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The system, proven in the US, is known as the Liquimetrics Auto-pour and takes the form of an automatic, pressure pouring, induction-heated furnace with controlled compensation for metal level changes to maintain a constant pour-rate over the entire range of usable metal capacity. The result is claimed to be a completely automatic and safe, reliable technique of dispensing molten metal into moulds with a pouring accuracy better than ± 3%. This degree of accuracy can be maintained from high to low metal levels and the furnace can be refilled while pouring without interrupting production.

Three models are currently available, these having usable metal capacities of 1450, 2950 and 5200 kg iron. The poured shot size ranges vary from 3 to 225 kg, 3 to 340 kg and 5 to 450 kg and the pouring rates are adjustable to 22, 34 and 34 kg/sec respectively.

The input power for the three models; using a 380/440 V, 50 Hz supply, is 135 and 195 kVA and the nominal furnace holding power requirements are of the order of 75, 85 and 100 kW respectively.

Press tool lubrication

Problems in the manufacture of heat exchanger panels at the Preston factory of Baxi Heating Ltd. are reported to have been solved by Salford University's Industrial Centre. Baxi had carried out a value engineering exercise on the heat exchanger used in their Baxi Bermuda domestic unit, but found that the heat exchanger panels recommended by this exercise were failing in the early manufacturing trials. In addition, they were also involved in unnecessarily high materials and tooling costs because of high press loads and excessive tool wear.

Baxi recalled some experimental work associated with lubrication and metal forming at Salford University, so contacted the Industrial Centre, which confirmed that the problem was essentially one of lubricant breakdown.

Laboratory tests carried out at the Industrial Centre indicated that the application of hydrostatic lubrication techniques would solve the problem. The centre then designed and manufactured a tool to simulate the forming conditions in the component and a test programme was commissioned. Based upon the test results, the Centre manufactured a production tool and supervised its installation. At the same time the Centre modified the client's press to convert it to double-action operation so that Baxi reduced materials' and tooling costs and press operation times.

Firth Brown's Atlas Melting Shop

Electric melting and refining as two separate processes

A new electric-arc melting shop in-corporating advanced melting and refining techniques has now been in successful operation for some twelve months in the Atlas Works of Firth Brown Ltd., Sheffield.

This represented a £3 million development (in late 'sixties terms) intended to cater for the increasing demand for higher quality special steels by such industries as the aero-space, nuclear engineering, power generating and so forth.

One answer to the demand for consistent high quality is to further refine the product by re-melting either in vacuum or by the electroflux process. Firth Brown is well equipped with special melting facilities of this type which include a vacuum induction melting plant, and two electroflux and four vacuum arc remelting units. However, these facilities cannot meet the bulk tonnage requirements for alloy and special steels and, moreover, the remelting processes increase the cost of the. final product quite considerably.

An economical and effective way of producing high quality steels is by separating the melting and refining processes, which in conventional steel-making

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