| US 7,540,937 B2 | ||
| Method for continuous cooking | ||
| Vidar Snekkenes, Karlstad (Sweden); Lennart Gustavsson, Karlstad (Sweden); and Jonas Saetherasen, Karlstad (Sweden) | ||
| Assigned to Metso Fiber Karlstad AB, Karlstad (Sweden) | ||
| Filed on Jan. 19, 2005, as Appl. No. 11/38,704. | ||
| Claims priority of application No. 0400253 (SE), filed on Feb. 09, 2004. | ||
| Prior Publication US 2005/0173081 A1, Aug. 11, 2005 | ||
| Int. Cl. D21C 11/00 (2006.01); D21C 11/06 (2006.01) | ||
| U.S. Cl. 162—29 [162/47] | 8 Claims |
| 8. A method for the continuous cooking of cellulose pulp, comprising:
providing an impregnation vessel in fluid communication with a digester,
feeding a mixture of chips and process fluid to the impregnation vessel,
feeding the impregnated chips together with a circulation fluid through a transfer line to a top separator on the digester,
cooking the chips in the digester,
withdrawing a fraction of the circulation fluid at the top separator,
returning the fraction of the circulation fluid to a bottom of the impregnation vessel via a return line,
withdrawing black liquor from the digester at a withdrawal location to a black liquor line,
providing a heat exchanger in direct operative engagement with both the return line and the black liquor line for exchanging
heat between the return line and the black liquor line, the heat exchanger cooling the black liquor in the black liquor line
after passing through the heat exchanger,
the heat exchanger heating the circulation fluid in the return line, and
leading the black liquor in the black liquor line to an upper section of the impregnation vessel after passing through the
heat exchanger.
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