US 12,128,379 B2
Fluidized bed granulator or fluidized bed/spouted bed granulator
Keishi Sano, Narashino (JP); Genshi Nishikawa, Narashino (JP); Kimihito Haruta, Narashino (JP); Katsunori Yagoh, Narashino (JP); Masashi Takahashi, Narashino (JP); Yuichiro Wakashima, Narashino (JP); Keiji Mase, Tokyo (JP); Shozo Ishibashi, Tokyo (JP); and Tetsuya Kawabe, Tokyo (JP)
Assigned to TOYO ENGINEERING CORPORATION, Tokyo (JP)
Appl. No. 17/909,149
Filed by Toyo Engineering Corporation, Tokyo (JP)
PCT Filed Feb. 8, 2021, PCT No. PCT/JP2021/004616
§ 371(c)(1), (2) Date Sep. 2, 2022,
PCT Pub. No. WO2021/176959, PCT Pub. Date Sep. 10, 2021.
Claims priority of application No. 2020-037641 (JP), filed on Mar. 5, 2020.
Prior Publication US 2023/0088680 A1, Mar. 23, 2023
Int. Cl. B01J 2/16 (2006.01)
CPC B01J 2/16 (2013.01) 12 Claims
OG exemplary drawing
 
1. A fluidized bed granulator or fluidized bed/spouted bed granulator into which urea seed particles, an aqueous urea solution and air are introduced to produce urea particles with an average particle size (according to sieve analysis test method JIS Z8815, ASTM E11) of 1 mm or more,
the fluidized bed granulator or fluidized bed/spouted bed granulator including a box-shaped granulation chamber comprising a bottom floor, a top surface facing the bottom floor and side surfaces between the bottom floor and the top surface, and including a bottom surface facing the bottom floor on the opposite side of the top surface,
wherein inner wall surfaces of the granulation chamber are formed of a metal material, the top surface or an upper part of the side surfaces includes an exhaust outlet, the side surfaces or the top surface includes an inlet for introducing the urea seed particles, the side surfaces include an outlet for the urea particles, the bottom floor or the side surfaces include inlets for introducing the aqueous urea solution, and the bottom floor or the bottom floor and the side surfaces include inlets for introducing the air,
at least a portion of the inner wall surfaces of the granulation chamber is treated by surface roughening, the portion of the inner wall surfaces including a first roughening-treated surface and a second roughening-treated surface which are treated as two different types of roughening-treated surface forms with respect to each other, and
either the first roughening-treated surface or the second roughening-treated surface has an arithmetic average roughness (Ra) (JIS B 0601:1994) of peaks and valleys in the surface treated by surface roughening is 0.35 to 5.0 μm and an average distance between local peaks(S) (JIS B 0601:1994) of the peaks and valleys is 2 to 300 μm.