CEMEX Angerstein back into full production with a ‘new design’ CMB Aggregate Screen.

Owned and operated by CEMEX UK the operation at Angerstein Wharf is a one of the largest operations within the company, supplying London with over a million tonnes of aggregates per annum.

The original plant which incorporates Cedarapids screens from the USA was installed in 2006 and the screens have been troublesome since the initial installation which required intermittent welding due to frame failure. This meant that to order a new screen from the USA meant a ten week lead time. With such an intensive operation it was vital to find a solution to the problem and in due course CMB International (who have successfully installed screens at Northfleet and other CEMEX operations) were called in to look at the issues and provide a solution.

24/7 operation:
Working on a two shift, 24/7 operation with truck loading done around the clock it is imperative that the production is continuous. With a small 5 acre footprint stockpiles are around 5000 tonnes with a daily production the same. With a 24/7 two shift system this facilitates the despatch of up to 5000 tonnes into London daily.

The solution:
After a site visit and a thorough inspection CMB sat down with David Whitby to discuss a solution. As Angerstein shared a ‘spare screen’ with Northfleet it was imperative that this be maintained in the most efficient way possible. This however had been a problem in the past as Angerstein is a twin production line and the screens are ‘handed’ left and right.
Martin Brough – Director of CMB International, commented, “Apart from a better designed screen replacement it was obvious that if we designed another screen which could be handed either side then only one stand-by would be required as this would fit either Angerstein or the CEMEX operation at Northfleet.”

Therefore not only did CMB supply a new replacement of a new design for the screen frame they also resolved the configuration problem with the supply of a brand new ‘unhanded’ spare screen at the same time. The new replacement screen features a complete new live frame including side plates and incorporates an extra-long ‘doubler’ plate, decks, feed boot and discharge lips. Any parts of the vibrator unit that were in good condition were reused with all other parts replaced. Like the screen at Northfleet the amount of G-force being applied to the new screen was reduced whilst it was running to help prolong the life of the decks and the side plates.

Unit Manager - David Whitby, commented, “Now CMB have manufactured us a new spare screen with the drive system sitting on top it no longer matters where the screen is required, either here or at Northfleet as we share the ‘spare’. This has not only made replacing a screen more efficient but is also a huge cost saving by not having to swap the configuration. This has now eliminated any ongoing issues and also consolidated the amount of spares that Angerstein and Northfleet require. So we will have one spare screen ready for either operation which can be quickly exchanged at either site in the case of failure with the faulty screen being repaired and then put back into ‘standby’; it’s perfect! Any total screen failure now means two days before back up in full operation, whereas previously it was a week plus downtime.”

“The new design screen installation by CMB has resolved so many long standing issues and since commissioning it has performed with no problems whatsoever. We are very happy as not only do we have a dual spare, we are now completely self-sufficient as we haven’t had to import any material to satisfy our demand when we had extensive downtime.”