The document compares changes made between editions of API 560 standards regarding specifications for fired heaters and burners. Some key changes include: the 4th and 5th editions specify that burner design ensure complete combustion and limit flame length; minimum burner clearances have been updated and specifications added for ultra low NOx burners; and material requirements have been specified for components operating in high H2S environments. Furnace Improvements Services is an engineering company that provides design and consulting services for fired heaters and boilers, including CFD modeling, revamps, and new installations.
1. Introduction reasons for purification, types of poisons, and typical systems
2. Hydrogenation
3. Dechlorination
4. Sulfur Removal
5. Purification system start-up and shut-down
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
(HTS) High Temperature Shift Catalyst (VSG-F101) - Comprehensiev OverviewGerard B. Hawkins
The high temperature shift duty introduction and theory
HTS catalyst characteristics
developments over time
Typical HTS operational problems
Improved catalysts
VULCAN Series VSG-F101 Series
Summary
Reformer Tube design principles
- Larsen Miller Plot
- Larsen Miller & Tube Design
- Design Margins - Stress Data Used
- Max Allowable & Design Temperature
- Tube Life
- Effect of Temperature on Life
- Material Types
HK40: 25 Cr / 20 Ni
HP Modified: 25 Cr / 35 Ni + Nb
Microalloy: 25 Cr / 35 Ni + Nb + Ti
- Alloy Developments
- Comparison of Alloys
Manufacturing Technology
- Welds
Failure mechanisms
- Failure Mechanisms - Creep
- Creep Propagation
- Common Failure Modes
- Uncommon Failure Modes
- Failure by Creep
- Creep Rupture - Cross Section
- Failure at Weld
Actions to Take if Tube Fails
- Pigtail Nipping
Inspection techniques
Classification of Problems
- Visual Examination
- Girth Measurement
- Ultrasonic Attenuation
- Radiography
Eddy Current Measurement
LOTIS Tube Inspection
LOTIS Compared to External Inspection
Common poisons include
Sulfur
Chlorides and other halides
Metals including arsenic, vanadium, mercury, alkali metals (including potassium)
Phosphates
Organo-metalics
1. Introduction reasons for purification, types of poisons, and typical systems
2. Hydrogenation
3. Dechlorination
4. Sulfur Removal
5. Purification system start-up and shut-down
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
(HTS) High Temperature Shift Catalyst (VSG-F101) - Comprehensiev OverviewGerard B. Hawkins
The high temperature shift duty introduction and theory
HTS catalyst characteristics
developments over time
Typical HTS operational problems
Improved catalysts
VULCAN Series VSG-F101 Series
Summary
Reformer Tube design principles
- Larsen Miller Plot
- Larsen Miller & Tube Design
- Design Margins - Stress Data Used
- Max Allowable & Design Temperature
- Tube Life
- Effect of Temperature on Life
- Material Types
HK40: 25 Cr / 20 Ni
HP Modified: 25 Cr / 35 Ni + Nb
Microalloy: 25 Cr / 35 Ni + Nb + Ti
- Alloy Developments
- Comparison of Alloys
Manufacturing Technology
- Welds
Failure mechanisms
- Failure Mechanisms - Creep
- Creep Propagation
- Common Failure Modes
- Uncommon Failure Modes
- Failure by Creep
- Creep Rupture - Cross Section
- Failure at Weld
Actions to Take if Tube Fails
- Pigtail Nipping
Inspection techniques
Classification of Problems
- Visual Examination
- Girth Measurement
- Ultrasonic Attenuation
- Radiography
Eddy Current Measurement
LOTIS Tube Inspection
LOTIS Compared to External Inspection
Common poisons include
Sulfur
Chlorides and other halides
Metals including arsenic, vanadium, mercury, alkali metals (including potassium)
Phosphates
Organo-metalics
