12
Parr Instrument
Oxygen Combustion Bombs
Bulletin 4700
For Reliable Combustion
Procedures
C
ombustion with oxygen in a sealed Parr bomb has been
accepted for many years as a standard method for
converting solid and liquid combustible samples into
soluble forms for chemical analysis. It is a reliable method whose
effectiveness stems from its ability to treat samples quickly and
conveniently within a closed system without losing any of the
sample or its combustion products. All hydrocarbons are oxidized
to carbon dioxide and water by the reaction, and all sulfur
compounds are converted to soluble forms and absorbed in a
small amount of water placed in the bomb. Organic chlorine
compounds are converted to HCl or chlorides. Any mineral
constituents remain as ash, but other inorganic elements such as
arsenic, boron and all of the halogens are recovered with the bomb
washings. The entire procedure is simple and straightforward, with
its superiority over other sample preparation methods derived
primarily from it’s:
speed, safety and significant sample size.
Samples large enough to be statistically significant can be treated
in these bombs with complete sample recovery.
Many applications.
The reliability of the oxygen bomb
method has led to its acceptance as the basic procedure for deter-
mining sulfur, halogens, and other elements in a broad range of
combustible materials, particularly:
Sulfur
in coal, coke and refuse derived fuels.
Sulfur
in petroleum products.
Chlorine
in petroleum and other combustible samples.
Other halogens and elements such as: arsenic, mercury,
phosphorus and boron can also be determined by oxygen bomb
methods. Heavy metals present as trace elements in combustible
samples can be determined by adding a quartz liner described on
page 13. A full discussion of oxygen bomb methods, including a
listing of standard ASTM, ANSI, API, IP test procedures and an
extensive bibliography is provided in Parr Manual 207M.
Copies are available on request at no charge.
The 1108 Oxygen Bomb
T
his is the standard, 342 mL, general purpose bomb which
is widely used in Parr oxygen bomb calorimeters and
combustion apparatus. It will safely burn samples (usually
weighing about one gram) which liberate up to a maximum of
8000 calories per charge using oxygen-charging pressures up to
40 atm. All designs used in the 1108 bomb have been developed
specifically to give the user a reliable bomb that is easy to
handle, easy to maintain and safe for its intended use. Separate
valves are provided for charging the bomb with oxygen and for
releasing gases at the end of a test. Oxygen is admitted through a
check valve. Gases are released through a needle valve. Deflector
nuts on the inlet and outlet passages divert the incoming gas and
protect the valves from the combustion flame. Both valves can
be replaced. The firing circuit is completed through a grounded
electrode which also supports the combustion capsule. An
insulated electrode with ceramic flame protection carries the
firing current to the fuse wire.
The standard 1108 bomb is made of a special columbium-
stabilized stainless steel selected for its excellent resistance to the
mixed nitric and sulfuric acids produced in a bomb combustion.
This is a superior alloy which is suitable for most combustion
tests, yet neither it nor any other stainless steel will resist the
corrosive atmosphere produced when burning samples
containing halogen compounds. For these applications Parr
offers the 1108CL bomb described below.
A Chlorine-Resistant Bomb
P
arr now offers a new 1108CL bomb which is the same as the
1108 model, but with a head and cylinder made of an alloy
with superior corrosion resistance to the free chlorine and
halogen acids released when burning chlorinated samples. Users
who intend to test waste materials and combustible solvents are
urged to select the 1108CL bomb instead of the 1108 for its longer
service life under extreme corrosive conditions. Bomb mainte-
nance is also improved. In most cases 1108CL bombs returned to
the factory for scheduled maintenance can be restored to optimum
finish simply by repolishing instead of having to rebore the
cylinder to remove pits. The 1108CL bomb may be purchased
separately or it can be substituted for the standard 1108 bomb in
any Parr calorimeter or combustion apparatus.
An oxygen filling system and other accessories for the 1108
bombs can be ordered from listings on page 15, or a bomb
complete with all necessary accessories can be obtained by
ordering the 1901 oxygen bomb apparatus described on page 13.
ORDERING INFORMATION
1108
Oxygen combustion bomb
342 mL, Carp. 20Cb-3 stainless steel
1108CL
Oxygen combustion bomb, 342 mL,
for chlorine service.
Parr
Oxygen
Combustion Bomb
