A control method for setting up a rolling mill gap safety protection and a rolling line

Abstract

The application discloses a control method for setting up a rolling mill roll gap safety protection and a rolling line. The rolling line PLC receives a model vertical roll gap setting of an upper computer, combines actual width data of a rolled steel plate measured by a rough rolling mill side guide plate, and takes the actual width data as a vertical roll gap logical setting. Through collection of a hot metal detector signal, a roll gap setting logic and an error proofing protection control are re-established. The application avoids the occurrence of defects in the prior art, increases hourly productivity, reduces energy consumption loss during abnormal shutdown, and lowers equipment maintenance cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the automatic control technology of wide and thick plate vertical roll mill, more particularly to a control method for setting the roll gap safety protection of the mill and a rolling line. BACKGROUND

[0002] In combination Figure 1 As shown in the figure, the existing 5m thick plate vertical roll mill 1 is arranged in the area between the descaling box 2 and the roughing mill 3 in the production process site, and the vertical roll mill 1 is mainly used for solving the plane shape problem of the steel plate in the steel plate spreading stage of the roughing mill 3 and the finishing stage of the finishing mill 4, and effectively improves the steel plate yield. In combination Figure 2 As shown in the figure, the vertical roll mill mainly works through the combined action of the screw rod driven mechanical press-down (EWC), the working roll balance and the hydraulic press-down (HGC), and the roll gap position is set according to the steel plate information.

[0003] However, in the actual production, the accident of the steel plate being extruded and arched by the vertical roll mill and entering the descaling header between the roughing mill and the vertical roll mill occurs when the steel plate is empty in the last pass of the roughing mill and is rolled in the vertical roll mill.

[0004] According to the analysis of the on-site video and PDA data, the preliminary cause is judged as follows:

[0005] 1. The vertical roll gap is set too small, which leads to the arching of the head of the steel plate and is the direct cause of the accident;

[0006] 2. The vertical roll gap is set to the maximum value of the width of the roughing mill side guide plate centering and the model calculation width. The communication between L1 and L2 is abnormal, which leads to the use of the width of the last steel plate in the calculation of the theoretical width. At the same time, the roll gap setting logic and the error protection control are not perfect, which leads to the setting of the vertical roll gap being too small and is the root cause of the accident.

[0007] According to the analysis of the record data of the data acquisition system, the thickness of the steel plate during rolling is 92mm, and the calculation width is 2567mm. When the accident occurs, the vertical roll mill sets the roll gap to 2330mm, which is 237mm narrower than the width of the steel plate. The excessive vertical roll mill press-down amount leads to the arching of the steel plate, and finally the steel plate enters the descaling header between the vertical roll mill and the roughing mill. The steel plate with a temperature of 900 degrees must be cooled to about 40 degrees before cutting, and the surrounding damaged steel plate must be recovered. The whole process takes about 7 hours at the fastest, which is time-consuming and labor-intensive, and seriously affects the rolling line capacity and the energy consumption of the furnace. At the same time, it also increases the equipment repair cost. SUMMARY

[0008] In view of the above defects in the prior art, the purpose of the present application is to provide a control method for setting the roll gap safety protection of the mill and a rolling line, to avoid the occurrence of the defects in the prior art, to increase the hourly capacity, to reduce the energy loss during abnormal shutdown, and to reduce the equipment maintenance cost.

[0009] To achieve the above object, the present application adopts the following technical solutions:

[0010] In one aspect, a control method for setting a rolling mill roll gap safety protection comprises the following steps:

[0011] The rolling line PLC receives the model roll gap setting of the upper computer, combines the actual width data of the rolled steel plate measured by the rough rolling mill side guide plate as the roll gap logic setting, and re-establishes the roll gap setting logic and error protection control by collecting the hot metal detector signal.

[0012] Preferably, the control method specifically comprises the following steps:

[0013] S1, the upper computer sets a model roll gap;

[0014] S2, the rolling line main PLC receives the steel plate BID (steel plate sequence marker), the reduction amount, and the pass number;

[0015] S3, the rolling line main PLC judges whether the rough rolling mill is allowed to enter the steel, if yes, it goes to step S4, and if no, it returns to step S2;

[0016] S4, rough rolling;

[0017] S5, the rough rolling mill PLC judges whether the width, width-thickness ratio, and length of the next pass of the rolled steel plate meet the use conditions of the roll mill, if yes, it goes to step S6, and if no, it returns to step S5;

[0018] S6, the rough rolling mill PLC sends a request to the upper computer to use the roll mill;

[0019] S7, the roll mill PLC receives the roll gap setting of the steel plate, the BID (steel plate sequence marker) sent by the upper computer, and the BID (steel plate sequence marker) sent by the rough rolling mill PLC;

[0020] S8, when the rough rolling mill pass is zero, the roll mill PLC judges whether the received steel plate BID (steel plate sequence marker) is consistent, if yes, it goes to step S9, and if no, the roll gap of the roll mill is automatically set to a safe position;

[0021] S9, the roll mill PLC sends a roll gap setting permission command;

