Method for gravimetrically measuring the fill level of a spinning preparation machine, and spinning preparation machine
Patent Information
- Application Number
- IN202417064953
- Authority / Receiving Office
- IN · IN
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-03-18
- Filing Date
- 2024-08-28
- Publication Date
- 2026-09-21
- Estimated Expiration
- 2043-03-13
Abstract
Description
[0001] Title: Method for gravimetric level measurement of a spinning preparation machine and spinning preparation machine
[0002] Description
[0003] The present invention relates to a method for gravimetric fill level measurement of a spinning preparation machine that can be filled with fiber flakes. The spinning preparation machine comprises a plurality of adjacently arranged filling chutes, a feeding channel arranged above the filling chutes, which is connected on the inlet side to a central fiber flake inlet and has a bottom opening on the outlet side for each filling chute, a withdrawal device arranged below the filling chutes, which is connected on the inlet side to the filling chutes and on the outlet side to a central fiber flake outlet, and a weighing device with a signal connection to the control unit. Furthermore, the present invention relates to such a spinning preparation machine.
[0004] EP 3 587 631 A1 discloses a spinning preparation machine for processing fiber flakes, the machine frame of which is mounted on a foundation at at least four support points. Between the machine frame and the foundation, at least one load cell is provided for measuring the fill level of a fiber flake-fillable storage unit of the spinning preparation machine.
[0005] US2004255429 discloses a fiber dosing device for introducing fibers into concrete. The device comprises a frame to support the fiber dispensing device. Several load cells are mounted between the frame and a conveyor housing of the fiber dosing device.
[0006] Using a spinning preparation machine mounted on load cells, the filling weight of the fiber flakes can be precisely determined by knowing its empty weight. However, knowing the filling weight is not always sufficient to prevent individual filling chutes from running dry in spinning preparation machines with multiple filling chutes, as the fiber flakes can be distributed very differently across the individual filling chutes. As soon as one of the filling chutes runs dry, this impacts the production of the spinning preparation machine.
[0007] The object of the present invention is to provide a method for gravimetric level measurement of a spinning preparation machine, with which more uniform production can be achieved. Furthermore, the object of the present invention is to provide a spinning preparation machine that enables more uniform production. This object is achieved by a method of the type mentioned above in that the spinning preparation machine has several closure members arranged in the feed channel, which are adjustable by means of actuators, and a control unit configured to control the actuators for filling the filling chutes with the fiber flakes in such a way that, due to the setting positions of the closure members, only one of the bottom openings is connected to the central fiber flake inlet at a time. The method comprises the following steps:
[0008] 1) Measuring a change in a weight force using the weighing device in a defined time interval during a filling and / or emptying process;
[0009] 2) Calculating a change in the filling weight of the filling shafts by the control unit from the change in the weight force in the defined time interval;
[0010] 3) Calculating the filling levels of the filling shafts by the control unit, whereby the change in the filling weight is distributed to the at least one filling shaft that was connected to the fiber flake inlet in the defined time interval due to the setting positions of the closure elements:
[0011] An advantage is that the control unit controls the actuators and thus knows the positions of the closure elements. This allows the control unit to take into account, when calculating fill levels, which of the filling chutes was connected to the fiber flake inlet and for how long during the defined time interval. The weighing device also provides the control unit with information about how the weight force has changed during the time interval. Accordingly, the control unit can proportionally allocate the incoming quantity of fiber flakes, or the incoming weight, to the individual filling chutes, taking into account the information from the positions of the closure elements. In this way, the control unit can calculate the fill level of each filling chute.
[0012] During the filling process, a feed is made so that at least one of the filling chutes is filled with fiber flakes. Furthermore, the extraction device is stopped during the filling process, so that no fiber flakes are extracted from the filling chutes. During the emptying process, no feed is made, and the extraction device extracts the fiber flakes from the filling chutes. During the filling and emptying process, a feed is made, and the extraction device extracts fiber flakes from the filling chutes.
[0013] The weighing device measures a weight force from which a total weight can be calculated. The total weight consists of an empty weight and a filled weight. Because the weighing device is arranged in the force flow between the filling chutes and the stationary floor, the total weight does not have to correspond to the entire mass of the spinning preparation machine. In particular, the change in the weight force corresponds to the difference between the weight force measured at a starting point of the time interval and the weight force measured at an end point of the time interval. The change in the weight force thus has the same physical unit as the weight force. The weighing device and / or the control unit can convert or display the force value, preferably in kilograms.Similarly, the change in fill weight can correspond to the difference between the fill weight at the start point of the time interval and the fill weight at the end point of the time interval. The change in fill weight thus has the same physical unit as the fill weight, namely kilograms. The fill weight corresponds to the difference between the weight measured by the weighing device and the empty or tare weight, which can be stored in the control unit. The latter occurs when the filling chutes are empty or there are no fiber flakes in the spinning preparation machine. The empty weight can be measured using the weighing device or stored as a predefined value in the control unit.
[0014] The mass of the fiber flakes is thus used to calculate the fill level. This offers the following advantages over, for example, a height measurement, which can be carried out using light barriers arranged in the filling chutes: direct comparability with other information from tests or measuring systems in the spinning mill (e.g., the bale weight set up in the bale inspection for the bale opener); independence from material compression in the filling chutes by compressed air or fill weight; independence from changing material properties, such as packing density; independence from material distribution in the filling chute. The fill levels can be given in kilograms. This means that the fill level of the respective filling chute can indicate the quantity of fiber flakes in the respective filling chute in kilograms.This is advantageous because it allows a minimum value, i.e., a minimum fill level, and / or a maximum value, i.e., a maximum fill level, to be easily specified. This is particularly useful when the spinning preparation machine is to process different materials consecutively, for example, initially cotton fiber flakes and, after a material change, fiber flakes made of mixed fibers, which may include recycled fibers, for example. The values can be stored in the control unit or can be set or changed by an operator of the spinning preparation machine.
