초록 ▼

Method and apparatus for controlling the transverse distribution of pressure applied to a web passing through a nip formed between a pressure zone-adjustable device having a first number (K) of separately adjustable pressure zones, including those for roll loading cylinders, if any, and a counter-me

Method and apparatus for controlling the transverse distribution of pressure applied to a web passing through a nip formed between a pressure zone-adjustable device having a first number (K) of separately adjustable pressure zones, including those for roll loading cylinders, if any, and a counter-member. A desired linear load profile comprising a second number (N) of setting zone set values for a corresponding number (N) of setting zones is provided, the second number (N) of the setting zones being substantially greater than the first number (K) of actual pressure zones. The second number (N) of setting zone set values are input to a zone conversion unit which is programmed with a mathematical model of the nip and are converted to a first number (K) of pressure zone set values so than an actual transverse distribution of pressure applied to the web is obtained having a minimal deviation from the setting zone set value distribution. In particular, the first number (K) of pressure zone set values are input into an intelligent regulating unit provided with diagnostic and protection logic so as to constitute set values for desired zone pressures. The pressure applied to each of the loading members or loading member groups of the nip to be controlled is determined separately by respective pressure zone set values.

대표청구항 ▼

In a method for controlling the pressure profile or transverse distribution of pressure applied to a web passing through an adjustable nip formed between a zone-adjustable device and a counter-member, said zone-adjustable device including a first number (K) of separately adjustable loading means act

In a method for controlling the pressure profile or transverse distribution of pressure applied to a web passing through an adjustable nip formed between a zone-adjustable device and a counter-member, said zone-adjustable device including a first number (K) of separately adjustable loading means actuated by a first number (K) of separately adjustable actual pressure zones, including the steps of generating a first number (K) of pressure zone set values, inputting said first number (K) of pressure zone set values to regulating means for regulating the pressures of said first number (K) of actual pressure zones in accordance with the values of said first number (K) of pressure zone set values, the improvement comprising an improved method for generating said first member (K) of pressure zone set values, comprising the steps of: inputting a profile or distribution of setting zone set values corresponding to a desired pressure profile or transverse pressure distribution in the nip into a zone conversion means, said setting zone set value profile or distribution comprising a second number (N) of setting zone set values for a corresponding second number (N) of setting zones; said second number (N) of setting zones being substantially greater than said first number (K) of separately adjustable actual pressure zones (N>>K) of said zone-adjustable device; and converting said second number (N) of the setting zone set values input into said zone conversion means into said first number (K) of pressure zone set values on the basis of a mathematical model of the adjustable nip so that the deviation of the pressure profile or transverse pressure distribution applied to the web passing through the nip from the setting zone set value profile or distribution is substantially minimized.