JPS6118028Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to catenary continuous annealing furnace equipment used in the annealing and pickling process of stainless steel strip.

In general, stainless steel strips are strictly required to maintain a good surface condition, so asbestos rolls are used as support rollers because they are less susceptible to scale pick-up (or build-up) and are softer than the strips.

However, since this asbestos roll has low heat resistance (normally 700℃ to 800℃, special materials have a heat resistance of about 1000℃), the furnace atmosphere temperature (1200℃ to
It is impossible to install it in a furnace at a temperature of 1300℃.
A space must be provided between each furnace, and the furnace must be installed in a location where the temperature is low. For this reason, the strip is cooled in this space, which becomes a major obstacle to improving the thermal efficiency of the equipment, and the surface oxidation of the strip becomes excessive, making it necessary to increase the capacity of the descaling device installed on the outlet side of the furnace. It didn't happen.

In addition, since this asbestos roll is extremely soft compared to the strip, it is subject to severe abrasion due to the passing of the strip, and the surface must be polished every 7 to 8 hours on average, resulting in a short roll life and low maintenance and running costs. This is a major negative factor.

The present invention aims to solve the conventional problems as mentioned above.

That is, the present invention connects multiple catenary furnaces,
The present invention is characterized in that a water-cooled steel roll is provided directly in a catenary furnace, and continuous annealing is performed in the furnace while forming a plurality of catenaries on the strip conveyed by the steel roll.

In this way, by using direct water-cooled steel rolls that do not cause scale pick-up (or build-up) in a very short time like ordinary heat-resistant steel rolls, we are able to prevent scratches on the strip surface. It became possible to perform heat treatment without any occurrence. As a result, the frequency of roll maintenance has been dramatically reduced, and since there is almost no wear, the same roll can be used repeatedly for long periods of time simply by polishing the roll surface, significantly reducing equipment costs and running costs. I was able to measure it. As an example of the use of this direct water-cooled steel roll, conventional asbestos rolls had a polishing cycle of about 7 to 8 hours and a roll life of about 1 to 2 months, but with this roll, the polishing cycle was about 3 weeks to 1 month. months, roll life is 1
It has been confirmed that it is more than 2 years old.

In this way, in this invention, the direct water-cooled steel roll placed inside the catenary furnace can be used at ambient temperatures of up to 1300°C, and moreover, multiple catenaries can be connected using a closed throat. By doing so, maintenance of the direct water-cooled steel roll can be facilitated. In other words, by connecting catenary furnaces with closed throats, the throat internal temperature can be lowered by 100 degrees lower than the ambient temperature inside the furnace body (approximately 1250°C to 1300°C MAX).
Since it is possible to lower the temperature by approximately 200°C,
The lifespan of direct water-cooled rolls can be dramatically increased compared to when they are placed inside the furnace body. In this way, in this invention, by using a direct water-cooled steel roll in the catenary furnace, cooling of the strip can be prevented, and the negative thermal efficiency caused by using a direct water-cooled steel roll can be sufficiently compensated for. Thermal efficiency has been increased, and significant effects have been achieved in terms of energy conservation.

If a direct water-cooled steel roll is used as described above, it can be used continuously for a considerably longer period than before, but scale pick-up (or build-up) may occur during long-term use. Yes, at this time remove the roll and perform polishing. The line will be suspended for this roll replacement work.
The horizontal drawing method is common, but it is also possible to rearrange the rolls from the lower part of the throat in order to eliminate losses due to line stoppages.

One embodiment will be described below with reference to the drawings.
FIG. 1 is an overall schematic diagram of the present invention, in which a strip 1 is conveyed through an annealing furnace 2 and a throat 4 by support rollers 5 (directly water-cooled steel rolls), heated by a burner 6 provided on the furnace side wall, and heated.
After being heat-treated, the exhaust gas is discharged to the outside of the furnace through the flue 3. In addition, the furnace pressure is controlled by installing a furnace pressure adjustment damper in the middle of this flue.
It is also possible to prevent air from entering the furnace and increase thermal firing efficiency.

FIG. 2 is a schematic diagram of the throat section between the furnaces;
A throat 4 is provided between the annealing furnaces 2, and a support roll 5 is fixed to the side wall of the throat by bearings 9.

Figure 3 is a schematic diagram of a standard direct water-cooled steel roll used in this invention.As shown in this figure, cooling water is generally supplied in one direction and drained from the other. However, water is supplied from the same location,
It is also possible to carry out drainage. Reference numeral 5 denotes a roll body, which ensures rotation of the roll by a rotary joint 7, and uses a flexible hose 8 to provide one-touch piping connection. 9
indicates a bearing.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram of the present invention, FIG. 2 is a schematic diagram of the throat section provided between the furnaces of the present invention, and FIG. 3 is a schematic diagram of an example of the direct water-cooled steel roll of the present invention. 1... Strip, 2... Annealing furnace, 3... Flue, 4... Throat, 5... Support roll (direct water-cooled steel roll), 6... Burner, 7...
Rotary joint, 8...flexible hose, 9...bearing.

Claims (1)

[Scope of utility model registration request] Multiple catenary furnaces are connected by a throat,
Continuous annealing furnace equipment for stainless steel strip, characterized by a water-cooled steel roll installed directly inside the throat.