Dear Mr. Dalwadi,

Please inform the length of this particular belt conveyor. These conveyors will be in series. The yard conveyor is likely to be longer and for that the speed will not pose problem. How about other associated conveyors?

Regards,

Ishwar G Mulani.

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

Email : parimul@pn2.vsnl.net.in ■

Dear Mr. Dalwadi Udit:

It is possible to design a troughed belt conveyor to handle speeds of 3.5 m/sec and above. A number of the lake boats on the Great Lakes (USA & Canada) utilize troughed belt conveyors running at speeds in excess of 5 m/sec. These vessels carry a variety of material -- including limestone.

Of course, it is important that the conveyor framework, idlers, and pulleys are of sufficient strength and/or size to cope with the vibrations induced by high speed conveying. It is also wise to consider the safety implications which greater speeds will induce.

Hope this helps. ■

Mr. Udit,

You can go faster clear up to 6.5-7 m/s depending on the idler specifications. What is the point? You need about 750 mm belt when running at 5.5 m/s. This gives a 98 mm edge clearance.

With a long belt, the higher speed can yield capital cost benefits. You have to optimize the process of CAPEX and OPEX for long belts.

The design you posted is in the ball park. It gives a 150 mm free edge clearance distance which is quite liberal. If you have pick the 1000mm with and 3.5m/s speed, what is left to do?

If you have to load on 16 degrees, then the speed is an issue as is the design of the transfer chute.

You can go slower, given the 1000 mm width. You could go to 3 m/s. Idler trough angle is assumed to be 35 degrees. A 45 degree trough might be better, if you want a greater idler spacing. At 3m/s, yields a 126 mm edge clearance.

Belt construction and idler spacing also gets in the mix. This leads to Mr. Mulani's question on belt length.

There are other issues when considering the final design.

Lawrence Nordell

Conveyor Dynamics, Inc.

www.conveyor-dynamics.com ■

Another note.

Mr Mulani hinted at the problem with "other belts".

Higher speed may give you grief when trying to stop them without piling up in the transfer chutes. Greater brakes and or flywheel conditions may become issues to control spillage at the transfer area.

Transfer chutes take greater wear when controlling greater velocity. Dust and noise can become an issue.

LKN from CDI ■

Note 3:

If your configuration is a yard belt to stacker, and the stacker must cast to give the maximum stockpile volume, then you want to go fast with the stacker.

You also want to go fast with the yard belt to properly control the flow of limestone in the chute. To do this you need a curved chute to maintain the kinetic energy from belt to belt.

We can help you get it right.

LKN from CDI. ■

The speed of 5 m/sec is common in many Coal Mines in Indonesia.

But the complaints are the chute life and the Idlers life.Otherwise it is practical and many such plants in operation.

We are involved in such a coal mine capacity increase by way of increasing speed, Chute works and related alterations.

regards

s.m.subra ■

Belt speed 3.5 mps is not unusual and conveyor can be easily designed for that. But as I hinted, you may need to tackle the issue in totality of plant (i.e. related conveyors system).

Speed also depends upon the quality of design and quality of components, machinery, and structures.

Regards,

Ishwar G Mulani.

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

Email : parimul@pn2.vsnl.net.in ■

Dear Mr. Dalwadi Udit,

In my earlier two messages, I have already given some views on this topic. The belt speed is an ever green subject for all people concerned with belt conveyors, and often with differing views. Therefore considering importance of this issue; I am adding following information for better understanding.

The belt speed issue is somewhat similar to issue of car speed. If you put question as to what is the permissible speed for car, a person from some place will say upto 200kmph is quite common, and we are widely using it. Whereas, some person from other place will say right speed is 100 kmph and anything beyond is madness. Then, whether the speed in question is with reference to highway or in-city is another point (i.e. long distance conveying or group of inter connected small conveyors). Therefore, the answer is subjective to quality of car, road, maintenance, replacement, sense of discipline / responsibility etc.

Similarly, the allowable belt speed for conveyor is subjective in nature. The idlers with least imbalance, least out of roundness, belt of uniform carcass, excellent joint, idlers and components proper installation on xyz co-ordinate (all above in absolute numerical terms), proper limitation of belt sag, proper design for conveyor, and so on will affect the decision on belt speed.

The present day more speed compared to speed in 60s/70s, is reflection of improved quality (i.e. my above statement). Therefore, conveyor designer is to decide for speed, in context to technical conditions. It needs to be decided in specific context.

