Two
ovens, processing two
retorts, are combined into one module.
Ideally, the two
retorts are operated in counter-phase: 1 retort heating and drying, 1
retort carbonising. The vapour released from the second retort provides
process heat to the first retort. After carbonisation has been
completed in the second retort, that retort is replaced by a fresh one.
The first retort enters the carbonisation phase, and the vapour
released provides
process heat to the second retort. This continual
batch process is sometimes called a tandem
system or a system of twin
retorts.
In reality, the
balance between the two ovens/retorts occasionally gets lost,
e.g. if moisture contents of feed materials vary, or if material sizes
are
out of specs. The bio-oil by-product then provides the required process
heat. To this end a special bio-burner is used equipped with FLY™ technology.
Valves
control the flows
of hot exhaust gas from the vapour burner and bio-oil burner.
Combustion is complete, so that emissions are well within allowable
boundaries.
A
small Condensing Retort plant consisting of two modules (each with two
ovens)
