Currently I'm working on DIY bunsen burners, which lays the basic foundations for all mantle gas lamps. Because Carl Welsbach (gas mantle inventor) is one of the student of Heidelberg professor Dr. Bunsen (The one who is credited for the bunsen burner) I've found something very mystical about all pressure lamp, whether it uses natural gas, propane, butane, gasoline, kerosene, alcohol etc, they all have a tiny jet nozzle. The lanterns works on this principle are Petromax, Tilley, anchor, coleman, campingaz, primus etc. It seems that the gasified fuel exits through the tiny jet nozzle holes with some large air holes that can draw air into the tube and mix the fuel with the air to achieve a beautiful bunsen blue flame. If you cover the air hole of any burner, the flame becomes yellow immediately. The magical jet nozzle in nearly all pressure lamps of low power has a nozzle diameter of 0.1-0.2mm. The jet nozzle can be found on any gas working appliance which uses gas i.e. gas stove (if you lift the stove cover up) boiler etc. Why a jet nozzle has to have a specific size and diameter in order for the gas appliance to work correctly, if you change a jet with a large hole, the blue flame have some yellow tinge, if the jet hole too small, the flame smaller and more difficult to hold tight on the burner head as well as the colour of the flame becomes a deeper blue.
I miss the questions and did you read the book of friend A. Kaim about blue flame burners and their history.
@WimVe The question is, I think, in the quote above: Why [does] a jet nozzle… @Bunsen_Blue In pressure lamps the blueness is a result of correct mixing of vapourised fuel and air. Too much fuel leads to not enough air to combust the fuel, leading to yellow flame. This, too, is both effected and affected by fuel type. Higher energy-content fuel such as kerosene requires a smaller jet (orifice) than lower energy fuel (gasoline); and alcohol, being of lower energy requires a larger jet, still. Jet size will also affect light output. The other factors that will come into play are pressure, and design of the mixing chamber (which governs air/fuel mixing). At some point of orifice size, pressure, fuel, orifice size, and burner design will combine to result in poor mixing of fuel. Note: pressure stoves also work on the same principle — producing pure flame, not superheated gas inside a mantle producing light. Wim has given you a source to study. Original patents also provide explanation. Another good, but hard to get reference, is that of Herman Lahde: Cheers Tony
Where can you find this book? Is it very good? seems that imperial lighting sells this book for $44, I can't find it in any large library in my area.
@Bunsen_Blue The book is technical and very detailed. It’s not a relaxing Sunday morning read. Mine was a gift, so I don’t know where to get it except the seller you’ve mentioned. As it was originally privately published, I doubt it will be in a library. Tony
In essence, as what Tony mentioned. Many parameters and governing principles come into play together. The size of the jet orifice determines the cross-sectional area of that particular point of the gas flow path. The blue, non-luminous flame of Bunsen burners indicates complete burning reaction between the fuel and atmospheric oxygen. The reaction completes within the flame itself. Otherwise, you'd notice the yellow incandescence on the flame. To result a pale blue flame, you need to ensure the burner apparatus construction has the following basic requirements:- - the jet orifice size should be selected to be within the pre-calculated range to allow the right quantity of gaseous fuel through it during operation. (assuming the pressure range of the fuel supply is known). You need to know the mass flowrate of the gas. The amount of energy released from a complete combustion is proportional to the mass flow rate as well as the specific energy of the fuel. - the construction should allow sufficient atmospheric air to be introduced so that the right amount(mass) of oxygen could be secured for a known stoichiometric reaction between the fuel and oxygen. - the construction must have a mixing chamber or tube of appropriate length or size to allow intimate mixing of the fuel and air particles prior to combustion point. This is not as simple as it sounds. You must have the right fuel-air mix velocity so that flashbacks do not occur. Too high, the flame lifts off. Too low, combustion occurs in the mixing tube. You need the flame at the right position as well to get the highest temperature and the desired reaction. If the fuel-oxygen particles could not be brought intimately before combustion point, then the burning reaction might not be completed within the flame but perhaps, near the far-end/tip of the flame with the aid of supplemental air from the surroundings. This would allow oxygen-starved carbon in the fuel to be heated to incandescence in the flame and hence a yellowish hue. This applies for all naturally-aspirated burners including those deployed in most, if not all the pressure lamps and stoves. We have mostly remembered the Bunsen burner and also the Bernoulli principle since school days. However, some of the naturally-aspirated burners found on some lanterns and stoves have been closer to another development besides the basic Bunsen. Example, if you take a closer examination on the Teclu burner, you'd find that the setup is constructed with a bell-like air inlet and the amount of air could be varied by adjusting the distance between the jet and the mixing chamber/tube. It also allows the flame's location to be varied. In a way, it was sort of a refinement of the basic Bunsen burner. A lot pressure lamps and stoves also combined the workings with the Meker burner, having a form of wire gauze of mesh at the burner end to obtain multiple flamelets instead of a single large flame. In addition to preventing flashbacks, the burning is also more quiet.
