On-line apparatus for determining degree of completion of pulp cook
US4752357A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1986 |
| Grant date | Jun 21, 1988 |
| Priority date | — |
| Expiry date | Dec 22, 2006 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C3/228
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and suitable apparatus for periodically analyzing pulp stock, including wood pulp and water, in a pulp digester, which may or may not be part of a paper machine, to determine the amount of cooking to which the pulp has been subjected. The method includes diluting a sample of the pulp stock from the digester, diluting the sample to a predetermined range of consistency, and determining the exact consistency of the sample. Consistency can be determined by any suitable commercially available apparatus. Next, substantially all the water is removed from the sample. A reagent, preferably a 14 percent solution of nitric acid in water, is then added to the sample and allowed to react with the sample for a predetermined time interval at a predetermined temperature. The light absorbance of the reagent during and after the reaction is determined by the amount of cooking to which the pulp has been subjected and the consistency of the sample. Finally the reagent is removed from the sample and examined, such as by use of a colorimeter, to determine the light absorbance of the reagent. The amount of cooking is then determined from a known relationship thereof to the light absorbance of th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.