JPS6014086B2 - Self-heating constant temperature annealing furnace - Google Patents

Description

[Detailed description of the invention] The present invention relates to a constant temperature annealing furnace utilizing eye heat.

When isothermally annealing a hot forged product (hereinafter referred to as treated material) with a temperature of about 1100 to 115030, it is necessary to rapidly cool the treated material to around 650 oo and then maintain it at the quenching temperature.

By the way, this rapid cooling method includes cold air cooling and hot air cooling, but the former tends to overcool the treated material, which is undesirable as it causes formation of structures such as bainite in the treated material.

On the other hand, although the latter does not have the above-mentioned problems, it usually has a configuration in which a hot air cooling zone and a subsequent wall temperature maintenance zone are arranged consecutively in the longitudinal direction, so the installation space is large, and when hot air cooling Since the cooling heat is discharged outside the furnace, that much heat is wasted, and in order to maintain the temperature holding zone at a constant temperature, it is necessary to provide a special heat source and circulation fan, etc., which is expensive and In constant-temperature anchor treatment of steel, the constant-temperature holding time becomes longer, and therefore (■) the amount of heat increases, which is undesirable from the point of view of energy saving. The present invention has been made in view of the above points, and the present invention has been made in view of the above points.
(Divided into two chambers by a two-stage processing material transport mechanism, the upper part is a hot air quenching chamber, the lower part is a constant temperature holding chamber, and an atmosphere circulation device installed in the furnace ceiling allows each chamber to be divided into two.) The atmosphere inside the furnace is circulated to use the target temperature of the hot forged product as the heat source for the constant temperature holding chamber, while the damper operation of the supply and exhaust duct equipped with a control damper adjusts the atmosphere temperature inside the furnace to a predetermined temperature. In order to save energy, we aim to save energy by reducing the installation space and effectively using the heat of the treated material itself, and by sharing the atmosphere circulation device with the hot air quenching chamber and the constant salt holding chamber, we are able to reduce the cost of constant temperature using target heat. The aim is to provide a hammer.

Next, the present invention will be explained according to the drawings which are one embodiment.

In FIGS. 1 and 2, the furnace body 1 is provided with belt conveyors 5 and 7, which are one conveyance mechanism, in two stages, upper and lower. It is divided into chamber 2 and constant temperature chamber 6 at the bottom.

A processing material loading port 3 is provided on one side of the hot air quenching chamber 2, and the processing material W input from the charging port 3 is transferred to the hot air (6
It is conveyed to the other side by the first belt conveyor 5 while being rapidly cooled by CO ~ 65,000), and is delivered to the second belt conveyor 7 of the constant salt holding chamber 6 from a drop port 4 of the transfer mechanism ``1'', and is transported in the opposite direction to the above. During this time, it is subjected to constant temperature incubation and extracted from an extraction port 8 provided in the temperature holding chamber 6.

Note that 9 and 10 are drive rollers, and 11a to 11d are support rollers. Further, the hot air quenching chamber 2 includes the first to fourth
It consists of belt castles a to d, and in each belt castle, an atmosphere circulation device consisting of a circulation baffle 12 having a large number of nozzle holes 13 facing the treated material and a circulation fan 14 is arranged on the ceiling. In addition, the control dampers 15a, 15b,
Supply/exhaust ducts 16a, 16b, equipped with 15c, 15d,
16c and 16d are provided, and in the first and second belt castles a and b, one end of the general exhaust duct is between the ceiling inner wall and the baffle 12 to introduce outside air, and in the third and fourth belt castles c and d. So,
In order to release the reactor air, there are separate entrances in the Batsuful 12.

Reference numeral 17 denotes a burner installed in each belt castle, and this burner 17 is used at the initial stage of operation when raising the temperature of each belt castle a to d to a predetermined temperature, or when there is less processing material W and the target temperature of the processing material W is low. This is used when there is a shortage and each zone a to d cannot be maintained at a predetermined temperature with only the visual heat of the treated material W.

Next, the operation of the anchor furnace constructed as described above will be explained.

