An atomizing oil burner breaks a liquid-fuel stream into a spray before combustion. This illustration shows a conceptual external-mix arrangement: oil travels through a central tube, atomizing steam through a surrounding passage, and the two meet outside the tip. The calculator compares entered velocities; it does not predict burner performance.
Crude Petroleum Burner Interactive Calculator
Compare oil and atomizing-steam velocities, their difference, and their constant-speed travel over 10 ms. The section shows separate passages meeting outside the nozzle.
Equation Used
- Positive entered velocities are compared as scalar speeds.
- Each 10 ms travel result assumes its entered speed remains constant.
- No nozzle dimensions, pressure or fluid-property model is supplied.
- Illustrative spray is not a droplet distribution or combustion calculation.
- Flow markers are slowed separately for visibility.
The results compare the two entered velocities and their travel over 10 ms at constant speed. They do not predict droplet size or burn time.
Follow the two separate flow paths
The section shows the center oil passage and two cuts through an annular steam passage. The upper and lower steam channels belong to the same space around the oil tube. The surrounding throat gives the nozzle its burner context. Spray is shown downstream, without a simulated flame.
Oil and steam markers are separately slowed to make both streams visible. Their displayed speeds do not share a scale. The spray dots are illustrative: their diameter, number and distribution are not calculated from the velocity controls.
Atomizing-medium arrangements
Oil guns can use steam or air atomization, and manufacturers distinguish internal- and external-mix designs. The displayed section illustrates external mixing with steam selected as the atomizing medium. It is not a dimensioned drawing or a model of a specified commercial gun.
Velocity and constant-speed travel
The velocity difference is Δv=vsteam−voil. The speed ratio is vsteam/voil. These are scalar comparisons of the entered values.
At a constant speed v in metres per second, distance in 10 milliseconds is v×0.010 metres, or 10v millimetres. The two travel cards apply this conversion to the oil and steam separately. They are comparison distances, not nozzle dimensions or calculated residence times.
Droplet size and burn time cannot be established from these two velocities alone. The travel cards show how far each stream would move in 10 ms if its entered speed remained constant.
Example velocity comparison
With oil at 2 m/s and steam at 300 m/s, the difference is 298 m/s and the speed ratio is 150. If those velocities stay constant for 10 ms, the corresponding travel is 20 mm for oil and 3000 mm for steam.
Doubling the oil speed doubles its 10 ms travel and halves the steam/oil speed ratio at unchanged steam speed. It does not establish a change in droplet size or combustion time.
What these inputs do not determine
The two controls provide no fluid properties, nozzle geometry, pressure, temperature, mass flow or combustion conditions. A numerical speed ratio therefore does not establish atomization quality, flame stability, fuel consumption, heat input or emissions.
Real atomizer behavior depends on the design and operating conditions. The illustration explains the flow arrangement while the calculator remains a kinematic comparison of the two entered speeds.
Oil-atomizer questions
Are the oil and steam mixed inside this drawing?
No. They remain in separate passages until they leave the tip.
Why are there two steam channels in the section?
They are opposite sides of an annular passage surrounding the center oil tube.
Are the spray dots a droplet-size result?
No. They illustrate dispersion only.
Why are there no burn-time or droplet-size estimates?
Those require a justified atomization or combustion model and additional data. Two stream velocities alone are insufficient.
References
Faber Burner Company: Oil Guns, Bulletin OG-1A describes steam/air atomization and internal/external-mix options. EPRI: Opacity Control Guidelines for Oil-Fired Plants, section 4, discusses the dependence of spray characteristics on atomizer design and conditions.
Gardner D. Hiscox: Mechanical Movements, Powers, Devices and Appliances, figure 215, printed page 66, shows an early oil burner with a central oil nozzle and annular compressed-air supply. The present concept uses steam and does not copy its needle-valve mechanism.
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