Continuous methods of making fiber reinforced concrete panels

Patent metadata

Field	Value
Publication number	US-11224990-B2
Application number	US-201715663007-A
Country	US
Kind code	B2
Filing date	Jul 28, 2017
Priority date	Aug 5, 2016
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

Continuous method including mixing water and cementitous powder to form slurry; mixing the slurry and reinforcement fibers in a single pass horizontal continuous mixer to form fiber-slurry mixture, the mixer including an elongated mixing chamber having a reinforcement fiber inlet port, and upstream of the fiber inlet port is an inlet port to introduce water and cementitous powder together as one stream or at least two inlet ports to introduce water and dry cementitous powder separately as separate streams into the chamber, a rotating horizontal shaft/s within the chamber, part of the chamber for mixing the fibers and slurry and moving the fiber-slurry mixture to a mixture outlet; discharging the fiber-slurry mixture from the mixer outlet; forming and setting the fiber-slurry mixture on a moving surface; cutting the set mixture into fiber reinforced concrete panels and removing the panels from the moving surface.

First claim

What is claimed is:

1. A continuous method for preparing a fiber reinforced concrete panel comprising:
mixing water and dry cementitous powder to form a cementitous slurry, wherein the dry cementitious powder comprises at least one of Portland cement, calcium aluminate cements (CAC), calcium sulfoaluminate cements (CSA), geopolymers, magnesium oxychloride cements (sorel cements), and magnesium phosphate cements;
mixing the cementitous slurry and reinforcement fibers in a single pass horizontal continuous mixer to form a fiber-slurry mixture of fiber reinforced cementitous slurry mixture,
the single pass horizontal continuous mixer comprising:
an elongated mixing chamber defined by a horizontal housing having an interior cylindrical side wall,
at least one reinforcement fiber inlet port to introduce the reinforcement fibers through the interior cylindrical side wall directly into the mixing chamber, said reinforcement fibers comprises at least one of fiberglass, polymeric materials, polypropylene, polyethylene, polyvinyl alcohol, carbon, graphite, aramid, ceramic, steel or a combination thereof, and
upstream of the at least one fiber inlet port is (a) at least one inlet port to introduce the water and the dry cementitous powder together as one stream through the interior cylindrical side wall directly into the mixing chamber or (b) at least two inlet ports to introduce the water and the dry cementitous powder separately as separate streams through the interior cylindrical side wall directly into the chamber,
a fiber-slurry mixture outlet port at a downstream discharge end section of the horizontal housing to discharge the fiber reinforced cementitous slurry mixture, produced by the horizontal continuous mixer, laterally relative to the horizontal housing through an opening in the side wall of the horizontal housing into and through the fiber-slurry mixture outlet port on the horizontal housing,
a venting port to remove any air introduced into the mixing chamber from raw material feed, and
a rotating centrally horizontally oriented shaft mounted within the elongated mixing chamber traversing from one end of the horizontal continuous mixer to another end of the horizontal continuous mixer,
wherein the cementitous slurry and reinforcement fibers are mixed in a part of the mixing chamber for mixing the reinforcement fibers and cementitous slurry and moving the cementitous slurry and reinforcement fibers being mixed to the fiber-slurry mixture outlet;
wherein the centrally horizontally oriented shaft in the part of the mixing chamber for mixing the reinforcement fibers and cementitous slurry and moving the cementitous slurry and reinforcement fibers being mixed to the fiber-slurry mixture outlet comprises at least one mixing element selected from the group consisting of (1) an auger and (2) a plurality of mixing paddles mounted on the centrally horizontally oriented shaft at regular intervals and different circumferential locations to extend from the centrally horizontally oriented shaft, wherein the at least one mixing element rotates with the centrally horizontally oriented shaft within the housing;
wherein the cementitous slurry and reinforcement fibers are mixed in the mixing chamber of the horizontal fiber-slurry mixer for an average mixing residence time of about 5 to about 240 seconds while the at least one mixing element applies shear force, wherein the centrally horizontally oriented shaft rotates at 30 to 450 RPM;
discharging the fiber-slurry mixture laterally from the horizontal mixer through the opening in the side wall of the horizontal housing into and through the fiber-slurry mixture outlet port;
wherein, simultaneous with the discharging of the water, the dry cementitous powder, and the reinforcement fibers forming the fiber-slurry mixture from the single pass horizontal continuous mixer, further water, cementitous powder which is dry or combined with the further water, and reinforcement fibers forming further fiber-slurry mixture are fed to the single pass horizontal continuous mixer;
feeding the discharged fiber-slurry mixture to a forming assembly which deposits the fiber-slurry mixture on a moving surface of a panel production line uniformly as a layer 0.25 to 2 inches thick;
leveling the fiber-slurry mixture on the moving surface;
allowing the fiber-slurry mixture to set on the moving surface;
cutting the set fiber-slurry mixture into panels and removing the panels from the moving surface, wherein an additional layer of fiber-slurry mixture is not deposited on the deposited layer of fiber-slurry mixture.