[0015] Furthermore, it can be provided that the aforementioned method steps 1) - 3) are repeated during the filling and / or emptying process. In particular, method steps 1) - 3) are repeated continuously. This means that the current fill levels are always known. The time interval can, for example, be 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds or even more than 5 seconds or even less than 1 second. The time interval is preferably in a range between 1 second and 10 seconds. To further optimize the calculation of the fill levels, it can be provided that the withdrawal device has a pair of feed rollers for each filling chute, wherein the control unit takes into account a feed roller speed of the feed roller pairs for calculating the fill levels. This makes it possible to precisely determine the weight of fiber flakes leaving the filling chutes in the respective time interval.For the respective time interval, the incoming weight can be determined by calculating the difference between the change in the filling weight and the outgoing weight. This increases the accuracy of the calculated fill level values. The status of the feed rollers is also recorded by the control unit. This can provide information as to whether the feed rollers are rotating or stationary. When the feed rollers are rotating, the filling chutes are emptied. When the feed rollers are stationary, no fiber flakes are drawn from the filling chutes. The feed rollers are preferably coupled to a common drive. Two of the feed rollers can be arranged in each filling chute. A separate drive can also be provided for each filling chute, driving the feed rollers of the respective filling chute. The rollers of the feed roller pairs are preferably driven at the same speed.In this way, the fiber flakes are removed from all feed chutes simultaneously, ensuring better mixing of the fiber flakes in the mixing channel. Furthermore, the drive train that drives all feed roller pairs is simpler in design. However, it is also possible, in principle, for each feed roller pair to be driven individually.
[0016] In particular, the control unit calculates the production of the spinning preparation machine based on the change in weight force, which is measured by the weighing device during a time window in which the hoppers are not being fed. Production indicates the weight of the quantity of fiber flakes per unit of time output from the spinning preparation machine. Production is typically expressed in kilograms per hour.
[0017] Tests have shown that production remains constant at fill levels where the individual filling shafts are filled between approximately 30 percent and 100 percent of the maximum fill level. Using the method according to the invention, which calculates the fill levels of the individual filling shafts, the filling shafts can be filled in a targeted manner. This prevents the individual filling shafts from running dry or the fill level from falling below the specified minimum value, which could be, for example, 40 percent of the maximum fill level.
[0018] To optimize the control of the entire spinning preparation process, the total fill level of the spinning preparation machine can be used, for example, together with the carding machine's output mass flow, to calculate maintenance windows, calculate changeover times between lines, and provide added value / security for the customer. In particular, the total fill level corresponds to the fill weight. This is particularly advantageous when the spinning preparation machine is designed as a mixer, especially a shaft mixer.
[0019] Further information obtained from the spinning preparation machine or available to the control unit, which can be used to further optimize the fill level measurement, can include, for example, pressure values from pressure measurements. The limit state, which refers to 100 percent filling of the respective filling chute, can be determined via the measured differential pressure between the feed and exhaust ports and can be checked by light barrier signals from light barriers, light sensors, etc., located in the filling chutes.
[0020] A further solution to the above-mentioned problem consists in a spinning preparation machine for processing fiber flakes, wherein the spinning preparation machine can be set up or is set up on a stationary floor and has several filling chutes arranged next to one another, a feeding channel arranged above the filling chutes, which is connected on the inlet side to a central fiber flake inlet and has a bottom opening for each filling chute on the outlet side, several closure elements arranged in the feeding channel, which are adjustable by means of actuators, a control unit which is configured to control the actuators for filling the filling chutes with the fiber flakes in such a way that, due to the setting positions of the closure elements, only one of the bottom openings is connected to the central fiber flake inlet at a time, and a take-off device arranged below the filling chutes,which is connected on the inlet side to the filling chutes and on the outlet side to a central fiber flake outlet. The spinning preparation machine is configured to carry out the above-described method and has the weighing device, which is signal-connected to the control unit and arranged in the power flow between the filling chutes and the stationary floor. The spinning preparation machine according to the invention results in the same advantages as those described in connection with the method according to the invention, so that reference is made here for short to the above description. It is understood that all of the aforementioned embodiments of the method are transferable to the spinning preparation machine and vice versa.
[0021] The closure members can be designed, in particular, as pivotable flaps, rotary slide valves, etc., which can be arranged in the feed channel. In particular, each closure member can be transferred to at least two of the setting positions. In a closed position, the respective closure member blocks the bottom opening in the feed channel assigned to the respective closure member, so that the filling chute adjoining the assigned bottom opening cannot be filled. In an open position, the respective closure member releases the bottom opening assigned to the respective closure member and enables the connected filling chute to be filled. The feed channel is blocked downstream of the now released bottom opening by the closure member in the open position. Due to this arrangement of the closure members, the last bottom opening in the feed channel in the feeding direction does not require a closure member.In other words, it is sufficient if (n-1) closure devices are provided for (n) bottom openings. As a result, only one of the bottom openings can be connected to the central fiber flake inlet at a time. Preferably, filling multiple filling chutes simultaneously is not possible.
