Abstract: A method of dosing a nanocellulose suspension in gel phase into a second suspension, wherein the method comprises the steps of: providing said nanocellulose suspension in gel phase; providing said second suspension; bringing said nanocellulose suspension in gel phase in contact with said second suspension; wherein the method comprises a step of subjecting said nanocellulose suspension in gel phase to a shear rate of more than 500 l/s, simultaneously with and/or immediately prior to the step of bringing said nanocellulose suspension in gel phase and said second suspension in contact with each other.

Abstract: A method of and an arrangement for adding at least one additional stock component to an approach flow system (30) of a fiber web machine by mixing the at least one additional stock component to a fibrous stock such that the stock flow is equalized (50) and the at least one additional stock component is introduced to the stock flow by injection mixing (80).

Abstract: A method of and an arrangement for adding a chemical to an approach flow system of a fiber web machine by mixing of a retention chemical to a fibrous stock flowing in an approach flow system of a fiber web machine by a mixer (200) between the attenuator (16) and the headbox (18).

Abstract: A method to form a fibrous web including: introducing a furnish to a headbox of a fiber web machine, wherein the furnish includes a thick stock component and a filtrate, injecting a gas into to the furnish to form a foamed furnish, and laying the foamed furnish on a wire or between wires of a wire section of the fiber web machine to form the fibrous web from the foamed furnish.

Abstract: The present invention relates to a method of producing precipitated calcium carbonate (PCC) where a retention/strength enhancing chemical is added to milk of lime to form a mixture thereof prior to adding the mixture of the retention/strength enhancing chemical and milk of lime to paper making stock in a pipeline leading to a headbox of a paper making machine, whereafter carbon dioxide is introduced to the paper making stock, and the carbonation reaction between milk of lime and carbon dioxide is allowed to proceed in the presence of both fibers and the retention/strength enhancing chemical.

Abstract: An arrangement for mixing a fluid to a process liquid by using at least one mixing station and a method of operating the arrangement to feed injection or mixing liquid to injection mixers arranged on a periphery of a flow pipe transferring a process liquid. The arrangement and the method are applicable for the injection of mixers and chemical mixing in processes for the wood processing industry.

Abstract: A method to feed a chemical into a liquid flow using a feed device including a nozzle casing having an isolated mixing space including: feeding the chemical to the isolated mixing space in the feed device; feeding a mixing liquid to the isolated mixing space; mixing the chemical and the mixing liquid in the isolated mixing space to form a mixture of chemical and mixing liquid, and feeding the mixture of chemical and mixing liquid to the liquid flow.

Abstract: A method of manufacturing a fibrous web including: preparing furnish of a thick stock component and filtrate, preparing foamed furnish by mixing a surfactant and gas into the furnish, introducing the foamed furnish to a headbox of a fiber web machine, and laying the foamed furnish on a wire or between wires of a wire section of a fiber web machine for forming the fibrous web, wherein the preparation of the foamed furnish by injecting the gas uses an injection liquid to the furnish.

Abstract: A method of introducing a first flow and a second flow into a process liquid flowing through a conduit including: injecting the first flow with an introduction liquid into the process liquid in transverse to a flow direction of the process liquid, wherein the injected first flow forms a mixing field comprising counter-rotating vortices in the process liquid; and injecting a second flow transverse to the flow direction of the process liquid and between the counter-rotating vortices.

Abstract: A method and apparatus for in-line production of milk of lime into an in-line production process of PCC arranged in connection with a fibrous web machine. In the solution, lime is slaked in a slaking apparatus at a temperature of at least 80 degrees. The produced milk of lime is cleaned by separating excessively large calcium hydroxide particles immediately prior to introducing the milk of lime into the production process of PCC. The milk of lime is introduced into the in-line production process of PCC located in the production line of the end or intermediate product of the fibrous web machine.

Abstract: A method for mixing a chemical into a process liquid including: injecting the chemical into the process liquid flowing through a flow pipe; forming reaction products by a reaction involving the chemical occurring in the process flow; applying an electric field or magnetic field to a region of the flow pipe adjacent to the reaction occurring in the process flow, and suppressing the precipitation of the chemical or the reaction products on the surfaces of the pipe due to the electric or magnetic field.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

Abstract: Methods are provided 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.

Abstract: A feeding device for feeding a chemical into a process liquid flowing through a process liquid flow duct, the feeding device includes: a feeding liquid duct having a discharge opening; a mixing liquid feed duct extending through the feeding liquid duct, a sidewall and a closed end wall, wherein the end wall extends beyond the discharge opening of the feeding liquid duct and extending into the process liquid flow duct; a mixing space adjacent the end wall and within the sidewall of the mixing liquid feed duct; a chemical feed duct extending through the mixing liquid feed duct and having a discharge opening proximate to the mixing space in the mixing liquid feed duct, and a mixture discharge opening in the side wall of the mixing liquid feed duct.

Abstract: Methods are provided 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.

Abstract: 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.

Abstract: A method for production of calcium carbonate in a target suspension of a fibrous web forming process of a fibrous web machine, wherein the calcium carbonate is produced in a reactor, the method includes: injecting a chemical including carbon dioxide or lime milk through an injection mixer to the target suspension flowing through the reactor; allowing the chemical including to react while in the target suspension to form calcium carbonate crystals, and inhibiting precipitation of the chemical or a reaction product of the chemical on a surface of or in the reactor by application of an electric or magnetic field to or proximate to the surface along a region of the surface adjacent to the reaction involving the chemical.

Abstract: A method of introducing a first flow and a second flow into a process liquid flowing through a conduit including: injecting the first flow with an introduction liquid into the process liquid in transverse to a flow direction of the process liquid, wherein the injected first flow forms a mixing field comprising counter-rotating vortices in the process liquid; and injecting a second flow transverse to the flow direction of the process liquid and between the counter-rotating vortices.

Abstract: A method for mixing a chemical into a process liquid including: injecting the chemical into the process liquid flowing through a flow pipe; forming reaction products by a reaction involving the chemical occurring in the process flow; applying an electric field or magnetic field to a region of the flow pipe adjacent to the reaction occurring in the process flow, and suppressing the precipitation of the chemical or the reaction products on the surfaces of the pipe due to the electric or magnetic field.

Abstract: A method of feeding chemical to a liquid in an open space or flowing in an open space so that the chemical is fed to the liquid by means of a special mixing device or several special mixing devices by means of feed liquid introduced to the mixing device separately from the chemical by allowing the chemical and the feed liquid to discharge essentially simultaneously through the nozzle opening of the mixing device, the opening being located under the liquid level in the space, to the liquid in the space or flowing in the space.