Air Contamination and Aluminum Particles

The oxidation of aluminium (which often appear to be black) can be prevented by anodizing.

I have a glass washer here that has four air knives. All are aluminum do a good job. They have been anodized. Now these are of some size and would be a bear to remove and clean if stainless. So I would take in consideration their size. As they will need to be removed and cleaned periodically. Most to all the contaminates comes from the air. I would be more concerned about filtering the intake of the blower.

Never heard of this. we used 3/5/10/15 HP blowers with Al impellers to dry PCB's during processing and it never caused us any problems. We built the equipment, so if there had been problems, our customers would have let us know, trust me. BTW, we switched from Paxton to Sonic air (usual disclaimer) blowers because they had fewer moving parts and a great warranty program. ozzb's idea about inlet filtration is a good one.

Good Luck!

Not "dirty" unless you have sand in air and removing material from the blade.

Anodize will provide a harder surface to prevent wear.

You don't need to anodize to prevent oxidize, the oxidized layer already prevent further oxidization.

Perhaps there is some confusion about 'dirty' aluminum. Most all food and pharmaceutical processing machinery is stainless steel because it is resistant to attack from the powerful acids, oxidizing agents and detergents that must be used at least daily to sanitize all the surfaces in order to comply with FDA requirements. Aluminum components will not endure long under those conditions. I amnot aware of any air moving system that would generate any wear in aluminum components or generate wear particles. Aluminum immediately forms a dense, air tight oxide layer whenever it is scratched. That molecular thin layer prevents any further oxidation unless it is mechanically removed or chemically attacked with a strong caustic or strong acid solution.

Yeah, there does seem to be some confusion as to the definition of the term "dirty" that I used. In fact, the title of my thread somehow was changed from "Is air contaminated by passing through aluminum?" to "Air contamination and aluminum particles". That isn't really my question. "Aluminum particles" are just one of the possibilities that I had mentioned. It isn't the exclusive way that I suspect that air passing over aluminum gets contaminated. I asked if there is something from the manufacturing process that may contaminate the air passing over it. Perhaps some kind of oil or solvent resultant from the forging or extrusion or casting process. Or if aluminum porosity attracts contaminents that may come loose. Those kinds of things. Actual particles of aluminum aren't the main suspect. That is more of a wear issue. I'm interested in whether air simply passing over aluminum continuously, such as passing thru an aluminum air knife, with some velocity, has more contaminents than that same air passing thru a stainless steel air knife... all other things being equal, except for the material.

The level of contaminents of which I speak are on the microscopic level, such as would be considered important in industries such as semiconductors and those types of things.

Corrosion due to chemicals and washdowns... that isn't what I'm asking about. Just clean air passing over/thru an aluminum component vs. a stainless steel component.

I apologize if I didn't make this clear in my original phrasing of my question.