DIY hydrogen welder. DIY hydrogen welding

The design of this device has a larger number of working plates, modified side plates and a reliable union for the outlet of a combustible gas mixture), but an electrolyzer operating on the same principle.

For those who first encounter such a device, it is not out of place to explain in the most general terms (and remind the rest) what is the essence of this kind of constructions. And it is quite simple.

Between the side plates, connected by four pins, there are metal plate-electrodes separated by rubber rings. The inner cellular cavity of such a battery is 1/2 ... 3/4 of the volume filled with a weak aqueous solution of alkali (KOH or NaOH). The voltage applied to the plates from a direct current source causes decomposition (electrolysis) of the solution, accompanied by abundant evolution of hydrogen and oxygen. This mixture of gases, having passed through a special liquid seal (Fig.1a), enters the burner further and, burning, allows obtaining a high temperature, which is so necessary for many technological processes (for example, cutting and welding metals) - about 1800 ° C.

Fig. 1. Cutting and welding machine using electrolysis products of a weak alkaline solution:

a - block diagram, b - finished homemade design:
1 - power supply unit with rectified mains voltage, 2 - electrolyzer, 3 - liquid shutter, 4 - gas burner, 5 - ammeter, 6 - device switching knob, 7 - operating mode change knob (abrupt change in power supplied to the load), 8 - knob potentiometer control, 9 - electric cord storage bracket in a folded state, 10 - portable wooden case, 11 - plug.

The performance of the cell depends on the concentration of alkali in the solution and other factors. And most importantly - on the size and number of electrode plates, the distance between them, which, in turn, is determined by the parameters of the power supply unit - power and voltage (based on 2 ... 3 V per galvanic gap between two plates located next to each other ).

The designs of the DC power supply proposed by me are available for manufacture in the conditions of a "home workshop" and for a novice DIYer. They are able to ensure reliable operation of even "eighty-cell" (plate-electrodes for such - 81 pieces) electrolyzer, and even more so - "thirty-cell". A variant, the schematic diagram of which is shown in Fig. 4, allows, moreover, to easily adjust the power for optimal matching with the load: at the first stage - 0 ... 1.7 kW, at the second (when SA1 is turned on) - 1.7 ... 3.4 kW.

And the corresponding plates for the electrolyzer are offered - 150x150 mm. They are made of roofing iron with a thickness
0.5 mm. In addition to the 12-mm gas outlet holes, four more installation (diameter 2.5 mm) holes are drilled in each plate, into which knitting or bicycle needles are threaded during assembly. The latter are needed for better centering of the plates and gaskets, and therefore are removed from the structure at the final stage of assembly.

Fig. 2. Electrolyzer ("eighty-cell" version):

1 - side plate (plywood, s12, 2 pcs.), 2 - transparent cheek (plexiglass, s4, 2 pcs.), 3 - electrode plate (sheet metal, s0.5; 81 pcs.), 4 - separating sealing ring (5-mm rubber acid and alkali-resistant, 82 pcs.), 5 - insulator sleeve (cambric tube 6,2x1, L35, 12 pcs.), 6 - MB hairpin (4 pcs.), 7 - MB nut with locking a washer (8 pcs.), 8 - a tube for the output of a combustible gas mixture, 9 - a slightly alkaline solution (2/3 of the internal volume of the electrolyzer), 10 - a contact output (refined copper, 2 pcs.), 11 - a fitting ("stainless steel"), 12 - union nut М10, 13 - union washer ("stainless steel"), 14 - collar (acid and alkali-resistant rubber), 15 - filler neck ("stainless steel"), 16 - union nut M18, 17 - filler neck washer (" stainless steel "), 18 - sealing washer (acid- and alkali-resistant rubber), 19 - filler cap (" stainless steel "), 20 - sealing gasket (acid- and alkali-resistant rubber).

Actually, I had to puzzle a lot before the "water burner" became convenient and reliable, like Edison's lamp: turned it on - it worked, turned it off - it stopped working. A particularly troublesome affair turned out to be the modernization not of the electrolyzer itself, but of the liquid seal connected to it at the outlet. But it was worth abandoning the now routine use of water as a barrier against the spread of flame inside the gas-generating battery (through the connecting pipe) and turning to the use of ... kerosene, and everything went right on the spot.

