JPS61204312A - Method for determining extraction schedule of ingot or the like in continuous heating furnace - Google Patents

Abstract

PURPOSE:To determine exactly the extraction schedule of ingots by predicting the charging pitch of the succeeding ingots to be charged into a heating furnace in the stage of extracting the preceding ingots from the furnace at the point of the time when the preceding ingots are charged into the furnace and determing the intended extraction time of the preceding ingots. CONSTITUTION:The ingots 1 from a continuous casting machine are directly fed to the heating furnace 2. The ingots are charged into the furnace through a charging port 2a and are extracted through an extraction port 2b. The extracted ingots are fed in a heated state to a rolling installation. The extraction pitch of the ingot 1i is determined by taking the charging pitch of the ingot 1j to be charged into the furnace 2 when the charged ingot 1i is going to be ejected from the furnace 2 into consideration in the stage of charging the ingot 1i into the furnace 2. The pitch is determined by the pitch for restricting the heating with the charging ingot 1i and the pitch, etc., of a rolling installation in a downstream stage.

Description

[Detailed description of the invention] <Object of the invention> Industrial field of application The present invention relates to a method for determining the extraction schedule for steel billets, etc. in a continuous heating furnace. The present invention relates to a determination method capable of determining the scheduled extraction time of a steel billet or the like from a continuous heating furnace in consideration of fluctuations in the conveyance pitch in upstream equipment such as continuous casting equipment.

Conventional technology In general, in the heating operation of a continuous heating furnace, it is necessary to accurately predict the scheduled extraction time of the steel billet, etc., which is the material to be heated, when it is charged into the furnace, that is, to determine the extraction schedule. The determination has extremely important meaning in terms of the quality of the steel billet and in satisfying objectives such as achieving energy conservation. The conventional basic method for determining the extraction schedule is that when the rolling capacity is greater than the heating capacity, the extraction schedule is determined by the heating pitch, and when the heating capacity is greater than the rolling capacity, the extraction schedule is determined by the rolling pitch. In either case, the heating furnace and equipment downstream of the heating furnace (
For example, it is determined by the constraints of the facilities (for example, the facilities in charge).

This is based on the premise that there is generally a steel material buffer yard in front of the heating furnace, and the steel material supply capacity to the heating furnace is always greater than the heating capacity and rolling capacity.

However, in recent years, from the standpoint of energy saving and rationalization, various equipment in the upstream process of the heating furnace, such as a continuous casting machine, are directly connected to the continuous heating furnace via conveyance equipment, in an effort to make them continuous and synchronized. In this way, Ren 11tM! 1. When the heating furnace and rolling mill are directly connected as one line, the steel supply capacity from continuous casting is not necessarily greater than that from heating and rolling, and in such cases, the steel supply pitch from continuous casting is adjusted to match the steel supply pitch from continuous casting. Heating is more advantageous in terms of unit consumption. In such a heating operation, according to the conventional method described above, in which the extraction schedule is determined by considering only the downstream process equipment after the heating furnace and its capacity constraints, Pitch fluctuations in upstream processes such as suspension of charging of steel billets and overflow are not taken into account at all, and this causes a problem in that it is difficult to accurately determine an extraction schedule.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned problems.Specifically, slabs etc. from a continuous casting machine are directly conveyed to a continuous heating furnace by conveyance equipment, and the continuous heating is carried out due to the capacity balance of each equipment. When performing heating operations at the steel supply pitch from casting, when determining the extraction schedule for steel slabs, etc. in this continuous heating furnace, the extraction schedule should be determined by taking into account the equipment and capacity constraints of the upstream process of the heating furnace. It provides a method for making decisions.

<Structure of the Invention> Means for solving the problem and its operation, that is, the method of the present invention is such that when a steel billet, etc. is charged into a continuous heating furnace, heated, and then extracted, one steel billet, etc. is heated. At the time of charging into the furnace, when one charged steel billet, etc. is heated and extracted, other steel billets, etc. to be charged to the heating furnace are determined, and other steel billets, etc. The method is characterized in that the charging pitch of the charged steel billet, etc. is predicted, and the scheduled extraction time of the one billet, etc. is determined based on the predicted charging pitch of the other billet, etc.

Further, the configuration and operation of this means will be specifically explained with reference to the drawings as follows.

