络合铁法脱硫反应器锥段硫磺沉降的数值模拟

Numerical simulation of sulfur deposition in the cone section of chelated iron desulphurization reactor

关键词:  气液固三相流  计算流体力学  欧拉多流体模型  络合铁  脱硫  硫磺沉降 

Key words:  gas-liquid-solid three phase flow  computational fluid dynamics  Eulerian multiphase model  chelated iron  desulphurization  sulfur deposition

摘要:

络合铁法脱硫工艺在天然气行业应用广泛,将反应生成的硫磺富集回收是反应器稳定运行的关键之一。在反应器底部引入锥段对硫磺的富集、沉降和回收很有帮助,为了避免硫磺在锥段侧壁长期沉积和结块,应分层通入扰动气体。通入气量不能太小,以免达不到避免锥段侧壁硫磺沉积的作用；但也不能太大,否则会使得硫磺难于沉降。本研究采用欧拉多流体模型,对锥段硫磺沉降进行了模拟,研究了硫磺浓度和通气速度对硫磺沉降的影响。结果 表明:硫磺浓度对沉降速度影响较小,而通气速度对沉降影响明显。随着气速的增大,硫浆沉降越来越慢,对所研究的体系而言,最大通气速度应小于0.75 m/s。

Abstract:

Chelated iron desulfurization process is widely used in natural gas industry, the enrichment and removal of sulfur particles is a key factor for stable operation of the reactor. The design of a cone section at the bottom of the reactor is helpful for the enrichment, settlement and recovery of sulfur particles. In order to avoid long-term deposition and agglomeration of sulfur particles at the side wall of the cone section, the disturbed gas should be injected at different heights. The flow rate of the disturbed air should not be too small, so as to avoid sulfur deposition at the side wall of the cone section. It should also not be too large, so as to prevent the settlement difficulty of the sulfur particles. Eulerian multiphase model was used to simulate sulfur deposition in the cone section. The effects of sulfur concentration and air flow velocity on sulfur deposition were studied. The results showed that sulfur concentration had little influence on the settling velocity, while the effect of air flow velocity on the settlement was obvious. The deposition rate of sulfur particle decreased with the increasing of gas velocity, the maximum air flow velocity of the system should be less than 0.75 m/s to ensure the settlement of the sulfur particles.