Claims
- 1. A headbox device for a papermaking machine and having a predetermined direction of flow for a fiber stock suspension passing through the headbox device, comprising:
- a distribution box;
- a nozzle chamber;
- a guide device for conducting the fiber stock suspension in said predetermined direction of flow and serving for distributing the fiber stock suspension across the width of the papermaking machine;
- said guide device being located subsequent to said distribution box as seen in said predetermined direction of flow of the fiber stock suspension;
- said guide device flow communicating with said nozzle chamber;
- said nozzle chamber comprising two lip members defining a slice opening leading to the papermaking machine;
- at least one of said two lip members of said nozzle chamber comprising at least two sections with substantially different convergence angles relative to said predetermined direction of flow of the fiber stock suspension;
- at least one section of said at least two sections being connected directly subsequently to said guide device and having a first convergence angle of said substantially different convergence angles;
- said at least one section of said one lip member defining a quieting zone for substantially equalizing flow velocities of the fiber stock suspension;
- at least one further section of said at least two sections lying directly prior to said slice opening of said nozzle chamber and having a second convergence angle of said substantially different convergence angles;
- said at least one further section defining an acceleration zone for abruptly accelerating the fiber stock suspension;
- said at least one section having a length which is a multiple of the length of said at least one further section;
- said first convergence angle lying between 0.degree. and 30.degree.; and
- said second convergence angle lying between 60.degree. and 90.degree..
- 2. The headbox device as defined in claim 1, wherein:
- the length of said at least one section is at least four times as great as the length of said at least one further section.
- 3. The headbox device as defined in claim 1, wherein:
- said slice opening has a predetermined slice width; and
- the length of said at least one further section being greater than said predetermined slice width of said slice opening.
- 4. The headbox device as defined in claim 3, further including:
- a slice shutter mounted at the at least one further section, which has said convergence angle in the range of 60.degree. to 90.degree., in the region of the slice opening and having a predeterminate degree of advance; and
- said slice shutter being displaceable such that said predeterminate degree of advance of said slice shutter is adjustable in a range lying between 0.05 and 0.5 times said predetermined slice width of said slice opening.
- 5. The headbox device as defined in claim 1, wherein:
- at least one of said at least one section and said at least one further section respectively extending at said first convergence angle between 0.degree. and 30.degree. and said second convergence angle in the range of 60.degree. to 90.degree., extends at a convergence angle which continuously increases within the respective convergence angle range in said nozzle chamber in said predetermined direction of flow of the fiber stock suspension.
- 6. The headbox device as defined in claim 1, wherein:
- at least one of said at least one section and said at least one further section is pivotably mounted.
- 7. The headbox device as defined in claim 1, wherein:
- at least one of said at least one section and said at least one further section is displaceably mounted.
- 8. A headbox device for a papermaking machine and having a predetermined direction of flow for a fiber stock suspension passing through the headbox device, comprising:
- means defining a nozzle chamber through which the fiber stock suspension is passed from the headbox to the papermaking machine;
- said nozzle chamber comprising two lip members defining a slice opening for the outflow of the fiber stock suspension;
- at least one of said two lip members of said nozzle chamber comprising at least two sections with substantially different angles of inclination converging with respect to said predetermined direction of flow of the fiber stock suspension;
- at least one section of said at least two sections having a first converging inclination angle of said substantially different converging inclination angles;
- said first converging inclination angle lying between 0.degree. and 30.degree.;
- said at least one section bounding a quieting zone for substantially equalizing flow velocities of the fiber stock suspension;
- at least one further section of said at least two sections having a second converging inclination angle of said substantially different converging inclination angles;
- said at least one further section bounding an acceleration zone for abruptly accelerating the fiber stock suspension;
- said second converging inclination angle lying between 60.degree. and 90.degree.;
- said at least one section having said first converging inclination angle being located on an inlet side of said nozzle chamber;
- said at least one further section being located substantially immediately upstream of and in close proximity to said slice opening as viewed in said predetermined direction of flow of said fiber stock suspension; and
- said at least one section having a length which is greater than the length of said at least one further section.
- 9. The headbox device as defined in claim 8, wherein:
- said second converging inclination angle of said acceleration zone is of a magnitude sufficient for producing shear forces for disintegrating floccules present in the fiber stock suspension.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3045/85 |
Jul 1985 |
CHX |
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of the commonly assigned, co-pending U.S. Pat. Application Ser. No. 06/880,544, filed on Jun. 30, 1986, entitled "HEADBOX DEVICE FOR A PAPERMAKING MACHINE", now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (5)
Number |
Date |
Country |
2852564 |
Jun 1979 |
DEX |
1396309 |
Mar 1965 |
FRX |
1494138 |
Jul 1967 |
FRX |
964044 |
Oct 1982 |
SUX |
733441 |
Jul 1955 |
GBX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
880544 |
Jun 1986 |
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