Biopowered - vegetable oil and biodiesel forum
Biodiesel => Biodiesel equipment => Topic started by: K.H on May 07, 2012, 08:29:05 PM
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Couple of questions on the pressure switch as i need to get around to fitting one
i assume the pipe inside has to go down to at least the imm elements? and is there any particular reason for the outside pipe been 22mm?
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I've fitted a WMPS to my processor, but I'm not very impressed with the way it operates and haven't bothered to wire it up.
If I was starting again from scratch, I'd go for a float switch.
However, 15mm should be fine. If you file/turn off the stop in a 15mm fitting and use a couple of 'O' rings in place of the olive, you can make it adjustable (assuming your pipe enters from the top of the tank).
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Blast,ive put a socket on the side high up,it would be easy to fit a float switch tho
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What size is the socket?
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1/2"
The 3/4" sockets / sintered exhausts,do they need a non return or anything on them to stop the bio seeping out?
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Ooo, if it's quite a long socket then you'll need a very slow bend on the 15mm pipe to get it in!
Don't know if it's a "BRTP" dewatering devise, I believe others are doing it. On mine the tank penetration is pretty much where yours is. From there I ran a 15mm pipe (although for dewatering there's no reason why it can't be smaller, *but see the note below) via an elbow up vertically to a point higher than the maximum fill level and stuck the needle valve on the end. After the valve use small bore plastic.
The little compressor I use has no tank, just a relief valve, so I tend to close the needle valve whilst it's still running to trap air in the pipe, then turn the compressor off. With the piping arrangement above, it shouldn't be a problem if bio/oil runs back up the pipe anyway, it can't go anywhere and will get blown back out next time it's used.
* Just a little hesitant to publicise the idea too widely, because if used for demething I'm sure it'll create a flammable atmosphere within the processor along with the likely hood of escaping fumes. Added to which, small bore pipe work will increase the velocity of the air and just possibly give rise to static, this, coupled with the flammable atmosphere could be rather risky.
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Keith the 22m bit is unimportant, use what you've got. Funnily enough I recently had a conversation with mark about using brake pipe (narrow bore) as the sense tube but we think it might need 12mm or 15mm to get the pressure to trip the switch.
We think that the wider the bore in the liquid the sooner the switch will trip as the liquid rises (less tube immersed). It might work with smaller bore but you'd have to have it deeper to get the switch to trip, if you see what I mean?
I'm planning on putting mine through a fitting on the very top so the tube drops vertically into the processor for adjustment purposes. And also doing the same with another tube for Julian's demeth booster (but only using a fish tank pump for the air suppply. But now Julian has me worried about flammable atmosphere and static....
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In theory you could comfortably use a very small bore pipe, you are only looking at a minute flow, so friction losses will be just about nonexistent. BUT the danger I perceive would be the pipe becoming blocked. Something like a brake pipe could quite well end up with a solidified drip of glycerol blocking the end, or crud simply entering the pipe and getting stuck. What ever way you look at it the head inside the pipe will be the same if the pipe is 3mm or 300mm diameter.
Could you weld a vertical socket to the lid? Save messing up the nice paint job on the tank. The lid could still be removable as once above the fill level, you can use small bore plastic hose to connect to the pressure switch.
With regards to in-processor bubbling, I don't want to raise a scare, I'm just trying to err on the side of caution. The statement comes from the time I was working on Inert Gas systems in the marine industry. In the late 60's early 70's several oil tanker fitted with these systems suffered catastrophic loss and the only explanation anyone could come up with was gas being supplied to the cargo tanks at too greater velocity, causing static. After this design parameters were changed to limit the velocity of gas in the entire system, but I can remember what the limit was.
I've also had static shocks when using a Henry to suck up brick dust and small, general building debris. however, both these instances are very different to what we are doing in the processor. The Henry scenario is a plastic pipe with debris and the IG system was handling many thousands of cubic meters in pipe work up to 30 inches diameter.
