Inline Bubble Trap
with PTFE Membrane
Autoclavable
Effective
A bubble trap (degasser) is a device to remove the air bubbles from aqueous solutions inline or downstream in a fluidic system. Air bubbles in the fluidic flow can cause significant problems for many applications because the bubbles change the intrinsic physical properties of the microfluidic environment unexpectedly. This includes abruptly increasing the internal pressure, creating shear force variations, changing system compliance, or blocking small channels entirely.
Demo video of an inline bubble trap for air bubble removal for aqueous liquid flow.
The PreciGenome inline bubble trap can remove bubbles in the fluidic flow stream with or without vacuum assistance. Adding one is an easy and convenient solution to avoid the unintended introduction of bubbles into the fluidic system.
Bubble Trap Specifications
-
Effective removal of air or gas bubbles (not for dissolved gases)
-
Internal volume: 25ul, 95ul, and 300ul
-
Flow rate range: 0-60ml/min
-
Body Material: Peek
-
Membranes: 10um PTFE
-
Interface: 1/4″-28 Fittings
-
Flow Rate: up to 60ml/min for 300ul version (max);
-
Max Pressure: Up to 30psi
-
Easy membrane replacing to avoid contamination
-
No dead volume
-
Easy to install and place by PreciGenome design
Unit: mm
Bubble Trap Principle
The principle of the bubble trap is based on the interaction of two forces which are exerted on the air bubbles. These two forces are the hydrodynamic force induced by the fluid flow and the surface tension force induced by the trap walls.
When a fluid steam with gas bubbles flows through the trap, the bubbles are expelled through the hydrophobic air-permeable membrane, while it keeps the aqueous liquid inside the flow chamber without leakage.
Operation Instructions
1) For optimal bubble removal, the bubble trap should be mounted as shown in the figure, with both fluid ports positioned at the lowest point. This facilitates the movement of removed bubbles to the top of the air path.
2) Liquid tubing must be connected to the 1/4”-28 UNF female threaded ports. Inlet and outlet are interchangeable.
3) To obtain the maximum bubble/gas removal effect, a vacuum source can be connected to the vacuum port.
Work Modes
The bubble trap may operate in passive or active mode, depending on whether an external vacuum is applied.
1) Passive mode
In passive mode, the liquid flow goes through the bubble trap without external vacuum applied.
2) Active mode
In active mode, the bubble trap is connected to an external vacuum source, which allows the bubble trap’s efficiency to be maximized.
In microfluidic applications, the bubble trap is typically used with fluid going up to 10 ml/min. In other fluidic applications, the flow rate can be increased up to 60 ml/min when a vacuum line is applied and a model with 300 ul internal volume is used.
Example Application of Inline Bubble Traps
Why choose PEEK traps instead of PVC?
-
High abrasion resistance
-
Low moisture absorption
-
Outstanding chemical resistance
-
Low coefficient of friction
-
Excellent wear characteristics
The PVC trap is not autoclavable and is not suitable for organic solvents. PEEK traps are however compatible with most organic solvents used in fluidic applications.
How to select the models?
The main parameter for model selection is the internal volume of the trap:
25 µl, 95 µl, 300 µl.
A smaller internal volume traps less of the liquid solution inside the bubble trap, increasing solution usage efficiency. For expensive solutions, a trap with less internal volume is preferred.
These traps are also sufficient for bubble removal at low flow rates. However, if higher flow rates (>5 ml/min) are required, a larger internal volume should be considered.
What is the maximum pressure suitable for the bubble traps?
The maximum differential pressure that the membrane can be exposed to is 30 psi. The maximum inlet (positive) pressure is determined by the level of vacuum applied to the dry side of the membrane. For example, if a vacuum pressure of -12.5 psi is applied to the dry side, the maximum inlet pressure should be less than 17.5 psi.
How to improve the degassing effect?
To optimize bubble removal, the pressure difference across the membrane must be large. If the pressure difference is insufficient, a vacuum can be applied to the vacuum port. Alternatively, back pressure may be applied by increasing fluidic resistance at the outlet port.
De-gassing is also affected under positive pressure on liquid flow ports. It is not possible to pull liquid through the unit under vacuum as this would introduce bubbles into the fluid. However, the vacuum line on the dry side of the membrane can applied up to -14.5 psi in active mode. In practice, if -5 psi is enough to remove the bubbles from solution, further increasing the pressure would not lead to drastic changes. For more modest vacuum output, PreciGenome offers the portable vacuum pump PG-MP1 for bubble traps.
What are the typical flow rates suitable for the bubble trap?
The typical flow rates used in the bubble trap are up to 2 ml/min, but up to 6 ml/min can be achieved if few bubbles are present in the liquid. Up to 60 ml/min can be achieved for a high-flow trap when a vacuum line is used. Generally speaking, it is easier to remove bubbles from lower flow rates.
What is the solution compatibility of the bubble trap?
The bubble trap can only be used to degas aqueous solutions. If other liquids are used, chemical compatibility with the PEEK enclosure and PTFE membrane must be considered and thoroughly tested.
What is the lifespan of the bubble trap?
Lifespan of the membrane filter highly depends on the fluid used. For pure water, the lifetime may be several months or years, though buffer solutions will reduce this. It is recommended to use de-ionized/distilled water to flush the unit after use to prevent salt crystals forming from residual buffer.
To reduce likelihood of contamination from the membrane, it’s highly recommended to change membranes if the bubble trap has not been used for a long time, or if it has been used for different solutions.
How to clean the bubble trap?
Aside from flushing with water, bubble traps may be cleaned with ethanol. 70% or higher ethanol can be used, especially in sterile conditions. In this case, it is important to flow water through the bubble trap once finished to remove traces of ethanol.
What are the differences between bubble trap versions?
EZMount version: rectangular base with mounting holes. Easy installation, easy mounting.
Standard version: round base, no mounting holes.
Documents:
-
PreciGenome bubble trap datasheet
-
PreciGenome bubble trap user guide
Customers Trust Us
Some of Our Customers
