Re: Brake Specification For Declined Conveyors
Dear Wibo,
Conveeyor Dynamics, Inc. (CDI) can help. The are a number of factors that must be determined such as:
1. Size of downhill conveyor - Length, drop, tonnage, speed, ....
2. Acceptance of "Fail-Safe" design ( spring applied- hydr. release)
3. Climatic conditions; environmental conditions (coal ignition, etc.)
4. Single, dual or triple brake pulleys includes redundant braking
5. Client preferences on manufacturers for continued servicing
6. Control of belt safety factor - requires special consideration of meeting need to limit belt tension forces to the tolerable limit when brake mechanical, instruments, or PLC control malfunctions
7. Brake disk is dimensionally set by the thermal rating of a minimum number of stops per hour at full load- 4 to 6.
8. Detail brake specification can be a 20 page document
9. High or low speed shaft mounting - most large downhill systems are low speed brakes which offer a higher degree of reliability due to their robust design. They are considerably more expensive. High speed brakes have to deal with heat dissapation and caliper pad gasification and disk thermal stress shock. THe details to consider are many.
10. Caliper-disk, air or hydraulic, band style, hydraulic retarder, hydraulic clutch,......
11. How to integrate starting and stopping control functions
CDI have been involved with the design, specification and commissioning of many downhill belt conveyors around the world.
Five of the larger systems include:
1. Los Pelabres, Chile 10,000 kW drives x 2; 5,000 kW drive x 1
2. Colluhuasi, Chile 8,000 kW drive
3. El Abra, Chile 7,500 kW drive
4. Quintette, Canada 2611 kW x 2
5. Kennecott Copper, USA 4500 kW x 2 (head & tail drives)
The selection of the brake system can be complex. CDI has designed more than one hundred brake systems for large belt conveyors. The design includes all types and methods of control.
We would be please to work with you on your braking system. CDI has a large client list for references. I submit my contact information below:
Lawrence Nordell
President
email: nordell@conveyor-dynamics.com
website: www.conveyor-dynamics.com
phone: USA 360-671-2200 ■
Dh Brake System
Dear Sir,
CDI is correct, however if you need some more info, please contact M/s. Metchem, Canada OR M/s.Abacuss Hydraulics, Canada & Siemens or SIBRE & Siemens, they may study the case and come out with suggesstions. ■
Re: Brake Specification For Declined Conveyors
Dear Surresh,
What significant conveyor braking systems have these referenced manufactureres worked on?
LKN ■
D/H Conv Brake
We are having a downhill conv of c/c approx 800 m and 14 deg declined with capacity of 1400 tph of limestone.
we hv used hydraulic thrustor brakes. One on gear box input shaft motor side an dother on the same extended shaft on other side from SIBRE Germany.
They are working absolutely fine and trouble free for last 10 yrs or so.No maintenance atall except oil checking from time to time. Even the liners are not changed.
This conv is driven by 3x 110 KW motors and at speed of 3.3 m/s.
This is for yr reference pl. ■
D/H Conv. Braking System
Helo Bhatnagar Sir,
Are you from ACC? If so, I am from NMDC, Hyd. Do you remember me?
If not, please forget. ■
Re: Brake Specification For Declined Conveyors
Hello Wibo..
To answer your question, you will have to calculate the total kinetic energy of your conveyor, which is all the I x Omega squareds plus all the half M x V squareds for the worst load case.
You can then calculate the retarding force to stop the conveyor for the distance you require it to stop in, as:
retarding force x stopping distance = total kinetic energy.
You must then calculate the overall regenerative or negative effective tension of the conveyor in steady state. Some of this force will be positive and available via the conveyors natural frictional resistance ( use low friction value though e.g. f=.012).
The brake must therefore supply a force equal to the retarding force plus the absolute value of the negative effective tension.
Having calculated the brake force select a brake.
I normally use low-speed disc brakes. For greater heat dissipation use larger disc with smaller force, but of course we need the facts to be able to optimise.
LSL Tekpro ■
Brake Specification For Declined Conveyors
Dear Wibo,
We have build some of the larger downhill conveyors, such as
-Los Pelabres, Chile , -Colluhuasi, Chile , -El Abra, Chile
and the overland system with brakes, -Kennecott Copper, USA. Send us your conveyor details and we will help you. ■
Dear Mr. Suresh
Ya , I am from ACC and I do remember you.
Hope you are doing fine. ■
Brake Specification For Down Hill Conveyor
Dear Mr. Wibo,
To answer you properly, I need lot of information.
But the following may help you.
1.Other than electrical brake use DISK type brake with three nos. sensor.
2.Provide in motor shaft if fluid coupling is not used.
3.Provide two brakes & design one is adequite to take of full torque.
Regards.
A.Banerjee ■
Brake specification for declined conveyors
Hi everybody!
Does somebody know how to select and how to specify a brake for a declined regenerative belt conveyor?
Should the brake be mounted on the motor shaft, on the pulley shaft or on the input reducer shaft. The reducer is shaft mounted type and the drive is located on the tail pulley.
And finally: what about the heat dissipation of the energy absorbed by the brake. How does it work? Is the brake specified as a function of the heat absorption?
Thank you!
Wibo ■