Biomedical Engineering Reference
In-Depth Information
TABLE 8.9
Characteristic Sizes of Some Entrained-Flow Gasifiers
Volume
(m
3
)
Reactor External
Diameter (m)
Reactor Internal
Diameter (m)
Reactor
Height (m)
Gasifier
Tennessee
Eastman
12.7
2.79
1.67
4.87
Cool water
17
3.17
2.13
3.73
Cool water
25.5
3.17
2.13
6
Cool water
12.7
2.79
1.67
4.62
Shandong
fertilizer
12.7
2.79
1.67
4.87
Shanghai
Chemical
12.7
2.79
1.67
4.87
Harbei
fertilizer
12.7
2.79
1.67
4.87
Source: Data compiled from Zen (2006).
loss through the wall, (ii) they act as thermal storage to help ignition of fresh
feed, and (iii) they prevent the metal enclosure from corrosion.
The thickness of the refractory and insulation used is to be chosen with
care. For example, biomass ash melts at a lower temperature and is more
corrosive than most coal ash, so special care needs to be taken in designing
the gasifier vessel for biomass feedstock.
The construction of a side-fed gasifier is more complex than that of a
top-fed gasifier, as the reactor vessel is not entirely cylindrical and requires
numerous openings. The bottom opening is for the ash drain, the top opening
is for the product gas, and the side ports are for the feed. Additional open-
ings may also be required depending on the design. Because of the complex-
ity in the design of a pressure vessel operating at 30
70 bar and tempera-
tures exceeding 1000
C, any additional openings or added complexity in the
reactor configuration must be weighed carefully against perceived benefits
and manufacturing difficulties.
8.10 AUXILIARY ITEMS
The following subsections discuss the design of auxiliary systems in
fluidized-bed gasifiers.
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