Injection gas burner low pressure according to the principle of organizing the mixing of gas with air, it refers to gas burners with partial pre-mixing.
The gas stream in the burner under pressure comes out of the nozzle (1) at high speed and, due to its energy, captures air in the confuser (2), drawing it inside the burner. Mixing of gas with air occurs in a mixer consisting of a confuser (2), a neck (3) and a diffuser (4). The vacuum created by the injector increases with increasing gas pressure in the burner, and at the same time the amount of sucked in primary air (from 30 to 70%) required for complete combustion of the gas changes. The amount of air entering the gas burner can be changed using the primary air regulator (6), which is a washer rotating on a thread. When the regulator is rotated, the distance between the washer and the confuser changes, and thus the air supply is regulated.
Low pressure injection gas burner:
1 - nozzle; 2 - confuser; 3 - neck; 4 - diffuser; 5 - fire nozzle; 6 - primary air regulator.
To ensure complete combustion of fuel in a gas burner, part of the air is supplied due to vacuum in the firebox. The secondary air flow rate is regulated by changing the vacuum in the furnace.
Low pressure injection burners are made with fire nozzles (5) of different shapes.
Injection gas-burners have the property of self-regulation, i.e. the ability to ensure a constant ratio between the amount of gas entering the burner and the amount of primary air sucked in by them. Moreover, if the air supply to the burner using a washer is adjusted according to the color of the flame or the gas analyzer reading for complete combustion of gas and the gas burner operates quietly without noise, then further changes in its load can be carried out by increasing or decreasing only the gas flow rate, without changing the position of the air washer .
When changing the operating mode of a gas burner, it is necessary to monitor the stability of its flame, since the nature of gas combustion is affected not only by the amount of primary air supplied to it, but also by the amount of secondary air entering the firebox.
The medium-pressure injection burner IGK designed by F.F. Kazantsev is a burner with complete pre-mixing and operates stably at a gas pressure of 2... 60 kPa (200... 6,000 mm water column).
The gas entering the gas burner through the gas nozzle (4) injects air in the amount required for combustion. In the mixer (2), consisting of a confuser, a neck and a diffuser, the gas and air are completely mixed.
Medium pressure IGK injection burner designed by F. F. Kazantsev:
1 - plate combustion stabilizer; 2 - mixer; 3 - air supply regulator; 4 - gas nozzle; 5 - staring contest.
At the end of the diffuser, a plate stabilizer (1) is installed in the gas burner, which ensures stable work burners without flame separation or flashover over a wide load range. The combustion stabilizer consists of thin steel plates located at a distance of approximately 1.5 mm from one another. The stabilizer plates are pulled together by steel rods, which, in the path of the gas-air mixture, create a zone of reverse currents of hot combustion products, due to the heat of which the gas-air mixture is continuously ignited. The flame front is kept at a certain distance from the burner mouth.
The air supply is regulated using the regulator (3). Sound-absorbing material is reinforced with glue on its inner surface. The regulator has an inspection window (5) to monitor the integrity of the stabilizer.
The disadvantages of injection burners include:
- significant dimensions of the burners along the length, especially burners with increased productivity (for example, the IGK-250-00 burner with a nominal productivity of 135 m3/h has a length of 1,914 mm);
- high noise level for medium-pressure injection burners when a gas jet flows out and air is injected;
- dependence of the supply of secondary air on the vacuum in the furnace (for low-pressure injection burners), bad conditions mixture formation in the furnace, leading to the need to increase the total excess air coefficient to 1.3...1.5 and even higher to ensure complete combustion of the fuel.
Osm 19-06-2007 07:45
Hello, dear ones.
I assembled an injection burner to make a small gas forge, but I can’t get it to reach normal temperatures.
I can't pick it up optimal parameters because I don’t understand the principle of operation.
For example - how does the diameter of the nozzle affect, how does the diameter of the nozzle opening affect, how does pressure affect?
Previously, everything worked for me from a frog reducer, there was clearly not enough pressure and the flame was yellow, now I use a special propane reducer with adjustable pressure, I managed to get a flame of blue color. I tried to work with the blast from a vacuum cleaner, but it blew out the fire.
Please explain the principle of operation.
Mutant 19-06-2007 13:18
Hmm, it's not that simple...
The injector nozzle produces a stream of gas or vapor, which sucks in air (preferably oxygen) and at the same time mixes with it. And the quality of the resulting mixture depends on the flow rate (roughly - on pressure), the diameter of the nozzle and the size of the chamber. Then this mixture goes directly to the burner.
The amount of air in the mixture is regulated either by pressure (with forced supply) or by shutting off the special. windows in the cell.
Fuel - needle valve.
The simplest example is blowtorch. The air intake is not regulated in any way, the power is controlled by fuel pressure.
Usually, the higher the pressure, the louder the noise, the better the mixing, the better the heat.
Pressure - the more, the better (within reasonable limits), it is easier to regulate. And the diameter of the injector nozzle depends on the available pressure - the lower the pressure, the larger diameter. Yes, the diameter also depends on the heating power that needs to be obtained (0.1 - 0.15 for jewelry burners, 0.3 - 0.5 for soldering irons). I selected it experimentally.
A yellow sluggish torch means a lot of fuel, a torch comes off - not enough, a blue transparent one - just that.
Yes, so that the torch does not come off, they install a divider that slows down the flow, and add an additional ignition torch.
Osm 19-06-2007 13:29
Thanks for the answer, I didn’t quite understand how the nozzle diameter is 0.1-0.5, what units are these, or did you mean the nozzle diameter?