First, as shown in Fig. 1 (a), a steel billet 1 is directly sent from a continuous casting machine (not shown) to a heating furnace 2, the steel billet 1 enters from a charging port 2a, is extracted from an extraction port 2b, and is heated. The steel billet 11 is sent to a rolling facility (not shown) in this state.
is charged into the furnace 2 as shown in FIG. 1(a), this charged billet 11 is charged into the furnace when this billet 11 is extracted as shown in FIG. 1(b). The extraction pitch is determined in consideration of the charging pitch of the steel slabs 1j. That is, as shown in FIG. 1(a), before determining the extraction pitch of the steel billet 11 currently charged into the heating furnace 2, first, the charged steel billet 11 is moved through the heating furnace 2. Anticipate when the steel billet 1J will pass through and be extracted from the extraction port 2b, determine another steel billet 1j to be charged into the heating furnace 2 at this time, and by determining this other steel billet 1j, The extraction pitch of the charged steel billets 11 is determined by the charging pitch into the furnace. In this case, due to a temporary suspension of charging, etc., there may be no actual steel billet in the location corresponding to another steel billet 1j, and in this case, as in the conventional example, the charged steel billet It is sufficient to determine the heating restriction pitch for No. 11, the pitch of rolling equipment in the downstream process, etc.

Therefore, the method for determining the mouth will be explained in more detail as follows.

1) When W4 pieces are continuously charged into the heating furnace and the charging is not stopped midway, in this case, as shown in Fig. 2, one steel piece 11 is charged into the long-length heating furnace 2. At the time of charging, the upstream side of the charged billet 11 is searched based on the production plan information of the upstream process or the charging plan information into the heating furnace 2. At this time, the first steel piece (for example, the Xth piece) that satisfies the following equation (1) is defined as another steel piece 1j.

≦ Σ (blind +Δlk)... (1) is Hatake Ikai 1 However, [; Length of heating furnace, Wk: Width occupied by one piece 1 in the longitudinal direction of the furnace, 8Wk:
The other billet 1j determined as described above, with a spacing in the furnace of -1 between billet 1 and billet 1, is charged into the furnace at the time when billet 11 is extracted from the furnace.

Next, the extraction pitch of the charging billet 11 from the furnace is as follows (2)
Determined by the formula.

PITCH (i) = PCC (j) (2)
However, plTctlm: Extraction pitch of charged billet 11, PCC(j): Charge pitch of billet 1J into the furnace (production pitch of billet 1j in the upstream process) 2) Upstream from billet 11 as above If charging to the heating furnace is stopped during the process of searching to the side, first, as shown in Figs. 3 and 4, the charged steel billet 11
Then, the steel billet corresponding to the steel billet immediately before the charging to the heating furnace 2 is stopped is designated as the steel billet 1n. Furthermore, if the length occupied in the longitudinal direction of the furnace by the group of steel slabs extracted from the heating furnace 2 before charging is stopped is 11, then this l is the following (3
) is obtained by the formula.

1, = Σ(Wk+ΔWk)...(3)K-
i is medium, but l, < L.

Therefore, to determine the steel billet 1J, the following steps (a), (
This is done separately in case b).

(a) If the charging stop ends before the charged billet 11 is extracted, that is, if a billet ir-, is found that satisfies the following equations (4) and (5), (4) ), find the steel piece 1M for the minimum M that satisfies equation (5) (see Figure 3).

TStOD≦Σ [PITCll(k) + TKY
US(k) ]・・・・・・(4) 11111141 M≦MO・・・・・・・・・・・・・・・・−
・・・・・・・・・・・・・・・・・・(5) However,
'rstop: Charging stop time, PITCH(k):
Extraction pitch E seconds/piece for steel slab 1], YUS (k) for ■
: Extraction pause time [seconds] until steel billet 1K is extracted after steel billet 1 to 1 extraction, IIl: Last steel billet 1m extracted before charging is stopped, M:
The final billet 1M to be extracted during the charging stop.At this time, if the length occupied in the furnace of the steel billet extracted from the furnace during the charging stop is 12, however, if the charging stop time Tstop is 11Tl, then If the time is shorter than the time it takes for steel piece 1rrl+ to be extracted after being extracted, then (Tstop<PITCH(n++1)+
Let T be YUS(Ill+1), 12=O...(7). Then, if 13-L /+ 12... (8) and the first billet to be charged after stopping charging is billet 1P, the upstream side of billet 1P is searched and the next ( 8'), the first X-th one that satisfies formula (8'') is determined as another steel billet 1j in the same manner as above, and the extraction pitch of the charged steel billet 11 is determined.

