500 lt tank as a Processor

[K.H]

One for Tony really
What are you doing with the bolt down base/lid?
I guess running a GL you will seal it for good when you've finished?,i need to keep mine removable for dewatering and playing.
My ideas so far are changing the bolts to brass which will make it a pain to remove or welding a bar accross but under the opening and having a threaded bar coming off that up the centre,then solder a brass nut into the existing 1 1/4" outlet,then i could just spin the lid on and off,any views?
Picked up the fittings i need yesterday 2 x 2" sockets for the pump,2 x 1" sockets breather and oil in and a 1/2" socket for a thermometer,off tomorrow morning to get some 2" box section for the legs,so out with the hole cutters this weekend!

[Tony]

I was going to cut the legs off the tank, flip it upside down, and weld new taller legs on.

I have an ikea plastic cutting board to cut into a ring to make a big gasket for what will now be a top access hatch (since it's upside down!).  If you were really worried about leaks you could weld it in place but it's nice to have an access port for fitting things inside

Then i was going to open up the hole at the bottom (was the top bolt securing the bladder) and weld in a 2" mild steel nipple from BES.

The 1 1/4" pipe comes in 7.6m lengths so I'll have loads left over, which would make suitably strong legs.

[Julian]

Feeling a bit left out of this thread!  I haven't got a 500 lt tank!

What I have got is A4 sheets of flexible, foamed PVC, about 3mm thick ... any use to you guys as gasket material?  Haven't tried it on the processor, but it seem to be ok with bio on tank connectors on the settling tanks.

[Tony]

Julian if you want one Mark seems to have a fairly regular supply of them

We're no longer constrained to 250l batches so why not go big and save the hassle of doing it very often?

[Julian]

I was round at Marks the other night and saw the one he had, it's enormous.  My shed is only 6 foot square and about 5 foot at the eves.  If I put that in there I couldn't get any thing else in, hence my quest to go to a square processor and associated tanks and hence the interests in your tank.

What about the PVC?

[Tony]

I am quite curious as to your PVC - is it very squishy or quite firm?

[Julian]

All the girls ask me that!

It's fairly firm I guess but it's relative to the area you're compressing.  It's very good at filling nooks and crannys and will compress down quite a bit.

[Tony]

The rubber liner of these expansion vessels had the neck clamped by this flange.  The material was quite thick, and there is a rolled rim that protrudes from mouth of the vessel's hole.  I think that was designed to clamp the neck in place.  So I think we need something quite thick to seal it (can't just use gasket sealant here!).

I think we'll have to experiment with a few options to find a suitable seal (or at least verify if your PVC is the right sort of width!)

Quite curious as to why KH wanted to swap the bolts for brass ones - was that to avoid sparking if removing when methanol rich?  I really don't see that being much of a risk.

[K.H]

Yes brass for non sparking,they only cost a few pence anyway.
A gasket sealant would be no use to me,i will be removing the lid every batch so something like Julians pvc could well be the answer but i still want it to be easily removable.

[Julian]

I know exactly the sort of accumulator tank you're describing, we used to use them in the marine company I worked for.  We had batteries of smaller ones coupled to a good old Mono pump and a few pressure switches and things.

If I remember the bladders were Neoprene or Nitrile,so not perfect for submersion in bio, but as a gasket might be OK.  Why not cut the balloon part off and use the neck as the gasket?

Happy to post a piece of the PVC or I can bring to Chugs, if you can wait that long.

[K.H]

Chugs would be great Julian,think i might have to fish the bladder out of the wheelie bin in the meantime

[Julian]

You've thrown it away ... and there's me thinking you'd be fashioning it into some rather fetching rubber garment!

[Tony]

Yes brass for non sparking,they only cost a few pence anyway.

Makes sense - where do you get them from?

A gasket sealant would be no use to me,i will be removing the lid every batch

You could oil one surface or use clingfilm to stop a gasket sealant from setting sticking - maybe a RTV silicon would be appropriate?

I suppose the nice thing would be to replace the steel with a glass lid so you can see inside and watch things like spray nozzles working correctly.  These are a bit pricey but something like that?

http://www.trinity-portholes.com/sections/37/weld-in_trinity_portholes/

Could weld it onto a flange so it can still be removed?

I take it you're planning on using your existing monster pump on this new vessel then Keith?

[K.H]

I will take some photos tomorrow,it will make talking about things easier
Brass M bolts are available locally but i noticed they are also on ebay,those portholes are very tempting,imagine the slagging off i would get if i fitted one 
Going to flip it the same as you and use my existing 2" pipe work and pump but ive got to quieten it down,thinking of boxing 3 sides in and maybe fitting a comp fan to help cooling,funny thing is if i slightly close down the valve to the pump or open the sight tube it runs a lot quieter,the valve on the pipework from the pump makes no difference?
Only other headache is sorting the control box,ive got quite a few of the bits needed just need to get it put together,but then i had the parts when i built the present one but i just put plugs and leads on everything so i could make diesel asap,its too easy to let that side of things slide

[Tony]

Know what you mean, my control panel hasn't transpired yet even though I've got most of the bits.

I'm putting IEC connectors on the pumps and commandos on the heaters so can always connect them direct to the mains to keep the fuel flowing if needed - though I'd be very nervous making batches without heater protection.