Spinning Preparation Fill-Level Control Using Gravimetric Chute Tracking
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Solution Overview
Problem
Existing spinning preparation machines with multiple hoppers face issues of uneven fiber distribution, leading to individual hoppers running empty and disrupting production, as mere fill weight measurements are insufficient for maintaining uniform production.
Innovation Solution
A method and machine design incorporating adjustable closing devices controlled by a unit to ensure only one chute is filled at a time, combined with continuous weight measurement and calculation of fill levels across chutes, allowing precise distribution and prevention of empty chutes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple filling chutes are filled simultaneously from a central fiber flock inlet, then the filling process is efficient and quick, but the fiber flocks are distributed very unevenly across the hoppers causing some to run empty
Solution Approach 1:
The control unit determines the positions of closing devices before initiating the filling process, and pre-calculates which filling chute(s) should receive fiber material based on current fill levels. This preliminary determination ensures that when filling begins, the material is directed to the correct chute(s) to maintain uniform distribution and prevent any chute from running empty.
Solution Approach 2:
The system dynamically adjusts the operation of closing devices during the filling process based on real-time weight measurements from load cells. The control unit continuously monitors fill levels and actuates closing devices to redirect fiber material to different chutes as needed, transforming a static simultaneous-filling approach into a dynamic, adaptive distribution system that maintains uniformity while preserving efficiency.
2Measurement precision
If the fill weight of fiber flocks is measured using load cells, then the total fill weight can be determined, but it is insufficient to detect individual chute emptying
Solution Approach 1:
The measurement system is segmented into multiple load cells, each positioned to measure the weight of fiber material in specific filling chutes independently. This segmentation transforms a single aggregate weight measurement into multiple individual measurements, allowing the control unit to track the fill level of each chute separately and identify when any individual chute is approaching empty status.
Solution Approach 2:
The closing devices act as intermediaries between the central fiber flock inlet and individual filling chutes. By controlling the position of these closing devices, the system can direct fiber material to specific chutes and simultaneously use the weight measurements to infer the fill status of each chute, thereby recovering the lost individual chute information through the intermediary mechanism.
3Reliability
If closing devices are added to control fiber distribution to individual chutes, then uniform fill levels can be maintained, but the device complexity increases
Solution Approach 1:
The closing devices are designed to perform multiple functions: they serve as flow control elements to direct fiber material to specific chutes, act as measurement reference points for determining which chute should be filled next, and function as actuatable valves that can be rapidly opened or closed based on control unit decisions. This multi-functionality reduces the need for separate components and justifies their inclusion despite the added complexity.
Solution Approach 2:
The control unit changes the operational parameters of closing devices (open/closed positions, timing of actuation) based on real-time weight measurements and calculated fill levels. By dynamically adjusting these parameters, the system maintains uniform fiber distribution across all chutes. The complexity is managed through automated control algorithms that optimize the operation of these devices based on measured parameters.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures uniform production by preventing individual chutes from running dry, maintaining consistent fill levels, and optimizing production based on real-time weight changes, independent of material properties or distribution.
Implementation Method 1
Measuring a change in weight force using the weighing device within a defined time interval
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a method for gravimetrically measuring the fill level of a spinning preparation machine (1), which can be erected or is erected on a stationary floor (3), for processing fibre flocks (2), the spinning preparation machine (1) having: a plurality of feed shafts (5) for the fibre flocks (2), said feed shafts being arranged adjacent to one another; a loading channel (6) which is located above the feed shafts (5), the inlet side of said loading channel being connected to a central fibre flock infeed (9) and the outlet side of said loading channel having a bottom opening (7) for each feed shaft (5); a plurality of closing elements (11) which are located in the loading channel (6) and which can be adjusted by means of actuators (36); a control unit (37) which is designed to control the actuators (36) in order to fill the feed shafts (5) with the fibre flocks (2) in such a way that, due to adjustment positions of the closing elements (11), only one of the bottom openings (5) is connected to the central fibre flock infeed (9) at any one time; a discharge device (34) which is located below the feed shafts (5) and the inlet side of which is connected to the feed shafts (5) and the outlet side of which is connected to a central fibre flock outfeed (18); and a weighing device (26) which is connected to the control unit (37) by means of signals and is located in the force flow between the feed shafts (5) and the stationary floor (3). The method comprises the following method steps: measuring a change in a weight on the weighing device (26) in a defined time interval during a filling and/or emptying process; calculating a change in a fill weight of the feed shafts (5) using the control unit (37) based on the change in the weight in the defined time interval; calculating the fill levels of the feed shafts (5) using the control unit, wherein the change in the fill weight is distributed to the at least one feed shaft (5) which was connected to the fibre flock infeed (9) in the defined time interval on the basis of the adjustment positions of the closing elements. The present invention also relates to a spinning preparation machine.