And also about the diameter of the mold - if I reduce the diameter of the nozzle, with a constant output pressure on the reducer, then the gas flow rate increases, does this have a positive effect on air leakage or not?
Mutant 19-06-2007 14:48
quote: nozzle diameter - 0.1-0.5, what units are these,
quote: I reduce the diameter of the nozzle, with a constant output pressure on the reducer, the gas flow rate increases,
Why will the flow rate increase if the pressure is the same?
If you need to increase the air content, then enlarge the windows, play with the size of the chamber.
If it doesn't help, reduce the diameter of the injector.
Or increase the pressure.
By the way, heating (due to heat transfer from the torch) can change modes (air leakage is reduced), it is better to have a reserve.
Osm 25-06-2007 08:33
Yesterday I finally got a normal result from the burner, it turned out that my pressure was too low. I noticed an interesting effect - when the pressure increases, you need to close the air damper, otherwise it burns unstable.
Now I want to ask.
Tell me, what is the diameter of the nozzle and what is the pressure, I want to understand whether it is normal or not, that with a diameter of 1 mm, the pressure is 2 kgf/cm2?
50mk76 25-06-2007 10:59
My first mistake was placing the air choke too close to the injector. The burner is hungry for air and pressurization is required. A closely located damper did not allow the formation of a normal gas mixture. The burner was started with the damper almost closed, and when completely open it knocked out the flame. I had to constantly adjust. Now I have widened the distance between the nozzle and the damper. It has become much better, but now we need to increase the fan power. The photo is old. Shown as it was.
Osm 25-06-2007 12:05
250mk76
Yes, I also have a damper at about the same distance. Tell me, what is your blood pressure now? The nozzle diameter, as I understand it, is 0.75mm.
Can you show me a photo of what it is like now?
Also, how do you determine that there is not enough air?
50mk76 25-06-2007 13:36
There is no final photo. I recorded all my experiments. The stove is only today's. Nozzle 200 mm. diameter 32 mm. The rest is all 40 mm pipe. Barrels 110 mm long. The flame should be even with a bluish tint. I always play with the reducer and damper to achieve the required temperature. On large workpieces the damper is fully open, on the gearbox 1.5-2 atm. When the oven warms up, I reduce it to 1-1.2 atm. I save gas. I close the entrance to the oven with a brick but leave a small gap. Try starting the stove, let it warm up for about 10 minutes with the entrance covered. The bricks should be red inside. Then experiment with pressure, nozzle, damper, etc. Mind you, as you can see, all the connections are threaded and easier to modulate.
Osm 25-06-2007 16:17
Tell me, what is the maximum pressure in the home gas network?
Kuzya 25-06-2007 21:23
Network pressure is approximately 300-400 mm.
I can’t say for sure, because I don’t deal with household items.
For natural gas, the nozzle should be slightly different
The gas-air ratio is selected for each system.
If the flame is straw-colored and there is black smoke (not smoke, but smoke, you can see it if you put a sheet of paper), then there is not enough oxygen.
If the torch comes off, there is correspondingly a lot of air.
Flame, in ideal conditions should be bright blue (for natural gas), or with yellow tongues(for cylinders with a propane-butane mixture, as in the picture).
Gas-air adjustment is done only on a warmed-up unit; for such sizes, 10-15 minutes should be enough.
It is better if air leaks around the perimeter are completely removed. Leaks create local fluctuations in the firebox and can simply tear the lining. Coat the firebox with chamotte, which will help avoid the problem of adding tinctures every time.
Question for everyone.
I don’t understand a little why the pressure is 1-2 kg?
The point of all this?
At work gas boiler it is up to 400 mm, and heats not three centimeters of area.
A vacuum cleaner is loud and unaesthetic for an ordinary box with a fan for 100-200 rubles per eye, for such a living thing.
It might be better to try to twist the flow by increasing the length of the torch or making a ring or hearth burner. For such a system it is IMHO better.
But since you want injection, try breaking the air flow to the burner, or tighten it. By stopping and adding oxygen to the combustion area.
Osm 26-06-2007 06:48
What is a ring or hearth burner, I looked it up in Yandex, but all of them are some kind of industrial devices, you can sketch them out schematic diagram? It might actually be easier to do as you say.
I don't understand from your drawing where the nozzle is? How do the blades bend? How does the air flow rotate? Where does the gas burn and mix with air? Please explain, the topic is very interesting.
Kuzya 26-06-2007 21:55
I won't fool you.
You can take any book on heating engineering and read about hearth and ring burners.
Don't be offended, it's just the 4th year of the institute and two semesters of lectures
You wrote that there is already a burner, draw, at least schematically, what it looks like. Already ready product It’s easier to optimize for combustion than to make a new one.
Most likely you will not be able to form a torch, i.e. no embrasure.
Draw, I’ll try to help with advice.
I couldn’t find any guides for the burners, no drawings or photos. Damn, apparently such a terrible secret
I found something similar, only with holes, and a gap on the burner guides
Oleg79 26-06-2007 22:38
quote: Originally posted by Kuzya:
I found something similar, only with holes
This picture reminds me a lot of a detail from electric juicer
Kuzya 26-06-2007 22:51
She is
Well, the view is the same.
Mutant 27-06-2007 08:26
For some reason I didn’t quite understand which burner was needed - a stationary one or a manual one.
Nowadays, it’s probably easier to buy a ready-made product than to invent it yourself... There are also micro and macro jewelry on sale, which are used to heat the roofing material. But if you’re interested in figuring it out, that’s also a good thing...
