JPS61516A - Atmospheric gas generator - Google Patents

Abstract

PURPOSE:To generate a good-quality atmospheric gas for carburizing, etc, in an energy-saving manner by providing a catalyst chamber around the outer periphery of a combustion cylinder, and providing a means for mixing a waste combustion gas with a raw gas and sending the mixture into the catalyst chamber. CONSTITUTION:A converter 1 is formed by providing a catalyst chamber 3 around the outer periphery of a combustion cylinder 2. A burner 6 is furnished to the upper part of the combustion cylinder 2, and a mixed gas of gaseous hydrocarbons and air is sent into the combustion cylinder 2. A waste gas pipe 10 connected to the upper part of a waste combustion gas passage 5 is connected to a raw gas pipe 11 for sending gaseous hydrocarbons such as methane, and a mixed gas of waste gas and gaseous hydrocarbons is sent into the first catalyst chamber 3a through a mixed gas pipeline 13. The mixed gas is passed through the lower part 3c of the catalyst chamber 3 and the inside 3c of the second catalyst chamber, converted endothermically by an endothermic gas generating catalyst, and spouted into the inside of a heating furnace, etc. at the outside of the apparatus as an atmospheric gas from a delivery pipe 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for generating a protective atmosphere gas for heat treatment used in a heating furnace.

Conventionally, the protective atmosphere gas for metals in a heating furnace has been generated by passing a mixed gas of methane-based hydrocarbon gas and air through an endothermic gas generation catalyst to transform it. The gas was heated by a heating device for 10 minutes.
It is metamorphosed through a catalyst heated to 50°C or higher.

However, with conventional protective atmosphere gas generators,
The heating device for heating the catalyst is not used for purposes other than heating the catalyst, making it inefficient in terms of energy conservation. In addition, a large amount of methane-based hydrocarbon gas is required to be fed to the catalyst, and the heating temperature of the catalyst is also high.

This invention was made in consideration of the above circumstances, and
Provided is an atmosphere gas generation device that enables effective use of a heating device for a catalyst used in generating a protective atmosphere gas, reduces the required amount of methane-based hydrocarbon gas, and lowers the heating temperature of the catalyst. The combustion tube is equipped with a combustion tube equipped with a gas combustion burner at the tip, and a catalyst chamber filled with an endothermic gas generation catalyst heated by the combustion tube is installed around the outer circumference of the combustion tube. A transformer is formed, an exhaust gas pipe is provided which is connected to the combustion cylinder and sends the combustion exhaust gas in the combustion cylinder to the outside of the transformer, and this exhaust gas pipe is connected to a raw gas pipe through which methane-based hydrocarbon gas is sent, and this connecting portion is provided. and a catalyst chamber in the shift converter, and a mixed gas pipe for sending mixed gas of exhaust gas and methane-based hydrocarbon gas into the catalyst chamber, and a delivery pipe for sending atmospheric gas transformed by the catalyst to the outside of the shift converter. The gist of the present invention is an atmospheric gas generator characterized by being provided with.

Hereinafter, the atmospheric gas generator 4 according to the present invention will be described.
will be explained based on the illustrated embodiment.

1 and 2 show a first embodiment of an atmospheric gas generator according to the present invention. Reference numeral 1 denotes a shift converter, and the shift converter 1 has a structure in which a catalyst chamber 3 is provided around the outer periphery of a combustion cylinder 2 in the center. A passage 5 is piped between the peripheral wall 4 of the shift converter 1 and the catalyst chamber 3, and is connected to the lower end of the combustion cylinder 2 protruding from the bottom of the catalyst chamber 3 to collect combustion exhaust gas. The combustion tube 2 is equipped with a gas combustion burner 6 at its upper end, and a mixed gas pipe 7 is connected to the burner 6 to supply a mixed gas of air and methane-based hydrocarbon gas such as propane or butane to the burner 6. (arrow mark A in the figure). Catalyst chamber 3
A portion other than the lower portion 3C is partitioned by a partition plate 8, and is divided into a first catalyst chamber 3a and a second catalyst chamber 3b with this partition plate 8 as a border. The first catalyst chamber 3a and the second catalyst chamber 3b are each filled with an endothermic gas generating catalyst heated by the combustion cylinder, and the lower portion 3c is a space. Reference numeral 9 denotes a thermocouple, and the mixing ratio of the mixed gas sent to the burner 6 is adjusted based on the catalyst temperature value detected by the thermocouple 9. The upper part of the combustion exhaust gas passage 5 is connected to an exhaust gas pipe 10 that sends this combustion exhaust gas out of the transformer 1 (arrow B in the figure), and this exhaust gas pipe 10 sends methane-based hydrocarbon gas (arrow B in the figure). C) It is connected to the raw gas pipe 11 outside the transformer 1. The amount of methane-based hydrocarbon gas sent from the raw gas pipe 11 is adjusted according to the atmosphere of the heating furnace by feeding the carbon potential of the atmosphere. The exhaust gas pipe IO and the raw gas pipe 1
The connecting portion 12 of No. 1 is connected to the upper part of the first catalyst chamber 3a by a mixed gas layer 3, and the mixed gas of exhaust gas and methane-based hydrocarbon gas passes through this mixed gas pipe 13 to the second catalyst chamber 3a.
The catalyst is fed into the catalyst chamber 3a (arrow D in the figure). On the other hand, a delivery pipe 14 is provided in the upper part of the second catalyst chamber 3b, and this delivery pipe 14 is connected to a heating furnace (not shown).

