Abstract: A continuous process for producing ethanol by fermenting carbohydrate containing feed stocks at atmospheric pressure in a fermentor, in which a fermentation liquor stream is withdrawn from the fermentor, a yeast concentrate is recovered from said stream both recycled to the fermentor and the yeast-free remainder treated to remove ethanol and leave a stillage stream, a large portion of which is recycled to the fermentor, enabling high concentration of fermentable material to be supplied to the fermentor and reducing the amount of water required for the process.

Abstract: This invention relates to a process for producing ethanol by continuous fermentation of polysaccharide-containing raw materials. The fermentation is carried out in one or several fermentors, a stream of fermentation liquor being separated into a yeast concentrate stream and a yeast-free stream, and possibly one sludge stream, of which the yeast concentrate stream is recirculated to the fermentor, at least part of the yeast-free stream being fed to a simple evaporator unit, corresponding to one or a few distilling stages, wherein it is separated, partly into a first vapor stream, enriched in ethanol, which is fed to a plant for production of the desired ethanol grade, and partly into a first liquid bottom stream, which is at least in part recirculated to the fermentor.

Abstract: An evacuable casing for a rotor machine comprises a cover surrounding the machine, bearing means mounting the cover for rotation on a foundation, the cover having an endless base edge, and sealing means extending along the base edge to seal against the foundation when a vacuum is applied within the cover. One part of the cover is mounted for movement relative to a second part of the cover to form a large opening in the cover, this opening in combination with said rotation of the cover on the foundation providing easy access to the machine from any radial direction.

Abstract: In the production of ethanol in plants, comprising a fermenter, a centrifugal separator for the recirculation of the yeast to the fermenter and a plant for the separation of a yeast-free flow, coming from the centrifugal separator, into one flow, rich in ethanol, and into one residual flow, the substrate, that is fed to the fermenter must be rid of solid substance, like fibres etc. In the separation of such solid substance a certain amount of substrate has been lost according to the methods utilized hitherto, or an unnecessarily high consumption of water and energy has occurred. According to the invention the solid substance, which is separated from the raw material flow, is washed, preferably countercurrently with said residual flow, which in turn, enriched in substrate, is fed to the fermenter. If a distillative method is used for said separation the residual flow is called slop.