[0022] The spinning preparation machine can, for example, be a fiber mixer designed as a shaft mixer. This can have several filling shafts arranged side by side or one behind the other in a feeding direction. The fiber flakes can be fed into the individual filling shafts via the feeding channel running above the filling shafts. The fiber flakes can be transported pneumatically, for example by means of one or more fans connected to the feeding channel. The closing element, for example a flap, in particular a rotary valve, can be arranged in the feeding channel for each filling shaft, whereby the closing elements can be opened and closed via the control unit. For this purpose, each closing element can interact with the respective actuator, which can be coupled to the control unit.Furthermore, the spinning preparation machine can have a take-off device consisting of rollers on the undersides of the filling chutes to empty the filling chutes. All filling chutes can be emptied simultaneously. The take-off device can comprise the intake rollers and downstream opening rollers in a conventional manner. An exhaust system, operating, for example, with a fresh air supply, can be connected below the take-off device to transport the mixed fiber flakes to the next processing machine, in particular another spinning preparation machine.
[0023] In particular, the spinning preparation machine has at least three and preferably at least four support points for installation on a stationary floor. In particular, the spinning preparation machine has a substructure and a machine frame, wherein the machine frame is supported relative to the stationary floor by means of the substructure. In order to be able to align the machine frame relative to the floor, the substructure can in particular have height-adjustable support feet. The filling chutes can be attached to the machine frame. For reliable fill level measurement, the mass is to be determined according to the invention by means of a gravimetric measurement by the weighing device, which preferably comprises several load cells. Due to the design of the spinning preparation machine, a measurement of the entire spinning preparation machine may be appropriate.When designed as a shaft mixer, a shaft-by-shaft measurement is also possible in principle, but a measurement of the entire spinning preparation machine with calculation of the individual shaft fillings or filling levels is preferred.
[0024] The load cells can be designed, for example, as shear beam load cells. In particular, the base body of such a load cell is designed as a spring element and is made of a metal that deforms under the application of force and returns to its original state when the force is removed. This defined deformation can be recorded via a strain gauge attached to the base body and converted into an electrical signal.
[0025] Furthermore, the simplest load cells can also include strain gauges, which can be mounted directly on the supporting supports of the substructure of the spinning preparation machine. Filling or emptying the filling chutes creates a mechanical load on the substructure, which causes material deformation, for example, in the support feet, and can be detected by the load cells.
[0026] In particular, the spinning preparation machine has at least four of the support points for installation on a stationary floor, wherein the weighing device has a plurality of load cells which are attached only to a subset of the support points, wherein the support points equipped with the load cells lie on an imaginary connecting line which is aligned parallel to a main axis of the spinning preparation machine.
[0027] According to one embodiment, the load cells can be arranged between the machine frame and the stationary floor.
[0028] According to a further embodiment, the spinning preparation machine can have a decoupling device with at least four support points for installation on a stationary floor, wherein the machine frame and the decoupling device are structurally separated from one another, and the load cells are arranged between the decoupling device and the machine frame.
[0029] To eliminate disturbances that could affect the measuring accuracy of the weighing device, pipes for feeding and extraction, such as a fiber tuft inlet and / or a fiber tuft outlet, through which the spinning preparation machine is connected to upstream or downstream spinning preparation machines, can be decoupled. This way, force shunts can be avoided. This decoupling can be achieved, for example, using seals, flexible hoses, and the like. A maintenance platform of the spinning preparation system, which can be stationary and attached to the spinning preparation machine, can also be decoupled to eliminate additional loads and vibrations on the weighing device when walking on the maintenance platform, as well as force shunts.
[0030] Preferred embodiments are explained below with reference to the drawing figures. With regard to the description of the figures, the same reference numerals may be used in the individual figures to refer to similar or technically corresponding elements. Herein:
[0031] Figure 1 is a longitudinal sectional view of a spinning preparation machine according to a first embodiment of the present invention;
[0032] Figure 2 shows an enlarged view of detail II circled in Figure 1;
[0033] Figure 3 is a plan view of the spinning preparation machine with a weighing system according to an embodiment; and
[0034] Figure 4 is a plan view of the spinning preparation machine with the weighing system according to another embodiment;
[0035] Figure 5 is a flow chart for a method for gravimetric level measurement of the spinning preparation machine; and
[0036] Figure 6 is a longitudinal sectional view of a spinning preparation machine according to a second embodiment of the present invention.
[0037] Figure 1 shows a spinning preparation machine 1 for processing fiber flocks 2 according to a first embodiment, which is designed as a shaft mixer and can be integrated in a blow room line of a spinning mill in a manner known per se.
[0038] To clarify the spatial orientation of the spinning preparation machine 1, Figure 1 shows a longitudinal direction X, a transverse direction Y, and a vertical direction Z, which are defined in terms of a Cartesian coordinate system assigned to the spinning preparation machine 1 and indicated by corresponding arrows. Terms such as "below," "below," "above," or "above" represent spatial information with reference to the vertical direction Z. The spinning preparation machine 1 can be installed on a stationary floor 3 that lies in a horizontal plane spanned by the longitudinal direction X and the transverse direction Y.
[0039] The spinning preparation machine 1 has a tuft storage 4, which is divided into several, here by way of example, six, filling chutes 5 (5.1, 5.2, 5.3, 5.4, 5.5, 5.6) arranged side by side or one behind the other in a feeding direction A. The feeding or transport direction of the fiber air flow is indicated in Figure 1 by arrow A. The filling chutes 5 are spatially separated from one another by perforated partition walls 33.
[0040] Above the filling chutes 5 is a feeding device with a feeding channel 6 and closure members 11 (11.1, 11.2, 11.3, 11.4, 11.5) arranged in the feeding channel 6. The filling chutes 5 are connected to the feeding channel 6 running above the filling chutes 5, which has a bottom opening 7 (7.1, 7.2, 7.3, 7.4, 7.5, 7.6) for each filling chute 5 for filling the filling chutes 5 with the fiber flakes 2. An inlet 8 of the feeding channel 6 is fluidly connected to a central fiber flake inlet 9, which is tubular in design and can in turn be connected on the inlet side to an upstream spinning preparation machine (not shown). The fiber flakes 2 are transported pneumatically by means of a fan 10 through the fiber flake inlet 9 through the inlet 8 into the feeding channel 6.
