RU2480298C1 - Heat-insulating shield of mill for wide beam (rail) rolling - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: heat-keeping unit comprises several sections, each including bearing housing with shielding panels secured thereto. Said shielding panels are composed of a set of rectangular tubes filled with heat insulator. Decrease in temperature drop across rolled stock cross-section is ensured by making panel width equal, at least, the width of said rectangular tube. Note here that said bearing housing is linked with drive of horizontal displacement to/from roll-table. Note also that linkage supports said drive. Besides, said section is equipped with detachable lateral heat-reflection panels.

EFFECT: higher quality of long beams and rails (up to 100-150 m-long).

2 cl, 4 dwg

Description

The invention relates to ferrous metallurgy.

In recent years, there has been a tendency to roll wide-shelf beams (and rails) of increased length: up to 100 ... 120 m, and even 150 m.

With such a length of the roll, especially in the last aisles and especially in the thinnest places of the cross section, there is an increased unacceptable cooling of the roll, uneven along its length. Since the noted phenomenon is most manifested in the last pass of rolling, the latter reduces the quality of the finished product.

A set of similar technological problems in the iron and steel industry in the production of strips on broadband hot rolling mills is solved by heat-insulating shielding of the roll on the mill line, where these losses are maximum: on the intermediate rolling table of the mill. In industry, heat storage screens (TAE) are most widely used.

However, the heat-insulating shielding of the roll has not yet found application on high-quality mills, which is especially negatively manifested on these mills when rolling long (over 100 m) wide beams and rails.

This technical proposal addresses this drawback of mills for rolling wide beams and rails.

Known heat-insulating rolling table of a rolling mill, made in the form of a series of sections installed above the rolling table of the mill, each section containing a supporting structure and shielding panels mounted on it (see, for example, patent No. 1519799, Russia, B21B 1/26).

The specificity of the rolling technology of wide beams and rails with their, in some cases, reversible passages and moving the roll between the passages across the pitch field makes it difficult to directly use the known heat-insulating screen, requires certain technical solutions to improve the performance of heat-insulating shielding.

The proposed heat-insulating screen of the mill for rolling wide beams and rails contains a number of sections mounted above the roller table, each section containing a supporting body and shielding panels mounted on it made of rectangular pipes filled with a heat insulator, according to the proposal, the panel width is at least equal to the width specified a rectangular pipe, while the bearing housing is connected by means of rods to a stationary mounted horizontal drive of the section moving to / from the roller table, and these rods are installed The drive for turning the section to / from the roller table is inserted. In addition, the side walls of the load-bearing housing facing the rolling table are made with removable heat-reflecting plates.

The proposed heat-insulating screen of the mill for rolling wide beams (rails) is illustrated by schematic drawings in figures 1-4.

Figure 1 shows the arrangement of sections of the heat-insulating screen relative to the roll and rolling stand in the last pass; figure 2 - the main elements of the cross-sectional structure of the section; figure 3 and 4 - the provided movement of the section to / from the roller table and the rotation of the section to / from the roller table and the mechanisms for their implementation.

The heat-insulating screen of the mill for rolling wide beams (rails) contains (Fig. 1): 1 - rolling mill (when reversing rolling, the mill can contain one mill with a set of calibers along the length of the roll barrel), in which the last pass is carried out, while rolling 2 get the finished product 3 (wide beam or rail). Roll 2 rests on the drive rollers 4 of the roller table. On top of the workpiece 2, a number of sections of heat-insulating screens are installed 5. At the bottom of the roll 2, between the rollers 4 of the roller table there are inter-roller plates 6 (FIGS. 1 and 2) having containers along their length (in the direction of hire) filled with air mill scale 7. The inter-roller plate is made according to at least two containers, while in the direction of movement of the roll 2, said containers are placed in staggered order on the inter-roller plates. Each section has a supporting body 8 (figure 2). On the housing 8, with the help of suspensions 9, rectangular pipes 10 are suspended, filled with a heat insulator 11. The heat insulator 11 is also located between the set of these pipes 10 and the supporting body 8.

Rectangular tubes 10 are arranged in length in the rolling direction of the workpiece 2. The tubes 10 are pulled together by the rod 12. When rolling on a mill of relatively small width products (for example, R50 rails, see the dotted line in FIG. 2), the section is composed of one rectangular tube 10 located in the middle section and suspended by means of suspensions 9 as shown in figure 2, for the central pipe, while the suspension of the pipes 10 is made through the rods 12. The angles of the cross sections of the rectangular pipes 10 facing the workpiece 2 are made in the form of piano loops 13, which except chaet formation of fatigue cracks. An integral part of the section are heat-reflecting plates 14 made of a steel sheet coated with aluminum (the coating is carried out by thermal spraying). Plates 15 limit the space of the roller table in which rolling can move in the transverse direction.