I've used the idea for many months with no ill effect, other than the twin PD cant cope with the throughput and it's very easy to emit Methanol fumes from the vent. I can imagine people not fully understanding what they are doing, stuffing a full flow air supply into the processor with possible static dangers, emitting vast amounts of fumes with neighbours complaining to the Authorities and reflecting on all home brewers.
GL's design is beautiful in it's simplicity and safety and I don't really want to promote anything that is a retrograde step in those respects.
Keith and I have been looking at coalescing filters (bet Keith is spending all his time on the new processor and not coalescing filters!) but I've only got as far as putting a sintered exhaust silencer on the vent and over supplying with air. This worked to a degree, roughly doubling the liquid condensate from the vent, but fumes were still snifable in the vicinity.
As a side note, I've made a rig to try the idea on wet bio, but my feeling is that coalescing filter are only good for free water and won't be effective on mixtures or emulsions ... still only one way to find out. I'll post the results once I've run the test.
Keith, I've found a good source of fine aluminium mesh. If you are taking out any kitchens, have a look at the filter in the cooker hood. The one I took apart comprised several layers of fine Al mesh sandwiched between two courser layers.
This is getting rather lengthy, sorry, but back to the in processor bubbling ... if you are going to try it, keep the pipe work large and the air flow low. I did experiment with my aquarium pump when I first tried the idea, but it's really weedy and appeared to make no difference at all. The compressor I'm using is a small diaphragm jobbie which can just be seen, bottom right, in this photo http://www.biopowered.co.uk/wiki/File:Simple_fat_melting_tank.jpg Unfortunately there's no rating plate on it but as a workshop compressor it would be a complete waste of time, the flow is so low.
Currently I'm using a sintered brass exhaust silencer to introduce the air, but I'm not convinced that it's the most effective method. At full tilt (adjusted on the needle valve) and when drying oil, you can hear a "gluging" sound within the processor which I believe to be the bubbles joining together and rising to the surface as series of large bubbles. I think a sparge pipe may be more effective, but I haven't got round to trying it yet. As you two are building it would be quite easy to try a sparge pipe with many widely spaced small holes so that the bubbles don't have a chance to combine.
Finally I think it would be a advisable to arrange things so the bubble stream is nowhere near the heating element. If the element was exposed to a constant bubble stream I think it might cause it to over heat.
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That looks like a compressor for those small art air-brushes. Unfortunately I don't have one of those (yet) but certainly the aquarium bubbler I've got is quite meaty, so we'll see.
It might turn out to be an unnecessary addition what with the pressurised heater spray arrangement that I'm fitting, but I'll add the nipple to the top of the processor just in case (better to have too many ports than too few!). I was planning on using mild steel nipples and just cutting them in half and grinding so that they would weld in place vertically on the dome of the tank.
I don't think Keith will want to modify the bolt-on cap as the steel is really thick (looks to be about 10mm, it's pretty hefty - that said it might be possible to tap to directly take a nipple, assuming Keith has a tap kit that goes that big!).
As for overwhelming the condenser, have you considered abandoning the plumbers delight and going for 25ft of coiled 12mm in a tank of water?
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Just a quick note on the pressure sensor,my plan was to put it together as i build,passing the bend out through the nipple then soldering on the 15/22mm out side part
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Not just a pretty face then?
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Found my packet of nylon fly screen today so thats going on the coalescer pile which actually does exist! so far it contains various grades of fibreglass matting,fine gauze from a body repair kit,fly screen and a nifty ball tea strainer
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Don't know if it's a "BRTP" dewatering devise, I believe others are doing it.
There you are, I didn't think it was an original idea! This from infopop ...
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HDJ80
Member
Posted August 26, 2011 08:17 PM Hide Post
quote:
Originally posted by evangelos:
hello all,
I have been away from this thread so I apologize if this question has been asked already but has anyone tried bubbling inside the reactor to save space?
evan
I have been bubbling inside the processor for 3 years now and works fine for me...
I drain out the glycerol to a second small Hot water Heater and bubble both and using a refridgeration condensor I recover the methanol both from the Bio and Glycerol at the sametime...
