Equipos para calentamiento de crudo

1. BY
GAURAV KANODIA

2. A heater is a heat transfer equipment where
heat of combustion of fuel oil/fuel gas is used
to increase the temperature of the desired
fluid.

3.  On the basis of Draft ( Natural, Forced, Induced
and Balanced Draft)
 On the basis of Structural Configuration (
Cylindrical, Cabin, Multi cell)
 On the basis of Radiant Tube Configuration (
Vertical, Horizontal, Helical and Wicket Type)
 On the Basis of Burner position ( Up fired, Down
fired and Wall fired)

5. Balanced Draft, Twin Cell, Cabin Type,
Horizontal Radiant Tubes and Up fired.

6.  API 560 : Fired Heater for Refinery
 API 530 : Heater Tube thickness in Refinery
 API RP 550 : Installation of Instruments and
Control System for Fired heater and Steam
Generation
 EA 7301 : Guidelines for Noise

7. Heat Distribution in Radiant Section
1. Flame Radiation 17%
2. Hot Gas Radiation (Combustion Products) 32%
3. Convection from Flue Gases 7%
4. Refractory Reflection 14%
Mirror Effects
Total 70%
Convection Section 15%
Losses 15%

8. CDU Heater
 Heat Duty : 43.84 MillionKcal/hr.
 Fluid Handled : Crude@18000MT/D.
 Inlet Crude Temp. : 310 C
 Outlet Crude Temp. : 365 C
 Fuel Used : Fuel Gas/Fuel Oil/
Hot well gases

9.  Crude
IN OUT
Liquid (Kg/hr) 750000 420553
HC Vapour (Kg/hr) 329447
Operating pressure 19.73 3.73
(kg/cm2 g)
Operating temperature 310 365
(Deg.C)

10.  MP Steam
IN OUT
Flow (kg/hr) 13150 13150
Pressure(Kg/cm2 g) 15.5 14.5
Temperature (Deg. C) 209 315

11.  Topmost part of the Convective Section
100 mm thick Castable type
 Entrance of the Convective Section
100 mm thick Castable type+50 mm
thick C.Fibre board with 8mm dia
SS316L lugs+0.1mm thick SS316 foil
between Castable and board

12.  Arch Section
125 mm thick C.Fibre module+25mm
C.Fibre blanket with SS 316L studs+0.1 mm
SS316 foil between blanket and fibre
module.
 Radiant Section
100 mm thick C.Fibre module +25mm
C.Fibre blanket with SS316L studs+0.1 mm
SS316 foil between blanket and C.Fibre
module

14. No. of Passes : 8
No. of Tubes in Convective Section : 96
No. of tubes in radiant Section : 128
MOC of Tubes : 5Cr,0.5Mo
O.D. of Tubes : 168.3 mm
Thickness of tubes : 7.11 mm
I.D. of Tubes : 154.08 mm

15. It is the negative air pressure generated by
the buoyancy of hot gases generated inside
the furnace.
Measured At :
1. Firebox Floor
2. Below the Convective Section
3. At the Duct Inlet

17.  Fuel Gas (mol %)
Hydrogen 48.72 N Butane 2.33
H2S 0.015 C5+ 1.84
CO2 0.08 NH3 0.01
Water 0.55
CH4 27.10
C2H6 13.86
C2H4 1.03
C3H8 3.48
C3H6 0.29
i-Butane 0.68
Butenes 0.01

18. Pressure at burner (Kg/cm2 g) 1.5
Temperature at burner (Deg.C) 40
Heating value (Kcal/kg) 11590
 Ejector off gas from VDU
Flow (kg/hr) 2590
Pressure(Kg/cm2 a) 1.1
Temperature (Deg.C) 45

19.  Fuel Oil
Sulphur Content 1%( wt.)
Nitrogen 834 ( wt ppm)
Ni <1 wt ppm
V <1 wt ppm
Na 1 wt ppm
Pressure at burner (Kg/cm2 g) 5.5
Temperature at burner (Deg.C) 50-70
Viscosity 20cSt
Heating value (Kcal/kg) 9500
Atomizing Steam Pressure 7.5
at burner (Kg/cm2 g)

20. FLUE GAS COMPOSITION
(Mole %)
CO2 11.2
O2 3.28
N2 74.3
H2O 11.17
SO2 0.05

21. It is a device which positions a flame in the
desired location by delivering fuel and air
with sufficient mixing energy to ensure
continuous ignition and complete
combustion.

