• Records on breakdowns and their causes. By means of previously recorded
breakdowns it is easier to compare the breakdowns and detect the reasons for
failure.
Beyond this, there are various institutions, associations and companies which carry out
series of measurements for different kinds of biogas plants. These series of measurements,
records and evaluations analyze errors with the objective to disseminate and optimize biogas
technology as well as to avoid mistakes of the past.
Repair
Breakdowns which might appear when operating biogas plants are described in the
following. The most frequently occurring disturbance is insufficient gas production which can
have a variety of different reasons. Sometimes observations and experiments might take
weeks until a perfect solution is found.
Disturba
nces
Possible reasons
Measures to be taken
blocked fibrous material inside the pipe or cleaning up the pipe with a pole; removing
inlet/outle sinking layer blocking the lower sinking layer by frequent ’poking’ through
t pipe end of the pipe
inlet and outlet pipe.
floating
drum is
stuck
swimming layer
turn the dome more frequently; if turning not
possible, take off the dome and remove the
swimming layer
broken guiding frame
weld, repair and grease guiding frame
sinking
sludge
level
digester not water-tight
if cracks in the digester do not self-seal
within weeks, empty digester and seal
cracks;
insufficie
nt gas
storage
gas store not gas-tight due to
cracks or corrosion
seal cracks, replace corroded parts;
blocked
taps
corrosion
open and close several times, grease or
replace taps;
gas pipe
is not
tight
corrosion or porosity; insufficient
sealing of connections;
identify leaking parts; replace corroded or
porous parts; re-seal connections
sudden
gas loss
8. crack in the gas pipe
9. automatic water trap blown
empty
10. open gas tap
4. repair or replace
5. add/refill water, detect reason for
over-pressure; check dimensioning
of the water-trap
6. close tap
throbbing
gas
pressure
1. water in the gas pipe
2. blocked gas pipe
1. check functioning of water trap;
install water traps in depressions of
piping system or eliminate these
depressions;
2. identify the blocked parts (start with
gas outlet, connections to
appliances and bends); clean the
respective parts;
Repair measures are being taken in case of acute disturbances or during routine
maintenance work. Repair measures which go beyond routine maintenance work have to be
carried out by specialists, since the biogas plant owner in most cases does not have the
required tools and the necessary technical know-how. In any case, annual maintenance
service should be carried out by a skilled biogas technician.
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