Digester vessel to make methane from liq. manure - has overflow with upstream vertical leg to build head pressure to shift blockage

摘要

Digester vessel in which liq. manure is fermented to generate methane gas etc.. The vessel is of the type in which the level of liq. is automatically controlled by overflow discharge of surplus liq.. The overflow pipe extends downwards from its entry at the surface of the liq. for a distance equal to a substantial part of the total depth of the vessel. Pref. the lower end of the pipe is turned through a 180 deg. 'U'-bend to form a siphon trap leading to the discharge end of the pipe. Pref. an isolating valve is fitted at the discharge end of the overflow pipe. The vessel digests liq. manure to produce methane etc. and to convert the waste into a liq. fertiliser. The danger of blockage of the overflow pipe between additions of fresh manure is practically eliminated. Any crust formed in the 'U'-bend is probably shifted as overflowing liq. falls down the considerable height of pipe between the liq. surface and the 'U'-bend. If no the substantial head which builds up behind the blockage as the pipe fills with liq. will almost certainly clear the passage.