Float Switch

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Justin

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Ok guys, who has ideas for a float switch for maintaining a level above the grain bed while sparging with a pump? Anyone found anything suitable in Australia?

I know morebeer have an off the shelf solution (and a nice price tag to go with it ;) ) but I was just curious to see if anyone else has found or had ideas for a float switch to contol my pump while sparging. I have access to some electronic solenoid valves that I can put in line to the sparge manifold that will shut off the pump (march 809, so no worries about restricting flow), or perhaps I'll set up a relay to electronically shut the pump off, guess it depends on the float switch and my final decision.

I haven't built it yet but thinking about how I want to do it all. I think my new system will be like the sabco brew magic in that mash tun and HLT will be on the same level (http://www.kegs.com/brewmagic1.html), boiler below. So I'm thinking that I may or may not need a check valve between tun and pump-to stop back flow/syphoning (because they are on the same level). I'll play with it manually first and see if it is very hard to manually maintain the level just by controlling flow from the pump but I guess eventually I'll automate it.

I'd like to not have 240V hanging around in my mash tun but I'm pretty stumped for ideas. What can others suggest? I'm thinking that I may be able to fabricate a 12V mechanical type switch that I could perhaps attach to my sparge manifold.

Oh the joys of building, planning, redesigning and then doing it all again.

Thanks in advance.

Justin
 
Justin,
you may not have any success with a solenoid valve in a low pressure application such as you are talking about. Solenoid valves require a good high pressure supply on the upstream side to both open and shut fully.
12V switch to a relay to control your pump sounds like the go. A check valve sounds like a good idea too, but you will have to be careful with anything you select as it will very easily held open by a small part of grain or whatever, and thus do bugger-all.


dreamboat
 
Thanks Dreamboat, I haven't played with solenoids before so I don't know a lot about them, but just taking to a friend he said he had a couple that I could get off him so I had that down as an idea.

As for the check valve, that's a good point, perhaps a small filter placed inline above the sparge manifold would be a good idea. Not quite sure of the check valves available. I've got a tooheys keg coupler here that has a checkvalve in the body of it that I thought I could adapt, it seems to work really well and I thought that it might be ideal for my situation. More playing around will determine whether or not it will work.

Cheers and thanks. Justin
 
Justin.

I've got the morebeer one... It does the trick, but I find the delta a bit small, so pump is switching quite often....

One Idea could be to check out marine supply places and look for a float switch designed to drain bilges. they may also be able to supply a ball type check valve in a small size. I'm still looking for one of these myself... Blackwoods have high temp plastic ball check valve, but there an order-in item so haven't laid my eyes on one yet....

Asher for now
 
A possibility may be some sort of Ultrasonic sensors like here? Haven't used one but would sure like to know if anyone else on the board has played with one and got good results. They retail for about $50 but you do need the PIC controller and Solid State Relay as well so it starts to get pricey. The PIC can do other stuff for you though if you wanted to automate more things so it may be attractive longer term?

One good thing is that the sensor/PIC runs off 5V DC so no fear of mains power in the mash tun.
 
Holy shit. I'd be too afraid that it would be too smart. I'd probably walk away and let the sparge happen and while I'm away the whole system just sits back, has a beer and has a chat and messes around, then when I come back it senses my return and then gets back to sparging (it can sense a 3cm broomstick from 2m's). All the while I'm none the wiser. Nah, bit of over kill I reckon, just toying with the idea atm but reckon I'll do it if I can find a cheap price. I just wish we could buy stuff from grainger or mccarr-master, some nice stuff there for the homebrewer and bloody cheap.

JD
 
have you considered using a three probe system?
One long common, medium sized cutout and a short cut in. They can be a bit tricky to set up getting the vloltages right but after that they are great unless they are measuring pure water.
 
Well I've found these here at www.rsaustralia.com and will buy from them unless I can source locally from either an aquarium shop or hydroponics shop (also the same ones at www.farnell.com).

http://www.rsaustralia.com/cgi-bin/bv/brow...atoid=-84769096

And these ones:

http://www.rsaustralia.com/cgi-bin/bv/brow...atoid=-84766036

Both types look suitable and if you want you can get them to handle up to 130C if you want. So looks like I'll get out of it for less than $30 delivered, sold :D

Automatic sparge float control here I come. I reckon I'll get a small 12V power source so that there isn't major voltage going into my tun the use the output to throw a relay conrolling my pump. I'll wire the pump in so I can set sparge control to auto or switch to manual running. This is fun :D

Thanks for the input guys. Will post details when I get it done.

Cheers, justin

horizontal_float_switch.jpg
 
And vertical ones. These look the go I reckon. Thinking about mounting them in a short length of PVC pipe with an endcap, drill a hole in the end to mount.

Vertical_float_switch.jpg
 
As mentioned before, this type of system has a fairly short deadband of probably just a couple of centimetres. It would be fairly simple to utilise two of these to energise and de-energise your relay, to enable you to set a much much more appropriate deadband.
Alternatively, if you limit the rate of inflow to be just a touch over what will sparge out, then you will not have the system constantly hunting.


Dreamboat
 
You just gave me an idea for a mash tun.

If only I can figure out how to get a burner under the bowl I have a ready made two tier setup.

AutomaticMashtun.jpg
 
Those float switches pictured would be the go.
I used one in a hot water tank of a cleaning machine once, to protect the hp pump from running dry should the machine run out of water.
I had thoughts of using one for sparging then I discoverd batch and the no - sparge methods and I now wouldnt bother fly sparging at all.
Of course, this is a personal choice.

Cheers
 
I've read over that site a number of time and am actually heading off to a secret location today to get an old old corny that I found to maybe oneday make a mini heat exchanger out of if I ever go that way (it's a racetrack type lidded one, but doesn't have the racetrack lid-it's just solid, but instead it has one 2" hole in the top that accepts the old spear).

In regards to the float switch that's pretty much exactly what I would like to do. I started hunting around for cheaper float switches once I saw how cheap the grainger one was. From what I can see the ones at rsaustralia are exactly the same switches and they are only around $20ish, plus $8 postage so that's pretty cheap in my books. Dreamboats hit the nail on the head with the idea of slowing the flow from the pump down to just over what your draining rate to minimise the frequency of switching on and off.

Cheers, Justin
 
sosman said:
You just gave me an idea for a mash tun.

If only I can figure out how to get a burner under the bowl I have a ready made two tier setup.
Looks like a job for an immersion heater - aka in some circles: The Rod of Power
:lol: :lol:
 
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