With micro-metering valves installed on each output, the SAI™ Model 5 Bubble Generator provides precise control over the bubble generation process. It is a compact and unique tool for visualizing complex airflow patterns. Helium-filled, neutrally-buoyant bubbles of uniform size, adjustable from 1 mm to 4 mm in diameter, can be generated simultaneously from either one or two bubble outputs.
The bubbles are capable of tracing intricate air motions without bursting or impacting on objects within the airflow and have a lifespan of 1-2 minutes. The unit is designed for simplicity of operation in any location where helium and compressed air are available.
The console may be ordered with either one or two outputs. If purchased with a single output an additional output can be easily added later to double the bubble production.
Within the case, the control console is on the left and the Mini-Vortex Filters with Plug-In Bubble Heads on the right. Space is also provided beside the filters and in the top cover for storage of bubble wands and flexible tubing. These items are used to duct the bubbles to the area of flow that is to be visualized.
Compressed sources of helium and air are connected from external supplies to the inlet ports located in the top row of the console. The large fitting in the center of the of this row is the fill port for the bubble film solution, (BFS). The BFS is held in a storage cylinder mounted under the panel.
The panel is laid out for easy identification of the fittings and valves. The columns are labeled "HELIUM", "BFS", and "AIR". Below each label is a toggle valve for turning the corresponding constituent on and off. The next two rows consist of metering valves, which are labeled "Out 1" and "Out 2", these valves control the flow rate of the constituent the Plug-In Head. Vernier scales are incorporated on the handles of the metering valves to enable the user to reproduce the desired flow rates very precisely.
The whole unit is easily disassembled for general cleaning, maintenance or repair.
The Plug-In Head and Mini-Vortex Filter in combination represent the most advanced means for high generation rates of neutrally buoyant bubbles within a compact space. The Plug-In Head consists of a concentric arrangement of two hypodermic tubes attached in a cantilever fashion to a cylindrical manifold base. Within the Head, helium passes through the inner hypodermic tube and the bubble film solution passes through the annulus between the inner tube and the outer tube to form the helium-filled bubbles at the tip. A much larger, concentric jet of air, in turn, blows the bubbles continuously off the tip as they are formed.
Some of the bubbles generated by the head are too heavy and some, too light. The Mini-Vortex Filter serves to remove these "bad" bubbles. It is a clear cylinder which utilizes the jet of air from the Plug-In Head to set up a rotational or cyclonic motion inside. The resulting radial forces then cause the bubbles which are not neutrally-buoyant to separate out. Bubbles that are neutrally buoyant then flow up and exit the outlet tube. Flexible tubing with a wand attachment can be connected to the end of the outlet tube to so as to direct the bubbles to the area of interest.