Abstract: The gas-liquid distributor is an important internal component of up-flow liquid phase hydrogenation reactor, generally with porous plate distributors with multi-group gas-liquid riser tubes. This article studied the bubble generation performance of cylindrical riser tube and Venturi riser tube by high-speed camera method in an up-flow three-dimensional bed cold model device. Furthermore, the effects of superficial gas and liquid velocities on the bubble generation performance of the Venturi riser tube were investigated. The results showed that under the same operating conditions, compared with the cylindrical riser tube, the Venturi riser tube produced more bubbles, and the average diameter of bubbles was smaller, which is more conducive to the uniform distribution of bubbles, so that the bubble generation performance is better. It is found that at the same liquid velocity, as the gas velocity increased, the microbubble fraction increased slightly, the Satue average diameter of bubbles became larger, and the bubble size distribution was wider. While at the same gas velocity, as the liquid velocity increased, the microbubble fraction increased, the Satue average diameter of bubbles became smaller, and the bubble size distribution was narrower.

Key words: liquid phase hydrotreating, up-flow reactor, gas-liquid distributor, gas-liquid riser tube, bubble