# Vacume Filtering = Paint Drying...



## awbrew (Jul 31, 2012)

Hi guys, Little Giant 7-MD-Ck with a McMasters Eductor 1 Inch IN and 1.5 Inch out.. I still don't have all my 2 inch vacume line run with the drops... I have already tried it out a few times... while a great vacume pump, I can't help but get the feeling that Vacume Filtering is a lot like watching paint dry ...WVO makes a Centrifuge Filter its for oil (just search Centrifuge Filter on youtube) , and it looks like the bowl is aluminum, I know that isnt going to work with out some protective coating, like porcelian or some thing. or may be even getting a machine shop to mill a bowl out of stainless... But I like the ideal for a first filtration, to seperate the pgms while in a HCL/CL solution from carbon,Ceramic.. and again after the PGM drops... P.S. After installing the 20Ft of 2 inch PVC vacume lines, I will have more of a Vacume Reservoir... Will that make that much of a difference?


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## Palladium (Jul 31, 2012)

awbrew said:


> I can't help but get the feeling that Vacume Filtering is a lot like watching paint dry ....



My vacuum pump will suck the fleas off a cat at 20 yards!!!! I can't imagine running my refinery without it now that i use it instead of gravity filtration.


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## its-all-a-lie (Aug 1, 2012)

Apparently this guy has found a batch of instant dry paint!


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## NobleMetalWorks (Aug 1, 2012)

I'm just a little confused about what you are trying to do. It sounds like you are using an eductor as a vacuum pump. Are you also using the eductor for a fume scrubber?

If you are creating this system to just pull air, there are much easier ways to do it. If you are building the eductor for a fume scrubber, and using it as a vacuum as well, that is different. I'm using my fume scrubber as a vacuum also, however, for heavy duty jobs I also have a vacuum pump. The benefit of using the eductor vacuum is that any gases that might follow the air out are neutralized in the fume scrubber. You can protect your vacuum pump with a trap in line so that the gases don't ever make it to the pump, and thus corrode it.

Do you have pictures, or can you use a diagram to explain how your setup works? I'm not sure anyone can help you if we don't have more information to do so.

For gravity filtering, a friend showed me how to use strainers and the large coffee filters that are used in food service for the giant coffee makers. They fit perfectly in the plastic strainers, and the plastic strainers fit a 5 gallon plastic bucket perfectly. However, the filters are not fine enough to prevent metal particles going through, so I only use it when separating non pm material from solution, but it makes filtering much easier. I only use vacuum filtering if dealing with chlorides or filtering final sponge, etc.

Scott


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## awbrew (Aug 1, 2012)

Hi All, Thanks for the replies. Scott yes fume scrubber and vacuum as well. I posted some Pics, of my progress. I still have to finish plumbing to
carry the Vacume into the next room(2 in line). Also I already have the pipe to build the stack, and the wiffle balls to fill it, for packing. I also posted
a pic of the filter flask and filters being used. And Last I will build a small enclosure for nitric acid evaporation. I'm recovering PGMs from Cats
from my salvage yard. (HCL/CL method)(Own most of steves videos) (yes I have read Hoke 3 times And Alot of your post also, which I really like)...P.s. I will also be incorporating some vacume guages and pressure guages in to this final build of this system soon. So I can tell more about what going on... after I get back from Vacation. Thanks for your help and the time in advance..


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## awbrew (Aug 1, 2012)

Palladium said:


> awbrew said:
> 
> 
> > I can't help but get the feeling that Vacume Filtering is a lot like watching paint dry ....
> ...



Hi Palladium, Thats Nice... I was starting to get a little discouraged. I don't have the system finished yet. And their is no vacume guages yet, I will be changing that soon...


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## Palladium (Aug 2, 2012)

Looks like you got a nice little setup going there.


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## awbrew (Aug 2, 2012)

Thanks Palladium, Its been Slow comeing together. But its starting to take some shape...


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## Irons2 (Aug 2, 2012)

awbrew said:


> Hi All, Thanks for the replies. Scott yes fume scrubber and vacuum as well. I posted some Pics, of my progress. I still have to finish plumbing to
> carry the Vacume into the next room(2 in line). Also I already have the pipe to build the stack, and the wiffle balls to fill it, for packing. I also posted
> a pic of the filter flask and filters being used. And Last I will build a small enclosure for nitric acid evaporation. I'm recovering PGMs from Cats
> from my salvage yard. (HCL/CL method)(Own most of steves videos) (yes I have read Hoke 3 times And Alot of your post also, which I really like)...P.s. I will also be incorporating some vacume guages and pressure guages in to this final build of this system soon. So I can tell more about what going on... after I get back from Vacation. Thanks for your help and the time in advance..



