Experimental Investigation on the Pulse Flow Regime Transition of Gas–Liquid Concurrent Downward Flow through a Sieve Plate Packed Bed

Abstract

Nine sets of packings were designed to study the pulse flow that occurs in gas−liquid concurrent flow downward through sieve plate packing. Through the observation of flow pattern and the analysis of the pressure fluctuation data acquired by pressure transducers, the mechanisms for the inception and the propagation of pulse flow in the plate packing were clarified, and a variation coefficient method was proposed to determine the boundary lines of the pulse flow. Accordingly, the pulse flow pattern maps were obtained and the effects of the geometric parameters and the installation method of the plate packing on the transition of the pulse flow were analyzed in detail, revealing that the hole diameter and plate quantity have the most evident effects. Finally, correlations for the onset and the disappearance lines of the pulse flow regime were developed, with the deviations from the experiments of ∼15% and 10%, respectively.

Comparative study of dry pressure drop and flow behaviour of gas flow through sieve plate packing

“…Sieve plate packing is a newly developed structured packing and has been successfully applied in nuclear wastewater treatment in the boron recycling system (TEP system). [1][2][3] Compared with conventional packing, sieve plate packing performs better in many respects. First, the simple structure of the sieve plate significantly reduces the manufacturing costs and makes it easy to maintain the packing.…”

“…[2] Second, the sieve hole is large enough so the packing does not get easily blocked. [1,4] Most importantly, the sieve plate can repeatedly enhance the contraction and expansion of the fluid so that the gas-liquid interface can be renewed frequently to improve the transport efficiency. [1] In particular, in the gas stripping tower of the TEP system, three sections of sieve plate packing are used.…”

“…[1,4] Most importantly, the sieve plate can repeatedly enhance the contraction and expansion of the fluid so that the gas-liquid interface can be renewed frequently to improve the transport efficiency. [1] In particular, in the gas stripping tower of the TEP system, three sections of sieve plate packing are used. The gas flows upward and the liquid is fed from the top of the tower; however, the gas and liquid concurrently flow downward through each sieve plate packing, as shown in Figure 1.…”

“…The gas flows upward and the liquid is fed from the top of the tower; however, the gas and liquid concurrently flow downward through each sieve plate packing, as shown in Figure 1. [1] In this flow mode, the driving force of transfer is between the concurrent and countercurrent flow modes. Therefore, the gas stripping tower can provide high separation efficiency and throughput under low-pressure drop and no liquid flooding.…”

“…In addition, there are many other scholars who studied pressure drop and the flow field of single gas flow through columns with complex interiors using CFD simulation. [11,16,[22][23][24][25] However, all of these simulations F I G U R E 1 Degassing unit of the TEP system [1] were focused on compact sheet packing or tray columns and no studies involved the flow behaviour of gas flow through sieve plate packing.…”