Method for feeding comminuted fibrous material
US6106668A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Apr 21, 2018 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C7/06
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A system and method for feeding comminuted cellulosic fibrous material such as wood chips to the top of a treatment vessel such as a continuous digester provide enhanced simplicity, operability, and maintainability by eliminating the high pressure transfer device conventionally used in the prior art. Instead of a high pressure transfer device the steamed and slurried chips are pressurized using one or more slurry pumps located at least thirty feet below the top of the treatment vessel and for pressurizing the slurry to a pressure of at least about 10 bar gauge. A return line from the top of the digester may, but need not necessarily, be operatively connected to the one or more pumps and if connected to the pumps the pressure in the return line may be reduced utilizing a pressure reduction valve and/or a flash tank. During pressurized transferring of the slurry from the pumps to a treatment vessel (which may be as little about 10 feet or as much as about a half a mile away) treatment liquid is provided which contains at least some active pumping chemical including sodium hydroxide, sodium sulfide; polysulfide, anthraquinone or their equivalents or derivatives; surfactants, enzymes, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.