Automatic control scheme for hot delivery of bar h

2022-08-14
  • Detail

This paper briefly introduces the automatic control system of hot delivery of 600000 ton bar heating furnace in Xin rolling plant of Shanxi Haixin iron and steel company. The original design is from Beijing Iron and steel design and Research Institute. The PLC adopts American GE. Ethernet, genius and PROFIBUS are the structures of the original material performance. On the basis of the original program structure, the author reformulated and reprogrammed the control scheme of the main equipment, of which the most critical is the positioning control of the hot billet traverse bench; The control method was pointed out by Yue Chun, Chief Electrical Engineer of Beijing Iron and steel design and Research Institute. I myself calculated and tested it with half a month of low energy consumption. At present, the hot delivery of bars in the Xin rolling plant of Haixin company has been successful for nearly a year, and the hot delivery roller table to the roller table of section I into the furnace are all automatic and operate well

II. Keywords

low temperature hot metal detector, encoder, high-speed counter, cold and hot metal detector, frequency conversion and speed regulation

III. overview

hot delivery of heating furnace realizes continuous casting and rolling of our company. After hot delivery of billet, the consumption of heating furnace gas will be significantly reduced, providing favorable conditions for gas power generation of our company

IV. introduction to main equipment and process

the billets pulled out by the 2 # continuous caster of the Second Steelmaking Plant of our company are turned over from the cooling bed on the north side to the output roller table (Section 1 of the hot delivery roller table). Because the bar plant and the steelmaking plant are not vertical and form an angle of 85 degrees, the section 2 of the hot delivery roller table is a group of oscillating roller tables. After the hot delivery roller table 2 is aligned with the hot delivery roller table 1, the hot delivery roller table 1 is unloaded and the hot delivery roller table 2 is loaded. After the steel-making billets are sent to the designated position of the hot delivery 2 roller table, the hot delivery 2 roller table swings with the billets to align with the hot delivery 3 roller table, the hot delivery 2 roller table unloads and the hot delivery 3 roller table loads. After the steel billet enters the designated position of the hot delivery section 3 roller table, the chain claw of the hot billet traverse table starts to push the steel billet onto the hot billet elevator, which lifts the steel billet for large-span and seismic building structure to the furnace section 1 roller table. As long as the billet is smoothly delivered to the furnace roller table, the hot delivery is successful

the first section of the hot delivery roller table is under the control of steelmaking, and the second section of the hot delivery roller table is under the control of Xin rolling bar. The second section of the hot delivery roller table and the hot billet traverse table are controlled by frequency conversion, the third section of the hot delivery roller table is controlled by MCC, and the swing cylinder and hoist of the second section of the hot delivery roller table are controlled by hydraulic pressure. Since the whole control is greatly changed compared with the original design, the original control is no longer described

v. automatic control function of hot delivery

automatic control of hot delivery can be divided into the following parts:

1. Production signal exchange of steel making and bar

2. Automatic control of hot delivery roller table

3. Automatic control of hot billet traverse table

4. Automatic control of hot billet elevator

the following will be introduced one by one

VI. production signal exchange of steel making and bar

1 The signal of bar steel sending

1.1 is ready (this cooperation between bar steel and DuPont uses a button with light on the biological continuable 1 console with patented technology from wonz)

after all the equipment in the hot delivery area enter the automatic state, press the ready light button, and the ready light is on {press the light off again}. It indicates that the bar production line is ready, and this signal is transmitted to the No. 2 continuous caster for steelmaking, waiting for steelmaking to send hot billets

the ready light is off, indicating that the bar production line is not ready, and it is required to stop supplying hot billets to the bar

1.2 steel demand signal (a lighted button is used on the bar 1 console)

1.2.1 manual steel demand

in the ready state, the hot delivery 2 roller table is aligned with the steel-making roller table, press the steel demand light button, and the steel demand light flashes, indicating that a steel is required for steel-making. This signal is also transmitted to steelmaking No. 2 continuous caster

1.2.2 automatic steel demand

in the ready state, quickly press the steel demand light button twice (within 1 second) to enter the automatic steel demand state; After the hot delivery 2 roller table is aligned with the steel-making roller table, the light is on. Otherwise, the light goes out. This signal is also transmitted to steelmaking No. 2 continuous caster

2. Steel making bar signal sent to Xin rolling plant (a signal light is displayed on the bar 1 console)

2.1 the light flashes, which is the first production signal from steel making, indicating that the production of No. 2 continuous caster is normal and has the conditions to provide hot billets for bars

2.2 the light is on, which is the second production signal from steel-making, indicating that the steel-making billet has arrived on the hot delivery section 1 roller table, and the bar is required to start hot delivery immediately

2.3 the light is off, indicating that No. 2 continuous caster does not have the conditions for hot delivery

the ready signal of the two plants is the premise for the start of hot delivery. The disappearance of the ready signal of either party means that the hot delivery is interrupted. During the hot delivery process, steelmaking 2 continuous casting sends a billet to the bar as long as it sees the signal of steel demand

VII. Automatic control scheme of hot delivery roller table

select automatic steel demand, the hot delivery section 2 is in the initial position, and the steel demand indicator light is on; The steel-making 2# continuous casting console starts the hot delivery 1 roller table; A low-temperature hot metal detector (hereinafter referred to as "hot inspection") is arranged at the entrance of the second section of the hot delivery roller table. When the steel-making billet enters the second section of the hot delivery roller table, the hot inspection sends a steel signal, and the second section of the hot delivery roller table starts automatically. The second thermal inspection is arranged 4 meters away from the end of the second section of the hot delivery roller table. When the second thermal inspection detects a steel signal, it will delay, and the hot delivery roller table 2 will automatically stop running. After the steel indicator light disappears, the swing cylinder automatically swings to align with the 3-stage roller table, the 2-stage hot delivery roller table and the 3-stage hot delivery roller table are automatically started at the same time. When the billet leaves the 2-stage hot delivery roller table, the 2-stage hot delivery roller table automatically stops running, the swing cylinder automatically swings back to align with the 1-stage hot delivery roller table, the steel indicator light automatically turns on, and the next steel is automatically asked for steelmaking. The billet entering the third section of the hot delivery roller table will automatically stop after a steel delay is detected through the thermal inspection of the third section of the hot delivery roller table. At this point, the hot delivery of the roller table is completed

VIII. Automatic control scheme of hot billet traverse platform

figure 1

(the figure shows that there is steel on the hot billet elevator, and the claw will automatically return after pushing the billet out 2.5 meters away from the original position every time)

the structure of the hot billet traverse platform (hereinafter referred to as the platform) is shown in Figure 1. It is a horizontal traverse device driven by chain, with the starting position of 3 sections of the hot delivery roller table and the ending position of the hot billet elevator (hereinafter referred to as the elevator). Through the one-way claw on the chain, the billets of the three sections of the hot delivery roller table are pushed into the bench, and finally all are pushed onto the elevator, which is the key equipment to realize hot delivery. The total length of the bench is 6 meters. Due to the limitation of steel drawing capacity, it can store 12 steel billets (later changed to 15 according to the actual situation). It is a buffer area for hot delivery between the two plants. In the process of hot delivery, the number of billets on the bench will change with the change of production rhythm

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