EGSB反应器布水装置进水方向对内部流场的影响

Effect of Water Distributor's Inlet Direction on Flow Field in EGSB Reactor

针对传统厌氧膨胀颗粒污泥床(EGSB,expanded granular sludge blanket)反应器布水装置进水不均匀、搅拌不充分以及存在较大死区等缺点,提出周向进水的布水方式,采用欧拉-欧拉模型建立EGSB反应器内两相流计算流体力学模型,模拟常规布水装置与周向进水装置下反应器的流动状态;通过改变进水管头数量来控制进水流速,模拟不同进水流速下反应器内部流场的流动状态。模拟结果表明周向进水反应器具有更好的泥水混合效果和更高的膨胀床层,周向进水结构能够达到搅拌目的的最小流速为0.555 m/s。周向旋流式进水方式较传统轴向布水方式能使反应器内介质更充分混合,增加泥水接触面积,提供更有利于生化反应的流态。

According to the disadvantages of uneven water distributing uniformity,inadequate mixing and large dead zone of traditional water distribution device in EGSB reactor,an circumferential water distribution mode was proposed. An Eulerian-Eulerian two-phase solid-liquid flow model was formulated to simulate reaction zone hydrodynamics in an EGSB reactor with traditional water distribution and circumferential water distribution condition. By changing the numbers of the water inlet pipes the flow velocity was controlled,reaction zone hydrodynamics in reactor with different inlet flow velocity was stimulated. The simulation results show that the reactor with circumferential water distribution has better sludge mixing effect and higher sludge expand level,and the minimum flow rate of the mixing flow can be achieved by the circumferential device is 0. 555 m / s. Comparing with the traditional axial water distribution mode, the circumferential water distribution mode can make the reactor more fully mixed,and increase the contact area of sludge and water,and provide the flow regime which is more favorable to the biochemical reaction.