Using burners for hard soldering and for soldering brass
Soldering allows to make inseparable tight connection of two metal parts by means of peculiar “gluing” of them by some kind of melted material. solder. The latter must show high adhesion to the joined metals, i.e. be very “sticky”, and have sufficient strength after curing.
The melting point of the solder should be higher than the service temperature at which the soldered object is operated, and at the same time lower than the melting point of the base material.
The gas torch is just the right thing to heat up the solder and thus make it viscous enough.
Obviously, for the convenience of work, its torch should maintain a stable shape and temperature.
The advantage of this tool is the ability to work areas with a large area. an electric soldering iron will not be able to perform such a task.
In this case, a simple low-power torch can be made without much trouble with your own hands.
A lot of useful things can be done with the help of a homemade torch. The soldering capability is fully sufficient for brazing copper and brass vessels in radiators, intercoolers and heat exchangers, as well as for brazing with solid solder.
Besides only with the help of such tool it is possible to take apart the radiator in order to replace its core, and also to make replacement of honeycomb in it.
Such torch will also be useful during car body repair, when high temperature is not only unnecessary, but also highly undesirable, because it can cause warping of this part of the car.
To restore a small damaged area, to braze a hole with brass, to perform a “jeweler’s” alignment. for all these works this tool will be quite suitable.
You also need a little heat if you want to dismantle a part that is inter-tensioned, that is pressed in.
It might be a bearing cage or a bush.
Atmospheric torches
This type of burner draws in air according to the jet pump principle: gas is passed through an ejector, where its pressure drops because of its high speed (Bernoulli’s law); air is sucked into the gas flow due to the pressure drop. The strengths of this device include the following:
- Simple design.
- Compactness.
- Energy independence.
- Low noise level.
- Low cost.
- The possibility of easy conversion of solid fuel boilers for gas fuel: an atmospheric burner need only be installed in the ash-pan chamber.
The principle of operation of atmospheric burnerDespite the fact that it is impossible to “load” too much air into the gas stream only due to the jet effect, so burners with high power can not be atmospheric.
Power limit for atmospheric burners is 9 kW on average (the approximate value of the maximum heated area. 90 sq.m.). м).
Average straight burner
As you see, I did not care much about the names of burners, it is necessary that the titles were different. You have to call them something. The following burner differs from the previous ones in the geometry of its components, but the principles of operation are the same.
This torch has softer flame, so it is better to use it for heating (annealing wire, patination) or in places where previous torches couldn’t reach. It has the same flame spreader as the previous burners. And peculiarly made air intake.
There is no drawing on this burner, because the basic parameters are the same as in the previous burner. Header and flare piece and duct diameter are the same. And most importantly, the diameter of the nozzle is the same.
Types and classification
According to the purpose devices are divided into professional and household.
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For works connected with metal processing: for soldering, blacksmithing, welding.
- Products for civil works, road construction, roofing, wood burning, and to remove old paint.
- Process equipment for various purposes. For example: drying chambers, food industry tools.
From household it is a gas stove, home stove nozzles, heating boilers, gas convectors.
Domestic can include devices of the home workshop. It is here that most often there are burners by their own hands, not only manufactured, but originally designed to perform specific tasks.
In the first type, air (or oxygen) is captured by the supplied stream of gas. In the latter, the gas-air mixture is obtained in the pre-chamber.
Options for homemade burners
You and I already know that one of the main elements of the device is a valve. Powerful large-scale models must be equipped with industrial-type valves. You can buy these valves, or you can use the old ones, as long as the integrity of the device is intact and there is no gas leakage.
With such dimensions use a standard 50-liter gas cylinder, equipped with an angle valve and reducer.
Burner with a valve BK-74
Cylinder and gas burner. The main thing to remember: this valve should only be used for flame control. Stop the gas flow only at the cylinder itself. BK-74. oxygen cylinder valve to which knob with hose from cylinder connected is fixed. Screwed to the valve is also a cap with a hole for the nozzle, here you can element from the blowtorch or gas stove. A nozzle of refractory steel is welded to the cap on two wires.
