JPH04254514A - Steel billet heating furnace - Google Patents

Abstract

PURPOSE:To enable heating of a cold billet, warm billet, hot billet, etc., to the necessary temp. without wastefulness in heating energy or in time, respectively, because the necessary system can be adopted and heated according to temp. of the steel billet, to make heat loss little at the time of shifting the steel billet to each heating chamber, and to reduce heat dispersion through furnace wall because surface area in the furnace is small. CONSTITUTION:Plural lines of parallel adjoining heating chamber A, B, C are partitioned with partitioned walls 2a, 2b in the furnace and in these heating chambers, conveying means 4a, 4b, 4c, by which the steel billets can be conveyed to the longitudinal direction, are arranged and also the opening parts 14, 15, 16, 17 penetrating the above partitioned walls 2a, 2b at an end part of each heating chamber are arranged, and by shifting the steel billet through this opening hole, the steel billet can be made to convey to only the necessary heating chamber according to the temp.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a heating furnace for continuously heating rolling steel pieces to a predetermined temperature.

0002

[Prior Art] Heating furnaces installed in rolling mills are used to heat steel slabs at room temperature (hereinafter referred to as cold slabs) and for heating high-temperature steel slabs that have just been cast (hereinafter referred to as hot slabs). There are various operating modes, such as heating a steel slab at an intermediate temperature (hereinafter referred to as a hot slab), or heating a mixture of these. In such a case, if the furnace length of the heating furnace is set to the length necessary for heating the cold pieces, redundant heating will inevitably be required for the hot pieces; on the other hand, setting the furnace length to a length suitable for the hot pieces Then, there is a problem that the cold piece cannot be heated to the required temperature.

[0003] Therefore, as a method to solve these problems, an intermediate charging type heating furnace was devised. In other words, a new hot piece charging inlet is installed in the side wall of the middle section where the temperature of the cold pieces being transferred in the furnace rises to a temperature range corresponding to the temperature range of the hot pieces being charged. This allows heating suitable for each to be performed efficiently in the same heating furnace.

Furthermore, as shown in JP-A-62-199715, a preheating furnace for preheating cold pieces and a heating furnace for heating cold pieces and hot pieces are arranged in parallel, and an extraction port is provided in the side wall of one end of the preheating furnace. At the same time, a charging port is provided on the side wall of the heating furnace at a position facing the extraction port, and the other side wall on the extraction port side of the preheating furnace or the heating furnace is provided so that the charging port and the extraction port are located in a straight line. A steel billet heating furnace is also being considered in which a charging port exclusively for hot flakes is provided on the other side wall on the charging port side.

[0005]

[Problems to be Solved by the Invention] However, in the case of the above-mentioned intermediate charging type heating furnace, it is difficult to provide a charging roll inside the furnace body at the charging port, and a large side charging machine such as a tong type crane is required. Since it is not possible to charge the heat strips without using a heat exchanger, the installation space becomes large, and the opening size of the charging port is also large, resulting in a problem that energy saving is not achieved. Another method is to suspend charging from the ceiling of the furnace body, but in this case, the sealing performance of the furnace becomes poor, resulting in large heat loss, and the charging machine becomes larger. In both cases, it is difficult to control the position of the hot charging pieces and to take heat-resistant measures for the charging machine, and there are problems such as low reliability of operation and equipment.

Furthermore, in the case of the billet heating furnace disclosed in JP-A-62-199715, since the two furnace bodies are arranged in parallel, the billet heating furnace is disposed between the preheating furnace outlet and the heating furnace charging port. could be exposed to the air outside the furnace, causing a drop in the temperature of the preheated steel billet, and at the same time, energy loss was likely to occur due to outflow of exhaust gas from the extraction port or charging port, intrusion of cold air, etc. In addition, since the entire furnace equipment is very long, it requires space and is difficult to install.

[0007]

[Means for Solving the Problems] The billet heating furnace of the present invention includes:
In order to solve the above problem, the inside of the furnace is divided into a plurality of parallel rows of heating chambers adjacent to each other by a partition wall, and the heating chambers are provided with a conveying means capable of conveying the steel pieces in the longitudinal direction. The main feature is that an opening passing through the partition wall is provided at the end of each heating chamber, and by transferring the steel billet through the opening, the steel billet can be transported only to the necessary heating chamber according to its temperature. shall be.

As a specific example, the inside of the furnace is partitioned by a partition wall into a hot-piece heating chamber, a hot-piece heating chamber, and a cold-piece heating chamber.

[0009] Further, the above-mentioned conveying means may include a walking beam,
Specific examples include a walking hearth or a pusher.

[0010] A heating method suitable for each steel piece can be selected according to its temperature, and there is no waste of thermal energy or time.

