A mixer has a circular housing defining a mixing area for mixing and kneading of a gypsum slurry. A rotary disc is positioned in the housing and rotated in a predetermined rotational direction. A rotary driving shaft cointegrally connected with the rotary disc and a plurality of scrapers are positioned in the mixing area. A slurry discharge port is provided on an annular wall of the housing for feeding the gypsum slurry of the mixing area onto a sheet of paper for gypsum board liner. An opening of the slurry discharge port is divided into a plurality of narrow openings, so that fluid resistance on the gypsum slurry flowing out of the mixing area is increased. An annular basal part rotates integrally with the rotary disc and an inner end portion of the scraper is fixed to the annular basal part.

A mixing apparatus for producing aqueous calcined gypsum slurry includes a housing, a rotor assembly, and an actuator system. The housing defines a mixing chamber therewithin. A top lid of the housing includes a lid ring extending along a normal axis toward a bottom thereof. The rotor assembly includes a rotor disposed within the mixing chamber and a drive shaft extending along and rotatable about the normal axis. The rotor is rotatively coupled with the drive shaft and extends radially therefrom. The upper surface of the rotor and the lid ring are separated by a lid ring gap along the normal axis. The actuator system is arranged with the rotor assembly to selectively move the rotor over a range of travel along the normal axis between a lowered position and a raised position to selectively change the lid ring gap.

A mixer has a circular housing defining a mixing area for mixing and kneading of a gypsum slurry. A rotary disc is positioned in the housing and rotated in a predetermined rotational direction. A rotary driving shaft cointegrally connected with the rotary disc and a plurality of scrapers are positioned in the mixing area. A slurry discharge port is provided on an annular wall of the housing for feeding the gypsum slurry of the mixing area onto a sheet of paper for gypsum board liner. An opening of the slurry discharge port is divided into a plurality of narrow openings, so that fluid resistance on the gypsum slurry flowing out of the mixing area is increased. An annular basal part rotates integrally with the rotary disc and an inner end portion of the scraper is fixed to the annular basal part.

A discharge gate is provided for a gypsum slurry mixer, and includes a lower member having an inlet opening configured for receiving the slurry, and an outlet opening configured for delivering the slurry to a dispensing device. An upper member is attached to the lower member, at least one of the upper and lower members having at least one opening for accommodating insertion of an injection port for introducing the foam to the slurry. A cavity is configured for mixing the foam and slurry, and is defined by inner surfaces of the lower member and the upper member.

A multi-leg discharge boot can include an inlet conduit and first and second outlet conduits separated by a junction portion. The inlet conduit includes an entry segment, a transition segment and a heel portion disposed therebetween. The inlet conduit can include an inlet end and a junction end. A junction portion is disposed at the junction end of the inlet conduit between first and second junction openings. The junction portion includes a substantially planar wall region that is substantially perpendicular to a main flow discharge axis.

Turning motion of gypsum slurry spouting onto a sheet of paper for a gypsum board liner is restricted for preventing maldistribution, deviation or irregular dispersion from occurring in the density distribution of the slurry on the sheet of paper. A mixing and stirring device for gypsum slurry has a circular casing forming a mixing area, a rotary disc positioned in the casing, and a tubular passage for feeding the slurry onto the sheet of paper for the gypsum board liner. A chute has a fluid passage portion with its cross section being non-axisymmetric with respect to a center axis of the tubular passage, or a fluid passage portion varying a position of the center axis of the tubular passage by a change or lateralization of the cross section of fluid passage.

A discharge gate is provided for delivering a mixed slurry from a gypsum slurry mixer, and includes a first extractor port configured for generating a first density slurry for a first gypsum layer, and a second extractor port configured for generating a second density slurry for a second gypsum layer. A channel is defined by a front panel and a side panel of the discharge gate for delivering the first and second density slurries from the slurry mixer. The first extractor port extends semi-tangentially from the front panel of the discharge gate, and is connected in fluid communication with the front panel via the channel and a first slurry passageway disposed within the first extractor port for delivering the first density slurry.

A discharge gate for a gypsum slurry mixer is provided, and includes a gate adapter having an inlet opening configured for receiving the slurry, and an outlet opening configured for delivering the slurry to a dispensing device. The gate adapter has two different transitioning cross-sectional geometries at opposite ends. Specifically, the gate adapter includes an inlet section having a quadrilateral inlet opening; an outlet section having a substantially circular outlet opening; and a transition section sandwiched between the inlet and outlet sections.

A discharge gate is provided for delivering a mixed slurry from a gypsum slurry mixer, and includes a first extractor port configured for generating a first density slurry for a first gypsum layer, and a second extractor port configured for generating a second density slurry for a second gypsum layer. A channel is defined by a front panel and a side panel of the discharge gate for delivering the first and second density slurries from the slurry mixer. The first extractor port extends semi-tangentially from the front panel of the discharge gate, and is connected in fluid communication with the front panel via the channel and a first slurry passageway disposed within the first extractor port for delivering the first density slurry.

[Object] Behavior of a flow of foam or foaming agent ejected to a gypsum slurry can be stabilized, and a relatively large amount of foam or foaming agent can be homogeneously or uniformly dispersed in the slurry.

[Solution] A mixer (10) has a mixing area (10a) for preparing gypsum slurry (3), a slurry delivery section (4) for delivering the slurry from the mixing area, and a feeding port (60) for feeding foam (M) or a foaming agent to the slurry in the mixing area and/or the slurry delivery section under pressure. The slurry having the foam mixed therein is supplied to a production line (1) for forming gypsum boards or gypsum-based boards. The feeding port is provided with a partition member (62,64,65) dividing an ejecting region (61,61). The ejecting region is divided into a plurality of openings (63), which simultaneously eject the foam or forming agent to the slurry.