Think & Tinker, Ltd.
P.O. Box 1606, Palmer Lake, CO 80133 Tel: (719) 488-9640, Fax: (866) 453-8473 Sales: Sales@thinktink.com, Support: Support@thinktink.com |
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Think
& Tinker Ltd. SkypeMe at "thinkntink" |
Drilling an air bubbler manifoldAir agitation, while easy to implement, presents a few challenges to the tank designer. Foremost among these is providing the right amount of VERY clean, dry air to the sparger. Generally speaking, better agitation is achieved if the air injection results in a uniform "curtain" of large bubbles delivered at 2 CFM (cubic feet per minute) per square foot of solution surface area. Unfortunately, large bubble generation usually translates into a requirement for a high volume air source such as a regenerative blower or high capacity air compressor. In the case of a process tank for PCB prototyping, the surface area is usually less than 2 square feet, so a fairly small compressor can be employed if we use a simple trick to generate large bubbles while minimizing air consumption.Start making the air sparger by drilling the two sections of PVC pipe as follows.
When assembled into a sparger, the holes face inward towards the PCB and are rotated 45o below horizontal. Air flowing through the 0.040" dia. holes collects in the 1/8" dia. cavity until a 1/4" to 1/2" diameter bubble forms and breaks away. This process continues, forming a turbulent stream of relatively large and "active'" air bubbles. Without the downward facing cavity, the bubbles formed would be no more than 3/16" in diameter and unable to adequately disturb the process solution. |
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