That is, the mixed gas sent into the first catalyst chamber 3a is
The catalyst chamber 3a, the lower part 3C1, the second catalyst chamber, and 3b pass through the catalyst chamber 3 in this order (arrow E in the figure), and the endothermic gas generation catalyst filled in the first catalyst chamber 3a and the second catalyst chamber 3b. After being endothermically transformed, this delivery pipe 14 is connected to the transformer 1.
It is sent out (arrow F in the figure) and ejected into a heating furnace (not shown). Note that 15 is a heater for shortening the heating time, but it may not be provided if it is not necessary.

Next, FIGS. 3 and 4 show a second embodiment of the atmospheric gas generator according to the present invention, in which members corresponding to those in the first embodiment are given the same reference numerals. The shift converter 1'' has a structure in which a catalyst chamber 3 filled with an endothermic gas generating catalyst heated by the combustion tube 2'' is provided around the outer periphery of a combustion tube 2'' in the center.In this embodiment, A combustion exhaust gas passage 5'' is formed inside the catalyst chamber 3. That is, the inside of the combustion tube 2'' has a double structure in which the inside and outside are connected to each other at the bottom by an inner tube 2a'', and a gas combustion burner 6 is installed above the inner tube 2a'. The outside of the cylinder is used as a combustion exhaust gas passage 5''. The catalyst chamber 3 has the same structure as the first embodiment described above, and is divided into a first catalyst chamber 3a and a second catalyst chamber 3b by a partition plate 8, and also has a mixed gas pipe 7, an exhaust gas pipe 10, and a raw gas pipe. If ffi The piping of the gas pipe 13 and the delivery pipe 14 is the same as in the first embodiment described above. Since the atmospheric gas generator shown in this second embodiment has a structure in which the catalyst chamber 3 is in contact with the peripheral wall 4 of the shift converter at 1°, the excess amount of heat required for the endothermic reaction of the catalyst can be dissipated to the outside. Therefore, as shown in FIG. 5, it is possible to contribute to the heat retention of the furnace A by attaching it to the workpiece heating terminal end of the continuous bright quenching furnace of the conhair set.

Furthermore, when used as shown in FIG. 5, there is an advantage that the length of the delivery pipe 14 for sending out the generated atmospheric gas can be shortened.

The following table shows the components of the atmospheric gas produced by the apparatus used in the practice of the invention as described above at a catalyst transformation temperature of 780 DEG C. to 950 DEG C.

As shown in the table, the CO2 content is within 1% and the dew point temperature of HLO is within 10℃, which is a sufficiently good value for the atmosphere of the heating furnace, and methane is not used in the catalyst as in the conventional method. The values are comparable to those obtained when a mixed gas of hydrocarbon gas and hydrogen is fed and heated to 1050° C. or higher for metamorphosis.

According to the atmospheric gas generating device as described above, the catalyst heating device, which has conventionally not been used for anything other than heating the catalyst, can be effectively used, and the exhaust gas of this heating device can be used as a raw material for generating the atmospheric gas. Therefore, it can have a significant effect on energy saving. In addition, the amount of methane-based hydrocarbon gas required to generate atmospheric gas can be reduced to an extremely small amount, and the temperature required for transformation (endothermic reaction) into atmospheric gas in the catalyst is also lower than before. A very low temperature is sufficient. Therefore, from this point of view as well, a remarkable effect can be achieved in terms of energy saving, and the atmospheric gas generated is of extremely high quality.

Note that a carburizing atmosphere can be easily generated by adding a small amount of methane-based hydrocarbon gas to the atmospheric gas generated by the apparatus of the present invention.

[Brief explanation of drawings]

FIG. 1 is an explanatory longitudinal cross-sectional view of the first embodiment of the device of the present invention, and the second
The figure is a sectional view taken along the line XX in Fig. 1, and Fig. 3 is a sectional view taken along the line XX of Fig.
FIG. 4 is a longitudinal cross-sectional view of the embodiment, FIG. 4 is a YY cross-sectional view of FIG. 3, and FIG. 2.2°... Combustion tube 3... Catalyst chamber 6... Gas combustion burner

Claims (1)

[Claims] (1) A shift converter is formed by providing a combustion tube equipped with a gas combustion burner at the tip and surrounding the outer periphery of this combustion tube with a catalyst chamber filled with an endothermic gas generation catalyst that is heated by the combustion tube. An exhaust gas pipe is provided that connects to the combustion tube and sends the combustion exhaust gas in the combustion tube out of the transformer, and this exhaust gas pipe is connected to a raw gas pipe that feeds methane-based hydrocarbon gas, and this connecting part and the inside of the transformer are connected. A mixed gas pipe is provided which connects the catalyst chamber of the catalyst chamber and sends a mixed gas of exhaust gas and methane-based hydrocarbon gas into the catalyst chamber, and a delivery pipe is provided which sends the atmospheric gas transformed by the catalyst to the outside of the shift converter. Characteristic atmospheric gas generator.