HDJ80
Canberra
Location: Canberra | Registered: August 07, 2006
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URL ... http://biodiesel.infopop.cc/eve/forums/a/tpc/f/719605551/m/989100721/p/20
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Back to the original question,what depth does it have to be,im assuming by Tonys comment that it needs to be adjustable to get it in the right place?
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I remember getting this answer from Tony when I fitted mine ... to make it as safe as possible the end of the dip pipe needs to be above the heater by what ever safety margin you are happy with. That way you know for sure there's no pressure in the pipe, before the heater is exposed.
The issue with mine is that, although slightly adjustable, the differential between switch points means that the tank has to be virtually full before it will switch. I was after some thing that would let me play with different fill levels, whilst not exposing the heater. So eventually I'll go for a level switch which I hope will give a diferential of circa an inch or so.
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On mine the tank penetration is pretty much where yours is. From there I ran a 15mm pipe (although for dewatering there's no reason why it can't be smaller, *but see the note below) via an elbow up vertically to a point higher than the maximum fill level and stuck the needle valve on the end. After the valve use small bore plastic.
The little compressor I use has no tank, just a relief valve, so I tend to close the needle valve whilst it's still running to trap air in the pipe, then turn the compressor off. With the piping arrangement above, it shouldn't be a problem if bio/oil runs back up the pipe anyway, it can't go anywhere and will get blown back out next time it's used.
* Just a little hesitant to publicise the idea too widely, because if used for demething I'm sure it'll create a flammable atmosphere within the processor along with the likely hood of escaping fumes. Added to which, small bore pipe work will increase the velocity of the air and just possibly give rise to static, this, coupled with the flammable atmosphere could be rather risky.
Have you got any pics Julian?
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I'm tempted to say ... do you really need a photo of a fitting, a piece of pipe and a valve (as has been said before) ... but I won't!
Yes of course, give me an hour or so and I'll sort out some pickies.
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My system is a bit of a birds nest of pipe work, largely due too many mods., so I've marked up the photo. Yellow arrows show the air path and white the components ... I hope it's fairly self explanatory.
(http://www.palmergroup.co.uk/Bio/Air_bubbler_1.jpg)
This is the little compressor I use, very big and heavy for it's small output.
(http://www.palmergroup.co.uk/Bio/Air_bubbler_2.jpg)
If anything needs further explanation, let me know.
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Ahh,i think im with you now
Is one of these suitable?
http://www.ebay.co.uk/itm/261006206329?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_1438wt_952
and just screwed into the bottom socket from the inside or have you piped it over to be more central?
Any recommendations on the needle valve? and would an airbrush comp be suitable?
Questions so many questions
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That's identical to the one I used, but bigger. I think I soldered mine directly onto a 15mm pipe (being careful the solder didn't run into the sintering) but I may have turned the thread down on the lathe to fit. It does protrude into the tank about 6" .. I don't think bubbles travelling up the processor wall would be as effective. However, like I said before, I have a gut feeling that the sintered silencer isn't the way to go ... I recon a sparge pipe might be better.
I've just had a play in the garage and found a very easy way of putting really tiny holes into 15mm pipe. Many years ago I was given a small quantity of very sharp, very finely tapered, very hard steel pins. They were used for constructing wiring harnesses or looms. I never understood why they couldn't simply use nails, but the guy who gave them to me made electrical control cabinets for a living and said they were the best things to use.
Anyhow using one as a punch puts an incredibly small hole through the wall of 15mm copper. Looking at the depth the pin penetrates and measuring the taper at that point I recon the holes are about 0.6mm. I have vague recollections that they were called layout pins in the trade, but I can't find anything on them with a quick Google. HCII might know what they are called or they could be made from silver steel on a bench grinder and hardened afterwards. If you can wait I can give you one (a pin that is) at Chugs.
I can't find one on ebay, but if you go for a needle valve, this is the sort of thing to look for ... http://www.swagelok.com/search/find_products_home.aspx?show_results=Y&item=42e66d92-14ca-497c-9246-d6922ca2a4c3 but cheaper!
