Method for reducing tapping accidents of walking beam furnace

Abstract

The invention discloses a method for reducing tapping accidents of a walking beam furnace, which relates to the technical field of walking beam furnaces and comprises the following steps: determining the limit overflow amount of a steel billet; an overflow amount threshold value is set based on the limit overflow amount of the steel billet, an alarm is given when the overflow amount of the steel billet is larger than the set overflow amount threshold value, and automatic tapping is forbidden; the stepping beam is switched to a manual mode, the stepping mechanism is manually lifted, retreated by a half stroke and descended and retreated to an initial position, an automatic circulation mode is started, and the steel billet overflow amount is corrected; and after the steel billet overflow amount is corrected, automatic tapping is carried out. By adding an overflow amount error alarm reminding function, tapping accidents caused by large overflow amount deviation or a limit value are effectively avoided, meanwhile, the overflow amount is adjusted and corrected through the stepping mechanism, and tapping accidents caused by improper operation or observation of manual tapping are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of walking beam heating furnaces, and in particular to a method for reducing steel tapping accidents in walking beam heating furnaces. Background Art

[0002] The walking beam heating furnace is the main furnace type for heating slabs in the current steel industry. The billet is moved forward step by step through the circular motion of the walking beam. The furnace door will be equipped with a laser detection point. When the billet encounters the laser detection point during the operation, the system defaults to the steel tapping area. After this step cycle is completed, it reaches the steel tapping position. The overflow refers to the distance from the front end of the billet to the laser line when the billet reaches the steel tapping position. The overflow is included in the calculation of the steel tapping machine stroke.

[0003] The stroke of the steel tapping machine S = S0 + W / 2-Y, where: S0-the distance from the center line of the steel tapping roller to the laser detector; W-the width of the steel billet; Y-the overflow amount. The above formula S0 and W are known before steel tapping. When the overflow amount Y is too small, the stroke S is too large, and the steel tapping machine support arm may lift the steel billet near the steel tapping position; when the overflow amount Y is too large, the stroke S is too small, and the current steel tapping slab cannot be effectively lifted. The above situation will cause the steel billet to tilt or fall, resulting in unplanned downtime or furnace shutdown. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the disadvantages of the prior art and provide a method for reducing steel tapping accidents in a walking beam heating furnace.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows: A method for reducing steel tapping accidents in a walking beam heating furnace, comprising: Determine the limit overflow of the billet; An overflow threshold is set based on the limit overflow amount of the steel billet, and an alarm is issued when the overflow amount of the steel billet is greater than the set overflow threshold, and automatic steel tapping is prohibited; Switch the stepping beam to manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic cycle mode, and correct the overflow of the billet; Automatic steel tapping is performed after the billet overflow correction is completed.

[0006] As a preferred solution of the method for reducing steel-tapping accidents in a walking beam heating furnace according to the present invention, the method further comprises: When the current billet reaches the steel-out position, the theoretical overflow amount of the next billet is calculated according to the position in the furnace; Obtain the actual overflow amount of the next steel billet, and when the actual overflow amount is greater than the theoretical overflow amount and the difference between the two is greater than or equal to the difference threshold, an alarm is issued and automatic steel tapping is prohibited; Switch the stepping beam to manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic cycle mode, and correct the overflow of the billet; Automatic steel tapping is performed after the billet overflow correction is completed.

[0007] As a preferred solution of the method for reducing steel tapping accidents in the walking beam heating furnace of the present invention, when the current steel billet reaches the steel tapping position, calculating the theoretical overflow amount of the next steel billet according to the position in the furnace includes: The theoretical overflow of the next steel billet is calculated according to the following formula: Y0=nB0-(W1-Y1+W0), where B0 is the stepping stroke, W1 is the width of the current steel billet; Y1 is the actual overflow of the current steel billet; and W0 is the steel loading spacing.

[0008] As a preferred solution of the method for reducing steel-tapping accidents in a walking beam heating furnace according to the present invention, the difference threshold is 50 mm.

[0009] As a preferred solution of the method for reducing steel tapping accidents in the walking beam heating furnace of the present invention, wherein: after switching the walking beam to the manual mode, manually lifting the walking mechanism, retreating half a stroke, descending and retreating to the initial position, starting the automatic circulation mode, and correcting the overflow of the billet, it also includes: Determine whether the steel billet still blocks the laser detection point. If so, perform a reverse cycle first and then a forward cycle.