Here is an old publication in M-K: Yu. Orlov. Universal burner (Model designer) File size: 55.55 Kb http://mail.mega.dp.ua/mche/modules.php?name=Downloads&d_op=getit&lid=1368
If you're interested, I can take a photo of my burners.
Osm 27-06-2007 08:39
2Mutant
In general, initially I needed to make a burner for a small gas forge, in principle this has already been done, but I can’t really set it up. The burner is powered by a gas cylinder. All I did was copy it from existing articles, without really understanding the principles of work. Now I want to figure out how mine works and perhaps learn something new - for example, how to make a burner that operates at low pressure from the home gas network.
It would be very interesting to see photos of the burners you have.
Osm 27-06-2007 13:47
2kuzya
Browsed the books:
Thermal engineering, edited by Baskakov.
Heat engineering, Chechetkin, Zanemonets
Thermal engineering, edited by Krutov.
I didn’t see any mention of the terms ring and hearth burners, although I did find something about injection burners.
Could you recommend relevant literature (preferably, the one that can be found on the internet).
Kuzya 28-06-2007 23:21
I apologize for not answering right away.
I took away from the heating engineers the book “Combustion of gases in the furnaces of boilers and furnaces and maintenance of the gas facilities of enterprises” by V.M. Chepel, I.A. Shur.
You can probably search on the Internet, but it is specifically for the personnel responsible for the gas industry.
In general, I scanned the gas burners, but it turned out to be 51 sheets and 5 Mb.
If it suits you, here is the link http://ig-79-9t.narod.ru/gorelki.rar
If on a dialup, then tell me how to distill it into .pdf to compress it.
I clarified that in the city network the pressure is 120 mm, which is not enough for normal power.
When looking at injection burners, pay attention to:
- your burner does not have an element forming a torch, and the shape is the opposite of the “original”,
- by sticking the gas line in this way, you force the air flow to bend around it, and when there is still little air, the vacuum behind the tube at the nozzle tears off the torch.
In general, read, look, if anything is not clear, ask
Osm 29-06-2007 06:37
ok thanks, I'm reading
Grinya 29-06-2007 10:04
maybe this will be useful,
It used to be both here and there.
Quite a cool book with a scientific bent, although overall nothing particularly complicated. Truth in English
http://rapidshare.de/files/17385588/Industrial_Burners_Handbook_-_C.E.Baukal__2003_.rar
http://mmcd.meditprofi.ru/machining/Industrial_Burners_Handbook_-_C.E.Baukal__2003_.rar
Vlad Klem 02-07-2007 15:28
That Osm
In their responses to you, the participants got everything mixed up. Sour and hard, hot and sweet. The advice includes jewelry burners and asphalt heating burners, which only work on outdoors, since the afterburning of the torch is due to atmospheric air. Try sticking the nozzle of this burner into closed space and it will go out instantly. I posted to you drawings of injection burners taken from the websites of American blacksmiths and metallurgists. (All the dimensions are there, though in inches, but I think it’s not a problem to convert it to mm). Burners are designed for thermal power and, depending on the gas pressure, the diameter of the nozzle hole, (approximately from 0.5 to 1.0 mm) the diameter and length of the mixing tube (approximately 1/2" to 1") and the diameter of the air (air) holes for ejected air. I will say that a bottled propane-butane mixture supplied under a pressure of 3 at. with an excess air coefficient of 1.1 it gives a flame temperature of up to 2100*C.
Next, an injection burner using network gas will not work. You need forced air injection and a mixing chamber. This is roughly the diagram:
Osm 02-07-2007 15:33
2mutant
oh thank you, that's informative.
Osm 02-07-2007 15:42
2Vlad Klem
Thanks for the comment, I’m already reading books and it seems like I’m able to understand the essence and separate the hot from the sweet. I really came across the fact that the burner works well in the open air and goes out in the stove, I understand why.
Regarding network gas - I’ve already seen such a scheme, but there are doubts that there will be enough network gas to provide required amount heat per unit time, commensurate with what an injection burner gives and a pressure of 2-3 atm. I don’t think it will be possible to significantly increase thermal insulation, i.e. The stove will take longer to heat up than it takes to cool down. What is your opinion?
Kuzya 02-07-2007 17:53
2 Vlad Klem:
I don’t know how it is with the blacksmiths in Pendosia
And our injection burners are divided into two types:
1. with gas-air injection
2. with air gas injection
For burners of the second type, operating at a pressure of 350-500 mm (medium pressure), a fan is not needed, which is the main advantage of the design. Moreover, at medium pressure the torch is quite short.
Vlad Klem 02-07-2007 20:32
That Osm
Network gas mainly consists of methane. His calorific value lower than that of a propane-butane mixture. I don’t know what the pressure is in household wiring, but I know that with an excess air coefficient of 1.2-1.25, the flame temperature will not be lower than 1800*C. So it’s quite enough for a stove, even for melting steel, only the burner design will be different and the jet hole will be different (larger). You just need to calculate what it will be at the pressure of the household network. The most important thing for any stove is thermal insulation.
That's Kuzya
I don’t know how it is with the blacksmiths in Pindosia,
but here in Moscow on Nagornaya it is done as I wrote. And what’s interesting is that it works well.
And if you deign to bring up my old posts, you will read where I once already noted that some of our knife makers, for example G.K., have been using burners made by me for several years now. Prokopenkov and Vasily Kozlov and, of course, Alexey Kukin. And also Sergey Danilov (Samurai) and Igor Pampukha. And some others who, with my permission, made them themselves.
Kuzya 03-07-2007 04:02
quote: Originally posted by Vlad Klem:
With my permission, they made them themselves.