Why was kerosene chosen? Firstly, because, unlike water, this liquid does not foam in the presence of alkali. Secondly, as practice has shown, if kerosene drops accidentally enter the burner flame, the latter does not go out - only a small flash is observed. Finally, thirdly: being a convenient "separator", kerosene, being in the gate, turns out to be fire safe.

At the end of work, during a break, etc. the burner is naturally extinguished. A vacuum is formed in the electrolyzer, and kerosene flows from the right tank to the left one (Fig. 3). Then - air bubbling, after which the burner can be stored as long as you like: at any time it is ready for use. When it is turned on, the gas presses on the kerosene, which again flows into the right tank. Then gas bubbling begins ...

Fig. 3. Kerosene lock and its principle of operation

(a - when the electrolyzer is running, b - at the moment the apparatus is turned off):

1 - bottle (2 pcs.), 2 - plug (2 pcs.), 3 inlet nozzle, 4 - outlet nozzle, 5 - kerosene, 6 - adapter (steel pipe).

The connecting pipes in the apparatus are made of PVC. A thin rubber hose leads only to the burner itself. So after turning off the power, it is enough to bend this "rubber" with your hands - and the flame, giving out at last a light cotton, will go out.

And one more subtlety. Although the power supply unit (see Fig. 4) is capable of providing electricity to a 3.4-kilowatt load, it is very rare to use such a large power in amateur practice. And in order not to "drive the electronics" almost idle (in a half-wave rectification mode, when the output is 0 ... 1.7 kW), it is not superfluous to have at your disposal another power source for the electrolyzer - a smaller and simpler one (Fig. 5).

Fig. 4. Schematic diagram of the power supply unit.

In fact, this is a two-half-cycle, adjustable rectifier known to many homemade people. Moreover, with interconnected (mechanically) "slides" of 470-ohm potentiometers. Structurally, such a connection can be carried out either using a simple gear transmission with two textolite gears, or using a more complex device such as a vernier (in a household radio).

Fig. 5. A version of the power supply using thyristors and a homemade transformer in the circuit.

The transformer in the power supply is homemade. A set Ш16x32 made of transformer steel is used as a magnetic wire. The windings contain: primary - 2000 turns of PEL-0.1; secondary - 2x220 turns of PEL-0.3.

Practice shows: the considered home-made apparatus for gas cutting and welding, even with the most intense operation, is able to properly serve for a very long time. True, every 10 years requires a thorough maintenance, mainly due to the electrolyzer. The plates of the latter, working in an aggressive environment, are covered with iron oxide, which begins to act as an insulator. It is necessary to rinse the plates, followed by stripping on an emery wheel. Moreover, replace four of them (at the negative pole), corroded by acidic residues that gather near the "minus".

The use of so-called drain holes (except for the filler and gas outlet) can hardly be considered justified, which was taken into account when developing the device. Equally optional is the introduction into the circuit of the apparatus of cans for collecting the accumulating superaggressive alkali. In addition, the operation of the "no-bidon" design shows that this "harmful liquid" is capable of collecting no more than half a glass at the bottom of the kerosene valve over a 10-year period. The accumulated alkali is removed (for example, during maintenance), and the next portion of pure kerosene is poured into the shutter.

V. Radkov, Tatarstan
MK 03 1997

This is a delightful simplicity of its idea device, available for home assembly with a minimum of tools and skills used (of course, in the advanced version, everything is complicated by gadgets and tricks). The essence is very simple: we take electrodes, put them in the electrolyte, apply current, collect hydrogen-oxygen at the outlet. Probably, anyone reading this text in childhood or later made a mini-electrolysis installation of the class "entertaining physical chemistry": two pencils in a jar of salt or soda, a battery, wires, test tubes, and cheerfully set fire to hydrogen in a test tube.

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So, this is the same thing, only more powerful by two or three orders of magnitude. This crap gives off a powerful, extremely hot tongue of flame dully out of alkaline water. No gas cylinders, no reducers, gas stations and other dregs - just turn on the voltage. And if you inflate a balloon with her and release it with a burning thread ...