[0041] In the feeding direction A, between the inlet 8 and the bottom openings 7, a recirculation flap 41 is arranged in the feeding channel 6, which, in its open position, creates a flow-conducting connection between the inlet 8 and a recirculation flap 40. In the open position, the recirculation flap 41 is pivoted into the feeding channel 6 and blocks it downstream of the recirculation flap 41. Figure 1 shows the recirculation flap 41 in its closed position, in which the recirculation flap 41 blocks the recirculation flap 40 and opens the feeding channel 6. The recirculation flap 41 can be moved from the open position to the closed position, and vice versa, by means of an actuator. When material is requested, the recirculation flap 41 is in its closed position to enable the filling chutes 5 to be fed with the fiber flakes 2.If there is no material requirement, the recirculation flap 41 is moved to its open position, in which the transport air, which then accordingly does not transport any fiber flakes, is guided past the filling shafts 5 via the recirculation duct 40.
[0042] The positions of the closure members 11 arranged in the feed channel 6 are adjustable by means of actuators 36. The actuators 36 can be pneumatic actuators, although alternatives such as electromechanical or hydraulic actuators are also possible. Furthermore, the spinning preparation machine 1 has a control unit 37 configured to control the actuators 36 for the targeted filling of the filling chutes 5 with the fiber tufts 2 in such a way that, due to the positions of the closure members 11, only one of the bottom openings 7 is connected to the central fiber tuft inlet 9 at a time. Due to the arrangement of the closure members 11, only five closure members 11 are required for the six filling chutes 5 in this case.Furthermore, the control unit 37 is configured to control the actuator of the recirculation flap 41 in order to move the recirculation flap 41 into its closed position upon material request, so that the fiber flakes 2 can flow through the inlet 8 toward the respectively released bottom opening 7. Each of the closure members 11 can be moved into two positions by means of the associated actuator 36, namely its open position and its closed position, as described in detail below.
[0043] Specifically, at the bottom openings 7.1, 7.2, 7.3, 7.4, 7.5 of the first five filling shafts 5.1, 5.2, 5.3, 5.4, 5.5 in the feeding direction A, one of the closure elements 11.1, 11.2,
[0044] 11.3, 11.4, 11.5. Figure 1 shows that, based on an existing material requirement, the fiber flakes 2 are transported through the fiber flake inlet 9 into the feed channel 6 by means of the transport air A flowing in the feed direction A. The recirculation flap 41, in its closed position, blocks the recirculation channel 40 and opens the feed channel 6. The first closure member 11.1 in the feed direction A is in its open position, so that the fiber flakes 2 flowing into the feed channel 6 through the inlet 8 flow through the first bottom opening 7.1 into the first filling chute 5.1. In its open position, the first closure member 11.1 is pivoted into the feed channel 6 such that the feed channel 6 is blocked downstream of the first bottom opening 7.1 by the first closure member 11.1. Thus, the fiber flakes 2 can only be transported into the first feed chute 5.1.
[0045] When the second filling chute 5.2 is to be filled, the first closure member 11.1 is moved to its closed position, in which the first closure member 11.1 blocks the first bottom opening 7.1 and releases the feed channel 6 downstream of the first bottom opening 7.1. The second closure member 11.2 is then moved to its open position, in which the fiber flakes 2 flowing into the feed channel 6 through the inlet 8 flow through the second bottom opening 7.2 into the second filling chute 5.2, and the feed channel 6 downstream of the second bottom opening 7.2 is now blocked by the second closure member 11.2. The filling of the other filling chutes 5.3, 5.4, and 5.5 takes place in a similar manner.
[0046] Only at the last bottom opening 7.6, none of the closure elements 11 are provided. If the last filling shaft 5.6 is to be filled, the closure elements 11.1, 11.2, 11.3,
[0047] 11.4, 11.5 at the upstream bottom openings 7.1, 7.2, 7.3, 7.4, 7.5 into their closed positions, in which the upstream bottom openings 7.1, 7.2, 7.3, 7.4, 7.5 are closed and the feed channel 6 is open. At a lower end of the flake storage device 4, a discharge device 34 is provided, which has a dosing device 12 for each filling shaft 5 in order to be able to empty the respective filling shaft 5 in a controlled manner. The respective dosing device 12 has a pair of feed rollers 35 with two feed rollers 13, 14 and can further comprise an opening roller 15 arranged below the pair of feed rollers 35. All feed rollers 13, 14 can be driven in rotation via a common drive and preferably rotate at the same input roller speed. In particular, the fiber flakes 2 are removed from the filling chutes 5 simultaneously via the removal device 34.
[0048] Furthermore, an extraction system, operating, for example, with a fresh air supply L, can be connected below the extraction device 34 in order to transport the mixed fiber flakes 2 to the next processing machine, in particular another spinning preparation machine (not shown) in the blowroom line. For this purpose, a mixing channel 16 can be connected below the dosing devices 12, which extends in the longitudinal direction X over the filling shafts 5 in order to transport the removed flake material 2 pneumatically via an outlet 17 through a flow-connected flake outlet 18 to a downstream spinning preparation machine (not shown) in the blowroom line. The flake outlet 18 can be supported on the stationary floor 3 via a pipe holder 32.
[0049] Furthermore, the spinning preparation machine 1 has a machine frame 19, to which the tuft storage 4 with the filling chutes 5, the feeding channel 6 arranged thereon, the take-off device 34, and the mixing channel 16 are attached. Furthermore, a machine housing 20 can be attached to the machine frame 19. The machine frame 19 is supported on the stationary floor 3 via several support points 24, here four as an example. In order to be able to align the machine frame 19 relative to the floor 3, a support foot 25, in particular a height-adjustable one, is provided at each of the support points 24.