Fired heaters are used for heating hydrocarbons fluids in the refineries and petrochemical plants. They are used for high temperature heat transfer. In most fired heaters, we are burning fuel gas as source of heat . There are many heaters in the world where liquid fuel is also burnt in the fired heaters to provide the energy, but their number is decreasing due to tighter pollution laws. Heaters that are processing hydrocarbons services are prone to coking and cracking depending upon the nature of the hydrocarbons being processed. Typically heaters may run length of anywhere from 3 months for coking service to 6 years for different services. Heater designers and operators are always faced with the challenge of providing uniform heat transfer to all the tubes. Engineers use equations that assume uniform heat transfer to heater tubes When designing fired heaters. However, in reality, most fired heaters do not experience uniform heat transfer, and as a result, hot spots develop on the tubes. These hot spots cause coking inside the tubes which requires the heater be shutdown periodically to remove the coke and clean the tubes. Any shutdown to clean the tubes in a fired heater causes a substantial production loss. The owners want to extend the run length of fired heaters. Furnace Improvements has developed a new patented firing technology that provides uniform heat transfer to heater tubes. This technology can be applied to most fired heaters. Our patented technology reorients the burners at a slight angle away from the tubes. We are able to direct the hottest part of the flames and flue gases away from the tubes without affecting the heat transfer in any way. FIS has installed this in 5 heaters ranging from 14 MMBtu/hr. to 280 MMBtu/hr. The clients are experiencing significant reduction in tube metal temperatures. This is translating into lower coking rates and higher tube life. We have been able to increase the capacity of the heaters in most of the cases. In one of the case study that has been presented in this heater, the heater duty was increased from 14 MMBtu/hr. to 21 MMBtu/hr. Inclined firing improves the heat transfer to the tubes and makes in uniform.
Pre-reforming
Flow-schemes
Feed-stocks
Catalyst handling, loading & start-up
Benefits of a pre-reformer
Case studies
Effects upon primary reformer
Data analysis
Reactor temperature profiles
Catalyst management
Summary
Steam Reformer Surveys - Techniques for Optimization of Primary Reformer Oper...Gerard B. Hawkins
Introduction
Background Radiation and Temperature Measurement
Reformer Survey Inputs
Other Troubleshooting Tools
Safety
Preparation
Onsite Data Collection
TWT Survey
Observation/Troubleshooting
Modelling and Analysis
Results/Outputs
Case Studies
Conclusions
Case Study 1
Case Study 2
Case Study 3
Conclusions
This material provides the basic of design, operation and maintenance so that you can use this as guide line to operation, to inspect your boiler. Hope this will be benefit you.
Pre-reformer in the flowsheet
* positioned upstream of the steam reformer
* uses a specialized high activity catalyst based on Ni
* reaction involves conversion of hydrocarbons to a mix of CH4, CO, CO2 and H2
Pre-reformers - sometimes included at the original design stage
- also can be added to existing units to uprate the plant
Most modern ammonia processes are based on steam-reforming of natural gas or naphtha.
The 3 main technology suppliers are Uhde (Uhde/JM Partnership), Topsoe & KBR.
The process steps are very similar in all cases.
Other suppliers are Linde (LAC) & Ammonia Casale.
A case study on Process Condensate Stripper in Ammonia Plant by Prem Baboo.pdfPremBaboo4
A trouble shooting case study in Fertilizers unit, India.Solving the problem of Feed/Effluent Exchanger E-3321A/B in Process Condensate stripping section of Ammonia plant by Analytical approach. The problem solved by in house experts without changing the heat exchangers while others plant change the heat exchangers. Number of modification done and huge amount of energy saved. The paper intended how to save energy by changing heat exchanger and pressure of PC Stripper. The treated process condensate was earlier cooled by CW in final cooler from about 90ºC to 40ºC. This available heat of PC is being recovered by exchanging heat with DM water in a plate heat exchanger. The pressure of PC stripper has been raised to about 1.5 kg/cm²g to make the extra heat recovery possible. Now pressure is 41.5 kg/cm2. A new Plate heat exchanger was procured & installed for the heat recovery.
