Modern slag management needs weighing data
Wheel loaders at Thyssen Krupp Mill Services & Systems use mobile weighing technology|
Thyssen Krupp Mill Services & Systems, in the HKM-Stahlwerk Duisburg-Huckingen, moves about two million tons of steelwork slag. The slag is a highly valued raw material especially for the building of roads and paths. To capture material flows, the Thyssen-Krupp subsidiary uses a modern slag management system based, among other, on the weighing results of about 25 Pfreundt wheel loaders moving about on the site. They are equipped with mobile Pfreundt weighing systems and the weight data are transmitted to a central control point by GSM.
The Hüttenwerke Krupp-Mannesmann GmbH (HKM) in Huckingen has a capacity of 5.6 million tons per year and produces slabs and round sections in 1 500 steel grades, exclusively for its three shareholders Thyssen Krupp Steel AG, Salzgitter Mannesmann GmbH und Vallourec Mannesmann Tubes S.A.
A much valued raw material for the building industry
About 2 million tons of steelwork and blast furnace slag are generated, appreciated especially as building material for road construction. The company operating the steelworks is marketing the slag. HKM has delegated the entire handling, however: Thyssen Krupp Mill Services & Systems is responsible for transporting the different types of slag and for storing and processing the slag into standardised products. The service companies in the steel sector were recently bundled under this name by Thyssen Krupp.
The service provider is established in Huckingen, boasting modern processing plants and a large pool of trucks and mobile machinery to collect the slag at its point of origin, to store it and to produce a raw material from this “by-product” by separating out the metallic components, by breaking, classifying and mixing until HKM then sells the material locally and abroad. In this way they are not only saving dumping space but also resources.
Complex processes - and large quantities
The individual processing steps may appear obvious to the layman, but the material flows managed by Thyssen Krupp Mill Services & Systems on the large Huckingen site are quite complex. The issue gets even more complex when the customer side, i.e. the exchange of information with HKM, is included in the equation. Because HKM sends a message to the service provider to the effect that a customer has ordered a certain slag quality and quantity and when it will be collected. This includes several transports a day: If you divide two million tons by 365 days, the answer is 5 500 tons per day.
Wheel loaders assume key functions
One of Thyssen Krupp Mill Services & System’s responsibilities is to have the ordered quantities available and to load the trucks with the corresponding product quality. This is generally taken care of by wheel loaders, of which about 30 are in action. The majority of these – currently 25 – are equipped with a Pfreundt mobile wheel loader scale. The Südlohn manufacturer’s service department generally fits such a scale into a newly acquired wheel loader directly on site.
The scale has the task of optimally utilising the maximum permissible total weight of the truck, but never to allow it to be exceeded. This is where the totalling function of the WK 50 weighing electronics provides the answer – and you save time because the machines do not need to make the detour via a stationary scale.
Modern slag management with mobile weighing technology
But a second task, performed by the scales, is almost more important. Dipl.-Ing. Andreas Rollfinke, Plant manager, Processing at Thyssen Krupp Mill Services & Systems in Huckingen says: “The weighing data are part of a modern slag management system that we are presently developing.” The scales furthermore serve to record the total quantities handled at the different storage places on the expansive steelwork site and transported to the individual processing stages. Thyssen Krupp uses the scale manufacturer‘s GSM module for data transfer, obviating the use of physical data carriers. The data are transmitted to central control, wireless and automatically.
The WK 50 evaluates displays and passes on the weighing data via GSM module - it is fitted in the driver’s cabin. The driver enters his current order number on the robust console. The large, clearly legible display shows him the content of each bucket (the wheel loaders are capable of moving up to 12 tons of slag with each operation) as well as the total quantity that is, for instance, loaded onto a truck or with which a processing plant is charged.
According to Thyssen Krupp, the robustness of the WK 50 systems is a significant advantage: Even under very rough environmental conditions, the weighing sensor system and electronics excel in their durability and virtually trouble-free operation. Andreas Rollfinke: “And should there be a problem or malfunction, Pfreundt’s Service team is on site in no time.”
The 10 000th WK 50 is in operation in Huckingen
At the beginning of the year, the customer service manager and Pfreundt sales management arrived on site for a special appointment: Thyssen Krupp Mill Services & Systems had ordered a weighing system for a new wheel loader and theirs was the WK 50 serial number “10 000”. 25 wheel loaders with WK 50 weighing electronics are herewith an integral part of slag management in Hucklingen.
Including the predecessor models of the WK 50s, about 20 000 mobile Pfreundt weighing systems have even been installed worldwide over 30 years. Wheel loaders are primarily used in mining and disposal. Ever since the introduction of the WK 50 electronics, the scales are now also used in excavators, dumpers, conveyor belts, skip containers and various disposal vehicles. The applications using Pfreundt weighing technology even include “exotic” special vehicles such as surface miners in Chile and ingot transporters in South African iron ore mines.
Wheel loader tasks include loading trucks with ready-to-sell slag used, among other, in road and path construction.
The weighing electronics reliably record the weight of the bucket content. Via the totalling function trucks can, for instance, be loaded with the required mass of slag.
left to right: Dirk Fuchtmann, Pfreundt GmbH Sales manager, Dipl.-Ing. Andreas Rollfinke, Plant manager, Processing, at Thyssen Krupp Mill Services & Systems, Michael Kleijn, Head of Processing in the same company, Michael Buning, Pfreundt GmbH sales consultant.
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