| 摘要 |
A system for controlling the difference between the velocity of a pulp slurry discharging from a paper machine headbox and the speed of the fourdrinier wire onto which said pump slurry is deposited. The system includes means for deriving a signal representative of the aforementioned speed differential thus allowing a direct comparison between the actual velocity differential and the desired velocity differential. The control system is based upon a differentiated and rearranged form of the equation v2=2gh which is dv=(g/v)dh, wherein dv = the rush or drag in units of speed, v = the wire speed, g = the gravitational constant, and dh = the differential head, i.e., that part of the total head which gives rise to the velocity difference between the slice velocity and the wire speed, in units of inches of H20.
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