VULCAN Series VSG-Z101 Primary Reforming
Initial Catalyst Reduction
Activating (reducing) the catalyst involves changing the nickel oxide to nickel, represented by:
NiO + H2 <==========> Ni + H2O
Natural gas is typically used as the hydrogen source. When it is, the catalyst reduction and putting the reformer on-line are accompanied in the same step.
Burner Design, Operation and Maintenance on Ammonia PlantsGerard B. Hawkins
Burner Design, Operation and Maintenance on Ammonia Plants
Brief History
Reformer Burner Types/Design
Types of Reformers
Combustion Characteristics
Excess Air/Heater Efficiency
Maintenance, Good Practice
Low Nox Equipment
Summary
Purpose
Key to good performance
Problem Areas
Catalysts, heat shields and plant up-rates
Burner Guns
Development of High Intensity Ring Burner
Case Studies
Conclusions
Hydrogen Plant Flowsheet - Effects of Low Steam RatioGerard B. Hawkins
Effect of Low Steam Ratio on the Steam Reformer
Effect of Low Steam Ratio on H T Shift & PSA
Effect of Low Steam Ratio on Gross Efficiency
Effect of Low Steam Ratio on Net Efficiency
Alternative schemes for improving heat recovery
High level introduction
Mainstream syngas = steam reforming processes
Ammonia; methanol; hydrogen/HyCO
Town gas
Steam reforming; low pressure cyclic
Direct reduction iron (DRI)
HYL type processes; Midrex type processes
Improve fired heaters performance and reliabiltyAshutosh Garg
Fired heaters are often suffering from high tube metal temperatures and short run lengths. Operators are always worried about hot spots in the furnace. While refineries want to push the heaters hard, the heater starts coking up and very soon, the heater tubes have to be cleaned.
FIS has done extensive research and CFD modelling of heaters in the recent time and has concluded that localized burner flame and hot flue gas currents are responsible for the hot spots on the tubes. FIS has now developed a new patented technology for solving hot spot problems. This technology called Inclined Firing Technology involves orienting the burners at an angle on the floor / wall/ roof to direct the flame away from the tubes. The results of this technology have been extremely good and with a very low investment, the reliability and run length of the heater is improved significantly.
Fired heaters are used for heating hydrocarbons fluids in the refineries and petrochemical plants. They are used for high temperature heat transfer. In most fired heaters, we are burning fuel gas as source of heat . There are many heaters in the world where liquid fuel is also burnt in the fired heaters to provide the energy, but their number is decreasing due to tighter pollution laws. Heaters that are processing hydrocarbons services are prone to coking and cracking depending upon the nature of the hydrocarbons being processed. Typically heaters may run length of anywhere from 3 months for coking service to 6 years for different services. Heater designers and operators are always faced with the challenge of providing uniform heat transfer to all the tubes. Engineers use equations that assume uniform heat transfer to heater tubes When designing fired heaters. However, in reality, most fired heaters do not experience uniform heat transfer, and as a result, hot spots develop on the tubes. These hot spots cause coking inside the tubes which requires the heater be shutdown periodically to remove the coke and clean the tubes. Any shutdown to clean the tubes in a fired heater causes a substantial production loss. The owners want to extend the run length of fired heaters. Furnace Improvements has developed a new patented firing technology that provides uniform heat transfer to heater tubes. This technology can be applied to most fired heaters. Our patented technology reorients the burners at a slight angle away from the tubes. We are able to direct the hottest part of the flames and flue gases away from the tubes without affecting the heat transfer in any way. FIS has installed this in 5 heaters ranging from 14 MMBtu/hr. to 280 MMBtu/hr. The clients are experiencing significant reduction in tube metal temperatures. This is translating into lower coking rates and higher tube life. We have been able to increase the capacity of the heaters in most of the cases. In one of the case study that has been presented in this heater, the heater duty was increased from 14 MMBtu/hr. to 21 MMBtu/hr. Inclined firing improves the heat transfer to the tubes and makes in uniform.