Holy crap!!!
And I was wondering who in RUSSIA develops burners.
I laugh because my grandfather taught, and my father installed and adjusted burners for 30 years, and this is not the first year that I have been working with my father. BIG Promenergogazovsky - the works not only of ours, but also of a huge team that works throughout the country.
And if you are trying to challenge your opinion, you need arguments and not data “from the air”, and throw Pindos arguments here.
This is something to think about.
Alhim 31-08-2007 01:43
I recently made a stove, using it as fuel (because, as a poor student, I can’t afford to spend such quantities of propane). It warms up just fine, it just makes a lot of noise (it looks like it’s about to take off). If you want, I can send you photos. The question is determining the temperature of the workpiece - against the background of heated bricks (the flame is almost transparent), I cannot determine the color of the workpiece. I tried to harden two blades from X12MF - both melted, did not burn (because they were under flux), but melted (when the flux was removed, you could see the marks from the emery turning into the melted surface along a clear curved line) and this with a light yellow (to look) color heat. Experienced people, if it’s not difficult, make a sign with flowers (a picture of a square of the required color - the temperature that corresponds in your opinion).
Osm 03-09-2007 17:56
2Alhim
Of course, it would be very interesting to see pictures.
Osm 04-09-2007 18:05
Is there any formula for calculating gas flow at the exit of a nozzle of a certain diameter, if it is supplied to the nozzle under a certain pressure? Or is this also affected by the geometry of the nozzle, the diameters of the supply hoses, etc.? It is the gas consumption that is of interest, and not the amount of the resulting combustible mixture.
Osm 04-09-2007 18:06
Addition - I think that the gas is released into the atmosphere, i.e. outside pressure is atmospheric.
Alhim 04-09-2007 18:34
quote: Originally posted by Osm:
I read smart books. I understood a lot.
I came up with a question that I couldn't find an answer to:
Is there some kind of formula for calculating gas flow when exiting a nozzle of a certain diameter....... Or is this also influenced by the geometry of the nozzle, the diameters of the supply hoses, etc.? It is the gas consumption that is of interest, and not the amount of the resulting combustible mixture.
Everything is affected by the hoses and (especially) the geometry of the nozzle and the injector nozzle. But how to calculate all this is the question. I’ll post photos of the stove in the near future (as soon as I bring someone with a camera to it).
Grinya 05-09-2007 07:16
Alhim, you are writing a lie.
Osm, please clarify what you mean by “supplied to the nozzle under a certain pressure.” The pressure immediately before the tapering part of the nozzle, or at the exit from the cylinder, and after it through the pipeline, and only then the prechamber.
In any case, the influence of the hoses only affects the pressure drop in them.
Gas flow [kg/(m**2 sec)] does not depend on the nozzle configuration, only on the pressure and temperature of the gas directly in front of the nozzle, and the scale is clear. BUT if you want to get a normal jet with a pressure ratio Pforchamber/Patm>1.89, then you need to correctly profile the expanding part, and here a lot depends on the pressure and the desired results.
R.S. in the book in English that I referred to it is,
in Russian it is in any textbook on gas dynamics. Chapter acceleration of gas flow.
Osm 05-09-2007 11:28
2Grinya
I meant the pressure at the outlet of the reducer, after the reducer there is a hose to the nozzle.
Only I don't quite understand. If I put a barometer on the nozzle, will it show a pressure different from what the reducer shows?
There is no talk about the jet. I just want to understand what gas flow rate an injection burner has with certain parameters (I know the diameter of the nozzle and the pressure of the supplied gas.) and select the diameter of the nozzle so that at a pressure equal to the pressure in the household network, the flow rate is the same, then supplying the required amount of air I I'll get a burner of similar power.
Grinya 05-09-2007 11:44
Of course, there is a pressure drop across the hose, as with any resistance.
What is your pressure, more than 0.89 excess atmospheres?
critical section flow
q=P/sqrt(T)*((2/k+1)**(k+1/2(k-1)))*sqrt(k/R) [kg/m**2 sec]
P,T-total pressure in pascals and temperature in kelvins in front of the nozzle
sqrt-square root
k-adiabatic exponent
**- exponentiation
R-gas constant in Si (kg and not moles)
Osm 05-09-2007 13:17
2Grinya
excess pressure in the household network, as I understand it, is 13 mbar.
I didn’t understand about the formula, i.e. Is there no dependence on the nozzle diameter at all?
Grinya 05-09-2007 14:04
I wrote the dimension, kg/m**2 sec, multiply by the nozzle area and get kg/sec.
Alhim 05-09-2007 14:15
Hmm, for some reason I thought that the flow rate through the nozzle depends on its geometry. Grinya, could you tell me how to calculate the injector. Given - the diameter of the gas nozzle is 1 mm, the pressure at the entrance to the nozzle is 4 ati, the diameter of the injector pipe is 40 mm, the length is 100 mm. The question is how much air is injected?
Osm 05-09-2007 15:45
So, nothing can be said about the amount of injected air; as I understand it, this is the subject of designing a specific burner.
Grinya 06-09-2007 08:11
quote: So, nothing can be said about the amount of injected air; this, as I understand it, is the subject of designing a specific burner.
That’s right, you can try to scale it using an already known burner.
The pipe area is proportional to fuel consumption (at first glance), the pipe length is 5-7 diameters (from the book ratio).
There are actually 2 questions here, so that as much as necessary is sucked in, taking into account the efficiency (diameter), and so that all this is fictitiously mixed, i.e. the diameter of the mixing layer = the diameter of the pipe => the length of the pipe.
if the second one hasn’t gone anywhere yet, then I have no idea what to do with the first one.
