Some operational errors and structural failures may cause
in a black liquor recovery boiler plant explosion leading
to consider-able material damages and to human injuries.
Serious explosions, however, have been rare and the
comparison between the accident frequencies shows that,
for instance, the frequency of smelt-water explosions is
in Finland essentially smaller than in North America. On
the other hand, the black liquor recovery boiler
explosions during the last few years show that the
problem is still actual.
The safety analysis of the plants was started with a risk
mapping applying potential problem analysis. As a result
13 hazards with 78 contributors were found. The pipe
lines, vessels and process equip-ment of the black liquor
recovery plant were then examined in detail using hazard
and operability study (HAZOP). 41 hazards with over 200
contributors were thus identified. For instance, in the
liquor system over 60 cases were identified in which
indadvertent dilution may appear.
Occupational accident risks were sought using work safety
analysis (WSA). Three important operator tasks were
studied - boiler keeper, stoker and evaporation plant
keeper. Altogether 79 hazards with over 100 contributors
were found. The most important problems were connected to
the accessibility of appliances and the walkways used.
Problems and hazards connected to maintenance were sought
by using the MORT-method and action error analysis (AEA).
A total of over 260 different improvements were proposed
as a result of the safety analysis. About one third were
found during the operability study, one third during the
maintenance study and the rest during the risk mapping
and work safety analysis. Over one half of the proposals
were technical in nature.
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Number of pages||76|
|Publication status||Published - 1986|
|MoE publication type||D4 Published development or research report or study|
|Series||Valtion teknillinen tutkimuskeskus. Tiedotteita|
- recovery plants
- black liquor
- risk analysis