| 摘要 |
<p>Within the digester in which anaerobic fermentation takes place, the liq. effluent is passed through a filter, pref. a microfilter. The filter is pref. adjacent to the effluent outlet. For microfiltration the filter perforations are pref. of a dia. between about 50 and 500 microns. - Pref. the digester is of the vertical cylindrical, upflow type. The filter is pref. a coaxial, annular screen of upwardly convergent conical section fitted above the fermenting liq. A rotary horizontal scraper is pref. employed to sweep floating solids from the surface of the liq. into a collection duct discharging outside discharging outside the digester. - The filter perforations do not allow the biomass to leave the digester. Previously, biomass material was entrained in effluent from the digester and has to be sepd. by decanting for recycling. Apart from the work involves in decanting and recycling, there was an inevitable loss of biomass material.</p> |