What is needed to get a more or less powerful gas flow? That's right, a large area of ​​electrodes, and the volume of gas per second is directly proportional to it. I will not go into the calculations, especially since I myself have not carried out them, I will just report the optimal parameters. The total area of ​​the electrodes for a noteworthy gas flow should be at least 1000 cm ^ 2 (total for the anode and cathode), preferably from 2000 cm ^ 2. The current density should be of the order of 0.08-0.15A / cm ^ 2 (8-15A / dm ^ 2): with a higher current, the electrolyte will overheat and boil - that is, foam, thousands of it; at less - we lose in gas release. The drop on one pair of electrodes for such a current is 2-3 volts, depending on the concentration of the electrolyte (I took 10%, this corresponds to about 2.2-2.3 volts of drop). Under these circumstances, pumping two huge plates with hundreds of amperes of current at two volts does not seem to be a very sensible solution. It is much better to connect several cells in series: then we can increase the operating voltage and the area of ​​the electrodes many times at the same current. And now it remains only to realize that one electrode plate can be, on one side, the cathode of one cell, and on the other, the anode of the other.
In short, we simply collect the Big Mac from plates alternating with ring-shaped spacers. More plates - more voltage at the same current; more area of ​​one of each plate - more current at the same voltage. An increase in the number of plates increases the total voltage drop across them. Everything is clear on the diagram.

Now about the practical nuances of construction. First and foremost: the material of the electrode pads. Since they have to work in an aggressive environment (strong alkali, electrolytic reactions, temperature 50-80 degrees), there is only one choice from the available one, stainless steel. But even here it is not so simple, there are a lot of brands, and not all are suitable. Experimental (and also partly theoretical and partly comparative-analytical - the study of descriptions of industrial installations for electrolysis gas welding) by means of a widespread and suitable steel was determined: 12X18H10T.

Bukovki - additive metals (chromium, nickel, titanium); numbers - designations of their quantity (0.12% carbon, 18% chromium, 10% nickel, a little - up to 1.5% - titanium). It is not important, this is quite fashionable and frequent steel and it is not very difficult to find it in sheets with dimensions of the type 1000 * 2000 mm (I leave the method of cutting the sheet into plates at the discretion of those who want to repeat the device). Its counterpart - AISI 321 - should also theoretically fit. I don’t know, I haven’t tried it. Titanium-free 08X18H10, for example, rusts and oxidizes, although it would seem that it should be suitable.

It is necessary to make holes in each plate from the bottom and from the top at distances slightly less than the diameter of the gasket from each other (but not less than 0.5-1 cm from the edge of the gasket) - for gas exchange and for electrolyte distribution over the cells. A 5 mm drill is enough.

Remember to solder the wires to the outside of the plates before assembling.

Alkali. NaOH or KOH will do, preferably pure, not technical. Start with a concentration of 10% by weight (in distilled water), then experiment. The higher the concentration, the higher the current, but more foam.

Almost all of the rubber gaskets already sold are oil-petrol-alkali-resistant. I used o-rings (O-rings) of about 130mm diameter. They need one less than the plates.

Tightening plates. Something very weakly flexible and rigid is required. Ideally, the classics of the building are thick, two-centimeter plexiglass. In it, you can also make conclusions and threads for gas and additional. fuel tank. I didn't have plexiglass, I just soldered copper pipes into the last stainless plate and used 27mm plywood for the ties.

If all of the above components - steel, gaskets, screeds - are there, you can put them together, check with a slight blowing of pressure - the gaskets should not protrude and there should not be any etching of air at a pressure of at least 0.5-0.6 atm, pour alkali - and go to the external body kit.

First of all, you should make a water seal. Hydrogen-oxygen mixture, HHO, incredibly evil thing. It detonates with ease, and burns very quickly, without requiring any oxidizing agents (that is, oxygen).

If, during operation, the flame for some reason enters the hoses and reaches the electrolyzer, at best, hot alkali mixed with pieces of gaskets will be spread throughout the entire working room. But this is quite easy to avoid by setting up a simple construction, the essence of which is clear from the diagram. The flame has no chance to slip down the bubbles through a layer of water or other liquid, and thus the combustion slip into the device itself will not occur. The structure is slightly less than completely assembled from plumbing from a hardware store.

Next, you should attend to the burner. As a nozzle, the best that could be found - thick all-metal needles (such as "Record" and the like) from Soviet reusable syringes. But since the idea of ​​using the syringe itself as part of the burner is not the best, I just tore off the nozzle of the syringe and soldered it to the nozzle on a full propane-oxygen burner.
And then an important point follows. In view of the malice already mentioned above Hho in terms of combustion as a whole and especially it, combustion, speed, all possible places in the burner should be tamped tightly, ramming, and clogged with tangled small-small copper wire.