If you are ONLY dewatering oil or bio, you don't really need a needle valve, you can use quite a high volume of air perhaps controlled by a gate valve if needs be. I know you want a condenser to give an indication of when the oil's dry, but during the drying process it's of little consequence if you vent excess moisture to atmosphere, the condenser will still show you when no more water is being driven off.
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And now with my sensible head on ... I could put a pin in the post for you!
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A pin in the post would be ideal,i do have some minute drill bits as well which may be worth me trying,i bought them to make my Babbington nozzle
I will have a look what valves ive got,im sure there must be something suitable knocking about.
The only thing i may have to purchase is a small compressor,i was thinking along the lines of an air brush one but i doubt they are rated for continuous use,i run the Babbington off of a 12V car inflater but they have a tendency to melt after about 15 minutes
Ive found this so far
http://www.ebay.co.uk/itm/Small-compressor-Model-maker-air-brush-/170846059877?pt=UK_Air_Tools_and_Compressors&hash=item27c737fd65#ht_500wt_1202
I would be tempted to buy it anyway,it looks neat!
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What are fridge compressors like?,ive never even looked at one,could they be used?
Julian could you get this one for me?i will pay you back at the BBB
http://www.ebay.co.uk/itm/Needle-Valve-Assy-Bypass-and-Shutoff-Assembly-/160776834340?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item256f0bcd24#ht_616wt_952
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Don't think I kept the address of Tosser Towers, so can you U2U it again please?
To make the hole I supported the tube in a partially open vice, didn't anneal it but that might make the pin last longer.
Ha ... I'd typed this and came back to the thread to find you'd mentioned fridge compressors ... "It might be worth checking if it's a refrigeration compressor, I heard once they're de-gassed they loose their lubrication some how. Don't know how true that is but might be worth asking."
Domestic units are an "all in one" design, commercial units often have a separate motor.
But if you are ONLY dewatering and have a nearby air supply, which I think you said you had, why not fit a decent regulator with gauge and needle valve. You know and understand what you are doing, so with those two bits of kit you can safely control the air supply.
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Well one phone call and a fridge compressor was on the doorstep when i got home,so i will have a play just to see
Taking a step back before i fit the BRTP Exp atmosphere device i had a good look at the dewatering in action tonight.
With the old set up with vertical sides and lid off the steam just blew away,what i noticed today was steam exiting but the conical sides above the oil level were covered with condensation,it looks like my dewatering of the oil is fine but its not leaving the processor, whether this condensation will run back and sink to be removed when draining remains to be seen,any ideas on how i can cure this condensation?
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what if you used a venturi to circulate the air instead of it being stagnant in the head space?
like with the condenser idea...
whats the fridge compressor for?
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A pin in the post would be ideal,i do have some minute drill bits as well which may be worth me trying,i bought them to make my Babbington nozzle
I will have a look what valves ive got,im sure there must be something suitable knocking about.
The only thing i may have to purchase is a small compressor,i was thinking along the lines of an air brush one but i doubt they are rated for continuous use,i run the Babbington off of a 12V car inflater but they have a tendency to melt after about 15 minutes
Ive found this so far
http://www.ebay.co.uk/itm/Small-compressor-Model-maker-air-brush-/170846059877?pt=UK_Air_Tools_and_Compressors&hash=item27c737fd65#ht_500wt_1202
I would be tempted to buy it anyway,it looks neat!
looks kool
http://www.ebay.co.uk/itm/vintage-compressor-museum-show-piece-/170846056241?pt=UK_Air_Tools_and_Compressors&hash=item27c737ef31
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what if you used a venturi to circulate the air instead of it being stagnant in the head space?
like with the condenser idea...
whats the fridge compressor for?
The bolt down inspection hatch is off so it shouldnt be stagnant or is it?
The fridge compressor is to pump air into the bottom through a sparge pipe to speed up dewatering then i will add a condenser so that i know the oil is dewatered
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A pin in the post would be ideal,i do have some minute drill bits as well which may be worth me trying,i bought them to make my Babbington nozzle
I will have a look what valves ive got,im sure there must be something suitable knocking about.
