Re: Looking For Power And Effort Calculation Manual For Steep A…
Hello,
The reader is to acquaint himself about the application, use and constructional aspects of steep angle conveyor from the relevant literature by the belt manufacturers and manufacturers of such conveyor. Here, it is understood that the reader is already familiar about such conveyors.
This reply deals with the following two main issues:
1) Steep angle conveyor sizing i.e. deciding the belt width, pocket width, speed, etc..
2) Calculation of resistances which are input for calculation of belt tension and power.
Conveyor sizing :
The belt conveyor capacity is calculated in a manner similar to bucket elevator i.e. material contained in each pocket. The pocket is formed by belt flat upper surface, 2 side walls and cleat/s, as against one bucket. The number of pockets discharged per hour is (Velocity v mps) x 3600 Divided by (Cleat spacing in metre).
The hourly discharge rate mtph = (Material weight kg in one pocket) x (Number of pockets discharged in one hour) Divided by 1000.
This value should be equal or greater than the required design capacity.
As for the material contained in one pocket, refer the sketch attached with this post reply at the end. The material volume contained in one pocket is the shown cross section area multiplied by the length of the cleat. Convert this into material mass kg in one pocket, by multiplying it with bulk density. The angle ‘beta’ is surcharge angle of the material, which could be say around 20 degree, etc. as applicable for belt conveyors. The angle ‘delta’ is conveyor inclination to horizontal.
The aforesaid sizing procedure (sketch) take reference to ContiTech Germany information.
The belt speed v could be in the range 0.5 mps to 1.5 mps depending upon the lump size. Bigger the lump, lesser is the speed.
For lumpy material cleat spacing should be equal / greater than 1.5 to 2 times the lump size (maximum corner to corner length of the lump). The cleat length (clear width between 2 side walls) should be also 1.5 to 2 times lump size as said earlier.
Conveyor resistances:
The conveyor resistances and power is being calculated in a manner similar to usual belt conveyor but with applicable conveying friction coefficient, etc. The carrying belt bottom side is moving on idlers like usual belt conveyor. So its conveying friction coefficient would be lesser than the return run. As for the return run, belt side walls are moving on rollers. In this case, the conveying friction coefficient will be more because it will have more hysteresis losses in rubber. One can design the steep angle conveyor taking the common average conveying friction coefficient as 0.10.
It is to be noted that this being steep angle conveyor, the dominant resistance will be lift resistance and thereby the conveying friction coefficient value as considered above for conveying will not have decisive influence. However, designer can take different value of conveying friction coefficient if he has specific data.
The belt pulley wrap resistance will be more because of thicker / heavier belt. One can consider this as 3 times the usual conveyor pulley wrap resistance.
The pulley turning resistance will be as for usual belt conveyor.
Such conveyor cannot have external scraper. So its resistance will be absent. It will have mostly one internal scraper and thereby its resistance will be applicable (as for usual belt conveyor).
Skirt board resistance can be taken same as for usual conveyor (safer side).
The pulley wrap resistance, pulley turning resistance, internal scraper resistance and skirt board resistance are additional to ‘main resistance’ calculated by conveying friction coefficient f = 0.10.
The belt width and its construction features will be as recommended by belt manufacturers. The belt width for inclined conveyor without snubbing / deflection on cleated side, is likely to be around 1.6 times cleat length and for Z-type conveyor it could be around twice the cleat length. Finally both these will be as given by belt manufacturers.
Steep angle conveyor inclination limitation arises due to provision of walkway on the sides for maintenance. At 55 degree incline, the ratio i.e. (Step rise) Divided by (Step width) becomes 1.42 which is quite high. Therefore for higher inclination the option is Z-type conveyor. In this case, the maintenance walkway will be for horizontal portion at lower level and horizontal portion at upper level. There is no need to go in vertical zone and hence any access is not necessary for this zone. The conveyor portion to be maintained in this zone is simply driven down or up at horizontal level when to be attended.