[0022] S10, the rough rolling mill PLC issues a command to measure the width of the rolled steel plate by the side guide plate;

[0023] S11, the rough rolling mill PLC records the last time the width of the rolled steel plate is measured by the side guide plate before using the roll mill;

[0024] S12, the vertical roll rolling mill PLC receives the steel plate measurement width, and compares with the steel plate roll gap issued by the upper computer, and takes the maximum value as the final setting of the vertical roll roll gap;

[0025] S13, the rolling line main PLC judges whether the rough rolling mill and the vertical roll rolling mill allow the steel to enter, if yes, it enters step S14, if not, it returns to step S12;

[0026] S14, the rolling line main PLC sends the vertical roll rolling mill PLC to use the vertical roll rolling mill action command;

[0027] S15, the vertical roll rolling mill starts to act;

[0028] S16, it is judged whether the vertical roll rolling mill acts to the target position, if yes, it enters step S17, if not, it returns to step S15;

[0029] S17, the vertical roll rolling mill enters the steel and starts rolling;

[0030] S18, the tail of the rolled steel plate leaves the hot metal detector, and the vertical roll rolling is completed;

[0031] S19, waiting for the next rolled steel plate, and the vertical roll rolling starts.

[0032] On the other hand, a rolling line, comprising a descaling box, a vertical roll rolling mill, a rough rolling mill and a finishing mill arranged in sequence along the running direction of the rolled steel plate, an inlet side guide plate position sensor is arranged between the descaling box and the vertical roll rolling mill, an outlet side guide plate position sensor is arranged between the rough rolling mill and the vertical roll finishing mill, and a hot metal detector is arranged between the rough rolling mill and the outlet side guide plate position sensor;

[0033] The rolling line is used to realize the control method for setting the safety protection of the roll gap of the rolling mill.

[0034] The control method for setting the safety protection of the roll gap of the rolling mill and the rolling line provided by the application avoid the occurrence of the defects of the prior art, increase the hourly capacity, reduce the energy loss during abnormal shutdown, and reduce the equipment maintenance cost. It can be applied to the roll gap setting control of similar wide and thick plate vertical roll rolling mills, and has wide popularization value. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a schematic diagram of the existing vertical roll rolling mill area site arrangement;

[0036] Figure 2 is a schematic diagram of the vertical roll mechanical pressure, working roll balance and hydraulic pressure site arrangement;

[0037] Figure 3 is a schematic diagram of the flow of the control method of the application;

[0038] Figure 4is a schematic diagram of the rolling line field layout of the present application;

[0039] Figure 5 is a control principle diagram of the rolling line of the present application. DETAILED DESCRIPTION

[0040] In order to better understand the above technical solutions of the present application, the technical solutions of the present application are further described below in combination with the drawings and embodiments.

[0041] In combination with Figure 3 and Figure 5 as shown, the control method for setting the safety protection of the roll gap of the rolling mill provided by the present application comprises the following steps:

[0042] The rolling line PLC receives the model stand roll gap setting of the upper computer, combines the actual width data of the rolled steel plate measured by the rough rolling mill side guide plate, and sets the stand roll gap logic, re-establishes the roll gap setting logic and error protection control by collecting the hot metal detector signal.

[0043] The control method specifically comprises the following steps:

[0044] S1, the upper computer sets the model stand roll gap;

[0045] S2, the rolling line main trunk PLC receives the steel plate BID (steel plate sequence marker), the reduction amount and the pass number;

[0046] S3, the rolling line main trunk PLC judges whether the rough rolling mill is allowed to enter the steel, if yes, it goes to step S4, and if no, it returns to step S2;

[0047] S4, rough rolling;

[0048] S5, the rough rolling mill PLC judges whether the width (greater than 2.2m and less than 4.2m), the width-thickness ratio (greater than 0 and less than 60), and the length (greater than 6m) of the next pass of the rolled steel plate meet the use conditions of the stand roll mill, if yes, it goes to step S6, and if no, it returns to step S5;

[0049] S6, the rough rolling mill PLC sends the upper computer to request the use of the stand roll mill;

[0050] S7, the stand roll mill PLC receives the roll gap setting of the steel plate, the BID (steel plate sequence marker) and the steel plate BID (steel plate sequence marker) sent by the rough rolling mill PLC issued by the upper computer;

[0051] S8, when the pass number of the rough rolling mill is zero, the stand roll mill PLC judges whether the received steel plate BID (steel plate sequence marker) is consistent, if yes, it goes to step S9, and if no, the roll gap of the stand roll mill is automatically set to a safe position (greater than 5m);

[0052] S9, the vertical roll mill PLC sends a permission roll gap setting command;

[0053] S10, the roughing mill PLC sends a command to measure the width of the rolled steel plate by the side guide plate;

[0054] S11, the roughing mill PLC records the last time the width of the rolled steel plate is measured by the side guide plate before the vertical roll mill is used;

[0055] S12, the vertical roll mill PLC receives the measured width of the steel plate and compares it with the roll gap of the steel plate sent by the upper computer, and takes the maximum value as the last setting of the vertical roll gap;

[0056] S13, the main PLC of the rolling line judges whether the roughing mill and the vertical roll mill are allowed to enter the steel, if yes, it goes to step S14, if not, it returns to step S12;

[0057] S14, the main PLC of the rolling line sends a vertical roll mill PLC vertical roll mill action command;

[0058] S15, the vertical roll mill starts to act;

[0059] S16, it is judged whether the vertical roll mill has acted to the target position, if yes, it goes to step S17, if not, it returns to step S15;

[0060] S17, the vertical roll mill enters the steel and starts to roll;

[0061] S18, the tail of the rolled steel plate leaves the hot metal detector (installed at a position of 48.42 m), and the vertical roll rolling is completed;

[0062] S19, it waits for the next rolled steel plate, and the vertical roll rolling starts.

