I have a large shop vac, 2.5" hose, 2.5 horse motor. How would the end
suction power compare with a 40 or 50 foot hose? Would it drop
considerably? I want to use one to harvest pecans, and need the length,
plus, it will drop them in a 55 gal. barrel.
Every yard is different. At some times, I can pull right up, other,
not. I do have hefty extension cords, but even with the cord right
under a tree, a 20 foot tube can be minimal, making it necessary to move
the vacuum frequently. I am working on mechanization, getting barrels
that the vacuum motor head is interchangeable on, a hoist on the truck,
and automatic onsite cleaning and processessing so that I can leave
waste on site. But for these first couple of seasons, I need to just
keep it simple, see how they actually do sell, then decide if I want to
jump in deeper. I work by myself right now, so having a long hose is
nice if I can leave the barrels on the truck, and just drag the hose
over to the tree.
One size does not fit all.
The suction at the end of the hose and the air flow through it will
always be highest when you have the shortest, straightest, smoothest and
largest diameter hose. That's why appliance manufacturers recommend
that the exhaust vents from clothes dryers be made of rigid aluminum or
galvanized steel and be as short as possible with the fewest number of
If you can, it'd be best to lay something like 4 or even 6 inch diameter
12 foot long lengths of ABS or PVC pipe from your truck to the tree, and
then have a 2 1/2 inch outlet at the end of that piping that you can
connect your vacuum hose to. Your vaccuum motor would be at the other
end of that piping, possibly sitting on top of a 4 or 6 inch plastic
elbow. That way, MOST of the route the air flow takes is through much
straighter, smoother and larger diameter tubing, which will provide for
much lower friction losses than an equivalent length of 2 1/2 inch
corrugated plastic hose.
Just as a first approximation, if you take the ratio of the squares of 2
1/2 and 4 inches, you come up with 16/6.25, or about 2 1/2.
That means the speed of the air through a 2 1/2 inch hose will be about
2.5 times as fast as it will be in a 4 inch pipe, and that should
translate to 2.5 times as much friction loss per foot in 2 1/2 inch
tubing as compared to 4 inch pipe. And, that's not even considering the
other factors, such as the smoothness of the ID of the hose or pipe, and
that's a biggie.
So, you might still have enough suction and air flow to gather pecans
with a 40 or 50 foot long 2 1/2 inch diameter corrugated plastic vacuum
cleaner hose, but you'll have way more suction and air flow if you
replace MOST of that 2 1/2 inch hose with straight smooth pipe of larger
diameter. Say, 40 feet of pipe, and 10 feet of hose.
The tight fit of ABS or PVC piping and couplings should allow you to
assemble that piping so that you don't have much in the way of air
leakage into the piping from the outside, and you should be able to
disassemble it yourself as well, possibly with the aid of a rubber
mallet or wooden meat tenderizer.
On Friday, December 20, 2013 12:38:18 AM UTC-5, nestork wrote:
No question that the larger the pipe diameter, the less restriction it has
to airflow. And also no question that the large the diameter the slower
the air will move. A 6" diameter pipe is going to have an air velocity
that's just a small fraction of the air velocity in a normal 2" shopvac pipe.
Have you considered what that reduction in air velocity will do in terms
of being able to *transport* the nuts? At some point, if you make the
pipe large enough, the nuts are just going to lay in the bottom of the
pipe and not have sufficient air velocity to go anywhere. I wouldn't be surprised to see that happen with a 6" pipe.
Before I did anything else, I'd just go get a couple lengths of shop
hose and try it. If it works, it's a simple, easy solution. I would
think some arrangement to keep the pipe sloping mostly downward, from
the point were the tree is being vacuumed back to the vac would
also be beneficial if any problems develop.
2.5 HP. I can't remember how many HP on my shop vac. I know my
bigger one** ??HP, came with a 10 foot hose at least, maybe 12 feet.
Compared to the 1?HP, wich came with about a 6 foot hose. I can go
measure their lengths and find out their HP if you want.
**That I had to buy to use soot bags to clean the furnace. The
smaller one wouldn't accept soot bags.
Is there any way you could test the long hose at home? With the vac
on your truck as you expect to use it. To do comparisons, not
measurements, so you can compare the shorter hose you're using now
with a 40 or 50' hose^^ (YOu wouldn't want the hose lying on itself
I think, requiring the pecans to climb one hill and later another.
Just flat even if it's way spread out seems better to me. ) Would
buying one be too big of an investment if it doesn't work. Or maybe
you could return it if you made no modifications**. You could test
the vacuum by pointing the opening down and having a set of booklets
and books, with similar covers*** and seeing how heavy a book(let)
could be held up by the suction, YOu could rubber band the book
shut where the rubber band would not interfere with the suction.
Maybe instead of booklets and books, a box would be better, flat and
stiff on the top side so the suction doesn't escape*****either open or
openable on one side, so you could put heavier and heavier things
inside to see how much the suction/box could hold, COMPARED TO the
hose you're using now, which you woudl also have to check. .
Even though everything they've said about length and turns and rough
surface decreassing suction is probably true, that doesn't say how
much it is true. Experimenting is likely to tell you that.
And maybe if necessary you can improve your technique so you come at
the pecans from underneath and they falal into the hose.
