Apparatus and method for processing white water in a paper machine

• US 10,550,517 B2
• Filed: 05/26/2016
• Issued: 02/04/2020
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Valmet AB (Valmet Oyj)
• Original Assignee: Valmet AB (Valmet Oyj)
• Inventors: Engqvist, Elin, Videgren, Leif
• Primary Examiner(s): Halpern, Mark
• Application Number:
  US15/577,211
• Publication Number:
  US 20180171554A1
• Time in Patent Office: 1,349 Days
• Field of Search: 162190
• CPC Class Codes: D21D 5/26 De-aeration of paper stock
• CPC Class Codes: D21F 1/66 Pulp catching, de-watering, or recovering; Re-use of pulp-water

Abstract

Aspects provide for a Whitewater processing system suitable for managing an ejected Whitewater spray during operation of a paper or board making machine. A de-air system may provide for improved removal of air from the Whitewater. A calming system may reduce turbulence in a liquid flow, reducing turbulence in the flume. The de-air system and calming system may be disposed together or separately. Certain aspects may be implemented with a turbine (e.g., used to generate electricity from the Whitewater spray). Some aspects may provide for improved handling of variable spray velocities.

Claims

1. A calming station configured for use with a forming section of a paper machine to reduce turbulence in a liquid flowing from the forming section into a flume of the paper machine, the calming station comprising:

a liquid inlet configured to receive the liquid;

a liquid outlet configured to convey the liquid out of the calming station; and

a gate through and/or around which the liquid may flow, the gate having a pattern of one or more holes, bars, slats, ridges, and/or grooves, configured to modify the flow of liquid through and/or around the gate, the gate comprising least one of;

an adjustable gate configurable among two or more different positions that alter the flow of the liquid in different ways; and

a first portion having a first pattern of one or more holes, bars, slats, ridges, and grooves, and a second portion having a second pattern of one or more holes, bars, slats, ridges, and grooves different than the first pattern.

2. The calming station of claim 1, wherein the gate comprises the adjustable gate, and the adjustable gate has the first portion having the first pattern and the second portion having the second pattern.

3. The calming station of claim 1, wherein the pattern of one or more holes, bars, slats, ridges, and/or grooves includes a pitch in a fluid flow direction with respect to the gate, and the gate has:

a first portion having a first pitch, and

a second portion having a second pitch.

4. The calming station of claim 1, wherein the pattern comprises an adjustable pattern.

5. The calming station of claim 4, wherein the adjustable pattern comprises one or more slats having an adjustable pitch.

6. The calming station of claim 1, wherein at least one gate comprises a pattern of one or more holes, bars, slats, ridges, and/or grooves that varies over a vertical distance.

7. The calming station of claim 1, further comprising:

a baffle proximate to a bottom of the calming station, at least a portion of the baffle shaped to redirect a flow of water into, within, and/or out of the calming station; and

at least one cleanout disposed proximate to the bottom of the calming station and sealably openable to extract material from the calming station.

8. The calming station of claim 7, wherein the cleanout is coupled to a tube disposed in a region expected to form an eddy during operation of the calming station.

9. The calming station of claim 1, further comprising:

a first gate having the adjustable gate; and

a second gate comprising the first and second portions.

10. The calming station of claim 1, further comprising a de-air system for processing a whitewater spray ejected from a forming wire in the forming section, the de-air system being disposed between the forming wire and the calming station, the de-air system comprising:

channels defined by walls shaped to direct a portion of the whitewater spray away from the machine direction, the channels open at first entrances proximate to the forming wire and terminating at liquid outlets proximate to the liquid inlet of the calming station and defined at least in part by one or more terminal edges; and

air outlets providing for air evacuation from the channels;

wherein, between the respective first entrances and liquid outlets of the de-air system, and excluding the air outlets, there is no substantial fluid communication between the channels.

11. The calming station of claim 1, further comprising a de-air system for processing a whitewater spray ejected from a forming wire in the forming section, the de-air system disposed between the forming wire and the calming station, the de-air system comprising:

channels defined by walls shaped to direct a portion of the whitewater spray away from the machine direction, the channels open at first entrances proximate to the forming wire and terminating at liquid outlets proximate to the liquid inlet of the calming station and defined at least in part by one or more terminal edges; and

air outlets providing for air evacuation from the channels,

wherein

the walls comprise side walls for which a majority of the side walls is within 10 degrees of vertical.

12. A paper machine comprising the calming station of claim 11.

13. The calming station of claim 1, further comprising a de-air system for processing a whitewater spray elected from a forming wire in the forming section, the de-air system disposed between the forming wire and the calming station, the de-air system comprising:

channels defined by walls shaped to direct a portion of the whitewater spray away from the machine direction, the channels open at first entrances proximate to the forming wire and terminating at liquid outlets proximate to the liquid inlet of the calming station and defined at least in part by one or more terminal edges; and

air outlets providing for air evacuation from the channels,

wherein less than 5% of a cross sectional area of the channels is intersected by a free upstream end of a part.

14. A paper machine comprising the calming station of claim 13.

15. The calming station of claim 1, wherein the gate comprises the adjustable gate.

16. The calming station of claim 1, wherein the gate comprises the first and second portions.

17. A paper machine comprising the calming station of claim 10, wherein the air outlets are disposed outside a frame of the paper machine.

18. The paper machine of claim 17, wherein an inner portion of the de-air system is disposed inside the frame of the paper machine, and an outer portion comprising the liquid outlets of the de-air system is disposed outside the frame.

19. A method for managing a flow of liquid water into a flume of a paper machine, the method comprising the steps of:

providing a calming station according to claim 1, the liquid outlet of the calming station being coupled to the flume; and

reducing a turbulence in the flow of liquid water into the flume with the calming station.