I used several meters of MGTF (there lived about 0.07 or less), thoroughly entangled in copper slurry, which clogged almost the entire "barrel" of the burner and most of its nose. This will almost certainly prevent the passage of the flame into the hoses, even if it is turned off incorrectly (and most certainly - in case of an accidental slip - it will already protect the water seal). I really do not recommend neglecting the volume and quantity of this copper motny. And it should start from almost the very nozzle of the burner.
Little things like hoses, connections, manometer connections, I will not describe in detail, they are made from what is at hand. Vinyl and silicone medical tubes have proven themselves well, they are easy to find the right one that fits on standard plumbing copper tubes of diameter.

Nutrition. As a power supply, everything is simple, how many volts and 8-15 amperes are needed. So far, I use LATR and an OSM-0.63 transformer (600 watts) that steps down to 110 volts, after which there is a 50 ampere diode bridge (with a margin), a filtering electrolyte and an ammeter to control the current. The voltage currently consumed is 68 volts, the current is 8-10A, respectively, the power is about 500-600 watts. If the device is expanded to about 140 plates, a direct network transformerless connection will become possible, which will bring the device into a state of incredible coolness and which is planned to be done as soon as I get the rubber gaskets - another 110 pieces.

In short, if everything is done, you can turn it on. It is very lazy to describe possible jambs that may appear, here, nevertheless, the site is not with a set of instructions “do it yourself for dummies”. In short, so. First, there may be foam. Foam means dirty electrolyte, dirty plates or overflow / overheating. If there is dirt, wait 20-30 minutes on a low current until it disappears. If there is overflow / overheating, we reduce the current or let it cool down. If the electrolyte is dirty, we use another alkali and distilled or at least melted water. Further, it can spit alkali together with gas. The electrolyte level is too high, drain or let it run until it drops. The pressure does not hold when the burner is closed - it is poisoning somewhere. You need to check. If the device leaks with an alkali between the plates, you need to find out exactly where, look, replace the gasket or plate. Nothing should leak anywhere, neither gas nor liquid. The gas flow is too weak, the flame rushes into the burner or burns the needle-nozzle - reduce the nozzle diameter or increase the gas release rate. By the way, when the plates are warmed up, they can bend and close with each other - this must be tracked and put something between the corners.

I recommend checking for combustion not indoors (otherwise it will fucking, forgive my French, and everything will be in alkali). I pulled it out into the street, when I was convinced of safety - I brought it back inside. If everything is done correctly, at the end of the needle, either a pale yellow-pinkish or rather bright yellow (the latter means sodium that has entered the vapor) will light up a flame several centimeters long, almost silent, very poorly blown out. By experimenting with the input power, the concentration of the electrolyte, and the diameters of the nozzle-needles, quite interesting results can be achieved. By the way, this flame burns under water. The glass of the light bulb burns into the air, the thicker glass is white-hot and boils. Thin iron boils, thicker iron warms red-hot and white. It melts (but with difficulty) quartz glass. On the video you can see what and how it can do it.

Many people are accustomed to believe that natural gas is the most affordable and economical fuel. But it turned out that this product has a good alternative - hydrogen. It is obtained by splitting water. The initial component for obtaining such fuel is obtained free of charge. A DIY hydrogen burner for a heating boiler will help you save a lot and not think about going to the store. There are special rules and methods for creating a technical installation designed to generate hydrogen.

How is hydrogen produced?

Information on hydrogen production is often given by chemistry teachers to children in high school. The method of extracting it from plain water is called electrolysis in chemistry. It is with the help of such a chemical reaction that it is possible to obtain hydrogen.

The device, simple in design, looks like a separate container filled with liquid. There are two plastic electrodes under the water layer. An electric current is supplied to them. Due to the fact that water has the property of electrical conductivity, a contact is built between the plates with minimal resistance.

The current passing through the created water resistance leads to the formation of a chemical reaction, as a result of which the required hydrogen is produced.

At this stage, everything seems very simple - all that remains is to collect the resulting hydrogen in order to use it as a source of energy. But chemistry cannot exist without small details. It is important to remember that if hydrogen combines with oxygen, then at a certain concentration, an explosive mixture is formed. This state of substances is considered critical, which limits a person in creating the most powerful home-type stations.

How does a hydrogen burner work?

To create hydrogen-powered generators with your own hands, the classic Brown installation scheme is most often used as the basis. An electrolyzer of this type has an average power and includes several groups of cells, each of which, in turn, has a group of plastic electrodes. The power of the created installation will depend on the total surface area of ​​the plastic electrodes.

