Expanded flow range edge flow control valve for use in a paper machine headbox

(19)

(11)

EP 0 936 303 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	02.08.2000 Bulletin 2000/31

(43)	Date of publication A2:
	18.08.1999 Bulletin 1999/33

(21)	Application number: 99630015.8

(22)	Date of filing: 05.02.1999

(51)	International Patent Classification (IPC)⁷: D21F 1/02, D21F 1/06

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

10.02.1998 US 21246

(71)	Applicant: BELOIT TECHNOLOGIES, INC.
	Wilmington, Delaware 19803 (US)

(72)	Inventor:
	Neill, Eugene Bruce So. Beloit, Illinois 61080 (US)

(74)	Representative: Schmitz, Jean-Marie et al
	Dennemeyer & Associates Sàrl P.O. Box 1502 1015 Luxembourg 1015 Luxembourg (LU)

(54)	Expanded flow range edge flow control valve for use in a paper machine headbox

(57) Edge flow control valves located within edge flow tubes of a tube bank in a headbox can be adjusted to optimize fiber orientation of paper produced in a papermaking process. The present invention uses a chamfer at the inlet of edge flow tubes in order to increase maximum flow of pulp through the edge tube and edge valve. The minimum flow range is not changed, therefore, the essential flow range of pulp through the edge flow valve is increased. Laboratory tests have shown at least a 15 percent increase in maximum flow while not changing the minimum flow. Using a chamfer tool with a stop collar to control the depth of the cut, a chamfer is provided at the inlet of each edge flow tube for optimum performance. According to the present invention, paper produced in a papermaking process will have an improved fiber orientation when more flow at the edges of a headbox is needed.

Search report