Water level for steam gen.

[Tammuz]

I use this and a water solenoid to maintain my level. I never could get a float to work right.If you get one make sure you match the threads


$21.25 | Liquid Level Electrode Probe G1 Inch Thread High Temperature Resistance Liquid Indicator Water Level 3-Pole Level
https://a.aliexpress.com/_mqSqgPt
https://a.aliexpress.com/_mqSXDcX for the board in your meter panel
.

[Bolverk]

The trick to making one of the analog floats work is 1 minimal back pressure on the steam side and 2 maintaining at least 10 psi on the water feed. That said I've been looking at this 3 probe solution if/when my float fails.

[Yummyrum]

Tammuz
They show it as having all the rods the same length .

Did you need to cut them to get that controller to work ?

Are they solid rods?

[SW_Shiner]

Looks interesting.

Tammuz
They show it as having all the rods the same length .

Did you need to cut them to get that controller to work ?

Are they solid rods?

A line from the description.
* Please note: This probe is made of stainless steel, if it is used longer, it can be cut to a suitable length and it will work as usual.

[Yummyrum]

Looks interesting.

Tammuz
They show it as having all the rods the same length .

Did you need to cut them to get that controller to work ?

Are they solid rods?

A line from the description.
* Please note: This probe is made of stainless steel, if it is used longer, it can be cut to a suitable length and it will work as usual.

Cheers SW , missed that

[Tammuz]

Now I just need to figure out the size of drip/flow emitters so I don't stop the boiling.

[Bolverk]

Now I just need to figure out the size of drip/flow emitters so I don't stop the boiling.

Put a needle valve on the water inlet so you can try to match the steam boil off rate.

[Yummyrum]

Now I just need to figure out the size of drip/flow emitters so I don't stop the boiling.

I was wondering about this . With a three wire sensor , yih have to have an upper and lower level. The valve turns on when the lower level is reached . Then it slowly fills until the upper level reached .

The two levels would need to be fairly close or I’m imagining that there will be a period if fast boil until the lower level is reached again .Then a period of lower boil rate while the water slowly fills .

Just wondering if the hysteresis is going to be worse than a simple on/off float switch and solenoid .

[Tammuz]

Now I just need to figure out the size of drip/flow emitters so I don't stop the boiling.

I was wondering about this . With a three wire sensor , yih have to have an upper and lower level. The valve turns on when the lower level is reached . Then it slowly fills until the upper level reached .

The two levels would need to be fairly close or I’m imagining that there will be a period if fast boil until the lower level is reached again .Then a period of lower boil rate while the water slowly fills .

Just wondering if the hysteresis is going to be worse than a simple on/off float switch and solenoid .

I have a 4 pin but that doesn't matter.
What's the difference besides one costs more, more work to install,and has moving parts.
Once it drops below the high mark, water slowly enters .(float levels usually are lower and quicker water entry.) If for some reason there's not enough water the lower pin will kill the element . NO moving parts and is easy to clean. You could put a 20k element in there and the massive water movement would have no effect.

[Yummyrum]

I thought you were using the Aliexpress three level controller you linked to in OP .
It has several modes but all start and stop when either high or low sensor is reached .It’s to stop the pumps constantly switching on/off .

[Tammuz]

I use gravity feed water so no pump is needed. I'm waiting to go to the big city to pick up 3 emitters. One of them will work. The first one I bought could keep up with a stripping run. I thought of going much bigger a use a valve to throttle in down,but I prefer to streamline with the right flow. The others will get used elsewhere.

[Tammuz]

I thought you were using the Aliexpress three level controller you linked to in OP .
It has several modes but all start and stop when either high or low sensor is reached .It’s to stop the pumps constantly switching on/off .


IMG_2180.jpeg

yummy This one I bought ,which is more then needed. But I have some other ideas for the extra probe.


$22.00 | 1 Inch 4-pole Stainless Steel 304 Electrode Water Level Probe Probe Probe Rod Sensor
https://a.aliexpress.com/_mMH8uZz

[bluc]

Does your controller open a solenoid rather then turn on a pump? I have seen it mentioned that at least 10psi on water inlet for steam gen is recommended which in my mind makes sense.
If fed from a barrel maybe a pressure pump like used in caravan water systems might be a good thing?
Bolverk do you think these electronic level sensors would be better? Eliminate the issue you had around steam pressure and water level?

[bluc]

Still confused as to how these work do you cut one probe short for low level reading?

[NormandieStill]

I have a Blichmann Autosparge as a part of my beer brewing setup (Basically a classic toilet or header tank float switch but in stainless steel). It has noticeable analogue behaviour in that when you are far from the limit water comes in very fast and the rate slows as you approach the limit so you rapidly match the flow rate out.

