Method and system for analyzing solid matter containing liquids and monitoring or controlling processes containing such liquids

Patent metadata

Field	Value
Publication number	US-10139330-B2
Application number	US-201314403579-A
Country	US
Kind code	B2
Filing date	May 24, 2013
Priority date	May 25, 2012
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

The invention concerns a method and system for analyzing a liquid sample containing solid matter. The method comprises fractionating the sample according to particle sizes and/or masses of the solid matter so as to produce sample fractions, and measuring at least one physical or chemical property of at least one of said sample fractions. According to the invention the sample is conducted to a disintegration channel having one or more depressions, and a liquid flow having a non-constant temporal velocity profile is applied through the disintegration channel, in order to gradually take solid matter of the sample with the liquid flow from said one or more depressions for providing said sample fractions. The invention allows for efficient fractionation of samples, which cannot be fractionated using conventional field flow fractionation, for example.

First claim

The invention claimed is:

1. A method of analyzing a liquid sample containing solid particles, the method comprising:
fractionating the sample according to particle sizes and/or masses of the solid particles, so as to produce sample fractions, by
conducting the sample to a disintegration channel having depressions to retain the sample in said depressions, and a through-flow zone,
applying a liquid flow having a non-constant temporal velocity profile through the disintegration channel, in order to gradually release solid particles of the sample with the liquid flow from said depressions to the through-flow zone in the disintegration channel, wherein the liquid flow is applied at a velocity producing hydrodynamic shear on the sample when interacting with said depressions, to disintegrate flocks in the sample retained in said depressions, and

measuring at least one physical or chemical property of at least one of said sample fractions.

2. The method according to claim 1 , wherein the particles of the sample are gradually released with the liquid flow from said depressions as the flow velocity is varied.

3. The method according to claim 1 , wherein the liquid flow and the depressions cause the hydrodynamic shear on the sample.

4. The method according to claim 1 , wherein the number of depressions in said disintegration channel is at least 2.

5. The method according to claim 1 , wherein said fractionation is a continuous process and said measuring is carried out on-line while the fractionation proceeds.

6. The method according to claim 1 , wherein the solid particles in the sample have a tendency to flocculate mechanically or chemically.

7. The method according to claim 1 , wherein the sample is conducted to the disintegration channel at a velocity which causes initial disintegration of sample due to shear forces.

8. The method according to claim 1 , wherein after conducting the sample to the disintegration channel, sample flow is stopped before applying the liquid flow.

9. The method according to claim 1 , wherein the velocity profile comprises at least one profile part with a gradually or stepwise increasing temporal velocity as a function of time, the highest flow velocity in said profile part being at least 5 times higher than the lowest flow velocity in said profile part.

10. The method according to claim 1 , wherein the liquid flow, with particles taken from the disintegration channel, is conducted from the disintegration channel to a field flow fractionation (FFF) channel.

11. The method according to claim 1 , wherein the liquid flow is conducted from the disintegration channel to a homogenizer channel having an average diameter larger than the average diameter of the disintegration channel.

12. The method according to claim 1 , wherein said measuring of at least one physical or chemical property comprises measuring the turbidity, hydrophobicity of at least one of the sample fractions, particle size of the sample fractions and/or optical response of the solid particles in at least one of the sample fractions, or obtaining an image of at least one of the sample fractions.

13. The method according to claim 1 , wherein the sample suspension is a raw or treated pulp sample or filtrate.

14. The method according to claim 1 , wherein it is automatically carried out for on-line monitoring purposes for samples sequentially taken from a suspension of pulp-making process, paper or cardboard-making process, wastewater treatment process, desalination process, membrane process, or oil or mining process, or controlling of such processes.

15. A system for measuring sample suspensions containing solid particles of different sizes, the system comprising:
means for providing a sample suspension,
a disintegration channel, having
a through-flow zone,
depressions to retain the sample in said depressions, and
a means for applying a liquid flow through the disintegration channel at a velocity producing hydrodynamic shear on the sample when interacting with said depressions, to disintegrate flocks in the sample retained in said depressions and to raise particles from the depressions to the through-flow zone in the disintegration channel, for fractionating the sample suspension according to particle sizes and/or masses so as to produce sample fractions, and

means for measuring at least one physical or chemical property of at least some of the sample fractions.

16. The system according to claim 15 , wherein the depressions are each formed by widenings and preceding and following narrowings in the cross-sectional area of the disintegration channel, along the flow direction.

17. The system according to claim 15 , wherein the depressions are at least partly defined by walls in the disintegration channel.

18. The system according to claim 15 , further comprising means for conducting the sample to the disintegration channel at a velocity which causes a temporally unsteady flow of sample.

19. The system according to claim 15 , wherein the means for applying the liquid flow is to feed the liquid flow with a non-constant temporal velocity profile.

20. The system according to claim 15 , further comprising a field flow fractionation (FFF) channel coupled in sequence with the disintegration channel for further fractionation of the sample.

21. The system according to claim 15 , wherein the number of depressions in said disintegration channel is at least 2.

Assignees

• Kemira Oyj

Inventors

• Vähäsalo Lari
• Saari Eija
• Joensuu Iiris
• Piironen Marjatta

Classifications

• G01N15/0272 Primary

  with screening; with classification by filtering (B01D takes precedence) · CPC title

• G01N30/0005 Primary

  Field flow fractionation · CPC title

• G01N2015/0053

  in liquids, e.g. trouble · CPC title

• G01N2015/0288

  Sorting the particles · CPC title

• G01N15/06 Primary

  Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) · CPC title