US 12,420,337 B2
Sealed furnace
Nathan Woodard, Medford, MA (US); Jonah Samuel Myerberg, Lexington, MA (US); Emanuel M Sachs, Burlington, MA (US); Richard Remo Fontana, Cape Elizabeth, MA (US); Robert Edward Weiss, San Francisco, MA (US); Yet-Ming Chiang, Burlington, MA (US); Stephen Dipietro, Amherst, MA (US); and Nicholas Graham Bandiera, Burlington, MA (US)
Assigned to Desktop Metal, Inc., Burlington, MA (US)
Appl. No. 17/429,763
Filed by Desktop Metal, Inc., Burlington, MA (US)
PCT Filed Feb. 11, 2020, PCT No. PCT/US2020/017714
§ 371(c)(1), (2) Date Aug. 10, 2021,
PCT Pub. No. WO2020/167802, PCT Pub. Date Aug. 20, 2020.
Claims priority of provisional application 62/911,696, filed on Oct. 7, 2019.
Claims priority of provisional application 62/911,665, filed on Oct. 7, 2019.
Claims priority of provisional application 62/830,303, filed on Apr. 5, 2019.
Claims priority of provisional application 62/804,181, filed on Feb. 11, 2019.
Prior Publication US 2022/0008991 A1, Jan. 13, 2022
Int. Cl. B22F 3/00 (2021.01); B22F 3/10 (2006.01); B33Y 40/20 (2020.01); F27B 5/04 (2006.01); F27B 5/08 (2006.01); F27B 5/18 (2006.01); F27D 1/00 (2006.01); F27D 99/00 (2010.01)
CPC B22F 3/003 (2013.01) [B22F 3/1021 (2013.01); B33Y 40/20 (2020.01); F27B 5/04 (2013.01); F27B 5/08 (2013.01); F27B 5/18 (2013.01); F27D 1/0033 (2013.01); F27D 99/0073 (2013.01); B22F 2201/20 (2013.01)] 33 Claims
OG exemplary drawing
 
1. A high-temperature high-purity vacuum furnace for heating parts over a range of high furnace temperatures, comprising:
an arrangement of furnace insulation with furnace heaters disposed therein, that when heating parts define a hot zone therein that is heated by the furnace heaters to a temperature that exceeds 800C for at least a portion of a furnace heating cycle,
an openable and closeable sealed vacuum retort that while closed is contained during the furnace heating cycle within the hot zone and is surrounded by an outside ambient air originating from outside the vacuum furnace, and is composed of a material that is:
(i) non-porous and thus impervious to diffusion of outside gases, and
(ii) capable of withstanding vacuum pressure throughout the furnace heating cycle;
wherein the sealed vacuum retort while closed defines an inner volume as a hollow interior in fluid communication with an inlet tube for injecting process gas therein and an outlet tube for applying vacuum thereto;
wherein each of the inlet tube and the outlet tube extends from the hot zone, towards an exterior of the furnace, through at least a portion of the arrangement of furnace insulation; and
wherein when the retort is closed the inner volume is vacuum sealed from the outside ambient air by a main retort seal that is within the hot zone that blocks contamination, of the process gas within the inner volume, by leakage of outside ambient air into the inner volume, to a sufficient degree to prevent adverse effects on parts quality by the outside ambient air.