Post on 27-Feb-2023
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Excess Air/Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Usage of Fuels on Ammonia Plants Worldwide
0
50
100
150
200
250
300
350
400
450
Total NoPlants
Natural Gas Heavy FuelOil
Naphtha Syngas Others
Fuels
Num
ber
of O
pera
ting
Plan
ts
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CURRENT LEGISLATIONLIMITS
Country Start Year Heat releaseFurnace Capacity
NOx CO (ppm) Particulatesmg/Nm3
Gas Oil Gas Oil Gas OilFrance 1998 >170 MMBtuh 171 219 - - 5 50UK 1998 Any 146 219 115
1999 Any 97 171 80Germany 1996 <170 MMBtuh 122 80
219 85 50<340 MMBtuh 97 50 5
TA Luft >170:<1020mmBtuh
171 219 25 87 5-100 50
97 171 25 87 5-100 50Market demand All 39 73 5 50
171 5 50EasternEurope
As Germany
Italy 1992 >170:<1020mmBtuh
171 219 5 50
USA - All 30-100
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Brief History Burner design Burner Types Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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◦ Historically trial and error
◦ Empirical methods now backed up with the following sciences Chemical engineering Process engineering Thermodynamics Materials engineering
◦ A good understanding of the above creates good combustion
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◦ Computational fluid Dynamic’s (CFD) is playing a strong role. Good but be cautious
◦ Can be difficult to predict upsets Good for replacing flow modelling Model the Burner and the Furnace box to
ensure best possible results
◦ Becoming an essential tool for waste incineration predictions
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Burner testing in the manufacturer’s facility should always be considered
Confirms burner performance Turndown CO,CO2,NOX Etc Always use the specified fuels
that are to be used in service Highlights flame envelope and
lift off limits, pilot/light up issues.
Air flow distribution
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Brief History Burner design Types of Reformers Reformer Burner Types/Design Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Natural Draft Forced Draft Premix Post Mix Low Nox ◦ Fluegas Recirculation ◦ Staged Air ◦ Staged fuel
Single fuel/Dual fuel
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Gas Nozzle
Primary Air
Primary Air
Pre-Mix Burners
Venturi
Primary Fuel
• Fuel & air mixed before combustion zone
• Fuel pressure drop occurs in the nozzle.
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Nozzle Mix Gas Burner Included
Angle
Burner Block
Burner Throat
Port Circle Heater Refractory
Flame Holder
Pilot Gas
Air
Fuel Connection
FUE
L
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Nozzle Mixing Gas Burner Advantages
• No possibility of flashback
• To some extent, the ability to burn a wide variety of fuels with differing heating values.
• A high turndown ratio
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Increasing excess air
• reduces flame length • reduces particulates • increases NOx to a peak, further introduction of air leads
to a reduction
• Increasing liberation • increases flame length
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• Increasing fuel viscosity
• increases flame length • increases particulates • reduces NOx levels
• Increasing combustion air temperature • reduces particulates • increases NOx levels
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Draught Inches WG-13
-27-41
-55
Top firebox
Bottom Firebox
FD Section
Atmosphere
AfterConvection
After damper
After ID Fan
Atmosphere
1327
4155
83
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Burners can be maintained on or off line ◦ On line less popular due to safety concerns, guns
can be with drawn ◦ basic tip changes can be carried out ◦ potential to change burner settings
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◦ Off line during shutdowns (every 3-4 years)
◦ Relatively easy to perform Need for access
◦ Important to maintain settings tile to gun position tip port dimensions surface finish of holes centricity of gun condition of tile and security of fixings condition of metallurgy (oxidation)
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Check Burner gas Pressures ◦ at the burners, not the just the rail
pressure Check Combustion air pressures ◦ All to often the system is not balanced
correctly For oil firing ◦ it is very important atomising steam is dry
and at the correct temperature
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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◦ Currently being fitted on new plants ◦ More difficult to control ◦ The very nature of low Nox burner designs requires
the flames to be produced in a much slower manner ◦ Even more sensitive to dimensional changes during
maintenance, burner’s tend to be more complex ◦ Flames tend to be less well defined, with large
whispery edges
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Types ◦ Staged Air ◦ Staged Fuel
◦ Flue Gas Recirculation
Integral with the burner external to the burner
◦ Combination of all above
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Brief History Reformer Burner Types/Design Types of Reformers Combustion Characteristics Heater Efficiency Maintenance, Good Practice Low Nox Equipment Summary
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Good Combustion, this can only be achieved if the following is considered.
Attention to detail ◦ Good maintenance ◦ Good operation ◦ Good design
Partnership between:- Operation, Maintenance and Design.
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◦ You've carefully thought out all the angles ◦ You've done it a thousand times
◦ It comes naturally to you
◦ You know what you're doing, its what you've
been trained to do your whole life ◦ Nothing could possibly go wrong, right ?
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