All sections 5 are equipped with mechanisms for their movement (FIGS. 3 and 4) to / from the roller table: linear and by rotation. For linear movement, each section is equipped with wheels 16, rods 17 and a hydraulic cylinder 18 (Fig.2-4). To rotate the section to / from the roller table, each section is equipped with supports 19 (Figs. 2-4), pivotally connected through rods 20 to cylinder 21. In turn, cylinder 21 is rotatably mounted on rod 17. Wheels 16 move along guides 22 of the flooring of the workshop , providing movement of the sections on the deck 22 perpendicular to the rolling table of the mill. The locking sections 5 is strictly above the roller table (Fig.2 and 3). The latter is ensured by the presence of corresponding stops on the flooring 22 and on the draft 17 (this is not considered here, since it does not present technical complexity).

Thermal insulation screen works as follows.

At the rolling mill (Fig. 1), at the last pass, from the roll 2 in the rolling stand 1, finished rolled products 3 (wide-shelf beam or rail) of increased length (for example, more than 100 m) are obtained. Due to the long stay of the roll 2 in front of the stand 1, the roll is cooled more lengthwise (temperature wedge), and there is an uneven temperature distribution over the resulting roll section due to the different thicknesses of its walls. In total, the above makes it difficult to obtain high-quality finished products 3.

To reduce the noted negative phenomenon, the roll 2 is insulated from the environment: from the top by sections 5, from below by the air scale 7 in the capacities of the inter-roller plates 6. The capacities in the inter-roller plates are arranged in a checkerboard pattern during rolling, which eliminates the jamming of the side walls of the front end of the roll in these capacities.

Figure 2 shows the placement of the roll 2 on the rollers of the roller table 4 when passing between the plates 15, forming with the rollers 4 interroller space. The same figure marks the shielding of the roll below the air scale 7.

On top of the roll, heat-insulating sections 5 are located, each of which contains (Fig. 2) a supporting body 8 (formed from a sheet of mild steel), in which rectangular plates 10 are fixed on the suspensions 9, a set of which are pulled together by rods 12, forming a panel. To reduce the effect of linear thermal expansion of pipes 8 on the operation of heat-shielding sections, the length of the pipes in the panel in the rolling direction is about 490 ... 900 mm, and with a length of about 490 mm, the section is equipped with two panels with a gap between them of about 10 mm. The length of section 5 can reach 3.0 ... 4.0 m, with a corresponding increase in the number of panels, but not their length; the use of long section lengths is undesirable since When working, problems arise with the longitudinal stability of the section.

Pipes 10 are filled with one and a half times seal of heat-insulating mulite-siliceous wool 11. In the space between the set of pipes 10 and the supporting body 8, mulite-siliceous wool in the form of plates is also located. Side plates 14, made of a sheet of mild steel, on the side of the roll 2 are sprayed with a thickness of 0.15 ... 0.3 mm aluminum; spraying is performed in a gas-thermal manner; the degree of blackness of the coating ranges from 0.2 to 0.35. In the work of the section, a kick of roll 2 is allowed on plates 14 s / their bend (see 14 ').

In the process of rolling the roll 2 sections 5 occupy the working position (Fig.1-3). To feed the next roll 2 to the roller table 4 (during reverse rolling), the sections are turned from the roller table relative to the axis of the roller 16 using the cylinder 21, rods 20 and due to the articulated joint 19 (figure 3). After feeding the roll 2 to the roller table 4, the section is rotated to the roller table, i.e. in reverse order.

Section 5 is also provided for withdrawal from the roller table (FIG. 4), including with the already described rotation (FIG. 3) of the section. The need for this operation arises when installing in the section of the set of new pipes 10, heat insulator 11 and plates 14. At the end of these works, cylinders 18 and rods 17 are used, which are connected to the bearing case of section 5, which allows rolling the wheels 16 to return the cartridges 5 to working position over the rolling table.

Thus, the implementation of this technical solution significantly improves the temperature conditions for rolling long-length wide-shelving beams and rails in the last pass, thereby improving the quality of finished products.

Claims (2)

1. The heat-insulating screen of the mill for rolling wide beams and rails, containing a number of sections mounted above the roller table, each section containing a supporting body and shielding panels fixed to it, made of rectangular pipes filled with a heat insulator, characterized in that the panel width is at least the measure is equal to the width of the specified rectangular pipe, while the bearing housing is connected by means of rods to a stationary drive of horizontal movement of the section to the live roll or from the live roll, and on these rods tanovlen rotation drive section to the roller conveyor or roller conveyor. 2. The heat-insulating screen according to claim 1, characterized in that the side walls of the load-bearing housing facing the rolling table are made with removable heat-reflecting plates.

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