Heat treating device

Patent metadata

Field	Value
Publication number	US-10557180-B2
Application number	US-201715716707-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	May 1, 2015
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

The present disclosure is characterized by inexpensively treating an ammonia gas contained in an exhaust gas after nitriding without performing combustion, adsorption using an adsorption agent, or the like. A vacuum carburizing device of the present disclosure includes a heating furnace which heats a workpiece, an ammonia gas supply device which supplies an ammonia gas and nitrides the workpiece to the heating furnace, and a thermal decomposition furnace which thermally decomposes the ammonia gas discharged from the heating furnace after nitriding.

First claim

What is claimed is:

1. A heat treating device, comprising:
a heating furnace which heats a workpiece;
an ammonia gas supply device which supplies an ammonia gas to the heating furnace which nitrides the workpiece in the heating furnace; and
a thermal decomposition furnace which thermally decomposes the ammonia gas discharged from the heating furnace after the nitriding,

wherein the thermal decomposition furnace includes:
a reactant which promotes a thermal decomposition reaction of the ammonia gas,
a heating chamber which accommodates and heats the reactant,
an introduction pipe through which the ammonia gas is introduced to the heating chamber,
a vacuum container which surrounds the heating chamber, and
a vacuum pump which evacuates the inside of the vacuum container.

2. The heat treating device according to claim 1 , further comprising:
an exhaust pipe which is provided on the downstream side of the vacuum pump; and
a nitrogen gas supply device which supplies a nitrogen gas to the exhaust pipe.

3. The heat treating device according to claim 1 ,
wherein the reactant is formed in a recessed shape which surrounds a tip of the introduction pipe.

4. The heat treating device according to claim 3 , further comprising:
an exhaust pipe which is provided on the downstream side of the vacuum pump; and
a nitrogen gas supply device which supplies a nitrogen gas to the exhaust pipe.

5. The heat treating device according to claim 1 ,
wherein the reactant includes a flow passage inside the reactant, and
wherein a tip of the introduction pipe is connected to the flow passage.

6. The heat treating device according to claim 5 ,
wherein the flow passage is formed in a spiral shape.

7. The heat treating device according to claim 6 , further comprising:
an exhaust pipe which is provided on the downstream side of the vacuum pump; and
a nitrogen gas supply device which supplies a nitrogen gas to the exhaust pipe.

8. The heat treating device according to claim 5 ,
wherein the flow passage is formed in a zigzag shape.

9. The heat treating device according to claim 8 , further comprising:
an exhaust pipe which is provided on the downstream side of the vacuum pump; and
a nitrogen gas supply device which supplies a nitrogen gas to the exhaust pipe.

10. The heat treating device according to claim 5 , further comprising:
an exhaust pipe which is provided on the downstream side of the vacuum pump; and
a nitrogen gas supply device which supplies a nitrogen gas to the exhaust pipe.

Assignees

• Ihi Corp
• Ihi Machinery & Furnace Co Ltd

Inventors

• Katsumata Kazuhiko

Classifications

• C21D1/06 Primary

  Surface hardening · CPC title

• C23C8/80

  After-treatment · CPC title

• C23C8/32

  of ferrous surfaces · CPC title

• C23C8/26

  of ferrous surfaces · CPC title

• C23C8/22

  of ferrous surfaces · CPC title