2. The method of claim 1 , wherein the at least one mixing element is the plurality of mixing paddles.

3. The method of claim 1 , wherein the water and the dry cementitous material are mixed in a first mixer having a first mixing vessel which forms the cementitous slurry, the cementitious slurry discharges from the first mixer and feeds the single pass horizontal continuous mixer, and then the cementitous slurry and the fibers are mixed in a second fiber-slurry mixer comprising the single pass horizontal continuous mixer to form the fiber-slurry mixture,
wherein the first mixer is separate from the single pass horizontal continuous mixer.

4. The method of claim 3 ,
wherein the first mixer is a continuous slurry mixer,
wherein a liquid stream comprising the water is fed into the continuous slurry mixer through a liquid stream inlet and a stream of the cementitious material as a dry cementitous powder is fed into the continuous slurry mixer to form the cementitous slurry, said continuous slurry mixer having a horizontally or vertically mounted impeller;
wherein the cementitous slurry passes from the continuous slurry mixer into the horizontal continuous mixer comprising the single pass horizontal fiber-slurry continuous mixer and a stream of reinforcement fibers passes into the horizontal fiber-slurry continuous mixer and mixing the cementitous slurry and the reinforcement fibers to form the fiber-slurry mixture,
wherein the single pass horizontal fiber-slurry continuous mixer comprises
the plurality of mixing and conveying paddles mounted on the centrally horizontally oriented shaft, the paddles extending radially from a location on the centrally horizontally oriented shaft, the paddles comprising a pin engaged to a paddle head, the pin pivotally engaged to the centrally horizontally oriented shaft and/or the paddle head to permit pivotal rotation of the paddle head relative to the respective location on the centrally horizontally oriented shaft, wherein the plurality of paddles are arranged to mix the reinforcement fibers and cementitous slurry and move the cementitous slurry and reinforcement fibers being mixed to the fiber-slurry mixture outlet;
wherein the centrally horizontally oriented shaft is externally connected to a drive mechanism and a drive motor to accomplish said shaft rotation.

5. The method of claim 4 , wherein orientation of the paddle head having a broad surface with respect to the centrally horizontally oriented shaft vertical cross-section is from about 10° to 80°, wherein the overall dimensions of the paddles are such that the clearance space between the inner circumference of the mixing chamber and the paddle's furthermost point from the centrally horizontally oriented shaft is less than ¼.

6. The method of claim 1 , wherein the single pass horizontal continuous mixer is a single combination continuous mixer vessel performing the mixing of the water and cementitous material and reinforcement fibers, wherein a first section of the combination continuous mixer vessel produces the cementitous slurry by combining all dry powders, chemical additives, and water; and a second section of the combination continuous mixer vessel comprises the mixing cha

Assignees

• United States Gypsum Co

Inventors

• Dubey Ashish
• Groza Peter B
• Nelson Christopher R

Classifications

• B01F23/53 Primary

  using driven stirrers · CPC title

• B01F27/73

  with rotary discs · CPC title

• B28B1/526 Primary

  by delivering the materials on a conveyor of the endless-belt type · CPC title

• B01F27/2123

  Shafts with both stirring means and feeding or discharging means · CPC title

• B01F35/715

  Feeding the components in several steps, e.g. successive steps · CPC title