| 摘要 |
<p>To set a consistent characteristic lateral profile in a paper web, the weight cross section profile is measured and adjusted by setting the sectional pulp density at the stock inlet. The lateral formation profile is then set by amending the specific pulp throughput at the delivery jet of the stock inlet. Simultaneously or subsequently, the dimensions of the delivery jet are increased or decreased at points where there is a raised pulp throughput. The change in the delivery jet is proportional to the change in the specific pulp throughput and, after setting, the flow is at the required lateral speed profile. At least one of the setting steps is effected by a control circuit. Additional chemicals are added pref. at the edge zone, to delay and/or increase the water extraction rate from the pulp. The variations in the specific pulp suspension flows are through sectional extraction or addition of a fluid in the Z-direction, together with filling materials where there are zones with a higher throughput. The technique is especially for a paper making machine with a double fourdrinier.</p> |