[0010] The beneficial effects of the present invention are: (1) The present invention effectively avoids steel tapping accidents caused by large deviation or limit value of overflow amount by adding an overflow amount error alarm reminder function.

[0011] (2) The present invention adjusts and corrects the overflow amount through a stepping mechanism, thereby avoiding steel tapping accidents caused by inadequate operation or observation during manual steel tapping.

[0012] (3) After the overflow amount is corrected, the fully automatic steel tapping efficiency is high and the temperature uniformity of the steel billet is good. DETAILED DESCRIPTION

[0013] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation methods.

[0014] There are two main factors affecting the inaccurate overflow during the production process: 1) Critical position, that is, when the front end of the billet stops running and contacts the laser detection (the overflow amount is 0), the billet just moves forward and contacts the laser to complete the last stroke (the overflow amount is the largest). This type of steel tapping stroke is at the limit position, and coupled with the walking deviation of the steel tapping machine, accidents are prone to occur during the steel tapping process; 2) For the two independently running stepping mechanisms in the furnace, when the billets on the two stepping beams are performing the last stepping cycle, the billet that contacts the laser inspection first may trigger the other laser inspection at the same time, causing the overflow amount of the other billet to be calculated before it contacts the laser inspection, resulting in an error in the overflow amount of the diverted billet and an error in the stroke of the automatic steel-tapping machine, causing a steel-tapping accident.

[0015] The present application embodiment provides a method for reducing steel tapping accidents in a walking beam heating furnace, the method comprising the following steps: Step S101: Determine the limit overflow amount of the steel billet.

[0016] Step S102: an overflow threshold is set based on the limit overflow amount of the steel billet, and an alarm is issued when the overflow amount of the steel billet is greater than the set overflow threshold, and automatic steel tapping is prohibited.

[0017] Step S103: Switch the stepping beam to the manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic circulation mode, and correct the overflow of the billet.

[0018] Step S104: Automatically tapping the steel after the correction of the overflow amount of the steel billet is completed.

[0019] It should be noted that the above two steps are for the above influencing factor 1. For the above influencing factor 2, the specific steps are as follows: Step S201: When the current billet reaches the steel-out position, the theoretical overflow amount of the next billet is calculated according to the position in the furnace.

[0020] Specifically, the theoretical overflow amount of the next billet is calculated according to the following formula: , where B0 is the stepping process, W1 is the width of the current billet; Y1 is the actual overflow of the current billet; and W0 is the steel loading spacing.

[0021] Step S202: obtaining the actual overflow amount of the next steel billet, and when the actual overflow amount is greater than the theoretical overflow amount and the difference between the two is greater than or equal to the difference threshold, an alarm is issued and automatic steel tapping is prohibited.

[0022] Specifically, based on the formula in step S201, when the current billet reaches the tapping position, the distance (W1-Y1+W0) of the next billet from the laser detector can be calculated. The stepping stroke (B0) is known, and the number of stepping cycles n to reach the tapping position can be calculated to obtain the theoretical overflow amount Y0. When the billet contacts the laser detector during operation, the actual overflow amount Y is obtained. When Y-Y0 ≥ 50mm, the system adds an overflow error alarm and prohibits automatic tapping.

[0023] Step S203: Switch the stepping beam to the manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic circulation mode, and correct the overflow of the billet.

[0024] Step S204: Automatically tapping the steel after the correction of the overflow amount of the steel billet is completed.

[0025] It should be noted that in the above steps S103 and S203, if the laser detection point is still blocked after manually retreating half the stroke, a reverse cycle is performed first and then a forward cycle is performed.

[0026] The above scheme is described below through specific embodiments: Example 1: A walking beam heating furnace, double-row independent walking mechanism, walking stroke 600mm, steel tapping laser detection distance to steel tapping furnace door 1.6mm, steel tapping roller to laser detection distance 3.5m, steel transfer spacing 80mm. The operation steps are as follows: 1. The system increases the overflow error alarm: 0mm≤Y≤50mm, 550mm≤Y≤600mm, 50mm≤Y-Y0.

