P a r r I n s t r u m e n t C o m p a n y
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Parr Fixed Bomb & Bucket Technology
I
n the fixed bomb and
bucket design
used in the 6400
Automatic Isoperibol Calorimeter,
the bomb and bucket are not
removed from the calorimeter dur-
ing routine operations. This design
concept has made it possible to
offer unique levels of automation for
the entire calorimetric determina-
tion, not just the data collection and
reporting steps. The result of this
automation will save approximately
five minutes of operator time per
test when compared to any remov-
able bomb calorimeter.
Oxygen Charging and Release
The fixed bomb and bucket design
allow the oxygen supply to be direct-
ed into the head of the bomb at the
beginning of each test. The head of
these bombs incorporate a check
valve which dynamically seals when
the bomb is pressurized. At the end
of the test, the gases in the bomb
are automatically released while the
calorimeter is being returned to its
starting temperature.
Fixed Bucket
The bucket in these calorimeters has
been designed to provide smooth
circulation over the surface of the
vessel. The design also repeatedly
fills the bucket volumetrically.
The bomb head closure seals the
bucket at the same time the bomb is
closed. This unique design mini-
mizes the amount of water required
for the test as well as permitting
rapid, automatic and repeatable fill-
ing for each test. The water heated
by the combustion is automatically
drained from the bucket at the con-
clusion of the test and replaced
with cooling water to bring the
bomb and bucket rapidly back
down to the starting temperature
for the next test.
Fixed Bomb
The 6400 Calorimeter features the
patented closure design of the Parr
Fixed bombs. This design allows the
user to seal and lock the head into
the cylinder with a simple 1/16th
turn. The main bomb seal is an
O-ring optimized to minimize fric-
tional wear, improving the lifetime
of this seal.
At the conclusion of the test,
the inside surface of the bomb is
washed to remove the byproducts
of the combustion from the bomb.
The automation of the bomb wash-
ing step eliminates one of the most
tedious and time-consuming manual
operations required with removable
bomb calorimeters. Besides the elim-
ination of the drudgery of manually
washing the bomb, a not so obvious
advantage of the fixed bomb design
is that the bomb is always washed
as soon as the final temperature
can be determined. Generally, this
is within 4-5 minutes of the time the
bomb is fired. This holds to an abso-
lute minimum the time any acids
produced by the combustion can
attach to the inner surfaces of the
bomb. This has improved the service
life of these bombs in comparison to
removable bombs.
1138 Oxygen Bomb
The 1138 is a 250 mL bomb with a
sample range up to 8000 calories
per charge. The
straight wall
design of this
bomb improves
bomb rinse
recovery, bet-
ter precision
and faster test
times.
1136 Oxygen Bomb
The 1136 Oxygen Bomb, like the
standard 1108 Oxygen Bomb, is 350
mL in internal volume. It will safely
handle samples
liberating up to
a maximum of
8000 calories
per charge.
Both the
1136 and the
1138 oxygen
bombs use
the A1450DD
head assembly,
therefore service parts in the 6038
kit are interchangeable on these
models. Older model 1136 and 1138
bombs with the head assembly
model number A895DD will use
spare parts kit 6036.
Please see page 21 for Maintenance
Kit Selection Guide.
100 Years of Leadership and Innovation
1980
Parr introduced
dynamic operating
mode and isoperibol
calorimetry to dra-
matically shorten
calorimetric tests.
1979
Parr introduced the
first microprocessor-
based controller for
handling all steps in
a calorimetric test.
1962
Parr introduced the
first automatic jacket
temperature control
system for an adia-
batic calorimeter.
1933
Parr introduced the
first self-sealing
oxygen combustion
bomb.
1916
Parr introduced its
first water-jacketed,
adiabatic calorim-
eter using hot water
injection for temp-
erature control.
1911
Parr introduced an
oxygen bomb calo-
rimeter of a new
design with a bomb
made of an acid-
resistant alloy.
1899
Professor S.W. Parr
developed a simpli-
fied calorimeter for
measuring the heat-
ing value of coal.