In order to ensure that air enters the combustion zone, the distance between cap and nozzle should be no less than 15 mm. Nozzle position is determined by the wire holders so that the burner flame is exactly centered. How to light the flame: slowly open the valve by bringing a lit match to the nozzle. The flame is adjusted with a valve.
Burner converted from acetylene gas cutter
Homemade gas torch is perfectly made from acetylene torch, which has a faulty faucet for oxygen. In this case, the mixing chamber needs to be redesigned: everything must be removed from it, so that it becomes lighter, this also applies to the valve and the oxygen barrel. The rest of the hole has to be soldered.
Connect reducer hose from gas cylinder to nipple. For the convenience of work on the mixing chamber with the coupling nut set the tip at an angle of 45°. Weld nozzle to flange, which is then screwed on the thread of the nozzle. Make nozzle the same way as in the first variant with BK-74 valve.
The gas mini torch
The drawing of the gas burner. This is called “small” work. for example, jewelry. In this mode, it is more convenient to use special mini-apparatus. Such a gas burner from improvised materials is made very simply. The main element in it is a needle for pumping balls. With this needle you need to work: first make a hole in the form of a kerf approximately in the middle or a little further. Some versions of the gas pins already have this hole, so let’s rejoice and get on with our work.
We take another needle, this time from the syringe, bend it at an angle of 45 °. The end of the needle should be sharpened so that its sharp end turns into a cut at a right angle, and the needle became similar to a narrow metal tube. Insert the syringe needle into the ball needle so that both ends of the needle come out of the larger needle. In this position, the needles should be soldered together. After that, to the base of the needles we connect the droppers with clamps to regulate them.
The clamps must be placed as close as possible to the needles and fastened together. they will have the function of valves, that is, to regulate the supply of gas and atmospheric air. After connecting the gas source your burner will be ready to work. For all its simplicity and compactness, you can get up to 1000 ° C on it. And do not forget the safety precautions, with this baby need to work very carefully.
So, to build a gas burner with their own hands a) realistic; b) beneficial; c) useful. It is enough to decide what kind of work you plan to do, to determine the type and dimensions. The device of the gas burner from a physical point of view is simple, the main thing is to follow our advice regarding the main elements. We wish you fast decisions, quality valves and a steady flame.
Safety when working with gas
Let’s start with the safety precautions. Start working with gas with the smallest 5-liter cylinder. Buy a new one and fill it with propane at the nearest gas station. Ask your gas station attendant to tell you how to properly store, transport, fill and use your gas cylinder. He would gladly do it, because it is just boring for him to refill the cylinders all day long.
Get a good, adjustable regulator right away. It costs 700-1500, but it is nothing when it comes to safety. The pressure gauge should show divisions from 0.1 to 0.6 MPa (mega-pascals). Attention! The pressure regulator tap works not like a water tap, but on the contrary: to increase the pressure, we need to turn it clockwise, i.e.е.
The melting furnace burner, as well as the burner for the gas furnace, usually works in the pressure range of 0.15 to 0.25 MPa. It’s easier for me to count pressure in atmospheres, so it’s 1.5 to 2.5 atmospheres. Do not turn out the pressure regulator for more pressure, we simply do not need it! My gas burner for the melting furnace is now working at 1.5 atmospheres, which is enough to have liquid aluminum floating in the crucible in 15 minutes.
It is strongly recommended that working with gas in the open air. Especially while the gas burner is not yet set up. In an enclosed space 10-15% of propane concentration in the air is enough to cause an explosion. It is almost unreal to explode in the air when working with gas. In order to explode a 5-liter gas cylinder, it must be thrown into a large fire for 3-4 minutes. Only then will it explode.
It is also highly recommended to use a long gas hose of at least 3-5 meters. It is necessary to fix the hose to the pressure reducer with a clamp with a screw tightening. In addition to the pressure reducer, you should also have a valve of some kind, located directly next to the burner.
This is necessary in order to avoid running to the cylinder every time to open/close the gas. A good idea is to have a cylinder behind the corner in a special metal cabinet with a padlock. I used another gas torch from acetylene torch instead of the tap, only instead of the nozzle I connected the hose of my torch.