It’s easier not to worry about it, but to do it according to ready-made drawings
Grinya 06-09-2007 13:05
We are looking for books together.
V.P. Mikheev
Gas fuel and its combustion
subsoil 1966
V.V. Murzakov
Fundamentals of the theory and practice of gas combustion in steam boilers
Energy 1964
Ivanov Yu.V.
Basics of calculation and design of gas burners.
I think the key words are clear.
I don’t have a scanner, it’s too clumsy to interrupt
Osm 06-09-2007 16:27
ok, sanks.
Alhim 07-09-2007 01:12
But you didn’t understand - there is a burner and it works normally (I’ll post a photo one of these days - sorry for the delay, I’m sick right now), but it’s just not clear what kind of atmosphere is created in the stove during operation - oxidizing or reducing.
tov. Gnom 09-09-2007 18:32
Tell me, what is the average burner consumption? And how long does it take for a workpiece of about 5 mm to warm up?
Osm 18-09-2007 10:24
The first photo is of the oven during operation, running at full power (the snail is on).
Secondly, the top of the furnace shows the burner body, the top of the burner stone, the fan and the nozzle.
Third - well, this is, in fact, the ingot that came out of this smelting (about 1.7-2% carbon, due to rapid cooling, voids were created inside, it was not possible to unchain it, it burst.
Fourth - the burner cover is removed, the burner stone is visible.
Fifth - the burner cover itself with the injector, you can see the pilot hole in the burner stone.
Osm 27-09-2007 06:30
Thanks a lot.
Please tell me, it turns out that you have oil under pressure and air coming to your injector, but why do you also need a volute? Does it create a vacuum in the burner stone or for better mixing of the mixture?
Alhim 27-09-2007 15:28
The snail is needed to supply additional air. It enters the burner body tangentially and swirls the flow, and also to cool the injector.
Burners in which the formation of a gas-air mixture occurs due to the energy of a gas stream are called injection. The main element of an injection burner is the injector, which sucks air from the surrounding space into the burners.
Depending on the amount of injected air, burners can be with incomplete air injection and with complete pre-mixing of gas with air.
Burners with incomplete air injection. Only part of the air necessary for combustion enters the combustion front; the rest of the air comes from the surrounding space. Such burners operate at low gas pressure. They are called low-pressure injection burners (Fig. 3, a).
The main parts of injection burners are the primary air regulator, nozzle, mixer and manifold (see Fig. 3).
Rice. 3. Injection atmospheric gas burners:
a - low pressure; b - burner for a cast iron boiler; 1 - nozzle; 2 - injector; 3 - confuser; 4 - diffuser; 5 - collector; 6 - holes; 7 - primary air regulator
The primary air regulator 7 is a rotating disk or washer and regulates the amount of primary air entering the burner. Nozzle 1 serves to convert the potential energy of gas pressure into kinetic energy, i.e., to give the gas stream such a speed that provides suction required air. The burner mixer consists of three parts: injector, confuser and diffuser. Injector 2 creates a vacuum and air leaks. The narrowest part of the mixer is confuser 3, which levels the stream of the gas-air mixture. In diffuser 4, final mixing of the gas-air mixture and an increase in its pressure occurs due to a decrease in speed.
From the diffuser, the gas-air mixture enters the manifold 5, which distributes it among the holes 6. The shape of the manifold and the location of the holes depend on the type of burners and their purpose.
Burner distribution manifold DHW water heaters has the shape of a circle; at the burners instantaneous water heaters the collector consists of parallel tubes; for units with an elongated firebox, the manifold is elongated; burners for a cast iron boiler (Fig. 3, b) have a rectangular collector with a large number of small holes.
Low pressure injection burners have a range of positive qualities, thanks to which they are used in household gas appliances, as well as in gas appliances for enterprises Catering and other municipal gas consumers. Injection burners are also used in cast iron heating boilers.
The main advantages of low-pressure injection burners: simplicity of design, stable operation of burners when loads change; reliability and ease of maintenance; quiet operation; possibility of complete combustion of gas and operation at low gas pressures; lack of pressurized air supply.
Important characteristic incomplete mixing injection burners - injection coefficient - the ratio of the volume of injected air to the volume of air required for complete combustion of the gas. So, if 10 m3 of air is needed for complete combustion of 1 m3 of gas, and the primary air is 4 m3, then the injection coefficient is 4: 10 = 0.4.
A characteristic of burners is also the injection ratio - the ratio of primary air to burner gas flow. In this case, when 4 m3 of air is injected per 1 m3 of burned gas, the injection ratio is 4.
The advantage of injection burners is their self-regulating property, i.e. maintaining a constant proportion between the amount of gas supplied to the burner and the amount of injected air when constant pressure gas
The limits of stable operation of injection burners are limited by the possibilities of flame separation and breakthrough. This means that it is possible to increase or decrease the gas pressure in front of the burner only within certain limits.
Burners with complete pre-mixing of gas and air. The injection of all the air required for complete combustion of the gas is ensured by increased gas pressure. Full gas mixing burners operate in the pressure range from 5000 Pa to 0.5 MPa. They are called medium pressure injection burners and are used mainly in heating boilers and for heating industrial furnaces. The thermal power of burners usually does not exceed 2 MW. The main difficulties in increasing their power are the difficulty of combating flame breakthrough and the bulkiness of the mixers.
