Multi-nozzle for granulation and method for manufacturing granular product

Abstract

The present invention provides a granulation method with increased drying effect while assuring the pressure for spraying the aqueous solution and the necessary number of nozzles equivalent to those of conventional design. Specifically, the granulation method uses a granulator structured by a fluid bed which fluidizes the granulating-particles, an air feed pipe to introduce air, a nozzle for spraying the raw material aqueous solution being located at center part of the air feed pipe, and a perforated plate to feed a fluidization air to the fluid bed, thus granulating the raw material aqueous solution by spraying thereof from the nozzle into a granulation part, wherein a multi-nozzle in a specified shape having a plurality of nozzle ends thereon is used as the nozzle for spraying the raw material aqueous solution.

Description

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows the shape of the multi-nozzle according to the present invention. FIG. 1(a) is the plan view thereof, and FIG. 1(b) is the front view thereof. The code 300 means a multi-nozzle, 301 means the body in a triangular cone shape and 302 means the nozzle end in a triangular cone shape.

FIG. 2 shows the spraying angle of the multi-nozzle according to the present invention.

FIG. 3 shows a cross sectional view of an embodiment of the granulator of spout-fluid bed type, adopted as an example of the present invention. The code 1 designates a granulator, 2; a feed port of the seed particles, 3; the nozzle, 4; an air heater for a spouting bed, 5; an air feed pipe, 6; a space, 7; an upper part of a fluid bed, 8; the fluid bed, 9; an air heater for the fluid bed, 10; a bed bottom, 11; a discharge port for the granules, 12; a vent port, and 13; an upper part of the air feed pipe.

FIG. 4 shows a general flow diagram for manufacturing granular urea using the granulator.

Claims

1. A multi-nozzle as a nozzle for spraying a raw material aqueous solution, being applied to a granulation method to manufacture granules from the raw material aqueous solution using a granulator of spout-fluid bed type, wherein: (1) two to six nozzle ends in a shape of triangular cone convexed upward are arranged radially on a body in a shape of triangular cone convexed upward at an equal spacing therebetween;(2) spraying angle of each nozzle end is in a range from 15° to 45°, and spraying angle of the whole multi-nozzle is in a range from 30° to 60°; and(3) throughput of the multi-nozzle is in a range from 0.6 to 2.0 t/hr, and throughput of each nozzle end is in a range from 0.1 to 0.4 t/hr.

2. A method for manufacturing granular product using a granulator structured by a fluid bed which fluidizes granulating-particles, an air feed pipe to introduce air, a nozzle for spraying a raw material aqueous solution being located at center part of the air feed pipe, and a perforated plate to feed a fluidization air to the fluid bed, thus granulating the raw material aqueous solution by spraying the raw material aqueous solution from the nozzle for spraying the raw material aqueous solution into a granulation part, wherein the nozzle for spraying the raw material aqueous solution is a multi-nozzle in which: (1) two to six nozzle ends in a shape of triangular cone convexed upward are arranged radially on a body in a shape of triangular cone convexed upward at an equal spacing therebetween;(2) spraying angle of each nozzle end is in a range from 15° to 45°, and spraying angle of the whole multi-nozzle is in a range from 30° to 60°; and(3) throughput of the multi-nozzle is in a range from 0.6 to 2.0 t/hr, and throughput of each nozzle end is in a range from 0.1 to 0.4 t/hr.

3. The method for manufacturing granular product according to claim 2, wherein the raw material aqueous solution is a urea aqueous solution having 90% by weight or more of urea concentration.

4. (canceled)