It’s about. called. The Reynolds number Re, which shows the relationship between flow velocity, density, viscosity of the fluid and the characteristic size of the area in which it flows, e.g. the diameter of the cross section of the pipe. Re is a good indicator of turbulence in the flow and its nature. If, for example, the tube is not round and both of its characteristic sizes are larger than some critical value, there will be vortices of the 2nd and higher orders.
Not all homemade gas burners are accurately calculated according to the laws of gas dynamics. But, if you arbitrarily change the dimensions of details of successful design, Re fuel or sucked air can jump beyond the limits, which it adhered to the author’s product, and the burner will become at best a smoking and voracious, and quite possibly dangerous.
Injector diameter
The determining parameter for the quality of a gas burner is the diameter of its fuel injector section (gas nozzle, nozzle, nipple. synonyms). For propane-butane burners at normal temperature (1000-1300 degrees) it can be roughly taken as follows:
- For heat power up to 100 W. 0,15-0,2 mm.
- For 100-300W power. 0.25-0.35mm.
- For 300-500W power. 0.35-0.45mm.
- 500-1000W power. 0,45-0,6mm.
- For 1-3 kW power. 0,6-0,7 mm.
- For power 3-7 kW. 0,7-0,9 mm.
- For 7-10 kW. 0,9-1,1 mm.
In high-temperature burners, the injectors make more narrow, 0.06-0.15 mm. An excellent material for the injector will be a section of needle for a medical syringe or dropper; you can pick up a nozzle for any of these diameters. Ball inflator needles are worse, they are not heat resistant. They are used more as air ducts in supercharged micro-burners, see. further. In the igniter capsule (primer) it is soldered with hard solder or glued with high-temperature adhesive (cold welding).
Power
Do not make a gas burner with more than 10 kW power in any case. Why? Let’s assume that the efficiency of burner is 95%; for an amateur design this is very good. If the power of the burner is 1 kW, it will take 50 watts to heat the burner by itself. You can get burnt by the 50 watt soldering iron, but there is no danger of an accident. But if you make the burner for 20 kilowatt, then 1 kilowatt will be superfluous, it is already left unattended iron or electric stove.
The fuse
The third factor determining the safety of the burner is the composition of its fittings and the manner of using it. In general, the scheme is as follows:
- The burner under no circumstances should be put out with the adjustment valve, the fuel supply is stopped with the valve on the cylinder;
- For burners with power up to 500-700 W and high-temperature (with narrow injector, excluding passing of Re gas flow over the critical value) fed by propane or isobutane from gas cylinder up to 5 liters at ambient temperature up to 30 degrees, it is acceptable to combine adjustment and cutoff valves in one. standard on the cylinder;
- In burners with more than 3 kW output (with wide injector), or powered from a cylinder of more than 5 liters, the probability of “overshooting” Re over 2000 is very high. Therefore, in such burners between cut-off and control valves, a pressure reducer is necessary, which maintains pressure in gas supply line within certain limits.
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Quality and safe heating: choosing a gas burner for the furnace
Gas burners, also called nozzles are key elements in the construction of any gas furnace.
The task of such a device is to create a mixture of fuel, in this case natural gas, and air in order to maintain the combustion process in the heating device.
No need to run to the store for expensive equipment How to make a gas water boiler with your own hands
Gas boiler unit for obtaining thermal energy for space heating or water heating by combustion of gaseous fuel. It is possible to make such a device yourself.
It is important to correctly calculate the parameters of the equipment and do not ignore the safety rules. The main difficulty lies in obtaining permits for the operation of homemade gas boiler.
Even a minimal deviation from the prescribed norms leads to a complete ban on the use of homemade structures, so only a person with extensive experience in the installation and maintenance of such installations should make the gas boiler himself.
A burner with own hands. drawings
with these dimensions, the burner is designed for cylinders of up to 5 liters.
The inner diameter of the tube insert (1) should be 0.5 mm smaller than the inner diameter of the nozzle. A washer (2) with holes for air is welded inside. The sleeve (2) fixes the tube with the nipple.
The design is different in that by moving the tab in the nozzle it is possible to adjust the air inlet through the holes for ventilation. and as a result the temperature of the fire can be adjusted in a wide range.
