I recently had 2-4" resin towers fail and leak Purolite into my biodiesel. Failure was due to screens coming loose on a section and sagging, most likely caused by not have flat surfaces.

But due to this failure I realized the design of the towers don't make for easy repairs. So with this in mind I came up with this design and wanted to get your opinions. Think the design is pretty self explanatory.

Be gentle!

Thanks

Jerry

resin_tower.png (48 KB, 90 downloads)

The PVC is a bad idea from the get go. It has been shown to split just from the chemistry of the biodiesel and resin together.

Metal, stainless steel (yeah right...) and FRP (fiberglass reinforced polyethelene/polypropolene) are good choices. Mine are FRP and have been going strong since the beginning of last year non stop.

Ok I am a pipefitter and I will be "gentle" hahaha.
First, you choice of materials "PVC" not good! The Bio will attack it in a short amount of time so this in itself will cause a failure. But the closet flanges are not designed for pressure, your idea uses what we call draw rods which would work with "pressure flanges". If you notice the closet flanges are very thin as you tighten the rods to seal the unit the flanges will warp and make leaks, the more you tighten the more it warps the more it leaks.

I know this doesn't help your situation but I use 8" pipe with welded flanges, this method has been foolproof however I understand not everyone has access to these materials or the know how to work with them. What I would suggest is you check out Legal Eagles set up, that has worked well for him and maybe more user friendly for you in getting the components.What ever you do will cost you money but I would not want to see you spend money on something that has a high probability for failure. I hope this helps if you need pipe advice feel free to ask I have been at it for 30 yrs.

Thanks for the inputs. I do have to say that the choice of PVC is due to one of cost and accessibility. But I have noticed numerous individuals here building their systems from similar PVC. Is the failure risk due to the increase of volume by resin and lack of expansion space? Wouldn't the use of PVC 40/80 help to mitigate the failure in this particular use and insuring that ample space is left in for expansion? Heck I see plans and complete systems for sale using PVC!

PLEASE don't take these questions/statements as discounting your knowledge or experience! Just trying to put it all together when I see to the contrary.

51fitter thanks for clearing up the use of pressure flanges over using the closet type. Legal, can you send me a link to your page that shows your tower setup? I would be most appreciative.

Thanks again!

Jerry

If you are using a gel type resin I would not even consider PVC. If you use Thermax, which I use, I would at least give it a try. I have been using PVC since May of last year. No problems to date. I am not saying it won't happen -- only that it hasn't.

Jerry,

So if you do go with the pvc, it might be a good idea to have some sort of secondary containment ie


an open top drum with the columns setup vertical, so if there is a leak....

Jerry
The use of PVC may not be a complete failure in the begining what typicaly happens is the bio works on it over time and makes it brittle.I mentioned in my first post that the bio would attack it in a short amount of time, to me when building a pipe system anything failing in the range of 2 years or less is a short amount of time. This is not the only substance that has this affect on PVC.You are correct that many set-ups are made from PVC and I'm sure some are holding out but it has been mentioned in other post about the failures.And if you look at the bottom of Legals Post you can see his links, click on them to see his gear.As a side note people who know me would tell you I over-build things but at the same time I usually don't have to do things twice. If you really want to give the PVC a go I can walk you thru some design idea's so you don't use the wrong fittings "closet flanges" And I can help you get PVC pressure fittings by directing you to commercial supply houses in your area and arming you with the correct trade lingo. But I will tell you that when you get into PVC pressure fittings the cost will go up and most of what I will recomend is not at Home Depot or Lowes. This is why I was steering you away from PVC because to me you eventually will run into problems, I just can't predict when that will be.

And like I said earlier I tend to over build but I know it will last.If you decided to build a system out of PVC with my coaching and it failed next year I would feel bad that you threw good money after bad! But only you can make these decisions. Hope this helps.

We use iron pipe for most of our processor, a little plastic tubing for the methoxide introduction so we can see the flowrate. I would never build a system with PVC and cringe when I see ones for sale made from that.