[0050] For gravimetric fill level measurement, the spinning preparation machine 1 has a weighing device 26 signal-connected to the control unit 37 in order to be able to calculate the fill weight of fiber flakes 2 via changes in the measured weight force during operation of the spinning preparation machine 1.
[0051] The weighing device 26 has a plurality of load cells 27. The load cells 27 can be arranged at all or at least some of the support points 24 between the machine frame 19 and the stationary floor 3. In order to avoid distortions in the machine frame 19 due to thermal expansion and the associated measurement errors, it is advantageous if the supports allow horizontal displacement, for example through damping elements 28. The load cells 27 can be arranged directly in the machine frame 19, as can be seen in particular in Figure 2. This allows them to be integrated into the existing machine structure. The load cells 27 can be arranged between the machine frame 19 and the support feet 25, which are in particular height-adjustable. Accordingly, the machine frame 19 is supported on the support feet 25 via the load cells 27.According to the example shown, the load cells 27 can be attached to an inner surface of a frame profile of the machine frame 19 facing away from the stationary floor 3. The respective load cell 27 can be attached to the machine frame 19 at an end facing away from the point of application of the support foot 25. The load cells 27 can be shear beam load cells, for example. Alternatives are possible, so that the load cell 27 can be designed, for example, as a compression load cell, a bending beam load cell, a double shear beam load cell, or as simple strain gauges. The load cells 27 can be attached to all support points 24. Accordingly, the spinning preparation machine 1 can have, for example, four of the load cells 27 when configured with six of the filling chutes 5, and six of the load cells 27 when configured with ten of the filling chutes 5.
[0052] Instead of being integrated into the machine frame 19, the load cells 27 can also be arranged directly on the stationary floor 3 and the support feet 25 can stand on the load cells 27.
[0053] Figure 3 shows an embodiment of the spinning preparation machine 1 in which the load cells 27 are provided at all of the four support points 24. In order to create a defined four-point support and thus, for example, to enable a calculation based on force and moment equilibria, it is advantageous to provide resilient elements, such as damping elements 28, at the support points 24.
[0054] Figure 4 shows an alternative embodiment of the spinning preparation machine 1 to Figure 3, in which the load cells 27 are not arranged at all support points 24, but only at a subset of the support points 24.1, 24.2. The support points 24.1, 24.2 provided with the load cells 27 are arranged only on one side of the machine along a main axis 38 of the spinning preparation machine 1 that runs parallel to the longitudinal axis X. In particular, the support points 24.1, 24.2 equipped with the load cells 27 lie on an imaginary connecting line 39 that is aligned parallel to the main axis 38. Thus, no load cells 27 are arranged at the remaining support points 24.3, 24.4, which are located on the other side of the machine.Tests have shown that, over time, the flock material 2 is evenly distributed in the filling shafts 5 along the transverse axis Y, so that a long-term symmetrical weight distribution across the clear frame width can be assumed and is actually present. This allows the static calculation to be simplified to a single-span beam, which is a particularly easy-to-calculate element in statics, and whose support forces can be determined without complex calculation methods. This allows the support forces resulting from the changing filling conditions during operation of the spinning preparation machine 1 at the support points 24.1, 24.2, 24.3, and 24.4 to be determined with minimal computational effort.In the spinning preparation machine 1 designed as a shaft mixer with the six filling shafts 5 shown here as an example, two of the load cells 27 are sufficient to determine the weight, which are arranged on the same machine side and on the imaginary connecting line 39, viewed along the main axis 38. In the spinning preparation machine 1 designed as a shaft mixer with, for example, ten of the filling shafts 5, three of the load cells 27 can be provided due to the greater extension along the machine axis, i.e., the machine length, which are arranged on the same machine side and on the imaginary connecting line 39.
[0055] In order to prevent vibrations from distorting the measurement results using the weighing device 26 and to reduce the introduction of vibration-related interference factors for the gravimetric fill level measurement as much as possible, a vibration-damping element, here a flexible hose element 29, is arranged between the machine housing 20 and the fiber flake inlet 9, which provides a flow-conducting connection between the fiber flake inlet 9 and the inlet 8 into the feed channel 6. Similarly, a vibration-damping element, here a further flexible hose element 31, is arranged between the machine housing 20 and the fiber flake outlet 18, which provides a flow-conducting connection between the mixing channel 16 or the outlet 17 and the fiber flake outlet 18.A platform 30 on which the fan 10 is mounted can be mounted on a vibration-damping element (not shown) at the bottom end to dampen vibrations. This also prevents force shunts, which would result in an incorrect, i.e., insufficient, weight being measured by the weighing device 26.
[0056] Figure 5 shows a simplified flowchart of a method for gravimetric fill level measurement of the spinning preparation machine 1, which can be filled with fiber flakes 2. Possible embodiments are described below, in which not only the information on the setting positions of the closure members 11, or the state of the flaps, but also other optional information from the spinning preparation machine 1 are incorporated into the fill level measurement.
[0057] After starting 50 the method, the control unit 37 determines the operating mode in which the spinning preparation machine 1 is located in step 51. The operating mode can be specified manually by user input. The spinning preparation machine 1 can, for example, be operated in three different operating modes, namely filling mode 60, empty mode 70, and automatic mode 80. In the filling mode 60, a filling process takes place in which at least one of the filling chutes 2 is filled with the fiber flakes 2 and the take-off device 34 is stationary. The filling mode 60 can, for example, serve to fill the spinning preparation machine 1 with the fiber flakes 2 to produce an initial supply.
