JP4146939B2 - Stainless steel strip continuous annealing furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous annealing furnace for stainless steel strips.
[0002]
[Prior art]
Conventionally, there are horizontal catenary type continuous annealing furnaces and vertical continuous annealing furnaces as continuous furnaces for continuously annealing stainless steel strips.
[0003]
[Problems to be solved by the invention]
However, in the former, the furnace is horizontally arranged, and a large number of support rolls are arranged in the furnace. And since these support rolls are water-cooled, heat loss is large, and the stainless steel strip comes into contact with many support rolls and is easily scratched. Also, the support rolls need to be replaced frequently, and maintenance is troublesome. There is a problem of being.
On the other hand, the latter furnace shape has an inverted U-shape, and the stainless steel belt carried from the lower tropical zone reaches the upper top roll chamber and changes its direction, and is extracted from the downward heating zone and reaches the cooling zone. Therefore, although there is no disadvantage of the former, not only the outside air enters from the bottom of the heating zone (extraction port) due to the draft effect of the heating zone, but also the furnace air in the final zone is likely to be disturbed, and the construction cost of the building because the furnace height is high However, there is a problem that the installation itself is expensive because a meander adjustment mechanism is required in the top roll chamber.
Therefore, an object of this invention is to provide the continuous annealing furnace of the stainless steel strip which can solve the said subject.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides
In a continuous annealing furnace of stainless steel strip consisting of pre-tropical zone, heating zone and cooling zone,
The pre-tropical zone and the cooling zone are horizontally arranged so that the former is at a high place, and the heating zone is inclined between the pre-tropical zone and the cooling zone so as to gradually descend toward the outlet side. as well as, the support roll the preheating home use port, the seam zone having a pressure pad between the heating zone and the cooling zone, also arranged a Hasurora the cooling zone, the stainless steel strip in the heating zone, said support rolls Are supported in a catenary state by a single pressure pad so that the lowest point is located on the outlet side of the heating zone, while being supported by the pressure pad and the heating zone side hearth roller of the cooling zone. .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
The stainless steel strip continuous annealing furnace T is generally composed of a pre-tropical zone A, a heating zone B, a joint zone C, and a cooling zone D.
[0006]
The pre-tropical zone A and the cooling zone D are arranged horizontally such that the former is higher than the latter.
In addition, the heating zone B is connected between the pre-tropical zone A and the cooling zone D so as to gradually descend toward the outlet, and a joint zone C is provided at the outlet of the heating zone B. It has been.
[0007]
A single support roll 1 is disposed at the exit of the pre-tropical zone A, an exhaust port 2 is provided in the hearth near the charging port, and exhaust gas is sucked from the exhaust port 2 by an exhaust gas fan 3. Exhausted. The exhaust gas passes through the heat exchanger 4 and preheats the combustion air of the direct fire burner 9 described below, and is then discharged from the chimney 5. In addition, 6 is a gas sealing device of the charging opening of the pre-tropical zone A, and 7 is a furnace pressure control valve.
[0008]
The heating zone B is partitioned into a plurality of partition zones by an upper partition wall 8a and a lower partition wall 8b, and each zone is predetermined by adjusting the amount of combustion of the direct fire burner 9 provided in each zone. The temperature rise pattern is obtained.
[0009]
In addition, 10 is a furnace pressure detector for controlling the furnace pressure control valve 7, and 11 is a radiation thermometer of the stainless steel strip W for controlling the combustion amount of the direct fire burner 9.
[0010]
In addition, the joint band C is provided with one known pressure pad 12 that buoys and supports the stainless steel band W by jetting gas upward and inward from each other, and an exhaust port 13 in the ceiling portion. It has. The stainless steel strip W forms a catenary state with the support roll 1 provided at the outlet of the pre-tropical zone A and the pressure pad 12 of the joint strip C. Reference numeral 14 denotes an opening adjusting door.
[0011]
A hearth roll 15 is disposed in the cooling zone D, and a known cooling means (not shown) is disposed.
[0012]
Next, an operation method of the continuous annealing furnace T will be described.
