US-12617123-B2 - Slurry roller conveyor for gypsum board manufacture

US12617123B2US 12617123 B2US12617123 B2US 12617123B2US-12617123-B2

Abstract

A slurry distributing device including a roller conveyer having a series of roller sections, each section driven by a respective motor and employing a combination of direct drive and belt drive. The slurry distributing device is used for the uniform and low-speed flow distribution of slurries. The invention also relates to a conveyor line for the continuous production of gypsum drywall boards employing the slurry distributing device. The invention also relates to a method for the continuous production of gypsum drywall boards employing the slurry distributing device.

Inventors

Nicholas Stephen JONES
Leslie Leamon EVERSOLE
Ronald Edward Schenck

Assignees

KNAUF GIPS KG

Dates

Publication Date: 20260505
Application Date: 20240705

Claims (6)

1 . A slurry distributing device comprising: a roller conveyer comprising: a support frame; parallel rollers, disposed in parallel with one another in a common and rotatably mounted about their longitudinal axes in the support frame and disposed essentially perpendicular to a delivery direction of the slurry; wherein the slurry distributing device is adapted and configured to be supplied with the slurry from at least one mixing device, and to adapt a speed of the slurry to a conveying device speed and to distribute the slurry uniformly over a desired width of an upper surface of the rollers, the parallel rollers are provided in a series of at least two adjacent said parallel rollers, wherein each roller section has a respective variable speed drive for driving the rollers of the respective roller section all in the same direction and controlling rotation speed of the rollers of the respective roller section to control spread of the slurry, as the slurry moves over the upper surface of the parallel rollers, to distribute and level the slurry, wherein each roller section comprises: a first plurality of pulleys aligned along a first axis and a second plurality of pulleys aligned along a second axis, said first axis is parallel to the said second axis and parallel to a machine direction of the slurry distributing device which is perpendicular to the rollers of the roller section, the first plurality of pulleys and the second plurality of pulleys adapted and configured to rotate while the rollers rotate, a direct drive roller connected by direct drive to its respective variable speed drive for driving the direct drive roller, and a first belt roller connected to its respective direct drive roller by a first belt drive for driving the first belt roller, wherein said first plurality of pulleys comprises a direct drive roller pulley concentrically connected to the direct drive roller and a first belt roller pulley concentrically connected to the first belt roller, a second belt roller connected to its respective first belt roller by: a) a second belt drive for driving the second belt roller, the second belt drive comprising a second belt, or b) the first belt drive, wherein if the second belt roller is connected to the first belt roller by the first belt drive then the first belt is adapted and configured to travel along a U-shaped path from the first belt roller pulley concentrically connected to the first belt roller, then onto an intermediate free spinning pulley, and then to a second belt roller pulley concentrically connected to the second belt roller, wherein the first belt roller pulley and second belt roller pulley are pulleys of the first plurality of pulleys and aligned along the first axis, the intermediate free spinning pulley is a pulley of the second plurality of pulleys and aligned along the second axis, and the first axis and second axis are in a plane perpendicular to a longitudinal axis of the first belt roller and a longitudinal axis of the second belt roller wherein the first belt drive comprises: the direct drive roller pulley, the first belt roller pulley, and a first belt contacting the direct drive roller pulley and the first belt roller pulley; and the slurry distributing device is adapted and configured to then deliver the distributed slurry onto a lower layer, wherein the slurry distributing device actively transports the slurry.
2 . The slurry distributing device according to claim 1 , wherein the second belt roller is connected to its respective first belt roller by the second belt drive.
3 . The slurry distributing device according to claim 2 , wherein the first belt drive comprises: the direct drive roller pulley concentrically connected to the direct drive roller, the first belt roller pulley, wherein the first belt roller pulley is a primary pulley of the first belt roller, and the first belt, wherein the first belt is adapted and configured to travel on the direct drive roller pulley and the primary pulley of the first belt roller to rotate the first belt roller; and wherein the second belt drive comprises: a first belt roller secondary pulley concentrically connected to the first belt roller, wherein the first belt roller secondary pulley is a pulley of the second plurality of pulleys, and a second belt roller secondary pulley concentrically connected to the second belt roller, and the second belt, wherein the second belt travels on the first belt roller secondary pulley and the second belt roller secondary pulley to rotate the second belt roller; wherein the primary pulleys are aligned along the first axis, the secondary pulleys are aligned along the second axis, and the first axis and second axis, the longitudinal axis of the first belt roller and the longitudinal axis of the second belt roller are aligned in a plane.
4 . The slurry distributing device according to claim 1 , wherein the second belt roller is connected to its respective first belt roller by the first belt drive, wherein the first belt travels along the U-shaped path from the first belt roller pulley connected to the first belt roller, then onto the intermediate free spinning pulley, and then to a second belt roller pulley concentrically connected to the second belt roller.
