h2so4 - understanding spray technology to optimize sulfur...
TRANSCRIPT
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Chuck Munro
Dan Vidusek
Understanding Spray Technology to Optimize
Sulfur Burning!Presenters:
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• 75 year nozzle engineering & manufacturing company • Leader in spray technology • Manufacturing facili;es in 9 countries • Global sales and support • More than just nozzles:
• headers • injectors • spray controls • spray research & tes;ng
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About Spraying Systems Co.!
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It always starts with the nozzle � �• � � a� � � •� �� •� � � � � � � a� � e� � � � � � � e� � � � � � �•� � � � � � � � � � ••e � � � � � �• � � � a� •� � e� � � � � � � �� � � � � � � � � � � � � � •� z� �•� � � e� � r � � � �� •� � � � � � � •� �o � � � a� �� � �• � � � � � � zz� � � � •� � � � � � � � � � � � � � � � � � ••� u� ��� •� �� � � � � � � � � � � � � � � � � � � o� ��� � � •� •o• � � � � � � � � �� � � �
� � � � � � zz� � � � •� � � � � � � � � � � � � � � � � � ••� u� ��� •� �� � � � � � � � � � � � � � � � � � � o� ��� � � •� •o• � � � � � � � � �� � � �
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Hydraulic Atomizer Types!
Flat Spray!
Hollow Cone!
Full Cone!
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Hollow Cone Spray!
• Spray is formed within the nozzle by an inlet that is tangential to a whirl chamber "
• The resulting whirling liquid forms a hollow cone as it leaves the orifice "
• Large free passages for good clog resistance"
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Sulfur Burning Nozzle!
• 1/2BA-309SS70"— Hollow cone spray pattern"— Small to medium sized
droplets"— Large, unobstructed flow
passages to minimize clogging"
— Relatively low cost to operate "
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LIQUID"
GAS"
Air Caps"
• � �• � � � � � � � � e� � � � � � � � n� � � � � � �� � � � � � �� � � � �� � g� �•� � o� � n� •� � � � � � � � � � �� � � � � � � e� � � •� �o � � �y � � �• � � � � �� � � � zz� � � � � � �� � � •7� •i�f � � � � � • � � � � � •� z� �f � � � r � � � � � •� z� � •� � � e� �f � � •� 7a� � � � � � �� � � •� � � � � � � �7 � � � � � ••e � •�f � � � � � � � � � � �• •�� � �f � � �7 a� � o� � � � � � � •� • �� � � � � � � � � � � � � � �
� � � � � � � � � � � � � � � � � � � � � �
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High Volume Dual Fluid Nozzle!
� � � � � � � � � � � �� � •� � � � � � � � e� � �� � � a� � � � � � � � ��� � e� e•� �� � � r � � � � � � � � �a� � � � � o� �� � � � •� � � � � � �� � � e� � � � � � e� � &�
� � � � � � � � � � � �� � � e•� � � • � �� �� � � �� •� � � � � � � � � � �� � � � � � � �� � � 7 � � �� �� � � � �� � � �� � � �� me� &�
Stage Three: ���� � •� � �� � �� •� �• � �� � � �� �� � n� � � � � � � � � &�� � ••e � � � � � � �� � ••�� � � � � •� � � a� � � •� � � �� �� � � � z�7 � � &�
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Common factors affecting molten sulfur atomization!
• Plugged Nozzles"• Spray Atomization"
— Sulfur Carryover"• Turndown"• Gun Design"
— Sulfur temperature consistency"— Steam migration into sulfur line"
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Nozzle Pluggage!• “Carsul” or other contaminants in the molten sulfur can
buildup and plug nozzle orifices. These unwanted particles can be of different sizes, so maximizing the free passage for a particular type of nozzle is critical."
• Particulates can harden at the exit orifice from residuals during low flow or shut-down procedures.""
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Spray Atomization!• Atomization is ‘Key’ to successful and proper combustion."
• If the molten sulfur droplets are too large, they do not vaporize in time and can carry over and cause problems downstream. "
• It is important to have the sprayed droplet sized correctly so that the burner is run most efficiently. "
• Computational Fluid Dynamics (CFD) is an excellent tool to model optimum droplet size."
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Turndown!• A large turndown of the nozzle(s) flow rate is required for
startup and low production times and also to accommodate peak production. "
• Can be achieved by:"— Adding or removing guns"— Adjusting operating pressure of the guns / nozzles"
• Greater Turndown AND producing smaller droplets can be achieved with two-fluid nozzles."
