Estudo experimental de uma valvula conica para controle da descarga de solidos em leito fluidizado

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Feed valve are essential devices in gas-solid systems, in process as fluidized bed drying, pneumatic transport, coal combustion, biomass gasification and synthesis reactions in fluidized beds. All require a feed valve for the particulate solid to control the mass flow rate entering andlor leaving the processo. This work presents the development and the experimental study of a new solid feed valve design, named cone valve, suitable for controlling mass flow rate of hot solid particles leaving a fluidized bed reactor. The proposed device was connected to the wall of a fluidized bed combustor, allowing mass flow rate control of the hot solid particles leaving the reactor towards a fluidized bed heat exchanger. The developed cone valve has basica11y a central shaft with conical extremity moving inside a tube. Cooling water flows inside this central shaft besides pressurized air injection flowing intemally towards the cone lateral surface. Literature review showed factors that have some intluence on the solid mass flow rate control across the cone valve allowing a statistical ana1ysis procedure in order to identifY the effect of each factor on the processo. The following variables were investigated: ratio between opening arealtransversal tube area at the valve entrance; pressure gradient diference between the valve extremities; particle diameter and temperature of the fluidized bed. Application of a fundamental statistical method for planning the experimental procedure allowed simultaneous study of several variables and the identification of their inBuence on the feeder valve performance. The analysis of results showed that the mass flow rate through the valve has a statistically significant inBuence ftom the factors: ratio between opening area and pipe diameter at the valve entrance and valve pressure diference between the valve extremities

ASSUNTO(S)

escoamento bifasico planejamento experimental fluidização

ACESSO AO ARTIGO

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