These burners produce a low-luminous torch, which reduces the amount of radiation heat transferred to heated surfaces. To increase the amount of radiation heat, it is effective to use it in the furnaces of boilers and furnaces. solids, which perceive heat from combustion products and radiate it to heat-receiving surfaces. These bodies are called secondary emitters. Fireproof walls of tunnels, walls of furnaces, as well as special perforated partitions installed in the path of movement of combustion products are used as secondary emitters.
Burners with complete pre-mixing of gas and air are divided into two types: with metal stabilizers and refractory nozzles.
The injection burner designed by Kazantsev (IGK) consists of a primary air regulator, a nozzle, a confuser, a mixer, a nozzle and a plate stabilizer (Fig. 4).
Rice. 4. IGK injection burner:
1 - stabilizer; 2 - nozzles; 3 - confuser; 4 - nozzle; 5 - primary air regulator
The primary air regulator 5 of the burner simultaneously functions as a noise muffler, which is created due to the increased speeds of the gas-air mixture. Plate stabilizer and flame breakthrough in a wide range 7 ensures stable operation of the burner without flame separation or breakthrough in a wide range of loads. The stabilizer consists of steel plates 0.5 mm thick with a distance between them of 1.5 mm. The stabilizer plates are pulled together by steel rods, which create a zone of reverse flows of hot combustion products along the path of the gas-air mixture and continuously ignite the gas-air mixture.
In burners with fireproof nozzles natural gas burns with the formation of a low-luminous flame. In this regard, the transfer of heat by radiation from the burning gas torch is insufficient. IN modern designs gas burners have significantly increased the efficiency of gas use. The low luminosity of the gas plume is compensated by the radiation of hot refractory materials when burning gas using the flameless combustion method.
The gas-air mixture in these burners is prepared with a slight excess of air and enters hot refractory channels, where it heats up intensively and burns. The flame does not come out of the channel, therefore this gas combustion process is called flameless. This name is conditional, since there is a flame in the channels.
The gas-air mixture is heated from the hot walls of the channel. In places where channels expand and near poorly bluffed bodies, retention zones of hot combustion products are created. Such zones are stable sources of constant heating and ignition of the gas-air mixture. In Fig. Figure 5 shows a flameless panel burner. The gas entering the nozzle 5 from the gas pipeline 7 injects the required amount of air, regulated by the primary air regulator 6. The resulting gas-air mixture through the injector 4 enters the distribution chamber 3, passes through the nipples 2 and enters the ceramic tunnels 1. In these tunnels, the gas-air mixture is burned. The distribution chamber 3 from the ceramic prisms 8 is thermally insulated with a layer of diatomaceous earth, which reduces heat removal from the reaction zone.
Flameless combustion of gas has the following advantages: complete combustion of gas; possibility of gas combustion with small excess air; opportunity to achieve high temperatures combustion; combustion of gas with high thermal stress of combustion volume; transfer of a significant amount of heat by infrared rays.
Based on the design of their fire part, existing designs of flameless burners with refractory nozzles are divided into burners with nozzles having channels of irregular geometric shape; burners with nozzles having channels of regular geometric shape; burners in which the flame is stabilized on the fireproof surfaces of the firebox.
Rice. 5. Flameless panel burner:
1 - tunnel; 2 - nipple; 3 - distribution chamber; 4 - injector; 5 - nozzle; 6 - air regulator; 7 - gas pipeline; 8 - ceramic prisms
The most common are burners with nozzles of regular geometric shape. The refractory nozzles of such burners consist of ceramic tiles measuring 65 x 45 x 12 mm. Flameless burners are also called infrared burners.
All bodies are sources of thermal radiation arising due to the vibrational motion of atoms. During radiation, the thermal energy of substances is converted into the energy of electromagnetic waves, which propagate from the source at a speed equal to the speed of light. These electromagnetic waves, spreading in the surrounding space, collide with various objects and easily turn into thermal energy. Its value depends on the temperature of the radiating bodies. Each temperature corresponds to a certain range of wavelengths emitted by the body. In this case, heat transfer by radiation occurs in the infrared region of the spectrum, and burners operating on this principle are called infrared burners (Fig. 6).
Through nozzle 4 (see Fig. 6, a) the gas enters the burner and injects all the air necessary for complete combustion of the gas. From the burner, the gas-air mixture enters the collection chamber 6 and is then directed into the fire holes of the ceramic tile 2. To avoid flame breakthrough, the diameter of the fire holes must be less than a critical value and be 1.5 mm. The gas-air mixture leaving the fire chambers is ignited at a low speed of its exit in order to avoid flame separation. In the future, the rate of exit of the gas-air mixture can be increased (open the tap completely), since the ceramic tiles heat up to 1000°C and give up some of the heat to the gas-air mixture, which leads to an increase in the speed of flame propagation and the prevention of its separation.
Rice. 6. Infrared burners:
a - burner diagram: 1 - reflector; 2 - ceramic tile; 3 - mixer; 4 - nozzle; 5 - body; 6 - collection chamber; b, c and d - burners GII-1, GII-8 and PS-1-38, respectively
Ceramic tiles have about 600 cylindrical fire channels, which makes up about 40% of the surface of the tiles.
The tiles are connected to each other with a special putty consisting of a mixture of fireclay powder and cement.
If infrared burners operate on medium pressure gas, then special plates made of porous heat-resistant materials are used. Instead of cylindrical channels, they have narrow curved channels that end in expanding combustion chambers.
When gas is burned in numerous channels of various nozzles, their outer surfaces are heated to a temperature of about 1000 °C. As a result, surfaces acquire an orange-red color and become sources of infrared rays, which are absorbed by various objects and cause them to heat up.
