Method and apparatus in a paper or board machine for confining pulp flow from the headbox

Abstract

A method in a paper or board machine for confining a pulp flow coming from the headbox (1), in which by at least one deckle part (2) being above the wire in the operating position the pulp flow coming from the headbox is confined in the lateral direction in the edge area of the wire (3). In the method, by a support part (50) impervious to liquid being below the wire (3) together with the deckle part (2) into connection with which liquid is brought, a pressure effect is provided which furthers the sealing between the deckle board (2) and the wire (3) and intensifies the lubrication of at least one sealing surface of the deckle (2). The invention also relates to an apparatus.

Description

BACKGROUND OF INVENTION [0001]The invention relates to a method according to the preamble of claim 1 in a paper or board machine for confining a pulp flow coming from the headbox, in which by at least one deckle part being above the wire in the operating position the pulp flow coming from the headbox is confined in the lateral direction in the edge area of the wire.[0002]The invention also relates to an apparatus according to the preamble of claim 11 in a paper or board machine for confining a pulp flow coming from the headbox, which apparatus comprises at least one deckle part being above the wire which in the operating position is arranged to confine the pulp flow coming from the headbox in the lateral direction in the edge area of the wire.[0003]The apparatus being the object of the invention is typically referred to as a deckle. Its function is to confine the flow of stock discharged from a slice of the headbox onto the wire in the lateral direction on the edges of the wire. The...

AI Technical Summary

Benefits of technology

[0009]The arrangement according to the invention has numerous significant advantages. By the support part impervious to liquid being below the wire together with the deckle into connection with which liquid is brought, a pressure effect is provided which furthers the sealing between the deckle board and the wire and intensifies the lubrication of at least one sealing surface of the deckle. Then, it has been possible to reduce or even completely prevent the formation of edge undulations and to reduce the range of basis weight variation in the edge area of the machine. Correspondingly, it has been possible to make the width of the edge area of reduced basis weight narrower. The runnability of the machine is improved and the width of the pulp web can be increased, whereby productivity is impr

Problems solved by technology

After the stock has advanced through some distance on the wire in the machine direction and a sufficient volume of water has been removed from it, this problem disappears.

A problem of known prior-art arrangements is,

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