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Gun Design!• Allow for thermal expansion and to withstand temperature
loading without bending."
• Steam recirculation for tight control of molten sulfur temperature and associated physical properties "
• Design criteria should stipulate that proper testing and validation is performed and welders are properly trained."
"• Critical that each pathway (molten sulfur, atomizing
medium, jacketing steam) are isolated from each other."
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Injector Design Hydraulic Sulfur Gun!
Sulfur-Burning Injector 53686-001
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Injector Design Two-Fluid Sulfur Gun!Injector DesignTwo-Fluid Sulfur Gun
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Increase in Surface Area!
100 µm
Mass transfer is proportional to the droplet surface area!"
150 µm
200 µm
250 µm
300 µm
400 µm
500 µm
2012 P&P: Crude/Vacuum Distillation & Coking"
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Atomization Mechanics!
• Primary Break-up"— Conical Sheet"
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Atomization Mechanics!
• Secondary Break-up"— Droplet Break-up"
Source: University of Darmstadt, Germany
Series of photos showing “bag break-up” of a liquid drop ( Courtesy: Laurence Livermore National Laboratories, USA)
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Are all nozzles created equal?!
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Furnace CFD Set-up!
Top View!
Side View!
Main Inlet
• Air"• Q = 308,000 Nm3/hr"• ṁ = 113.9 kg/s"• T = 122ºC "• Poperating = 11 barg
"
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Outlet!Tout ~ 1160ºC
!Injections!• (6x) 53686-001 injectors with
1/2BA-309SS70 WhirlJet® nozzle"• Liquid sulfur"• Qtotal = 29 m3/hr"• ṁtotal = 14.6 kg/s (2.4 kg/s per nozzle)"• T = 132ºC"
Secondary Inlets
• Air
• ṁtotal = 1 kg/s
• T = 122ºC
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Temperature Profiles!Temperature
(� C)
2000
1075
150
T OUT = 1434 (� C)
Temperature Injection Planes!
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Species Content (Sulfur)!Mass Fraction Sulfur
.063
.032
.000
Sulfur Combustion Prior to Baffle Wall
Full Combustion Prior to Outlet
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Species Content (Oxygen)!Mass Fraction Oxygen
.063
.032
.000
Oxygen Depleted Prior to Baffle Wall
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Spray Visualization!
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Furnace CFD with FloMax nozzles!
Injection Parameters! Liquid: Molten Sulfur! Per nozzle! units! Flomax® FM5A!
Liquid Flow Rate" lpm" 80.5!
Liquid Mass Flow Rate" kg/s" 2.44!
Liquid Temperature" °C" 132!
Droplet Velocity" m/s" 35!
Spray Angle" °" 55!
DV0.01 - Minimum" μm" 11!
DV0.50 - Average" μm" 66!
DV0.99 - Maximum" μm" 144!
N (RR spread parameter)" -" 2.4!
2.5 m!
!
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Temperature profile!Temperature
(� C)
2000
1075
150
T OUT = 1547 (� C)
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Species Content (Sulfur)!Mass Fraction Sulfur
.063
.032
.000
Sulfur combustion not complete prior to baffle
wall
Full Combustion Prior to Outlet
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Species Content (Oxygen)!Mass Fraction Oxygen
.063
.032
.000
Oxygen Depleted Prior to Baffle Wall
Secondary Air Imbalance in Oxygen
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Spray Visualization!
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CFD Conclusions!Velocity!• Good alignment with velocity
contours of inlet air - Hydraulic"
• Poor alignment with velocity contours of inlet air - Hydraulic"
Wall Impingement!• Impingement with base of
combustion chamber - Hydraulic"
• No impingement with base of combustion chamber – Dual Fluid"
combustion chamber - Hydraulic
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Nozzle Comparison!Issue! Hydraulic!
1/2BA-309SS70!Air Atomizing!FM25A!
Flow Rate" 28 gpm @ 150 psi" 28 gpm @ 70 psi"(60 scfm constant air)"
Approx. Turndown" 3:1" 6:1"Free Passage" 0.375”" 0.250”"Drop Size (@ 28 gpm)" Dv0.90 = 754 mm" Dv0.90 = 300 mm"
Although the hydraulic nozzle has a larger free passage area, the air atomizing nozzle provides smaller droplets at a greater turndown ratio."
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In Summary…!• Begin with the end in mind!"• Nozzle wear affects spray droplet
performance."• Think in terms of drop size
requirements."• Use CFD when many factors
influence the spray."• Contact Spraying Systems Co.
early to help solve your spray application."
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Thank You!!