Compact Diaphragm Dosing Unit for Precise μl Volume Control
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Solution Overview
Problem
Existing dosing units for precise dosing of small amounts of liquids or gases in the μl range face issues such as high cost, lack of continuous delivery, imprecision, and inability to handle back pressure, particularly with syringe, peristaltic, and diaphragm pumps.
Innovation Solution
A compact dosing unit design featuring a diaphragm pump and two valves arranged side by side on the same side of a fluid housing, with fluid channels sealed by a flat seal and end plate, allowing for precise control and bidirectional flow, utilizing 2/2-way solenoid valves and a membrane pump with adjustable stroke, and a method for operating the unit with predefined pump cycles for calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If syringe pumps are used for precise dosing, then dosing precision is improved, but device cost increases due to electronic control requirements
Solution Approach 1:
The patent replaces electronic control systems with a purely mechanical pump mechanism. The dosing unit uses a mechanically actuated pump with a stroke-adjustable plunger that can be driven by simple mechanical means, eliminating the need for expensive electronic controllers while maintaining precise dosing capability through mechanical stroke length adjustment.
Solution Approach 2:
The pump mechanism is designed to be self-regulating through its mechanical structure. The stroke-adjustable plunger and valve arrangement create an inherent mechanical feedback system that automatically controls the dosing volume based on the set stroke length, without requiring external electronic control or complex feedback circuits.
2Measurement precision
If syringe pumps are used for precise dosing, then dosing precision is improved, but continuous delivery capability is lost
Solution Approach 1:
The patent implements continuous delivery capability through a reciprocating pump mechanism that can operate in continuous cycles. The pump alternates between suction and discharge strokes, with valves automatically directing flow to maintain continuous delivery. This mechanical oscillation allows uninterrupted fluid transfer while maintaining precise dosing through controlled stroke parameters.
3Adaptability or versatility
If diaphragm pumps are used for dosing, then bidirectional flow capability is achieved, but dosing precision deteriorates
Solution Approach 1:
The patent applies different design characteristics to different parts of the pump system. The pump chamber and diaphragm are designed for bidirectional operation, while the valve system and stroke adjustment mechanism are optimized for precise unidirectional dosing control. This localized optimization allows each component to excel at its specific function while working together for overall system performance.
4Reliability
If diaphragm pumps are used for dosing, then back pressure sealing capability is improved, but dosing precision deteriorates
Solution Approach 1:
The patent divides the pump system into functionally separate segments: a robust diaphragm pump section for handling back pressure and a precision valve-stroke adjustment section for dosing control. This segmentation allows the back pressure sealing function to be optimized independently from the dosing precision function, with each segment optimized for its specific role without compromising the other.
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 solution provides a highly accurate, space-efficient, and robust dosing unit capable of precise volume measurement independent of manufacturing tolerances, allowing for cost-effective production and flexible coupling options, while ensuring reliable operation in both flow directions.
Implementation Method 1
2/2-way solenoid valves
Implementation Method 2
membrane pump with adjustable stroke
Data Source
AI summary
The metering unit has a pump (20), two valves (18,22) and a fluid housing (12) with two ports, pump and valve channels, where a pump chamber is provided. The pump is mounted on the pump chamber. The pump channels communicate with the pump chamber and the valves. The valve channels communicate with the valves and the ports. The pump and the two valves are arranged one beside another on the same side of the fluid housing. An independent claim is also included for a method for operating a metering unit.