I also clarify that if there is belt speed limitation of say 3.3mps; no great change will occur whether it is 3.0mps or 3.6mps. That is the speed limit is not a rigid boundary. The belt speed is an important issue, and unfortunately it is not without complexities as it involves industrial quality culture from all concerned (i.e. designer, procurements, installation, maintenance supplier, user and so on)

For material like limestone of (-) 75mm size, the material itself does not put restriction on speed 3.5mps, or even much higher than that. However, issue to be tackled in totality, appropriate to technically relevant conditions, as applicable for you.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyor

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in ■

Dear Mr. Nordell and Mr. Mulani,

I believe both of you have much experience in dealing with high speed conveyors. However, from the discussion, I have not seen any specific information regarding those conveyors out there. Please could you mention several conveyors having speed more than 8 metres per second with the site/company name opertaing them? The reason I am searcing this sort of information is the intention to look at overland conveying speed up to 10 m/s.

Thank you for any info you might have

Best regards, ■

Mr. Sinaga,

I am familiar with:

1. KPC installation as I was the design auditor for CRA

2. Mr. James speed increases to > 7 m/s

3. 13km steel cord belt cable failures -- I am interested in your fix

Higher speed conveyors that are or maybe still in operation:

1. 8.4m/s Selby in the UK installed in ~1984

2. 12 m/s tested in South Africa on the Power Strip for Eskom-- the design has some flaws which I am not aware of the fix if any.

3. 10 m/s in Germany at the Lauchhammer lignite open cast pit outside of Leipzig.

4. > 7m/s at Alcoa's Pinjara overland system in Australia -- they where/are studying going to ~9 m/s.

5. Lauchhammer was designed by the East Germans before the wall came down. West German lignite mine experimented with speeds to 7.5m/s -- today that number may be higher.

There are very important issues that need inspection to elevate the speed to ~10 m/s:

1. Idler diameter, eccentricity and balance criteria with speed

2. Idler spacing may need adjustment -- will be difficult with the present idler frame design

3. Proper speed to achieve increased tonnage may differ from obvious selection to achieve tonnage

4. Idler support frame compliance(stiffness) at nominated speeds, or as noted above to change speed to satisfy frame design, or modify frame design to meet new stiffness criteria

5. Associated natural vibration sympathetic harmonics between belt, idler frame and transom, spin frequency proximity to belt axial and transverse natural vibration modes

6. Change in idler life and maintenance associated with the above

7. Noise associated with the above

8. Volcanic action of coal on belt with improper frame stiffness

7. Maintenance of belt alignment over swamp area -- high speed will increase sensitive

9. Improved knowledge of dynamic shock wave control is required especially during stopping i.e. KE= (mv^2)/2 -- the system will need to be retuned with probable changes to drive mass, takeu-up control, idler spacing, .......

10. Transfer chute design

Sounds like an interesting project. KPC has been pretty aggressive in getting good value out of the upgrades to the system. I have a keen interest in you success. I hope we can stay in contact.

Regards,

Lawrence Nordell

President

Conveyor Dynamics, Inc.

1111 West Holly Street

Bellingham, WA 98225

USA

phone: 360-671-2200

fax: 360-671-8450

email: nordell@conveyor-dynamics.com

website: www.conveyor-dynamics.com ■

You might want to research Capsule pipe lines,

Contact The folks at <www.Pnuetrans.net>,

The freight pipeline capsules run over 25 miles

per hour and they cost less to operate. With the energy costs required to operate a belt conveyor the capsule pipeline is becoming more and more economical, an added plus is the fact that you can recover energy from the synchronus motors and return it to the grid while it is running in reverse-try doing that with a belt conveyor!!

To see an existing capsule pipeline that is currently operating in Japan at a limestone

quarry and delivering limestone to a cement

plant please visit the <www.capsu.org> site which has a wealth of information about the past, present and future of capsule pipelines.

I became familiar with the pnuetrans folks early in 1994 and after having to deal with underground

conveyors it is the way to go in my opinion.

people forget that pipelines pump petroleum, water and natural gas very dependably. The capsule pipeline reduces labor, operating expenses and maintenance. ■

Originally Posted by I G Mulani

Dear Mr. Dalwadi,

Please inform the length of this particular belt conveyor. These conveyors will be in series. The yard conveyor is likely to be longer and for that the speed will not pose problem. How about other associated conveyors?

Regards,

Ishwar G Mulani.

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

Email : parimul@pn2.vsnl.net.in

Dear sirs

I came across the statement being used for sacker recliamer being used in coal handling plant ie (ratio of track gauge to boom length shall be 5)

What is significance of ratio between track gauge and boom length ? ■

Originally Posted by guddu

Dear sirs

I came across the statement being used for sacker recliamer being used in coal handling plant ie (ratio of track gauge to boom length shall be 5)

What is significance of ratio between track gauge and boom length ?

You insist on plonking irrelevant questions inside ongoing threads. Is this a deliberate attempt to confuse? After 3 recent farsical postings I request Moderator Review of your behaviour. ■