JPH1017925A - Continuous heat treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the space and energy consumption of a continuous heat treatment furnace, to reduce the equipment cost and the driving cost and to enable uniform heating. SOLUTION: This continuous heat treatment furnace is composed of a two- step conveying type high temp. heating furnace 2 provided with a horizontal conveying means in two stages at the upper and the lower parts in the furnace so as to be capable of conveying materials (a) to be heated in the upper and the lower stages, a two-stage conveying middle temp. heating furnace 10 provided with a horizontal conveying means in two stages at the upper and the lower parts same as the high temp. heating furnace, an elevating/lowering table 6 provided at a charging hole of the high temp. heating furnace so as to divide the material to be heated into the upper stage or the lower stage, a quenching device 13 arranged between the high temp. heating furnace and the middle temp. heating furnace so as to dip the heated material extracted from the high temp. heating furnace into an oil vessel 18 and a cooling device 24 arranged at an extruding hole of the middle temp. heating furnace so as to dip the heated material extracted from the middle temp. heating furnace into a water vessel 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous heat treatment furnace for transferring a metal product into a furnace and performing heat treatment such as baking and normalizing.

[0002]

2. Description of the Related Art Continuous heat treatment furnaces such as roller hearth furnaces and conveyor furnaces in which horizontal conveying means such as conveying rollers and mesh belts are provided in a furnace are generally very difficult to uniformly heat the object to be heated. Required a long furnace length. For this reason, there is a problem that a space is required and a construction cost is increased. In addition, since a large furnace body has a large amount of heat dissipation from the furnace wall surface area, there is a problem that the heat energy cost is further increased.

Further, the conventional continuous heat treatment furnace is provided with a fan for stirring the gas in the furnace for the purpose of uniform heating and for improving the temperature distribution in the furnace, but a heat-resistant fan is installed and operated. However, there was a problem that high cost was required.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it possible to save space and energy in a continuous heat treatment furnace, to reduce equipment costs and operation costs, and to make uniform heating possible. It is.

[0005]

For this purpose, the continuous heat treatment furnace according to the present invention is provided with two horizontal transfer means in the furnace so that the object to be heated can be transferred in the furnace length direction in each of the upper and lower steps. A two-stage transfer type high-temperature heating furnace, a two-stage transfer type medium-temperature heating furnace in which horizontal transfer means are provided in two upper and lower stages similarly to the high-temperature heating furnace, and a charging port of the high-temperature heating furnace. An elevating table that is provided and distributes the heated object to the upper or lower stage,
A quenching device provided between the high-temperature heating furnace and the medium-temperature heating furnace to immerse the heat-extracted object extracted from the high-temperature heating furnace in an oil bath, and provided at an extraction port of the medium-temperature heating furnace. A cooling device for immersing the object to be heated extracted from the medium-temperature heating furnace in a water tank. Further, the present invention is characterized in that in the continuous heat treatment furnace, a fan is provided between the high-temperature heating furnace and the medium-temperature heating furnace to cool an object to be heated extracted from the high-temperature heating furnace. Further, in the present invention, in a continuous heat treatment furnace in which an object to be heated is conveyed in the furnace length direction, at least one pair of high-speed burners that blows out a combustion flame at a high speed is provided between an upper portion of one side wall of the furnace body and the other side wall. By providing a swirling flow of the combustion flame in the furnace by being opposed to the lower portion, the high-speed burners are arranged in the furnace lengthwise direction so that the object to be heated is conveyed as it is conveyed. It is characterized in that an anti-opposed swirling flow can be alternately bathed in the hot matter.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described for a continuous hardening and tempering furnace of a roller hearth two-stage transfer type.
In this continuous heat treatment furnace, the object to be heated can be conveyed in the furnace in two upper and lower stages. FIG. 1 is an overall vertical sectional view, FIG. 2 is a sectional plan view taken along line AA of FIG. 1 is a sectional view taken along line BB of FIG. 1, FIG. 4 is a sectional view taken along line CC of FIG. 1, and FIG.
FIG. In the figure, 1 is a charging table, 2
Are transport rolls 3, 3, 3, ... and 4, 4, 4,
Are high-temperature heating furnaces provided in two upper and lower stages, 5 is a charging inlet provided at one end of the high-temperature heating furnace 2, and 6 is a heating object a received from the charging table 1 in the upper stage. Transport roll 3,
3, 3,..., An elevating table provided in front of the loading port 5 for sorting on the upper or lower transport rolls 4, 4, 4,. It is. Here, the heat target a indicates a thing in which a large number of forged products are stored in a basket.

