Baukal, Jr., is director of the John Zink Institute for the John Zink Co. LLC, Tulsa, Oklahoma, where he has been since 1998. John Bellovich is manager of the Combustion Rental Group at John Zink Company LLC, Tulsa, Oklahoma.
Ping Chung, PhD, is a senior development engineer in the Technology and Commercial Development Group at
Introduction
In a natural draft burner, the air enters through a sound suppression section whose primary function is to dampen the sound of the burner. It serves to distribute air to the burner neck and dampen the sound of the firebox.
Classification Based on Emissions
- Conventional Burners
- low-NOx Burners
- ultralow-NOx Burners
The first combustion zone includes all fuel and air supplied through the primary oil tile and the secondary tile throat. In this design, the ratio of the first combustion zone to the second combustion zone is effectively fixed by the burner design.
Flame Shape: Round versus Flat and Freestanding versus Wall-Fired
- round Flame Burners
- Flat-Flame Wall-Fired Burners .1 PXMR Burner
- Flat-Flame Freestanding Burners .1 PXMR-DS Burner
A typical burner for shot reformer service is the John Zink MDBP, shown in Figure 1.28. Applications that require higher heat release for burners such as steam cracking, are best served with the PSFFR John Zink combustor, shown in Figure 1.32.
Radiant Wall Burners .1 Premix radiant Wall Burners
- raw gas radiant Wall Burners .1 FPMR Burner
The burner's fuel pressure is used for aspiration and mixing of the combustion air with the fuel. Prior to the initiation of the combustion reaction, both the fuel and the air are mixed with high-temperature inert furnace gases.
Combination Gas and Oil Firing
- atomization Systems (Oil guns)
- Combination Burner
Within the core and outer tip, a complete emulsification of the oil with the atomizing medium occurs. The oil gun is located in the center of a primary plate, also called a "regen plate". Gas cooking is provided through multiple tips located around the oil plate, in the secondary area of the plates.
Pilot Burners
- Premix Pilots
- Flame Detection
- ignition
Gas intake from the furnace occurs due to this staggered arrangement of air slots and gas tip protective blocks. However, due to the barrier created by the electrode and insulators, the efficiency of the mixer is less than that of the ST-1-S.
Introduction
Process Oil Burner
- Oil gun Type
- Oil Flame Stabilization
- Flame Shape
- emission Considerations
The figure illustrates that for the same fuel pressure, the oil gun delivers more fuel flow. These recirculation zones return burning fuel/air mixtures and hot combustion products to the exit ports of the oil gun distribution point.
Boiler Oil Burner
- Oil gun Types
- Oil Flame Stabilization
- Flame Shaping
- emission Considerations
Nitrogen oxide (NOx) emissions will mainly come from some of the elemental nitrogen compounds in the fuel and thermal NOx. The opacity is a direct result of particulate emissions and is caused by the light scattering of the fines in the chimney exhaust.
Oil Burner Performance
- Flame Dimensions
- Turndown ratio
- NOx emissions
- Particulate emissions
- Noise level
The NOx emission for oil combustion is a function of furnace temperature, combustion air temperature, O2 level and oil gun operating conditions. Particulate emissions are a function of furnace temperature, combustion air temperature, O2 level and oil gun operating conditions.
Burner Performance Predictions
- Droplet and Carbon Burnout
- emission Formation and Prediction
After, and partly during, gaseous oxidation, the original droplet becomes empty of hydrocarbons and becomes a charred "particle". The particle can be a solid sphere or a hollow senosphere, depending on the original droplet size and fuel properties such as Conradson carbon or asphaltene content. Kr is the surface reaction coefficient in cm/s Km is the diffusion coefficient in cm/s and.
Oil Burner Maintenance .1 Oil Burner
- Oil gun
Next, loosen the three screws located at the back of the oil gun guide tube. Oil spill - external inspection of the port region will reveal much about the condition of the oil spill.
Troubleshooting the Oil Burner
- effect on Operations
- lack of atomizing Pressure
- lack of atomizing Flow
- Wet Steam
- Cold Oil (Heavy Oil)
- Tip/atomizer Failure
- regen/Diffuser Failure
- low Oil Flow/low Oil Pressure
- High atomizing Pressure
- leaking Crossover Valve
- High Steam Temperature
- incorrect Positioning of the Oil Tip
A complete discussion of disassembling and cleaning the "EA" series oil gun is covered in the maintenance section. For details on disassembling, inspecting and cleaning the oil gun, see the maintenance section.
