US 4,363,786 A · Apparatus for reacting a particulate solid and a liquid

Abstract

An apparatus useful for the preparation of phosphoric acid from phosphate rock and a strong acid, comprises a closed vessel, a draft tube, means connected to the inner walls of said vessel amd mounting said draft tube in a vertical position within said vessel, an agitator positioned within said draft tube, a shaft for said agitator mounted axially of said vessel and extending into said draft tube, an inlet conduit to said vessel for introducing a feed slurry (e.g. phosphate rock and strong acid) into said vessel, said inlet conduit preferably having a lower end portion terminating within said draft tube and wherein, said draft tube has an outwardly flared lower skirt portion terminating in the bottom portion of said vessel, and preferably including a vent pipe connected to said inlet conduit to reduce foaming generated by the reaction in said vessel and to prevent blockage of said inlet conduit, and including means for applying air, under pressure, to the bottom of said reactor and/or under the bottom of said lower skirt portion, to prevent settling of undissolved solids.

Claims18

Dependent claims

Apparatus for reacting a particulate solid and a liquid, said apparatus comprising:

(a) vessel means for containing the particulate solid and the liquid;
(b) mixing means for circulating the particulate solid and the liquid within said vessel means, said mixing means including a draft tube disposed in a vertical position within said vessel means, and an agitator positioned within said draft tube, said draft tube having an outwardly flared lower skirt portion terminating in the bottom portion of said vessel means and said agitator including a propeller and a drive shaft connected therewith, said drive shaft being coaxially mounted within said vessel means and extending into said draft tube;
(c) inlet means for introducing the particulate solid and the liquid into said vessel means draft tube having an outwardly flared lower skirt portion terminating in the bottom portion of said vessel means;
and,
(d) a source of gas and at least one gas injection means connected thereto for preventing appreciable settling of solids within the vessel means, said gas injection means extending into said outwardly flared lower skirt portion of said draft tube.

2 more elements

An apparatus for the production of phosphoric acid by the reaction of phosphate rock, sulfuric acid and phosphoric acid, said apparatus comprising at least a first reaction vessel and a second reaction vessel interconnected with piping for the simultaneous transfer of slurry between the first and second reaction vessels, each reaction vessel having a draft tube extending vertically therein and having an outwardly flared lower skirt portion terminating in a bottom portion of each reaction vessel whereby an annulus is created between the reaction vessel and the draft tube, and a propeller agitator positioned within each draft tube and mounted on a shaft extending vertically and axially of each reaction vessel, the first reaction vessel having an inlet means connected to a source of a phosphate rock slurry for the introduction of phosphate rock slurry to the first reaction vessel and the second reaction vessel having an inlet means connected to a source of sulfuric acid for the introduction of sulfuric acid to the second reaction vessel, the improvement in the apparatus comprising an inlet conduit means on the first reaction vessel extending into the draft tube in the first reaction vessel, the inlet conduit means having an essentially vertical portion within the first reaction vessel, an external upper vent portion vertically extending above the first reaction vessel connected at an angle to the vertically extending upper vent portion for introducing a feed slurry of phosphate rock to the first reaction vessel;

at least one gas introducing means for introducing a gas to the bottom portion of at least one of the first and second reaction vessels and below the outwardly flared lower skirt portion of the draft tube in said reaction vessel, said gas introducing means being operative for providing a sufficient fluid velocity for suspending solids present in each reaction vessel and preventing appreciable settling of solids;
and in said second reaction vessel, a second inlet conduit means connected to a source of sulfuric acid for the introduction of sulfuric acid in the second reaction vessel.

Dependencies are inferred from the claim text.

Apparatus for reacting a particulate solid and a liquid

Life of this patent

Apparatus for reacting a particulate solid and a liquid

Life of this patent

Abstract

Claims18