[0058] Specifically, in step 61 of the filling operation 60, the control unit 37 queries whether there is a material request. This information can be provided by a higher-level controller, for example, a Line Commander. Furthermore, a material sensor could also be arranged in the fiber flake inlet 9. As an additional value, the status of the feed rollers 13, 14 can be queried, which should then be switched off. The filling weight of fiber flakes 2 in the flake storage 4 can be calculated from the weight force (total weight) measured by the weighing device 26 at the beginning of a defined time interval (starting point; t = 0 seconds) minus a predetermined empty or tare weight.From the weight force measured at the end of the defined time interval (end point; example: t = 5 seconds), the control unit 37 calculates the mass difference resulting from the filling of the filling chutes 5 in the defined time interval after subtracting the weight force measured at the starting point. The defined time interval can be, for example, one to five seconds, although longer or shorter time intervals are also possible. The measurement of the change in weight force in the defined time interval is preferably repeated continuously during operation of the spinning preparation machine 1, i.e., it always starts from the beginning in order to be able to repeatedly calculate the change in the filling weight and, based on this, the fill levels of the filling chutes 5.
[0059] Due to the above-described control of the closure members 11, only one of the filling chutes 5 can be filled at a time. Thus, in step 62, the control unit 37 can compare which filling chute 5 was open for how long during the defined time interval and which of the filling chutes 5 was thus filled with the fiber flakes 2. Since only one of the filling chutes 5 can be filled at any given time, the corresponding portion of the measured weight difference can be allocated to the respective filling chute 5.
[0060] In the idle operation mode 70, an emptying process takes place in which no feeding with fiber flakes 2 takes place and the take-off device 34 draws the fiber flakes 2 from the filling chutes 5. The idle operation 70 can be used, for example, to remove residual amounts of fiber flakes 2 from the spinning preparation machine 1 and in particular from the filling chutes 5 during a material change. In other words, in the idle operation 70, no material is requested, i.e., no fiber flakes 2 reach the feeding channel 6 via the fiber flake inlet 9, and the filling chutes 5 are merely emptied. Specifically, in step 71 of the idle operation 70, the control unit 37 queries the status of the feed rollers 13, 14, in particular whether the feed rollers 13, 14 are rotating and at what feed roller speed they are driven in rotation. In step 72, the control unit 37 calculates the fill levels of the filling shafts 5.For this purpose, the control unit 37 calculates the change in the filling weight in the defined time interval, as already described using the example of the filling operation 60. The mass difference is calculated from the change in weight force detected by the weighing device 26, which is consequently a negative weight difference in the empty operation 70. Because the withdrawal device 34 withdraws the fiber flakes 2 from all filling chutes 5 simultaneously, the mass difference can be evenly distributed across all filling chutes 5. In other words, the fill level in all filling chutes 5 empties by the same amount. Due to the identical design of the feed rollers 13, 14, which are coupled to a common drive, they rotate at the same speeds. If, on the other hand, the feed rollers 13, 14 in the respective filling chute 5 are equipped with their own individual drive, it can be determined for each filling chute 5 whether it is emptying.During empty operation, the filling shafts 5 are thus emptied, whereby a partial or complete emptying of the filling shafts 5 is possible.
[0061] Whenever the filling chutes 5 are not being fed and the fiber flakes 2 are being removed from the filling chutes 5 via the take-off device 34, i.e., during the pure emptying process, the control unit 37 can calculate the production of the spinning preparation machine 1 in such a time interval depending on the feed roller speed. Based on this, the control unit 37 can derive the production for other speeds. For this purpose, speed-dependent production curves can be stored in the control unit 37, for example.
[0062] In the automatic operation mode 80, which is usually present during the operation of the spinning preparation machine 1, the following cases can be distinguished or occur:
[0063] Filling process (see filling operation 60);
[0064] Emptying process (see Emptying operation 70); or
[0065] Simultaneous filling and emptying process (see filling and emptying operation 60, 70).
[0066] In step 81 of automatic operation 80, the control unit 37 queries the status of the feed rollers 13, 14. When the feed rollers 13, 14 are driven in rotation, the filling chutes 5 are emptied. In step 82, it is also queried whether a material request exists. If the material request exists, filling takes place. The actual material flow through the fiber tuft inlet 9 into the feeding channel 6 can optionally be confirmed with additional sensors in the pipeline, for example in the fiber tuft inlet 9. It is possible that a material request exists in filling mode, but no tuft material 2 is currently being delivered from the upstream spinning preparation machine. During this time, weight changes measured by the weighing device 26 could indicate malfunctions.
[0067] During pure emptying in automatic mode (emptying process), the production of the spinning preparation machine 1 is regularly determined by the control unit 37 depending on the feed roller speed. This is advantageously always carried out when the filling chutes 5 are as full as possible, i.e., at least 50 percent full. This can be determined, for example, via differential pressure measurements and / or light barriers. Based on the change in total weight, the production for the respective fiber material 2 can be determined depending on the feed roller speed.
[0068] During simultaneous filling and emptying, in addition to information on the setting positions of the closure elements 11, the mass difference measured by the weighing device 26, and the status of the feed rollers 13, 14, the weight distribution between the load cells 27 measured by the weighing device 26 can also be used. This results from the varying filling of the filling chutes 5 over the length of the machine. The signal from each individual load cell 27 is used separately. During simultaneous filling and emptying in automatic mode, the previously determined production can be used depending on the feed roller speed. Together with the change in the total weight, the mass of the fed fiber flakes 2 can be determined.
