Pipe Conveyor Design Question
Mr. Mallick,
The term 2*T*sin(q/2) is merely the load exerted on a roll or idler when a tensioned belt (with tension T) is deflected over the roll or idler by the angle q. If this is a circular curve, vertical or horizontal, the idler load can also be expressed as P=(T/R)*Si, where: P is the idler load, T is belt tension, R is radius of curvature, Si is the idler spacing.
I assume that Ky is the complex coefficient which accounts for material shear and shear, flex, roll imprint resistance at the belt. Ky is itself dependent on tension and idler spacing and in more complex models it is also dependent on roll diameter, rubber characteristics, cross-sectional shape and material confinement.
The equations are a bit more complex but this is likely a good approximation for the Ky part of the additional resistance that is due to the curvature. Additionally, Kx must be increased for the addittional radial load though at .00068*(T/R) it is not likely a significant increase. The actual computation of Ky for the Pipe Belt is the bigger challenge.
Joseph A. Dos Santos, PE ■
Re: Pipe Conveyor
Mr. De Santos explanation is correct. For the pipe conveyor, this additional idler pressure and resulting belt indention and flexural rolling resistance drag, must also be considered for all convex and concave vertical curve radii. Conventional belts do not have losses for concave radii. ■
Pipe Conveyor
Dear all,
I am new to the design calculation of pipe conveyor motor power requirement.
Kindly tell me what will be the effect of a horizontal turn in the pipe profile towards the belt power requirement. I have come across a formula which indicates additional power requirement for horizontal turns are as given below:
T1 (in Kg) for horizontal curvature = Summation of {2*T*Sin(q/2)*Ky)
Kindly confirm that whether the above formula is correct. In case this is correct, what is q? Is the belt lapping angle? Or the angle of horizontal curvature?
I guess that radius of curvature/angle of the horizontal turn should have some effects on the above formula. Also I understand ‘T’ is the local curve tension. Kindly confirm.
Also, I would be interested to know if the carrying side idlers (hexagonal) are at 2m spacing, is it required to reduce it to say 1.2 m while entering the idler spacing values in tension calculation program?
Looking forward to your advice.
Regards,
S.S.Mallick
S.S.Mallick (Design Engineer- Mechanical)
Development Consultants Pvt Ltd
24-B, Park Street
Kolkata-700016, India ■