Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
-----
Anodising bath air agitation
Q. Dear Sir,
I am working as a chemist in an anodising plant in Kolkata, India. We are going to construct a new anodising(Al.) bath. Please suggest me the technique to achieve good bath agitation.
Thanking you,
Abhijit kr. Datta- Kolkata, West Bengal, India
2002
A. There is no reason you can't use air agitation in an anodizing bath, and that is usually the most cost effective approach. There are any number of "how to" articles about air agitation in the plating journals and books, but thread 40886, "Agitation air sizing and calculations for plating & anodizing" should give you most or all of what you need.
Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. Dear Abijit,
To have uniform agitation you can either have a small twin lobe compressor . Alternatively if you have an acid circulating system using an acid pump then there are nozzles which could be fitted on the discharge line to ensure uniform acid agitation inside the bath.
Jothi RamalingamAbhinava Aluminium P Ltd - Chennai
A. We used air from a regenerative blower thru a sparger system. We later added a filtration system (which contributes a small amount of agitation) that allowed us to use the bath longer and have less rejects. I suggest both rather than just one.
James Watts- Navarre, Florida
2002
A. Hi Abhikit,
What James Watts says makes sense. A simple system. Use plastic pipe, i.e, PVC ... the layout, i.e., headers and laterals, will depend upon the tank length and width.
To start with use 1/8" dia holes (smaller ones tend to plug up during drilling) at say 12" centers ... and if you find, for instance, that the 'end' or 'ends' are not getting sufficient agitation and air bubbling, drill one slightly larger hole at the very end to relieve the pressure and get better distribution. ... you could take a bleed-off from your air compressor but then use a valve (diaphragm or needle) to control/reduce the flow.
For superlative mixing, go to the archives thread #7718.
Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
Q, A, or Comment on THIS thread -or- Start a NEW Thread