Abstract: A method and apparatus for feeding a retention chemical together with an additive, which may be another chemical or for example a mineral, to paper suspension flow in a paper machine. The method and the apparatus are applicable to the simultaneous feeding of an additive of the paper manufacture, such as a filler, together with a retention chemical to paper pulp.

Abstract: The present invention relates to a method and apparatus for feeding chemical into a liquid flow by means of a feeding device including a nozzle casing and apparatus disposed in connection therewith, having means for feeding chemical and means for feeding mixing liquid to an isolated space disposed in connection with the nozzle casing. The method and apparatus according to the invention are especially suitable for applications where very small volumes of chemical must be fed in precise amounts in large process liquid flows.

Abstract: A method of and apparatus for feeding a chemical into a liquid flow are especially suited for use with a headbox of a paper machine, particularly for feeding a retention aid into a fiber suspension flow going to the headbox so that in a mixing apparatus feed liquid is added into the retention chemical solution, prior to introducing the solution into the fiber suspension flow guided to the paper machine. The feed liquid is preferably a circulation water from the paper mill, or another non-clean liquid from a paper mill.

Abstract: A method of feeding chemical to a liquid flowing in an open space, the method including: feeding the chemical to the liquid by at least one special mixing device; introducing a feed liquid to the at least one special mixing device separately from the chemical; contacting the chemical and the feed liquid together essentially simultaneously with the discharge of the chemical and the feed liquid through a nozzle opening of the mixing device, wherein the nozzle opening is located under a surface of the liquid flowing into the open space.

Abstract: A method of and apparatus for feeding a chemical into a liquid flow are especially suited for use with a headbox of a paper machine, particularly for feeding a retention aid into a fiber suspension flow going to the headbox so that in a mixing apparatus feed liquid is added into the retention chemical solution, prior to introducing the solution into the fiber suspension flow guided to the paper machine. The feed liquid is preferably a circulation water from the paper mill, or another non-clean liquid from a paper mill.

Abstract: The present invention relates to a method of and an apparatus for controlling the operation of the short circulation of a paper, paper board or the like production machine. The method and apparatus according to the invention are especially preferably suitable for use in the approach system, i.e. so-called short circulation, of said production machines for regulating the headbox feed pressure. A characteristic feature of the method and apparatus according to the invention is that at a suitable location in the approach system of said production machine there is arranged a controllable parallel flow, by means of which at least one flow in the approach system is regulated so that the pressure in the headbox remains essentially constant.

Abstract: The present invention relates to a method and apparatus for controlling the operation of an approach system of a paper machine or the like web formation apparatus. Especially preferably the method of controlling the operation of an approach system according to the invention is applicable to be used in connection with paper and paperboard machines as well as in connection with various apparatuses performing non-woven webformating.

Abstract: The present invention relates to a wire pit. A characteristic feature of the wire pit (50) according to the invention is that its wall/walls (52′, 52″, 54′, 62) converge downwards so that the average flow direction of the liquid along the most part of the wire pit's (50) height deviates from vertical.

Abstract: A method of and apparatus for feeding a chemical into a liquid flow are especially suited for use with a headbox of a paper machine, particularly for feeding a retention aid into a fiber suspension flow going to the headbox so that in a mixing apparatus feed liquid is added into the retention chemical solution, prior to introducing the solution into the fiber suspension flow guided to the paper machine. The feed liquid is preferably a circulation water from the paper mill, or another non-clean liquid from a paper mill.

Abstract: The present invention relates to a method of and an apparatus for controlling the operation of the short circulation of a paper, paper board or the like production machine. The method and apparatus according to the invention are especially preferably suitable for use in the approach system, i.e. so-called short circulation, of said production machines for regulating the headbox feed pressure. A characteristic feature of the method and apparatus according to the invention is that at a suitable location in the approach system of said production machine there is arranged a controllable parallel flow, by means of which at least one flow in the approach system is regulated so that the pressure in the headbox remains essentially constant.

Abstract: A method of and apparatus for feeding a chemical into a liquid flow are especially suited for use with a headbox of a paper machine, particularly for feeding a retention aid into a fiber suspension flow going to the headbox so that in a mixing apparatus feed liquid is added into the retention chemical solution, prior to introducing the solution into the fiber suspension flow guided to the paper machine. The feed liquid is preferably a circulation water from the paper mill, or another non-clean liquid from a paper mill.

Abstract: The present invention is related to a method of determining the amount of gas in a liquid. The method is particularly well suited for determining the amount of both the gas in the form of bubbles and the gas dissolved in pulp, i.e. in various fiber suspensions of paper and pulp industry. The invention is advantageously applied to the control and regulation applications of removal of air in the short circulation of a paper machine.

Abstract: A means for degassing paper pulp stock, comprising an elongated horizontal cylindrical tank, a distribution pipe parallel to the tank and wherefrom departs a plurality of consecutive jet tubes for introducing pulp stock into the tank close to one end of the tank, an exit tube located close to the opposite end of the tank and towards which the pulp stock flows on the bottom of the tank, members to maintain the pulp stock level constant in the tank, an additional exit tube for returning to circulation the excess pulp stock that has entered the tank, and members for producing a vacuum in the tank. The distribution pipe and the flow therewithin are directed in opposition to the flow within the tank. The cross section area of the flow diminishes towards that end of the tank where the jet tubes are located, the diminishing flow cross section area extending at least over the region of one jet tube.

Abstract: Hydrocyclone for dividing a substance mix into an acceptable fraction and a reject fraction containing dirt substances, the hydrocyclone including a separating chamber, which in part consists of a cylinder part, provided with at least one tangential feed connector for the substance mix and with a coaxial exit tube for the acceptable fraction, and which in part consists of a sorter cone on the extension of the cylinder part, having at its apex an exit aperture for the reject fraction.

Abstract: Disk defibrator presenting a feed device for supplying the material which one desires to defibrate, such as wood chips, into the throat of the disk defibrator with the aid of a screw conveyor, the steam generated during the defibration process escaping through the feed device in countercurrent to the material flow and further passing to the atmosphere through an exit aperture on the feed device. The feed device includes two feed screws side by side with an intervening space into which the steam freely discharges.

Abstract: For a disk refiner which includes a frame with a refiner housing, a driving shaft, and a driving motor, a mounting base in the form of an integrated block made of a material absorbent to vibrations of the disk refiner, said block having at one end, symmetrically in relation to the longitudinal central line of the base, support surfaces for the driving motor and, at its other end, two front supports for the refiner frame and, at a distance from said front supports, two rear supports for the refiner frame, said front and rear supports being situated pairwise symmetrically in relation to the shaft of the refiner, essentially in a plane extending along the longitudinal central line of the shaft, and at the ends of column-like projections extending upwards from a plane defined by said support surfaces.

Abstract: A disk refiner construction to be supported on a base and including first and second frame parts, said first frame part having inside a pressure proof housing attached at its periphery to said first frame part, a shaft extending into said housing and provided with a gasketing sleeve serving as a gasket for said housing, a disk attached to the end of said shaft and provided with refiner plates within the housing, and an end plate of the refiner being attached to the first frame part and provided with stationary counter plates for said refiner plates, the second frame part having inside a bearing unit for the shaft of the refiner and said first and second frame parts constituting together an uninterrupted frame having the shape of a hollow rotational body and serving as a guide and support for the shaft and its bearings, said body being further provided with fixation points positioned symmetrically in relation to the shaft for supporting the disk refiner on its base.