5 . A slurry distributing device comprising: a roller conveyer comprising: a support frame; parallel rollers, disposed in parallel with one another in a common and rotatably mounted about their longitudinal axes in the support frame and disposed essentially perpendicular to a delivery direction of the slurry; wherein the slurry distributing device is adapted and configured to be supplied with the slurry from at least one mixing device, and to adapt a speed of the slurry to a conveying device speed and to distribute the slurry uniformly over a desired width of an upper surface of the rollers, the parallel rollers are provided in a series of at least two adjacent said parallel rollers, wherein each roller section has a respective variable speed drive for driving the rollers of the respective roller section all in the same direction and controlling rotation speed of the rollers of the respective roller section to control spread of the slurry, as the slurry moves over the upper surface of the parallel rollers, to distribute and level the slurry, wherein each roller section comprises: a first plurality of pulleys aligned along a first axis and a second plurality of pulleys aligned along a second axis, said first axis is parallel to the said second axis and parallel to a machine direction of the slurry distributing device which is perpendicular to the rollers of the roller section, the first plurality of pulleys and the second plurality of pulleys adapted and configured to rotate while the rollers rotate, a direct drive roller connected by direct drive to its respective variable speed drive for driving the direct drive roller, and a first belt roller connected to its respective direct drive roller by a first belt drive for driving the first belt roller, wherein said first plurality of pulleys comprises a direct drive roller pulley concentrically connected to the direct drive roller and a first belt roller pulley concentrically connected to the first belt roller, wherein the first belt drive comprises: the direct drive roller pulley, the first belt roller pulley, and a first belt contacting the direct drive roller pulley and the first belt roller pulley; wherein the parallel rollers of each roller section are supported by opposed mounting roller bearings, each said mounting roller bearing has a two part construction including an upper part removably attached to a lower part so the upper part can be lifted off the lower part to access the rollers of the roller section and the slurry distributing device is adapted and configured to then deliver the distributed slurry onto a lower layer, wherein the slurry distributing device actively transports the slurry.
6 . A method for the use of a slurry distributing device comprising a roller conveyer, a support frame; parallel rollers, disposed in parallel with one another in a common and rotatably mounted about their longitudinal axes in the support frame and disposed essentially perpendicular to a delivery direction of the slurry; wherein the slurry distributing device is adapted and configured to be supplied with the slurry from at least one mixing device, and to adapt a speed of the slurry to a conveying device speed and to distribute the slurry uniformly over a desired width of an upper surface of the rollers, the parallel rollers are provided in a series of at least two adjacent said parallel rollers, wherein each roller section has a respective variable speed drive for driving the rollers of the respective roller section all in the same direction and controlling rotation speed of the rollers of the respective roller section to control spread of the slurry, as the slurry moves over the upper surface of the parallel rollers, to distribute and level the slurry, wherein each roller section comprises: a first plurality of pulleys aligned along a first axis and a second plurality of pulleys aligned along a second axis, said first axis is parallel to the said second axis and parallel to a machine direction of the slurry distributing device which is perpendicular to the rollers of the roller section, the first plurality of pulleys and the second plurality of pulleys adapted and configured to rotate while the rollers rotate, a direct drive roller connected by direct drive to its respective variable speed drive for driving the direct drive roller, and a first belt roller connected to its respective direct drive roller by a first belt drive for driving the first belt roller, wherein said first plurality of pulleys comprises a direct drive roller pulley concentrically connected to the direct drive roller and a first belt roller pulley concentrically connected to the first belt roller, a second belt roller connected to its respective first belt roller by: a) a second belt drive for driving the second belt roller, the second belt drive comprising a second belt, or b) the first belt drive, wherein if the second belt roller is connected to the first belt roller by the first belt drive then the first belt is adapted and configured to travel along a U-shaped path from the first belt roller pulley concentrically connected to the first belt roller, then onto an intermediate free spinning pulley, and then to a second belt roller pulley concentrically connected to the second belt roller, wherein the first belt roller pulley and second belt roller pulley are pulleys of the first plurality of pulleys and aligned along the first axis, the intermediate free spinning pulley is a pulley of the second plurality of pulleys and aligned along the second axis, and the first axis and second axis are in a plane perpendicular to a longitudinal axis of the first belt roller and a longitudinal axis of the second belt roller; wherein the first belt drive comprises: the direct drive roller pulley, the first belt roller pulley, and a first belt contacting the direct drive roller pulley and the first belt roller pulley; and the slurry distributing device is adapted and configured to then deliver the distributed slurry onto a lower layer, wherein the slurry distributing device actively transports the slurry, including producing gypsum plasterboards in a continuous process.

