As the designer only you can decide how the conveyor / its winch(s?) will operate.

Assuming you have decided to keep the winch "active" while stopping the conveyor [including, I assume, during power failure events etc], I understand that in AU others have developed a suitably [for their application] "fast" acting fail safe hydraulic winch for a similar duty.

Obviously I am not aware of your situation, though personally I would exhaust most other options prior to considering such an arrangement.

Edit:

These may be of interest:

https://forum.bulk-online.com/archiv...p/t-24499.html

http://www.saimh.co.za/beltcon/beltcon7/paper710.html

http://www.saimh.co.za/beltcon/beltcon8/paper83.html

Regards,

Lyle ■

There was an exciting thread a few weeks back on this very subject.

If you can trace it you will find more than you bargained for. Arguments were long and repetitive but the proponent of winches, from Johannesburg, Saath Efrika, mentioned that he had software to remedy situations like yours. Have a word there.

I'm not going to find it for you, thrill of the chase and all that.

Good hunting. ■

Dear Zhu John,

This is a typical underground trunk belt used in the coal industry. The first step is that you have to sequence your motors correctly with the tripper drive acting as a slave to the primary drive. You also need a tension feed back system so that your winch and drive can anticipate what is happening by ensuring that there is never a lack of face pressure on any of the drive pulleys. You cannot achieve this unless you have some feedback system at the tripper drive. It is also extremely important you start the system slowly to allow the stretch in the belt to be taken up without creating any form of tension wave. To do this you need to model the whole system and this requires detail of the system inclusive of profile and tonnages. This design of these systems is common place in underground coal mines in Australia. As far as the winch speed is concerned you do require a fast retrieval system, easiest with hydraulics or VVVF, issues if you are using a eddy current drive as they have a delay in any reaction that can be fatal.

You have quite a bit of research to do as John points out but there are also a lot of papers about on designing and setting up tripper drives successfully

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.com ■

For attention Zhu John

Firstly thanks to John Gateley for his recommendation.

My company has specialized in Conveyor Tension Control for 33 years and we have supplied some 700 systems mostly in South Africa but also around the world. We develop, design and manufacture our Fixed Speed and Variable Speed Conveyor Tension Controllers as well as our own 2-Wire True Loop-Powered Tension Transducers.

Take-Up Winches are certainly suitable for all any any type of belt. Designed correctly, a Take-Up Winch will outperform any Gravity Tower system. For the winch to be able to pay out fast enough following loss of power you must either have a faster winch and/or a slip clutch on the winch.

Your problem with payout speed of a winch is a common one. Loss of power especially during belt acceleration is a worst case scenario. Most conveyors designers choose Fixed-Speed Take-Up Winches to cope with acceleration and normal running. However this is always a compromise between handling the start-up and handling normal running. Only a Variable Speed Take-Up Winch can properly meet the requirement. Our EGT-28AX Universal Tension Controller can handle any size of Winch on any size of conveyor. It will control the belt tension with PID (Proportional, Integral, Derivative), it can also function as a multiple tension controller, e.g. for damping tension transients on long conveyors with Gravity Tower tensioning.

Variable Speed Take-Up Winches are far better able to handle excessive Tension Transients than Fixed-Speed Winches. If you must use a Fixed Speed Winch then you have to have a release mechanism.

One of our distributors in South Africa, Dymot Engineering, manufactures Take-up Winches and they have two methods of handling excessive Tension Transients. One is a Slip Clutch added on to the side of the winch, the other is an hydraulic dissipator which is still under development. With the Slip Clutch, you can get by with a slower winch. With a Variable Speed Winch and a Slip Clutch you have the best of both worlds.

Can we help?

Ian Plunkett

Iptron Technology cc ■