Liquid Sampling Apparatus with Constant Flow Control
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Solution Overview
Problem
Current liquid sampling systems fail to provide representative samples across the entire depth of a liquid body due to varying liquid properties and non-constant flow rates, leading to contamination and incomplete stratified layer analysis.
Innovation Solution
A sampling apparatus with an inner sampling tube and valve assembly that maintains a constant inlet pressure head, allowing for a constant flow rate of liquid into the sampling chamber, independent of external pressure, and includes a collar and non-return valves to control liquid entry and exit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a sampling chamber is lowered through liquid with multiple sampling apertures, then liquid can be continuously sampled along the depth, but the sampling flow rate increases with depth due to increasing liquid pressure, resulting in non-representative samples
Solution Approach 1:
An inner sampling tube is introduced as an intermediary component between the sampling chamber and the liquid. The tube extends from the base cap upward into the sampling chamber, with its outlet positioned at a specific height. This intermediary structure channels liquid flow in a controlled manner, ensuring that liquid enters the sampling chamber at a constant rate independent of external pressure variations with depth.
Solution Approach 2:
The invention changes the flow regime parameter by using the inner sampling tube to maintain a constant pressure head for liquid entry. The tube's outlet is positioned at a specific height above the base cap, creating a fixed pressure differential that remains constant throughout the sampling process, regardless of the sampling chamber's depth in the liquid.
2Ease of operation
If the sampling chamber is raised back through the liquid after sampling, then the sample can be retrieved, but liquid contamination occurs as liquid continues to enter the chamber and mix with the sample
Solution Approach 1:
Non-return valves are installed at the sampling apertures and/or inner sampling tube outlet before the sampling process begins. These valves are configured to automatically close when the sampling chamber is raised or when liquid pressure decreases, preventing liquid from entering the sampling chamber during retrieval. This preliminary protective measure ensures sample integrity without requiring manual intervention during the retrieval process.
3Productivity
If multiple sampling apertures are used at the top of the sampling chamber, then air can escape during descent, but liquid pressure increase with depth causes increased flow rate into the chamber
Solution Approach 1:
The sampling system is segmented into distinct functional zones: the inner sampling tube handles liquid intake with controlled flow, the sampling chamber provides the collection volume, and non-return valves at different locations (inlet aperture and/or tube outlet) provide independent flow control. This segmentation allows air venting to occur through the sampling apertures while liquid flow is independently controlled through the inner sampling tube, resolving the conflict between air escape and flow rate consistency.
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 a representative liquid sample across the entire depth range with a constant flow rate, preventing contamination and allowing for accurate analysis without the need for decanting, thereby improving the accuracy and integrity of the sampling process.
Implementation Method 1
The inner sampling tube in use thereby defines a fixed constant inlet pressure head for fluid flowing into the sampling apparatus
Implementation Method 2
The inlet valve assembly comprises an inlet aperture and a non-return valve
Implementation Method 3
The collar is slidably attached to the body section, and is slidable between a first position and a second position
Implementation Method 4
The inlet is therefore in use at a greater liquid pressure than the outlet, thereby forcing liquid to flow into the sampling chamber through the inlet
Data Source
AI summary
A sampling apparatus for taking a liquid sample includes an inlet, a sample housing defining a sampling chamber for the liquid sample, and a sampling tube through which, in use, a flow of liquid to be sampled flows from the inlet into the sampling chamber. The sampling tube extends a predetermined distance within the sampling chamber, and defines a fluid pathway between the inlet and the sampling chamber.