Seal testing (see
chapter 7.1 for
details)
• water in mixing pit
• water in displacement pit
for floating-drum plants:
• water loss < 2%
Gasholder (of
floating- drum
plants only)
Gas valves
Gas pipe
Gas appliances
• water loss > 10% for fixed-
dome plants:
• water loss < 2%
(pressureless) > 10%
• water loss < 5 %
(pressurized) > 10%
•false dimensions,wrong
• grade of steel,
• faulty welds
• faulty painting
• stuck valves
• missing valves
• false water trap
• false gradient
• leak found upon pressure
testing
• poor workmanship
• functional defects
• lengthen the outlet
• alter the elevation of the
a) gas outlet
b) displacement pit
• alteration too much trouble
• alteration too much trouble
• acceptable as is
• repair masonry
• acceptable as is
• repair masonry
• acceptable as is
• repair masonry
• reject gasholder,
build new one
• repair welds
• repaint
• repair or replace
• re-install
• repair leaks
• re-install
• repair or replace
In case of doubt, locate and repair
all defects, even if it seems like a
lot of trouble at the moment;
repairs at a later date would be
more troublesome!
Check carefully; defects most
likely in the gas system
7.2 Plant operation
The operation of a simple biogas plant is relatively uncomplicated. The user must be given all the
information and practical assistance he needs before and during the early phases of plant
operation.
Collecting substrate
The collection of substrate is a simple matter when combined with work that has to be done
anyway, e.g. cleaning the stables. It can be made even easier by arranging for the manure to flow
directly into the mixing pit. Experience shows that it is not a good idea to gather dung from fields,
roads, etc. or to go to the trouble of elaborately chopping up or otherwise preprocessing plant
material for use as substrate. The work involved is usually underestimated, while the motivation is
overestimated.
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