The cells are installed in a container that is qualitatively protected from external factors. On the body of the device, special nozzles are fixed for connecting a water main, hydrogen outlet, as well as a contact panel that acts as an electric current supply.

A self-made hydrogen burner according to Brown's scheme, in addition to all of the above, includes a separate water seal and a check valve. With the help of such parts, complete protection of the device from the release of hydrogen is achieved. It is this scheme that many craftsmen use when creating a hydrogen installation for heating a home area.

Home heating with hydrogen

Making an oxygen-hydrogen burner with your own hands is not so easy, it requires some effort and patience. To collect the right amount of hydrogen for heating a house, you need to use a powerful electrolysis plant, as well as stock up on a huge amount of electrical energy.

Experts note that it will not be possible to compensate for the consumed electricity by using a ready-made installation at home.

Hydrogen station for home use

How to make a hydrogen burner with your own hands? This question continues to be the most popular among owners of private houses who are trying to make a reliable and high-quality heating source. The most common way to create such a device is the following option:

  • pre-prepare a sealed container;
  • plate or tubular electrodes are created;
  • the design of the device is planned: a method for controlling it and equipping it with current;
  • additional modules are being prepared for connection to the device;
  • special parts are purchased (fasteners, hoses, wiring).

Of course, the master will definitely need tools, including special devices, a frequency counter or an oscilloscope. Once all the tools and materials are ready, the master can move on to creating a hydrogen heating burner for home use.

Device creation scheme

At the first stage of creating a hydrogen burner for heating a house, the master needs to make special cells designed to generate hydrogen. The fuel cell is distinguished by its completeness (slightly less than the length and width of the generator body), so it does not take up too much space. The height of the block with electrodes inside reaches 2/3 the height of the main building, into which the main structural parts are installed.

The cell can be created from plexiglass or textolite (wall thickness varies from 5 to 7 millimeters). For this, the textolite plate is cut into five equal parts. Next, a rectangle is formed from them and the borders are glued with epoxy glue. The bottom of the resulting shape should remain open.

It is customary to create a fuel cell body for a hydrogen heater from such plates. But in this case, experts use a slightly different assembly method using screws.

On the outside of the finished rectangle, small holes are drilled for holding the electrode plates, as well as one small hole for the level sensor. For a comfortable release of hydrogen, an additional hole 10 to 15 millimeters wide is required.

Platinum electrodes are inserted inside, the contact tails of which are passed through the drilled holes on the upper part of the rectangle. Next, a water level sensor is built in at around 80 percent of the cell filling. All free holes in the textolite plate (excluding the one from which hydrogen will come out) are filled with epoxy glue.

Generator cells

Most often, when creating a hydrogen generator, a cylindrical form of module design is used. The electrodes in this design are made according to a slightly different scheme.

The hole from which the hydrogen comes out must be additionally equipped with a special fitting. It is fixed with a fastener or glued. The finished hydrogen generation cell is built into the body of the heater and sealed from the top (in this case, you can also use epoxy resin).

Instrument body

A hydrogen generator housing for home use is fairly straightforward. But using such a design for high-power stations will not work, since it simply will not withstand the load being exerted.

Before installing the finished cell inside, the case should be well prepared. For this you need:

  • create a fluid supply in the lower part of the body;
  • make the top cover equipped with convenient and reliable fasteners;
  • choose a good sealing material;
  • install an electrical terminal block on the cover;
  • equip the cover with a hydrogen collector.

Final stage

At the end of the work, the master will be able to get a high-quality and reliable hydrogen generator for the heating system of a private house. Further, only the final touches will remain:

  • install the finished fuel cell in the main body of the device;
  • connect the electrodes to the terminal block of the device cover;
  • the plug installed on the hydrogen outlet should be connected to the hydrogen manifold;
  • the cover is placed on top of the device body and fixed through the seal.

The hydrogen generator is now fully operational. The owner of a private house can safely connect water and additional modules for comfortable heating of a private house.

Rules for using the device

A hydrogen jewelry burner for home should have additional built-in modules. Of particular importance is the water supply module, which is combined with a water level sensor built into the hydrogen generator itself. The simplest models are a water pump and controller. The pump is controlled by the controller through a sensor signal depending on the amount of liquid in the fuel cell.

Auxiliary elements are very important for any heating design. It is forbidden and even dangerous to use a hydrogen generator without automatic control and protection modules.