[0011]

Embodiments Next, the present invention will be explained in detail with reference to embodiments shown in FIGS. 1 and 2. FIG. 1 is a horizontal cross-sectional view of this steel billet heating furnace, and FIG. 2 is a cross-sectional view taken along the line A--A. Side wall 1a, 1
A furnace body 1 constructed in a substantially rectangular planar shape by b, 1c, and 1d has parallel partition walls 2a and 2b inside to form a hot-piece heating chamber A, a hot-piece heating chamber B, and a cold-piece heating chamber C. . Each heating chamber is provided with walking beam type conveyance means 4a, 4b, 4c consisting of a fixed beam 3 and a movable beam 4, and the steel pieces are conveyed in the longitudinal direction by driving the walking beam type conveyance means 4a, 4b, 4c. It is now possible to do so.

Reference numeral 5 denotes an opening for extracting steel pieces provided in the side wall 1a at the end of the hot piece heating chamber A, and the opening 5 can be closed at any time by an extraction door 6. 7 is an extraction roller table provided outside the opening 5. Reference numerals 8 and 9 are openings for charging steel pieces provided in the side wall 1 at both ends of the cold piece heating chamber C, and the openings 8 and 9 can be normally closed by charging doors 10 and 11, respectively. ing. 12 and 13 are charging roller tables provided outside the openings 8 and 9. Further, 14 and 15 are partition walls 2a at both ends of the hot piece heating chamber A.
an opening provided to penetrate through the openings 14 and 15;
As a result, the hot piece heating chamber A and the hot piece heating chamber B communicate with each other at both ends. Moreover, 16 and 17 are openings provided so as to penetrate the partition wall 2b at both ends of the hot piece heating chamber B, and the hot piece heating chamber B and the cold piece heating chamber C are connected to each other by the openings 16 and 17, respectively. communicate in the department. Note that the openings 14 and 15
, openings 16 and 17 are provided with a partition door 19 that is suspended from a cylinder 18 provided outside the furnace and moves up and down, as illustrated in FIG. Each opening 14, 15 and opening 16, 17 can be closed.

Reference numeral 20 denotes a transfer device which is installed on the side wall 1c of the furnace body 1 and transfers the steel pieces in the furnace in the width direction of the furnace.
0 indicates a plurality of rollers 2 that penetrate through the side wall 1c and project into the hot piece heating chamber A, the hot piece heating chamber B, and the cold piece heating chamber C, respectively.
2a, 22a..., 22b, 22b..., 22c, 22c...
Each roller is rotatably supported by a bearing 23 installed outside the furnace, and motors 24a, 2
It is configured to rotate by driving 4b and 24c. Further, reference numeral 25 denotes a transfer device that is provided on the other side wall 1d of the furnace body 1 and can similarly transfer the steel pieces in the furnace in the width direction of the furnace. A
A plurality of rollers 26a, 26a..., 26b, 26b..., 2 protrude into the hot piece heating chamber B and the cold piece heating chamber C, respectively.
6c, 26c..., each roller is rotatably supported by a bearing 27 installed outside the furnace, and motors 28a,
It is configured to rotate by driving 28b and 28c. Each of the heating chambers A, B, and C is provided with a heat source such as a burner, a radiant tube, an electric heater, etc., and the inside of each heating chamber is controlled to a required temperature that can raise the temperature of the steel piece.

In this billet heating furnace, when heating a cold billet now, the charging door 10 is opened and the cold billet on the charging table 12 is passed through the opening 8 into the rollers 22c and 2 in the cold billet heating chamber C.
2c...Move above. Then, by driving the movable beam 4 in the cold piece heating chamber C, the cold piece is conveyed in the longitudinal direction inside the cold piece heating chamber C as shown by the arrow, and the rollers 26c, 26c at the other end are transported.
...Transferred above. Then, the heated pieces heated by passing through the cold piece heating chamber C are heated to the opening 1 by rotating the rollers 26c, 26c... and the rollers 26b, 26b...
7 into the hot piece heating chamber B, and by rotating the movable beam 4 in the hot piece heating chamber B, the hot piece is further moved in the direction opposite to the cold piece heating chamber C as shown by the arrow. It is conveyed in the longitudinal direction of the direction and transferred onto the rollers 22b, 22b, . . . . While passing through the warm piece heating chamber B, the temperature of the hot piece further rises and becomes a hot piece, which is transferred onto the rollers 22b, 22b, . . . . And the hot pieces are rollers 22b, 22b..., roller 22a
, 22a, the hot piece is further carried into the hot piece heating chamber A through the opening 14.
It is further conveyed in the opposite longitudinal direction, heated to a required hot rolling temperature, and transferred onto rollers 26a, 26a...
By opening the extraction door 6, the liquid is extracted onto the roller table 7.