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
Attachments
steep angle conveyor belt (PDF)
■
Further References
There are several publications which have recently been resurrected by the efforts of Marcel D regarding all aspects of bulk solids handling.
Cleated sidewall belts are mainly addressed by Trellex/Flexowell, Mors & the articles are thorough, professional & essential reading.
Search & you shall find.
One thing about any vertical belt is guidance. Although the carrying rollers can be excluded throughout the vertical travel there should be some means to restrain a snapped belt. Failure will result in the creation of a conical pile on the floor. To limit the size of the pile it would help if the belt fall was arrested by simple low friction guides which limited the belt movement. These guides would stand clear of the belt while running but catch a falling belt & prevent further There would also be less work to restore the conveyor. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Re: Looking For Power And Effort Calculation Manual For Steep A…
Hello,
In the posting yesterday (21 January), I missed to show profile for belt along with the cleats used for Z-type conveyor (horizontal - vertical - horizontal conveyor). The attached sketch shows cleat profile for incline conveyor and also for Z-type conveyor.
Now, these sketches show material filling keeping 20 mm clearance at edge. The capacity decided by considering the edge clearance, should correspond to the design capacity.
Once the various resistances in conveyor are decided; the calculation of power and belt tensions at various points is a routine affair as for usual belt conveyor.
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
Attachments
steep angle conveyor belt section (PDF)
■
Re: Looking For Power And Effort Calculation Manual For Steep A…
Originally Posted by I G Mulani
The reader is to acquaint himself about the application, use and constructional aspects of steep angle conveyor from the relevant literature by the belt manufacturers and manufacturers of such conveyor. Here, it is understood that the reader is already familiar about such conveyors.
This reply deals with the following two main issues:
1) Steep angle conveyor sizing i.e. deciding the belt width, pocket width, speed, etc..
2) Calculation of resistances which are input for calculation of belt tension and power.
Conveyor sizing :
The belt conveyor capacity is calculated in a manner similar to bucket elevator i.e. material contained in each pocket. The pocket is formed by belt flat upper surface, 2 side walls and cleat/s, as against one bucket. The number of pockets discharged per hour is (Velocity v mps) x 3600 Divided by (Cleat spacing in metre).
The hourly discharge rate mtph = (Material weight kg in one pocket) x (Number of pockets discharged in one hour) Divided by 1000.
This value should be equal or greater than the required design capacity.
As for the material contained in one pocket, refer the sketch attached with this post reply at the end. The material volume contained in one pocket is the shown cross section area multiplied by the length of the cleat. Convert this into material mass kg in one pocket, by multiplying it with bulk density. The angle ‘beta’ is surcharge angle of the material, which could be say around 20 degree, etc. as applicable for belt conveyors. The angle ‘delta’ is conveyor inclination to horizontal.
The aforesaid sizing procedure (sketch) take reference to ContiTech Germany information.
The belt speed v could be in the range 0.5 mps to 1.5 mps depending upon the lump size. Bigger the lump, lesser is the speed.
For lumpy material cleat spacing should be equal / greater than 1.5 to 2 times the lump size (maximum corner to corner length of the lump). The cleat length (clear width between 2 side walls) should be also 1.5 to 2 times lump size as said earlier.
Conveyor resistances:
The conveyor resistances and power is being calculated in a manner similar to usual belt conveyor but with applicable conveying friction coefficient, etc. The carrying belt bottom side is moving on idlers like usual belt conveyor. So its conveying friction coefficient would be lesser than the return run. As for the return run, belt side walls are moving on rollers. In this case, the conveying friction coefficient will be more because it will have more hysteresis losses in rubber. One can design the steep angle conveyor taking the common average conveying friction coefficient as 0.10.
It is to be noted that this being steep angle conveyor, the dominant resistance will be lift resistance and thereby the conveying friction coefficient value as considered above for conveying will not have decisive influence. However, designer can take different value of conveying friction coefficient if he has specific data.
The belt pulley wrap resistance will be more because of thicker / heavier belt. One can consider this as 3 times the usual conveyor pulley wrap resistance.
