Fluid flow question

[Icydash]

I recently bought this Y splitter:
Dawn Industries PVC Funny Pipe Wye (1" x 1" x 1/2")(SY010)s

https://a.co/d/2LqknbG

I attached the input side of a pump to one of the big ends of the splitter, and then turned on the pump. I assumed some water would shoot out the little side path. That was the goal anyway - to split off some of the input water to the pump down the side path. But no water came out the side path. Can anyone help me understand why. And is there anything I can do to get some of the input water to go through the little side path?

This is the pump:

PULACO 400GPH Submersible Water Pump with 5 ft Tubing, 25W durable fountain water pump for Pond Fountain, Aquariums Fish Tank, Statuary, Hydroponics

https://a.co/d/8ZKZKUN

I hot-glued the splitter to the front of it, by the intake. The rest of the pump worked fine when I turned it on, just nothing came out the side path.

 

[3DDave]

Intake is where water goes in. No water should come out.

If you added the splitter to the outlet then little water will come out the side because water has momentum and that vector s not pointing sideways.

You need to eliminate the majority of the momentum with sufficient back pressure to add a sideways component to the flow.

 

[SWComposites]

A photo would really help show what you are doing.
What is the orientation of the Wye relative to the flow?
Why do you want to split off the "input" side flow? why not split off water on the exit side of the pump?

 

[Icydash]

The wye is about 30% offset relative to the flow direction. I just glued the big side of that splitter piece to the front end of the pump, so the setup isn't all that complex. The pump pulls the water through the main body of the splitter, given the suction, so I hoped maybe some of the water would also "peel off" and flow through the Wye. The splitter is on the inlet/frontend rather than the backend because in the real commercial application I won't have access to the backend of the pump.

 

[3DDave]

Whatever pressure is pushing water into the suction side of the pump will be pushing it into the wye.

Maybe a cyclonic separator could have a small scoop to capture the momentum of the fluid flow and cause some to leak out, but it won't be much flow.

 

[waross]

Some confusion between input and discharge.
If the wye is on the input side, the body of the wye will be under negative pressure and watter will tend to go into the branch instead of out of it.
If the wye is connected to the discharge of the pump, you may not have enough back pressure.
Try installing a 1" x 3/4" reducing bushing into the outlet of the wye.
If that is not enough, add a 3/" x 1/2" reducing bushing into that.
Still not enough side flow?
Install a plug and drill a 1/4" hole in it. Increase the size of the hole in steps until you get the side flow that you desire.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Icydash]

Thanks everyone. Let me see if I can draw up a picture to post tomorrow. It sounds like the problem is that, because the splitter is on the input side, the wye is sucking water in (along with the rest of the splitter), rather than pushing it out. Which would make sense.

 

[Icydash]

I've now made a picture, see below.

I was hoping that the fluid would flow as shown by the blue arrows, with at least part of the main flow into the pump breaking off and going through the Wye. But that doesn't seem to be happening.

 

[Latexman]

Raise the pump with something and turn the Wye down. If the suction is flooded and there is enough head, and resistance in eye is small, there will be flow out the wye.

Good Luck,
Latexman

 

[Snickster]

Flow is from region of high to lower pressure. Flow on y-branch will be into pipe.

 

[Icydash]

Is there a way for me to create lower pressure at the y-pipe to siphon off some of the flow? I'd like the water to flow into a secondary reservoir.

 

[IRstuff]

I was hoping that the fluid would flow as shown by the blue arrows, with at least part of the main flow into the pump breaking off and going through the Wye. But that doesn't seem to be happening/

That's not the way inlets work; your pump is sucking water in, so regardless of which direction you place the wye, it will be an inlet and not an outlet. You are better off diverting flow from the the outlet of the pump

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[3DDave]

If you put in a shuttle valve - wait for the main line to build momentum and then shunt that momentum to the second stream in a pulsating flow. This will stop the flow to the pump momentarily, but if another valve opened a second inlet path to the pump it would decrease cavitation; it will stop the normal output from the pump while diverting.

Buying a second pump is the better approach; no complicated flow control required.

 

[Icydash]

Thanks everyone.

I was hoping to avoid having to do anything on the backend, since in my real application I may not get access to the backend. But it sounds like there's really no other option. If there's no other option I guess I'll give it a shot... Is it as simple as just buying one of these and hooking it into the line?

https://www.amazon.com/dp/B08FTMS11Y?psc=1&smid=A26DOZ8RCHN727&ref_=chk_typ_imgToDp

 

[3DDave]

We have been given no goal for this effort - while it is straightforward to determine what cannot work, how do you suppose we can tell if a particular solution will work for your problem?

 

[Icydash]

I'm just trying to divert some of the water running into a pump to a separate tube. I've listed the pump make/model and other component parts. Let me know what other info you need.

The goal is to build an aftermarket attachment for a fountain. The pump itself is embedded in the fountain in a way where you can't really access the backend. I also don't want to make that average person start messing with the backend of the pump to install the device. I'd rather the device be a simple attachment to the frontend for ease of installation.

 

[3DDave]

You have access to the tank. Put another hose into the tank. Make no attachment to the front end.

 

[waross]

Buy another pump and hose.

Yiou may be able to fashion a ram pump that works on the pump inlet, BUT.
A ram pump operates by interrupting and abruptly stopping flowing water.
Every time the ram valve slams shut, the inertia of the flowing water pushes a spurt of water out of the secondary discharge.
Unfortunately, the flow through the pump abruptly stops each time the ram valve closes.
Not a nice thing to do to the pump.
Also the flow of water to the fountain will be interrupted.
You can fix that by putting an accumulator on the pump discharge, but it won't help the pump itself.
Oh. Wait. You don't have access to the pump discharge to install a device.
Just bite the bullet and buy another pump.
I won't say that there is nothing that you can do on the discharge side, just that it just isn't worth it.
And by the way, the adjustment of the valve spring on a ram pump maybe somewhat critical.
If anything disturbs or changes the flow velocity, your ram valve will probably need adjustment.
A ram pump is not a "Plug and Play" device. It needs tender nurturing.
The constant clicking of the valve may be annoying.
Just buy the second pump.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Icydash]

Thanks! Unfortunately my task is to make this work without a second pump, which would double the maintenance and increase costs too much. We were hoping for a cheap and easy solution. But it doesn't look like that's possible.