Pre-reforming
Flow-schemes
Feed-stocks
Catalyst handling, loading & start-up
Benefits of a pre-reformer
Case studies
Effects upon primary reformer
Data analysis
Reactor temperature profiles
Catalyst management
Summary
Steam Reformer Surveys - Techniques for Optimization of Primary Reformer Oper...Gerard B. Hawkins
Introduction
Background Radiation and Temperature Measurement
Reformer Survey Inputs
Other Troubleshooting Tools
Safety
Preparation
Onsite Data Collection
TWT Survey
Observation/Troubleshooting
Modelling and Analysis
Results/Outputs
Case Studies
Conclusions
Case Study 1
Case Study 2
Case Study 3
Conclusions
This material provides the basic of design, operation and maintenance so that you can use this as guide line to operation, to inspect your boiler. Hope this will be benefit you.
Pre-reformer in the flowsheet
* positioned upstream of the steam reformer
* uses a specialized high activity catalyst based on Ni
* reaction involves conversion of hydrocarbons to a mix of CH4, CO, CO2 and H2
Pre-reformers - sometimes included at the original design stage
- also can be added to existing units to uprate the plant
Most modern ammonia processes are based on steam-reforming of natural gas or naphtha.
The 3 main technology suppliers are Uhde (Uhde/JM Partnership), Topsoe & KBR.
The process steps are very similar in all cases.
Other suppliers are Linde (LAC) & Ammonia Casale.
A case study on Process Condensate Stripper in Ammonia Plant by Prem Baboo.pdfPremBaboo4
A trouble shooting case study in Fertilizers unit, India.Solving the problem of Feed/Effluent Exchanger E-3321A/B in Process Condensate stripping section of Ammonia plant by Analytical approach. The problem solved by in house experts without changing the heat exchangers while others plant change the heat exchangers. Number of modification done and huge amount of energy saved. The paper intended how to save energy by changing heat exchanger and pressure of PC Stripper. The treated process condensate was earlier cooled by CW in final cooler from about 90ºC to 40ºC. This available heat of PC is being recovered by exchanging heat with DM water in a plate heat exchanger. The pressure of PC stripper has been raised to about 1.5 kg/cm²g to make the extra heat recovery possible. Now pressure is 41.5 kg/cm2. A new Plate heat exchanger was procured & installed for the heat recovery.
VULCAN Series VSG-Z101 Primary Reforming
Initial Catalyst Reduction
Activating (reducing) the catalyst involves changing the nickel oxide to nickel, represented by:
NiO + H2 <==========> Ni + H2O
Natural gas is typically used as the hydrogen source. When it is, the catalyst reduction and putting the reformer on-line are accompanied in the same step.
Burner Design, Operation and Maintenance on Ammonia PlantsGerard B. Hawkins
Burner Design, Operation and Maintenance on Ammonia Plants
Brief History
Reformer Burner Types/Design
Types of Reformers
Combustion Characteristics
Excess Air/Heater Efficiency
Maintenance, Good Practice
Low Nox Equipment
Summary
Purpose
Key to good performance
Problem Areas
Catalysts, heat shields and plant up-rates
Burner Guns
Development of High Intensity Ring Burner
Case Studies
Conclusions
Hydrogen Plant Flowsheet - Effects of Low Steam RatioGerard B. Hawkins
Effect of Low Steam Ratio on the Steam Reformer
Effect of Low Steam Ratio on H T Shift & PSA
Effect of Low Steam Ratio on Gross Efficiency
Effect of Low Steam Ratio on Net Efficiency
Alternative schemes for improving heat recovery
High level introduction
Mainstream syngas = steam reforming processes
Ammonia; methanol; hydrogen/HyCO
Town gas
Steam reforming; low pressure cyclic
Direct reduction iron (DRI)
HYL type processes; Midrex type processes
Improve fired heaters performance and reliabiltyAshutosh Garg
Fired heaters are often suffering from high tube metal temperatures and short run lengths. Operators are always worried about hot spots in the furnace. While refineries want to push the heaters hard, the heater starts coking up and very soon, the heater tubes have to be cleaned.
