Monitoramento das transições de regime em um leito de jorro empregando a análise wavelet
Arquivos
Data
2022-02-01
Autores
Silva, Talita Cerqueira 
Maranhão, Vinicius Trindade
Orientadores
Silva, Carlos Alexandre Moreira da
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O leito de jorro surgiu como uma adaptação do leito fluidizado, mas diferente
deste, a velocidade do ar gera um movimento ordenado e cíclico, que se assemelha
ao de uma fonte de jardim. Tal operação unitária apresenta grande interesse por
proporcionar uma intensa transferência de massa e calor, tornando-a altamente
versátil, sendo muito empregada na indústria farmacêutica, de alimentos, química e
agrícola. Infelizmente o leito de jorro apresenta dificuldades em sua operação em
larga escala, devido aos problemas associados a determinação e controle de seus
regimes fluidodinâmicos. Em função disso, este trabalho visou compreender e
identificar os regimes fluidodinâmicos do leito de jorro, com base nos experimentos
preliminares realizados por Butzge (2012) e utilizando-se processamento de sinais
via a análise Wavelet. Existem diversas técnicas de processamento de sinais. A
análise espectral transforma os sinais do domínio do tempo para o da frequência e a
análise wavelet decompõe o sinal original em diversos sub-sinais, possibilitando
assim o acesso a informações que não são facilmente observadas no sinal original
por análise espectral. Foram realizadas análises sob os dados de flutuação de
pressão em leito seco, com partículas de vidro que possuem diâmetros entre as
faixas de 1,4 a 1,68mm e 2,4 a 2,6mm. Além disso, foram utilizadas no leito massas
de 300 , 600 , 900 e 1200 g. A combinação entre os diâmetros das diferentes
massas de leito geraram oito ensaios de flutuação de pressão que foram tratados
inicialmente utilizando-se a análise espectral e posteriormente a análise wavelet. Os
ensaios foram realizados aplicando-se uma variação de voltagem aos inversores que
assim aumentavam a intensidade de vazão do gás, gerando diferentes sinais de
pressão que foram utilizados neste trabalho. Notou-se alguns padrões de regime por
análise espectral, sendo esta muito acertiva para a identificação dos leitos fixos e
rompimento do jorro. No caso do regime de início do jorro, pequeno jorro, jorrinho e
movimento circular, a melhor forma de identificação dos regimes foi a observação
concomitante das duas análises. As instabilidades no jorro foi o único
comportamento observado de forma nítida apenas na análise wavelet.
The spouted bed emerged as an adaptation of the fluidized bed, but different from that, the air velocity generates a movement that resembles that of a source. This unitary operation is a great interest for providing an intense transfer of mass and heat, making it highly versatile and can be used in the pharmaceutical, food, chemical and agricultural industries. Unfortunately, the spouted bed presents difficulties in large-scale operation due to the problems associated with determining and controlling its fluid dynamic regimes. With that in mind, this work aims to understand and identify the fluid dynamic regimes of the spouted bed, based on experiments carried out by Butzge (2012) and using Wavelet analysis. There are several signal processing techniques, highlighting the Spectral Analysis, which transforms signals from the time domain to the frequency domain, and the Wavelet Transform, which is a signal processing technique that decomposes the original signal into sub-signals, thus enabling access to information that is not easily observed in the original signal. The analysis was carried out under the pressure fluctuation data in a dry bed, with glass particles with diameters from 1.4 mm to 1.68 mm and 2.4 mm to 2.6 mm, in addition masses of 300 g, 600 g, 900 g and 1200 g were placed in the bed. The combination between the diameters of the different bed masses generated eight signal tests that were initially treated using Spectral Analysis and later with Wavelet Analysis. The tests were carried out by applying a voltage difference to the inverters that increased the intensity of gas pressure, generating signals that they were used in these cases. Some patterns were noticed when analyzing the graphs generated by both Spectral Analysis and Wavelet Analysis, the first being used to identify fixed beds and bed disruption. In the case of the beginning of the stream, small stream, small stream and circular movement, the best way to identify the regimes is a concomitant observation of the two analyses. The spouted instabilities are the only ones observed clearly only in the wavelet analysis.
The spouted bed emerged as an adaptation of the fluidized bed, but different from that, the air velocity generates a movement that resembles that of a source. This unitary operation is a great interest for providing an intense transfer of mass and heat, making it highly versatile and can be used in the pharmaceutical, food, chemical and agricultural industries. Unfortunately, the spouted bed presents difficulties in large-scale operation due to the problems associated with determining and controlling its fluid dynamic regimes. With that in mind, this work aims to understand and identify the fluid dynamic regimes of the spouted bed, based on experiments carried out by Butzge (2012) and using Wavelet analysis. There are several signal processing techniques, highlighting the Spectral Analysis, which transforms signals from the time domain to the frequency domain, and the Wavelet Transform, which is a signal processing technique that decomposes the original signal into sub-signals, thus enabling access to information that is not easily observed in the original signal. The analysis was carried out under the pressure fluctuation data in a dry bed, with glass particles with diameters from 1.4 mm to 1.68 mm and 2.4 mm to 2.6 mm, in addition masses of 300 g, 600 g, 900 g and 1200 g were placed in the bed. The combination between the diameters of the different bed masses generated eight signal tests that were initially treated using Spectral Analysis and later with Wavelet Analysis. The tests were carried out by applying a voltage difference to the inverters that increased the intensity of gas pressure, generating signals that they were used in these cases. Some patterns were noticed when analyzing the graphs generated by both Spectral Analysis and Wavelet Analysis, the first being used to identify fixed beds and bed disruption. In the case of the beginning of the stream, small stream, small stream and circular movement, the best way to identify the regimes is a concomitant observation of the two analyses. The spouted instabilities are the only ones observed clearly only in the wavelet analysis.