[0069] The mass difference measured by the weighing device 26 during automatic operation in the recurring time interval, which may be 5 seconds, for example, which results from the change in the fill weight, is taken into account in step 83 when the control unit 37 calculates the fill levels of the filling chutes 5 depending on the setting positions of the closure members 11 in the respective time interval. Furthermore, the production of the spinning preparation machine 1 is taken into account, since the fiber flakes 2 are drawn off via the draw-off device 34. Due to the control of the closure members 11 described above, only one of the filling chutes 5 can be filled at a time. Thus, the control unit 37 can compare in step 83 which of the filling chutes 5 was open for how long in the defined time interval and into which of the filling chutes 5 the fiber flakes 2 thus ended up.Since only one of the filling shafts 5 can be loaded at any given time, the corresponding portion of the weight difference measured in the time interval can be allocated to the respective filling shaft 5.
[0070] In step 90, the calculated fill levels of the filling chutes 5 are output, for example on a display on the spinning preparation machine 1 and / or via a data interface for remote displays, for example a portable or stationary terminal.
[0071] Example sequence of automatic operation 80:
[0072] Steps 81 and 82 result in no fiber flakes 2 being fed through the fiber flake inlet 9 and in the feed rollers 13, 14 rotating. The filling chutes 5 are thus emptied (emptying process). In the defined time interval, the weight force with which the weighing device 26, in particular the load cells 27, are loaded is measured at the starting point t = 0 and at the end point, here as an example, after 5 seconds. If all of the support points 24 are equipped with load cells 27, as shown in Figure 3, then the sum of all measured weight forces results in the weight value (total weight). If the load cells 27 are arranged only on one side of the machine, i.e., only half of the support points 24 are equipped with load cells 27, as shown in Figure 4, then the sum of all measured weight forces multiplied by a factor of 2 results in the weight value (total weight).The filling weight is calculated by subtracting the empty weight from the weight value.
[0073] Filling weight 1 at time t = 0 delivers m = 100 kilograms [kg]
[0074] Filling weight 2 at time t = 5 seconds [s] delivers m = 99 kg
[0075] Calculated production: 720 kilograms per hour [kg / h] at the current input roll speed, which may, for example, correspond to 70 percent of the maximum input roll speed.
[0076] In the subsequent automatic operation 80, material is now fed, i.e., the fiber flakes 2 are fed into the feeding channel 6 via the fiber flake inlet 9. In step 83, depending on the setting position of the closure members 6, the measured mass difference, i.e., the change in fill weight, can now be specifically distributed among the individual filling chutes 5. Furthermore, the filling chutes 5 are emptied, i.e., the feed rollers 13, 14 are driven in rotation. Thus, the filling chutes 5 are simultaneously filled and emptied (filling and emptying process). In the recurring, newly defined time interval, the weight with which the weighing device 26, in particular the load cells 27, are loaded is measured at the starting point t = 0 and at the end point, here as an example, after 5 seconds, and from this, the fill weight at the starting and end points is calculated, as already described above.
[0077] Filling weight 1 at time t = 0 delivers m = 100 kg
[0078] Filling weight 2 at time t = 5 s delivers m = 101 kg Input roller speed unchanged at roller speed 70 percent results in production of 720 kg / h (value for the production from the emptying process)
[0079] Calculation of the change in filling weight: 101 kg - 100 kg + 72 s = 2 kg
[0080] In step 83, the mass difference (change in fill weight) is distributed among the filling chutes 5.1, 5.2, 5.3, 5.4, and 5.5 to calculate the fill levels. For this purpose, the supplied mass of, in this case, 2 kilograms is assigned to the filling chute 5 that was connected to the central fiber flake inlet 9 during the defined time interval due to the setting positions of the closure elements 11.
[0081] Calculated individual shaft fillings can still be regularly compared using pressure signals and / or light barriers as a reference point and corrected if necessary.
[0082] Figure 6 shows a spinning preparation machine 1 according to a second embodiment, which largely corresponds to the previously described embodiment, so that reference is made to the above description regarding the similarities. The difference lies in the design of the substructure on which the machine frame 19 is supported.
[0083] A decoupling device 21 is arranged below the machine frame 19, which functions as a base frame for a machine structure 22 comprising the machine frame 19, the flake storage 4 with the filling chutes 5 and the feed channel 6, as well as the machine housing 20. The machine frame 19 and, in a further embodiment, the entire machine structure 22 is / are supported or mounted on the decoupling device 21 at a distance from the stationary floor 3.The decoupling device 21 can, for example, be designed as a self-contained intermediate frame 23, which, here as an example, has four support points 24 for installation on the stationary floor 3. It goes without saying that with a larger or heavier spinning preparation machine, additional support points 24 can be added, or with a smaller spinning preparation machine, three support points 24 generally ensure secure support. A support foot 25, in particular a height-adjustable one, is provided at each of the support points 24 in order to be able to align the decoupling device 21 relative to the floor 3.
[0084] The weighing device 26 for gravimetric level measurement of the flock storage 4 is arranged between the intermediate frame 23 and the machine frame 19. This weighing device is located in the force flow between the filling chutes 5 and the stationary floor 3. Specifically, as shown here, the weighing device 26 can have several load cells 27 on which the weight of the machine structure 22 rests. Damping elements 28 can be arranged between the load cells 27 and the decoupling device 21, here, for example, the intermediate frame 23. To prevent the measurement results obtained by the weighing device 26 from being distorted by vibrations of the fan 10, the platform 30 for the fan 10 can be supported on the decoupling device 21. The pipe holder 32 for the fiber flock outlet 18 can be supported on the intermediate frame 23.
