Linked is another thread asking a question about negative ion generators. I don't want to hijack that thread so I'm starting my own.

I run a wood burning laser engraver, low power (7.5 watt LED laser). It produces smoke. The work station consists of a table top with holes. Covering the table top is a lift off cover. When I lift it off it's full of smoke. Hence, the purpose of the holes. I've set up a filter to draw down and capture the smoke but it depends on filters which are not washable or reusable. So it will be going through a lot of filters.

In the linked thread the question is raised about negative ion generators. So I've been looking for something superior to the setup I now have going. Money is not a major concern but I don't want to spend thousands of dollars. So what little I know about ionizers is that they can remove smoke from the air. Yes, they do make the smoke stick to the plates but the plates can be cleaned. That is to say it's not a one time use and throwaway item.

So there's this set of stainless steel plates approximately 2 1/2 inches wide (63.5mm), 18 gauge by 24 inches (609.6mm) long; 18 plates. I've found a few ion generator modules on line but they have five spikes (pointed tips are important for ion emission into the air stream). I'm thinking about building my own generator. With such a large surface for smoke capture, I'm dubious about the idea that a small ion generator would have enough power to make such a large set of plates effective in absorbing the smoke prior to exiting the chamber.

Among the considerations is use of a MOT (Microwave Oven Transformer) with the HV coil intact (1KVAC). Then use the HV diode to rectify the charge. But the 18 plates are spaced approximately (from memory) 4mm apart. Unless all plates are wired in common I could be building a potentially deadly high voltage capacitor. So don't think I'm being reckless in this endeavor. I haven't put anything together yet other than the plates which were once used to investigate HHO generators. No, we're not going into HHO generators, this is a leftover from that endeavor. But I think it might be possible to use the plates as smoke arrestors in a two foot ABS tube.

So does anyone know anything about a good ion generator module? Or perhaps on the construction of my own ion generator - without killing myself!

 

Electrostatic precipitation was a common air cleaner option at one time. Those devices may still be commonly available.
As for high voltage being a hazard, certainly it is, that is why there are all sorts of warning labels. For those who ignor the adequate warnings,"Natural selection awaits you."

 

Electrostatic precipitation was a common air cleaner option at one time. Those devices may still be commonly available.
As for high voltage being a hazard, certainly it is, that is why there are all sorts of warning labels. For those who ignor[e] the adequate warnings,"Natural selection awaits you."

Not to mention an automatic entry in the Darwin Awards competition.

 

"Natural selection awaits you."

Yup! Love NS. Worst invention ever - warning labels.

Not to mention an automatic entry in the Darwin Awards competition.

Somewhere I had a Darwin Award certificate. Will have to see if I can dig that up.

 

OK, I think I have that award on an older hard drive, one I haven't yet retrieved the information from.

found this:
https://www.cnet.com/science/darwin-awards-studdy-suggests-men-a-lot-less-intelligent-than-women/

 

 

OK, less commentary, more advice / suggestions please.

 

OK, less commentary, more advice / suggestions please.

I already made my suggestion, prior to my comment.
Consider the electro-static paint application process, where the spray all rushes onto the work-piece. Almost no over-spray.

 

From my research, 1KV won't be enough. Honeywell "electronic air filters" use 8KV. Of course, a lot depends on spacing and airflow rates.

You might look at the Harbor Freight HEPA shop vac filter. The bore is ~6", so it's easy to connect to a piece of 6" duct.

And it's washable with water and relatively cheap.

 

I REALLY do NOT like links popping up as a post. In fact , I see it as really obnoxious.

 

To what links do you refer?

 

You might want to consider salvaging an HVPS from an older laser printer that uses a corona wire to charge the paper. Something like the LaserJet 4 series, for example. If you can find one it should be dirt cheap or free.

Newer models use a ”PCR” (Primary Charge Roller) and subsequently a lower voltage—something around 1kV compared to the corona wire models 5kV to 7kV.

 

ou might want to consider salvaging an HVPS from an older laser printer

Of all the printers I've ever dismembered I've never taken a laser printer apart. I'm totally unaware of any HVPS. I happen to have an old retired LP. I may have a look inside that.

