Systems and methods for making gypsum board using a liquid gypsum set accelerator. Stucco and water are mixed to form a gypsum slurry, such as in a pin mixer. A gypsum set accelerator is mixed with a liquid medium to form a liquid gypsum set accelerator, such as in an eductor. The liquid gypsum set accelerator is added to the gypsum slurry, which is shaped to form the gypsum board.

The present invention relates to a method and an arrangement for dissolving starch. Specifically, the present invention relates to a method for dissolving starch by introducing mechanical force to at least partially gelatinized agueous starch.

A vane for an impeller of an agitator includes a socket having a base plane configured to mount the vane to an impeller, and a blade configured to mix a process fluid, the blade having a leading edge, a trailing edge, and a blade tip extending from the leading edge to the trailing edge at an end of the blade facing away from the socket, the blade having a pressure side and a suction side, and the pressure side having a first concave region towards the leading edge, a second concave region toward the trailing edge and a convex region between the first and second concave regions.

A process for producing paper or board, which process comprises ad-mixing (I) an aqueous composition of pH ≦6 and (II) at least one water-soluble polymeric anionic compound to a paper stock having a pH in the range from 6 to 8 and then dewatering the paper stock by sheet formation and drying, wherein the aqueous composition comprises (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ≧1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and/or amidine groups of the polymers, and also to the paper or board thus obtained.

A stirring apparatus includes a shredder that shreds a sheet; a case that accommodates a sheet piece shredded by the shredder and has a bottom surface and an inner surface; and a rotator that is disposed at the bottom surface of the case and includes a blade which stirs the sheet piece by rotation, in which L1<L3<L2, when between an outer end of the blade and the inner surface in a radial direction of the rotator, a shortest distance in the radial direction is defined as L1, a longest distance in the radial direction is defined as L2, and an average major axis length of the sheet piece is defined as L3.

A vane for an impeller of an agitator for mixing or agitating a process fluid includes a socket for mounting the vane to an impeller and a blade for mixing or agitating the process fluid, the blade being connected to the socket, the blade having a leading edge, a trailing edge, and a blade tip extending from the leading edge to the trailing edge at the end of the blade facing away from the socket, and the blade having a height and a width. The height is the maximum distance of the blade tip from the socket and the width is the distance of the leading edge from the trailing edge. The blade has a maximum width that is at least 55 percent.

A stirring apparatus includes a case that houses fiber pieces containing fibers, and a rotary body that is disposed inside the case and that stirs the fiber pieces, in which the rotary body includes a rotary portion that forms a portion of a bottom surface of the case and that rotates, and blades that stand upright on the rotary portion.

A vane for an impeller of an agitator includes a socket having a base plane configured to mount the vane to an impeller, and a blade configured to mix a process fluid, the blade having a leading edge, a trailing edge, and a blade tip extending from the leading edge to the trailing edge at an end of the blade facing away from the socket, the blade having a pressure side and a suction side, and the pressure side having a first concave region towards the leading edge, a second concave region toward the trailing edge and a convex region between the first and second concave regions.

A method for determining a property of a fiber suspension comprises obtaining a sample and diluting the sample by a first dilution, thereby providing a diluted sample, while retaining essentially all of the sample, and mixing the diluted sample, thereby providing a mixed, diluted sample. By removing part of the mixed, diluted sample and retaining an amount of the mixed, diluted sample, further diluting the mixed, diluted sample by adding dilution water to the retained amount of the mixed, diluted sample, thereby providing a further diluted sample, while retaining essentially all of the mixed, diluted sample, mixing the further diluted sample, thereby providing a mixed, further diluted sample, and repeating these steps until the concentration is suitable for measuring the property of the further diluted sample, this property can be measured with high accuracy. A device for determining a property to be determined of a suspension is also provided.

A stirring apparatus includes a case that houses fiber pieces containing fibers, and a rotary body that is disposed inside the case and that stirs the fiber pieces, in which the rotary body includes a rotary portion that forms a portion of a bottom surface of the case and that rotates, and blades that stand upright on the rotary portion.