Im building one Help - im building a prototype cheap

[AL968]

Hi all
Instead of reading about it ive decided to put a flowbench together im using available parts around the house will be spending minimal amount of money this is designed to put together information found here and elsewhere to begin at the beginning this is purely a prototype to test various systems before investing money in motors, manometers ,
please feel free to critisize, question and help.

I will build the flow bench around a restrictor plate design from holes I based purely on the sizes that my hole saw can cut in some aluminium plate i have using home made water manometers-and my trusty leaf blower and some MDF boards left over from a kitchen renovation

my immediate aim is to build all the parts turn it on and if i get up to 5" of water depression i will consider it a success.

if it loads i have a basic sketch uploaded.

my immediate need is if some one can look at my basic plan and tell me if can be workable. and the where to hook up the hoses for the inclined manometer


the only thing missing from the drawing is that there will be
side valves in tube 3 and 8 to close and control flow

[jfholm]

I did basically the same thing to prove the function of the ideas here on this forum. I ended up buying a set of plans from Bruce and I built just the chamber side of the plans. I then plumbed in 2 shop vacs into it and I can pull 10" flowing a SBC head at 263 cfm. I tried to find that thread so you could see it. It is a simpler design than your drawing shows. I know it works great! I would suggest buying the plans and if nothing else just plumb in shop vacs for a very quick and simple flow bench that is super accurate.

John

[49-1183904562]

AL,

Looked your design over and you are missing two critical openings, Intake air Hole while testing Exhaust and Exhaust air hole while testing intake. Your design looks to just breathes in a circular manor.

I think your concept is viable and will be a good preliminary education and is the basic conceptual design of orifice plate type benches. Just remember the accuracy of the data in a bench are based on many things but the two most critical are the Orifice design and the monometer design and setup. So the more careful and precise you build these components the more accurate the data will be.

JMO

Rick

[AL968]

Thanks for the feedback John buying the plans is part of the plan
But at this stage I would cosider it cheating. Thanks for the link.

Hi JMO this is where I learn,

My thinking was
Intake air Hole while testing Exhaust is
orifice plate number 7
in my crude drawing.

And Exhaust air hole while testing intake
being number 4 orifice plate.

My drawing should explain. what I thought would happen.

thanks all

AL

[bruce]

[49-1183904562]

Al;

You are very close on your design, Read what Bruce has to say about the air path. You want the air to move like this on intake "Test part >> Orifice >>> Vacuum Source >>> atmosphere. On Exhaust it will be the reverse.

Your design is similar to a SF 1XX series bench and as Bruce states is affected by the air temp increase at the motors.

Rick



Edited By 1960FL on 1242663202

[AL968]

Thank you Bruce the notes help me to visualize my thoughts I didnt know they had a name, I learn again. I hope its ok.
I havent tried to upload pictures only.

Rick I have used a SF100 in the past and there definitely was a visible movement
in the build in temperature gauges with correction calculations needed for flow figures.
Eliminating that is obviously appealing.

I will do 2 things now

1 A search on temperature relationship to flow and associated mathematics. im sure there will be something on the forum

2 Reconfigure my design incorporating the better airflow schematic.

Anyway it might fit better with my minimal expense Parameter.

Happy Easter

[AL968]

I've fnished buiding the flow bench prototype, as soon as I work out how to put up pictures ill load them.
I have taken the advice given and bipassed the motors and therefore eliminated possible temperature correction problems

I will use sliding plates to control flow and orifice sizing.

The sliding plates and cavity used I havent seen anywhere before, I may have invented something new, Im not sure how well it will work.

I will start it tomorrow, just waiting for silicone to dry properly

My next step is to make manometers and work out where to place them.

[AL968]

Here is a quick snapshot hope it comes up

[AL968]

Almost ready

[AL968]

This is the plenum and test control box this is how im planning to use it please check and tell me if im going the right way
also i need some advice on manometer tube placing both for vertical and inclined.
I know i need to swap vertical manometer between inlet and exhaust as needed im planning on plumbing it in the tubes between the plates in the centre.
For the inclined manometer I need some direction.
thanks.

[AL968]

Hi all
I have a finished, a working flowbench at last , thanks to the notes found on this forum.

I Have achieved my aims 1 a protototype-- 2 cheap--3 run on a 10amp 240v circuit.

It is different than other benches I have seen and I think very simple.

I encountered all the Typical problems How to make manometers, where to place manometer hoses, How to calibrate, what motors to use.Etc
it is easy to service and also upgrade.

I found a way to make Leaf blowers 40% more efficient..

The whole project cost me under $150.00 less hours spent on it.

The performance is better than I expected thanks to the mods to the leaf blower motor

Some quick stats Calibrated at 8" will pull up to 10"-11" depending on how much power the rest of the house is using
Manometer materials are plastic fexible 4mm tubing with coke p e t bottles as wells.
Manometer fluid -water, food colour, dash of dishwashing liquid a few consistencies were tried.
Motors 2 x 1800watt GMC leaf blowers.

I flow tested a cyinder head that was tested on a SF110 and was with in 1-3cfm in the flow curve I calibrated
and measured my orifice plates with the same bench.