雙螺旋攪拌翼微藻反應器系統之研發

Abstract

The reactor system developed in this research based on the double helical ribbons impeller was constructed and combined together with the parts of the outer cover unit, the cultivating tank, the stirring device and the automatic control system. The automatic control system was integrated with the pH value feedback control unit, the solution inlet and outlet control unit, the temperature control unit, the illumination control unit and the aeration control unit, and held three operation modes such as the auto-continuous control process, the single control process and the manual control process, respectively. Based on the fundamental performance test, the illumination condition could be changed to 4, 8 and 12 light sources with with the respected illuminance of 2600, 5200 and 6500 lux. The rotation speed of the stirring shaft could be varied using an indirect circuit frequency controller between frequencies 0 and 60 Hz. The valuable range of frequencies obtained was between 0 and 30 Hz, while the related rotation speeds were between 0 and 172 rpm. A regression equation between the relation of rotation speed and frequency was also established, which could be used to set the frequency of the controller as the rotation speed required. During 20 days of the automatic semi-continuous cultivating experiment, the cultivating conditions were set with the illuminance of 6500 lux, the rotation speed of 50 rpm, the pH value of 7±0.5, the temperature of 25℃, the daily dilution ratio of 16.67% (20/120), the daily inoculate rate of 5:1 (83.33%) and the valid cultivating volume of 120 1. The experimental results showed that the reactor system could produce a high concentration solution of the algal cell. The daily harvested amount of the algal cell solution was 20 liters with the average harvesting concentration 667.27×10^4 cells/ml, and the average concentration of the algal cell after dilution was about 443.97×10^4 cells/ml. The daily average growth rate constant and the daily average impeller energy consumption obtained were 0.3997 day^(-1) and 1.21kwh, respectively. The experiment also verified that the reactor system presently developed in this research obtained the capabilities of stable and long-term cultivating functions for the alga Isochrysis aff. galbana.本研究旨在設計開發一套使用雙螺旋攪拌翼之微藻反應器系統，製作完成之系統主要由外部遮蔽本體、培養槽體、攪拌裝置及自動控制系統所構成，其中控制系統包括pH迴饋控制、進排液控制、溫度控制、光照及曝氣等單元，具備自動連續、單動及手動控制模式。經由基本性能測試，獲致開啟4、8與12只植物燈光照強度分別為2600、5200與6500 lux；攪拌軸轉速於變頻控制在0-60Hz，獲致實際可操作之變頻範圍在0-30Hz之間，其相對應之轉速則介於0-172rpm，並經迴歸分析獲致其變頻數值與攪拌軸轉速之數學關係式，進而可依據此關係式獲得設定轉速之變頻值。系統自動化半連續之自動循環模式培養試驗，在光照強度、pH值、溫度與攪拌軸轉速設定分別為6500 lux、7.0±0.5pH、25℃與50rpm（變頻數值8.7Hz），並以稀釋率16.67%(20/120)、接種比例5:1(83.33%)與有效培養水體120公升條件下，連續培養20天之測試結果，顯示本反應器系統可生產高濃度之藻細胞，並獲致每日收穫定量平均濃度約為667.27×10^4 cells/ml之藻體溶液20公升，而其稀釋後平均濃度則約為443.97×10^4 cells/ml，且單日生長速率常數與攪拌翼能量消耗平均約為0.3997day^(-1)與1.21kwh，亦顯示本研究之藻類反應器已具備穩定且可長時間培養大溪地等鞭金藻之能力