Induction furnace with unique carbon foam insulation
View Patent ↗An insulative cap for an induction furnace comprising a carbon foam having a pore distribution such that at least about 90% of the pore volume of the pores have a diameter of between about 10 and about 150 microns and at least about 1% of the pores have a diameter of between about 0.8 and about 3.5 microns.
1. An insulative plug for a furnace, comprising a plug having an outwardly extending peripheral flange and formed of a carbon foam having a pore distribution such that at least about 90% of the pore volume of the pores have a diameter of between about 10 and about 150 microns and at least about 1% of the pore volume of the pores have a diameter of between about 0.8 and about 3.5 microns.
2. The plug of claim 1 wherein at least about 95% of the pore volume of the pores have a diameter of between about 25 and about 95 microns.
3. The plug of claim 2 wherein from about 2% to about 10% of the pore volume of the pores have a diameter of about 1 to about 2 microns.
4. The plug of claim 1 wherein the carbon foam has a ratio of compressive strength to density of at least about 7000 psi/g/cc.
5. The plug of claim 4 wherein the carbon foam has a ratio of compressive strength to density of at least about 8000 psi/g/cc.
6. The plug of claim 5 wherein the carbon foam has a density of from about 0.05 to about 0.4 and a compressive strength of at least about 2000 psi.
7. The plug of claim 6 wherein the carbon foam has a porosity of between about 65% and about 95% .
8. The plug of claim 7 wherein the pores of the carbon foam have, on average, an aspect ratio of between about 1.0 and about 1.5.
9. The plug of claim 1 which has a permeability of no greater than about 3.0 darcys.