The interaction between a single jet and a bed of fluidized solids was investigated with the aim of evaluating a characteristic height of the jetting region corresponding to the distance from the nozzle at which the dispersion of jet momentum is practically complete. A new exptl. technique, based on simultaneous measurements of the static pressure at the bed side wall and on the jet axis and on their elaboration, was used. Various exptl. configurations, based on the combination of two fluidization columns (0.35 and 0.20 m, diam.) and four jet nozzles (6, 10, 19 and 25 mm, diam.), were employed. Glass ballotini of 800-1200 m were used as bed material. The influence of the nozzle gas velocity, of the fluidization velocity, and of the nozzle and the column sizes on the characteristic height of the jet was investigated. This height increases as nozzle gas velocity and nozzle size increase. In contrast, the influence of the fluidization velocity appears more complex and, in particular, cannot be sepd. from that of the nozzle diam. The effect of the column diam. was negligible. Exptl. results were compared with predictions of jet penetration length from literature correlations since the characteristic height shows up evident similarities with the jet penetration length based on momentum dissipation.

Evaluation of the jet penetration depth in gas-fluidized beds by pressure signal analysis

VACCARO, Salvatore;
1997-01-01

Abstract

The interaction between a single jet and a bed of fluidized solids was investigated with the aim of evaluating a characteristic height of the jetting region corresponding to the distance from the nozzle at which the dispersion of jet momentum is practically complete. A new exptl. technique, based on simultaneous measurements of the static pressure at the bed side wall and on the jet axis and on their elaboration, was used. Various exptl. configurations, based on the combination of two fluidization columns (0.35 and 0.20 m, diam.) and four jet nozzles (6, 10, 19 and 25 mm, diam.), were employed. Glass ballotini of 800-1200 m were used as bed material. The influence of the nozzle gas velocity, of the fluidization velocity, and of the nozzle and the column sizes on the characteristic height of the jet was investigated. This height increases as nozzle gas velocity and nozzle size increase. In contrast, the influence of the fluidization velocity appears more complex and, in particular, cannot be sepd. from that of the nozzle diam. The effect of the column diam. was negligible. Exptl. results were compared with predictions of jet penetration length from literature correlations since the characteristic height shows up evident similarities with the jet penetration length based on momentum dissipation.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/3612477
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 22
  • ???jsp.display-item.citation.isi??? 16
social impact