FIS has done extensive research and CFD modelling of heaters in the recent time and has concluded that localized burner flame and hot flue gas currents are responsible for the hot spots on the tubes. FIS has now developed a new patented technology for solving hot spot problems. This technology called Inclined Firing Technology involves orienting the burners at an angle on the floor / wall/ roof to direct the flame away from the tubes. The results of this technology have been extremely good and with a very low investment, the reliability and run length of the heater is improved significantly.
If you are working in refining or petrochemical industry, you need to learn about fired heaters. This paper talks about basic specifications of fired heaters. You can benefit by using good specifications to purchase fired heaters for your next project.
.Coker heaters are one of the most critical heaters in the refineries. The feed is heated to a very high temperature. Run length is one of the important factors for coker heaters. We have worked recently worked on a conventional Coker heater and implemented several improvements while retubing the radiant section.
Article written by Xavier D’Hubert, Combustion Consultant for Global Cement Magazine.
In this article each cement burner OEM was given the opportunity to present the main features of its burners as well as provide insight into design concepts and their evolution.
The emphasis is on the latest offering of each OEM, even though several still sell burners from previous generations. As not all OEMs responded, the exercise has been completed using information found in the available literature. For more information on the evolution of burner design trends, see the February 2017 issue of Global Cement Magazine.
AIChE Smart Stack Damper Design Provides Better Control of Fired HeatersAshutosh Garg
Stack dampers are one of the insignificant yet important component of fired heaters in the refining industry. Over 90% of the heaters in the USA are natural draft and are dependent upon the draft for efficient combustion of fuel gas with air. Stack dampers currently installed are highly oversized and are not able to control draft effectively. Furnace Improvements patent pending design overcomes these limitations and improves the damper control significantly by installing multiple actuators and changing the control characteristics of the dampers.
Air Preheat System Upgrade on Coker HeatersAshutosh Garg
Furnace Improvements design, engineered and revamped the existing air preheat system for a refinery in Houston. This paper was presented at an AIChE conference in October 2019.
Minimising emissions, maximising alternative fuelsA TEC Group
Dr. Stefan Kern, A TEC Production and Services GmbH, details the conversion of the kiln at Lafarge Retznei and shows how an optimised calciner design allowed for 100% alternative fuel usage.
"Minimising emissions, maximising alternative fuels". Article published on World Cement Magazine, edition June 2022.
Process Heaters, Furnaces and Fired Heaters: Improving Efficiency and Reducin...Belilove Company-Engineers
A process heater is a direct-fired heat exchanger that uses the hot gases of combustion to raise the temperature of a feed owing through coils of tubes aligned throughout the heater. Depending on the use, these are also called furnaces or red heaters. Some heaters simply deliver the feed at a predetermined temperature to the next stage of the reaction process; others perform reactions on the feed while it travels through the tubes.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
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Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
1. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 1
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
API 560
Changes in Burner Specifications
1
1st
, 2nd
, and 3rd
Edition- 10.1.1
Burner design and installation shall ensure against flame impingement on
tubes and tube supports when burners are operating at maximum heat
release.
4th
and 5th
Edition- 14.1.1
Burner design, selection, spacing, location, installation and operation shall ensure against flame impingement on tubes, tube
supports and flame exiting the radiant section of the heater throughout the entire operating range of the burners. The location and
operation of burners shall ensure complete combustion within the radiant section of the heater.
2
Added in 2nd
Edition 2nd
& 3rd
(10.1.2), 4th
and 5th
Edition- 14.1.2
Burners shall be designed in accordance with all local and national statutes and regulations.
3
1st
Edition- Table 11
Minimum Clearance for Burners in Natural Draft Operation
-Burner clearances specified for conventional burners only
2nd
and 3rd
Edition- Table 12
Minimum clearances for Natural Draft Operation-
a. The values of longitudinal clearances A and D for conventional burners mentioned in 2nd
edition table should be multiplied a
factor of 1.3 and 1.5 respectively to get clearances for Low NOx burners.
b. In 3rd
Edition clearances are specified directly for Low NOx burners. For conventional burners, the longitudinal clearances are to
be reduced by a factor of 0.77 and 0.67 respectively.