[0027] 2. Billet No. 2410034801 (plate width 2570mm), overflow error alarm after reaching the steel tapping position; 3. Confirm the alarm information that the overflow of furnace 1# is 590mm, and manually retreat half the stroke; 4. After retreating half of the stroke, the 1# furnace 1st channel is in contact with the steel billet, and the semi-automatic reverse cycle of the stepping mechanism is started. After the reverse cycle stops, it is switched to the automatic mode, and the forward cycle reaches the steel position. The overflow volume is displayed as 315mm, and the alarm information processing is confirmed, and the alarm prompt sound is eliminated; 5. When the rolling mill issues a steel tapping request, click on 1# furnace 1st pass steel tapping, and the steel billet will be tapped automatically, and the process is normal.

[0028] Example 2: A walking beam heating furnace, double-row independent walking mechanism, walking stroke 600mm, steel tapping laser detection distance to steel tapping furnace door 1.6mm, steel tapping roller to laser detection distance 3.5m, steel transfer spacing 80mm. The operation steps are as follows: 1. The system increases the overflow error alarm: 0mm≤Y≤50mm, 550mm≤Y≤600mm, 50mm≤Y-Y0.

[0029] 2. Billet No. 2420052802 (plate width 2570mm), overflow error alarm after reaching the steel tapping position; 3. Confirm the alarm information that the overflow deviation of the 2nd channel of furnace 1# is 112mm, and manually retreat half the stroke; 4. After retreating half a stroke, the second laser inspection of furnace 1# is not connected, the billet is not at the steel-out position, and the positive cycle automatic mode is started to the steel position, and the overflow volume is displayed as 428mm; 5. When the rolling mill issues a steel tapping request, click on 1# furnace 2 tapping, and the billet will be tapped automatically, and the process is normal.

[0030] Therefore, the technical solution of the present application effectively avoids steel tapping accidents caused by large overflow deviation or limit value by adding an overflow error alarm reminder function. At the same time, the overflow is adjusted and corrected by the stepping mechanism to avoid steel tapping accidents caused by manual operation or inadequate observation.

[0031] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for reducing steel tapping accidents in a walking beam heating furnace, characterized in that: include: Determine the limit overflow of the billet; An overflow threshold is set based on the limit overflow amount of the steel billet, and an alarm is issued when the overflow amount of the steel billet is greater than the set overflow threshold, and automatic steel tapping is prohibited; Switch the stepping beam to manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic cycle mode, and correct the overflow of the billet; Automatic steel tapping is performed after the billet overflow correction is completed.

2. The method for reducing steel tapping accidents in a walking beam heating furnace according to claim 1, characterized in that: Also includes: When the current billet reaches the steel-out position, the theoretical overflow amount of the next billet is calculated according to the position in the furnace; Obtain the actual overflow amount of the next steel billet, and when the actual overflow amount is greater than the theoretical overflow amount and the difference between the two is greater than or equal to the difference threshold, an alarm is issued and automatic steel tapping is prohibited; Switch the stepping beam to manual mode, manually lift the stepping mechanism, retreat half the stroke, lower it and retreat to the initial position, start the automatic cycle mode, and correct the overflow of the billet; Automatic steel tapping is performed after the billet overflow correction is completed.

3. The method for reducing steel tapping accidents in a walking beam heating furnace according to claim 2, characterized in that: When the current billet reaches the steel-out position, calculating the theoretical overflow amount of the next billet according to the position in the furnace includes: The theoretical overflow of the next billet is calculated according to the following formula: , where B0 is the stepping process, W1 is the width of the current billet; Y1 is the actual overflow of the current billet; and W0 is the steel loading spacing.

4. The method for reducing steel tapping accidents in a walking beam heating furnace according to claim 2, characterized in that: The difference threshold is 50 mm.

5. The method for reducing steel tapping accidents in a walking beam heating furnace according to claim 1, characterized in that: After switching the stepping beam to the manual mode, manually lifting the stepping mechanism, retreating half of the stroke, lowering and retreating to the initial position, starting the automatic circulation mode, and correcting the overflow of the steel billet, the method further includes: Determine whether the steel billet still blocks the laser detection point. If so, perform a reverse cycle first and then a forward cycle.