Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N15/06—Investigating concentration of particle suspensions
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N2015/0042—Investigating dispersion of solids
  • G01N2015/0053—Investigating dispersion of solids in liquids, e.g. trouble
  • G01N2015/0057—Investigating dispersion of solids in liquids, e.g. trouble of filaments in liquids

Definitions

• the present invention relates to a concentration sensor for fibre suspensions to be used in a closed system either connected to the side of a pipe in which a fibre suspension is streaming or to the wall of a container close to its bottom.
• Concentration sensors for fibre suspensions in open systems are often based on the principal that one measures the torque that is required to rotate a sensor by means of a motor force in an almost still standing or slowly streaming fibre suspension. If one wants to carry out the measuring in the same way in a closed pipe system, one will face the problem that the suspension has such a high speed passing the rotating sensor that any distinct measure value is not obtained. One has then improved the system by bulging the pipe which results in lower streaming velocity and one has then arranged the sensor in a niche or bulged part of the pipe. This is shown in the Swedish patent 300 356.
• the object of the present invention is to bring about a concentration sensor mounted in a closed system for flowing fibre suspensions, which sensor is unsensible for irregularities in the movements of the suspension.
• This has been solved from a starting point that one in a known way arranges the sensor in a niche 2, which has an open connection to the pipe 1 where the fibre suspension flows forwardly.
• a stirrer 3 has been mounted on a motor driven shaft 5, which at rotation can bring the suspension within the niche to a rotating whirl.
• Behind the stirrer in the niche immersed in the whirl a sensor 4 has been arranged. This sensor is influenced by a torque from the rotating suspension.
• this sensor has been mounted on a shaft 6 which protrudes out through an elastic rubber bushing in the bottom of the niche. At the outer side of the niche the shaft is carried by a friction free arrangement 8. Between this and the bottom of the niche an arm 9, on which the torque shall be measured, has been arranged.
• the sensor may be given different shapes dependent on the properties of the fibre suspension. For instance pine sulphate- fir sulphite or suspensions of ground pulp do not have the same characters which is shown in the attached sheet of diagrams. Therefore the sensor must experimentically be developed for each type of suspension. This means that one can not show any certain shape of the sensor, but only give examples on possible shapes.
• Fig. 1 and Fig. 5 show an excentrically shaped sensor having pins which allow space for the shaft of the stirrer.
• Fig. 3 shows a centrically arranged sensor which can be suitable when the shaft of the stirrer comes into the niche coaxially with the shaft of the sensor but from opposite direction.
• Fig. 6 shows a sensor 4 arranged centrally in the niche and suspended on three pins 12. A ring 16 around the niche is connected to the sensor by means of these three pins which protrudes radially out through elastic rubber bushings 14 in the wall of the niche. The pins have been pivotably connected to the ring 16 and the sensor 4.
• Fig. 2 shows where the measuring power P can attack the arm 9.
• Fig. 4 shows the concentration sensor mounted on a container for fibre suspensions.
• the driving motor 11 for the stirrer is suitably speed variable.

Landscapes

• Chemical & Material Sciences (AREA)
• Biochemistry (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Analytical Chemistry (AREA)
• Dispersion Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Mixers Of The Rotary Stirring Type (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20376962

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (4)

• 1989
  • 1989-09-25 SE SE8903136A patent/SE8903136L/ not_active Application Discontinuation
• 1990
  • 1990-09-24 WO PCT/SE1990/000606 patent/WO1991004480A1/en active Application Filing
  • 1990-09-24 DE DE19904091583 patent/DE4091583T/de not_active Withdrawn

Patent Citations (4)

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