Key takeaways
- UHE, Ultra High Efficiency, wraps the coil in a continuous crown of magnetic laminations and a stainless-steel shell, sized for the lowest stray field and the lowest energy per tonne.
- UHP, Ultra High Power, clamps the coil with magnetic plates, giving an exceptionally robust structure that holds steady at extreme power.
- The UHE structure stands out for supporting efficiency, the UHP structure for supporting high power. On either structure the coil is modular: individual bolted bridge-type copper turns, monitored and interchangeable, which can be bypassed when needed so production continues. CIME builds coreless melting furnaces up to 10 MW.
Two ways to build the same furnace
The coils are built the same way in both designs. In a coreless furnace the water-cooled coils carry the alternating current that melts the charge. What changes between UHE and UHP is the magnetic structure wrapped around those coils: the assembly that closes the magnetic field and holds everything together.
UHE, Ultra High Efficiency, wraps the coils in a continuous crown of magnetic laminations, covered by a stainless-steel outer shell and sized to keep the stray magnetic field as low as possible. The result is a solid structure that does not vibrate, with high insulation efficiency and the lowest energy per tonne.
Note
The saving from UHE is not a fixed catalogue figure. It depends on the metal, the furnace size and the duty cycle, and it is measured on the actual production line, in kWh per tonne.
UHP, Ultra High Power, is designed with water-cooled magnetic plates that surround the coil and clamp it by means of pushers, keeping it compact and compressed. This clamping gives an exceptionally robust assembly that holds steady even at extreme power, with zero vibration.
Both builds are efficient and both insulate well: the difference is whether the design is optimised for higher or lower power.
UHE vs. UHP, head to head
The choice is not better against worse. It is which goal matters most on a given line: the lowest kilowatt-hours per tonne, or the most robust structure at extreme power. Maximum furnace power is 10 MW in either build.
Both structures sit underneath the same coreless melting range. For the underlying physics, see how an induction furnace works.
The choice is not about what is better or worse. The choice depends on the foundry's production, in particular on the tonnes per hour required.
CIME Technical Office, Turin
The modular coil
On top of either structure, the coil itself is modular. It is built from individually bolted, interchangeable bridge sections, and each turn carries its own cooling, its own temperature reading and its own on-screen monitoring. The operator sees the state of every turn in real time, not just the furnace as a whole.
If a single turn shows an anomaly, that section is isolated and bypassed so the furnace keeps running without interrupting production. In this way only the damaged turn needs to be replaced, not the whole coil.
Key point
UHE and UHP are two ways of designing the structure of our furnaces. Tell us the metal and the duty cycle, and the right magnetic structure follows, with a modular coil on either one.
Frequently asked questions
What is the difference between UHE and UHP?
They are two ways of building the magnetic structure around the same coil. UHE, Ultra High Efficiency, wraps the coils in a continuous crown of magnetic laminations for the lowest energy per tonne. UHP, Ultra High Power, clamps the coils with magnetic plates for an exceptionally robust structure that sustains extreme power. Both reduce energy use and both are designed to keep vibration to a minimum.
Is UHE really more efficient?
UHE is the build designed for the lowest energy per tonne: the continuous crown of laminations keeps the stray magnetic field low. How much it actually saves depends on the metal, the furnace size and the duty cycle of the line, so any comparison has to be made case by case.
What does a modular coil add to either build?
The modular coil is made of bolted, interchangeable bridge sections, each with its own cooling, temperature reading and on-screen monitoring. If a turn shows an anomaly, that section is isolated and bypassed so the furnace keeps running, and only the damaged section is later replaced.
References and sources
- CIME S.r.l., internal melting-furnace design documentation, Turin (UHE and UHP coil structures, modular coil).
- Foundry Trade Journal, technical article on coreless induction practice, 2006.
- Cast Metal Times, coreless induction melting and coil design, 2004.