Re: Using Multiple Grabs In Grab Unloaders
Rope fittings can be passed throught sheaves. However, generally, the sheaves need to be designed for passing attachements. Your original sheaves may not be suitable for the particular QRA. ■
Using Multiple Grabs In Grab Unloaders
Thanks for the response.
We had replaced the old rope sheaves, with flared sheaves suitable for passing of QRAs in both Main & auxiliary trolleys.
Regards ■
Re: Using Multiple Grabs In Grab Unloaders
The dual trolley system is typically used to allow the primary trolley to travel without having to adjust load height. If this is how your secondary trolley functions, then this can, theoretically, be replaced with electric control that allows the system to adjust the load height. However, this would be a major modification for an existing machine.
Better to review the detail of your QRA travel and stress cycles. What you are doing should be quite possible. I will be in Mumbai in October at the conference. Feel free to phone me at the time, if you are there also. We can then discuss further. ■
Using Multiple Grabs In Grab Unloaders
Dear all,
What are the types of QRAs (Quick Release Attachements) available?
I am looking for anything other than Pear Sockets and link arrgt.
Awaiting response from members. ■
Using Multiple Grabs in Grab Unloaders
Dear all,
Originally Unloader at our jetty, was designed for handling Iron Ore & Pellet only, subsequently we needed to handle the Coke also. Coke being a lighter materials, we procured Quick Release Attachment" for quick changing of the Grabs.
However, the system never worked in our case, as the rope was failing right at the end , where we fill molten lead. We procured the QRA's & the filling compound from the world leader from Netherlands.
On looking at the reasons, one of the reason we found that we have two trolleys in the Unloader i.e. Main & Auxiliary trolleys. The auxiliary trolley is for tensioning of the rope.
The QRA in Open/close ropes passes through both the trolleys. During passing the direction of bending reverses, this causes fatigue stress of ropes, hence the premature failure.
The failure occurs only in open/close ropes. The hold ropes remain allright.
I want to know from the members of this Forum what is their experience in this regard.
Has anybody got similar experience?
Isn't it possible to use multiple Grabs in case of having auxiliary trolleys in the Unloaders?
Regards ■