Mr. Dey,

Have you considered the use of a DSI Sandwich Belt High Angle Conveyor for steep angle conveying as opposed to a pocket belt conveyor.

I would encourage a discussion on the benefits of such a system as opposed to the pocket belt conveyor. Just a few examples are:

- Unlimited conveying capacity, where with pocket belts there are limitations.

- A system suitable for the most rugged mine applications, yet gentle on sensitive and friable materials.

- High availability and low operating and maintenance costs.

- Smooth surfaced belts allow continuous belt cleaning by scrapers and plows. This also facilitates intermediate material discharge by belt plows, as appropriate, before and/or beyond the sandwiched part of the conveyor profile. Additionally, there is no carry back that will occur in pocket belts, especially with sticky or moist materials.

- All conventional conveyor hardware insures economy and fast delivery of replacement parts.

Dos Santos-design sandwich belt conveyors have been proven in more than one hundred successful conveyor systems installed throughout the world.

Please contact me if you would like more information.

Regards,

Amy Duncan ■

Kindly let me know whether there is any standard / reference available for calculation of Steep Angle Conveyor?

There are many kinds of 'steep angle conveyors' and the individual manufacturers are better able to advise. Because there are no standards there is no established recourse when things go wrong. However, such machines should incorporate as many standard components as possible. Even then those components are often used outside the standard application.

1. The Steep Angle Conveyor is a Sidewalls Pocket Belt Conveyor That is only one option.

2. I want to understand the Pocket Belt Capacity Capacity depends on the chosen device and its possible attributes.

3. How to arrive the correct belt Speed. If a belt is specially made then normal troughed belt speeds will not apply: neither will idler capacities etc etc.

4. I want to understand the Power requirement Power requirements are estimates whatever anybody tells you. Components are sized within manufacturing limits.

5. Normally Carrying Idler is provided at Tail and Head End(No idler at Tail end). Is not it recommended to use Idler throughout the length?Then why? Where did you hear that one?

6. Design of Deflector Wheel,Shaft,Beater Wheel All these are proprietary devices and no manufacturer is obliged to reveal his/her design criteria.

7. Selection of Drive components.Is is recommended to use Worm Drive instead of Bevel Helical as per standard practice? Worm boxes offer greater resistance to run-back because the worm is handed.

8. Designing of Layout ,i.e., designing of Deflection curve. Think about this one. If you have a deflection curve the how come you need no intermediate idlers? See [5].

9. Material TPH-150,Bulk Density-0.75,Belt Width-800 mm.Is it feasible to use 90 Degree Steep in this case? Before any body can say, what size material?

It seems that you are hell bent on a vertical pocket belt and looking for serious design input. You will never get this for free. Sidewall cleated belts use plain rollers: not idlers. Have word with Amy in the first place. She will be able to tell you the feasibility of 150th^-1.

As per CEMA 5th Edition,illustrative method being shown to calculate the Pocket Belt Capacity but no detail explanation exists. Why should there be? CEMA refers to a recommended practice for belt conveyors. Any data on cleated sidewalls etc are gratuitous. ■

Hello,

Earlier participant has also suggested steep angle conveyor as being made by M/s Dos Santos, as against ‘pocket belt conveyor’. The equipment purchaser can opt for either of the type as per his choice.

As for pocket belt conveyor capacity calculation (or sizing to suit capacity); the calculation principle is same as for vertical or inclined bucket elevator, i.e. bucket capacity according to surcharge filling.

Draw a horizontal reference line from bucket (or cleat) upper tip. Also draw a surcharge filling material line from same tip point, which will intersect to belt line or the cleat ahead. The material being contained within the belt line, cleat/s line and surcharge line, is material being carried by each pocket. The number of pocket discharge will be (Belt travel in one hour) divided by (Pocket / cleat pitch). The equipment hourly ‘capacity-capability’ = (Number of discharge) multiplied by (Material being carried in each pocket).

The above is for bucket elevator as well as pocket belt conveyor - elevator.

I have also taken reference to M/s ContiTech Germany publication 4h revised edition – 1990 (it is inclusive of German belt long time legendary name M/s Clouth).

In case of pocket belt conveyors, the belt carcass internal construction is specific to make and thereby internal tension distribution will be also accordingly. So pulley size, wheel size will be specific to the particular belt construction. Therefore conveyor / equipment design will have to go by the recommendation of belt manufacturer in this matter (i.e. wheel dia, pulley dia, etc.), because only belt designer / belt manufacturer has belt research and test data.

Regarding resistance / power calculation for such conveyor, the calculation procedure is primarily like belt conveyor. I do not have exact data about conveying friction coefficient for such conveyor. It seems approximately 0.075 will be safe enough. This is higher compared to usual belt conveyor conveying friction coefficient due to flexing of more rubber mass in complex manner, as the belt travels.