[0063] In combination Figure 4 As shown in the drawings, the present application also provides a rolling line, which comprises a descaling box, a vertical roll mill 5, a roughing mill 6 and a finishing mill arranged in sequence along the running direction of the rolled steel plate, an inlet side guide plate position sensor 7 is arranged between the descaling box and the vertical roll mill 5, an outlet side guide plate position sensor 8 is arranged between the roughing mill 6 and the vertical finishing mill, and a hot metal detector 9 is arranged between the roughing mill 6 and the outlet side guide plate position sensor 8.

[0064] Those skilled in the art should understand that the above embodiments are only used to illustrate the present application, and are not used as a limitation of the present application, as long as the changes and modifications of the above described embodiments are within the scope of the spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A control method for setting the safety protection of a rolling mill roll gap, characterized in that: the rolling line PLC receives the model stand roll gap setting from the upper computer, combines the actual width data of the rolled steel plate measured by the rough rolling mill side guide plate as the stand roll gap logical setting, and re-establishes the roll gap setting logic and error protection control by collecting the hot metal detector signal, the control method specifically comprises the following steps: S1, the upper computer sets the model stand roll gap; S2, the rolling line main PLC receives the steel plate BID, the reduction amount and the pass number; S3, the rolling line main PLC judges whether the rough rolling mill is allowed to enter the steel, if yes, it goes to step S4, if not, it returns to step S2; S4, the rough rolling mill rolls; S5, the rough rolling mill PLC judges whether the width, width-thickness ratio and length of the next pass of the rolled steel plate meet the use conditions of the stand rolling mill, if yes, it goes to step S6, if not, it returns to step S5; S6, the rough rolling mill PLC sends the upper computer to request the use of the stand rolling mill; S7, the stand rolling mill PLC receives the roll gap setting of the steel plate issued by the upper computer, the BID of the steel plate and the BID of the steel plate sent by the rough rolling mill PLC; S8, when the pass number of the rough rolling mill is zero, the stand rolling mill PLC judges whether the received steel plate BID is consistent, if yes, it goes to step S9, if not, the roll gap of the stand rolling mill is automatically set to a safe position; S9, the stand rolling mill PLC sends the roll gap setting command; S10, the rough rolling mill PLC issues the command of measuring the width of the rolled steel plate by the side guide plate; S11, the rough rolling mill PLC records the last time of measuring the width of the rolled steel plate by the side guide plate before using the stand rolling mill; S12, the stand rolling mill PLC receives the measured width of the steel plate and compares it with the roll gap of the steel plate issued by the upper computer, and takes the maximum value as the final setting of the stand roll gap; S13, the rolling line main PLC judges whether the rough rolling mill and the stand rolling mill are allowed to enter the steel, if yes, it goes to step S14, if not, it returns to step S12; S14, the rolling line main PLC sends the action command of the stand rolling mill PLC to use the stand rolling mill; S15, the stand rolling mill starts to act; S16, it is judged whether the stand rolling mill has acted to the target position, if yes, it goes to step S17, if not, it returns to step S15; S17, the stand rolling mill enters the steel to start rolling; S18, the tail of the rolled steel plate leaves the hot metal detector, and the stand rolling is completed; S19, it waits for the next rolled steel plate, and the stand rolling starts.

2. The control method for rolling mill gap safety setting according to claim 1, characterized in that: In step S5, the width of the next pass of the rolled steel plate is greater than 2.2m and less than 4.2m, the width-thickness ratio is greater than 0 and less than 60, and the length is greater than 6m.

3. The control method for rolling mill gap safety setting according to claim 1, characterized in that: In step S8, the safe position of the automatic setting of the roll gap of the stand rolling mill is greater than 5m.

4. The control method for rolling mill gap safety setting according to claim 1, characterized in that: In step S18, the distance from the hot metal detector to the rolled steel plate is 48.42m.

5. A rolling line comprising, in the running direction of the steel sheet to be rolled, a descaling box, an edger mill, a roughing mill and a finishing mill, characterized in that: An inlet side guide position sensor is arranged between the descaling box and the stand rolling mill, an outlet side guide position sensor is arranged between the rough rolling mill and the finishing mill, and a hot metal detector is arranged between the rough rolling mill and the outlet side guide position sensor; The rolling line is used to realize the control method for setting the safety protection of the rolling mill roll gap according to any one of claims 1-4.

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