So science/math was never my strong suit. I get the basics of how if you occlude the opening of a flow of liquid, the pressure increases (like putting your thumb over the opening on a garden hose to make it shoot further). Looking at making a gunge tank with at least 3 outlets in the tank (one over top and at least one on each side beside the victim). The pump I am using has a 3/4 inch outlet (actual hosing is about 5/8 inch/15.875mm inside diameter). The pump does not have enough pressure/flow with that size tubing. My tentative plans was to try and split the 5/8" hose to three 1/4 inch/6.35mm PVC hoses plumbed into the tank. Here is where my lack of knowledge comes into play: Since the combined diameter of those 3 hoses is more than the original, am I going to get even lower pressure out of them than the big hose?

And another question. When it comes to reducing size of the tube to increase the pressure/flow, does it make a difference where the reduction occurs? (Closer to the pump or closer to the tank outlets?)

This is the pump I have: https://www.harborfreight.com/12v-dc-transfer-pump-290-gph-63324.html

And this is the tubing I was looking at: https://www.lowes.com/pd/EZ-FLO-1-4-in-Inner-Diameter-x-20-ft-PVC-Clear-Vinyl-Tubing/1000180543

Thanks for any input

-JD

Hi JD. The main flaw, before we even look into pressure calculations, is that this type of pump at this price will not work with viscous liquids which will demand device with a lot more muscle designed to propel them. You might be better off with one designed for draining oil sumps or that can handle dredging more solid matter but you're into much higher budgets.

My recent budget beating experiments with gunge propulsion have involved small vented tanks and air compressors. I am fairly savvy on mechanical and plumbing matters, however, and already own most of this equipment.

Rich

Thanks for the reply Rich! Was hoping to work with what we already have since money is tight. Also, electricity is not readily available where the tank will be (unless we run a really long extension cord). We had done a test with the pump we have last year. The flow was not great (like an average water tap) with the garden hose, but I could shoot the gunge pretty far occluding the opening with my thumb: https://m.youtube.com/watch?v=803c1Rl48u4

Ideally would like to have a set up with a pump that has a pickup that could be moved to the tank after the initial gunging and suck up the gunge in the bottom for a continuous loop. Don't really want to spend more than $100 on this project so may just abandon it if it is not feasible in that budget. Thanks again for lending your insight to this project

-JD

Nice, I like this idea.


The pressure will always be highest at the outlet of a pump. The smaller diameter can increase the speed of the fluid flying out of the end somewhat, but if the pump isn't powerful enough you can't increase the pressure beyond what the pump provides by narrowing the diameter.

In fact, you'll get less flow from the pump because you are making the pump work harder to force the fluid through the narrower tubing.


No. remember that the cross sectional area of the pipe or tube is PI*(radius)^2
because the radius is getting squared, you need to square your numbers to get the ratio

If I want to get the cross sectional area ratio of 3 1/4 tubes to one 5/8 tube I can do

[3* (1/4)^2 ] / (5/8)^2 = 0.48. This means your three tubes have about half the cross sectional area of your 5/8 tube


Yes. narrower tubes are more difficult to push fluid through due to friction. You want the reduction to happen right at the end to increase the velocity. If you have a lot of narrow tubing, you'll get more pressure drop in the system before the outlet.


This pump isn't suited to your application. It's for clear water only. Running slime / gunge or any fluid other than clear water will probably damage the pump eventually.

I'm working on a similar idea, and the first pump I used was this,
https://www.amazon.com/AMT-3201-96-General-Aluminum-Discharge/dp/B008384QPQ/

but it needed a bit more power so i went to this
https://amtpumps.com/site/product/1-1-14-cast-iron-centrifugal/
https://www.mcmaster.com/99435K51/

I had also initially way underestimated the size and power pump i'd need for what i was visually picturing, and I haven't tested everything yet, but moving serious amounts of gunge quickly needs a lot of power.



That's going to make things very challenging.


Nice test, but I don't think you're going to get much more out of that pump.


You'll need a self priming pump to do that. I'm also trying to do the same thing and it been a pain.


I would probably abandon the idea at this point. I don't think I could hit what you want for $1000. Which is a huge shame because I wish it could happen for you.

Scroggle: Didn't want to make this post huge by quoting your entire reply, but thank you for taking the time to make such an in depth response! Sounds like my idea is a fool's errand, unfortunately. Definitely don't have money to spare for a better pump at this time. I may still try modifying the water totes into an enclosure since I already have them. Thanks again for that reply (and especially for the math lesson)

-JD

If you want guidance on pumps, pipe losses pressures/flow etc. drop me a message it's pretty much my day job!