JPH0280551A - Equipment for forming oxide film on steel - Google Patents

Abstract

PURPOSE:To remove energy loss and to miniaturize equipment by directly burning a gaseous raw material in a heat treatment furnace in which a material to be treated is placed to form an exothermic gas and using the resulting heat energy for heating in the heat treatment furnace. CONSTITUTION:At the time of forming nonprogressive iron oxide (Fe3O4) on the surface of a steel as a material to be treated in a heat treatment furnace, an oxide film is formed on the steel by using one furnace in the case when an exothermic gas is propane gas as LPG, or town gas. For example, burners 13 for burning gaseous raw material are attached to the walls of a heat treatment furnace 12 to blow the exothermic gas into the furnace 12 and a material 14 to be treated is disposed in the furnace 12 to undergo formation of oxide film. At this time, a compact exothermic gas producer 16 with a burner 15 is separately provided in the case when the adjustment of the quantity of the exothermic gas generated and the adjustment of temp. in the treatment furnace 12 are necessary, and the adjustment of the temp. in the furnace and also the adjustment of the quantity of the atmospheric gas generated can be carried out by means of a cooling device 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oxide film forming apparatus for forming a non-progressive oxide on the surface of steel.

[Conventional technology]

There is an apparatus shown in FIG. 3 as an apparatus for forming non-progressive oxide II (steel tetroxide) on the surface of steel products for rust prevention. This equipment consists of an exothermic gas generating furnace (2) equipped with a burner (1) on the furnace wall that burns raw material gas to generate exothermic gas, and a heat treatment furnace that forms an oxide film on the object to be treated (3). (4), the above-mentioned furnaces (2) and (4) are connected by a heat-generating gas supply pipe (5), and a cooling device (6) and a heating device are installed in the middle of the above-mentioned heat-generating gas supply pipe (5). (7) is provided, and the cooling device (6) and heating device (7) are adjusted to obtain exothermic gas suitable for forming an oxide film. This device supplies an appropriate amount of air to the raw material gas and burns it to generate exothermic gas consisting of CO, H20, N2, and GO1H2.

If the amount (dew point) of this exothermic gas is controlled to an appropriate value and supplied into the heat treatment furnace (4), and the steel is heat treated in this atmosphere, the surface of the steel will become Fe304 in the presence of H2O. , an oxide film is formed on the surface of the steel. The equipment currently used industrially cools the generated gas with a cooling device (6) such as a scrubber installed between the exothermic gas generator (2) and the heat treatment furnace (4) to bring the dew point to about The atmosphere gas is adjusted to 60°C, and heated indirectly with a heating device (7) to prevent condensation from falling below the dew point to a heat treatment furnace (4).
The inside of the heat treatment furnace (4) is heated to about 600° C. to process the object. Note that (8) is an outlet for exhaust gas from the processing furnace (4).

[Problem to be solved by the invention]

In conventional equipment, the exothermic gas generation furnace that generates the atmospheric gas and the heat treatment furnace that processes the workpiece are separate bodies, which not only results in energy loss (but also has the disadvantage of making the equipment large). be.

The conventional device described above includes a cooling device (6) and a heating device ( 7)
is installed in the middle of the exothermic gas supply pipe (5), and the processing furnace (4)
Adjusting the atmospheric gas inside.

However, when using LPG propane or city gas, which has stable components, it is possible to obtain exothermic gas with components suitable for forming an oxide film on steel simply by adjusting the amount of combustion gas supplied with a gas burner. It has been found that the cooling device (6) and heating device (7) for component adjustment in the apparatus shown in FIG. 3 are no longer necessary.

The present invention uses propane and city gas, which have stable compositions, as raw materials, eliminates the need for a cooling device or heating device for moisture adjustment, and is capable of forming an oxide film on steel using a single furnace. This is what we intend to provide.

Means for Solving Problem c] The present invention directly burns raw material gas to generate exothermic gas in a heat treatment furnace that accommodates the object to be treated, and uses the thermal energy generated during combustion as described above. It was used as a heating source for a heat treatment furnace.

[Effect]

If an appropriate amount of air is supplied to the combustible components in the raw material gas and the combustible components are combusted, the generated gas becomes an exothermic gas containing CO2, N20, N2, and C01H2 as main components.

For example, if steel is heat-treated in an atmosphere of this generated gas, a desired oxide film is formed through 3Fe +4820 =Fe304 +4H2, and these reactions are carried out in one furnace.

〔Example〕

A first embodiment will be described with reference to FIG.

(12) is a processing furnace in which a burner (13) for burning raw material gas is attached to the furnace wall and exothermic gas is blown into the furnace. (14) is an object to be treated, which is installed in a heat treatment furnace (12) that burns the raw material gas to generate exothermic gas. In addition, in case it becomes necessary to adjust the amount of generated exothermic gas and the temperature inside the heat treatment furnace, a small exothermic gas generating furnace (16) having a separate burner (15) is attached. In this case, a gas cooling device such as a scrubber (
17) to adjust the temperature inside the heat treatment furnace and the amount of atmospheric gas generated. FIG. 2 shows a second embodiment, and in this case as well, an auxiliary heating device (18) and an indirect cooling device (19) using a cooling medium may be provided as necessary.

Note that (20) is the exhaust port for exhaust gas.
If there is insufficient water, humidifying water may be added as needed.

〔Effect of the invention〕

Since the raw material gas components of the natural gases currently available on the market, such as LPG and city gas, are stable, it is relatively difficult to use them in steel oxide film forming equipment that uses such gases as raw materials. An exothermic gas is obtained as combustion gas which is easily passed through the device. Therefore, cooling equipment and heating equipment for component adjustment are basically unnecessary, and the exothermic gas generating furnace and heat treatment furnace can be integrated into an integrated structure.As a result, energy loss is eliminated and the entire equipment is made more compact. It is industrially advantageous as it reduces the cost of construction.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an apparatus configuration of a first embodiment of the present invention, FIG. 2 is a schematic diagram of an apparatus configuration of a second embodiment of the invention, and FIG. 3 is a configuration diagram of an oxide film forming apparatus according to the prior art. It is a factor. (12) - Heat treatment furnace, (13) (15) ~ Burner, (14) - Workpiece, (16> Exothermic gas generating furnace, cooling device, heating device, discharge port. Patent applicant Osaka Gas Matsushita Electric Industrial Co., Ltd. Agent Gangwon Province, (14fζj"lji'

Claims (1)

[Claims] (1) The material gas is directly combusted to generate exothermic gas in the heat treatment furnace that houses the object to be treated, and the thermal energy generated during combustion is used to heat the heat treatment furnace. Equipment for forming oxide film on steel.