Aside from the real design issues, an 84 inch (2100 mm) belt, running at 1400 fpm (7m/s) could handle 60 million tons per year.

A pipe conveyor would not be practical for such an installation. Do not discount what a conventional belt can navigate. ■

If one could design a pipe conveyor of unusual performance, the producion capacity might reach 36 milion tons per year with the general specification of:

1. Pipe diameter ...................................... 30 in. (750mm) requiring a 100 in ( 2500 mm) wide belt

2. Speed ................................................ 1400 fpm ( 7m/s)

Note conventional conveyors have even greater capacity where the pipe conveyor has not been designed in this performance range.

If you stick to standard capacity pipe conveyors the annual production would be reduced to 21 million tons/yr. with:

1. pipe diameter ..................................... 24 in (600mm)

2. speed ................................................ 1000 fpm (5.5 m/s)

Others may advance my knowledge. The above are rationalized at 6000 operating hours per year. ■

Dust from windage and return configuration can be controlled on a conventional conveyor to acceptable standards by applying prudent engineering. We are not talking about catalog engineering.

A word of caution on pipes. THere can be spillage if you do not apply special techniques. There are a number of pipe conveyors that do have such issues that are not published. Clients tend to be mum on the subject. ■

Greetings from the frozen Eastern Wilderness,

I read with great interest your recent posting. If you are serious about investigating this possiblity you should investigate the capsule pipeline system developed by the folks at pnuetrans.net.



Even with the economies of scale promised by the continous extraction of bituminous coal in your region you have extensive planning ahead.

The big question is how much processing do you intend to do before transport?

1. The extraction of shales and other rock must be done before anything else

to reduce material weight and contaminants.

2. Washing, screening and dewatering using a vacuum filter or centrifuge must be done before transport as this will greatly improve product quality and flow of product-by washing with a floatation thickener circuit you remove many contaminants that would otherwise be burned during energy extraction. this also helps to remove volatle organics before burning soft coal.

3. The capsule pipeline system should be seriously considered as it is more efficient than conveyors, trucks and rail. The capsule pipeline system uses compressed air to push and pull the tubular haul trucks through the pipeline to its destination.

The advantages for a capsule pipeline are that they can be installed almost anywhere, in the air under water or highways and up or dowm mountains for hundreds of miles. The system is unaffected by weather as it is not exposed to the environment.

The most efficient way to install any system is to install it in a straight line.

The capsule pipeline system allows you to use conventional pipeline installation methods to install its system- this will allow you to go in a straight line anywhere using pipe ramming and small diameter tunnel boring machines which will also pull the pipe into the bore at the same time. Curves for the capsule pipe line can be no smaller than 60 times the diameter of the pipe- always remember:

FRICTION IS THE ENEMY NO MATTER WHICH SYSTEM IS CHOSEN !!!!!!!!!!!!

The straighter the length the more efficient the capsule pipeline.

The big advantage with the capsule pipeline is that the electrical connections are only required at the loading point, discharge point and booster stations where needed.

The other electrical advantage allows you to recover the energy in the discharge air by creating electricity

driving the discharge blower in reverse.

If the power drops out the capsule trains slow to a stop due to the resistance of the air in the pipeline and the seal created by the trains gasket that runs around the edge of the truck

and allows a seal between the truck and the inside pipe diameter.

When the power comes back the trains restart their journey as before.

The system uses low pressure high volume air to propel the capsule trains in both directions. The system will allow you to run as many unit trains as required for your product output in one pipe line. The dual pipe line set up allows for continous loop operation for the pipe line which would be ideal in this case due to the amount of ore available.

Loading of ores is accomplished with a

metering valve under a hopper, the unloading is acomplished easily as the hopper on the capsule truck rides on swivel bearings on each end of the capsule truck- I am not sure as to whether they use a magnet, rotator, or pressure wheel driven to turn the hopper to turn and dump the hopper on the capsule truck. Before I forget the capsule trucks are supported by a set of wheels around the circumference of each end of the capsule truck-either 4 or 6 wheels spaced at either 90 degrees or 60 degrees each.

The system eliminates the need for troughing and return idlers, conveyor belt and all the wiring for multiple drive units, hydraulic take ups, emergency stop systems. The possibility of a belt fire is also eliminated. The system is also self cleaning as the dust is propelled along the system to either end and collected and filtered at both ends.

The big thing is that this system runs unattended and with less personell and maintenance. the efficiency of scale with this system are also much in its favor due to increasing energy costs.

loading at the mine mouth is also easily accomplished as well due to the flexibility of the system. Propulsion speed for the system can also be increased as needed.

I bet you never expected to get this information :^0

Do you have any underground mining experience relating to this?

lzaharis ■

lzaharis,

I have been involved on studies of this system over the years. One big obstacle has been the reference list to substantiate and validate the designers claims. Is there now a serious reference list of installations that can atest to your claims?

Is so, could you share the specifications, dates, and locations with the forum? ■

send me your e-mail address and we can discuss it further in more clarity.

lzaharis@lightlink.com ■

If the coal is dry and has a broad particle size distribution, dense phase pneumatic conveying will be better than mechanical type of conveyors. For such long distances, several drop-out stations would be needed. But investment and opearting costs will be much less.

Regards,

A. T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting Co.

polypcc@aol.com

Ph and Fax: 304 346 5125 ■