Electromagnetic Casting Pump & Furnace Compatibility for Aluminum Foundries
Electromagnetic (EM) pumps are a form of casting automation that solve many of the most common challenges aluminum foundries face. EM pumps are placed inside furnaces and use electromagnetism – not moving parts – to move precise amounts of molten metal from furnace to casting. In doing so, EM pumps produce excellent consistency from pour to pour.
By automating casting, EM pumps make foundries safer and more efficient: they move workers away from molten metal (and therefore alleviate staffing struggles), improve metal quality by reducing turbulent flow, and help foundries maximize yield. For any foundry interested in automating operations, EM pumps – or another form of casting automation – are an integral piece of the puzzle.
EM pumps may be used in a variety of applications, including low pressure bottom fill, low pressure side fill and gravity pour. But, while the pumps are highly versatile, they aren’t compatible with all furnace types. Here’s what you need to know about which furnaces are (and aren’t) compatible with EM pumps.
Sizing (& Other) Specifications
CMI Novacast manufactures two EM pump models for aluminum foundries: the PG 300 and PG 450. The PG 300 is a compact pump best suited to gravity pour applications and has a typical molding rate of up to 180 castings per hour. The PG 450 is a larger pump best suited to low-pressure bottom fill applications and has a typical molding rate of 200 castings per hour. The specifications for each pump are outlined below:
PG 450
PG 300
Incompatible Furnaces
The furnaces below are incompatible with both the PG 300 and PG 450.
Induction Furnaces
Induction furnaces use electricity to quickly melt metal. Because induction furnaces and EM pumps operate off the same principal and are both powered by induction, they cannot be used together. Because an induction furnace’s circuit is much larger than an EM pump’s, the induction furnace essentially overrides the pump, causing it to malfunction.
Crucible Furnaces Under 2,000 Lbs.
Crucible furnaces are basic tools used to melt and hold metal. The majority of crucible furnaces are naturally incompatible with EM pumps because they are simply too small. Even if an EM pump can fit inside the well, most crucible furnaces still generally won’t be spacious enough to maintain the metal level needed to make the pump worthwhile. Every casting draws down the metal level in the furnace, which can significantly alter the performance of the pump. Further, using an EM pump with a furnace that’s too small can result in a highly inefficient casting process: if the pump consumes a majority of the metal in the furnace to complete a small number of castings, new metal will constantly need to be fed to the furnace.
Occasionally Compatible Furnaces
The furnaces below may sometimes be compatible with the PG 300 and PG 450.
Certain Crucible Furnaces Over 2,000 Lbs.
Crucible furnaces that are large enough to fit an EM pump are rare but do exist. For a crucible furnace to work with an EM pump, it must be large enough both to fit the pump and maintain a level of metal that allows the pump to complete a reasonable number of castings before the furnace needs to be refilled. Generally, when EM pumps are used with crucible furnaces, the crucible acts as a holding furnace and is charged by another melting furnace.
Modified Pressurized Furnaces
Pressurized furnaces are sealed systems that use hot gas to exert pressure on molten metal and force it up through stalks into a mold. Because pressurized furnaces use gas to move metal, they do not require an EM pump – or any other casting process – to fill molds. That said, if you have a pressurized furnace and are interested in using an EM pump, modifications may be made to the furnace to make it compatible with the pump. For example, the heating portion and lining of the furnace may be repurposed and the lid may be altered to create a semi-sealed system. The resulting furnace – which will no longer be pressurized – can accommodate an EM pump.
Compatible Furnaces
The furnaces below are always compatible with the PG 300 and PG 450.
Stack Melters
Stack melters are automated, highly efficient, multi-chamber systems. Generally, metal is preheated in an exhaust stack by hot gas, melted at the bottom of the stack and, ultimately, flows down to a heated holding chamber. The majority of stack melters have large baths, which can comfortably fit an EM pump. Further, stack melters have an excellent melt rate and are capable of maintaining a high and consistent level of metal – which is ideal for an EM pump.
Reverberatory Furnaces
Reverberatory (or “reverb”) furnaces use indirect source of heat, like a fire box or burner, to melt metal. Most reverb furnaces have large baths and can melt metal relatively quickly, which makes them a good candidate to host an EM pump.
Automate Casting with CMI Novacast
Since its founding in 1981, CMI Novacast has supplied foundries with EM pumps and related systems, including heated launders, preheat ovens and control systems, to alleviate common casting problems. Contact a CMI Novacast factory expert to learn more about furnace compatibility or to see how electromagnetic pumps can automate your casting process.
