Algorithm for Burden Calculation for Foundry Furnaces Using Charge Materials with an Uncertain Composition

Abstract

Calculation of charge burden to foundry furnaces by computing the proportions of particular charge materials is a most complicated task as a variety of technological aspects have to be considered. For practical and economic reasons, this problem is typically solved using computer-based optimisation methods, the main criterion being the optimal amount of charge materials related to the lowest costs of the burden. The problem is further complicated when the chemical composition of the charge materials is not accurately defined. So far the calculations of the charge burden were performed in order to work out the detailed melt procedure, which was to be modified and corrected by the trial and error method in subsequent melt processes.An algorithm has been developed for use in calculating the charge burden depending on the target chemical composition of the casting alloy. Of particular importance is the application of the algorithm when the process conditions are changeable.Keywords: burden calculation, melting optimization, control weighting of charge materials Wyznaczanie namiaru wsadu do pieców odlewniczych, metodą obliczeń udziału poszczególnych materiałów wsadowych jest zadaniem złożonym z powodu znacznej liczby założeń technologicznych. Ze względów merytorycznych, praktycznych i ekonomicznych dąży się takiego zadania za pomocą komputerowych metod optymalizacyjnych, w których uwzględnia się kryterium optymalnej ilości materiałów przy najniższym koszcie całkowitym namiaru. Problem złożoności zadań jest tym większy im bardziej skład chemiczny materiałów wsadowych jest nieprecyzyjny. Dotychczas obliczanie namiaru wsadu było zazwyczaj realizowane wyłącznie na potrzeby przygotowania instrukcji wytopu, którą korygowano wynikami uzyskanymi metodą prób i błędów w kolejnych wytopach.W artykule przedstawiono algorytm wyznaczania namiaru wsadu zestawianego w sposób zależny od zapotrzebowania na określony skład chemiczny produkowanego stopu odlewniczego. Szczególną uwagę zwrócono na możliwość efektywnego działania algorytmu w zmiennych warunkach technologicznych.

Multi-Stage optimization under uncertainty in reverse logistics operations: An industrial scenario

“…There are some methods which can be adopted to reduce the cost like bulk purchasing of the materials, hedging of raw materials cost, and reuse of the returns/ rejects in the charge mix. Ziółkowski (2013) shows that the effort of optimising the cost of manufacturing the casting alloys generates different processes to determine the charging burden required for the casting depending on the properties of the casting alloys. The application of linear programming for the optimization of charge mixing in foundry operation is common.…”

An IT System for the Remote Burden Optimization of Foundry Furnaces

“…Determining the optimal burden of an assumed chemical composition requires the formulation of an optimization task by defining an objective function (usually minimum charge cost) and a constraints system. Various mathematical models of such an optimization task have been described in publications including [1][2][3][4]. To solve such tasks, the following can be used:…”

Iterative Standard Strategy for Non-Linear Optimization in Melting Furnace Charge Calculations

“…Li et al [6] developed a model to investigate the kinetics of melting of solid scrap in the liquid metal. Ziółkowski [7,8] has addressed the uncertainties in chemical compositions and proposed a fuzzy optimization model to solve the issue. Omole and Raymond [9] studied carbon and silicon loss in a rotary furnace for cast iron melting, aiming to minimize the loss and to keep the alloy in the range.…”