4th
(Table 13) and 5th
(Table 15) Edition
Minimum clearances for Natural Draft Operation-
-In addition to changes in 2nd
and 3rd
editions, the minimum natural draft clearances are also specified for Ultra Low NOx burners.
The values of longitudinal clearances (A & D) mentioned for Low NOx burners should be increased by 20%.
Inclined Firing System
Most tube failures in fired heaters occur due to high tube metal temperatures (TMTs). Flame impingement due to long burner flames results in higher TMTs and
coking that affect the performance of the heater. Furnace Improvements developed the patented Inclined Firing System (IFS) to reduce flame impingement on
heater tubes.
With this burner arrangement, a heater will have the following advantages:
• Elimination of hot spots
• Longer tube life
• Increased heater run lengths
• More uniform heat transfer along the tubes’ lengths
Lower coking rates of internal tube surfaces
2. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 2
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
4
Added in 4th
and 5th
Edition 4th
and 5th
Edition- 14.1.4
In addition to 14.1.3 (Minimum burner clearance for natural draft operation), the following shall apply-
a) The number and size of burners shall ensure that the visible flame length is a maximum of two-thirds of the radiant section
height. For floor-fired heaters the CO content at the bridge wall shall be a maximum of 40 ppm by volume for gas-fired heaters
or 80 ppm by volume for oil-fired heaters, at maximum design firing conditions.
b) For horizontal opposed firing, the minimum visible clearance between directly opposed firing flame tips shall be 4 ft.
5
Added in 4th
and 5th
Edition 4th
(Table 14) and 5th
(Table 16) Edition-
Minimum Clearances for Forced Draft Operation-
Horizontal distance to centerline of wall tubes from burner centerline is included.
6
1st
(10.1.3), 2nd
and 3rd
Edition (10.1.4)
Burners shall be sized for a maximum heat release at the design excess
air based on the following:
Burner Sizing 1st
– 3rd
Edition
Number of burners % of Normal Heat Release
Less than 5 125
6- 7 burners 120
Greater than 8 115
4th
and 5th
Edition (14.1.7)
All burners shall be sized for a maximum heat release at the design excess air based on the following:
Burner Sizing 4th
– 5th
Edition
Number of burners % of Normal Heat Release
Less than 5 120
6- 7 burners 115
Greater than 8 110
7
1st
Edition- 10.1.5
Gas pilots shall be provided for all burners firing liquid fuels
2nd
& 3rd
(10.1.6); 4th
& 5th
(14.1.9) Edition
Gas pilots shall be provided for each burner, unless otherwise specified
N 744 Boiler NOx Reduction Project
Furnace Improvements (FIS) was approached to convert a CO boiler in Unit 40 to be a standalone refinery fuel gas fired boiler, and reduce NOx emissions. The
existing boiler was revamped into a fuel gas fired boiler with a maximum capacity of 400,000 lb/hr of steam @ 625 psig, 750 °F and reduced the NOx emissions down
to 0.02 lb/MMBTU.
FIS developed a heat transfer model of the boiler. Analyzed the performance of the boiler with NOx reduction and provided the client with various options for NOx
reduction. They selected the option of ultra low NOx burners with external flue gas recirculation and steam injection into the burners.
FIS scope of services included the following:
1. Replace existing burners with new Ultra-Low NOx Burners and FGR Fan
2. Provide new Economizer: FIS installed a new economizer which increased the efficiency of the boiler
3. Steam Super Heater Modifications: The existing heat transfer surface was inadequate and steam temperature was to drop to about 680°F after the revamp.
4. Firebox Modifications: FIS maximized the heat transfer surface in the firebox by sealing the CO ports with water wall panels, and removing the refractory from
the floor and the roof.
