APPARATUS FOR DELIVERING A FLUID SUSPENSION TO A FORMING UNIT

• US 3,802,966 A
• Filed: 04/17/1972
• Issued: 04/09/1974
• Est. Priority Date: 08/22/1969
• Status: Expired due to Term

• Current Assignee: Karl H. Smith, Paul J. Delekto, William H. Mehaffey
• Original Assignee: Karl H. Smith, Paul J. Delekto, William H. Mehaffey
• Inventors: Delekto, Paul J., Mehaffey, William H., Smith, Karl H.
• Primary Examiner(s): Bashore, S. Leon
• Assistant Examiner(s): D'Andrea, Jr., Alfred
• Application Number:
  US05/244,591
• Time in Patent Office: 722 Days
• Field of Search: 162/336,338,343,203,303,345
• US Class Current: 162/343
• CPC Class Codes: D21F 1/02 Head boxes of Fourdrinier machines
• CPC Class Codes: D21F 1/024 Details of the feed chamber
• CPC Class Codes: D21F 1/026 Details of the turbulence section
• CPC Class Codes: D21F 1/028 Details of the nozzle section

Abstract

This disclosure relates to flowboxes including headboxes and other apparatus for delivering solid-containing suspensions to forming units of papermaking or similar machines. The flowbox receives the suspension from a supply conduit and delivers it to the forming unit as a jet having the desired configuration, required speed and adequate distribution of solids by employing a controlled flow pattern through the flowbox. Preferably two banks of elongated channels having varying cross sections are positioned in the flowbox to provide a plurality of streams discharging from each bank which intercept at an acute angle and merge together within a discharge passageway to form a single jet which is discharged to the forming unit.

Claims

1. In a headbox apparatus for delivering a layer of stock to a forming unit, the combination comprising:

a. means forming a flow divider section;

b. means in said flow divider section dividing said flow divider section into a plurality of banks of flow channels having progressively decreasing cross-sectional areas, said means including a plurality of laterally spaced apart immovable divider vanes within each of said banks of channels, said vanes having generally rectangular crosssections;

c. means forming a discharge passageway connected at its inlet end to the discharge end of said flow divider section; and

d. means forming a supply header connected to the inlet end of said flow divider section for supplying stock thereto, the major axis of said supply header being substantially perpendicular to the direction of flow in said flow channels;

said divider vanes having curved entrance-forming sections to assist the stock in changing direction as it enters said flow channels from said supply header, said banks of channels positioned at acute angles to each other such that they converge towards one another at the discharge end of said flow divider section.

2. The apparatus of claim 1 in which there are only two banks of flow channels.

3. The apparatus of claim 1 wherein the height of said flow channels progressively decreases from the entrance end of said flow divider section to the discharge end of said flow divider section.

4. The apparatus of claim 1 wherein each of said divider vanes in horizontal cross-section is convexly-rounded over its forward portIon, substantially rectangular along its intermediate portion and inwardly tapered over its terminal portion.

5. The apparatus of claim 2 wherein said flow channels in one of said banks of channel are offset from said flow channels in the other bank of channel.

6. The apparatus of claim 2 wherein the height of said flow channels in both said banks of channels progressively decreases from the entrance end of said flow divider section to the discharge end of said flow divider section.

7. The apparatus of claim 2 wherein the height of said flow channels in both said banks of channels progressively decreases from the entrance end of said flow divider section to the discharge end of said flow divider section and wherein said flow channels in one of said banks of channels are offset from said flow channels in the other bank of channels.

8. An apparatus for delivering a solid containing suspension to a forming unit comprising a. an elongated supply header with one end having a cross-sectional area of selected size which end has an inlet opening therein, a plurality of outlets along side portions of the header and an end opposite the first-mentioned end having a cross-sectional area smaller than the first end, the header having its side portions generally tapered along the length of the header such that the cross-sectional area of the header becomes generally smaller as the distance from the inlet is increased and the outlets in the side portions of the header being arranged in at least one pair of banks;

b. at least one pair of banks of elongated channels connected to and communicating with the banks of outlets in the header sides, the banks of channels in each pair of banks of channels i. having means defining a row of channels with curved entrance sections for assisting the suspension in changing its direction of flow as it leaves the header to a direction of flow down the channels without creating substantial turbulence and deposition of solids on the entrance sections;

ii. having said row of channels with outwardly tapered outlet portions so that the outlet portion of each channel is not separated from the outlet portion of adjacent channels;

iii. being spaced apart at the channel inlet ends and being positioned at an acute angle so that the banks of channels converge towards one another and are not spaced apart at the outlet ends and therefore each channel outlet is not separated from the adjacent channel outlet;

c. a discharge passageway positioned with its inlet coterminous with the outlets of said elongated channels for receiving the plurality of streams of suspension from said channels which passageway has a non-expanding generally constant cross-sectional area to maintain a stable flow pattern prior to discharge of the suspension to the forming unit.

9. The apparatus of claim 8 in which the elongated channels have cross sections which are steadily reduced in area throughout a portion of their length, moving in the direction of flow of the suspension.

10. The apparatus of claim 8 in which the elongated channels have rectangular cross sections in which the width increases and the height decreases moving in the direction of flow of the suspension.

11. The apparatus of claim 8 in which there is but one pair of banks of channels.