A recorded talk that explains why large induction furnace linings crack and how a segmented system answers it.
A recorded presentation for foundry and melt shop engineers.
It turns the finite element study behind InterLok into a lining you can install.
The InterLok white paper presentation explains why medium and large coreless induction furnace linings crack, spall and erode, and how a segmented lining reduces the cause. InterLok replaces a rammed or mortared lining with dense, fully fired tongue and groove segments that are set without mortar, backed by a rammed refractory and held down by a spring loaded plate, so the lining can expand and contract through every heat and cool down.
| Item | Detail |
|---|---|
| Format | Recorded video presentation |
| Presenter | Phil Geers, Senior Market Manager Molten Metals, Blasch Precision Ceramics |
| Based on | Blasch white paper on thermal stresses in large induction furnace refractory linings (P. Geers, W. Russell, 2016) |
In a coreless induction furnace the metal heats from the inside while the water cooled coil keeps the outer face of the lining cold. Medium and large linings carry that gradient over a big diameter and height, and they show four recurring failures: thermal expansion, cracking, corrosion and erosion.
A rammed or mortared lining behaves as one body. It cracks until the cracks have divided it into pieces, and metal that runs into the cracks on cooling opens them further on the next heat.
The segments are cast to shape and fired before delivery. Their tongue and groove joints carry designed expansion gaps, so each segment takes up its own growth and the gaps close at operating temperature.
The lining is sold as a complete system: segments, a matched backup ram, a slip plane, a plastic refractory topping, the spout and a metal hold down plate connected to a spring pack in the furnace.
Options include pour spouts cast into the lining, custom geometry and bottom pour openings, for vacuum, air melt and atomizing furnaces.
The InterLok product sheet lists eleven standard sizes for melts from 650 lb (295 kg) to 15,000 lb (6,804 kg) of steel. Height can be adapted through the brick height or the number of courses.
The presentation does not ask for a stronger ceramic first: it asks for a lining that is already divided where it would otherwise crack.
If your lining fails by cracks that fill with metal, by spalling of aggressive alloys or by long rebuilds between campaigns, the presentation gives you the reasoning to compare a segmented lining with your current rammed or brick construction. Installation and tear out follow the same steps every time because the system is modular, which makes lining changes easier to plan.
The stress analysis itself is summarized on the page for the white paper on thermal stresses. The InterLok installation animation shows the install sequence step by step, and the InterLok product page lists sizes and options.
For other melt shop parts, from crucibles to sample cups, see the crucible and melt products range and the molten metals overview.
Melt shop, foundry and maintenance engineers who run medium or large coreless induction furnaces in air or vacuum, including investment casting and atomizing lines.
No. The segments form the hot face. A backup ram is rammed behind and below them and is specified together with the lining.
The segments handle horizontal stress, but the lining still grows in height. The spring loaded plate keeps the assembly together while it moves through each heat.
Yes. Bottom pour openings and cast in spouts with extensions are available options of the system.
Send the furnace capacity, the alloys you melt and how the current lining fails. A Blasch engineer works out the segment layout and the backup ram.