Any purely digital system will struggle to match that level of control. I don't have a steam generator project on the cards (yet) so I don't know how much of an issue that is.

[Yummyrum]

Still confused as to how these work do you cut one probe short for low level reading?

There are a lot of ways to use them bluc and how you use them will be determined by the sensor circuit you use and what exactly you want it to do . Short answer , yes , you need to cut to length .

Also how many probes you use will vary depending on what yiu want and how you do it .

Remember that these probes use conductivity of the liquid as the means of operation .
The simplest option uses just one probe and the metal of the boiler as the other return conductor . When the liquid reaches the probe , there is a circuit from the boiler to the probe . The sensor circuit will detect this small current and switch on a solenoid or a pump or an alarm or what ever you want . Or….. it might turn it off .

So say you have a single probe in a steam boiler , as the water boils and level drops below the probe , the circuit through the water to the probe is broken and the detector circuit will do its thing , turn on the pump or solenoid which will fill the boiler until the water touches the probe again , stopping the water flow . A fill Solenoid clicking on/off every few seconds should maintain a constant level withe minimal quenching.

So why do these probes have 2 , 3 or 4 wires ?
Well there are a couple of reasons .
The first is that sometimes , the boiler or vessel is not made of metal , so an extra probe is used to create the circuit through the liquid . This probe needs to be longer than the level sensor probe .It might reach down to the bottom . ( But it only needs ti be a bit longer than the level sensor probe to work)

Another reason why an extra return probe is that in an industrial environment where there are lots of high power circuits being used , it is better electrical design to have the sensor circuits using their own conductors . This ensures the sensor circuits are not subject to interference from the high power circuits .Now we have discussed needing two probes .

Why have three probes ?
Say you were draining your waste into a bucket and wanted to have a pump to pump it down the drain .
If you just had a two probe system , yiu would have it setup so that the return probe went to the bottom and the overflow probe was near the top . As the liquid reached the top probe , the pump would start .
But then it would run for a second or two until the liquid dropped . You would have a problem because the pump keeps starting and stopping . Very annoying and very quickly wears out the pump with all the stopping and starting .
So this is where the third probe is used …. and a hysteresis circuit .There would be the overflow probe at the top , but also a low level probe near the bottom of the tank . As well as the return probe which goes all the way to the bottom and is used as a common to both the upper and lower probes.

Now , when the liquid level reaches the overflow probe , the pump starts , but it keeps running until the level reaches the low level probe . The pump stays off until the level rises back up to the overflow probe at which time it all repeats . This is the operation of the Aliexpress level circuit linked to above . It is not suitable as a level control in a steam boiler because the rise and fall times are going to create an inrush of cold water for a long period that will quench the boil .


There is however another use of a three probe setup in a steam boiler . That is using the simple two probe setup to regulate the water level ( via a click click fill Solenoid) , but using the third probe lower down just above the element to switch off the element if for some reason the level gets dangerously close to exposing the element . It can also be used to not let the element turn on until the level in the boiler has initially risen to cover it .

As for the fourth probe , well you could use it to indicate that the level in the boiler was too high . Say the fill solenoid jammed on , an alarm might sound .

Or you could cut it off and not worry about it .

[Bolverk]

Bolverk do you think these electronic level sensors would be better? Eliminate the issue you had around steam pressure and water level?

I don't know that I'd say "better", just a different way of achieving the same goal. Now that I figured out the pressure issues my float has been dummy proof. I will say If my analog float fails I will try these sensors.

On a separate note, My drain in my basement is up at about 5ft so I am working on an effluent waste setup that uses these sensors to pump the waste out instead of needing to bail buckets.

[bluc]

Anyone try one of these working temp 0-100⁰c Pressure rated to 1mpa look interesting.



https://www.ebay.com.au/itm/38677704662 ... media=COPY

[Yummyrum]

Looks good bluc . Was worried about 0-100°C as it would be sitting in close to boiling water but the internal plastic is Nylon which is happy up to 150° and can withstand 200°C for short periods .
So assuming it is most likely going to be showered in cool water , it should last just fine .

The mechanism looks like the float and needle in a petrol fuel bowl .
I’d imagine as long as there was sufficient baffles between it and the main boiler , it shouldn’t bounce around too much and be fairly stable . I’d be keen to try one . Just need to increase size of my sight glass . @48mm dia , it would almost be too large in a 2” .

[Tammuz]

Yummy I like the way you take the time to explain things. I just look at it as 0's and 1's. Either on or off or off and on. A gravity feed pressure compensating valve that matches your evap rate is KISS. No moving parts,pumps .