On the other hand, if the steel piece is still warm, such as when there is residual heat after casting steel, the hot piece is kept on standby on the roller table 13, the charging door 11 is opened, and the rollers 26b, 26b... , rollers 26c, 26c, . Then, it is transported in the longitudinal direction inside the hot piece heating chamber B as shown by the arrow, and then further transported to the hot piece heating chamber A in the same manner as above.
The hot rolling temperature is adjusted to the required hot rolling temperature and extracted through the opening 5.

Furthermore, when heating high-temperature hot pieces such as steel pieces after continuous casting, they are prepared on the charging table 12 in the same way as the cold pieces, and the rollers 22a, 22a, . . .
22b, 22b..., 22c, 22c... are rotated, and the hot piece is passed through the opening 8, the opening 16, and the opening 14 into the hot piece heating chamber A.
Transfer directly to Then, while being conveyed in the longitudinal direction within the hot piece heating chamber A, it is heated to a required rolling temperature and extracted from the opening 5.

Note that the partition wall 19 is always closed to prevent hot air from flowing between the heating chambers. In addition, this embodiment shows an example in which walking beam type conveyance means are provided in hot piece heating chamber A, hot piece heating chamber B, and cold piece heating chamber C, respectively. You may also use the formula. In addition, the steel pieces are heated in hot piece heating chamber A.
In addition to the above-mentioned roller type, a pusher type may also be used as a means for transferring from the hot piece heating chamber B to the cold piece heating chamber C from the hot piece heating chamber B.

On the other hand, FIG. 3 shows the arrangement of the exhaust gas duct provided on the ceiling of the furnace body 1. In this slab heating furnace, the duct 30 connects the end of the hot slab heating chamber A (the starting end of the slab conveyance), the end of the hot slab heating chamber B (the end of the conveyance of the slab), and the cold slab heating chamber. C is connected to the end of the hot piece heating chamber A (the end of conveying the steel piece) so that the high temperature exhaust gas in the hot piece heating chamber A can be supplied to the hot piece heating chamber B, and the hot piece heating chamber A is connected to the hot piece heating chamber A through the duct 31. The end of the cold piece heating chamber C is connected to the end of the cold piece heating chamber C (the end of the conveyance of the steel piece), and the end of the hot piece heating chamber B (the beginning of conveyance of the steel piece) is further connected to the cold piece through the duct 32. The end of the hot piece heating chamber C (the end of conveyance of the steel piece) is connected, and the high temperature exhaust gas in the hot piece heating chamber A is transferred to the hot piece heating chamber B.
Alternatively, the exhaust gas in the cold piece heating chamber C and the hot piece heating chamber B can be fed to the cold piece heating chamber C, respectively. By circulating the exhaust gas in this manner, the sensible heat of the exhaust gas can be effectively used for heating the steel billet. Furthermore, chimney 33
The heating chambers are connected to each other by ducts 34, 35, and 36, and exhaust can be directly exhausted from each heating chamber by passing through the ducts.

[0019]

Effects of the Invention As explained in the above embodiments, the steel billet heating furnace of the present invention is capable of heating the billet by selecting the necessary conveyance path according to the temperature of the billet, so that cold billet, hot billet, and hot billet heating furnace can heat the billet. Each piece can be heated to a required temperature without wasting thermal energy or time. In addition, since each heating chamber is separated by a partition wall and adjacent to each other, steel slabs can be transferred between heating chambers without the risk of outside air entering by simply passing through the opening in the partition wall, and the furnace body can be placed flat. Since it can be constructed in a substantially rectangular shape, it requires less installation space, and since the surface area of the furnace wall can be reduced, there is less heat dissipation through the furnace wall, which has a significant effect on energy saving.

[Brief explanation of the drawing]

FIG. 1 is a horizontal sectional view of a billet heating furnace showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1.

FIG. 3 is a plan view of the furnace body showing the arrangement of the exhaust duct.

[Explanation of symbols]

Claims (6)

[Claims] Claim 1: The inside of the furnace is divided into a plurality of parallel rows of heating chambers adjacent to each other by a partition wall, and the heating chambers are provided with conveying means capable of conveying the steel pieces in the longitudinal direction. A steel billet heating furnace characterized in that an opening is provided at an end of the partition wall and passes through the partition wall, and the billet is transferred through the opening so that the billet is transferred only to a necessary heating chamber according to its temperature. 2. The steel billet heating furnace according to claim 1, wherein the inside of the furnace is partitioned into a hot flake heating chamber, a hot flake heating chamber, and a cold flake heating chamber by a partition wall. 3. The steel billet heating furnace according to claim 1, wherein the conveying means is a walking beam, a walking hearth, or a pusher. 4. A steel billet heating furnace according to claim 1, wherein the means for transferring the steel billet through the opening is a roller. 5. The steel billet heating furnace according to claim 1, wherein the opening is provided with a partition door. 6. The steel billet heating furnace according to claim 2, wherein one end of the cold flake heating chamber is provided with an opening for charging both cold and hot flakes, and the other end is provided with an opening for charging hot flakes. .