Abstract: The invention concerns multi-layer web formation by means of a simple basic-stock system and in particular a method for regulation of the properties of the different layers in a stock system that comprises several layers by means of additional stocks. The source (M) of basic stock is divided into 2 . . . n separate component flows (M1 . . . Mn), with which additional stocks (B1 . . . Bn) are mixed so as to form homogeneous mixtures with the basic stock, and the homogeneous stock flows are passed further by means of pumps (A1 . . . An) through machine screens (s1 . . . Sn) into the inlet header of a multi-layer headbox (P).

Abstract: An apparatus for degassing an aqueous suspension containing pulp fibres, the apparatus comprising an elongated horizontal reservoir and a bypass manifold extending into the reservoir. The bypass manifold is placed inside the reservoir such that it it positioned substantially within the aqueous suspension at the bottom of the reservoir, the manifold thus decreasing the flow cross-sectional area of the aqueous suspension at the inlet end of the bypass manifold (2) in the reservoir.

Abstract: A stock feed system for a multi-layer headbox and a method in the operation of a multi-layer headbox in which into each inlet header of the multi-layer headbox, a stock concept is passed which has been produced out of the same fresh stock by adding the necessary chemicals and fillers to separated portions of the fresh stock.

Abstract: A process arrangement for the short circulation in a paper or board machine including stock chests for component stocks, metering pumps for component stocks, cleaning devices, pumps, a headbox and a wire section as well as a system of pipes connecting these elements, together with regulation devices. After the metering pumps, the component stock flows are passed into a closed mixing volume in which the component stocks are mixed and diluted with a first dilution water flow. From this closed mixing volume, the stock is passed in a closed space by a first feed pump of the main line of the process through a screen and a centrifugal cleaner to the suction side of a second feed pump of the main line, where a second dilution water flow is passed to the stock. The second feed pump feeds the stock through a machine screen to the inlet header in the headbox.

Abstract: A method in a paper machine for arrangement of water circulation therefor and arrangement of a water circulation system in a paper machine. In view of full or partial closing of the water circulations in a paper machine, the wash water flows from the fabrics and from other devices in the paper machine as well as the water drained from the paper web to be produced are recovered selectively based on the place of origin thereof in the paper machine. At least a part of the recovered different water flows are cleaned, and the cleaned water flows are recirculated to applications of reuse suitable in view of their washing potential in the papermaking process.