Hydrodynamics Of Gas Flow Rate Changes In Three-phase Slurry Reactor And In Sewage Treatment

Slurry bubble column reactor (SBCR) has been widely used in a number of chemical, biochemical and environmental processes, because of its superior characteristics of heat transfer, mass transfer and flexibility of operation.The hydrodynamic behavior plays an important role in the design, scale-up and operation process of SBCR. However, in many research, researchers tend to believe that the gas mass and flow rate have no change from bottom to top in SBCR. On the contrary, in the actual chemical reactions take place in SBCR, and gas will be consumed and produce other products. Thus, different reactions will change the gas mass and flow rate, so that the conclusions obtained from the research are difficult to apply to actual production. Therefore, it is necessary to study the changes of gas mass and flow rate in the cold model experiments. The main purpose of this paper is to establish a way in the cold model experiment to achieve gas mass and flow rate variation, in this case, we can study the changes of hydrodynamic properties, and theoretical data will be obtained to optimize the reactor, at last, in reality examine the effect of the SBCR.This paper conducts the research on how the C02-NaOH solution system that are constitute of superficial velocity, solid holdup and gas distributor have impacted the distribution of gas holdup which takes place in a two meter high and double-layer constructed slurry bubble column reactor. On the other hand, subject use the gas distributor which has the gas riser, in order to make the gas in the reactor for reactor for better distribution. Gas riser can inject the fresh gas into the central location of the reactor; it also improved space utilization efficiency of the reactor. Experimental results show the riser gas distributor applies to the situation of higher superficial gas velocity, and with the opening ratio increase, vertical gas holdup increased.According to the experience of this research, we have improved the SBCR, and applied the reactor into the biologic tri-phase fluid bed technology, and the results are as follow:First, the change in COD concentration with time showed a downward trend, with the increase air flow rate to reduce. It was shown that good COD removal effect had been gotten. Second, NH3-N removal rate reached 94.4%.