Practically Green
The function of these lids is to provide a gas tight seal for the digester tank and provide mounting points for lid mounted control equipment. Thus one lid design supports many different configurations and enables the gold series digesters to handle the mixing, aerobic, anaerobic and storage aspects of the system - all under one low level, easily maintained structure.
The Gold Series Digester lids are a largely boltless design and represent the culmination of a development programme stretching back as far as 1981. These are state of the art tank closures with phenominal gas tightness and precision porting to enable the digester designer to put all the equipment required for the efficient functioning of the digester on the roof of the plant. Moreover, the lids can be easily and safely removed by four men (paying heed to the standard safety procedures applicable to the system) . No lifting equipment is required to completely expose the tank of slurry which can then be stirred by tractor mounted blender if a major stirring system failure should occur - for instance after a long power failure.
These units have proved to be totally reliable in the past decades and the latest modifications allow operation at Mesophilic Temperatures (37-44 deg.C) and Thermophilic Temperatures (53 -56 deg.C).
The materials of construction provide very high insulation levels, so much so that we have to put anti-skid surfaces on them to prevent slipping accidents on with ice on the lids in frosty weather- the frosty surface is not easily heated above freezing point by the hot slurry in the tank.
The lids are highly resistant to Hydrogen Sulphide and volatile fatty acid decay from the action of bacteria,