Development And Research On Feeding Nozzle About The Reactor Of Slurry Bed Hydrocracking

The slurry bed hydrocracking technology has some superiorities,such as the process is relatively simple,the conversion is high,and it can deal with the low quality oil which contains high mental,so it has very important position in the refining industry.The reactor of slurry-bed hydrocracking is a very important equipment in the entire hydrocracking process,so the inner fluid flow condition directly affect the reaction process.The feeding nozzle is a fluid tunnel into the reactor for the phases of gas and liquid.The structure of the feeding nozzle has important effect on the flow condition of gas and liquid phases,and also has effect on the distribution condition of gas holdup and liquid circulation velocity.The feeding nozzle of slurry bed hydrocracking reactor is in the condition of submerged jet.For this reason,multi-tubes nozzle is taken as the structure type as the slurry-bed hydrocracking reactor.This article uses the method of computational fluid dynamics and Fluent software,and choose the eulerion multiphase flow and standard k-? turbulence model.Through this numerical simulation method,we can describe the two phases flow process in the inner of the slurry-bed hydrocracking reactor,and obtain the distribution condition of gas holdup and liquid circulation velocity.Through analyzing the distribution condition of the parameters,we can determine the structure type of the feeding nozzle is good or not.Firstly we change the number of nozzles and study the influence of nozzles number on the gas holdup and liquid circulation velocity.As the number of nozzles increasing,the distribution character becomes better.So the six feeding nozzle is taken as the basic type.On the six feeding nozzle,we change the structure parameters including the diameter and angle of nozzle,and then analyze the variation of the gas holdup and liquid circulation velocity,last obtain the better structure parameters of feeding nozzle.The distribution condition of flow parameters has produced some improvements when using the better structure of the six feeding nozzle,but still not very uniform.So the tower feeding nozzle is put forward on the basis of the six feeding nozzle.We compare the two type of the feeding nozzle,and obtain that the tower feeding nozzle has a better distribution character.Then we change the structure parameters of the tower feeding nozzle,including the nozzle diameter、nozzle angle and nozzle arrangement,and analyze the variation of the gas holdup and liquid circulation velocity.Through the distribution characters,it can obtain the best structure parameter of the tower feeding nozzle.