Parameters affecting disturbance propagation through the wet-end of a paper machine

Historically, piping networks in the wet end of paper machines are assumed to add little to the dynamics outside pure transport delay. Consequently large vessels are included simply to dampen incoming stock concentration variations. This paper challenges this assumption by showing that including mixing and inertia terms in the piping equations, the pipe layout has a large effect in the important region of 10[-3] to 10[-1] Hz where stock concentration variations are present, but are outside the influence of the regulatory control systems.