Fraction Collector Fluid Front Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fraction collectors experience liquid spillage when switching between receptacles, which can lead to loss of valuable substances, health hazards, and contamination, and existing solutions either interrupt the liquid flow or result in air being drawn into the system, causing bubbles and contamination.
Innovation Solution
The method involves using an expandable chamber to accumulate liquid flow during the switching interval, controlling the fluid front to maintain it at a predetermined position, and then dispensing it into the next receptacle, utilizing a fluid front detector and control unit to manage the flow and prevent air entry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a valve is used to discontinue liquid flow during receptacle switching, then spillage is prevented, but liquid flow interruption causes diffusion of components and negatively affects chromatography performance
Solution Approach 1:
An expandable chamber is introduced as an intermediary between the liquid source and the receptacles. During receptacle switching, the chamber expands to temporarily hold the liquid flow, preventing spillage without interrupting the flow from the chromatography system. This mediator allows continuous flow maintenance while managing the transition period between receptacles.
Solution Approach 2:
The expandable chamber is pre-positioned and ready to expand before receptacle switching occurs. By having the chamber prepared in advance and expanding proactively during the switching interval, the system prevents spillage before it can occur while maintaining continuous flow, rather than reacting after spillage or flow interruption has happened.
2Object-affected harmful factors
If an expandable chamber is actuated to accumulate flow during movement, then spillage is prevented, but high accumulation rate may cause air to be drawn into the chamber forming bubbles
Solution Approach 1:
A fluid front detector monitors the position of the liquid in the expandable chamber and provides feedback to the control system. Based on this feedback, the actuation of the expandable chamber is dynamically adjusted to maintain the fluid front at a predetermined position, preventing air from being drawn into the chamber while still accumulating flow effectively.
Solution Approach 2:
The expandable chamber's actuation is made dynamic rather than static. The chamber expansion rate is continuously adjusted based on flow conditions and fluid front position, allowing the system to adapt to varying flow rates and prevent air intake while maintaining spillage prevention. This dynamic control enables the chamber to respond to real-time conditions.
3Productivity
If the dispensing nozzle is moving between receptacles, then fraction collection is enabled, but acceleration may lead to detachment of liquid drop
Solution Approach 1:
The system detects when a liquid drop is present at the dispensing nozzle in advance of receptacle switching. By identifying the drop's presence beforehand, the system can initiate the receptacle switching sequence at the optimal moment, allowing the drop to be properly positioned or transferred before acceleration occurs, thereby preventing detachment.
Solution Approach 2:
The liquid flow is maintained continuously through the expandable chamber during receptacle switching and nozzle acceleration. By keeping the flow continuous and the chamber expanded during the transition, the system ensures that liquid drops remain connected to the flow source, preventing detachment even during nozzle acceleration between receptacles.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 2c~2d
AI summary
A fraction collector comprising a liquid holding means (31) wherein it further comprises a fluid front control arrangement (43) arranged for locating the fluid front at a dispensing nozzle (5) and to control the liquid holding means (31) to keep the fluid front at a predetermined position.