13≦Σ(Wk+ΔWk)−・・・(8′ 1 to 1ρ However, Δwp−.

PITC former N-FCC(j)・・・・・・(8-)(b
) As shown in FIG. 4, when the charged steel billet 11 is extracted during the charging stop, that is, when there is no other steel billet 1j to be charged into the furnace at the time of extraction of the charged steel billet 11, At this time, rstop > Σ(PITCH(k) + Ytl
S(k)) --- (9) is established, and the extraction pitch at this time does not need to take into account the upstream conditions as described above. It is determined in consideration of the heating restriction pitch [seconds/piece] of No. 11, the restriction pitch [seconds/piece] of rolling, etc., the standard extraction pitch, etc.

As mentioned above, among the information used when determining the extraction pitch by the method of the present invention, the width of the steel billet (Wk), the billet charging interval (ΔWk), and the charging pitch of another 1J of steel billets (PCC (j)
), extraction stop time for billet 1 (TKYUS (+01), furnace charging stop time (Tstop) is determined from the future operation schedule, and is information obtained in advance as production plan information. .

Example Next, an embodiment will be described with reference to FIG.

First, FIG. 5 is a flow sheet of an example of an apparatus for carrying out the method of the present invention, in which continuously cast steel slabs, which are cast based on the production control computer 13 in a continuous casting factory indicated by reference numeral 6, are cut and rolled at a rolling factory. The heating furnace 9 is transported by a transport facility 10 to the heating furnace 9 of No. 7, and this heating furnace 9 operates synchronously and continuously with the continuous casting machine 8. The production management computer 12 of the rolling mill 7 receives the production plan and production plan change information 4 from the production management computer 1 of the continuous casting factory 6.
Based on this, information on plans such as the width of billets to be charged into the furnace in the future, billet charging pitch, extraction suspension, charging suspension, etc. is sent to the computer 3, which performs calculations for the heating furnace extraction schedule and heating furnace combustion control. 5 can be conveyed.

This calculator 3 determines the extraction schedule for the charged billets, that is, the schedule for movement within the furnace, at the time of charging the billet, as described above, based on the information 5, the length of the heating furnace, the interval between the billet billets, etc.

Based on the determined extraction schedule, the computer 3 satisfies the heating constraints on the quality of the billet and performs combustion control to achieve this goal, thereby achieving optimal operation by synchronizing the continuous caster and the heating furnace. can be done. Incidentally, the heated steel billet is rolled in the rolling equipment 11.

<Effects of the Invention> As explained in detail above, the method of the present invention enables charging of one of the steel billets directly from the continuous casting equipment, etc. at the time when one of the billets is charged into the continuous heating furnace. Determine the other billets to be charged into the furnace when a billet is extracted, and schedule the extraction of the previous billet based on the charging pitch of the other billets. This is what determines the Therefore, when the heating and rolling capacity exceeds the material supply capacity of continuous casting, the extraction schedule can be determined accurately when the continuous heating furnace is operated in synchronization with the upstream continuous casting equipment, and the quality of the billet is improved. heating constraints can be fully satisfied, and energy savings can also be achieved sufficiently.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are explanatory diagrams showing the time when one steel billet is charged into the heating furnace and the other steel billets that are charged into the heating furnace at the time of extraction, and Figure 2 3 is an explanatory diagram of an example of a method for searching for a steel billet extracted when charging a single billet, FIG. 3 is an explanatory diagram of a method similar to FIG. The figure is an explanatory view of a case where the charging of other steel pieces is stopped and there is no other steel piece when one steel piece is extracted, and FIG. 5 is a 70-sheet diagram of an example of an apparatus for carrying out the method of the present invention. Code 1... Steel piece

Claims (1)

[Claims] When charging steel billets, etc. into a continuous heating furnace, heating them, and then extracting them, when one steel billet, etc. is charged into the heating furnace, that one charged steel billet, etc. is heated and extracted. At the same time as determining the other steel billets, etc. that should be charged into the heating furnace, the charging pitch of the other steel billets, etc. is predicted, and based on this predicted charging pitch of the other steel billets, etc. , a method for determining an extraction schedule for steel billets, etc. in a continuous heating furnace, characterized by determining a scheduled extraction time for said one charged steel billet, etc.