Liquid Flowmeter Calibration Using Recirculating Tank and Feedback Control
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Solution Overview
Problem
Current liquid flowmeter calibration methods are time-consuming, wasteful, and prone to errors due to the need to stop production lines and fail to accurately replicate the actual operating environment, leading to inefficiencies and raw material losses.
Innovation Solution
A semi-automatic or automatic calibration method that reuses the calibration liquid, controls the environment to match actual operating conditions, and adjusts the flow rate to match actual operating parameters, using 2-way or 3-way valves and a feedback control system to ensure accuracy and reduce production downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the entire manufacturing process is stopped for flowmeter calibration, then the flowmeter can be calibrated with known weights, but the production time is lost and the calibration liquid cannot be immediately utilized
Solution Approach 1:
The patent implements preliminary action by preparing the calibration system in advance with a separate calibration tank and pump arrangement. The calibration liquid is pre-positioned in a dedicated calibration tank, and the calibration pump is ready to operate independently. This allows the calibration process to be initiated quickly without disrupting the main production flow, as all calibration components are pre-configured and ready to use.
Solution Approach 2:
The patent segments the calibration function from the main production system by using a separate calibration tank, calibration pump, and dedicated calibration circuit. This segmentation allows calibration operations to be performed independently without stopping the production line, as the calibration system operates in parallel with the production system. The production pump continues delivering liquid to the mixing tank while the calibration pump operates the calibration liquid through the flowmeter.
2Ease of manufacture
If the calibration liquid is weighed at the flowmeter-installing point, then the calibration can be performed, but the weight measurement deviates from the actual point-of-use due to pressure and flow rate differences
Solution Approach 1:
The patent introduces an intermediary weighing system that measures the calibration liquid weight at the calibration tank location rather than at the flowmeter installation point. A weighing device (load cell or scale) is installed on the calibration tank support structure to measure the weight of calibration liquid discharged. This intermediary measurement approach, combined with flow rate control, eliminates the need to transport the liquid to the actual point-of-use for weighing, while still achieving accurate calibration results.
Solution Approach 2:
The patent applies parameter changes by controlling the flow rate of calibration liquid to match the actual operating flow rate at the point-of-use. The system measures or calculates the actual flow rate and adjusts the calibration pump operation to replicate these conditions. By matching the flow rate parameter and controlling pressure conditions, the calibration becomes accurate even though the weight is measured at a different location from the flowmeter installation point.
3Productivity
If the calibration environment differs from the actual operating environment, then the calibration can be performed quickly, but errors are introduced due to machine wear, pressure loss, and height differences
Solution Approach 1:
The patent implements parameter changes by actively controlling and matching the calibration environment parameters to the actual operating parameters. The system measures or calculates the actual flow rate and pressure conditions at the point-of-use and adjusts the calibration pump operation to replicate these conditions. By matching flow rate, pressure, and other relevant parameters, the calibration becomes accurate despite being performed in a different physical location and time, eliminating errors from machine wear and environmental differences.
Solution Approach 2:
The patent employs feedback mechanisms to ensure calibration accuracy by continuously monitoring and adjusting calibration parameters. The system measures the actual operating flow rate and uses this information to control the calibration pump operation. Flow sensors, pressure sensors, or calculated flow rates provide feedback to the control system, which adjusts the calibration process to match actual operating conditions. This feedback loop ensures that calibration is performed under representative conditions, eliminating errors from environmental differences.
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
The method allows for quick, accurate, and cost-effective calibration of liquid flowmeters, reducing production line stoppage time and raw material waste, while minimizing errors caused by environmental differences and equipment wear.
Implementation Method 1
a pump for delivering the liquid from said liquid storage tank through said liquid delivering line back to said first tank
Implementation Method 2
a liquid flowmeter for measuring a flow rate of the liquid flowing therein
Implementation Method 3
at least one weighing sensor for measuring a weight of the liquid in said first tank
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A calibration method for a liquid flowmeter(20) comprising: providing a first tank (12) for receiving the liquid to be measured and a liquid storage tank (14) connected to the first tank (12); providing a liquid delivering line (9) for conveying the liquid from the liquid storage tank (14) to an external device; providing a weighing sensor (22) for weighing the liquid contained in either the first tank (12) or the liquid storage tank (14), wherein during performing the calibration for the flowmeter (20): disconnecting the liquid delivering line (9) in a conveyance direction downstream of the liquid flowmeter) 20) from the external device; connecting the liquid delivering line (9) in the conveyance direction downstream of the liquid flowmeter (20) to a calibrating line (7) connected to the first tank (12); and determining a flow rate of the conveyed liquid within a predetermined time interval based on the change in the liquid weight measured by the weighing sensor (22) in the predetermined time interval, wherein the liquid from the liquid storage tank (14) is delivered through the liquid delivering line (9) back to the first tank (12), and the flow rate of the liquid from the liquid storage tank (14) to the first tank (12) is controlled so as to be substantially constant during calibration.