5. New Attemperator: FIS installed a new attemperator to maintain a constant super heat temperature at all boiler loads.
3. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 3
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
8 Added in 2nd
Edition
2nd
& 3rd
(10.1.7); 4th
& 5th
(14.1.10) Edition
a) The pilot shall have a nominal heat release of 75,000 Btu/hr. The minimum heat release shall be approved by the purchaser if it is
for a high capacity burner whose heat release is 15×106
Btu/hr or greater.
b) The pilot burner shall be provided with a continuous supply of air, under all operating conditions. This includes operation with
the main burner out of service.
c) The pilot burner shall remain stable over the full firing range of the main burner. It shall also remain stable upon loss of main
burner fuel, minimum draught, all combustion air flow rates and for all operating conditions.
4th
& 5th
(14.1.10) Edition
In addition to above points, following two more points were included in 4th
and 5th
edition-
d) The pilot shall be positioned and sized to ensure that it is capable of lighting any of the main burner fuels. The purchaser shall
specify the minimum main fuel flow rate during cold-burner light-off.
e) The pilot shall be capable of relighting an individual main burner over the full range of fuels. The combustion air flow rate might
need to be reduced for satisfactory reignition, particularly for forced-draught and Low-NOx burners.
9 Added in 2nd
Edition
2nd
Edition- 10.1.9
Burner tiles shall be pre-fired to no less than 500°F (260°C)
3rd
(10.1.9), 4th
& 5th
(14.1.12) Edition
Burner tiles shall be supplied, pre-dried as required, so as to allow full firing after installation without further treatment. Burner tiles
fabricated from water-based and hydrous materials shall be pre-dried to no less than 260 °C (500 °F).
Improve the flame profiles in the heater and increase the run length to 5-6 years
The heater had frequent decoking requirement (every 2.5 years) and flames were impinging on the radiant tubes. CFD simulations were carried out for
the following cases to analyse the flue gas circulation pattern, flame characteristics and radiant tube metal temperatures. The existing case heater
section with large heat release per burner. FIS proposed to replace each large burner by 4 smaller burners.
Benefits achieved-
1. Significant reduction in radiant tube metal temperatures
2. Flame height is reduced by more than 50% for the proposed case
3. Average CO levels at each cross-section of the heater reduced considerably, showing a faster combustion and lower flame heights
4. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 4
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
10
1st
Edition (10.1.7), 2nd
Edition (10.1.11),
Burners shall have a turndown capability to at least 40% of the
normal heat release without adjusting the air controls
3rd
Edition
Deleted
4th
and 5th
Edition- 14.1.14
The burner shall maintain flame stability when operating at no less than 33 % of the maximum heat release settings without
adjusting the air controls.
11 Added in 2nd
Edition
2nd
& 3rd
(10.1.10); 4th
and 5th
(14.1.13)
The materials used for construction of a burner shall be chosen for strength, as well as temperature- and corrosion-resistance, for the
anticipated service conditions. Burner components shall be designed in accordance with the minimum requirements shown in Table
13 (2nd
/3rd
Edition) / Table 15 (4th
Edition) and Table 17 (5th
Edition).
Table 13 (2nd
/3rd
Edition) / 15 (4th
/5th
Edition)- Materials of Construction
a. In 3rd
edition the material 321L SS is replaced with 316L wherever it was specified.
b. In 4th edition, for fuel gas tip, where fuel content has >100 parts per million H2S and either >300° fuel or >400°F combustion air,
the construction material must be AISI 310 SS. In 3rd
edition for the same condition 316L SS material was specified.
c. In 4th
and 5th
edition wherever mineral oil is specified to be used, it is specified that Castables shall be used for oil firing were
surfaces can be soaked with fuel oil.
12 Added in 2nd
Edition
2nd
(10.1.12); 3rd
(10.1.11); 4th
& 5th
(14.1.15) Edition
At maximum design, the burner shall be selected to use no less than 90 % of the maximum available draught loss for the maximum
specified heat release.