Introduction
For liquid fuels, the situation was somewhat similar, except that the droplet evaporation phase preceded the bulk of the fuel oxidation. These modifications resulted in new low-NOx concepts applied to the industrial burner design and new low-NOx concepts (see Volume 1, Chapter 15) of the overall combustion process inside the furnace, which, where possible, are used together to achieve the desired performance.
Burner Design Fundamentals
Many other components, such as the air plenum around the burner – the wind chamber – may be integral to the combustion system, but not a single burner. Since fan power (see Volume 2, Chapter 3) is also dependent on burner differential pressure, use.
Techniques for Reducing NOx Formation Two molecules, nitrogen oxide (NO) and nitrogen
- Flue-gas recirculation and injection of Steam into the Flame
- air Staging
- Fuel Staging
- lean Premixed Combustion
- Furnace gas Circulation and Combining Different Techniques
In the latter case, the FGR can be strategically directed to the parts of the flame where it is most effective. The rest of the air is supplied to the combustion after the combustion products lose a significant amount of heat.
Burners for Package Boilers
- Conventional round Burners and Burners with air Staging
- Burners with Fuel Staging
- Burners with Partial lean Premixed Combustion
- Premixed Burners
- Burners for low Heating Value gaseous Fuels and Fuels with Highly Variable Composition
- Oil atomizers for Package Boilers
The burner was the first in the industry to create simulated lean combustion in a significant portion of the flame. Another premix burner, the QLA burner, primarily uses fuel gas jets to create a weak swirl of the combined fuel, air, and FGR mixture.13,19 This burner is designed with variable geometry—the area of the burner where the premix enters the combustion zone is modulated with the firing rate.
Burners for Enhanced Oil Recovery Boilers
At a high fire, sprayers in package boilers usually consume steam in the amount of 10-18% of the weight of fuel oil. An ultra-low NOx burner, the QLN™-II burner, has been developed for this market and can operate at less than 5 ppm NOx. .
Burners for Multiple Burner Process Steam Field-Erected Boilers
The burner is equipped with an external gas collector with gas nozzles (gas nozzles). The external gas distributor allows replacement or servicing of attachments without dismantling the burner.
Gas and Oil Burners for Utility Boilers Steam cycles of fossil fuel fired utilities have much
- Combustion Systems for Oil and gas Wall-Fired utility Boilers
- Combustion Systems for Corner- Fired (T-Fired) Boilers
- Oil atomizers for utility Burners
0.5% to 0.6%, the effect of FGR may not be significant if the thermal NOx component is low, as illustrated by the test data in Figure 3.36. As the boiler load modulates, the relative intensity of heat transfer in the superheater changes.
Specialized Burners .1 Warm-up Burners
- Flue-gas reheat Burners
As the boiler load changes, so does the exhaust gas temperature, requiring heat to be added to the flow during some or all regimes. A key feature of the design is the sufficient delay in the mixing of the combustion products of the burner with the surrounding flue gases in various operating scenarios.
Summary
Skopp, Stationary Sources and Control of Nitrogen Oxide Emissions, in Proceedings of the 2nd International Clean Air Congress, Academic Press, New York, pp. NOx Controls for Utility Boilers, in Proceedings of the Electric Power Research Institute, 7-9. July, Cambridge, MA, 1992.
Introduction
Applications .1 Cogeneration
- Combined Cycle
- air Heating
- Fume incineration
- Stack gas reheat
This arrangement is only suitable if the air is used in a combustion process as it will contain products of combustion from the duct burner. Exhaust steam from the steam turbine is cooled and turned back into water (condensate) which is returned to HRSG Steam.
Burner Technology
- in-Duct or inline Configuration
- grid Configuration (gas Firing)
- grid Configuration (liquid Firing)
However, instead of multiple discharge points along the pipe length, liquid fuel is injected downstream of the element through the side wall of the channel and directed parallel to the flame holders (cross flow to the TEG). This configuration uses the diameter of the duct to contain the flame length, thus allowing a shorter distance between the burner and downstream boiler tubes (see Figure 4.10).
Fuels
- Natural gas
Pilots and igniters are particularly susceptible to the effects of moisture due to the small fuel openings, tight gap tolerances of the igniters, and the integrity of the insulation required to prevent them. Solid particles can clog the gas ports or other fuel system components and should be removed as much as possible.
