Design of Belt Conveyors Step #3 Checking Out the Power ©2012 Dr. B. C. Paul Note – Material in these slides include screen shots from the program “Belt.

Design of Belt ConveyorsStep #3 Checking Out the Power

©2012 Dr. B. C. Paul

Note – Material in these slides include screen shots from the program “Belt Analyst” by Overland Conveyors. Credit for program and interfaces are given to Overland

Conveyors. Procedures taught and many tables used were developed by the Conveyor Equipment Manufactures Association. The author also referenced previous notes

developed by the author.

Let Check Out Motor Sizes, Belt Type and

Brakes

Our Belt is 503 lbs per inch width (the way belt strength is measured) – it runs a 88% of ratedStrength. We have a 250 HP motor that runs at 72% of name-plate

This shows the stress profile onThe belt over the entire length

Belts That Roll Up and Down are Tricky

There maximum stress may not occur atThe drive pulley and may move aroundDepending on how the belt is loaded.

We Will Have The Computer Check Horsepower While the Belt Loads

and Unloads

I went to the motor tab

I drop the EditMenu

I Select Loading

On the side ISelect Carry

On the sub-subMenu I order toLoad up and thenUnload the belt.

Step By Step Simulation Sets Up

I have ordered it to pause if IOverload by motor, belt, orTake-up so I can see theCondition and take action.

It Steps Through Loading and Unloading

During Load On Simulation

My motor which had a steady state loadOf 72% reached 92%

My belt which had an 88% steady stateLoad at one point reached 97%

I did not need brakes at any point.

I Simulate the Conveyor Unloading

Again everything checks outOk

Lets Check Out Only Inclines Loaded

Looks Like We Are In Tolerance

Only Declines Loaded

Life is Still Looking Good

We Could Try Some Other Things

• If this were a decline I could play with temperature since it impacts friction

• What happens if I get sloppy on my maintenance with rollers and alignment?

• What happens if I end up with about the same volume on the conveyor but I end up cutting a lot of roof?

I’ll Go to My Idlers Page

I Will Allow User Access to All Database Parameters

I’ll Go After Alignment and Seal Drag

Now Theres a Piece of Well You Know What Maintenance

Oh My Gosh!If it stalls in this conditionI never get it started

Belt at 114% (if it were newIt might not break)

Motor at 123% - your dead

Take-up at 116%

Step Up the BeltPick the belt Icon on the Left

Allow User Access to Data Base

Pick the Next Belt Duty Up

Go To The Motor

This time there is not a databaseOf common sizes.

Common Motor Sizing

• From 75 to 150 in steps of 25 hp

• From 150 to 500 in steps of 50 hp

• From 500 to 700 in steps of 100 hp

• From 750 up in steps of 250 hp

I’ll Put a 300 on It

I’ll Set the Take-Up to 23,000

My Worst Case RunI’m at 102% and 103% - I’m fairly sureI can live with that.

If I Wanted to Try My High Roof Rock Scenario

On material tabSet Density to reflectHigh roof rock content

Set the tons per hour to reflect whatYou think you would produce if youWere cutting a lot into roof.

Well Now the Time Has Come to Shoot the Engineers and

Start Production

Under Profile we can find our belt length and idler spacings.

On the Idler Tab We Can Find the Number of and Ratings for

Our Idlers

On the Belt Tab We Find the Belt Type and Length

Under Drive We Find Motor Size, Speed and Lagging for the Drive

Pulley

Under Pulley You Find the Size and Lagging for Your Pulleys

And a Little Graphics Bonus

Right click on the conveyorProfile and it offers you2D or 3D graphics.

Might Get a Little Coolness for Your Presentation to the Board

A Side Comment

• Sometimes for long runs of big lifts (such as a slope) you may need to dual drive– Dual drives allow you more wrap than you can

get with one drive– Can also spread out your motor horsepower

• If the drive motors are together at one service location the secondary drive motor will be much lower HP than the primary

If You Need to Go Dual Drive

On profile if you click insert drive it will put in a 2nd (or 3rd) drive

Now to Include You• Your Unit Project

– Your coal mine has a slope from a depth of 800 feet.– Design a slope belt conveyor to bring up 1700 tons per

hour• Provide me with a supply list

– How much belt of what width and rating do you need?– How many carry and return idlers of what specification

and rating do you need?– What size and lagging do you need on how many of

what type of pully?– What size and speed of motors do you need.

Continued

• Explain to me how your conveyor is laid out and what you did to make sure your conveyor could handle any foreseeable duty

• Provide a copy of Belt Analyst file or files (in case you cannot get to the top with just one conveyor)