22.  Combustion Air Control
Air Flow Rate to the Heater
Oxygen Percentage in the Flue gases
 Fuel Oil/ Fuel Gas Control
Outlet Temp of Crude
 Draft Control
Suction of the I.D. Fan
 Crude Pass Control
Pass Balancer

24. Visual Observations of Combustion
1. Colour of flame
2. Flame Impingement
3. Flame Shape and Stability
4. Burner Air Register Setting
5. Fuel Pressure
6. Draft

25. Visual Observation of Firebox
1. Colour of Refractory and tube support
2. Appearance of tube
3. Appearance of refractory
4. Infrared Scan
5. Smoke from Stack
6. Flame Type

29.  Includes all oxides of Nitrogen except N2O
Hazards of NOx
 Acid Rain
 Smog

31. 1. Thermal Nox
2. Prompt Nox
3. Fuel Nox

32.  Formation at High Temperature ( > 1000 C)
N2 + O = NO + N
N + O2 = NO + O
N2 + O2 = 2 NO
 d[NO]/dt = A e(-Ea/RT) [N2] √[O2]

33. Relatively Low Temperature conditions
 Important under Fuel Rich conditions
 Relatively fast reaction between HC, O2 and N2
Formed mostly at flame base during earliest
stage of combustion
CH4 +O2 +N2 NO + NO2 + CO + H2O
+ trace particles
CH4 +N2 HCN CN
CN + O2 NO + CO + H

34.  Direct Oxidation of organo nitrogenous
compounds present in fuel
N + O2 NO + NO2 + CO2 +
H2O + trace species

35.  Pretreatment
 Combustion Modification
 Post Treatment

36.  Fuel Switching or Treatment
 Using Additives
 Oxidiser Switching

37.  Excess Air
 Low NOx Burners

38.  Premix gas Burners
 Nozzle gas Burners
 Fuel oil Burners
 Combination of F.O. and F.G. Burners
 Low NOX Burners

39.  Air Staging
 Fuel Staging
 Internal Furnace Gas Recirculation
 Water or Steam Injection
 Ultra Lean Premixing
 External Flue Gas Recirculation

42. Advantages
 High Intensity flame (Compact Flame)
 Large Fuel – Gas Orifice
 Low top plugging in case of unsaturated HC
in feed
Disadvantages
 Limited Turndown
 Flashback
 Limited use with different fuels
 Limited Forced Draft application

43. Advantages
 High Turndown Ratio
 No Flashback
 Wide variety of fuels used
Disadvantages
 Tip Fouling due to small ports
 Less Efficient mixing with air

53. Sr.
No.
Actuated By Action Need
1
2
Low Low flow
from P-102
Low Low flow
pass through
any of the 8
passes
Close
•Main FG to F101 (SDV)
•FO to F101 (SDV)
•FO return from F101 (SDV)
•Offgas ex V120 to V133
(SDV)
•Offgas ex V132 to V133
(SDV)
•Main FG to F101 (PV)
Open
•FG vent of F101 (SDV)
•Offgas ex V120 to V121
(SDV)
•V132 offgas KOD vent (SDV)
•F101 Stack damper
•FD fans
•ID fans will trip
• To cut off all the fuels to
the furnace.
•To remove any
combustible matter, if any
in the firebox along with
the flue gases.

54. Sr.
No.
Actuated By Action Need
3. Low Low fuel
gas pressure to
F101
Close
•Main FG to F101 (SDV)
•Main FG to F101 (PV)
Open
•FG vent of F101 (SDV)
Low gas pressure will
cause flame supported
by gas to extinguish,
thus causing build up of
combustible matter in
the firebox.
4. Low Low Fuel
Oil pressure to
F101
Close
•FO to F101 (SDV)
•FO return from F101
(SDV)
Low oil pressure will
cause flame supported
by it to extinguish, thus
causing build up of
combustible matter in
the firebox.

55. Sr.
No.
Actuated By Action Need
5. Emergency shut
down switch for
F 101 operated
from Control
Room or field
Close
•Main FG to F101 (SDV)
•Pilot FG to F101
•FO to F101 (SDV)
•FO return from F101 (SDV)
•Offgas ex V120 to
V133(SDV)
•Offgas ex V132 to
V133(SDV)
•Main FG to F101 (PV)
•RSDV 133A
Open
•FG vent of F101 (SDV)
•Offgas ex V120 to
V121(SDV)
•V132 offgas KOD vent (SDV)
•F101 Stack damper
•FD fans
•ID fans will trip
In case of emergency,
all the fuel supply
connections are to to
isolated including the
pilot gas.