Combustion Air and Turbine Exhaust Gas .1 Temperature and Composition
- Turbine Power augmentation
- Velocity and Distribution
- ambient air Firing (air-Only Systems and HrSg Backup)
- augmenting air
- equipment Configuration and Teg/
The TEG temperature is also reduced in installations where the HRSG manufacturer splits the steam superheater and places the tubes in front of the channel burner. Channel burners are usually installed in the TEG channel before or after the first set of heat transfer tubes.
Physical Modeling
- CFD Modeling
A bluff body plate, with or without perforations, is attached to the tube to protect the flame zone from the turbulence of the exhaust gas channel. Modifications to the design for lower emission performance generally have a larger cross-section in the plane perpendicular to the exhaust flow.
Emissions
- Visible Plumes
- NOx and NO vs. NO 2
- CO, uBHC, SOx, and Particulates
Distillate oil is the most common oil fired in channel burners as a liquid fuel. Km is the diffusion coefficient of oxygen in nitrogen Kr is the reaction coefficient of the form Ae−E/RT A is the frequency factor.
Maintenance
- accessories
But care must be taken with large volumes to ensure that temperature and concentrations are uniform. Automatic fuel cut-off upon detection of flame failure, loss of TEG/combustion air and high or low fuel pressure.
Design Guidelines and Codes .1 NFPa 8506 (National Fire
- Factory Mutual (FM)
- underwriters laboratories (ul)
- american National Standards institute (aNSi) B31.1 and B31.3
- Others
PI = Pressure Gauge PSH = High Pressure Shutoff PSL = Low Pressure Shutoff V1 = Manual Shutoff Valve V2 = Burner Flow Control Valve Figure 4.23. PI = Pressure Gauge PSL = Low Pressure Shutoff ST = Cleaner or Strainer V1 = Manual Shutoff Valve V3 = Igniter Safety Shutoff Valve V6 = Igniter Flow Control Valve.
Introduction
Fuels .1 Fuel Oils
- low-Sulfur Marine gas Oil
- lNg Boil-Off gas
- Produced Fuel gas and Crude Oil
Auxiliary Boiler Applications .1 Small “Donkey” auxiliary Boilers
- Water-Tube auxiliary Boilers
This gives a well-controlled flame shape and rotation up to 10:1 with the ability to adjust the air/fuel ratio throughout the burner range. The burner is fired with excess air at an MCR of typically 15% (providing . ~3% oxygen in the boiler exhaust) to ensure complete and clean combustion of the remaining heavy fuel oil.
LNG Carriers
- lNg-Carrier Main Propulsion Boilers
- lNg-Carrier gas Combustion units
The primary function of the GCU is to burn the BOG safely while maintaining an exhaust temperature below 535°C (995°F), a number chosen taking into account the auto-ignition temperature of methane by a 50°C (90°F) margin. The GCU is sized for the maximum BOG rate of the cargo tanks, which is based on the warranty value of the tank design.
Offshore Applications .1 FPSOs
- FSOs
- Floating lNg
Burner ignition is usually by direct high-energy spark from the main fuel, in the. The firing of the fuel gas on the auxiliary boilers is the same as for an FPSO; however, as the fuel gas is cooled (due to the feed lying on the seabed), any condensed liquids (water and hydrocarbons) must be removed before use in the boilers.
Introduction
Furnace Components
- Firebox
- refractory
- radiant Tubes
- Burners
- Convection Section
- Fans, Stacks, and Dampers
Fans can be used to supply air to the burners (forced draft) or extract flue gas from the heaters (induced draft) or both (balanced draft). It is controlled by means of a damper located in the duct leading to the stack or fan.
Common Heater Types .1 general
- refining Heaters .1 Refining Heater Design
- Delayed Coker Heaters .1 Coker Heater Design
- reforming Heaters
- Steam Cracking Furnaces .1 Cracking Furnace Design
In that case, the pipes are located in the center of the combustion chamber with burners on either side of the coils. Radiant coils are located in the center of the combustion chamber with burners located on both sides to provide uniform heating.
Process Heater Design .1 radiative Heat Transfer
- lobo–evans Method
- refinements of the lobo–evans Method
- air Heater Features
As is the total surface area of the radiant tubes (not the effective surface area of the heat sink). This can be achieved in different ways depending on the size and placement of the air heater.
Indirect Fired Systems
Air Heater Types .1 gSX air Heaters.1 gSX air Heaters
- VTK Heater
- VTN Heater
- Hg-WT Heaters
The main part will be recycled back into the combustion chamber by means of a recirculation fan. The incoming process air flows in the pipes in countercurrent to the flue gases (see figures 7.16 and 7.17).