Jerry, here is a whole thread of when I first built my towers.. I loved the pvc tower but the only problems I had was the BD would eat up my red plugs, Im no plumber so I dont know the name, in about 2 weeks. Twice I lost a lot of BD because as soon as they were weak the pressure blew them out.. the screens and filters were very easy to do.
I only used woodchips in mine and Thermax in the steel one. I built my whole pvc tower for around $50..
Ill just let you read the thread because all these awesome experts gave a lot of great advice on it..
Here is a better look at my redesign of the tower. I dont use it anymore. If you were close I would give it to you to revamp..

towers

Thanks for the links and tips Lisa! I didn't even think of using the rubber coupling/union things. Yes I know this will most likely fail sooner than later, but as I indicated earlier this will get me going til I get with my buddy to weld up some towers.

I can't wait to have my towers back up and running! I just brewed a 8 gallon batch and doing water wash until I have my towers back on line. WHAT A PAIN! Seems like I've gone through 20+ gallons of washing and have at least another 10 to go! I really miss having finished bio in a day!

OH...as a lark I tried entering in my '98 VW New Beetle in the government Clunker Trade in (C.A.R.S) program. LOL!!! : ) My car is to fuel efficient to qualify!!

Thanks to everyone!! Will report back with updates and pics.

Jerry

I just finished building a 4"PVC system (two towers) from plans I bought from Houston Biodiesel. I modified them in two ways to suit my needs. First, I built a screen into both the top and bottom of the towers since I wanted to flow bottom to top rather than top to bottom. Second, I secured the stainless screens to sheet metal "O-rings" with JB weld before sandwiching them between O-rings of PVC in hopes that they would hold up better to the weight of the BD soaked media. I using aspen wood chips to start in both towers and running the first batch through it as I write. I will report back results. I did take a sample from the out put and did a shate test on it and it came out ok. I'll do a shake and soap test on the batch when it finishes.

I too chose PVC for the low cost and ease of use. I, however, like the idea of using iron pipe should I decide to go the resin route, as long as it's not too expensive.

You may find the wood chips to be sufficient. I let my last two batches settle for about 3 weeks and tested for soap. It was nearly undetectable. I went ahead and ran them through the wood chips anyway, filtered and tanked up.

see new post "chip one online"

Funny, I too had a big question about just having the steel mesh supporting all the weight of the Bio and resin and or chips. So much so, I too bought the Houston Bio Plans hoping they had some solution - nope - just the mesh glued between rings. However I lucked into a great solution.

At my local Lowes, when shopping for PVC column parts, I found a PVC drain which the top (drain part) is the same size as 4" Pipe and the supporting shaft fits outside 3" pipe. This last statement is the important part as it means it also fits very nicely just inside 4" pipe! So finally build something that would support the mesh!

The assembly From the top down:

1) A 4" ring with one end from the factory. This end will face down toward the mesh. ( I had to cut this.. about 1 inch thick)
2) 4" stainless steel mesh
3) This special drain

a) Sand off the raised writing on the top face of the drain.
b) JB Weld the mesh between the ring and top of the drain.. I recommend using clamps overnight.
c)After 24 hours or so, sand down the outter edges, where all the extra JB weld has dripped, making the surface all the same level.

4) This "mesh assembly" fits into a Threaded clean-out with 4" PVC fitting (same as 4" pipe size)
5) Looking from the side, now what you have is a threaded clean-out with about a 1" extension at the top. Now use a normal coupler to join this to your long 4" pipe.

I to thought about how to repair one of these, but with all the JB weld and PVC glue, you basically are making a disposable column. I once cam up with a design that uses 4 extra clean-out fixtures so that you can screw off each screen section, but... it added another $28 to each column and well, as they approach the $100 mark, and I worry so much about repairability, better then to make them out of steel. So I just scrapped the idea.

Also, I apologize for not having the name and part number from Lowes. I will be back there for returns so I will post it soon. (I mention Lowes a few times because I saw it there, but never at home depot, but they might have them as well.)

Doug

Two quick questions.

1) Where can I get stainless steel mesh from?

2) Are people using black drain PVC or where are they finding white 4" PVC.

Thanks
Doug

ss screens from Houston Biodiesel and why PVC should be available from your local hardware store