Experts advise purchasing a special system that regulates the frequency of the supplied electric current and voltage level. This is important for the normal functioning of the working electrodes inside the fuel cell. Also, the module must contain a voltage stabilizer and overcurrent protection.

The hydrogen collector is a tube in which a special valve, a pressure gauge and a check valve are built. From the collector, hydrogen is supplied to the room through a special check valve.

The pressure gauge and the hydrogen manifold are very important parts in the hydrogen generator, with the help of which the gas is evenly distributed throughout the room and the overall pressure level is controlled.

Any consumer should remember that hydrogen remains an explosive gas with a high combustion temperature. It is for this reason that it is forbidden to simply take and fill the structure of the heating device with hydrogen.

How to determine the quality of the installation?

Creating a high-quality and safe heating system for your home on your own is a difficult task that not everyone can cope with. For example, even when considering the metal of which the pipes of the device and the electrode plates are composed, you can already face a lot of difficulties.

The service life of built-in electrodes directly depends on the type of metal and its basic properties. Of course, you can use the same stainless steel, but the operation of such parts will be short-lived. The temperature of the hydrogen burner should be around 5000 K.

Measurements are also of particular importance. All calculations should be carried out as accurately as possible, taking into account the required power, the quality of the incoming water and other criteria. If the size of the hole between the electrodes does not match the calculations, then the hydrogen generator may not start at all.

Hydrogen flame is used as an alternative to acetylene. It can be used to carry out the process of welding, cutting, sealing. The hydrogen welding machine ensures the efficiency and safety of the process. The use of hydrogen instead of acetylene in the gas welding process provides greater productivity. The quality of the weld is obtained, and the productivity remains at a high level.

The essence of the process

Hydrogen welding is a type of flame welding. Its essence lies in the mixing of gases - hydrogen and oxygen. The work allows you to get a porous thin seam, however, a large slag layer remains in the welding vessel. To avoid this, a minimum amount of organic matter, namely hydrocarbons, is added to the gas mixture. These substances have the ability to "quench" oxygen.

Choosing an effective gas supply source is considered a difficult issue in organizing hydrogen welding. It is known that it is dangerous to use a hydrogen cylinder for this purpose. Liquefied hydrogen at high concentration causes choking and dizziness. Also a problem is the invisibility of the flame in daylight. During the day, the use of such welding is possible only with the use of sensors. Also, the problem is solved with the help of electrolyzers - devices that decompose water into its components - oxygen and hydrogen.

It must be remembered that this gas is suitable for welding from low-carbon steels, iron, but it cannot be used for welding stainless steel sheets and pipes.

The problem arises from the interaction of hydrogen with nickel at high temperatures. After cooling, gas evolves and forms surface damage. Also, such welding is not used when processing copper.

Application options

The hydrogen welding machine is connected to both household and three-phase electrical networks. It is also used for manual and automated work. During operation, the gas mixture is supplied through the hose to the burner. The temperature is regulated in the range of 600-2600 degrees Celsius.

Any welding machine turns on very quickly - it depends on the ambient temperature, as well as the amount of gas consumption. The small dimensions of the device are capable of providing its high power. The combustion product of hydrogen is vapor, which does not have toxic properties. Therefore, both during operation and during storage, a welding machine based on this gas is absolutely safe. However, the safety requirements should be observed - you need to use a protective suit and glasses when operating the device.

There are the following options for using the equipment:

  • welding;
  • watering;
  • powder spraying;
  • oxygen cutting;
  • thermal hardening;
  • surfacing.

The choice of operating modes provides a wide range of capabilities of the device - from welding of small thickness to cutting thick steel sheets. A high-quality welding machine is an assistant for dentists, jewelers, it is also often used in the repair of refrigeration equipment, as well as in service points.

In addition, the equipment is used in the repair of hubs, engine, radiators, for bodywork.

The safety of the device is achieved thanks to the automatic shutdown system when the pressure level and the permissible electrolyte concentration are reached. This protects against possible explosions and fires.

Pros of hydrogen welding

The advantages of this type of welding are as follows:

  • efficiency;
  • safety;
  • environmental friendliness;
  • compactness;
  • low labor intensity;
  • a wide range of processing materials: steel, noble and non-ferrous metals, glass, cast iron, ceramics, glass;
  • only water is required for operation, uninterrupted operation does not need other components;
  • the hydrogen atmosphere protects the surface from oxidation;
  • no need to recharge.

