Control of dilution lines in a dilution headbox of a paper making machine
US5549793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1994 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Aug 2, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K7/07
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Pinch valves having a flexible, constrictable sleeve are used to control a dilution headbox for a paper making machine. A variety of pinch valves may be used in the present invention with the pinch valves being actuated by pneumatic or hydraulic pressure or by mechanically pinching the valves' sleeves by means of rams driven by stepper or linear drive motors. For pneumatic control, dynamic differential pressure drops are measured across the valves to determine flow rate through the valves. A pinch valve, referred to herein as a torsional pinch valve, is disclosed for dilution headbox control. In one form, a first end of a sleeve is fixedly mounted in a support frame and the second end of the sleeve is mounted for rotation in the frame. A driver rotates the second end of the sleeve such that a flow path through the sleeve is controlled. The flow path is a maximum when no torsion is placed on the sleeve and is reduced to substantially zero by sufficient rotation. In another form, first ends of two sleeves are secured into a support frame such that the sleeves are in axial alignment with one another. The second ends of the sleeves are secured to an annular collar or sleeve support mem…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.