You know, I'm not sure you want the largest diameter, just to get the
highest suction at the end. Larger diameter means iiuc slower air
speed, and you may need high air speed to get your pecans all the way
to the truck. without their slowing down and stopping in a low spot on
the hose. If you try to suck on a drink through a straw, the drink
will zip up the straw and hit the top of your mouth, but if you have
a bowl big enough to put your face down to the surface of the same
liquid, and you suck only with your wide open mouth, you wont' get
much to drink, I think. You could try using thin straws and thick
straws and comparing.
But this isn't the best comparison because it's a liquid and not
discreet items like pecans. It's just that liquids are the only
thing I have experience with and if one uses a 2 inch diam straw, it's
going to be hard to suck. Your suction may not have the strength to
hold up a column of coca cola 8 or 10 inches high and say 2" in
diameter, but it's easy if the straw is 1/2 or 1/4" in diameter.
That's a better illustration.
Are you the only one picking pecans with a hose? Surely others have
tried this, and might sell equipmeent to do this. Check what size and
lengthy hoses they use. Are there farm machinery stores where you
could talk to a salesman or owner. You could pretend you want to buy
something (and maybe you will want to in a few years) or you could
tell them your just starting out and need advice. Go when they're
not busy which is often two hours before closing. Or search the web
****(even though it will when your at the trees. You don't want it to
escape here because you're just doing comparisons, not measurements.
If it was pliable and the suction escaped, it would be hard to keep
the same amount of suction escpaping for each test.)
***That is, if one cover is glossy, they all should be or at least
enough to do some comparing with should be.
^^. (and maybe a hose that's not smooth inside with one that is, if
you have a choice about inside smoothness, )
**or even if you neatly cut off the last 1/2 inch that you damaged.
I don't generally approve of that, but on a 40' hose, 1/2 inch, even
if it's at both ends, is very very unlikely to hurt the next buyer.
If you can cut it off neatly.
On 12/25/2013 5:41 PM, micky wrote:
Seems to be a lot of faffing around using fluid dynamics
principles that may not be relevant.
How about this?
Take the collection barrel to the tree and use a short hose.
The long hose to the motor does not have to carry the pecans
and can go uphill with no pecan jamming or loss of flow.
Isn't the second sentence contradictory to the first?
Hmmmmmm. Lemmmesee .................
I got this vacuum head that fits on top of a 55 gallon metal barrel, so
that I can have lots of barrels, and only one vacuum head. And leave
the barrel in the truck or trailer. Then change barrels when one gets
filled. So far no need for a wheel that I can see. The 55 gallon head
doesn't fit a 40 gallon barrel. Won't fit the 33 gal barrel either.
But, then, that's old math. Using new math they teach at school these
days, it MIGHT work, but I'll stay with the system I got now.
The issue will be moving all the nuts in the hose
The bigger and longer the hose the harder that will be
You will not be picking up one piece at a time, waiting for each to reach the barrel
You will want to support a continuous flow.
I think you need to try it, moving a significant weight at the same time will be difficult.
If you limit the amount of nuts in the hose at any one time, it might work.
On 12/26/2013 8:47 PM, firstname.lastname@example.org wrote:
So far, with the species locally produced, I have not had a jamup in the
hose, unless you count the kinks in the hose where it restricts flow,
and then releases all the nuts once the kink is straightened. We do
have some "mammoth" pecans (a grade given by USDA for very large very
long pecans) but I have not personally vacuumed any of those yet, just
bought them from property owners. There is a local variety that is
round, and approaches 1 1/4" in diameter with the husk on. Those fly
right through the hose. I did have to make a vee shaped protector for
the air filter that the nuts hit at full speed before dropping into the
body of the vacuum. I am using a very large Shop-Vac model, and have a
Craftsman with two motors that I can use on top of 55 gal barrels, but I
have not tried that one yet, as it has a bad hose, and I have not
replaced it yet. It does have awesome suction, more than the Shop-Vac,
so it will be interesting when I do try it. It will also be easier if
my long hose idea works, and I can suck them directly into 55 gal
barrels, and change barrels quickly, and leave the barrels on the truck
or trailer. The collapsible style hose will compress slightly when at
high vacuum, while PVC would not. As I say, so far, so good.
There are larger vacs made for handling grain. One brand is
Walinga. I don't know if the hoses would work for your use but they
might be worth looking at for ideas if nothing else. I think they use
sections of aluminum pipe for longer distances and just use the hose at
Sounds spendy to me. I have a total of $35 in both of these, if you
don't count the filters. The Craftsman has paper filters, if I can find
some. If not, I probably could just cut up any old vacuum filter with
that type paper.
Do you even need filters? If so, a separator before the vac seems the
way to go. Removing the filter will allow any dirt to pass through
(not clog the filter) and it will remove some restriction. You really
don't need the shop vac's can, either. Something like a dust
collector may get higher air volume. Something like:
Drove a forklift one summer as a longshoreman in Galveston, Texas
handling cotton bales. It had a squeeze apparatus. Those honking bales
were heavy. If they ever caught fire, it took weeks for them to go out,
as they had to separate all the cotton because it just kept smoldering.
Soaking it would not put it out. There were cotton fires regularly at
the docks. We'd put on a Scott Pack, and try to get the smoldering
bales out of the building, and separate good from smoldering.
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