Method for measuring and controlling digester or impregnation vessel chip level by means of measuring chip pressure

(19)

(11)

EP 2 085 509 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	29.12.2010 Bulletin 2010/52

(43)	Date of publication A2:
	05.08.2009 Bulletin 2009/32

(21)	Application number: 08011872.2

(22)	Date of filing: 01.07.2008

(51)

International Patent Classification (IPC):

D21C 7/12^(2006.01)

D21B 1/34^(2006.01)

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
	Designated Extension States:
	AL BA MK RS

(30)

Priority:

30.01.2008 US 24654 P
22.04.2008 US 107179

(71)	Applicant: Andritz, Inc.
	Glens Falls, NY 12801-3636 (US)

(72)	Inventor:
	Tuuri, Sami Helsinki 11610 (FI)

(74)	Representative: HOFFMANN EITLE
	Patent- und Rechtsanwälte Arabellastraße 4 81925 München 81925 München (DE)

(54)	Method for measuring and controlling digester or impregnation vessel chip level by means of measuring chip pressure

(57) A method and system for determining chip pressure in a vessel (10) containing a slurry of lignocellulosic material including: sensing a total static pressure of the slurry in the vessel (10); sensing a hydrostatic pressure of the liquor in the vessel (10), and determining the chip pressure based on a difference of the sensed total static pressure of the slurry and the sensed hydrostatic pressure of the liquor.

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