Method of measuring hydrophobic contaminants in a pulp slurry or a papermaking system

Patent metadata

Field	Value
Publication number	US-10844544-B2
Application number	US-201816196540-A
Country	US
Kind code	B2
Filing date	Nov 20, 2018
Priority date	Nov 21, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A method of measuring hydrophobic contaminants in a pulp slurry or a papermaking system includes the steps of providing an aqueous paper mill sample, filtering the aqueous paper mill sample to produce a filtrate comprising particles, and collecting an image of the particles in a measured volume of the filtrate. The method also includes the steps of analyzing the image to determine a size and morphology of the particles in the measured volume of filtrate, identifying spherical particles having a size of from about 1 micron to about 20 microns in the measured volume of filtrate, and quantifying a number of the spherical particles having the size of from about 1 micron to about 20 microns in the measured volume of filtrate. This method is useful for papermakers for deposition diagnostics, prevention, and contaminant control treatment optimization.

First claim

What is claimed is:

1. A method of measuring hydrophobic contaminants in a pulp slurry or a papermaking system, said method comprising the steps of:
providing an aqueous paper mill sample,
filtering the aqueous paper mill sample to produce a filtrate comprising particles,
collecting an image of the particles in a measured volume of the filtrate,
analyzing the image to determine a size and morphology of the particles in the measured volume of filtrate,
identifying spherical particles having a size of from 1 micron to 10 microns, having a circularity of 0.5 or greater, and having an aspect ratio of 0.7 or greater, in the measured volume of filtrate, and
quantifying a number of the spherical particles having the size of from 1 micron to 10 microns in the measured volume of filtrate.

2. The method of claim 1 wherein the hydrophobic contaminants comprise pitch.

3. The method of claim 2 wherein the spherical particles have an aspect ratio of 0.9 or greater.

4. The method of claim 1 wherein the spherical particles have a circularity of 0.66 or greater.

5. The method of claim 1 wherein the spherical particles have an aspect ratio of 0.9 or greater.

6. The method of claim 1 wherein the size of the spherical particles is from 2 to 5 microns.

7. The method of claim 1 wherein the step of collecting an image is further defined as collecting an image using flow imaging microscopy.

8. The method of claim 1 wherein the spherical particles have a size of 1 to 9 microns, a circularity of 0.66 or greater, an aspect ratio of 0.9 or greater, and a size of about 2 to 5 microns, wherein the circularity is calculated using the formula:
circularity=(4×π×)/perimeter.

9. The method of claim 1 wherein the hydrophobic contaminants comprise pitch, wherein the spherical particles have a circularity of 0.66 or greater, an aspect ratio of 0.9 or greater, and a size of 2 to 5 microns, wherein the circularity is calculated using the formula: circularity=(4×π×area)/perimeter, and wherein the step of collecting an image is further defined as collecting an image using flow imaging microscopy.

10. A method of measuring hydrophobic contaminants in a pulp slurry or a papermaking system, said method comprising the steps of:
providing an aqueous paper mill sample,
filtering the aqueous paper mill sample to produce a filtrate comprising spherical particles having a circularity of 0.66 or greater or an aspect ratio of 0.9 or greater, and also a size of 2 to 5 microns,
collecting an image of the spherical particles in a measured volume of the filtrate,
analyzing the image to determine a size and morphology of the spherical particles in the measured volume of filtrate,
identifying the spherical particles having the size of 2 to about 5 microns, and
quantifying a number of the spherical particles having the size of 2 to 5 microns in the measured volume of filtrate,
wherein the circularity is calculated using the formula: circularity=(4×π×area)/perimeter.

11. A method of controlling hydrophobic contaminants in a pulp slurry or a papermaking process water, said method comprising the steps of:
providing an aqueous paper mill sample,
filtering the aqueous paper mill sample to produce a filtrate comprising particles,
collecting an image of the particles in a measured volume of the filtrate,
analyzing the image to determine a size and morphology of the particles in the measured volume of filtrate,
identifying spherical particles having a size of from about 1 micron to 10 microns, having a circularity of 0.5 or greater, and having an aspect ratio of 0.7 or greater, in the measured volume of filtrate,
quantifying the number of the spherical particles in the measured volume of filtrate, and
adding at least one contaminant control agent to the papermaking system based on the number of spherical particles per a unit volume of filtrate,
wherein the circularity is calculated using the formula: circularity=(4×π×area)/perimeter.

12. The method of claim 11 wherein the contaminant control agent is added in an amount of from 0.5 to 12 lb per ton of dry pulp.

13. The method of claim 11 wherein the contaminant control agent is added in an amount of from 0.5 to 7.0 lb per ton of dry pulp.

14. The method of claim 11 wherein the contaminant control agent comprises a dispersing agent.

15. The method of claim 11 wherein the contaminant control agent comprises a fixative agent.

16. The method of claim 11 wherein the hydrophobic contaminants comprise pitch.

17. The method of claim 11 wherein the hydrophobic contaminants comprise pitch and the spherical particles have a circularity of 0.66 or greater.

18. The method of claim 11 wherein the spherical particles have an aspect ratio of 0.9 or greater.

19. The method of claim 11 wherein the step of collecting an image is further defined as collecting an image using flow imaging microscopy.

20. The method of claim 11 wherein the spherical particles have a circularity of 0.66 or greater, an aspect ratio of 0.9 or greater, and a size of 2 to 5 microns, wherein the circularity is calculated using the formula: circularity=(4×π×area)/perimeter.

Assignees

• Solenis Tech Lp

Inventors

• Sharoyan Davit E
• Zhang Fushan
• Barrett Matthew John

Classifications

• D21H23/78

  Controlling or regulating not limited to any particular process or apparatus · CPC title

• G06T2207/10056

  Microscopic image · CPC title

• G06T7/62

  of area, perimeter, diameter or volume · CPC title

• G06T2207/30124

  Fabrics; Textile; Paper · CPC title

• D21H21/02 Primary

  Agents for preventing deposition on the paper mill equipment, e.g. pitch or slime control (removal of fats, resins, pitch, or waxes D21C9/08) · CPC title