The inside of the high-temperature heating furnace 2 is divided into four heating zones 2a to 2d along the furnace length direction. As shown in FIG. 3, a high-speed burner 9L is provided above one side wall 8L of the heating zone 2a, and a high-speed burner 9R is provided below the other side wall 8R. High-speed burners 9L, 9R
Is capable of blowing a combustion flame into the furnace at a high speed of 80 m / s or more, thereby forming a swirling flow of the combustion flame as indicated by an arrow in the furnace.

As shown in FIG. 4, a high-speed burner 9L is provided on one side wall 8L of the heating zone 2b following the heating zone 2a.
A high-speed burner 9R is provided on the upper part of the other side wall 8R.
Is provided. For this reason, in the heating zone 2b, the combustion flame forms a swirling flow on the opposite side to the heating zone 2a as illustrated. Further, in the heating zone 2c, a high-speed burner 9L is provided above the side wall 8L, and a high-speed burner 9R is provided below the side wall 8R, whereby a swirling flow is formed opposite to the heating zone 2b. In the heating zone 2d, the side wall 8L is provided. High-speed burner 9 at the bottom of
L is provided, and a high-speed burner 9R is provided above the side wall 8R, whereby a swirling flow that is opposite to the heating zone 2c is formed. In addition, 19 is an exhaust gas port opened in the ceiling of each of the heating zones 2a to 2d.

Reference numeral 10 denotes a two-stage transfer type medium temperature heating furnace in which transport rolls 3, 3, 3,... And transport rolls 4, 4, 4,. A charging port provided at one end of the intermediate temperature heating furnace 10 and an extraction port 12 provided at the other end. In addition, the inside of the middle temperature heating furnace 10 has three heating zones 1 along the furnace length direction like the high temperature heating furnace 2.
A high-speed burner 9R is provided above one side wall 8R of the heating zone 10a, and a high-speed burner 9L is provided below the other side wall 8L. Also,
In the heating zone 10b, a high-speed burner 9L is provided above the sidewall 8L, and a high-speed burner 9R is provided below the sidewall 8R. In the heating zone 10C, a high-speed burner 9R is provided above the sidewall 8R, and a high-speed burner 9L is provided below the sidewall 8L. Is provided. For this reason, the swirling flow formed in the furnace by the combustion flame blown out from the high-speed burner 9L and the high-speed burner 9R changes the turning direction in each heating zone in order similarly to the high-temperature heating furnace 2. In addition, 29 is each heating zone 10a-1.
It is an exhaust gas port opened in the ceiling of 0c.

Reference numeral 13 denotes a quenching device comprising a quenching chamber 14, an oil draining chamber 15, and a burn-off chamber 16 provided between the high temperature heating furnace 2 and the medium temperature heating furnace 10. Quenching room 14
Inside, an elevator 17 for supporting and raising and lowering the object to be heated a is provided, and an oil tank 18 is provided immediately below the elevator.
The oil draining chamber 15 has a space for waiting for the heat target a, and quenching oil adhering to the heat target a is dropped in this space and returned to the oil tank. Also, the side wall 8R of the burn-off chamber 16
A high-speed burner 9R is provided at the upper part of the burner, and a high-speed burner 9L is provided at a lower part of the side wall 8L. A swirling flow is also formed in the burn-off chamber 16 by the combustion flame blown out from the high-speed burners 9R and 9L. Reference numerals 20 and 21 denote exhaust gas ports provided on the ceiling of the oil drain chamber 15 and the burn-off chamber 16.

Reference numeral 23 denotes an electric fan provided on the ceiling of the quenching chamber 14, and blows a cooling gas in the quenching chamber 14 onto a heated object a supported on the elevator 17 by the fan 23. It is configured to be able to. You.

Reference numeral 24 denotes an extraction port 1 of the medium temperature heating furnace 10.
2, the cooling device 24 is a cooling object a
And an up / down elevator 25 and a water tank 26 provided immediately below. 27 is an extraction table provided on the outlet side of the cooling device 24.

