Method and reactor for producing produce calcium carbonate
AssigneeWetend Technologies Oy
InventorJouni MATULA
Life of this patent
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Abstract
A method and a reactor to crystalize calcium carbonate and to form crystals in a liquid flow (F) with the concentration of 2.5% to 5% inside or on the surfaces of a fiber dispersion containing solid matter. The method includes feeding carbon dioxide (CO2) and lime milk (LM) (Ca(OH)2) into the liquid flow and reacting the CO2 with the Ca(OH)2 wherein the carbon dioxide (CO2) and/or lime milk (LM) is injected with a mixer crosswise into the liquid flow (F) and the injection is performed with a feed tube (2) to cause a dwell time of the crystallizing reaction of 0.5 to 10 seconds before a nozzle (20) of the reactor (1), after which the liquid flow (F) is mixed with the liquid or fiber suspension in container (4)
Claims20
A method for crystallizing calcium carbonate and for formation of crystals in a liquid flow with a concentration in a range of 2.5% to 5% in a solid matter fiber suspension and/or surfaces of the solid matter fiber suspension, wherein the method includes:
- feeding carbon dioxide and lime milk into a liquid flow to cause a reaction between the carbon dioxide and lime milk, wherein the feeding includes injecting through at least one mixer the carbon dioxide and/or lime milk obliquely to a flow direction of the liquid flow in small particles or bubbles to cause the carbon dioxide and/or lime milk to disperse evenly in the liquid flow regardless of flow conditions of the liquid flow to create a suitable size distribution of homogenic calcium carbonate crystals, to prevent formation of oversized produced calcium carbonate crystals, produced calcium carbonate deposits and/or produced calcium carbonate precipitations and to control the reaction between the carbon dioxide and the lime milk,
- wherein the injecting is performed by injecting the carbon dioxide and lime milk in a feed tube such that the carbon dioxide and the lime milk flow with the liquid flow during a dwell time in a range of 0.5 to 10 seconds during which the carbon dioxide and lime milk undergo a crystallizing reaction to form crystallized calcium carbonate and wherein the liquid flow with crystallized calcium carbonate flow through a nozzle from the feed tube into a fiber suspension in a container.
A reactor configured to crystallize calcium carbonate to form crystals in a liquid flow with a concentration in a range of 2.5 to 5% in or on a surface of a fiber dispersion containing solid matter, wherein the reactor includes:
- a feed pipe through which passes the liquid flow;
- at least one mixer configured to inject carbon dioxide and lime milk obliquely into the liquid flow moving through the feed pipe, and
- a nozzle
- wherein the feed pipe has a length from the at least one mixer to the nozzle to provide a dwell time in a range of 0.5 to 10 seconds for the liquid flow moving through the feed pipe from the at least one mixer to the nozzle.
A method to crystallize calcium carbonate in a liquid flow passing through a feed pipe and into a container, the method comprising:
- passing the liquid flow through the feed pipe;
- injecting carbon dioxide and lime milk into the liquid flow passing through the feed pipe wherein the carbon dioxide and/or lime milk are injected obliquely into the liquid flow;
- after the injection, the liquid flow passing with the carbon dioxide and lime milk remain in the feed tube for a dwell period of 0.5 to 10 seconds during which the carbon dioxide and lime milk react to form the crystallized calcium carbonate;
- immediately after the dwell period the liquid flow with the crystallized calcium carbonate pass from the feed tube and through a nozzle attached to the feed tube;
- injecting by the nozzle the liquid flow with the crystallized calcium carbonate into a fiber suspension in the container.
Dependencies are inferred from the claim text.