Calibrating Conveying Devices for Liquid Dosing Accuracy
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Solution Overview
Problem
Existing methods for calibrating conveying devices used in metering systems suffer from underdosing due to the detection of air in the conveying path, leading to an underestimation of the conveying capacity and subsequent overdosing issues when the calibration interval is interrupted by air detection.
Innovation Solution
The detection area of the detector is arranged in a docking unit or suction lance close to the inlet, allowing for precise calibration by minimizing the empty volume between the inlet and detection area, and using specific counting spans to account for empty volumes, ensuring accurate dosing parameters are adjusted based on a reference volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the detection area is arranged downstream of the pump in the conveying path, then the detector can detect air presence to determine delivery rate, but the empty volume between inlet and detection area causes underdosing during calibration and subsequent dosing errors
Solution Approach 1:
The patent moves the detection area from a downstream position in the conveying path to an upstream position within the docking unit or suction lance, effectively changing the spatial dimension of detection. This repositioning allows the detector to identify air presence before the empty volume significantly impacts the dosing process, thereby resolving the contradiction between measurement capability and dosing precision.
Solution Approach 2:
By placing the detection area upstream in the docking unit or suction lance, the system performs preliminary detection of air presence before the conveying process fully engages with the empty volume. This early detection enables the control unit to adjust calibration parameters in advance, preventing underdosing errors before they occur during actual dosing operations.
2Reliability
If air is sucked in to detect empty level, then the detector can identify when the container is empty, but the empty volume must be pumped out additionally causing underdosing
Solution Approach 1:
The system uses the detector's air presence signal as feedback to the control unit, which then adjusts the calibration parameters accordingly. When air is detected in the upstream detection area, the control unit compensates for the upcoming empty volume by modifying the dosing parameters, ensuring that the correct liquid quantity is delivered despite the presence of air in the conveying path.
Solution Approach 2:
The patent changes the calibration parameters based on the detection state. When air is detected in the upstream detection area, the system adjusts parameters such as the calibration counting range or pump cycle duration to account for the empty volume that will be pumped, thereby maintaining accurate liquid delivery quantity despite the air presence.
3Measurement precision
If the calibration counting range includes the time to pump air out, then the detector can accurately measure the full conveying cycle, but the delivery capacity is underestimated leading to overdosing
Solution Approach 1:
The upstream detection area enables preliminary identification of air presence before the calibration process begins. This allows the control unit to pre-adjust the calibration parameters by subtracting the expected empty volume time from the calibration counting range, ensuring that only the liquid delivery portion is measured for calibration, thus preventing delivery capacity underestimation and subsequent overdosing.
Solution Approach 2:
The system applies preliminary anti-action by detecting air in the upstream detection area and preemptively adjusting the calibration parameters to compensate for the empty volume. This counteracts the potential harmful effect of including air pumping time in the calibration measurement, ensuring accurate delivery capacity determination and preventing overdosing errors.
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
This approach enables precise calibration and dosing by reducing the empty volume in the conveying path, saving time and energy, and ensuring accurate delivery of liquid, thereby preventing underdosing and overdosing issues.
Implementation Method 1
detecting a change from liquid to air in the detection area by the at least one detector
Data Source
Figure 1a~2b
Figure 3a~5
Figure 6a~6b
AI summary
Method for calibrating at least one conveying device (1) for conveying liquid (9) and/or air (7) of a metering device (32) for metering a liquid (9) from at least one inlet (28) to at least one outlet (29), in particular from at least one container (3) to at least one induction distributor (46) and/or at least one target device (45), by means of the at least one conveying device (1), wherein a detection area (14) of at least one detector (15) for distinguishing between liquid (9) and air (7) is arranged between the at least one inlet (28) and the at least one outlet (29), comprising the following method steps: - Connecting at least one, in particular interchangeable, container (3) to the at least one inlet (28) by means of at least one docking unit (2) for coupling to the at least one container (3) and/or by means of a suction lance for introducing into the at least one container (2),wherein the detection area (14) of the at least one detector (15) is arranged in the docking unit (2) and/or in or on the suction lance, - starting the conveying of liquid (9) and/or air (7) by the at least one conveying device (1) responding to a start counting point (33), - detection of a change from liquid (9) to air (7) in the detection area (14) by the at least one detector (15) to an air detection counting point (39), - using the interval between the start counting point (33) and the air detection counting point (39) as a calibration counting span (42) for calibrating the at least one conveying device (1), and/or with the following process steps: - connecting at least one, in particular interchangeable, container (3) to the at least one inlet (28), - starting the conveying of liquid (9) and/or air (7) by the at least one conveying device (1) responding to a start counting point (33)- Detection of a change from air (7) to liquid (9) in the detection range (14) by the at least one detector (15) to a liquid detection counting point (34), - Detection of a change from liquid (9) to air (7) in the detection range (14) by the at least one detector (15) to an air detection counting point (39), - Use of the interval between the liquid detection counting point (34) and the air detection counting point (39) as a calibration counting span (42).,