Novel Thimble Press

VHE has designed and fabricated a thimble removal press with several novel features. The machine was installed in a smelter in Iceland in mid-2013.

The thimble press is designed for use with stubs arranged three in line but may be adapted for other configurations. Uniquely, the design permits the machine to automatically adjust to yokes with different stem offsets, a necessary feature at certain smelters.

When a rod enters the press the stem is clamped with a set of hydraulically operated rollers which permit the secured rod to move vertically during the thimble removal process. Three pairs of hydraulically operated clamps close around the stubs immediately above the thimbles. These clamps have adequate tolerance to accommodate bent stubs.

A single 500 mm bore hydraulic cylinder provides the breaking force, moving an anvil head upwards to engage the bottoms of all three thimbles and forcing them against the three pairs of stub clamps, breaking the thimbles. The thimble pieces fall in chutes on either side of the machine from where they are delivered to a discharge conveyor for further processing.

A state-of-the-art hydraulic power pack ensures that adequate pressure and flow is maintained at all times, through the use of two 75 kW motors driving variable displacement pumps.

Velaverkstaedi Hjalta Einarssonar - VHE is a major mechanical fabricator, offering a comprehensive range of design, manufacturing and site services. VHE now provides all Stimir solutions to the primary aluminium industry, with particular focus on the Rodding Plant. All aspects of design and fabrication are undertaken at VHE’s own facilities, ensuring total quality control and on-time delivery.

Photograph – VHE Thimble Press – during fabrication at VHE

Photograph – VHE Thimble Press – graphic

Based on VHE information