Giving Archimedes A Little Help In The 21st Century

The Archimedes screw – a cylinder containing a continuous screw extending its length to form a spiral chamber – is believed to have been invented by Archimedes in 287 BC and was one of the earlier types of pump which today can be used in a variety of industries.

A Hughes & Son, from Skellingthorpe, in Lincs., which renders animal and food waste products into tallow (fat) and bone-meal, needed to change the design of the company’s Archimedes screw to make it work more efficiently. They contacted Croft in the hope that they would be able to improve their screw’s existing design because their current Archimedes screw assembly had a filter at the top of the unit which was struggling to fulfil its purpose.

Croft’s experts devised an ingenious solution which was relatively simple to manufacture by creating a screw assembly where the slots ran lengthways instead of widthways. This was then fitted with a wedge wire trough, designed to an exacting specification, which enabled the trough to drain animal fat – at temperatures up to 130C.As a result of the modification the screw moves more smoothly as it passes over the trough and squeezes the fat out more efficiently. Work was done by Croft’s wedge wire division. The trough was delivered to the customer in November at a cost of only £1,200.

Neil Burns, partner, commented that this was just the sort of challenge the Croft team like to take on.He said: “A customer has a problem and our challenge is to find a cost-effective way of solving that problem.”