Method for controlling feed of foamed fiber slurries
US4764253A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1986 |
| Grant date | Aug 16, 1988 |
| Priority date | — |
| Expiry date | Jan 6, 2006 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F11/002
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In a papermaking or like operation wherein fibers are supplied to a headbox in a foamed furnish, a method of controlling furnish flow including the steps of controllably advancing the furnish along a flow path to the headbox, measuring the volume flow rate of furnish through a fixed cross-sectional area in the path with a magnetic flowmeter, combining the flow rate measurement at least with measured values of furnish density and pressure in the path and with a reference pressure value to obtain a corrected volume flow rate value, and controlling the advance of furnish in the path upon departure of this corrected value from a desired value so as to change the corrected value toward the desired value. A temperature measurement can also be combined with the other measured values, and with a reference temperature value, in obtaining the corrected flow rate value. If the headbox has a variable slice opening, a measured value of slice opening dimension can be combined with the corrected volume flow rate value to ascertain the discharge velocity of the furnish issuing from the headbox, and the control of furnish advance can be made responsive to departure of this ascertained velocity from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.