CASE STUDY: LITOSTROJ

The casting box concept for handmade casting in the actual field of practice

Ein mit ECOFORM hergestelltes Francis-Blatt

A Francis blade produced with ECOFORM

New technologies can only gain widespread acceptance if it possible for them to reproduce results, they have been tried and proven in actual practice and they offer economic advantages for their users. We would like to tell you here about the advantages of ECOFORM by taking the example of a part constructed with it. The cast part is a Kaplan blade, which is used in the energy sector. It is manufactured in Slovenia by the company Litostroj, which we would like to expressly thank for allowing us to use its information and documents.

Process cycle

The Litostroj foundry has a partially automated hand mould line from G U T GmbH and successfully uses ECOFORM. The process takes place in the following steps:

The two-part ECOFORM halves of the box are placed on the model and the upper part of the box upon which the moulding box bars are located is lifted.
After this, the casting box is filled with contact sand and the upper box is placed on it once again, with the moulding box bar being run into the contact sand.
The filling sand is then introduced in the next step.

In addition to stabilising the mould through the positioning of the moulding box bar near the cast part, the heat is removed in an optimised manner via the moulding box bar and boxes. This results not only in a considerable reduction in the filling sand required – it also allows a significant shortening of the cooling period. In the conventional mould concept, on the other hand, the thicker layer of filling sand acts as an insulator and it takes much longer for the heat to be channelled off. This results in much longer cooling times and requires considerably more valuable production space.

A Francis blade produced with ECOFORM

The two ECOFORM mould halves are transported through the moulding line and then separated from the model with a pin-lifting device.
After preliminary drying of the mould in the furnace, the mould is slurried and then dried. Load-turning devices are used to ensure secure handling. These can also be used to put the mould together.
After the halves of the mould are placed together, the casting process is carried out, followed by the cooling – with significantly shorter cooling times.

Cooling times

Cooling times were reduced by up to 75% in the manufacture of the Kaplan blades described above.

The cooling times in the manufacturing process for a Kaplan blade are shown here.
The ECOFORM mould system is compared here with standard pit moulding.

We would like to thank Litostroj Steel Ltd.
(Slovenia) for its friendly technical support
and for releasing and making available the
illustrations and technical data.

ECO-FORM ein Geschäftsbereich der G U T Giesserei Umwelt Technik GmbH
www.gut-gmbh.de