[0085] Reference symbol
[0086] 1 spinning preparation machine 70 idle operation
[0087] 2 fiber flakes 71 step
[0088] 3 Floor 72 Step
[0089] 4 flake storage 80 automatic operation
[0090] 5 filling shaft 90 output
[0091] 6 Feed channel
[0092] 7 Floor opening
[0093] 8 Entrance
[0094] 9 Fiber flake inlet A Feeding or transport direction
[0095] 10 Fan L Fresh air supply
[0096] 11 Closure element X Longitudinal direction
[0097] 12 Dosing device Y transverse direction
[0098] 13 Feed roller Z vertical direction
[0099] 14 Feed roller
[0100] 15 Opening roller
[0101] 16 mixing channel
[0102] 17 Outlet
[0103] 18 Flake outlet
[0104] 19 Machine frame
[0105] 20 Machine housing 21 Decoupling device
[0106] 22 Machine structure
[0107] 23 intermediate frames
[0108] 24 support point
[0109] 25 Support foot
[0110] 26 Weighing device
[0111] 27 load cells
[0112] 28 Damping element
[0113] 29 Hose element
[0114] 30 Platform 31 Hose element
[0115] 32 Pipe holder
[0116] 33 Partition wall
[0117] 34 trigger device
[0118] 35 feed roller pair
[0119] 36 Actuator
[0120] 37 Control unit
[0121] 38 Main axis
[0122] 39 connecting line
[0123] 50 Start 51 Step 60 Filling operation
[0124] 61 steps
[0125] 62 steps
Claims
Patent claims 1. Method for gravimetric level measurement of a spinning preparation machine (1) for processing fiber flakes (2) that is to be erected or is erected on a stationary floor (3), wherein the spinning preparation machine (1) has several adjacent filling chutes (5) for the fiber flakes (2), a feed channel (6) arranged above the filling chutes (5) which is connected on the inlet side to a central fiber flake inlet (9) and has a bottom opening (7) on the outlet side for each filling chute (5), several closing elements (11) arranged in the feed channel (6) which are adjustable by means of actuators (36), and a control unit (37) which is configured to control the actuators (36) for filling the filling chutes (5) with the fiber flakes (2) such that, due to the position of the closing elements (11), only one of the bottom openings (5) is connected to the central fiber flake inlet (9) at any given time. is,a discharge device (34) arranged below the filling chutes (5), which is connected on the inlet side to the filling chutes (5) and on the outlet side to a central fiber flake discharge (18), and a weighing device (26) connected to the control unit (37) by signal, which is arranged in the force flow between the filling chutes (5) and the stationary floor (3), and wherein the method comprises the following process steps: 1) Measuring a change in weight force using the weighing device (26) in a defined time interval during a filling and / or emptying process; 2) Calculating a change in the filling weight of the filling shafts (5) by the control unit (37) from the change in the weight force in the defined time interval; 3) Calculating the fill levels of the filling shafts (5) by the control unit (37), whereby the change in the fill weight is distributed to the at least one filling shaft (5) which was connected to the fiber flake inlet (9) during the defined time interval due to the positioning positions of the closing devices (11).
2. Method according to claim 1, characterized in that the method steps 1) - 3) are repeated during the filling and / or emptying process.
3. Method according to claim 1 or 2, characterized in that the dispensing device (34) has a feed roller pair (35) for each filling chute (5), wherein The control unit (37) for calculating the fill levels takes into account the feed roller rotational speed of the feed roller pairs (35). A method according to claim 3, characterized in that the control unit (37) derives a production output of the spinning preparation machine (1) as a function of the feed roller rotational speed from the change in the weight force, which is measured by means of the weighing device (26) in a time window in which no feeding of the filling chutes (5) takes place. A spinning preparation machine (1) for processing fiber flakes (2), wherein the spinning preparation machine (1) is to be set up on a stationary base (3) and has several filling chutes (5) arranged side by side, a feeding channel (6) arranged above the filling chutes (5) which is connected on the inlet side to a central fiber flake inlet (9) and has a bottom opening (7) on the outlet side for each filling chute (5).The machine comprises several closing elements (11) arranged in the feed channel (6), which are adjustable by means of actuators (36), a control unit (37) configured to actuate the actuators (36) for filling the filling chutes (5) with the fiber flakes (2) such that, due to the positioning positions of the closing elements (11), only one of the bottom openings (7) is connected to the central fiber flake inlet (9) at any given time, and a discharge device (34) arranged below the filling chutes (5), which is connected on the inlet side to the filling chutes (5) and on the outlet side to a central fiber flake discharge (18), characterized in that the spinning preparation machine (1) is configured to carry out a method according to one of claims 1 to 4 and has a weighing device (26) connected to the control unit (37) by means of a signal.which is arranged in the force flow between the filling chutes (5) and the stationary floor (3). Spinning preparation machine (1) according to claim 5, characterized in that the spinning preparation machine (1) has at least three support points (24) for placement on a stationary floor (3), wherein the weighing device (26) has a load cell (27) for each support point (24), which is attached to the respective support point (24). Spinning preparation machine (1) according to claim 5, characterized in that the spinning preparation machine (1) has at least four support points (24) for placement on a stationary floor (3), wherein the weighing device (26) has several load cells (27) which are attached to only a subset of the support points (24), wherein the load cells (27) are equipped with the load cells, Support points (24) lie on an imaginary connecting line (39) that is aligned parallel to a main axis (38) of the spinning preparation machine (1). Spinning preparation machine (1) according to one of claims 5 to 7, characterized in that the spinning preparation machine (1) has a machine frame (19) to which the filling chutes (5) are attached. Spinning preparation machine (1) according to claim 8, characterized in that the load cells (27) are arranged between the machine frame (19) and the stationary floor (3).Spinning preparation machine (1) according to claim 8, characterized in that the spinning preparation machine (1) has a decoupling device (21) with at least four support points (24) for setting up on a stationary floor (3), wherein the machine frame (19) and the decoupling device (21) are structurally separated from each other, and the load cells (27) are arranged between the decoupling device (21) and the machine frame (19).