Slab continuous casting average pulling speed calculation improvement method

Abstract

The invention discloses a slab continuous casting average pulling speed calculation improvement method. The method comprises the following steps that firstly, a display picture of average pulling speed data is added; step 2, firstly defining time intervals and starting time of white, middle and night classes; 3, a zero clearing program for recalculating the casting length at the beginning of each shift is manufactured; step 4, calculating the accumulated length of a speed encoder of the white shift 1 # pinch roll, but not calculating the simulation mode and the 100-meter acceleration process before casting; 5, calculating the accumulated time of white shift casting, and dividing the length by the time to obtain the average pulling speed of the white shift in the same simulation mode and the 100-meter speed increasing process before casting; and 6, the average pulling speed of the middle shift and the late shift is calculated in the same mode. The invention relates to the field of slab continuous casting, in particular to an improved slab continuous casting average pulling speed calculation method.

Description

Technical Field

[0001] The present invention relates to the field of slab continuous casting, and in particular to an improved method for calculating an average casting speed of a slab continuous casting. Background Art

[0002] A slab is a type of steel billet, formed by continuous casting molten steel in a continuous casting machine. Generally, a slab with a width-to-thickness ratio greater than 3 is called a slab. It is primarily used for rolling into sheet metal, but rolling has not yet begun. Typical slab sizes cast by continuous casting machines are 150-250mm thick and 1000-1800mm wide. Small slabs can be 600mm wide and 120mm thick. Slabs less than 100mm thick are called thin slabs.

[0003] Slab continuous casting is a continuous steelmaking and ironmaking technology that uses slabs as its primary product. Slabs with a width-to-thickness ratio greater than 3 are called slabs. Continuous slab casting is primarily used to produce flat plates (thick plates, medium plates, thin plates, and coils). Typical slab sizes cast by continuous casting machines range from 150 to 250 mm thick and 1000 to 1800 mm wide. Small slabs can be as wide as 600 mm and 120 mm thick. Slabs less than 100 mm thick are called thin slabs.

[0004] Due to the large width-to-thickness ratio of the slab, slab continuous casting is unique not only in terms of the structure of the continuous casting machine, but also in the production process. The structural characteristics of the slab continuous casting machine are mainly reflected in the secondary cooling zone and the straightening machine. Due to the large width of the slab, the billet entering the secondary cooling zone from the crystallizer has not yet fully solidified. Under the action of the static pressure of the molten steel, the billet is prone to bulging, causing increased resistance to pulling or even inability to pull out. Therefore, the billet guide and secondary cooling device must be densely arranged with guide rollers to control the bulging problem of the billet. The straightening machine also requires multiple rows of straightening rollers to pull out the billet. Modern continuous casting has a high pulling speed, and the billet entering the straightening machine has not yet fully solidified. In order to prevent the billet from bulging and reduce the deformation stress inside the billet during straightening, the straightening machine consists of more than 20 pairs of straightening rollers and is designed for multi-point straightening or continuous straightening. Due to the large width of the slab, the heat flux of the steel stream injected from the tundish is unevenly distributed within the mold, causing longitudinal cracks on the slab surface and rendering it scrapped. This was addressed by adopting a submerged nozzle and protected pouring process. Subsequently, to improve caster efficiency and slab quality and enable direct furnace charging for rolling, requirements were raised for increasing casting speeds and producing defect-free slabs. Consequently, slab continuous casting technology saw new developments, with the emergence of numerous new technologies and the formation of a comprehensive set of process technologies.

[0005] The casting speed of slab continuous casting is a crucial technical indicator in the continuous casting process, directly impacting key indicators such as production costs during the first milling and rolling process. Therefore, the average casting speed of each shift is the most critical metric for assessing the team's operational and scheduling capabilities. Previously, the average casting speed of each shift had to be calculated manually, which was unscientific, inaccurate, and subject to significant human interference. Summary of the Invention

[0006] The problem addressed by the present invention is that the average pulling speed of each shift needs to be manually counted, which is not very scientific and not very accurate, and there is a large human interference factor.

[0007] To solve the above problems, the present invention adopts the following technical solution: The present invention is an improved method for calculating the average casting speed of slab continuous casting, comprising the following steps:

[0008] Step 1: Add a display screen for average pulling speed data;

[0009] Step 2: Define the time intervals and start times for the three shifts: daytime, afternoon, and evening.

[0010] Step 3: Create a reset procedure to recalculate the casting length at the beginning of each shift;

[0011] Step 4: Calculate the accumulated length of the speed encoder of the 1# pinch roller during the day shift, but do not count the speed increase process during the simulation mode and the first 100 meters before casting;

[0012] Step 5: Calculate the accumulated casting time of the day shift. Similarly, the simulation mode and the 100-meter acceleration process before casting are not counted. Divide the length by the time to get the average casting speed of the day shift.

[0013] Step 6: Calculate the average pulling speed of the mid-shift and evening shifts in the same way.

[0014] The present invention achieves the following beneficial effects using the above-mentioned structure: A program is now built into the PLC program to calculate the average casting speed for each shift. The program is divided into three shifts: day, afternoon, and evening. The calculation begins at the beginning of each shift. The average casting speed for each shift is retained for 24 hours, reset after 24 hours, and recalculated, and displayed on the HMI. This ensures scientific and accurate calculations and reduces human interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A cross-sectional view of the display screen is added to step 1 proposed by the present invention;

[0016] Figure 2 This is the program setting diagram for step 2 proposed by the present invention;

[0017] Figure 3 This is the program setting diagram for step 2 proposed by the present invention;

[0018] Figure 4 This is a three-part program setting diagram for the steps proposed in the present invention;

[0019] Figure 5 This is a three-part program setting diagram for the steps proposed in the present invention;

[0020] Figure 6 This is a diagram of the four-part program setting for the steps proposed in the present invention;

[0021] Figure 7 This is a program setting diagram for step four proposed by the present invention. DETAILED DESCRIPTION

[0022] Example:

[0023] As the instruction manual Figures 1 to 7 As shown, the present invention is an improved method for calculating the average casting speed of slab continuous casting, comprising the following steps:

[0024] Step 1: Add the display screen of average pulling speed data;

[0025] Step 2: Define the time intervals and start times for the three shifts: daytime, afternoon, and evening.

[0026] Step 3: Create a reset procedure to recalculate the casting length at the beginning of each shift;

[0027] Step 4: Calculate the accumulated length of the speed encoder of the 1# pinch roller during the day shift, but do not count the speed increase process during the simulation mode and the first 100 meters before casting;

[0028] Step 5: The accumulated time of casting during the day shift, excluding the simulation mode and the 100-meter acceleration process before casting, is divided by the length to obtain the average casting speed of the day shift;

[0029] Step 6: Calculate the average pulling speed of the mid-shift and evening shifts in the same way.

[0030] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An improved method for calculating the average casting speed of slab continuous casting, characterized in that: The steps include: Step 1, adding a display screen of average pulling speed data; Step 2: Define the time intervals and start times for the three shifts: daytime, midday, and evening; Step 3: Create a reset procedure to recalculate the casting length at the beginning of each shift; Step 4: Calculate the accumulated length of the speed encoder of the 1# pinch roller in the day shift, but do not count the speed-up process in the simulation mode and the first 100 meters of casting; Step 5: Calculate the accumulated casting time of the day shift. Excluding the simulation mode and the 100-meter acceleration process before casting, divide the length by the time to get the average casting speed of the day shift. Step 6: Calculate the average pulling speed of the mid-shift and evening shifts in the same way.

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