Dear Wibo,

Conveyors can be designed of any length using CEMA 5th edition. There are many caveates you need to apply to keep the design within reasonable accuracy:

1. coal - not greater than 54 inch wide (1371 mm)

2. speed - not greater than 6 m/s

3. carry idler spacing - not greater than 2m

4. fabric strength to ST-1500 and steel strength to ST-3500 N/mm

Today, CEMA 5th edition is seen to be quite outdated, in terms of economic selection for: power, belt tension, idler selection, structural and civil costs. The penalty could be as great as 25% of the overall capital and >30% for operating costs on a 6 km overland. OK for estimates but not advisable for the fit for purpose installation.

Would you like some assistance? ■

Dear Mr. Wibo,

For designing long conveyor with CEMA method is laborious. I suggest you should follow ISO 5048 or DIN 22101. It will take less time & will give you good result. Wibo , I think you are a student or doing some paper on it? Give me more information about your conveyor , I will help you .

Regards.

Atanu ■

Dear wibo

CEMA 5th addition is not out dated maximum nos of conveyors are still designed by CEMA tnan any other method

There are continous improvements in belt conveyor technology and improvements will be indicated in CEMA 6th addition.

CEMA is book to understand conveying technology by bigners without understanding basic knowledge you can not design complicated conveyors.

long conveyors can also be designed by CEMA . However when you design long conveyors to the user following aspects are important

1 power consumption

2 smooth operation

3 lower per meter instalation cost

4 cost of material transportation / ton/km

long conveyor when designed considering above considerations requires starting and stopping engineering to have jerk free start stop with optimum belt tension , syncronising the speed of varios drives, selection of take up location , selection of no of drives and drive locations

To be comptetive due consideration is given how to reduce belt width which can be obtained by increasing speed, by reducing no of idlers by increasing idler spacing .

In long conveyor Design lot of expertise is required even you can save up to 30 percent installation cost and even up to 20 percent power rating by intellegent design

To reach at level to design 6 km long conveyor your initial guide will be books like CEMA, I G MULANI,ISO 5048 etc.

As only only few companies designs long conveyors it is there buisness and properity technology and may not like to share in forum .

All common practices of conveyor design are indicated in CEMA

A R SINGH ■

DEar Wibo:

CEMA method & limitations:

Please reread the prior posting:

There is no 54 inch belt width limit orlimits on other values noted. I claimed that if you design for greater values than noted the CEMA method may increase the capital and operating costs over more modern methods. I have published a number of these more modern methods as they apply to overland, curved and high powered belt conveyors. See our website as given below.

The CEMA 5th edition will still be used. THe 6th edition has some improvements. It also has a number of errors that are in the process of being corrected. We have notified CEMA that we believe the new power equation, in Chapter 6, needs to be modified. Its present form may produce significant design errors. ■