Double Belt Press Conveyor Design - Sizing Drive Motor 2

[Ragool]

Hello all,

I need some help with determining the right formula to size the drive unit for a double belt press conveyor system. This machine is very similar to the Sandwich Panel production machines. I have uploaded an image for you to look over.

So, the top conveyor applies 5 psi of pressure on the bottom conveyor while conveying the product.

The general formula that I found on the internet is as below and I have simplified the calculation.(I am using arbitrary numbers in the formula)

Power Required = Belt Pull x Belt Speed
Belt Pull = Wm + Wb

Wm = Weight of the material = 100 lbs
Wb = weight of the belt = 20 lbs
Belt Speed = 5 ft/min

However, the above equation does not take into account the additional 5 psi pressure that is applied by the top conveyor.
The 5 psi pressure is applied over an area of 1000in^2.

So the applied pressure is = 5*1000 = 5000 lbs

Belt Pull = Wm + Wb + applied pressure

Now that significantly increases the Belt Pull and as a result, the torque required is high. So my question is, do I have to include the applied pressure into account here?

 

[3DDave]

Since the belts appear to have the pressure applied by the roller, in an idealized system, there is no increase to the belt pull. However, in actual use there is rolling friction and that depends on the number of rollers, the diameter of the rollers, the force applied to the rollers and how much elasticity there is in the rubber belt that the rollers are squeezing. Compare to the effort in rolling an office chair wheel on a floor mat.

 

[BEMPE16524]

basic foundation:

note: this is just a basic example.

R.Efendy

 

[dvd]

You definitely need to include compression forces in your calculations. Is this a steel belt? Are you running on rollers or sliders? The compression forces are the normal force and belt pull is perpendicular to this. Depending on whether you have a slider surface or idler supports, you will need a coefficient of rolling friction or a coefficient of sliding friction to calculate the belt pull associated with product compression. Also, note that product compression acts opposite to belt weight on the upper conveyor, so belt weight subtracts from compression force for the upper conveyor. It is additive for the lower conveyor.

IPCO and Berndorf are steel belt suppliers and should have good literature available on their websites. Sandvik is another name for steel belt literature, but I think they got incorporated into IPCO.

 

[dvd]

Some literature from Sandvik is attached

 

[Ragool]

I appreciate all your responses.

It is a kevlar belt with multiple rollers between the head and tail pulley. So, would it be accurate to update the formula as shown below?

Belt Pull = Wm + Wb + force applied * coefficient of roller friction

 

[dvd]

rolling friction coefficient has units, see below