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 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 rated Strength. We have a 250 HP motor that runs at 72% of name-plate This shows the stress profile on The belt over the entire length

Belts That Roll Up and Down are Tricky There maximum stress may not occur at The drive pulley and may move around Depending 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 Edit Menu I Select Loading On the side I Select Carry On the sub-sub Menu I order to Load up and then Unload the belt.

Step By Step Simulation Sets Up I have ordered it to pause if I Overload by motor, belt, or Take-up so I can see the Condition and take action.

It Steps Through Loading and Unloading

During Load On Simulation My motor which had a steady state load Of 72% reached 92% My belt which had an 88% steady state Load at one point reached 97% I did not need brakes at any point.

I Simulate the Conveyor Unloading Again everything checks out Ok

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 condition I never get it started Belt at 114% (if it were new It might not break) Motor at 123% - your dead Take-up at 116%

Step Up the Belt Pick 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 database Of 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 Run I’m at 102% and 103% - I’m fairly sure I can live with that.

If I Wanted to Try My High Roof Rock Scenario On material tab Set Density to reflect High roof rock content Set the tons per hour to reflect what You think you would produce if you Were 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 conveyor Profile and it offers you 2D 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 2 nd (or 3 rd ) 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)