Multi-Gas Rotameter Flowmeter With Dual Floats and Calibrated Scales
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Solution Overview
Problem
Existing flowmeters for welding gases are limited by requiring separate scales or correction factors for different gases, leading to inefficiencies and increased time and cost when switching between shielding gases, and pressure compensated designs result in gas surges and wastage.
Innovation Solution
A flowmeter with a single unit featuring multiple calibrated scales for various gases, including pressure compensated and non-compensated versions, and adjustable scales for different set pressures, using distinct floats of varying densities to accurately measure gas flow rates for carbon dioxide, argon, nitrogen, and helium, with a transparent rotameter tube and outer cover for precise calibration and reduced gas consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single flowmeter is used for multiple gases with different densities, then device complexity and cost are reduced, but measurement precision deteriorates without correction factors
Solution Approach 1:
The flowmeter is designed with multiple calibrated scales on a single device, each scale corresponding to a different gas type (helium, nitrogen, argon, carbon dioxide). This allows one flowmeter to perform multiple measurement functions without requiring separate devices for each gas, thereby reducing overall system complexity while maintaining measurement precision through proper scale selection.
Solution Approach 2:
The flowmeter incorporates correction factors that adjust the reading based on the specific gas being measured. By changing the parameter of gas type and applying the corresponding correction factor, the device maintains measurement precision across different gases with varying densities, eliminating the need for multiple specialized flowmeters.
2Ease of operation
If pressure compensated flowmeters are used, then flow rate control is improved, but gas wastage increases due to pressure surges
Solution Approach 1:
The flowmeter includes a needle valve positioned upstream of the orifice that allows pre-adjustment of the gas flow before it reaches the pressure-compensating mechanism. By preliminarily controlling the flow rate through the needle valve, the system reduces the magnitude of pressure surges that occur when the solenoid activates, thereby decreasing gas wastage while still maintaining accurate flow control.
3Loss of substance
If non-compensated flowmeters are used, then gas wastage is reduced, but flow rate control and reliability deteriorate
Solution Approach 1:
The flow control system is segmented into two independent components: a needle valve for primary flow adjustment and a solenoid-operated orifice for precise flow control. This segmentation allows the system to operate without pressure compensation mechanisms, reducing gas wastage, while still achieving reliable flow rate control through the coordinated action of both components.
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 flowmeter reduces gas wastage by up to 60% and provides accurate, efficient measurement across a range of gases and pressures, improving usability and reducing operational costs by allowing seamless switching between shielding gases without the need for multiple devices.
Implementation Method 1
first and second floats having different material properties received within the transparent rotameter tube
Implementation Method 2
a transparent rotameter tube provided in a centre of the pressurized chamber
Data Source
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AI summary
A gas flowmeter and associated method of forming a glass flowmeter includes a body having a passage that communicates with an inlet and an outlet for receiving gas flow therethrough. A selectively variable valve controls a flow of gas to the outlet, and plural calibrated scales are operatively associated with the passage to represent a flow rate of gas through the passage. First and second floats having different material properties are received in the passage and are viewable in operative association with the calibrated scales.