Closed Wick Fluid Reservoir for Contamination-Free Particle Counting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing condensation particle counters face issues with contamination and measurement errors due to vented reservoirs allowing air contact with working fluid, leading to problems like vapor lock, contamination, and false particle counts.
Innovation Solution
A closed, collapsible, unvented reservoir system is used to store and transport working fluid, which is pumped directly to the wick, with sensors monitoring fluid levels and preventing overfilling, ensuring contamination-free operation and accurate fluid delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a vented reservoir is used to store working fluid, then air can contact the fluid for simple design, but contamination occurs and measurement errors increase
Solution Approach 1:
The reservoir system is segmented into a sealed fluid storage compartment and a separate wick chamber. The working fluid is contained in a sealed vial that is inserted into the wick chamber, physically separating the fluid storage from the atmospheric environment while maintaining functional connection through the wick material.
Solution Approach 2:
A hydrophilic wick material serves as an intermediary between the sealed fluid reservoir and the particle counting chamber. The wick absorbs and transports the working fluid from the sealed container to the saturation region without requiring direct atmospheric contact, thereby preventing contamination while enabling fluid delivery.
2Ease of operation
If a vented reservoir with gravity feed is used, then fluid delivery is simple, but vapor lock and contamination occur
Solution Approach 1:
The gravity feed mechanism is replaced with a controlled pumping system. A pump actively delivers the working fluid from the sealed reservoir through the wick material into the saturation chamber, providing precise control over fluid delivery rate and eliminating the harmful effects of vapor lock associated with gravity feed systems.
Solution Approach 2:
The fluid delivery mechanism transitions from passive gravity-driven flow to active pump-controlled flow. This parameter change enables precise control of fluid delivery rate, ensures consistent saturation conditions, and prevents vapor lock by maintaining positive pressure in the fluid line.
3Ease of manufacture
If working fluid is stored in contact with air, then storage is simple, but shelf life is reduced due to contamination
Solution Approach 1:
The working fluid is stored in a sealed, air-tight vial that creates an inert environment isolated from atmospheric contaminants. This sealed storage configuration prevents oxidation, microbial contamination, and evaporation, thereby extending the shelf life of the working fluid while maintaining its chemical integrity for extended periods.
Solution Approach 2:
The working fluid is extracted from direct contact with the atmospheric environment and isolated within a sealed container. Only the necessary amount of fluid is introduced into the system through the wick material, minimizing exposure to contaminants and preserving fluid quality throughout its service life.
4Productivity
If a pump system with vented reservoir is used, then fluid can be delivered, but false particle counts occur due to contamination
Solution Approach 1:
The working fluid is pre-loaded into a sealed vial before insertion into the wick chamber. This preliminary sealing action prevents contamination before the fluid enters the particle counting system, ensuring that only clean fluid is delivered by the pump and preventing false particle counts caused by contaminated droplets.
Solution Approach 2:
The hydrophilic wick material acts as an intermediary filtration barrier between the sealed fluid reservoir and the particle detection zone. The wick selectively absorbs and transports only the intended working fluid while blocking atmospheric contaminants, thereby protecting measurement precision while maintaining productivity.
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 contamination-free, accurate, and reliable supply of working fluid, reducing false counts and extending the usable life of the fluid, while maintaining measurement accuracy and preventing flooding.
Implementation Method 1
A wick delivers the working fluid to an outer surface
Implementation Method 2
A condensation particle counter uses the principle of supersaturation to promote droplet growth on a surface of a suspended solid particle
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system includes a polymer bag, a fluid network, a saturation block, and a wick. The polymer bag has a sealed envelope and a fitment. The fluid network is coupled to the fitment. The saturation block has a fluid inlet coupled to the fluid network and has a wick chamber. The wick is configured for disposition in the wick chamber.