Am 16.08.2016 um 09:58 schrieb scott:

> You are given a bucket of water (fixed to the ground) and an open-ended
> flexible pipe leading off into a "black box". All you know about the
> black box is that it may allow some flow into it, at a variable,
> unpredictable rate.

I presume the "black box" is at the same level as the bucket?

> Design a system to take the water from the bucket, and supply it into
> the pipe at a constant pressure (not a ridiculous pressure, just
> something like the pressure you would have in your water pipes at home,
> maybe 3 bar?).
> 
> Maybe I just hang about too many engineers, but to me even a
> non-engineer would be able to have at least a stab at some ideas for
> solving it.

My first stab would be to re-invent the water tower - though I guess
you're after a more compact device. (Which is a pity, because it's the
solution that places the lowest demands on the pumps.)

My next stab would be to use a gear pump, and offload the tricky part to
some other engineer whom I'd contract to build a constant-torque motor -
though I guess you'd consider that cheating.

Yet another stab: Use a pump that can provide the projected peak flow at
a pressure of 3 bar, and connect a safety valve that opens at 3 bar.
Obviously this wastes a lot of water, but we can fix that by feeding the
spilled water back into the bucket.

Post a reply to this message