JP3009497U - Deodorizing equipment with gas soft nitriding equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a deodorizing device for preventing the generation of ammonia odor in a soft nitriding device using a mixed gas of nitrogen gas and carbon dioxide gas. [Composition] In a device for soft nitriding the surface of a work with a gas in which ammonia gas is mixed with a mixed gas of nitrogen gas and carbon dioxide gas, unburned in correspondence with the upper end opening (32) of the exhaust stack (31). A means for burning ammonia gas (35) is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a deodorizing device in a soft nitriding device for soft nitriding the surface of a work such as steel using ammonia gas.

[0002]

[Prior art]

 Generally, when industrially soft-nitriding the surface of a steel sheet or the like (work), an atmosphere gas of the converter furnace gas and ammonia gas is introduced into the heat treatment chamber to convert the converter gas and ammonia gas to the steel sheet (work). A gas soft nitriding method is used in which the surface of the work is nitrided by the reaction.

However, the soft nitriding method that uses the metamorphic furnace gas requires maintenance of the metamorphic furnace that generates the metamorphic furnace gas, and there is a problem that the maintenance of the metamorphic furnace is troublesome. Although the nitriding ability is affected by the amount of hydrogen in the heat treatment chamber, since the shift reactor gas is basically carbon monoxide gas or hydrogen gas, there are many hydrogen components in the shift reactor gas and the nitriding ability is low. Become. Therefore, there is a problem that a large amount of ammonia gas is required for processing in a short time, and a small amount of ammonia gas increases the processing time.

For this reason, in recent years, a gas obtained by adding carbon dioxide gas to nitrogen gas is used as an atmospheric gas, and a deep nitride layer with a high nitriding ability can be obtained by treating the gas in a state with a small hydrogen component. A soft nitriding method has been proposed in which the omission is omitted to simplify the device.

[0005]

[Problems to be solved by the device]

 However, when the metamorphic furnace gas is used as the atmospheric gas, undecomposed ammonia gas is processed by burning the metamorphic furnace gas, so no ammonia odor is generated, but a mixed gas of nitrogen gas and carbon dioxide gas is generated. When nitrogen is used as the atmosphere gas, since nitrogen gas is also an inert gas of carbon dioxide, part of the undecomposed ammonia gas burns at the outlet of the exhaust stack, but most of the ammonia gas does not burn and the ammonia odor is generated. There is a problem that it occurs. The present invention focuses on such a point, and an object thereof is to provide a deodorizing device for preventing the generation of ammonia odor in a soft nitriding device using a mixed gas of nitrogen gas and carbon dioxide gas.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is provided with undecomposed ammonia gas combustion means such as a burner for forming a wire mesh and a frame curtain which are in a red heat state, corresponding to the upper end opening in the exhaust pipe of the nitrocarburizing device. It is characterized by that.

[0007]

[Action]

 In the present invention, since undecomposed ammonia gas burning means such as a wire mesh that becomes a red-hot state or a burner that forms a frame curtain is provided in correspondence with the upper end opening in the exhaust tube of the nitrocarburizing device, a red-hot state is obtained. When a wire net is provided, the ammonia gas comes into contact and burns when it passes through the wire net, and when a frame curtain is provided, it burns when it passes through the frame curtain and leaks ammonia odor. Will be suppressed.

[0008]

【Example】

 FIG. 1 shows an embodiment of the present invention. FIG. 1 is a schematic drawing of a main part and FIG. This gas nitriding apparatus has a carry-in chamber (2) on the inlet side of the heat treatment chamber (1) and a carry-out chamber (3) on the outlet side of the heat treatment chamber (1). ) Is divided by an inner door (4) that can be moved up and down, and the heat treatment chamber (1) and the discharge chamber (3) are also divided by an inner door (5) that can be moved up and down.

An outer door (6) is arranged to be able to move up and down at the carry-in side entrance of the carry-in chamber (2), and an outer door (7) is also arranged to be able to move up and down at the carry-out side exit of the carry-out chamber (3). There is. Each of the doors (4), (5), (6) and (7) is configured to be opened and closed by air cylinders (8), (9), (10) and (11) that operate independently. The inner door (4) and the outer door (6) of the carry-in chamber (2) are selectively opened and closed, and the inner door (5) and the outer door (7) of the carry-out chamber (3) are also selectively opened. It is designed to be opened and closed so that the heat treatment chamber (1) does not directly face the outside. The inner doors (4) and (5) are formed with communication holes (12) having a small opening area.

A treatment gas ejection nozzle (13) is arranged in the heat treatment chamber (1), and a treatment gas supply passage (14) to the treatment gas ejection nozzle (13) is provided with a nitrogen gas supply passage (15). ), A carbon dioxide supply path (16) and an ammonia gas supply path (17), and each gas supply path (15) (16) (17) has a flow control valve (18) (19). ) (20), flow meters (21) (22) (23) and pressure regulating valves (24) (25) (26).

