Flat rolling

FLAT ROLLING

1. Flatness control system of cold rolling process with pneumatic bearing type shape roll Submitted by Sarda sinde ME 4 th year 1216140088 1

2. contents Introduction Need Pneumatic bearing type shape roll Automatic control system used in rolling 2

3. I ntroduction Use of automatic control system in cold rolling process Flatness control in rolling processes is widely used for steel and nonferrous metals, such as aluminum and copper. The roll shape is developed by applying the principle of pneumatic bearing 3

4. Need Thinner and stronger rolls Higher quality of rolls Shape control Analysis of all the factors involved in cold rolling processes 4

5. Pneumatic bearing type shape roll Pneumatic bearing or air bearing uses a thin film of pressurized air to provide an exceedingly low friction load-bearing interface between surfaces 5 The shape is made by the relation between the cross-sectional profile (also referred to as the crown) of the material and the profile of the gap between mill rolls If the material is rolled uniformly and elongated evenly over the strip width, it has a flat shape

6. 6 Shape of roll if material has not evenly elongated Wavy edges Centre buckles (b) Wavy edges ges ( a ) Flat shape (c) Centre buckles

7. Features of pneumatic bearing type shape rolls Simple structure eliminating the need to use auxiliary drives Low rotation resistance owing to rotors supported by the pneumatic bearing High sensitivity (able to detect a change in load smaller than .1 n) Capability to continuously detect the shape . 7

8. Configuration…. Sectional view of pneumatic bearing type rolls 8 Rotor Rolled material Nozzle Upper pressure port Lower pressure port Air film Arbor

9. Automatic shape control During rolling, mill profile is subjected to changes because of deflection and thermal expansion and thereby the shape of material is determined by Fourier series expansion 9

10. Configuration of automatic control system Shape control Control equipment 10

11. 11 Strip shape is controlled by operating the shape control actuators of the rolling mills based on the analysis result Shape control Control equipment In a cold rolling process, materials are processed at a maximum speed higher than 30 m/s, and changes in strip shape are steadily determined and controlled by making calculations every 0.05 second from shape detection to control output.

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13. thank you 13