From my research, 1KV won't be enough. Honeywell "electronic air filters" use 8KV. Of course, a lot depends on spacing and airflow rates.

You might look at the Harbor Freight HEPA shop vac filter. The bore is ~6", so it's easy to connect to a piece of 6" duct.

And it's washable with water and relatively cheap.

View attachment 326498

Washable - that I like. But dragging a shop vac into a Home Show, which is where I'll be featuring some of my laser etching work, may be a bit noisy. Neighboring vendors may not like all the noise. But I'll look into it for sure.

Oh, and thanks for the heads up on the KV thing. I have to agree with Bill, a link would be better than a screen capture.

 

Looking at the filter:
https://www.harborfreight.com/hepa-...er-vacuums-five-gallons-and-larger-59554.html
My main concern is smoke entrapment. The two issues that will probably get me kicked out of the show is smoke and noise. There is a possibility I can modify the exhaust fan I'm using to extract the smoke from the laser chamber. If not - I have an old exhaust fan from a stove that might be easy enough adapted to filtering out the smoke.

 

I have to agree with Bill, a link would be better than a screen capture.

No, @MisterBill2 objects to posting links and has stated in the past he won't look at them.

 

But dragging a shop vac into a Home Show, which is where I'll be featuring some of my laser etching work, may be a bit noisy.

I didn't suggest using a shop vac. I suggested discharging your exhaust fan through this filter. I'm sorry if my intent wasn't clear.

The bore is ~6", so it's easy to connect to a piece of 6" duct.

You do of course have to block the other end of the filter, but it comes with a "lid" that you could glue on.

But since you object to posting pictures that show instantly what I'm talking about, and @MisterBill2 objects to posting links, I'll just STFU now.

 

I'll just STFU now.

Please don't. I value your input.

No one asked for pictures. I'll shoot a few and post them shortly.

 

OK, here's a few.

Above: Laser Bed

Above; Laser Bed and filter port

Above; Filter exhaust

Above: Filter receptical; 6 1/4" wide to inside rim.

Above: New, In use, Used. Attempted to wash - no luck.

So I've been thinking about building the ion chamber to collect the smoke. Even when you think you're not making smoke - you are. Makes my throat hack.

 

Finished burning this 10 minutes ago. Still have to make the frame, but I have the plate (etched insert). Removed contact information.

Going to Harbor Freight. Then Lowe's. Wife wants some clear paint to protect her new garden bench seat.

 

Of all the printers I've ever dismembered I've never taken a laser printer apart. I'm totally unaware of any HVPS. I happen to have an old retired LP. I may have a look inside that.

An HVPS is basic to the operation of a laser printer. It is used to charge up the imaging drum before exposing it using the laser. The laser is used to depolarize the areas of the drum that shouldn’t get toner. The photosensitive coating makes this possible.

The drum charging can either be with a roller that makes contact with the drum or a corona wire that works across an air gap. The latter type require considerably higher voltage because of the air gap. Locate the connection to the corona wire and you will find the HVPS (which might be integrated with the general purpose PSU).

Some printers (maybe all, but I don’t know) use PWM to control the voltage on the wire—this might be handy for dialing in the ideal voltage. I also wonder if charging the air, then giving the collection plate an opposite charge would let you work with lower voltages and count on the differential.

By the way, all of these things can generate O₃ (ozone) and you can sometimes smell it when an older, corona wire type printer runs. Printers include ozone filters, and they do last for the expected life of the printer but just bear that in mind since O₃ is bad for just about everything being such an aggressive oxidizer.

If you can arrange it at all, it would seem prudent to exhaust the scrubbed air to the outside. Thanks to a greatly increased interest in… umm… indoor gardening, there are very good, not very expensive inline blowers that work with standard 4” flexible duct (like drier hose) which is available in heat resistant version. There also exist large activated charcoal filters with 4” inputs that are used to remove the potentially intense odors of the... umm… garden which might be good for your setup.