Details
Dosing Furnaces
Dosing furnaces hold aluminium or magnesium alloys within a defined temperature range and transfer a specified quantity of molten metal to a die casting machine, gravity casting machine or another casting process. Holding, dosing movement and the machine cycle are therefore combined into one coordinated production system.
A dosing furnace performs three connected duties
The system must keep the molten metal in a suitable condition, form the requested quantity and transfer it to the casting system within the available time window.
Two fundamental application areas
Aluminium and magnesium dosing furnaces may appear similar from the outside, but they differ considerably in metal handling, protective systems, dosing equipment and operation.
Aluminium dosing furnaces are frequently designed as gas-tight, electrically heated holding and dosing systems. Pressurisation raises the metal level inside the riser tube and guides the specified quantity of molten metal to the casting machine.
Magnesium holding and dosing furnaces use metal vessels, dosing equipment and protective systems designed specifically for the alloy. Depending on the design, the metal may be conveyed by a pump submerged in the molten bath.
Dosing aluminium through pressure and a riser tube
With the pneumatic dosing principle, the closed furnace chamber is pressurised in a controlled manner. This raises the molten metal through the riser tube and transfers it along the defined metal path to the casting system.
Dosing equipment for magnesium
Depending on their design, magnesium dosing systems can use different pump principles. Delivery rate and dosing weight are not the only decisive factors. Resistance to temperature changes, contamination behaviour, the protective system and maintenance access must also be considered.
The dosing weight must remain within a stable process window
The target value alone is not sufficient. Repeatability results from the interaction between metal temperature, bath level, pressure curve or pump movement, dosing time and the condition of the metal path.
Which technical data determine suitability?
The manufacturer, model and year of manufacture provide initial guidance. For a reliable technical assignment of a used dosing furnace, however, the metal, capacity, dosing equipment, performance, interfaces and actual scope of supply are decisive.
The PLC connects the dosing parameters with the machine cycle
Modern dosing furnaces can store different parameter sets for different dies or casting weights. This requires clearly defined communication between the furnace, casting machine and, where applicable, the higher-level production control system.
Used dosing furnaces from various manufacturers
The available equipment may include aluminium dosing furnaces, magnesium holding and dosing systems and associated cover-gas, preheating and control equipment. The data in the individual machine listing are authoritative.
Technical inspection of a used dosing furnace
A reliable condition assessment covers the furnace body, refractory lining, heating equipment, dosing equipment, metal handling, control system, safety equipment and all auxiliary units required for operation.
Reuse begins with documenting the interfaces
A used dosing furnace may be technically functional and still be unsuitable for the new casting cell. The transfer height, metal demand, control system, energy supply and safety concept should therefore be checked before dismantling and transport.
Additional furnace equipment for metal supply and foundries
Dosing furnaces are frequently part of a complete metal supply system. Depending on the production concept, additional melting, holding, recycling and transfer equipment may be required.
FISS supports the search for a suitable aluminium or magnesium dosing furnace and its technical assignment based on the alloy, holding capacity, dosing weight, delivery rate, temperature range, heating system, metal path, dosing equipment, control system and existing casting machine. If no suitable furnace is currently listed, FISS can conduct a targeted search through its international network for an appropriate solution.
When selling equipment, FISS supports condition assessment, technical documentation, dismantling planning and international marketing of individual dosing furnaces and complete metal-supply and foundry systems. In addition to brokerage and international marketing, direct purchase by FISS may also be an option depending on the project.