56. Sr.
No.
Actuated By Action Need
6 One FD fan trip,
as sensed by:-
•Low speed of
either of the FD
fans
•Motor Contact
of either of the
FD fans
Close
• Discharge damper of the
tripped fan will close
automatically in 10 seconds
and it’s motor will stop.
•Open
•Inlet damper of running fan
will open fully and
combustion action will shift
to VFD mode automatically.
•When VFD is set manually
and air flow is being
controlled by inlet box
damper, in case of
overloading of inlet box
damper, combustion control
action will shift to VFD mode
automatically.
Isolate the tripped FD
fan and take the full
load on the other
running fan.

57. Sr.
No.
Actuated By Action Need
8 Failure of both
FD fans, as
sensed by:-
•Combustion Air
flow low low
•Low speed of
RST 394/398
Close
•Main FG to F101 (SDV)
•FO to F101 (SDV)
•FO return from F101 (SDV)
•Offgas ex V120 to
V133(SDV)
•Offgas ex V132 to
V133(SDV)
•Main FG to F101 (PV)
Open
•FG vent of F101 (SDV)
•Offgas ex V120 to
V121(SDV)
•V132 offgas KOD vent (SDV)
• Pilot gas will remain online
Isolation of the
heater as no air for
combustion will be
supplied.

58. Sr.
No.
Actuated By Action Need
9 Failure of ID
fans, as sensed
by:-
•Low Speed
setting
•Motor Contact
Open
Stack Damper
If Stack Damper fails to open
within 20 sec., then
Close
•Main FG to F101 (SDV)
•FO to F101 (SDV)
•FO return from F101 (SDV)
•Offgas ex V120 to
V133(SDV)
•Offgas ex V132 to
V133(SDV)
•Main FG to F101 (PV)
Open
•Stack Damper will open
automatically within 20 sec.
•FG vent of F101 (SDV)
•Offgas ex V120 to
V121(SDV)
•V132 offgas KOD vent (SDV)
• FD fans will trip
Isolation of the
heater is required, if
stack damper doesn't
opens, as it can lead
to pressure build up
in the heater.

59. Sr.
No.
Actuated By Action Need
10 High High Arch
pressure of F
101 (2 out of 3
logic)
Close
•Main FG to F101 (SDV)
•FO to F101 (SDV)
•FO return from F101 (SDV)
•Offgas ex V120 to
V133(SDV)
•Offgas ex V132 to
V133(SDV)
•Main FG to F101 (PV)
Open
•Stack Damper will open
•FG vent of F101 (SDV)
•Offgas ex V120 to
V121(SDV)
•V132 offgas KOD vent (SDV)
• FD fans will trip
Indicates the failure
of ID fan or signal
failure to Stack
damper. So the need
for isolation arises.

60. Sr.
No.
Actuated By Action Need
11 Actuation of the
following
together:-
•FG to F101 trip
•Vap Naptha to F
101 trip
•FO to F101 trip
Open
•Stack Damper will open
•FD fans will trip
•ID fan will trip after 5
mins.
Isolation of the heater
is necessary if fuel
fails.
12 Stack damper
cannot be closed
unless ID fan is
running
If the Stack damper
closes with the ID fan
out of service,
pressure will build up
in the furnace and can
be hazardous.
13 F 101 CAPH flue
gas outlet temp
High High (2 out
of 3 logic)
Open
•Stack damper will be
opened
•ID fan will trip

61. Need
To Blast off the impinged combustion particles
off the tubes with sufficient energy
Time
When the flue gas temperature from outlet of
convection section is sufficiently high / When
crude temp. from the outlet of convection section
is relatively low.
Soot
It is sticky, consists of high mol. wt. polycyclic
HC.

62.  Rotating element Soot Blower
 Retractable Lance Soot Blower
 Two Rows of soot blowers
 Each row of soot blower covers 3 +3 tube rows
 3 minute Cycle

64. PROCEDURE
 Bypass I-103 ( ID Fan Failure), I-106 ( Stack
Damper bypass)
 Open the Stack Damper
 Shut off the ID fan
 Increase the fuel pressure to accommodate the
low combustion air temperature

65.  Field Operator will first drain the steam line
before starting the soot blowing activity.
 Open the main steam valve to soot blower
header
 Start the soot blowing cycle
 Observe the stack to gauge the extent of soot
blowing
 Continuously monitor the field panel during
the operation

66.  After the soot blowing cycle has been
completed, physically verify the blower
assembly
 When the stack outlet is sufficiently clear,
take the ID fan online and close the stack
damper.
 Adjust the fuel and draft accordingly.

