Method and system for slurry preparation and distribution

A method of delivering a slurry of predetermined density to a utilization outlet, said method comprising the steps of:

• (a) preparing a concentrated slurry of predetermined substantially uniform density in a vessel from a predetermined quantity of water and particulate material;
• (b) withdrawing the concentrated slurry from the vessel;
• (c) adding a desired amount of water to the concentrated slurry withdrawn from the vessel to produce a diluted slurry of predetermined density;
• and
• (d) permitting the diluted slurry to flow to the utilization outlet.

A slurry preparation and distribution apparatus comprising:

• a vessel for containing water and particulate material forming the slurry ingredients, said vessel having an interior defined by a bottom, side walls and a top;
• slurry mixing means mounted to said top of said vessel, said slurry mixing means including a motor, a gear drive mechanism coupled to said motor, and a mixing shaft coupled to said gear drive mechanism, said motor and said gear drive mechanism being located substantially outside said interior of said vessel so as not to contact any slurry contained within said vessel, said mixing shaft being oriented generally along an axis substantially normal to said bottom of said vessel and centrally of said interior of said vessel, said slurry mixing means further including an impeller secured to said mixing shaft at a first location and a propeller secured to said mixing shaft at a second location below said first location and closer to said bottom of said tank than said impeller so that rotation of said impeller and propeller causes the slurry ingredients to flow downwardly in the central interior region of said vessel, outwardly generally along the bottom thereof to said side walls, upwardly of said side walls towards said top of said vessel and inwardly towards said central interior region;
• a slurry outlet arranged in one of said side walls of said vessel;
• a mixing chamber having a first inlet coupled to said slurry outlet for receiving slurry of a first concentration from said vessel interior, a second inlet and an outlet;
• means coupled to said second inlet for supplying water to said mixing chamber to dilute the slurry to a second concentration;
• and
• a pump having an inlet coupled to said mixing chamber outlet for receiving the slurry diluted to said second concentration and an outlet for supplying said diluted slurry to a follow-on utilization apparatus.

A method of preparing a substantially uniform slurry mixture for distribution to a utilization site, said method comprising the steps of:

• (a) filling a vessel with a desired amount of water;
• (b) placing a desired amount of particulate material in the vessel;
• (c) mixing the particulate material and water by (i) drawing the ingredients downwardly in the central region of the vessel, (ii) pushing the ingredients outwardly from the central region along the bottom of the vessel to the inner periphery thereof, and (iii) permitting the ingredients to flow upwardly along the inner periphery of the vessel and inwardly to the central region;
• (d) continuing the mixing step (c) until the substantially uniform slurry is obtained and during subsequent distribution;
• (e) withdrawing the slurry from the vessel;
• (f) adding a desired amount of water to the slurry withdrawn from the vessel to produce a diluted slurry of preselected density;
• and
• (g) providing the diluted slurry to the utilization site.