Production of highly soluble foliar fertilizer in a spouted bed dryer

The drying process can be useful to change the particulate structure, improving the powder solubility. In this study, we investigated the drying of foliar fertilizer in a spouted bed using polyethylene pellets as inert particles to improve its solubility. A 2³ factorial experimental design was used to evaluate how the powder yield and moisture were affected by the feeding time, intermittency time, and feed atomizer position. The spouting instability caused powder retention on the bed wall, which decreased the powder recovery efficiency by 2.3-26.6%. Although the powder recovery efficiency was low, the solubility time was reduced by 5.9 times, probably due to particle agglomeration, which increased the amorphous phase of the fertilizer. Design alterations, suggested by the CFD data, can increase spouted bed stability and facilitate centralized spouting. Based on this, the spouted bed drying technique was applied, and it effectively increased the solubility of commercial fertilizer, thus, incorporating more desirable characteristics for field applications.

Index terms:
Drying pastes; inert particles; LDPE; solubility; CFD.

Authorship

Ana Carolina Ribeiro Stoppe

Methodology design

Data collection

Data analysis and interpretation

Writing and editing

Universidade Federal do Triângulo Mineiro/UFTM, Programa de Mestrado Professional em Inovação Tecnológica/PMPIT, Uberaba, MG, BrasilUniversidade Federal do Triângulo Mineiro/UFTMBrazilUberaba, MG, BrazilUniversidade Federal do Triângulo Mineiro/UFTM, Programa de Mestrado Professional em Inovação Tecnológica/PMPIT, Uberaba, MG, Brasil

http://orcid.org/0000-0002-4744-0738

Mario Sérgio da Luz

Data analysis and interpretation

Writing and editing

http://orcid.org/0000-0003-1226-9480

José Luiz Vieira Neto

Methodology design

Data analysis and interpretation

Universidade Federal do Triângulo Mineiro/UFTM, Departamento de Engenharia Química/DEQ, Uberaba, MG, BrasilUniversidade Federal do Triângulo Mineiro/UFTMBrazilUberaba, MG, BrazilUniversidade Federal do Triângulo Mineiro/UFTM, Departamento de Engenharia Química/DEQ, Uberaba, MG, Brasil

http://orcid.org/0000-0003-0736-3974

Kássia Graciele dos Santos ^**Corresponding author: kassia.santos@uftm.edu.br

Conceptual Idea

Methodology design

Data analysis and interpretation

Writing and editing

http://orcid.org/0000-0001-7452-6900

^*Corresponding author: kassia.santos@uftm.edu.br

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables | Formulas

Figures (7)
Tables (3)
Formulas (6)

Spouted bed geometry	Experimental conditions used in CFD simulations
D₀ = 0.05 m	Particle density 878 kg/m³
D_i = 0.02 m	Particle diameter 0.004 m
H_co = 0.125 m	Particle loading 1 kg
H_co = 0.73 m	Voidage 0.39
D_c = 0.12 m	Air low rate (Q_{1.5 ms}) 120 m³/h
H₀ = 0.225 m	Time step 1 x 10^-3 s

Experiment	Factors			Responses
Experiment	t_{F [s]} (x₁)	t_{I [s]} (x₂)	H_a[m] (x₃)	h [g/g]	M [%]
1	10 (-1)	60 (-1)	0.40 (-1)	0.089	9.06
2	30 (+1)	60 (-1)	0.40 (-1)	0.076	9.77
3	10 (-1)	300 (+1)	0.40 (-1)	0.029	8.93
4	30 (+1)	300 (+1)	0.40 (-1)	0.023	9.48
5	10 (-1)	60 (-1)	0.68 (+1)	0.182	20.56
6	30 (+1)	60 (-1)	0.68 (+1)	0.252	21.78
7	10 (-1)	300 (+1)	0.68 (+1)	0.066	20.25
8	30 (+1)	300 (+1)	0.68 (+1)	0.049	21.44
9*	30 (+1)	60 (-1)	0.68 (+1)	0.266	20.53

Responses	Factor	Effect	Deviation	p-level
>h [g/g] (R²= 0.939)	mean	0.100	0.010	0.000
	x₂	-0.116	0.020	0.002
	x₃	0.091	0.020	0.006
	x_{2 ×}x₃	-0.060	0.020	0.030
>M [%] (R²= 0.999)	mean	15.074	0.135	0.000
	x₁	0.747	0.270	0.032
	x₃	11.527	0.270	0.000