The purging nitrogen gas ejection passages (27) and (28) are branched from the nitrogen gas supply passage (15) to the carry-in chamber (2) and the carry-out chamber (3), respectively. The flow path opening / closing valves (29) (30) are arranged in the paths (27) (28). The passage opening / closing valve (29) arranged in the nitrogen gas ejection passage (27) for purging that is connected to the carry-in chamber (2) is the inner door (4) and the outer door of the carry-in chamber (2). It is designed to be opened / closed in conjunction with the opening / closing operation of (6), and the flow path on-off valve (29) is open when either the inner or outer door (4) (6) is open and operating. The flow path opening / closing valve (30) arranged in the purging nitrogen gas ejection passage (28) connected to the unloading chamber (3) is provided with an inner door (5) of the unloading chamber (3). It is designed to be opened and closed in conjunction with the opening and closing of the outer door (7), and the flow passage on-off valve (30) is opened when either the inner or outer door (5) (7) is open. Keeps the valve open.

In the processing gas supply path (14), an atmosphere gas in which a nitrogen gas and a carbon dioxide gas are mixed at a flow ratio of 9: 1 and an ammonia gas so that the flow ratio of the atmosphere gas is 1: 1. A mixed gas obtained by mixing near gas is allowed to flow. Therefore, the component ratio in the mixed gas is 45 vol% nitrogen gas, 5 vol% carbon dioxide gas, and 50 vol% ammonia gas. Depending on the carbon content of the material to be processed, the mixing ratio of this atmosphere gas should be increased to about 10 vol% if the carbon content is high and the carbon content should be low. The carbon dioxide mixture ratio is reduced to about 2.5%.

An exhaust pipe (31) is led out from the ceiling walls of the carry-in chamber (2) and the carry-out chamber (3). As shown in FIG. 1, the exhaust cylinder (31) has a combustion means including a wire mesh (33) laminated on the upper end opening (32) and a burner (34) arranged corresponding to the wire mesh (33). (35) is located. The burner (34) is arranged toward the lower surface of the wire net (33), and the wire net (33) is heated red hot to about 1200 to 1300 ° C. A hood (36) is arranged above the exhaust stack (31).

In the above embodiment, the combusting means (35) is composed of the laminated wire mesh (33) and the burner (34), but the wire rod of each wire mesh (33) is composed of a heating wire, The combustion means may be composed of only (33).

FIG. 3 shows another embodiment of the present invention in which a frame curtain is formed on the outer periphery of the upper end opening (32) of the exhaust stack (31) above the upper end opening (32). A plurality of burners (34) are arranged, the burner (34) forms the combustion means (35), and a combustible hydrocarbon gas such as propane gas is injected and added to the vicinity of the outlet of the exhaust stack (31). A gas addition port (37) was formed to add combustible hydrocarbon gas to the exhaust gas flowing in the exhaust stack (31) to facilitate burning of undecomposed ammonia gas at the outlet of the exhaust stack (31). It is a thing.

Reference numeral (38) in FIG. 2 is a cooling oil tank arranged in the carry-out chamber (3), and (39) (40) (41) (42) are air cylinders (8) (9) for controlling door opening / closing. ) (10) This is an operation control valve placed in the working air supply path to (11).

[0017]

As described above, according to the present invention, an undecomposed ammonia gas combustion means such as a wire mesh or a burner that forms a frame curtain in a red heat state is provided corresponding to the upper end opening of the exhaust pipe of the nitrocarburizer. Since it is installed, when a wire mesh that becomes red hot is installed, ammonia gas contacts and burns when passing through the wire mesh, and when a frame curtain is installed, when it passes through the frame curtain. It burns into the air and suppresses the leakage of ammonia odor. As a result, it is possible to prevent the work environment from being deteriorated due to the leakage of ammonia odor.

[Brief description of drawings]

FIG. 1 is an extracted view of a main part showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a gas nitriding apparatus.

FIG. 3 is a drawing out of essential parts showing another embodiment.

[Explanation of symbols]

31 ... Exhaust pipe, 32 ... Upper end opening of exhaust pipe, 33 ... Laminated wire mesh,
34 ... Burner, 35 ... Combustion means.

Claims (4)

[Scope of utility model registration request] 1. An apparatus for soft nitriding a surface of a work with a gas obtained by mixing ammonia gas into a mixed gas of nitrogen gas and carbon dioxide gas, in correspondence with an upper end opening (32) of an exhaust stack (31), A deodorizing device in a gas soft nitriding device provided with a means (35) for burning unburned ammonia gas. 2. The upper end opening of the exhaust stack (31) for the combustion means (35)
The deodorizing device for a gas nitrocarburizing device according to claim 1, comprising a laminated wire mesh (33) arranged in the (32) and a burner (34) for heating the wire mesh to a red heat state. 3. The deodorizing device for a gas nitrocarburizing device according to claim 1, wherein the combustion means (35) is a laminated wire net (33) formed of a heating wire. 4. The combustion means (35) is an upper end opening of the exhaust stack (31).
The deodorizing device for a gas nitrocarburizing device according to claim 1, wherein the burner (34) is arranged so as to form a frame curtain on the (32).