MEANS IN VAT SECTION OF CIRCULAR NET PAPERMAKING MACHINE

摘要

A cylinder-vat unit (1) having a cylinder mould (2), a vat (4) and a headbox (12) for supply of stock to the vat (4), which has a special wall means and is arranged upstream of the cylinder mould (2) in such a manner that a downwardly moving part of the liquid-­pervious outer surface of the cylinder mould (2) is brought into contact with stock (5) in the vat (4) to form a web by draining water from the stock (5) through said outer surface, an outer wire (18) running in a loop over a breast roll (19), through the vat (4) at the wall means thereof and then around a portion of the circumference of the cylinder moudl (2). According to the invention said wall means comprises an endless liquid-impervious belt (8) arranged to run in a loop located on the inner side of the loop defined by the outer wire (18), the belt (8) and the outer wire (18) running together in close surface contact with each other at least within the area situated between the breast roll (19) and the cylidner mould (2) so that the liquid-impervious belt (8) forms a liquid barrier for the stock in the vat.