Therefore, the object to be heated a in the high-temperature heating furnace 2
Are on the transport rolls 3, 3, 3, ... and the transport rolls 4,
4, 4, ... supported in two stages and transported in the direction of the arrow,
While passing through the heating zones 2a to 2d, the swirling flow of the combustion flame is exposed in a different direction for each heating zone, and the heating flame can be uniformly heated to a predetermined quenching temperature (850 ° C.) in a short time. The object to be heated a extracted from the high-temperature heating furnace 2 is supported by the elevator 17 and immersed in quenching oil in an oil tank 18 to be rapidly cooled. The heat target a extracted from the oil tank 18 is transferred to the burn-off chamber 16 through the oil draining chamber 15 and burned by the combustion gas flow from the high-speed burners 9R and 9L to incinerate the quenched oil adhering thereto. Further, the object to be heated a is carried into the middle-temperature heating furnace 10, and is similarly supported and transported in two stages, while passing through the heating zones 10a to 10c.
The combustion flame blown out from 9L alternately exposes the swirling flow opposite to each other, so that the combustion gas flow hits the entire surface and is uniformly heated in a short time to a predetermined tempering temperature (400 to 600 ° C) and extracted on the elevator 25. Is done. When the elevator 25 moves downward, it is immersed in the cooling water of the water tank 26, cooled to near normal temperature, and discharged to the extraction table 27. Thus, a series of quenching and tempering processes can be completed.

The fan 23 is provided so that the cooling object can be air-cooled by blowing a cooling gas onto the heating object a extracted from the high-temperature heating furnace 2. It is used according to the processing purpose of (a). As described above, in this continuous heat treatment furnace, the high-temperature heating furnace 2 and the medium-temperature heating furnace 10 are provided in series, and the quenching device 13 and the cooling device 24 are provided at the extraction ports, respectively. Therefore, it can be applied to a wide range and has high versatility. In addition,
In this embodiment, an example is shown in which a transport roller is provided as a horizontal transport means. However, a mesh belt or another transport means may be provided.

[0015]

As described above, in the continuous heat treatment furnace of the present invention, a high temperature heating furnace and a medium temperature heating furnace are provided in series with a quenching device interposed therebetween, and each of them is provided with upper and lower two-stage horizontal transfer means. As a result, high throughput can be maintained without significantly increasing space and furnace wall surface area. Accordingly, the construction cost can be reduced, the heat loss can be reduced, energy can be saved, and the operation cost can be reduced.
And since it is versatile, there is an advantage that it can cope with heat treatment of various kinds. In addition, high-speed burners are arranged in a staggered manner so that the swirling flow of the oppositely facing combustion gas flow can be alternately applied to the object to be heated, so that the object to be heated can be uniformly heated in a short time to improve the quality. Has a beneficial effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a continuous heat treatment furnace according to the present invention.

FIG. 2 is a cross-sectional plan view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

[Explanation of symbols]

 a Heated object 2 High temperature heating furnace 2a to 2d Heating zone 3 Transport roll 4 Transport roll 6 Elevating table 8R, 8L Side wall 9L, 9R High-speed burner 10 Medium temperature heating furnace 10a to 10c Heating zone 13 Quenching device 14 Quenching room 15 Oil draining room 16 Burn-off room 17 Elevator 18 Oil tank 23 Fan 24 Cooling device 25 Elevator 26 Water tank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F27B 9/20 F27B 9/20

Claims (3)

[Claims] 1. A two-stage transfer type high-temperature heating furnace in which a horizontal transfer means is provided in a furnace in two upper and lower stages so as to be able to transfer an object to be heated in the furnace length direction in the upper and lower stages, respectively. As in the case of the temperature heating furnace, a two-stage conveyance type middle temperature heating furnace in which horizontal conveyance means are provided in two upper and lower stages, and a heating target provided in the loading port of the high temperature heating furnace and distributed to an upper stage or a lower stage. An elevating table, a quenching device provided between the high-temperature heating furnace and the medium-temperature heating furnace, for immersing a target object extracted from the high-temperature heating furnace in an oil bath, and extracting the medium-temperature heating furnace. A cooling device provided at a mouth for dipping the object to be heated extracted from the medium-temperature heating furnace into a water tank. 2. The continuous heat treatment furnace according to claim 1, wherein a fan is provided between the high temperature heating furnace and the medium temperature heating furnace to cool an object to be heated extracted from the high temperature heating furnace. . 3. In a continuous heat treatment furnace in which an object to be heated is conveyed in the furnace length direction, at least one pair of high-speed burners for blowing out a combustion flame at a high speed is provided on one side of the furnace body and on the other side of the furnace body. By providing a swirling flow of the combustion flame in the furnace by being opposed to the lower portion, the high-speed burners are arranged in the furnace lengthwise direction so that the object to be heated is conveyed as it is conveyed. A continuous heat treatment furnace characterized in that anti-swirl flows are alternately applied to a hot substance.