Aviation Turbine fuel (ATF).ppt details has been given

atf BASICS AND DETAILS HS BEEN GIVEN

1. 1
Aviation Turbine fuel (ATF)

2. 2
Aviation Turbine fuel (ATF)
Shall consists of Blend of refined
hydrocarbon.
ATF are of 3 type ranging from low
flash point, Wide cut distillate
products to high flash point, narrow
cut , kerosene type material.

3. 3
Application
Aviation Gasoline for spark ignition
engine.
Kerosene type for turbine engine.
High flash for margin aviation.

4. 4
Composition of ATF ,
Characteristics.
Paraffin and Cyloparaffine
Chemically stable
Good storage stability under thermal
stress.
High calorific value.
Clean burning.

5. 5
Contd.
Aromatics
low heat content
Poor combustion
Higher solvent and swelling effect on
rubbers, sealants and insulators.
Poly nuclear aromatics burns with
illuminous flame.

6. 6
Contd.
Olefins
Chemically unstable, gum forming
tendencies.
Nearly clean burning
Intermediate specific gravity and
calorific value

7. 7
Typical hydrocarbon type
composition
Content % Weight I % Weight II
Paraffin 57 26
Naphthalene26 52
Aromatics 17 20
Olefin <1 2
Ultimate
Analysis
Hydrogen 14.1 13.3
Carbon 85.8 86.5

8. 8
IS Specification of ATF –Kerosene Type
Characteristics Requirement Method
Appearance Clear, Bright Visual
Colour Particulate, mg/l Report
Map 1.0
D 156
D 5452
Composition
a) Acidity mgKOH/g, max
b) Aromatics, % vol, max
c) Olefins, % vol, max
d) Sulphur, %wt, max
e) Sulphur Mercaptan, % mass,
max
OR
Doctor Test
0.015
22
5.0
0.30
0.003
Negative
P:113
P:23
P23
P34
P109
P19
Volatility
a) Distillation
10% vol, at °C, max
50% vol, at °C,
90% vol, at °C
FBP, C, max
Residue, % vol, max
Loss, % vol, max
b) Flash Point, °C max
c) Density, 15°C, kg/m
3
205
report
report
300
1.5
1.5
38
775-840
P:18
P;20 (Abel)
P:16
Fludity
a) Freezing Pt., C max
b) Kin. Vis at –20 C max
(-) 47
8.0
P:11
P:25

9. 9
Characteristics Requirement Method
Combustion
a) Specific Energy Mj/Kg, min
OR
Product of API grav. * Aniline Pt.
Min
b) Smoke Pt. mm, min
OR
Smoke Pt, mm, min
And
Naphthalene cont. % vol max
c) Hydrogen content, % by mass
42.8
4800
25
19
3.0
report
P:6
P:3
IP 57/95
P118
ASTM D 3701
Corrosion
a) Copper strip Corro. 2 hrs., 100
C, max
b) Silver Strip Corro. max
1
0/1 (refinery / delivery
(def), 1 (civ)
P:15
IP 227
Stability
Stability (JFTOT)
a) Filter Pressure Differential,
mmHg, max
b) Tube rating, Vis.
25
<3 No Peacock (P)
No Abnormal
P:97

10. 10
Characteristics Requirement Method
Contaminants
a)Existent Gum, mg/100, max
b)Water Reaction
i.Interface rating, max
ii.Separation rating, max
c)MSEP
(Without SDA)
With SDA
7
1b
Sharp separation
85
70
P:29
Steam jet
P:42
P:142
Conductivity
Electrical Cond.
ps/m (delivery Pt.)
50 min
450 max
IP 274/82
Lubricity
Wear scan dia, mm 0.88 max D 5001
To be reported
1.Refining components at the point of manufacture
2.Hydro processed components
3.Severely Hydro processed components

11. 11
Physico Chemical
Characteristics
Appearance
Product should be free from suspended
impurities and water.
May clog the filter.
May cause fuel pump failure.
May cause engine wear.
May cause corrosion.

12. 12
Acidity
Should be free from inorganic/ organic
acids.
Corrode storage tanks.
Transport containers
Aircraft tanks
Fuel delivery system.

13. 13
Suphur
Total sulphur limits as well as H2S and RHS
are limited due to their corrosiveness and
effects on elastomers.
Total Sulphur P:36
Mercaptance by doctor test.P:19
To a sample, sodium plum bide & small
amount of S is added. It is
shaked,decloration of sulphur floating at
the oil water interface is indicative of
positive test

14. 14
Copper Strip corrosion
Shows corrosiveness to copper and is
carried out at 100ºC for 2 hours.
Silver strip which is very sensitive
test to determine qualitative
corrosion of Sulphur is carried out.
4 hours @ 50ºC
16 hours @ 45ºC

15. 15
Silver Rating
No tarnish
Slight tarnish
Moderate tarnish
Slight Blacking
Total Black
This test mainly detects corrosive action
of H2S 0.5 ppm of H2S present in the
fuel is sufficient to cause Silver rating 4.
i.e. total black.

