A-Type :
A-type watertube
boilers represent an alternate way designing
watertube boilers. It is symmetrical,
well balanced boiler with a large furnace
volume.
The A-type design such as Thermoboil
A-type boiler provides a larger furnace
than an O-type design for example and
will offer the same advantages than
the O-type as far as symmetry and natural
circulation are concerned. It will go
as high in capacity, pressure and temperature
than an O-type but will be bigger and
cost more money since it is bigger and
has an extra mud drum. Capacities for
package units can go as high as 250,000
lbs/hr (115 tons/hr) with pressures
up to 1500psig (103 bar) and temperatures
up to 1000F (537C).Higher capacities
are possible with field erected units.
It is very appropriate to fire no.6
oil, no.2 oil or gas .It is also available
with an open bottom furnace to allow
burning of solid fuels such as wood
residues, agricultural wastes, bagasse
etc. A D-type or an O-type boiler is
not as suitable for solid fuel burning
due to its geometry.
Radiant and convective type superheaters
can be added at the rear end of the
A-type Thermoboil units and provide
superheated steam at a constant temperature
over all the firing range. For very
large capacities, high pressures and
temperatures, it is often the choice
of the consulting engineers and of the
end users. The design can be built with
membrane waterwalls or with tangent
tubes. In most cases membrane waterwalls
are preferred.
It can perform as well as a D-type but
will cost a little bit more to produce.
A-type boilers are often using for cogeneration,
petrochemical industries, industrial
processes etc. It is a rugged and conservative
design. On large sizes the furnace gas
pressures are much lower than a D-type
or an O-type due to the boiler bank
configurations and the burners will
require less fan power.
It is a well balanced boiler design.
It will be easier to ship by road or
by train than
D-types because of its A-type shape,
which fits better with tunnels and bridges.
Capacities:From
20,000 lbs/hr (10 tons/hr) to
250,000 lbs/hr (115 tons/hr) with
or without superheater
Pressures:250
psig (17 bars) design up to 1500 psig
(100 bars)
Superheaters:
Temperature up
to 950 F (510 C)
Fuels:Oil,
gas or combination, or solid fuels
-Membrane or
tangent tube wall construction to ASME
code section I
-Optional water cooled membrane rear
wall
-Optional water cooled membrane front
wall and burner throat
-Open bottom furnace available for solid
fuel firing
-Steam purity up to 1 ppm
Phisical Data "A" Type Boilers:
Boiler
model number |
Capacity
tons/hr |
-A-
Length
mm |
-B-
Width
mm |
-C-
Height
mm |
-D-
Base width
mm |
-E- |
-F- |
Gas outlet mm |
Width |
Length |
|
Weights
(In
kg) |
Dry |
Flooded |
|
A1-20 |
9.0 |
4500 |
3685 |
3810 |
2615 |
2135 |
610 |
29500 |
36500 |
A1-30 |
13.5 |
5410 |
3685 |
3810 |
2615 |
2135 |
610 |
31500 |
41000 |
A1-40 |
18.0 |
6100 |
3685 |
3810 |
2615 |
2135 |
610 |
34000 |
45500 |
A1-50 |
22.5 |
6830 |
3685 |
3810 |
2615 |
2135 |
610 |
38500 |
50000 |
A2-60 |
27.0 |
7035 |
3785 |
4215 |
2870 |
2385 |
810 |
43000 |
59000 |
A2-70 |
32.0 |
7550 |
3785 |
4215 |
2870 |
2385 |
810 |
45500 |
61000 |
A2-80 |
36.5 |
7925 |
3785 |
4215 |
2870 |
2385 |
810 |
47500 |
66000 |
A2-90 |
41.0 |
8460 |
3785 |
4215 |
2870 |
2385 |
915 |
50000 |
68000 |
A3-100 |
45.5 |
10060 |
3885 |
4725 |
2870 |
2385 |
1220 |
59000 |
79500 |
A3-110 |
50.0 |
10600 |
3885 |
4725 |
2870 |
2385 |
1220 |
61500 |
82000 |
A3-125 |
57.0 |
11500 |
3885 |
4725 |
2870 |
2385 |
1320 |
66000 |
88500 |
A3-150 |
68.0 |
12500 |
3885 |
4725 |
2870 |
2385 |
1320 |
68000 |
95000 |
A4-175 |
79.5 |
12930 |
3935 |
5080 |
2920 |
2385 |
1830 |
75000 |
109000 |
A4-200 |
91.0 |
13550 |
3935 |
5080 |
2920 |
2385 |
1830 |
79500 |
113500 |
A4-250 |
113.5 |
15170 |
3935 |
5080 |
2920 |
2385 |
1830 |
86000 |
125000 |
*All dimensions
are metric