount of fibre material - and - after weighing, to drop or deposit it onto the transport section (33), • at least one of the at least one feeding device (2, 10) - has a weighing container (21) which ∘ forms the respective container (21), ∘ has a filling barrier formed on a side facing away from the transport section (33), designed ◊ in an activated state, to close a filling opening (23) of the weighing container (21) so that fibrous material is prevented from entering the weighing container (21), and ◊ in a deactivated state, opens the filling opening (23), ∘ has a discharge section formed on a side facing the transport section (33), designed ◊ in a deactivated state, closing a discharge opening (22) of the weighing container (21) so that fibre material located in the weighing container (21) is prevented from falling out of the weighing container (21), and ◊ in an activated state, to open the discharge opening (22) of the weighing container (21), and ∘ the arrangement is such that fibre material located in the weighing container falls onto the transport section (33) when the discharge opening (22) is open, and · has a weighing device (20) designed to determine the current weight of the fibre material contained in the weighing container (21), and • the feeding system (1) is designed - to determine the time for a cycle (Z) - on the basis of the determined cycle time and the current movement speed of the transport section (33) and / or the current braking distance of the transport section (33), to determine whether the feeding device (2, 10) is capable of weighing the corresponding amount of fibre material when the transport section (33) has travelled the predetermined drop path (a).

8. Feeding system (1) according to claim 7, • comprising a plurality of feeding devices (2, 10) arranged one behind the other in the direction of movement (R) of the transport section (33), • wherein each pair of immediately adjacent feeding devices (2, 10) has a minimum distance (a) between them, which corresponds to the drop path (a) with respect to the feeding device (2, 10) directly upstream in the transport direction (R).