Navegando por Assunto "Pneumatic transport"

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Acesso aberto (Open Access)
Análise experimental sobre velocidade de captura em sistemas de transporte pneumático
(Universidade Federal do Pará, 2006) GOMES, Luiz Moreira; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The transport velocity is one of the most important parameters in the pneumatic transport of solids. The success of the particulates materials conveying depends on the prediction or the determination of the minimum velocity of transport. The velocity above of that necessary to the steady transport of solid particles leads to a great energy consumption due to an increased pressure drop of the system, solids degradation and abrasion of solids and of the tube. On the other hand, a velocity below of this boundary-value certainly will result on the deposition of solid particles for bottom of the tube and its consequently blockage. In this work, a technique to measure the minimum pickup velocity of solid particles in horizontal pneumatic conveying has been developed. It is based on visual observation of the particles behavior when occurring the capture, on measures of the velocity of operation of the gas and the mass of captured particles. The qualitative analysis of some parameters is made still that influence in the pickup velocity of particles, allowing a bigger understanding of the involved phenomena.
Acesso aberto (Open Access)
Contribuição à análise do transporte pneumático em fase diluída
(Universidade Federal do Pará, 2011-10) GOMES, Luiz Moreira; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
This thesis is a contribution to the dilute-phase pneumatic conveying analysis. The survey of the key parameters of a pneumatic transport of bulk solids which are: the minimum conveying air velocity and pressure drop in horizontal and vertical pipelines. Therefore, an analysis of the main correlations available in the literature is made focused on the prediction of such critical velocities, and so proposes the use the most reliable correlations. In this way, an equation to predict the pickup velocity of the particles at the bottom of a horizontal pipeline was also developed. Then was analyzed the behavior of the pressure drop due to the solids and system properties using two computer programs, one of them does not consider the pressure drop in the acceleration zone in its formulation (algorithm). So, it is possible to understand what is the contribution of the acceleration zone in the total pressure drop of system and which is the range of application of each program. It is also done through mathematical modeling, the sensitivity analysis of the initial porosity of the bulk solids in the pressure drop along the pipeline as a function of parameters such as: solids mass flowrate, pipeline length, particles density and pipeline diameter.
Acesso aberto (Open Access)
Transporte pneumático fluidizado: estudos de casos aplicados à indústria do alumínio primário
(Universidade Federal do Pará, 2011-08) VASCONCELOS, Paulo Douglas Santos; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
This work is a contribution to science and applied technology developed to fluidized bed and fluidized motion conveying used in the powder handling of the industrial processes. In the case of fluidized bed it is proposed an empirical equation to predict the minimum fluidization velocity for the fluoride alumina, crust powder and others powders used in the industrial processes with good results compared with the experiments and the equations available in the literature. It was also studied the constitutive equations to predict the behavior of the angle of repose and interparticles friction as a function of the superficial velocity of fluidization. In a second step it is proposed an equation to predict the capacity of the Air Pneumatic Fluidized Conveyor with good results compared with the experiments for fluoride alumina. The Air Fluidized Conveyor is a contribution to applied technology reducing the consumption of energy, it operates even in upward direction, and so, decreasing the rate kWh/ton in the powder handling of the industrial processes.