The only thing i may have to purchase is a small compressor,i was thinking along the lines of an air brush one but i doubt they are rated for continuous use,i run the Babbington off of a 12V car inflater but they have a tendency to melt after about 15 minutes
Ive found this so far
http://www.ebay.co.uk/itm/Small-compressor-Model-maker-air-brush-/170846059877?pt=UK_Air_Tools_and_Compressors&hash=item27c737fd65#ht_500wt_1202
I would be tempted to buy it anyway,it looks neat!
looks kool
http://www.ebay.co.uk/itm/vintage-compressor-museum-show-piece-/170846056241?pt=UK_Air_Tools_and_Compressors&hash=item27c737ef31
Ha same guy :)
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Nice looking compressor, I'll keep an eye out for any more he lists.
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Pin received,many thanks
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what if you used a venturi to circulate the air instead of it being stagnant in the head space?
like with the condenser idea...
whats the fridge compressor for?
The bolt down inspection hatch is off so it shouldnt be stagnant or is it?
The fridge compressor is to pump air into the bottom through a sparge pipe to speed up dewatering then i will add a condenser so that i know the oil is dewatered
hmmm this thread has got me thinking, if you look at paint spraying they have an inline water separater / catcher to get the moisture out while pumping air through, wouldnt you get this water/moisture going in the reactor via this fridge compressor which would be detrementle to the cause?
although same with a cindenser/venturi idea but maybe not as much as a compressor?
just a thought chappers....
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Nice looking compressor, I'll keep an eye out for any more he lists.
I wont be bidding,feel free Tony
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what if you used a venturi to circulate the air instead of it being stagnant in the head space?
like with the condenser idea...
whats the fridge compressor for?
The bolt down inspection hatch is off so it shouldnt be stagnant or is it?
The fridge compressor is to pump air into the bottom through a sparge pipe to speed up dewatering then i will add a condenser so that i know the oil is dewatered
hmmm this thread has got me thinking, if you look at paint spraying they have an inline water separater / catcher to get the moisture out while pumping air through, wouldnt you get this water/moisture going in the reactor via this fridge compressor which would be detrementle to the cause?
although same with a cindenser/venturi idea but maybe not as much as a compressor?
just a thought chappers....
Have a look at Julians pic on page 2,it includes a water trap
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koolio :)
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Just been reading through this thread and to answer Julian F's problem about setting the switch,
if you use a large bore pipe inside the reactor it displaces more air,
this will activate the switch with a much finer tolerance.
I use 15mm and I estamate that it needs around 12" to 15" to be submurged before it will trip the switch.
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Bugger,just used 15 on mine,not too much of a problem to change tho,might just change whats inside the tank
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I've got a couple of 28/15 reducers so if I get another two of those thanks I'll use 28mm in the tank and 15mm at the exit,
that should give me quite a fine level tolerance.
Spoke to the driver that brings the tanks in yesterday, he said he can get me some when ever I wont them,
so as soon as the new shed is up I'll give him a shout.
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I've got 15mm in tank and the switch has two trips, one that trips at 2.5" submersion, one at 5". So it must depend on which pressure switch you use.
I've got some hotpoint ones for the new reactor (very common metalflex) so I'll test those with 15mm in a water filled coke bottle before fitting.
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Not sure what make mine is but it has two trips
(http://i316.photobucket.com/albums/mm323/KRH01/Switch.jpg)
(http://i316.photobucket.com/albums/mm323/KRH01/Switch003.jpg)
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That looks the same as mine Keith.
But mine was "adjusted" before I got it so it may need more or less pressure to switch it than yours does.
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It'd be good to get everyone's experience on trigger depth and put it on the wiki page.
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Had a rummage about and found this old switch,any ideas on how it should be fitted/wired?
(http://i316.photobucket.com/albums/mm323/KRH01/bd0d17c2.jpg)
(http://i316.photobucket.com/albums/mm323/KRH01/daf7f13a.jpg)
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That's an interesting bit of kit - where on earth did you find that?
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I had two,one came on a pump the other off an old compressor,trouble is i cant remember how to plumb it in,with just the two terminals i guess it may be a case of just breaking the live