First, as shown in FIG. 1, a stainless steel strip (hereinafter referred to as a steel strip) W is passed through, and the exhaust gas fan 3, each direct fire burner 9, and the cooling means of the cooling zone D are driven to show each zone. The operation is started so that the heat curve shown in FIG. In this case, the steel strip W is preheated in the tropical zone A and radiantly heated by the exhaust gas flowing in from the heating zone B and preheated to about 200 ° C., and subsequently heated to about 1200 ° C. by the direct flame burner 9 in the heating zone B. Heated, cooled to about 80 ° C. by the cooling means in the cooling zone D, and annealed.
[0013]
The pressure pad 12 floats and supports the steel strip W and forms a catenary with the support roll 1 provided at the exit of the pre-tropical zone A. The arrangement position is the lowest point SAG of the catenary. Is on the outlet side of the heating zone B. As a result, the supporting load of the pressure pad 12 becomes a steel strip W between the lowest point SAG and the pressure pad 12 and between the pressure pad 12 and the hearth roll 15 up to the lowest point (not shown). The levitation force (gas ejection amount) can be small. In addition, since the pressure pad 12 is located on the cooling unit side outside the heating zone B, the ejection gas is relatively low temperature and has a high density, so that the driving power of the pressure pad 12 can be saved. Note that the joint band C may be divided and installed in the heating band B.
[0014]
【The invention's effect】
As is apparent from the above description, according to the present invention, the heating zone is configured such that the inlet portion is higher than the outlet portion and gradually descends toward the outlet portion, and the stainless steel strip is a pretropical outlet. The support roll provided in the section and one pressure pad provided in the joint band are transported in the catenary state, that is, in a non-contact state in the heating zone, and the stainless steel band is less damaged by the support roll and has a water-cooled structure. Because there is only one support roll, there is little heat loss. Further, since the heating zone is inclined, the space length required for installation is shorter than that of the horizontal furnace, and the furnace height can be set to about ¼ that of the vertical continuous annealing furnace.
[0015]
Further, in the heating zone, the exhaust gas rises due to the draft effect, but the height is low as described above, and the pretropical zone connected to the inlet of the heating furnace is horizontally arranged, so there is little draft effect, and the draft Based on the above, intrusion of cold air from the charging opening can be reduced, and the furnace temperature and the atmosphere in the furnace are not disturbed. Therefore, the gas sealing device is sufficient for the sealing device provided in the pre-tropical charging section.
[0016]
Furthermore, the support load of the pressure pad is the load of the stainless steel strip between the lowest point of the catenary generated in the heating zone and the pressure pad and between the lower limit point between the pressure pad and the cooling zone side hearth roll, The steel pad levitation force (gas ejection amount) of the pressure pad may be small, and the pressure pad is located on the cooling zone side, and the ejection gas is relatively low temperature and the density is high, so the driving power of the pressure pad is saved. It can be electric power.
[Brief description of the drawings]
FIG. 1 is a schematic view of a stainless steel strip continuous annealing furnace of the present invention.
FIG. 2 is a partially enlarged view of FIG.
[Fig. 3] Heat curve.
[Explanation of symbols]
A ... Pre-tropical zone, B ... Heating zone, C ... Joint zone, D ... Cooling zone, T ... Continuous annealing furnace, 1 ... Support roll, 2 ... Exhaust port, 8a, 8b ... Partition wall, 9 ... Direct fire burner, 12 ... pressure pad, 15 ... hearth roll, W ... stainless steel strip.

Claims (1)

In a continuous annealing furnace of stainless steel strip consisting of pre-tropical zone, heating zone and cooling zone,
The pre-tropical zone and the cooling zone are horizontally arranged so that the former is at a high place, and the heating zone is inclined between the pre-tropical zone and the cooling zone so as to gradually descend toward the outlet side. as well as, the support rolls to the preheating home use port, the seam zone having a pressure pad between the heating zone and the cooling zone, also arranged a Hasurora the cooling zone, the stainless steel strip in the heating zone, said support rolls And a single pressure pad that is supported in a catenary state so that the lowest point is located on the outlet side of the heating zone, while being supported and transported by the pressure pad and the heating zone side hearth roller of the cooling zone. A continuous annealing furnace for stainless steel strips.

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