Flexible Liquid Bag Buffer Chamber Sealing for Diffusion Control
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Solution Overview
Problem
Generic discharging devices for pharmaceutical liquids suffer from liquid diffusion through the thin walls of dimensionally flexible storage receptacles into buffer chambers, leading to changes in active ingredient concentration due to unsaturated air in the buffer chamber.
Innovation Solution
A gas-tight protective housing seals the buffer chamber from the environment, or a capillary passageway for pressure equalization is used, and a pressure-balancing passageway with a valve opens to prevent air exchange and maintain saturation, reducing liquid diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the buffer chamber is open to the environment for pressure equalization, then pressure balance is maintained, but liquid diffuses through the receptical wall into the buffer chamber causing concentration changes
Solution Approach 1:
A valve is introduced as an intermediary component between the buffer chamber and the environment. The valve selectively controls air exchange to maintain pressure balance while preventing liquid diffusion by closing during discharge operations, thus resolving the contradiction between pressure equalization and substance loss
Solution Approach 2:
The system transitions from a static open buffer chamber to a dynamic system where the valve opens and closes based on operational needs. The valve remains closed during liquid discharge to prevent diffusion, and can open when needed for pressure equalization, making the system adaptive to different operational states
2Object-affected harmful factors
If a dimensionally flexible liquid storage receptical is used, then the receptical can be surrounded by a buffer chamber for protection, but the thin wall cannot prevent liquid diffusion into the buffer chamber
Solution Approach 1:
The valve acts as a mediator that controls the interaction between the buffer chamber and the environment. By closing the valve during discharge, liquid diffusion through the flexible receptical wall is prevented while the buffer chamber continues to provide mechanical protection
Solution Approach 2:
The buffer chamber creates a controlled environment around the flexible receptical. When the valve is closed, this environment becomes isolated, preventing external air from causing continuous diffusion and maintaining liquid concentration stability
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
Significantly limits liquid loss and maintains active ingredient concentration by preventing air exchange and ensuring air saturation in the buffer chamber, while allowing pressure equalization to prevent negative pressure buildup.
Implementation Method 1
liquid from escaping from the liquid storage receptical into the buffer chamber and thus from causing a change in the liquid located in the liquid storage receptical
Implementation Method 2
air to flow into the liquid storage receptical through a balancing passageway so that the ambient pressure is approximately re-established in the liquid storage receptical
Implementation Method 3
a capillary passageway for pressure equalization is used
Data Source
AI summary
A discharging device for liquids.The invention relates to a discharging device for liquids, more particularly for pharmaceutical liquids, comprising a delivery device (10), a liquid storage receptical (20) communicating with an input (10a) of the delivery device for storage of the liquid (30), and a discharge orifice (12) which communicates with an outlet (10b) of said delivery device,and the liquid storage receptical (20) is at least in part in the form of a dimensionally flexible liquid-containing bag (20) and the liquid storage receptical (20) is disposed in a buffer chamber of constant volume (42).To prevent air from escaping from the buffer chamber (42), provision is madefor the buffer chamber to be sealed by a protective housing from the environment (1) in a gas-tight manner,for the buffer chamber to communicate with the environment through at least one capillary passageway for the purpose of pressure compensation, orfor the buffer chamber (42) to communicate with the environment (1) via a balancing passageway for the purpose of pressure compensation, while a valve (70) which opens in dependence on the pressure differential is disposed in this balancing passageway.