Description

FIELD OF THE INVENTION This invention relates to a slurry distribution roller device for the production of drywall boards. In particular, the invention relates to a distributing device for the uniform distribution of suspensions or slurries and system for gypsum board manufacture using the slurry distribution roller device. The invention may also relate to the use of the slurry distributing device comprising the roller conveyor comprising parallel rotatable rollers in an apparatus and a method for gypsum board manufacture. BACKGROUND OF THE INVENTION Drywall boards, for example based on gypsum, are typically produced by continuous production processes. A slurry comprising the solid and the liquid components, essentially calcined gypsum, water and additives, is first produced in a mixer. The slurry is optionally foamed mechanically or chemically. The slurry is then deposited on a facer sheet or directly on a belt. Paper or nonwoven fabric are typically used as facer materials. If a multilayer drywall board is to be produced, a plurality of layers of identical or different slurries are deposited upon one another. Located in the middle of the board is the so-called core layer, which typically makes up 50 to 90 wt.-% of the total mass of the plasterboard. When a plurality of mixers is used, the core layer is fed from the main mixer. During the setting of the material, a forming station is usually passed through, said forming station ensuring that a clean edge formation takes place. The endless strip thus produced is then cut into pieces. The excess (hyperstoichiometric) water, which has not reacted with the calcined gypsum, is expelled in a drying station. If the drywall board has a multilayer structure, a plurality of layers of slurry have to be deposited upon one another in production. For this purpose, the slurry is often deposited on a lower layer by means of one or more hoses. When the slurry strikes the lower layer, it has a speed dependent on the cross-section of the delivery hose and on the delivery pressure. In order to achieve a good bond between the individual plies or layers, the next layer is deposited before the preceding layer has fully set or hardened. However, this has the drawback that the preceding layer is not yet stable at the time of deposition of the next layer. It can easily be damaged, i.e. so-called flushing effects can occur in the region of the deposition of the slurry. Initially uniformly deposited material of the layer lying beneath is flushed away or displaced in the region of the subsequently fed material and accumulates at other points of the board, in particular in its edge regions. The formation of layers is therefore non-uniform. The flushing effect may be more or less pronounced depending on the delivery pressure, the cross-section of the delivery hoses, the positioning of the discharge hoses and the impact angle of the slurry on the layer lying beneath. These flushing effects occur especially in the case of thin layers that are deposited directly on the casing material. Such layers are referred to as boundary layers. Since these layers often have special functions, for example a fire protection function or increased water resistance, weak points in these functions arise in the areas in which the material has been washed away. The quality of the end products is thus markedly reduced. Prior devices and methods for addressing some of the operational problems associated with the production of gypsum wallboard are disclosed in the following: U.S. Pat. Nos. 5,683,635; 5,643,510; 6,494,609; 6,874,930; 7,007,914; and 7,296,919; 9,999,989 to Rago et al.U.S. Pat. No. 10,076,853 to Wittbold et al.; U.S. Pat. No. 9,909,718 to Wittbold et al.U.S. Pat. No. 10,286,572 to Li et al.; U.S. Pat. No. 10,052,753 to Li et al.; U.S. Pat. No. 10,239,230 to Li et al.; U.S. Pat. No. 9,616,591 to Li et al.WO2015/185251-A1 to Martin et al and WO2015/185143-A1 (corresponding to EP 3152022 B1) to Martin et al. Various distributor devices are known that are intended to counteract the occurrence of these flushing effects and to promote a more uniform layer deposition. In principle, it is the aim of all methods to reduce the discharge pressure in the delivery hoses, especially of the main mixer. This can be achieved by reducing the flow rates in the discharge hoses, in that the hose diameter or the number of discharge hoses is increased. The core material is typically discharged from the main mixer with one hose and then distributed into boot with one discharge leg and can be increased up to three legs to help spread the slurry onto the paper or discharged from the main mixer with three up to a maximum of four hoses. The number of discharge hoses cannot be increased arbitrarily. It is limited by the geometry of the mixer. Both measures, the enlargement of the hose diameter and the increase in the number of discharge hoses, lead to an improvement in the flushing effect, but they do not remove it sufficientl