1 Introduction – A Brief of Digital Fluid Control
2 Examples
2.1 Roller Gap Adjustment in Continuous Casting
2.2 Pulsed Secondary Cooling
2.3 Hydraulic Gap Control for Rolling Mills
Parameter | Value | ||
---|---|---|---|
Fluid
| |||
Fluid compression modulus |
\(E\)
|
\(bar\)
| 14000 |
Fluid density |
\(\rho\)
|
\(kg/m^{3}\)
| 860 |
Fluid kinematic viscosity |
\(\nu\)
|
\(mm^{2}/s\)
| 46 |
Cylinder
| |||
Piston diameter |
\(d_{P}\)
|
\(m\)
| 0.98 |
Rod diameter |
\(d_{R}\)
|
\(m\)
| 0.82 |
Piston area |
\(A_{P}\)
|
\(m^{2}\)
| 0.75 |
Rod side area |
\(A_{R}\)
|
\(m^{2}\)
| 0.23 |
Mass
|
\(m\)
|
\(kg\)
| 15000 |
Piston reference position |
\(S_{0}\)
|
\(m\)
| 0.1 |
Piston stroke |
\(S_{max}\)
|
\(m\)
| 0.15 |
Cylinder+rolls damping |
\(d_{cyl}\)
|
N/(m/s)
| 1e6 |
Pipeline
| |||
Pipeline length |
\(L\)
|
\(m\)
| 2 |
Pipe diameter |
\(d\)
|
\(m\)
| 0.032 |
Rod side channel length |
\(L_{RS}\)
|
\(m\)
| 0.25 |
Rod side channel diameter |
\(d_{RS}\)
|
\(m\)
| 0.016 |
Servo valve
| |||
Nominal flow |
\(q_{SV}\)
|
\(l/min\)
| 75 |
Nominal pressure drop |
\(\Updelta p_{SV}\)
|
\(bar\)
| 70 |
Valve cut-off frequency |
\(f_{SV}\)
|
\(Hz\)
| 100 |
Valve dynamics damping |
\(d_{SV}\)
| 0.6 | |
Digital valve
| |||
Nominal flow |
\(q_{SV}\)
|
\(l/min\)
| 7 |
Nominal pressure drop |
\(\Updelta p_{SV}\)
|
\(bar\)
| 5 |
Valve switching frequency |
\(Hz\)
| 20 | |
Valve switching time | ms | 7 | |
Hydraulic supply parameters | |||
Supply pressure |
\(p_{Sys}\)
|
\(bar\)
| 200 |
Tank pressure |
\(p_{T}\)
|
\(bar\)
| 15 (1 for servo) |
Steel
| |||
Steel stiffness |
\(C_{strip}\)
|
\(N/m\)
| 1e10 |
Steel damping |
\(d_{strip}\)
|
N/(m/s)
| 1e8 |