Study On The Illumination Characteristics Of A New Type Of Tubular Photobioreactor With Built-in Combined Rotor

Energy plays an important role in today's social and economic development,and the traditional fossil energy is forcing people to develop new energy gradually because of its quantity and environment.The research of new energy in China is mainly concentrated on tidal energy,solar energy,nuclear energy,wind energy,biomass energy and so on.At present,such as wind power,hydropower and others already have a relatively mature technology base,and biodiesel in biomass energy has become an important direction in recent development because of its direct use of existing equipment.Microalgae have the characteristics of low culture cost,easy growth and high oil content,and gradually become one of the most suitable materials for the preparation of biomass energy.Compared with the open cultivation of microalgae,enclosed culture like photobioreactor with high density cultivation,easy control and high health conditions by the majority of scholars,and the tubular photobioreactor has been widely attention because it has the illumination area ratio,easy construction and low cost,but there are still problems like gas poor mixing,light dark cycles,and the most importantly is growing in wall and the shading phenomenon is serious.In this paper,introducing the technology of cultivation Chlorella,optical biological reactor types and the factors affecting the cultivation of Chlorella,and joined combination rotors in traditional tubular photobioreactor.On the one hand,it enhance the mixing effect of gas and liquid inside the tube,and the Chlorella will fast get into the logarithmic phase,and on the other hand,because it makes strong of Chlorella algae the degree of fluid turbulence,aggravation of pipe wall impact,which slow down the phenomenon of wall adherence growth,due to the rotation of rotors it increases the radial fluid flow in the tube of algae,which greatly improves the light dark cycle of Chlorella.This paper designed and built a small combined rotors tube photobioreactor,preliminary experiments showed that Chlorella optical density,and the specific growth rate was higher than that of light tube culture after adding rotors.In addition,the OD value and specific growth rate in the 18:6 light dark cycle group were higher than 17.1%and 0.66%with the 24:1 light dark cycle control group.Therefore,the combined rotors have a positive effect on the culture of Chlorella,and it is also beneficial to the growth of Chlorella.Through preliminary experiments,a vertical combined rotors tubular bioreactor was designed and built,and the relationship between flow rate and rotors speed was fitted by MATLAB software.The effect of combined rotors speed on microalgae culture was obtained.The rotors speed is 270RPM,than the rotors speed was 148RPM value,specific growth rate and biomass were 37.07%,12.3%and 38.4%higher.