In Fig. 6, b... d shows the most common types of infrared burners. GII-1 burners have 21 ceramic tiles, a reflector and junction box. Using GII burners you can heat rooms and various equipment. Burners are also used to heat open areas ( sports grounds, cafes, summer premises, etc.).
The GK-1-38 burner is successfully used for heating walls and plaster under construction, heating people working in winter conditions. The burner can operate on natural and liquefied gases.
A welding gas torch is a specialized design in which flammable gas or vapors of a special liquid are mixed with oxygen from environment. Thanks to this, a stable welding flame of the required power occurs. In principle, it is generally accepted that this equipment is one of the main working tools of a gas welder.
There are quite a few types of welding torches. Despite the fact that the principle of their operation is approximately the same, they may have a number of features:
- Injector and non-injector designs - they differ from each other in the technology of supplying oxygen to the combustion area;
- Gas or liquid. In the former, a special flammable gas is used to obtain a flame of the required temperature, while the latter operate on gasoline or kerosene vapor;
- Specialized or universal, the latter can be used for any work related to cutting or welding metal;
- Single-flame and multi-flame are differentiated depending on the flow of the supplied flame;
- Machine and manual;
- Gas welding torches can be classified according to power: low, medium, high.
Operating principle of injectionless operation
If the welding torch operates at high pressure and has an injector, then its design will be much simpler compared to a design where the pressure is much lower. The technology of its operation is as follows:
- Oxygen enters it through special necks made of rubber, passing through the valve, and then is sent to the mixer;
- In the mixer, the entire flow is divided into many small jets and directed into the mixer nozzle. Using the same technology, it is sent to a special valve;
- The resulting mixture in MIG-MAG welding torches passes through a gas flow of a significant cross-section, where circulation ends, and at the exit it turns out to be the most homogeneous;
- On the tip tube there is a mouthpiece, which is made from durable, non-oxidizing copper. The mixture at the outlet will immediately burn completely, and the temperature will be quite high, which will be significantly higher compared to the melting point of the metal.
In order for a torch intended for gas welding, the gas flow must come out evenly at the most accurately adjusted speed, and the mixture must burn completely. If the gas exit velocity is small, then the flame can turn into top part burners - this is quite dangerous, since an explosion of this mixture often occurs inside the burner.
If the speed is too high, the flame will break away from the mouthpiece and move further and further from the cut, which will ultimately lead to its attenuation. To determine the required speed, it is necessary to take into account several important data: what the combustible mixture consists of, what is the internal diameter of the nozzle, how the mouthpiece is designed. It is possible to calculate the correct fuel supply rate only if all these data are known.
The average value is considered to be in the range from 70 to 160 m/s. In order to ultimately achieve a suitable output speed, it will be necessary to create a pressure of the order of 0.5 atmospheres, and the pressure for gas or vapor and oxygen will be approximately the same.
Injector burners
The design of the welding torch involves the use of acetylene, hydrogen or methane as fuel, and it is very easy to use. The operating principle is as follows: oxygen from the cylinder enters through a special valve, passing through the injector cone, and enters the mixing chamber. A flammable gas is pumped through the injector and intensively mixed with oxygen. After this, the formed mixture is sent through the tip tube into the mouthpiece. Thanks largely to oxygen, the pressure of the gas escaping from the mouthpiece nozzle becomes significantly less than atmospheric pressure.
However, for high-quality combustion and obtaining a normal temperature, it must be at least 3.5 atmospheres. It is worth noting that the injection burner has one very serious drawback: the composition of the combustible mixture remains variable, which does not allow for high-quality and constant combustion.
Despite the fact that this product operates at low pressures, it is used much more often than designs designed for high pressure. The structure of this product is somewhat more complicated, since it contains a special cooling unit for the welding torch. The fact is that low pressure causes quite strong heating of the nozzle and other elements. The main thing here is to prevent the chamber where the flammable mixture is formed from overheating and exploding.
Features of welding work using a gas torch
First of all, gas torches are distinguished by the fact that they are perfect for semi-automatic or automatic welding work, when the welding wire is fed without the use of hands, which greatly facilitates the technological process.
Thanks to automatic welding, you can qualitatively weld all hard-to-reach areas, and you will have to apply a minimum amount of effort. The amount of waste from such work is minimal. The weld seam is quite strong in a much shorter period of time than during electric arc welding. There are not too many disadvantages to this technology; they concern, first of all, quite high cost equipment and components. The entire system is complex in terms of design; the products are very heavy and bulky, so moving them from one place to another will be very problematic.
The welding process consists of the following stages:
- The areas of the parts to be welded must be thoroughly cleaned of all traces of rust or corrosion. You can do this using a special metal brush attached to an angle grinder.
- Be sure to degrease the surface using TIG or other compounds, otherwise the consumable electrode will not adhere too tightly to the metal;
- The gas burner is activated, the semi-automatic electrode supply mechanism is started and the direct work of connecting metal elements begins;
- Be sure to set the electrode feed speed. It depends on the type of metals being welded, their thickness and a number of other factors.
How to properly handle the burner?
Before you begin the actual work, you need to check how well the injection component of the equipment works. To do this, connect the oxygen reducer hose to the nipple that supplies oxygen. Carefully raise the pressure in the system to operating pressure.
When oxygen passes through the injector, a vacuum should occur in the acetylene channel. If it is, the finger will stick to the acetylene nipple. In this case, connect both hoses and carefully secure them; only after this can the combustible mixture be ignited and the flame size adjusted.