16. 16
Contd.
H2S may come in fuel during storage
and transportation by the presence
of Sulphate reducing bacteria known
as anerobic bacteria.

17. 17
Water Content in Traces
Water which can result in clogging is
undesirable even in ppm level and is
determined by Karl Fisher titration.
H2S and RHS interfere because of
oxidation by I2 in KF.
1 ppm sulphur as RHS causes error
of 0.2ppm water.

18. 18

19. 19
Water Seprometer Index
Water Separation ASTM D 3948
Test methods provides a measure of the
presence of surfactant.
Ability of fuel to release entrain are
emulsified water. (water fuel sample emulsion
is created using high speed mixture)
High seprometer index indicates good water
separation. (Water rejection tendencies are
measure by passing through coleaser. Water
rejection is observed by light transmission
measurement.)
Low value indicated poor water separation
which is caused by the presence of
surfactant. (Certain additives can also have
adverse effect on rating)

20. 20
Conductivity ASTM –D4865
Conductivity of aviation fuel are
generally low.
Can be increased by incorporating
static dissipater additives.
It acts quick dissipation of electrical
charge.
Conductivity of untreated fuel is
normally less than 10 Cu.

21. 21
Contd.
Properly treated fuel ranges between
50 and 450 Cu
(PISCO, Siemen/Meter known as
conductivity units)

22. 22
Static Electricity ASTM –D4865
Pumping, filtering and tank filling can
cause generation and accumulation
of electrostatic charge which can
result in spark causing fire and
explosive.

23. 23
Distillation
20% point control front end volatility
that fuel will readily vaporize from
cold starting and yet will not be too
volatile give rise to high evaporation
loss at high altitude.
90% point control the amount of
high boiling point material could
effect overall engine performance
Flash point is another volatility
criteria of safety.

24. 24
Freezing Point
Temperature encountered at high
altitude is very low
Temperature between 30000 to
80000 feet high is of the order of
-30ºC. The safe limit is -47ºC .

25. 25
Kinematics Viscosity
It is closely related to pump ability
over the temperature range and
consistency of nozzle spray pattern.
At low temperature increase in
viscosity causes poor pumpabitity at
higher altitude. Viscosity increases 5
to 6 times than at ambient ground
temperature.
Limits are fixed at -20ºC (Max 8 Cst)
and viscosity is to be reported at -
35ºC.

26. 26
Calorific Value
It is direct measure of fuel energy
content.
Heat energy is directly proportional
to useful work produced therefore
this is an important property for the
selection of fuel.
In the absence of the calorific value a
minimum value of product of Aniline
point and API gravity is also
applicable.
Correlation methods are available i.e.
ASTM –D4529, D3338, D1405.

27. 27
Contd.
Calorific value 10225 Cal/g(net)
minimum or product of API gravity
and aniline point 4800 min.

28. 28
Smoke point
Fuel with higher smoke point should have
lesser aromatics and poly aromatics and
thus should have better burning
characteristics.
Smoke point minimum 20mm.
Naphthalene Content
Luminous flame
Causes metal fatigue and increase in
engine deposits, limit maximum 3%wt &
luminometer number 45 min.

29. 29
Luminometer Number
Provides an indication of relative
radiation emitted by the combination
product of ATF.
Radiant heat transfer exert strong
influence on metal temp. of
combustion liners and hot section of
gas turbine.
Isooctane minimum
Tetralene maximum
Luminometer = 100 X ∆T Test Fuel -∆T
Tetralene
∆T Iso-
Octane -∆T Tetralene

30. 30
Existent Gum
It is a result of polymerization and
condensation of Olefins.
Large quantity of gum is indicative of
contamination of fuel by higher
boiling point.

31. 31
Thermal Oxidation Stability
(JFTOT)
On high speed the fuel is also used
as a heat sink for air conditioning
system and control of Cabin air
temperature.
Related to use of fuel as coolant in
supersonic flights.
At the speed 1500 mph the skin
temperature is 100ºC while at 2300
mph the skin temperature is 315ºC.
Continued exposure reduces the
strength of alloy.

32. 32
Contd.
Fuel should be thermally stable
under such condition and should not
produce varnish like materials
otherwise effect the efficiency of
heat exchanger

33. 33
Fuel effects on Turbine
performance
Poor Combustion
Low luminometer number.
Low smoke point
High aromatics
Heavier fuel contaminants

34. 34
Contd.
Excess Linear Blade deposit
High fuel viscosity
Low hydrogen content
High sulphur/ hetro atoms.
High aromatics
Soluble metals

35. 35
Contd.
Nozzle plugging/ wear
High particulate contamination.
Soluble metals.
Heavy end impurities
Poor thermal stability.
High sulphur content

36. 36
Fuel Effect On Turbine
Performance
Fuel control system malfunctions.
High sulphur
Heavy end contaminants.
Thermally reactive hydrocarbons
Low fuel viscosity
Poor lubricity

37. 37
Contd.
Filter Plugging.
Water contaminants
Surfactant contaminations.
Microbiological growth.
Improper freezing point.
Thermally reactive hydrocarbons.

38. 38