Dear Mr. A. R. Singh,

At Dos Santos International we are the world's foremost experts on the Sandwich Belt High Angle Conveyor technology. Our DSI Snakes are the latest and the most advanced in this technology. We note that though your profile data are very interesting your design capacity requirement is quite small.

The DSI Snake advantage is most pronounced when the design capacity is very high, hence our saying "THE GREATER THE LOAD, THE HIGHER THE LIFT, THE BETTER WE LOOK".

We will be pleased to make an offering of a DSI Snake Sandwich High Angle Conveyor for your consideration. For continued correspondence on our offering I will Email you directly at your Email address listed on your post.

Joseph A. Dos Santos, PE ■

Dear Mr. AR Singh,

The Decision to use a skip hoist or a Conveyor depend on the feeeding rate the Downstream equipment can take.

When you unload 12 MT in 1.2 mins it work out to 600 TPH

If it is Ok skip hoist can be justified as it will cost a fraction of the hi-lift conveyors.

If not you either have to provide a temp hopper and a skip hoist or go for Hi angled conveyors.

Thanks

Jacob ■

With the product size specified a conveyor/beltbucket elevator solution could also work. How about the moisture content. Sometimes iron ore is extremely sticky. This has to be considered in the selection process.

Holger Lieberwirth ■

Mr. Holger,

If the material is sticky than a Sandwich Belt system is preferred since it can be scraped continuously.

On the other hand a bucket elevator will accumulate the sticky material in its buckets and return it to the bottom, effectively chocking of its ability to carry any live material that will discharge.

The Sandwich Belt system will be the best when elevating sticky material. ■

Dear Mr. Dos Santos,

For sticky materials the use of a bucket elevator needs certainly carefull consideration. With special buckets a solution may be found for many applications. On the other hand with a belt bucket elevator only a set of bearings at the drive and tail pulley are required. Much less moving parts than with a sandwich belt conveyor. Respectively, the selection needs carefull consideration.

Holger Lieberwirth ■

Mr. Holger,

Your argument is no more nor less valid for the comparison of a bucket elevator against a conventional conveyor to acheive the same elevating height. Performance ie availability, operating and maintenance costs have never favored the bucket elevator, only the low initial cost favors the bucket elevator and this tends to be false economics.

Joseph A. Dos Santos ■

Dear Mr. Dos Santos,

your statement regarding operating costs of a bucket elevator is quite surprising. Beumer sold thousands of bucket elevators over the past decades into industries with highly abrasive products. We never heard any complaint, however, about high operating costs, large maintenance of spare part requirements.

The steel cord belts with cable free zones for the bucket mounting developed by Beumer and Contitech have been proven durable and reliable. These elevators operate 24 hours/day 7 days a week. We developed special systems to supervise the proper tracking of the belt and the clamping device since nobody was looking for the elevator any more after month and years of trouble free operation without any maintenance (contrary to our manuals which require regular inspections every 6 month).

Some of our elevators operate with the same belt for decades now. The tallest one with a CC-distance of 142 m has been in operation now for more than four years.

One of our customers in US replaced a sandwich conveyor by a bucket elevator since he faced severe problems with the loss of material while conveying straight up, thus creating a big mess on the ground. Due to ever changing conveying quantities the idlers simply lost theire compression force in time.

So, certainly the bucket elevator technology has its limits as every technology (and we are manufacturing troughed conveyors, pipe conveyors screw conveyors, flexowell systems etc. on our own). But high maintenance and operating cost or reliability are definitely not an issue for a well designed bucket elevator.

Holger Lieberwirth ■

Mr. Holger,

I have heard, from the sandwich belt customer (in the USA) that you mention, about the prgress made in bucket elevators. Nevertheless your offering for that project is based on only 40% fill factor.

That sandwich belt conveyor replaced a very troublesome bucket elevator system back in 1994.

It turned out to be a gross mis-application. Though the system was correctly sized (36" belt width) and designed for the customer's materials and thru-put speciifications, including a 3" minus material size, that customer sought to operate it continuously with material size to 12" minus. Indeed we could have designed him a sandwich belt system for those requirements as we have successfully for others. It would not be a 36" Belt Width system, and we must know the requirements ahead of the design.

Sandwich belt systems (developed by J.A. Dos Santos) have replaced numerous bucket elevators and pocket belts throughout the world. To-date the opposite has not happened. Indeed the USA system that you mention will be the first in the 23 years since the first commercial sandwich belt system by J.A. Dos Santos.

I wish you the best in this application.

Joseph A. Dos Santos, PE ■

Dear Mr. Singh,

I have seen your requirement. we manufacture steep angle conveyors and skip hoist.

I would suggest to go for steep angle conveyor.

Sufficient period had lapsed hence I think, you must have finalised the system. If you require, we will quote for the system.

Thanks

Ketan

Fairtech Engineeing Co. ■