The pulley turning resistance will be as for usual belt conveyor.
Such conveyor cannot have external scraper. So its resistance will be absent. It will have mostly one internal scraper and thereby its resistance will be applicable (as for usual belt conveyor).
Skirt board resistance can be taken same as for usual conveyor (safer side).
The pulley wrap resistance, pulley turning resistance, internal scraper resistance and skirt board resistance are additional to ‘main resistance’ calculated by conveying friction coefficient f = 0.10.
The belt width and its construction features will be as recommended by belt manufacturers. The belt width for inclined conveyor without snubbing / deflection on cleated side, is likely to be around 1.6 times cleat length and for Z-type conveyor it could be around twice the cleat length. Finally both these will be as given by belt manufacturers.
Steep angle conveyor inclination limitation arises due to provision of walkway on the sides for maintenance. At 55 degree incline, the ratio i.e. (Step rise) Divided by (Step width) becomes 1.42 which is quite high. Therefore for higher inclination the option is Z-type conveyor. In this case, the maintenance walkway will be for horizontal portion at lower level and horizontal portion at upper level. There is no need to go in vertical zone and hence any access is not necessary for this zone. The conveyor portion to be maintained in this zone is simply driven down or up at horizontal level when to be attended.
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
Thank you very much eng Mulani, from your answer I understand your great experience,
the answers are concrete and direct as like me.
Thanks again for your help. ■
Re: Looking For Power And Effort Calculation Manual For Steep A…
Let me check it, very good share, thank you. ■
Re: Looking For Power And Effort Calculation Manual For Steep A…
thank you so much for such a nice sharing ■
Re: Looking For Power And Effort Calculation Manual For Steep A…
1) Steep point transport measuring for example choosing the belt width, pocket width, speed, and so forth
2) Calculation of protections which are contribution for count of belt pressure and force. ■
Trade Off Soda Ash Transport
I work for Worley Argentina. We are designing a lithium carbonate plant for liex.
The main input of production is dense ash soda which for us is an imported product. Soda ash is transported by ships in bulk. In the arrival port we have two possibilities: (i) bag in big bags and make land transport in common trucks of general cargo ii) to make de land transport in hopper trucks. Land transport distance is 1,300 km
In your experience, what would be the best technical-economic option?
thank you
Daniel ■
Re: Looking For Power And Effort Calculation Manual For Steep A…
Dear dandaniel,
You are referring to a logistic choice to make.
-The soda ash is transported by incoming (sea)ships to the port.
-The soda ash must be transported inland over 1300 km.
When the transport overland is done in big bags you must have a bulk bag filling facility.
This big bag filling facility must keep up with the ship unloading rate or an intermediate storage must be available. (most likely required anyway)
The option to use pneumatic silo trucks is also an option.
Then you need a bulk truck loading station and a surge hopper for loading the pneumatic bulk trucks
Depending of the overland transport capacity, the required number of common trucks versus the required number of pneumatic bulk trucks must be assessed.
Based on the availability of the estimated number of common trucks and the availability of pneumatic bulk trucks on the market must be weighed.
Or the decision to order your own fleet of trucks (common or pneumatic)
At the receiving site, the unloading of big bags or pneumatic road tankers must be assessed including the labor requirement.
Dust problems with big bag handling must be solved.
The annual tonnage must be accounted for in your assessment.
All assuming that the soda ash is in a form that it can be moved pneumatically.
You have not mentioned how the sea ship is unloaded. (by grab, screw unloader or pneumatic unloader)
lithium carbonate is used for the production if a medicine.
The amount of soda ash is probably very low on a yearly basis, which could result in a preference for big bags. ■
Teus
Looking for Power and effort calculation manual for Steep Angle Conveyor / sidewall
Hello everyone, i'm looking for power and effort calculation manual for Steep Angle Conveyor / sidewall
I hope to be in the correct group otherwise please indicate to me which is the most suitable group
Where can I find a manual with the formulas for the calculation of the power and strain for "Z" shaped belt conveyors? ■