Whatman GF/C glass filters have a very fine porosity. Try pre-filtering with a coarser filter, then use the GF/C to re-filter the solution. You will probably find that what you recover is not worth the effort, or the cost of the filter.


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## awbrew (Aug 2, 2012)

Thanks Irons, Any Suggestions? Or Wisdom...


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## 4metals (Aug 3, 2012)

Your setup vacuum setup looks good, there are a few questions though. To maintain suction in your piping the discharge into the drum must be extended into the solution in the drum, I can't tell if you did that from the picture. Second, a baffle in the drum will prevent the pump from sucking in air in the water from the discharge, without the baffle often too much air is sucked in, lowering the efficiency. I can tell you didn't add a baffle because you used a closed head drum.

The funnel you use classically uses a glass frit for the filters to sit on, these things always slow down to a painfully slow drip as they clog over time. Have you considered using a buchner funnel? 

Here is a picture of my porky hand holding a mini buchner that uses the same size filters you are using, I use them for assays.




and here it is working filtering PdDMG, love that yellow!


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## Irons2 (Aug 3, 2012)

4metals said:


> Your setup vacuum setup looks good, there are a few questions though. To maintain suction in your piping the discharge into the drum must be extended into the solution in the drum, I can't tell if you did that from the picture. Second, a baffle in the drum will prevent the pump from sucking in air in the water from the discharge, without the baffle often too much air is sucked in, lowering the efficiency. I can tell you didn't add a baffle because you used a closed head drum.
> 
> The funnel you use classically uses a glass frit for the filters to sit on, these things always slow down to a painfully slow drip as they clog over time. Have you considered using a buchner funnel?
> 
> ...



4Metals, Do you use a spacer between your filter and the Buchner Funnel perforations? I find that spreading the Vacuum out keeps things flowing much better, instead of having it localized near the perforations.


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## 4metals (Aug 3, 2012)

On a large Buchner I add a circle of fiberglass window screen smaller in diameter than the paper to keep the paper from only filtering at or close to the holes, it makes the filtration area much larger.

I have never done it on the mini buchner although it is do-able.


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## awbrew (Aug 3, 2012)

Hi 4Metals, Thanks for sharing the great pic of the vacume system. The Eductor is approx 2 to 3 inches in the watter. I haven't herd it slurping back, but I haven't run all my 2" Pvc with the drops. It wouldn't be a problem to extend it a little, I can still reach it through the center hole. As for the baffle, I had though I might be able to roll some thin Pvc sheet, about twice as thick as a business card. and thread it threw the center hole on top. Or another though was to cut a 1/4 inch channel across the top of the barrell and then insert a 1/4 thick rectangle sheet of pvc. Lowering it to the bottom. either way I would cut some holes in it for the water to crossover.I will try this when I get back from vacation.Thanks for the tip on the fiber glass screen, that will really help. 
On another note, I have a bigger buchner funnel, andI have used It with 5 coffee filters, On the first cleaning Filtration. But the Fine filter circles still stop up really fast on the second filtration. So the gap must still be great on the Microns between the two filters... I will cut some fiberglass circles for the small fine filters. 
The biggest thing Is when I only catch a small amount of pgms on a filter. I end up with a lot of the fiberglass circles that I need to remove for the pgm black. I scrape them as best as i can and then blend the dirty circles (seperate from the pgm black I collected). Next I add the blended fiberglass circles to a beaker with some HCL/CL and let set to put back into solution. I know I'm probably making this much harder than it should be...

I really like to read all the post you've written on the board. It shows you have spent much time explaining and demonstrating what ever thought your trying to get across... I know you have helped many...

Thanks Again...


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## awbrew (Aug 12, 2012)

Back From Vacation, I Caught a 51 inch Wahoo... Hes still alive In the pic, I'm on the left. I didn't have any gloves is the reason I didn't hold the fish by my self. Hes got a mouthful of razor sharp teeth.. Nathin on the right almost lost a finger on a dead one of these when he was 16, he said more people had been cut on handling dead wahoo than alive.


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