JPS6260445B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a non-oxidizing heat treatment furnace.

When heat treatment, such as brazing, is performed using non-oxidizing (reducing) furnace air, a bright product with excellent quality, dimensions and other properties can be obtained due to the oxidation-preventing effect of the base material and brazing material. For this reason, non-oxidizing furnaces are widely used for heat treatments such as brazing and annealing, and in particular, from the viewpoint of productivity and labor saving, a tunnel furnace 50 and a conveyor belt 51 are combined as shown in Fig. 1. A conventional continuous furnace of this type is operated by installing a separate atmospheric gas generator 52 outside the furnace, and moving the workpiece inside the furnace through a heat-generating mechanism. 5
3, the raw material gas and air are mixed and burned in the combustion device 54 of the atmospheric gas generator 52 to create an atmospheric gas, and this is introduced into the furnace.

However, in this method, the generation of atmospheric gas and the heating of the material to be processed are performed in separate equipment and processes, and in particular, the heat generated from the high-temperature combustion of the raw material and air can be wasted in the combustion chamber of the atmospheric gas generator. Since the consumption amount tends to increase in proportion to the improvement in the processing capacity of the furnace, there is a problem that a large amount of energy is required as a whole to carry out the intended heat treatment. Because it is a complex device that requires a chamber, a water sprinkling mechanism, a heat exchange member, a pump, etc., the equipment as a whole is expensive, and it also requires a large installation area because it has a large volume and occupies a high proportion of the atmosphere generation device. There was this problem.

The present invention was devised after repeated research in view of the above-mentioned circumstances, and aims to provide an energy-saving continuous furnace that can efficiently perform non-oxidation heat treatment without the need for a separate atmospheric gas generator. be.

For this purpose, the present invention causes direct reducing flame combustion in a continuous furnace to preheat the material to be treated using the combustion heat, and also purifies the combustion exhaust gas and introduces it into the furnace. This method allows effective non-oxidation heat treatment to be carried out.

That is, in the present invention, a preheating chamber and a heating chamber are formed through a partition wall in a furnace main body having an inlet and an outlet connected to each other in the front and rear, and a burner for forming a reducing flame and a suction/discharge of combustion exhaust gas are provided in the preheating chamber. The apparatus is characterized in that the suction and discharge part is connected to the outlet part through a gas purification device outside the furnace.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figures 2 to 4 show the non-oxidizing heat treatment furnace according to the present invention, in which 1 is a furnace body made of refractory material, and an inlet portion 2 is connected to the front side of the furnace body 1. At the same time, an outlet section 3 surrounding a water-cooled box 4 on the outer periphery is connected to the rear side.

Reference numeral 5 denotes a transfer mechanism for sequentially moving the material to be treated to the inlet section 2, the furnace main body 1, and the outlet section 3. In this embodiment, a conveyor belt such as a mesh belt is used.

Such a configuration is similar to the conventional heating furnace, but in the present invention, a partition wall 6 is provided at the inner middle part of the furnace body 1 and descends to the extent that allows the passage of the material to be processed. A preheating chamber 7 and a heating chamber 8 are divided into a preheating chamber 7 and a heating chamber 8, and a heating mechanism (an electric heater in this embodiment) 9 is disposed on the inner wall of the heating chamber 8.
Burners 10 and 10' are inserted in the preheating chamber to obtain reducing flame combustion with a mixture of raw material (eg, propane gas) and air. A suction/discharge section 11 for forcibly taking out reducing flame combustion exhaust gas is provided elsewhere in the preheating chamber 7, while coolers 14a, 14b, 1
4c, a filter 15, dryers 16a, 16b, and a blower 17 are connected in series with piping. A purified gas insertion part 19 is provided at the outlet part 3 of the main body 1, and the gas insertion part 19 and the blower 17 are connected to each other.
The discharge side of the flowmeter is connected via a flowmeter 18.
Note that the gas purification device 13 may of course be provided with a refrigerator or a CO ₂ removal device.

Here, the preheating chamber 7 includes burners 10 and 10'.
A heat-resistant perforated plate 21 is placed in the area below the spout of the upper burner 10 via a support member 20 so that the combustion heat of the reducing flame emitted from the burner can be uniformly distributed throughout the room and provide a sufficient amount of heat to the object to be treated. In addition, a heat-resistant perforated plate 22 is mounted above the spout of the lower burner 10' at the same height as the transfer level of the object to be treated.

In addition, in the drawings, 23 is a furnace core tube installed inside the heating chamber 8, which is necessary when the heating mechanism 9 is a gas burner, but not necessarily when it is an electric heater.

