a rather tricky solution reqired..

ELZ4742 · 24 Feb 2007

right guys, time to put your thinking caps on

i need to be able to control the level of water in a material seperation unit so in theoroy a float switch would be ideal, however, the way the materials seperate is that one part sinks to the bottom and the other part floats. the problem im facing is that a normal float switch either sits under or on top of the floating materiel rendering the switch useless. ive tried a mechanical (ballcock type) switch but the material blocks the moving parrts causing it to stick open....

any ideas?

bernardgreen · 24 Feb 2007

ELZ4742 said:
i need to be able to control the level of water in a material seperation unit so in theoroy a float switch would be ideal,
any ideas?

Use an external tank with simple float switch. Connected via a pipe to the bottom of the settling tank. In theory the floating material will not get through the connecting pipe.

Same principle but use a glass ( or other non metal tube ) as a sight glass and a floating magnet with sensor. You will need to prevent the magnet floating above the sensor.

Connect a pressure sensor to the base of the tank and have a setpoint switch for the pressure at the required depth of fill.

TicklyT · 24 Feb 2007

Take a tapping from halfway up the tank to avoid most of both the floaters and sinkers. Link to a pressure switch as used in a washing machine?

ELZ4742 · 24 Feb 2007

cheers bernard! great ideas, ill let you know how i get on.

Spark123 · 24 Feb 2007

Ultrasonic level detector connected to a (PID) controller operatating the input valve?
The problem you may find with a single switch operating the valve is when the liquid level drops the valve will open, level rises, valve shuts constantly it will take its toll on the valve, may even cause a hammer effect.
One problem with using pressure a pressure switch is the SG of the liquid will need to remain constant.

securespark · 24 Feb 2007

S*d all of that.

Keep it sweet & simple & fit a paracycling valve chamber in the tank, filtered of course, linked to a wireless microwave tilt sump switch with variable valve timing (a la Toyota) to avoid the aforementioned hammer effect.

Finish off the job by linking the whole kit & kaboodle to a remote semi-nuclear passive controller, Type A300S.

Easy-peasy!!

Spark123 · 24 Feb 2007

Still trying to figure out what ELZ4247 is building in his shed

tim west · 24 Feb 2007

Are the materials conductive in any way? you could make a level switch (the electrode type) and tune the circuit to identify between the water and the material by resistance measurement or otherwise their specific gravity may be different and you could devise a circuit to identify this?

Chris.J · 25 Feb 2007

You could float something on the surface, with a thin metal plate on its top. Connect one wire to this. Dangle another wire from above, with a metal ball to keep it taut, when the two meet you have your contact.

bernardgreen · 25 Feb 2007

ELZ4742 said:
i need to be able to control the level of water in a material seperation unit

Is the water level topped up by the addition of water or can be it be topped up that way ?

If so just use a ball cock in a separate tank with a connecting pipe. Set the ball cock to shut off at the level required in the main tank. The advantage here is the flow in the connecting pipe is always toward the tank with solids so these solids are kept out of the connecting pipe and float chamber.

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

a rather tricky solution reqired..

Similar threads