Dear Bharat,

The third choice you should consider is the capsule pipeline system.

You will be able to investigate an operating system in Japan at <www.capsu.org> the link will take you to a system used by a cement manufacturer to move limestone from a quarry to a cement plant- this system replaced a railroad and it is very clean and energy efficient-with energy costs rising of course these systems are even more economical.

one more site I want you to look at is:

<www.pneutrans.net>

They have an online form that you can fill out and they will give you a no obligation quote for one of their systems.

Having been working around conveyors for over 22 years I can I honestly say in this mechanics opinion that this is the way to set up an

aggregate delivery system.

By using synchronus motors in the system you will be able to capture electrical energy while the motors fans are running in reverse from the forward motion of the capsules moving in the system your electric bill will also be reduced as well since the synchronus motor is feeding powwer back into the grid.

Also the longer the system is -in your case 5 kilometers it it more more economical than a conveyor of either type.

the limiting factor is tonnage as it is based on a system that moves 100000 tons annually the more tonnage the more economical it is.

The adavantages are many as the system is running 24 hoursa day unattended and there is no pollution as all the air in the system is filtered before it is discharged.

The system has no idlers, no conveyor belt,

no splices to leak, no tail pulleys to shovel no greasing, no drive units and only one or two power units for each system- you need two -one for both ends and a booster system depending on system length.

Please check out the site and you will be surprised to see how much material 16 inch or 24 inch capsule pipeline system will move.

one more thing -capsule pipe lines have been in use fore over a hundred years now in one form or another as is described at www.capsu.org

lzaharis ■

Dear lzaharis,

I looked at yur referenced websites for the pneumatic capsule conveyor. I did not see any reasonable reference list of installations that provide some assurances of competitive capital and operating costs, reliability and client satifaction.

One point of concern is the ability to easily clean the inside so that it does not aggolmerate.

Do you have such?

We studied this concept for the Skyline mine downhill in Utah. This is now a pipe conveyor L= 11000 ft long, 600 ft drop. The capsule did not come close on capital cost. It did not make the short list.

Maybe they have developed new methods, machines, etc that substantially improve total cost of ownerhsip. ■

Dear Bharat

I would say you cannot justify anything but a conventional conveyor for your application as it is perfectly normal (and there are probably thousands of them similar to your one).

The pipe conveyor is normally about 20 to 25% more expensive, and is useful for tight horizontal radii etc., which I assume you do not need.

Keep it simple

Regards

LSL Tekpro ■

Dear Sir,

both solutions may work depending on the geography. There are references for both product types for even much longer distances. So from a simple view of cost caculation a troughed conveyor is usually cheaper. If you can avoid an additional transfer point with all costs involved there by using a pipe conveyor the picture may change.

Holger Lieberwirth ■

Dear Shri Bharat,

The conventional belt conveyor and pipe conveyor have their area of application. The choice depends upon which considerations are dominant from buyer side.

You have not mentioned the size of the material. Mostly, it would be lime stone from secondary crusher, possibly size less than 100 mm.

If the conveying route us having sharp curvature in vertical and particularly horizontal plane, then it would be easier to fit pipe conveyor in to this route. If the material is powdery, then pipe conveyor will prevent the material loss due to wind etc.

If above requirements are not present, then you can make a choice between the two depending upon price and other technical considerations.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Somehow, the extra advantages that a Pipe conveyor offers do not seem to have featured here. So, here goes some of them -

1. High idler life - since there is practically no contact between the dirty side of the belt and the idlers

2. Single side walkway possible - imagine the amount of steel saved !

3. Covered system - hence no canopy required, at least for limestone handling

Kayem ■

Dear Kayem

My views are as follows

With pipe conveyor I agree pipe forming idlers are not in contact with dirty side of belt and idler life is increased , however no of rollers may be 2,5 to 3 times higher than conventional conveyors

For small dia pipe conveyor walk way can be provided on 1 side sme is applicable for conventional conveyors having small belt width. in pipe conveyor walkway on both sides should be provided to attend rollers of opposite side of wlkway

Yes material transportation in pipe conveyor is in side enclosed belt and don’t require cover. However conveyor belt is exposed to sunlight and deteriorates faster if cover is not considered

In case of open conveyor Pipe conveyor rollers are exposed to direct rain

A R SINGH ■