In addition, depending on the case, the outlet part 3 near the furnace main body 1
Of course, it is also possible to provide an inlet for replacement gas at an appropriate location to expel the internal air at the start of work.Furthermore, a gas curtain or shutter may be provided on the partition wall 6, so that the preheating chamber 7 can be expelled at the start of work. It may be made independent of the heating chamber 8 to promote the formation of a reducing flame and the suction and discharge of exhaust gas.

Since the present invention has the above-described configuration, when performing non-oxidizing heat treatment such as brazing, annealing, and sintering, the transfer mechanism 5 is driven to transfer the workpiece from the inlet section 2 to the outlet section. At the same time, the heating mechanism 9 and the burners 10, 10' are operated to supply the burner 10, 10' with a mixture with an air-fuel ratio in excess of the raw material. A reducing flame is formed by the burners 10 and 10', and reducing combustion gas is continuously ejected from the burners 10 and 10' into the preheating chamber.
The object to be processed passing through the preheating chamber 7 is directly and rapidly heated by the combustion gas, and its temperature rises.

On the other hand, the preheating chamber 7 is provided with a gas suction/discharge section 11 and a forced suction force is applied by the blower 17, so that the reducing flame combustion exhaust gas is immediately discharged from the gas suction/discharge section 11 to the outside of the furnace after imparting heat to the object to be treated. guided by,
Moisture is condensed and removed while passing through coolers 14a, 14b, 14c, impurities are removed by filter 15, and finally the dew point is adjusted to a predetermined dew point by dryers 16a, 16b. In this process, high purity reduction is achieved. It is converted into a sexual gas and supplied to the outlet section 3. The reducing gas supplied to the outlet section 3 becomes a gas flow attracted by the heat of the heating chamber 8, and while passing through the outlet section 3, it is cooled by heat exchange with the object to be treated, and the gas itself is moderately The temperature is raised to , and the heat is continuously supplied to the heating chamber 8 . Therefore, the object to be treated is rapidly heated by the reducing flame in the preheating chamber 7, and then
In the heating chamber 8, the preheated exhaust gas is efficiently heated to a predetermined temperature by a purified reducing atmosphere, and furthermore, at the outlet section 3, it is efficiently cooled under non-oxidizing conditions by the room cooling effect due to the gas flow in the same atmosphere and the water cooling effect on the outer periphery, and is continuously cooled. It is something that is taken out.

According to the present invention explained above, the partition wall 6
A preheating chamber 7 and a heating chamber 8 are formed through the preheating chamber 7, and the preheating chamber 7 is provided with burners 10, 10' for forming a reducing flame and a combustion exhaust gas suction and discharge section 11, and the suction and discharge section 11 is connected to the gas outside the furnace. Outlet section 3 via purifier 13
By connecting it to , you can get the following excellent effects.

The mixture of raw materials and air is directly combusted with a reducing flame in the furnace body, and the combustion heat energy is used to rapidly heat the material to be processed. After preheating, the exhaust gas is purified and used as non-oxidizing furnace air. There is no wastage of energy, the electric power of the heating mechanism in the heating chamber can be saved, and the cooling effect after heating can be improved, so that it is possible to achieve overall significant energy savings.

This eliminates the need for a large-volume combustion device, which is a key part of the atmosphere generation device, and the remaining components can be housed in the support frame of the furnace body, making this type of non-oxidation heat treatment furnace compact and requiring only a small installation area. can do.

Eliminates the need for complex and expensive combustion equipment,
Further, since the length of the furnace can be shortened and the number of heating mechanisms can be reduced, equipment costs and operating costs can be reduced.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing a conventional non-oxidation heat treatment furnace;
FIG. 2 is a longitudinal sectional side view showing an embodiment of the non-oxidation heat treatment furnace according to the present invention, FIG. 3 is a sectional view along the line shown in FIG. 1, and FIG. 4 is a sectional view taken along the line shown in FIG. 1. be. 1...Furnace body, 2...Inlet part, 3...Outlet part,
6... Partition wall, 7... Preheating chamber, 8... Heating chamber, 1
1... Suction discharge unit, 13... Gas purification device, 19
...Gas insertion part for purified gas.

Claims (1)

[Claims] 1. A preheating chamber 7 and a heating chamber 8 are formed through a partition wall 6 in the furnace body 1, which has an inlet section 2 and an outlet section 3 connected in the front and rear, and a burner 10 for forming a reducing flame in the preheating chamber 7,
10' and a combustion exhaust gas suction/discharge section 11, the suction/discharge section 11 being connected to an outlet section 3 via a gas purification device 13 outside the furnace.