First, each band is heated to a predetermined temperature by igniting the burner 17 and operating the circulation fan 14, the burner 17 is extinguished, and the treated material W, which is a hot forged product at about 1100 to 1150 o'clock, is charged into the charging port. 3 into the hot air quenching chamber 2.

This treated material W is conveyed by the first belt conveyor 5, and in the first and second belt castles a and b, a circulation fan 1
4, the hot air supplied to the lower constant temperature holding chamber 6 quenches the treated material W in the hot air quenching chamber 2, and the control dampers 15a and 15b are controlled so that the temperature of the hot air reaches approximately 650° C. to be introduced within. On the other hand, the hot air in the constant temperature holding chamber 6, which has reached about 65,000 ℃, is circulated through the lower temperature holding chamber 6 by the circulation fan 14, and is again supplied to the hot air quenching chamber 2.

Furthermore, in the third and fourth bands c and d, as above,
The hot air in temperature holding chamber 6 is about 62,500 and 6, respectively.
00qo, control damper 1 5c, 15d
The atmosphere inside the furnace is evacuated by controlling the

In this way, the treated material W is approximately 1,100 to 1,150 do
It is quenched to about 650℃ in the hot air quenching chamber 2, and the droplet 4
It is delivered onto the second belt conveyor 7 in the overflow holding chamber 6 via. As mentioned above, the temperature of this constant temperature chamber 6 is as follows.
Due to the cooling heat of the treated material W, the atmosphere in each band is approximately 650°C in the range corresponding to the first and second band castles a and b, and the temperature in the third and fourth band castles c, as shown in FIG. The range corresponding to d is about 625q0 and about 600q0, respectively, so
The processing material W, which has been cooled to about 650 qo, is maintained in this state during the process of being conveyed by the second belt conveyor 7, is cooled, and is discharged from the extraction port 8.

The conveyance speed of the belt conveyor is as shown in Figure 4.
The first belt conveyor 5 is faster than the second belt conveyor 7 because various heat patterns are adopted depending on the material W to be treated, and the speeding time is shorter than the holding time.

In the examples, a belt conveyor system is used as the processing material transport mechanism, but a transport mechanism such as a roller hearth system may be adopted, and the processing material transfer mechanism may also be compatible with the transport mechanism. It can be configured arbitrarily. As is clear from the above explanation, according to the constant temperature phosphor annealing apparatus using constant heat of the present invention, since the hot air lining chamber and the fence temperature holding chamber are formed in the upper and lower parts of the furnace, the space for arranging the furnace is small. Moreover, the heat source of the constant temperature chamber is the heat of the treated material during hot air cooling, and since the atmosphere inside the furnace is circulated by a circulation fan common to both chambers, it is possible to not only save energy but also make the furnace inexpensive. can.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical cross-sectional view of a constant-temperature lying anchor furnace using constant heat according to the present invention, Fig. 2 is a cross-sectional view of Fig. 1, and Fig. 3 is a graph showing the temperature of the treated material and the temperature of the constant temperature holding chamber. , FIG. 4 is a constant temperature dawn anchor treatment cycle. 1...Furnace, 3...Charging port, 2...Hot air quenching chamber, 4
... Transfer mechanism, 5... First transfer mechanism, 6... Wall temperature holding chamber, 7... Second transfer mechanism, 8... Extraction port, 12
...Circulation baffle, 14...Circulation fan, 16a-16
d... Duct, a to d... First to fourth belt castles, W... Treated material. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 Two stages of processing material transport mechanisms each having a different transport direction are arranged in the furnace, and the upper part is a hot air quenching chamber having a processing material loading port, and the lower part is a constant temperature holding chamber having a processing material extraction port, and the hot air is A transfer mechanism is provided at the extraction side end of the quenching chamber to supply the processed material from the upper transfer mechanism to the lower transfer mechanism of the constant temperature holding chamber, and an atmosphere circulation device consisting of a buffer and a circulation fan is connected to the ceiling of the furnace. A constant-temperature annealing furnace utilizing self-heating, characterized in that a plurality of zones are formed by installing and arranging the zones, and each zone is connected to an air supply/exhaust duct equipped with a control damper.