Sealed furnace

Patent metadata

Field	Value
Publication number	US-2022008991-A1
Application number	US-202017429763-A
Country	US
Kind code	A1
Filing date	Feb 11, 2020
Priority date	Feb 11, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

A furnace may include an outer wall defining a chamber, the chamber including an internal cavity configured to receive one or more parts, at least one heater positioned within the chamber, the at least one heater being configured to generate temperatures of at least about 800 degrees Celsius within the internal cavity, and a vacuum pump configured to apply a vacuum to at least a portion of the chamber. The furnace may also include at least one layer of inner insulation and at least one layer of outer insulation disposed outward of the inner insulation with respect to the chamber, the at least one layer of outer insulation being sealed with respect to the at least one layer of inner insulation.

First claim

What is claimed is:

1 . A furnace, comprising:
an outer wall defining a chamber, the chamber including an internal cavity configured to receive one or more parts; at least one heater positioned within the chamber, the at least one heater being configured to generate temperatures of at least about 800 degrees Celsius within the internal cavity; a vacuum pump configured to apply a vacuum to at least a portion of the chamber; at least one layer of inner insulation; and at least one layer of outer insulation disposed outward of the inner insulation with respect to the chamber, the at least one layer of outer insulation being sealed with respect to the at least one layer of inner insulation.

2 . The furnace of claim 1 , further comprising a barrier gaseously isolating the at least one layer of outer insulation from the at least one layer of inner insulation to reduce an amount of moisture, gas, or binder that is absorbed by or released from the outer insulation.

3 . The furnace of claim 2 , wherein the barrier has a cylindrical shape.

4 . The furnace of claim 2 , wherein the barrier includes a continuous seal.

5 . The furnace of claim 2 , wherein the barrier includes a lap seal.

6 . The furnace of claim 1 , further comprising a retort disposed inward with respect to the at least one layer of inner insulation, the retort having a porous surface.

7 . The furnace of claim 6 , wherein the porous surface includes a coating to reduce a size of pores of the porous surface.

8 . The furnace of claim 1 , further comprising a retort, wherein the retort includes SiC.

9 . The furnace of claim 1 , further comprising a controller configured to control the vacuum pump.

10 . The furnace of claim 1 , further comprising at least one of a heater or insulation configured to raise a temperature of a valve downstream of a hot zone of the furnace and upstream of a vacuum pump of the furnace.

11 . The furnace of claim 1 , further comprising:
a retort including a first portion and a second portion that cooperatively define a hollow interior when in a closed position; a first seal configured to seal the hollow interior with respect to an exterior of the retort when the first portion and the second portion are in the closed position; and a second seal configured to seal the hollow interior with respect to the exterior of the retort when the first portion and the second portion are in the closed position, wherein the second seal surrounds the first seal.

12 . A retort for a furnace, comprising:
a retort base; a retort body separably coupleable to the retort base; a retort seal disposed between the retort base and the retort body when the retort is in a closed position with the retort base coupled to the retort body, the retort seal including an inner seal and an outer seal; a first conduit fluidly connected to the retort base and configured to supply an inert gas; a second conduit fluidly connected to the retort base and configured to apply a vacuum to an interior of the retort; and a third conduit fluidly connected to the retort seal and configured to supply an inert gas between the inner seal and the outer seal.

13 . The retort of claim 12 , further comprising a fourth conduit fluidly connected to the retort seal, wherein the fourth conduit is configured to apply a vacuum pressure to remove the inert gas between the inner seal and the outer seal.

14 . The retort of claim 12 , wherein the inner seal includes a gasket.

15 . The retort of claim 12 , further comprising a groove formed within the retort, wherein the groove is positioned between the inner seal and the outer seal and is in fluid communication with the third conduit and configured to receive a supply of inert gas from the third conduit.

16 . The retort of claim 15 , further comprising a gap fluidly connected to the groove, the gap is formed by a pair of opposing surfaces of the retort.

17 . The retort of claim 12 , wherein at least one of the retort base or the retort body includes one or more of SiC, alumina, reaction bonded siliconized SiC, or nitride-bonded SiC.

18 . The retort of claim 12 , further comprising a conduit seal between the retort body and at least one of the first conduit, the second conduit, or the third conduit.

19 . A furnace, comprising:
the retort of claim 12 ; at least one layer of insulation; and at least one furnace heater, wherein the at least one layer of insulation defines a hot zone inward of the at least one layer of insulation, wherein the retort is positioned at least partially within the hot zone.

20 . The furnace of claim 19 , wherein the retort is positioned entirely within the hot zone.

Assignees

• Desktop Metal Inc

Inventors

• Woodard Nathan
• Myerberg Jonah Samuel
• Sachs Emanuel M
• Fontana Richard Remo
• Weiss Robert Edward
• Chiang Yet-Ming
• Dipietro Stephen
• Bandiera Nicholas Graham

Classifications

• Y02P10/25

  Process efficiency · CPC title

• B22F2201/20

  Use of vacuum · CPC title

• F27B5/04 Primary

  adapted for treating the charge in vacuum or special atmosphere · CPC title

• F27D1/0033

  Linings or walls comprising heat shields, e.g. heat shields · CPC title

• B22F3/003 Primary

  Apparatus, e.g. furnaces (in general F27B) · CPC title