Silo Capacity

hi gents,

im not sure if im doing this correctly.im working out the capacity of a silo with a cone at the base.

equations are as follows.
cone:
v = 1/3 pr^2 * h
cylinder
v = pr^2 * h

total volume of silo = (cone+ cylinder) * density of product(powder)

is this correct ???

http://www.math.com/tables/geometry/volumes.htm

V_cone = correct
V_cylinder = correct

V_total= V_cone + V-cylinder

total mass = V_total x density

What ivo.maenen is trying to say is that most of your formula is right. however, if you just want volume then add the volume of the cone and the cylinder together. If you actually wanted mass of product (i.e. kilograms) then yes, you could estimate it by multiplying by the powder density. However, since the powder may end up being compacted quite a bit near the bottom (depending on the height of this silo and the physical properties of the powder), this could lead to a large margin of error.

Hope the weather's lekker in Durban, grew up not far from there and I miss it!

Sup Saffa, im from Port Shepstone, im sure u know the place, pleasure meeting someone here. How long are you abroad know???

@Saffa. Thats correct, because we are loading this product into tankers and the weight loss isn't correct when the trucks are on the weight bridge. so an alternative into reducing this error is keep correcting our calibration / or install a correction factor on the plc...

There is more to this.

Depending on the material in the silo, if it is granular, the top surface will not be flat if it is filled from the top (non-liquids invariably are).

So you'll have a cone at the top as well, the angle of that cone will depend upon the "angle-of-repose" of the material. Common data is available on the web, if you can't find your own material, you'll have to measure it somehow.

Even worse, sometimes that top-surface cone isn't centred in the silo either, so where you are measuring your h will change things.

For a centre-filled silo, here's on online calculator