When finishing work, first close the valve of the acetylene cylinder, and then close the oxygen valve. If you do the opposite, a fire may strike the hose through which acetylene is supplied, which can lead to an explosion. If the work technology is followed, it will be possible to obtain a reliable connection that will retain its strength for a long time.
Low pressure injection gas burner
1
- nozzle, 2
- a confuser, 3
- neck, 4
- diffuser,
5
- fire nozzle, 6
- primary air regulator,
Principle of operation
A jet of gas in the burner under pressure comes out of nozzle 1 at high speed and, due to its energy, captures air in confuser 2, drawing it inside the burner. Mixing of gas with air occurs in a mixer consisting of a confuser 2, a neck 3 and a diffuser 4.
The vacuum created by the injector increases with increasing gas pressure in the burner. At the same time, the amount of sucked in primary air (from 30 to 70%) required for complete combustion of the gas changes.
Features of operation
The amount of air entering the gas burner can be changed using the primary air regulator 6, which is a washer rotating on a thread. When the regulator is rotated, the distance between the washer and the confuser changes and thus the air supply is regulated.
To ensure complete combustion of fuel in a gas burner, part of the air is supplied due to vacuum in the firebox. The secondary air flow rate is regulated by changing the vacuum in the furnace.
Injection gas burners have the property of self-regulation, i.e. the ability to ensure a constant ratio between the amount of gas entering the burner and the amount of primary air sucked in by them. Moreover, if the air supply to the burner using a washer is adjusted according to the color of the flame or the gas analyzer reading for complete combustion of gas and the gas burner operates quietly without noise, then further changes in its load can be carried out by increasing or decreasing only the gas flow rate, without changing the position of the air washer .
When changing the operating mode of a gas burner, it is necessary to monitor the stability of its flame, since the nature of gas combustion is affected not only by the amount of primary air supplied to it, but also by the amount of secondary air entering the firebox.
The IGK medium-pressure injection burner designed by Kazantsev is a burner with complete premixing.
Contact us to consult on price, availability and delivery conditions:
Medium pressure IGK injection burner designed by Kazantsev
1
- plate combustion stabilizer 2
- mixer
3
- air supply regulator 4
- gas nozzle 5
- staring contest
The gas entering the gas burner through the gas nozzle 4 injects air in the amount required for combustion. In mixer 2, consisting of a confuser, a neck and a diffuser, complete mixing of gas and air is carried out.
At the end of the diffuser, a plate stabilizer 1 is installed in the gas burner, which ensures stable operation of the burners without flame separation or flashover in a wide range of loads.
The combustion stabilizer consists of thin steel plates located at a distance of approximately 1.5 mm from one another. The stabilizer plates are pulled together by steel rods, which, in the path of the gas-air mixture, create a zone of reverse currents of hot combustion products, due to the heat of which the gas-air mixture is continuously ignited. The flame front is kept at a certain distance from the burner mouth.
The air supply is regulated using regulator 3. On its inner surface, noise-absorbing material is reinforced with glue. The regulator has an inspection window - peephole 5 - to monitor the integrity of the stabilizer.
Due to good mixing of gas with air, injection burners provide the creation of a low-luminosity torch with complete combustion of gas at low excess air ratios.
Advantages of injection burners:
- simplicity of design;
- stable operation of the burner when loads change;
- reliable operation and ease of maintenance;
- lack of a fan, an electric motor to drive it, or air ducts to the burners;
- the possibility of self-regulation, i.e. maintaining a constant gas-air ratio.
- significant dimensions of the burners along the length, especially burners with increased productivity (for example, the IGK-250-00 burner with a nominal productivity of 135 m³/h has a length of 1,914 mm);
- high noise level for medium-pressure injection burners when a gas jet flows out and air is injected;
- dependence of the supply of secondary air on the vacuum in the furnace (for low-pressure injection burners), poor conditions for mixture formation in the furnace, leading to the need to increase the total excess air coefficient doos = 1.3...1.5 and even higher to ensure complete combustion of the fuel.
Gas injection burner IGK
1
- frame, 2
- stabilizer, 3
- nozzle, 4
- noise suppressor
size table
| Designation | Dimensions, mm | Weight, kg | |||||
| L | H | c | d | a | b | ||
| IGK1-15 | 650 | 110 | G 1/2 | 4,3 | d 57 | 90 | 3,3 |
| IGK1-25 | 910 | G 3/4 | 6 | d 76 | 119 | 7 | |
| IGK1-35 | 980 | 130 | G 3/4 | 6,6 | d 89 | 134 | 9 |
| IGK4-50 | 1198 | 200 | G 1 | 4,4 | d 85 | 160 | 15,2 |
| IGK4-100 | 1465 | 280 | G 1 1/4 | 6,2 | d 118 | 204 | 29,2 |
| IGK4-150 | 1926 | 330 | G 2 | 7,5 | d 144 | 264 | 35,1 |
Specifications
| The name of indicators | IGK 1-15 | IGK 1-25 | IGK 1-35 | IGK 4-50 | IGK 4-100 |
| Nominal thermal power, kW | 220 | 425 | 500 | 820 | 1570 |
| Nominal gas pressure, kPa | 70 | 70 | 70 | 70 | 70 |
| Excess air coefficient at nominal mode | 1,02 | 1,08 | 1,03 | 1,05 | 1,04 |
| Overall dimensions, mm: | |||||
| - length | 650 | 810 | 980 | 1180 | 1480 |
| - height | 180 | 220 | 290 | 360 | 505 |
| - width (diameter) | 140 | 200 | 200 | 320 | 450 |
| Weight, kg | 6 | 7 | 9 | 16 | 25 |