Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
  • G01N11/02—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material
  • G01N11/04—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
  • G01N11/06—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture by timing the outflow of a known quantity

Definitions

• the present invention relates to a process for determination of the viscosity of l iquids and more spesifical l y the continuous process for this determination , as wel l as a device for carrying out this process .
• the viscosity of liquids is normal ly determined by means of one of the fol lowing main types of device :
• Capillary viscometri is based on measurement of the flow velocity for a certain known volume of the liquid, flowing freely through a given capillary under well defined, standardized conditions. In practice this is given as the volume present between two given marked levels in the inlet part of the capillary. The time used for the surface of the liquid to pass between these two levels is thereby at the same time identical with the efflux time for an equivalent liquid volume passing through the capillary.
• capillary viscometri is based on the use of a stop watch and visual judgement of the liquid surface passing the level marks.
• Automation of the method has comprised substituting this visually/manually determined time measurement by the use of optical or electrical (conductance) sensors.
• optical or electrical (conductance) sensors are commercially available.
• Viscosity is an important product parameter within the pulp industry. Samples of chemical pulp (bleached cellulose) is then dissolved in for example cupriethylenediamine (CED) or cuprammonium, and the viscosity of the resulting liquid will be among the qualities used to characterize the pulp. Within the Nordic pulp industry the method SCAN-C 15:62 is used for this analysis. Later this method is mainly accepted and used by ISO as ISO 5351/1-1981. A few years ago SCA Control Systems AB, Sundsvall, Sweden, introduced a viscosity analyzer "Viscomat 320 20" for this quality control analysis. Even this advanced analytical equipment, reported to be the result of considerable research and development, is based on the samples being sucked up into/flowing out of capillaries with fused-in platinum electrodes.
• CED cupriethylenediamine
• Fig. 1 shows a device for carrying out the process
• FIG. 2 and 3 show graphically a comparison of results obtained by following the present process with results according to the use of standard method.
• Fig. 4 shows another modification of the device shown in Figure 1.
• a device for carrying out the process comprises a capillary shown inside a jacket 1 through which for example water at a certain temperature can be added through the pipe stub 2 and let out through the pipe stub 3.
• the capillary has an extended part 4 to which the liquid is introduced by means of a pump and by a tube 1.
• the liquid is introduced into the expanded part 4 in an amount exceeding the amount of liquid flowing out through the capillary.
• Excess of liquor is extracted by means of a pump through tube 6 in such a way that a constant liquid level is maintained within the expanded part of the capillary.
• the liquid flows out through the lower end 7 of the capillary leaving in the form of drops 8.
• the lower end of the capillary is located within a drop counting device generally named 9 containing a device to show or register the drops.
• the device 9 comprises a light source, which can be a photo diode, as well as a photo detector which is connected to an electronic counting device or a time measuring device.
• liquid When the sample liquid is introduced through the tube 5, liquid will build up in the capillary itself and in the expanded part of it and reach the extraction tube 6, and drops will start falling from the lower end 7 of the capillary.
• the falling drops will pass through the light beam from the photo diode in such a way that the passing of the drops will be detected by the photo detector and registered by the electronic counting device.
• the liquid flow out from the capillary depends upon the viscosity of the liquid, and consequently the number of drops per unit of time will be a measure for the viscosity of the liquid.
• the time between the drops can be calculated consecutively, preferably by counting drops and measuring the time for a certain number of drops, followed by the calculation of an average for the time between two succeeding drops.
• the device according to Figure 4 is equipped with a Mariotte flask, in such a way that the pressure can be varied.
• the additional device comprises a vessel 10, a connection tube 11 and a close cap 12 through which the tubes 5 and 6 are mounted in an airtight way.
• a sliding tube 13 Down into the vessel 10 a sliding tube 13 is introduced, the position of which, below the liquid surface 14, can be adjusted.
• the tube 13 into the liquid By adjusting the tube 13 into the liquid in this manner, the pressure in the system can be reduced by h mm liquid column. This is an advantage because when shifting to another viscosity range, one will be able to operate in approximately the same range of linear flow through the capillary.
• the drops can for example be detected and counted by hitting a small microphone, passing between two electronic tips or any device that can register a falling drop.
• the intrinsic viscosity determined and calculated as cm 3 /g according to SCAN-C 15, is shown versus sec/drop according to the device in Figure 1, for a series of cellulose pulps under the following conditions:
• x-axis The pulp dissolved in CED, adapted to 0,6 mm capillary with drop counting and time measurement according to Fig. 1.

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• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Sampling And Sample Adjustment (AREA)
• Detergent Compositions (AREA)
• Investigating Or Analysing Biological Materials (AREA)
• Automatic Analysis And Handling Materials Therefor (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)

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Applications Claiming Priority (2)

Publications (1)

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ID=19888403

Family Applications (1)

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Cited By (4)

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Citations (2)

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• 1985
  • 1985-07-23 NO NO852934A patent/NO159753C/no unknown
• 1986
  • 1986-06-23 JP JP61503540A patent/JPS62502777A/ja active Pending
  • 1986-06-23 FI FI871233A patent/FI871233L/fi not_active Application Discontinuation
  • 1986-06-23 DE DE19863690367 patent/DE3690367T1/de not_active Ceased
  • 1986-06-23 GB GB08703098A patent/GB2185325A/en not_active Withdrawn
  • 1986-06-23 WO PCT/NO1986/000043 patent/WO1987000626A1/en active Application Filing
• 1987
  • 1987-02-20 SE SE8700697A patent/SE8700697D0/xx not_active Application Discontinuation

Patent Citations (2)

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