PDA

View Full Version : Pressure tank pump instead of electric pump?



notomo
12-03-2011, 01:32 PM
Just wondering if anyone has tried it, I have not even tried a pressure tank pump yet all thought its on my to do list. My understanding of a pressure tank pump "may have another name for it" Is you have a sealed tank say a 55 gal drum 1 inlet 1 outlet inlet pipe is submerged in water say your fish tank, very first time u use it you also need an air vent on the top say a ball valve so first time u use it you hook a pump up to the inlet pipe and open the air vent also need a ball valve on the outlet so close the ball valve on the outlet. Now fill the tank oh ya I am forgetting a 1 way valve on the inlet to only let water in not out.

So now you pump the tank full of water once water starts coming out of the air vent you can stop pumping, remove the pump now watch to make sure your water level does not drop "this is to check the 1 way valve which should be near the start of your inlet pipe near where you had the pump I believe. So now you have a tank full of water with no air in it a 1 way valve on the inlet not letting the water escape and a ball valve on the outlet also not letting the water escape so now you have your outlet pipe going into your grow bed "above the max water level I believe" open the valve grow bed begins to fill once it gets to top of your Bell Siphon it drains into your fist tank, which also happens to be where you inlet for you pressure tank is.

Now remember there was no air in the pressure tank so whats going to happen as water exits that tank? It should create suctions which will refill the tank at the same time or close to the same time that it is emptying. Thus you no longer need an electric pump.

If I am way off let me know but I believe the theory is sound as long as I did not screw up part of it :) I am sure if you do a search online you can find diagrams etc of how it works, I just have never tested any of it again on my to do list, just wondering if anyone has tried it.

urbanfarmer
12-03-2011, 01:45 PM
Perhaps a picture or drawing would work better in this case because I have no clue what you are trying to say. If you're inventing a perpetual motion machine, well I can tell you it won't work.

commander
12-03-2011, 01:52 PM
I would need to see a diagram, but as you describe it I am pretty sure it would not work.

notomo
12-03-2011, 03:39 PM
Ya I may be explaining it slightly wrong or something, the basic principle is the water exiting the "sealed" barrel creates a Vacuum which then sucks more water into the barrel threw the intake, water can not exit the intake because of the 1 way valve so it has to exit the outlet pipe, and since no or little air is entering the system its a constant suction I thought I saw a youtube video of someone doing it but now i'm having trouble finding it. I will have to ask my buddy who originally told me about it and maybe he can give me the link again.

You may even leave some air in the barrel at the start I can't remember.

commander
12-03-2011, 03:42 PM
I dont think it will work. Once the pressure in side the tank equalizes with the air pressure outside the tank, water flow will stop. There is no energy to draw water in at that time.

Larry Dietz
12-03-2011, 06:16 PM
I would expect that air would be drawn in through the outlet pipe as water exits, since the air could get in easier than the water at the inlet. The outlett pipe letting in air would be the least resistance.

This is just off the top of my head. I have never tried anything like this, but if it worked as you describe, it would be violating some basic laws of physics. You would have perpetual motion.

-Larry

urbanfarmer
12-03-2011, 10:55 PM
To keep moving the water, something has to provide the energy to move it. It won't move by itself forever no matter what.

notomo
12-04-2011, 04:12 AM
I would expect that air would be drawn in through the outlet pipe as water exits, since the air could get in easier than the water at the inlet. The outlett pipe letting in air would be the least resistance.

This is just off the top of my head. I have never tried anything like this, but if it worked as you describe, it would be violating some basic laws of physics. You would have perpetual motion.

-Larry

Ya I was thinking that as well, may be that it was a 1 way valve on both sides so the water can only move the one direction and air could not go back up the outlet. I believe the power would be generated by the vessel emptying as the water leaves it creates suction "tries to pull in the walls of the 55 gal drum like a soap bottle being squezed" once it hits critical mass it begins sucking in water from the inlet, it tries sucking in from the outlet as well but since you have that second 1 way valve it can't.

The more I think about it the more I think it would not work at all, but I still have this nagging thing in my head that I saw a video of a guy doing it and it was like one of those white 55 gal drums so you could see the water in it and when it got down to around half emptied it starting filling back up. But maybe I just imagined it.

My google searches are doing me no good, other than ram pumps are kinda cool.

keith_r
12-04-2011, 07:48 AM
we used to use a pressure "bladder" tank in our well.. you still need to pump the water, and you'd need high pressure to pump.. interesting idea, and there might be a cost savings doing it this way, but i like having a low wattage pump always running

foodchain
12-05-2011, 06:14 AM
This is a perpetual motion machine, the energy used to move the water is gravity and fluid dynamics. But the problem is, there's not enough head pressure to drive the water up hill to the top of the barrel. The water will try to equalize to the level of the fishtank, same way basically the bell syphon works. The only way I know of to make this work, is if the fish tank is sealed across the top too. Very good idea though moving one volume of water to another. I do this through a cascade system. This could be good for off gassing water, and has significant applications with polyculture and minimizing, not eliminating, the need for electric pumps. You still need a main pump to return the water to the top, however one pump pumping straight up will be a smaller, less expensive pump, then either one large one branched out to different tanks, or several small ones. Hope this makes sense.