67.  Purging and Testing of Fuel Lines
 Establish fluid flow and purge firebox
 Light the Pilot Burner
 Light Fuel Gas and Fuel Oil
 Raise HOT

68.  Manual Control
 Decrease Firebox Temperature
 Bypass APH
 Pilots on until main FO/FG system purged
 Depressurize the Offgas and Main FG lines
 N2 purging

69.  Thermal Efficiency = Heat tr. to process fluid
Net Heat Released
 Radiant Section Efficiency
Radiant Flux rate
Bridge wall Temperature

70.  Direct Method
 Indirect Method
ƞ direct = Heat Transferred to crude
Total Heat Input
Ƞ indirect = 1- Heat Loss
Total Heat Input

72. Total Heat Input = Hair+ HFO +HFG + HSteam +
MFO×Cv,FO + MFG×Cv,FG
Direct Method
Heat Transferred
to Crude = M Cp(T2-T1)
= Mliq2{Cp,liq2(T2-Ta)}
+Mvap2{Cp,vap2(T2-Ta)}
-Mliq1{Cp,liq1(T1-Ta)}

73. Indirect Method
Losses
 Setting Losses
o Radiant Zone Losses
o Convection Zone Losses
 Stack Losses
Stack Losses = Mflue {Cp,flue(Tstack-Ta)}
Mflue = Mair + MFO +MFG +Msteam
Mair = Mair,FO + Mair,FG

74. Mair,FO = MFO ×(x+y/4)(1+α)×138.095
(12x+2y)
where the formula for FO is CxHy.
Mair,FG = MFG×(a+b/4)(1+α)×138.095
(12a+2b)
where the formula for FG is CaHb.
Where α is % excess air.

75. 1 kg C requires 11.51(1+x) kg air
1 kg H requires 34.52(1+x) kg air
where x = % excess O2
If C/H = y, S content in fuel = 1%
C in fuel burnt = y*m*0.99/(y+1) kg
H in fuel burnt = m*0.99/(y+1) kg
Where m = kg of fuel burnt

76. Radiant Zone Losses
= F×σ×Afirebox (T4
firebox –T4
amb)
Convection Section Losses
= h Aconvection (Tconvection – Tamb)
h = (1 + 0.225 * V)
where V = wind velocity (ft/sec)

77.  O2, Steam, Air Qnty., Insulation, Stack Temp.,
Air Ingress, Air Inlet Temp., Area of Heat
Transfer on process side ( soot removal,
geometry), Area of heat transfer on flue gas
side

78.  Use of APH
 Finned Tubes / Studded Tubes
 O2 Analyzer & CO Analyzer
 Glass Window Peep Hole
 Twist Caps/ Covers
 Vertical Furnace instead of Box
 Refractory Coating
 Soot Blowers

79.  Proper Burner Alignment
 Steam Atomization
 Additional Coils Installation

80. TROUBLE CAUSES &
Effects
SOLUTION
Pulsating Flame Lack of O2, Refractory
breakdown,
Increase Air
Flame Impingement
on Tubes
Overfiring, Lack of
O2,Tube colour, coke
formation, high firing
Check excess O2 levels,
Steam Atomization
Pressure, Oil tip check for
erosion and regular
cleaning,
Oil Spillage Poor Steam Atomization,
Low temp. of Oil, Erosion
of burner and atomizer
tip, Improper placement
of oil gun, coke
formation on burner tile
Check temp. of oil,
atomizing steam,
placement of oil gun, oil
gun position.

81. TROUBLE CAUSES &
Effects
SOLUTION
High Stack
Temperature
After burning in
convection section,
Lower efficiency of
heater, Loss of air in
firebox
Check air leaks, Increase
Air, soot blowing,
Overheating of
Convection Section
Failure of Shock tubes,
High TI and PI indication
at Convection Section
Inlet,
Open Stack Damper if high
arch pressure, Check
excess air,
Motor Boating when
firing FO
Light Oil firing, Low
pressure of oil, Low
Flash Point of oil,
Pulsating Flame, Noise
Check FO and atomizing
steam pressure, Steam leak
in oil, water in the oil,