Combustion Modeling of Heater using CFD
The Existing configuration had issues of flames leaning towards the radiant tubes and impingement of hot flue gases
on radiant tubes.
CFD simulations were carried out for the following cases:
• Existing case:
Quarter heater with three burners
• Proposed case:
Similar configuration; burners with higher air side pressure drop and inclining towards the centre of the heater
Benefits-
• Hot flue gas recirculation near the tubes has reduced in the proposed case
• Significant reduction in maximum tube metal temperature
5. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 5
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
13 Added in 2nd
Edition
2nd
(10.1.14); 3rd
(10.1.13); 4th
& 5th
(14.1.17) Edition
If a natural-draught burner is to be used in forced-draught service, the purchaser shall specify the required heater capacity during
natural-draught operation, if required.
14
1st
Edition- 10.1.9
Burners and gas rings or tips and oil guns shall be removable while
heater is in operation
2nd
(10.1.19) and 3rd
(10.1.18) Edition
Gas manifolds and oil guns shall be removable while the heater is in operation. Purchasers must specify whether they require
removal of the diffuser or the complete burner assembly.
4th
and 5th
Edition 14.1.21
Oil guns shall be removable while the heater is in operation
4th
and 5th
Edition 14.1.22
The purchaser shall specify whether gas guns, diffusers or the complete burner assembly shall be removable.
15
1st
(10.1.10), 2nd
(10.1.15), 3rd
(10.1.14)
Natural draft oil burners shall include double refractory tiles to
maintain flame stability when firing heavy fuels such as vacuum or
atmospheric-reduced crude oils, tars, or other high viscosity fuels
requiring preheat.
4th
and 5th
Edition
Deleted
16 Added in 2nd
Edition
2nd
(10.1.16/17), 3rd
(10.1.15/16), 4th
and 5th
(14.1.18/19)
-Oil burners shall be designed to operate on a maximum oil viscosity of 43 cs (200 SSU).
-Atomizing steam shall be supplied dry at the burner, or with slight superheat.
H-28 Vacuum Heater Performance Improvement Study
A refinery was facing coking problems in their Vacuum Heater. In addition, they also wanted to revamp the heater to handle Canadian Crude and reduce NOx emissions. FIS did the process
study and because of the study, the client decided to build a new Vacuum heater with an existing heater foundation. The new heater is 4 ft wider.
This vacuum heater is a horizontal tube box with a convection section. It is designed for a heat duty of 43MMBtu/hr. FIS’ scope involves design, engineering, structural analysis and supply of
this heater to the site. The heater has an efficiency of 90%.
It was successfully commissioned in March 2009. The heater was delivered within 7 months of starting the job.
We received the following feedback from Client.
“.. we talked about the performance of the VF4 H28 heater since startup. It has been fantastic! The stack temperature is 370-380°F and the fuel gas usage has dropped about
40% from the old heater. This is one of the most efficient heaters in the refinery. The NOx stack testing came back 0.026 lb NOx/MMBtu, which is also outstanding. They are
even trying to reduce the O2 even lower, from 4% to 3%. It's a lot different when you have a tight firebox. Great job!!!”
-Client
6. API 560 Standards Comparison
Furnace Improvement Services, Texas
Furnace Improvements
www.heatflux.com
Uniform Heat Transfer for Fired Heaters 6
Inclined Firing System Split Flow Technology Flue Gas Injection Draft Control System
Furnace Improvement Services
Furnace Improvements Services is a reputed engineering and consulting company which
provides specialized technological services that integrates mechanical and process
engineering with CFD capabilities to design or revamp fired heaters and boilers in Oil &
Gas industry.
Offices
• Headquarters: Sugar Land, Texas, USA
• Process & Mechanical Group: New Delhi, India
• CFD & Process Group: Pune, India
Services
• Turn-key services for design, engineering and supply of new fired heaters
• Revamps of all types of refinery fired heaters
• CFD Modeling
• Troubleshooting