Study of horizontal sonic gas jets in gas–solid fluidized beds

Abstract

Existing jet penetration correlations have all been developed for sub-sonic gas jets and have been found to perform poorly when employed in sonic and supersonic regimes. In the present study, triboelectric probes were used to measure both the penetration depth and expansion angle of sonic gas jets. Experiments were conducted using nozzles of different size and geometry, different particle types, different injection gases, and different fluidization velocities. All these data were used to develop a new, general correlation to predict the penetration depth of sonic gas jets. The effects of these variables on jet expansion angle were also studied.On a développé des corrélations de pénétration de jets existantes pour des jets de gaz subsoniques et on a trouvé que leur performanceétait médiocre dans le cas des régimes soniques et supersoniques. Dans la présenteétude, on a utilisé des sondes triboélectriques pour mesurer la profondeur de pénétration et l'angle d'expansion de jets de gaz soniques. Des expériences ontété menéesà l'aide d'orifices de différentes tailles et géométries, différents types de particules, différents gaz d'injection et différentes vitesses de fluidisation. Toutes ces données ontété utilisées pour mettre au point une nouvelle corrélation générale visantà prédire la profondeur de pénétration des jets de gaz soniques. Les effets des variables susmentionnées sur l'angle d'expansion des jets ontégalementétéétudiés.

Review of Research Related to Fluid Cokers

“…The jet penetration increases with increasing nozzle tip diameter, liquid flow rate, and gas flow rate. It can be predicted by an empirical correlation , or through CFD modeling. , The jet penetration is greatly affected by the nozzle geometry: nozzles that provide a larger jet expansion angle achieve a smaller penetration. ,, In a fluidized bed, the jet expansion angle is about half of its expansion angle in open air. , Atomization gases that have a higher speed of sound will result in larger jet expansion angles …”

“…It is crucial to ensure that the attrition jets do not erode the column wall or bed internals. The jet penetration into the fluidized bed can be predicted either with empirical correlations ,,, or through CFD modeling. , The nozzle geometry affects jet penetration: nozzle tips with a larger expansion angle give jet cavities with a larger angle and a shorter length …”

“…149,152,190 In a fluidized bed, the jet expansion angle is about half of its expansion angle in open air. 193,194 Atomization gases that have a higher speed of sound will result in larger jet expansion angles. 194 Interactions between the jets issuing from different nozzles should generally be avoided.…”

“…193,194 Atomization gases that have a higher speed of sound will result in larger jet expansion angles. 194 Interactions between the jets issuing from different nozzles should generally be avoided. A typical fluid coker may have 50−100 spray nozzles arranged in 5−8 banks at different heights.…”

Measurement technique for the on-line detection of fines in a fluidized bed

“…In order to achieve this objective, triboelectric probes were chosen as the measurement apparatus. Triboelectric probes have been used to monitor solids flow in cyclones [1], in fluidized beds [2], and in jets in fluidized beds [3]. The present study adapts these methods to the on-line monitoring of the proportion of fines in a fluidized bed.…”