Also, often conveyors being steeply inclined, the Cos effect to be considered for calculation of ‘rolling’ or ‘main resistance’. Such Cos effect applies to belt and material moving mass, but not to idler moving mass.

In any case, for vertical portion of conveyor, there is no main resistance as per this Cos effect.

For other shallow inclined portion, if such finer aspect is ignored then the calculation will be on safer side.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling

System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Originally Posted by I G Mulani

...

... The equipment purchaser can opt for either of the type as per his choice....

...provided the material agrees. ■

Hello,

Referring to my earlier posting, I add following information.

For the conveyor which has inclination less than surcharge angle; the earlier said procedure is not applicable. In such case, the surcharge line will neither intersect belt nor the cleat ahead.

For the conveyor having inclination zero to surcharge angle, the material filling is considered parallel to belt line, upto cleat height.

In both the above cases 90% filling factor (or less) can be considered to account for uneven feeding (this filling factor value depends upon type and quality of feeding equipment at the start of flow path).

Such conveyor speed can range from 0.7 mps to 2.0 mps. It is influenced by:

- Conveyor inclination at feed point: Lesser inclination permits more speed. More inclination permits lesser speed. This is due to reason that as the inclination increases, the feed chute discharged material hits cleats and belt more severely reducing their life.

- Lump size: Lesser lump size permits more speed and bigger lump size permits less speed. This is to prevent damage to belt and cleats.

For such ‘Inclined fed’ conveyor; the speed can be approximately in the range of 0.7 to 1.5 mps depending upon inclination at feed zone and material characteristics.

For ‘Z’ or ‘S’ type conveyor, where feeding is on horizontal path, I have come across pocket (cleated) belt conveyors handling iron ore pellets (-) 65 mm at speed 1.5 to 2.0 mps in steel plant.

For specific application, refer to belt manufacturer for belt quotation and their suggested speed, as it has also relevance to their belt life and guarantee warranty aspects; and thereby partially concerned with the issue of belt speed.

It would be inappropriate for the conveyor designer to decide belt speed of such specialised conveyors, in isolation.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling

System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Originally Posted by subhashisskyisthelimit

Respected All,

I am a new comer in Bulk Material Handling Industry.

Kindly let me know whether there is any standard / reference available for calculation of Steep Angle Conveyor?

The following points may please be noted in this regard:

1. The Steep Angle Conveyor is a Sidewalls Pocket Belt Conveyor

2. I want to understand the Pocket Belt Capacity

3. How to arrive the correct belt Speed.

4. I want to understand the Power requirement

5. Normally Carrying Idler is provided at Tail and Head End(No idler at Tail end). Is not it recommended to use Idler throughout the length?Then why?

6. Design of Deflector Wheel,Shaft,Beater Wheel

7. Selection of Drive components.Is is recommended to use Worm Drive instead of Bevel Helical as per standard practice?

8. Designing of Layout ,i.e., designing of Deflection curve.

9. Material TPH-150,Bulk Density-0.75,Belt Width-800 mm.Is it feasible to use 90 Degree Steep in this case?

As per CEMA 5th Edition,illustrative method being shown to calculate the Pocket Belt Capacity but no detail explanation exists.

I would definitely appreciate if somebody gives a detail numerical explanation other than generalised concept of designing approach.

Thanks and Regards,

Subhashis Dey

Good morning Mr. Subhashis Dey,

I have the same doubts, I have same your own problems: there is no manual with the FORMULAS for the calculation of belt power and tension.

The calculation of power and belt tension of a "Z" shaped sidewall is NOT exactly like a "simple" sloping conveyor belt ...

At the moment we are always based on personal experience and exuberant powers, at this moment we want to improve the accuracy of calculation.

To improve it is necessary to have exact formulas based on exact experiences, this is what I expected from the various books while I found only generic indications ...

Dear Mr. Subhashis, have you solved your doubts?

Could you share your method and the documentation you found?

I thank you and I thank anyone who can help me with textbooks and tangible formulas ■

Manufacturers of proprietary equipment are not obliged to reveal the specific design details of their equipment.

The best you can expect is in the manuals which those manufacturers freely provide to customers & contractors. Often in the past I have had to specify equipment which was comfortable rather than state of the art simply because I could not find the information I needed. You gentlemen are asking for manufacturing detail information for whatever reason. You will find this impossible to obtain or if you do find something how will you know it is reliable.

One solution would be to get a job there & find out properly. ■

Hello, I thank you for the time you gave me with your answer,

but I must tell you that you have not been useful to me

I must point out that I do not claim anything, I have asked for a courtesy.

I did not ask a machine manufacturer to reveal his secrets, I was hoping to find (in addition to the manuals of Dunlop, Rulmeca and Phenix that I already have) manuals with formulas for calculations

I hope that my curiosity is not a source of problems for anyone.

Thanks again, see you soon. ■