Autoignition
of
solid
fuels
driven
by
coupled
convective
and
radiative
heating
is
frequently
encountered
in
fires,
whereas
its
controlling
mechanism
rarely
revealed.
To
challenge
this
issue,
autoignition
tests
5
15
mm
thick
circular
wood
were
conducted
using
a
newly
developed
apparatus
enabling
heating.
The
total
heat
flux
imposed
on
was
maintained
at
25
kW/m2,
while
the
fractions
two
elements
changed
as
airflow
velocity
(uair)
temperature
(Tair)
varied
ranges
0-1.51
m/s
298-473.3
K.
Glowing
ignition
occurred
all
scenarios
except
for
one
case
due
to
enhanced
loss
declined
Flaming
observed
conditions
Tair=298
Four
stages
identified
during
flaming
combustion:
preheating
deformation
stage,
glowing
combustion
an
extinction
stage.
Compared
samples,
surface
rise
significantly
delayed
thermally
nature.
By
fitting
experimental
data,
new
formula
proposed
correlate
with
flux,
uair,
Tair.
Both
times
affected
complex
manner,
their
values
power
-0.5
approximately
linearly
depended
flux.
Damköhler
number
nondimensional
ratio
employed
quantitively
analyze
propensity.
Meanwhile,
ignitibility
map
identifying
non-flaming
regimes
derived.
ACS Omega,
Год журнала:
2024,
Номер
9(2), С. 2803 - 2814
Опубликована: Янв. 3, 2024
Compounded
aluminum
hydroxide
(ATH)
flame
retardants
have
been
widely
used
for
their
low
cost
and
environmentally
friendly
characteristics.
However,
previous
research
lacks
a
systematic
comprehensive
comparison.
In
addition,
the
combustion
characteristics
phase
characterization
of
asphalt
binders
are
not
taken
into
account
either.
this
work,
retardants,
instance,
APP,
Sb2O3,
ZB,
LDHs,
were
compounded
with
ATH.
The
retardant
behavior,
together
smoke
suppression
was
determined
by
LOI
CCT.
Furthermore,
mechanisms
on
investigated.
It
found
that
ATH
ZB
significantly
reduced
heat
release
suppressed
formation
toxic
volatiles
during
combustion.
This
because
ATH/ZB
facilitated
polyaromatic
structures
improved
resistance
char
layer.
APP
showed
an
antagonistic
effect
in
limiting
oxygen
test
reaction
between
inhibited
delayed
decomposition
more
phosphate
presenting
relatively
poor
barrier
properties
produced.
Fire Safety Journal,
Год журнала:
2023,
Номер
142, С. 104037 - 104037
Опубликована: Окт. 21, 2023
The
composition
of
a
fuel
and
the
combustion
environment
are
factors
that
impact
pyrolysis
processes.
natural
polymer,
timber,
synthetic
polymers,
polymethylmethacrylate
(PMMA)
polystyrene
(PS),
was
performed
at
constant
mass
loss
rate
(MLR)
using
feedback
control
loop
utilising
Fire
Propagation
Apparatus
(FPA)
under
inert
oxidative
environments.
controlled
MLR
(2
g
s−1
m−2)
enabled
representative
means
monitoring
emissions
via
combination
spectroscopic
techniques.
Reported
yields
were
calculated
adapted
Fourier-transform
infrared
spectroscopy
(FT-IR)
data
based
upon
species
detected
gas
chromatography-mass
spectrometry
(GC-MS).
speciation
offered
by
GC-MS
used
to
adjust
recorded
FT-IR
yields,
facilitating
an
insight
into
emissions.
presence
molecular
oxygen
not
found
drastically
influence
decomposition
behaviours
investigated
polymers
with
primary
monomers
being
relatively
unaffected
atmospheric
environment.
However,
difference
noted
when
as
generated
char
visually
different
atmospheres.
oxidation
confirmed
lower
applied
heat
flux
required
sustain
desired
rate.
We
conclude
proposed
combined
analytical
approach
shows
great
potential
for
tracking
quantifying
effluent
Case Studies in Thermal Engineering,
Год журнала:
2023,
Номер
51, С. 103523 - 103523
Опубликована: Сен. 23, 2023
The
ignition
of
the
building
insulation
materials
by
a
hot
particle
is
typical
spot
fire
phenomenon,
but
scientific
understanding
still
limited.
In
this
work,
steel
spherical
(6-16
mm
and
800-1200
°C)
was
dropped
onto
low-density
expandable
polystyrene
(EPS)
foam
with
an
external
airflow
velocity
0-6
m/s
to
obtain
limit
at
flash
point
point.
Airflow
provides
alternative
shortcut
transition
unstable
flame
strong
fuel
burnout,
because
increases
oxygen
supply
heating
rather
than
cooling
particle.
As
increases,
both
points
first
become
easier
reach
facilitates
mixing
pyrolysates
in
Smothering
Regime.
When
Thermal
Regime,
delay
time
remains
stable.
Further
increasing
Chemical
slightly
until
blows
off
or
blowing
away
flammable
mixture
from
surface.
Such
competitive
effect
on
also
qualitatively
verified
theoretical
analysis.
Flame
retardants
inside
EPS
do
not
change
inhibit
even
under
assistance
airflow.
This
work
enhances
comprehension
complex
interactions
between
spotting
hot-particle
facades.
