Patent ID: 7717286

Claim:
A cover for inhibiting the escape of particles produced by a thermite reaction within a chamber of a crucible having a closed bottom and a circumferential wall that extends upwardly from said bottom, the top of said wall surrounding an opening into said chamber, said cover comprising a filter having a central opening, an inner face, a top face, a bottom face, and an outer face, and said filter bottom face being seatable atop said crucible wall with said filter opening in registration with said opening into said chamber, said filter passing gases but substantially blocking solid particles developed in said thermite reaction, and a lid having a downward facing circumferential flange mountable on said top face of said filter for sealing said chamber to inhibit the escape of particles produced by said thermite reaction while leaving said inner face and outer face of said filter unobstructed for permitting gases produced by said thermite reaction to exit said crucible at the top of said chamber by entering said filter through said inner face, and exiting said filter to the ambient environment through said outer face.