Upm-kymmene Oyj Corporation

Wetend Technologies Oy

Fp-pigments Oy

Upm-kymmene Corporation

Matti Sipilä

Jouni Matula

Esko Kukkamäki

Mikko Maijala

Roope Maijala

Björn Lax

Päivi Solismaa

A method and apparatus for pretreating fibre material to be used in manufacturing paper or the like, for example, by precipitating mineral substances to the fibres. During precipitation, fibre material, which is advantageously pretreated in a through-flow mixer operating on the principle of an impact mill, is fed to the precipitation reactor. Gas is led to the precipitation reactor in order to generate a gas space in the reactor. The gas contains a substance, which precipitates the mineral substance such as carbon dioxide (CO). The fibre material is fed to the gas space of to the precipitation reactor as small liquid and solid substance fractions such as drops and/or particles.

Method and apparatus for pre-treatment of fibre material to be used in the manufacture of paper, board or the like

The method of the present invention for crystallizing a filler, especially in order to precipitate calcium carbonate on the surfaces of solids in the short circulation of a fiber web machine by feeding carbon dioxide and lime milk to the liquid flow of the short circulation and allowing them to react with one another, is characterized in that the feed system, the mixing method and/or mixing rate of the chemicals are selected such that a size distribution of the calcium carbonate crystals suitable for the purpose is obtained. Moreover, the invention relates to an approach system for a fiber web machine applying this method, characterized in that it is provided with devices for feeding and mixing carbon dioxide and lime milk into the liquid flow at such a rate that the applicable size distribution of the calcium carbonate crystals is obtained.

Method for crystallizing a filler in connection with a fiber web process, and an approach system for a fiber web machine

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Kuusankoski, Finland

Matti Sipilä