The latest development is a welding machine capable of connecting pipes with a metal surface thickness of up to 5 mm. The devices are used for welding areas with defects, as well as for cutting metals up to 30 mm thick. Such welding is possible with a balloon supply of oxygen. This gives a clean cut. The metal is quenched, but there is no carbon saturation and no by-product of nitric oxide. Such equipment is used in the metro, tunnel rooms and wells.

Thus, the use of hydrogen welding is an excellent solution for a wide range of fields of activity. The main advantage of the method is its absolute safety, subject to all operating conditions.

In the context of stricter environmental requirements for industrial processes, work is underway to find harmless fuels. Welding works with the use of combustible gases - propane, acetylene and others as the main energy sources - were also paid attention to. As a result of research, it became possible to replace them with hydrogen, or rather a mixture of hydrogen and oxygen.

Hydrogen can be obtained by electrolysis of water, more precisely, an alkaline solution of sodium hydroxide (caustic soda, caustic soda, these are all names for the same substance). The hydroxide is added to the water to speed up the reaction.

To obtain hydrogen, it is enough to lower two electrodes into the solution and apply a direct current to them. During the electrolysis process, oxygen will be released on the positive electrode, and hydrogen on the negative one. The volume of hydrogen released will be twice the volume of oxygen released.

In chemical terms, the reaction looks like this:

2H 2 O = 2H 2 + O 2

It remains to technically separate these two gases and prevent them from mixing, since the result is a mixture with enormous potential energy. Leaving a process unchecked is extremely dangerous.

For welding, hydrogen is obtained using special devices - electrolyzers. To power them, you need electricity with a voltage of 230 V. Electrolyzers, depending on the design, can operate on a three-phase current and on a single-phase one.

Advantages and disadvantages

As a result of the combustion of hydrogen, no harmful substances are formed, in contrast to cases when acetylene is used for welding. This happens because when hydrogen burns in an oxygen environment, water is formed, more precisely, water vapor, which does not contain any harmful impurities.

The flame temperature of the hydrogen-oxygen mixture can be adjusted in the range of 600-2600 ° C, which allows welding and cutting even the most refractory materials.

To obtain hydrogen, only water and electricity are used as raw materials, which makes the cost of work low compared to other types of welding.

All of the above properties make it possible to use hydrogen welding in confined spaces, rooms with poor ventilation, in wells, tunnels, basements of houses.

It is worth noting such an advantage of hydrogen welding as the ability to change the torch nozzle. Hydrogen supports flames of almost any configuration and size.

It is possible to use a thin stream of gas that produces a flame no thicker than a sewing needle, even when working with jewelry made of precious metals. For a thin flame, no additional oxygen is required, which is sufficiently dissolved in the air.

Domestic hydrogen generator

Atomic hydrogen method

One of the types of welding that involves hydrogen is atomic hydrogen welding. Its process is based on the phenomenon of dissociation (decay) of molecular hydrogen into atoms.

For decay, a hydrogen molecule must receive a significant amount of thermal energy. The atomic state of hydrogen is so unstable that it lasts only a fraction of a second. And then hydrogen is reduced from atomic to molecular.

When restoring, a large amount of heat is released, which is used in atomic-hydrogen welding to heat up and melt the metal parts being welded.

In practice, the whole process is carried out using electric welding with two non-consumable electrodes. A conventional welding machine can be used to obtain the required arc starting current. But the holder or burner has an unusual design.

Electrodes and burner

Electrodes with a burner, which is supplied with hydrogen, are located at an angle to each other. An arc is struck between these two electrodes. Hydrogen, or a nitrogen-hydrogen mixture, supplied to the arc zone, under the influence of high temperature transforms into the state of atomic hydrogen.

Since dissociation occurs with the absorption of heat (hydrogen has a cooling effect), the voltage for striking the arc must be high enough - about 250-300 V. In the future, the voltage can be reduced to 60-120 V, and the arc can burn perfectly.

The intensity of combustion will depend on the distance between the electrodes and the amount of hydrogen supplied to the weld zone.

Arc burning

The arc is ignited by short-term closure of the electrodes with each other or on a graphite plate while blowing gas over the electrodes. After striking the arc, the distance to the parts to be welded is maintained within 5-10 mm.

If the arc does not touch the metal being welded, it burns evenly and steadily. They call her calm. At short distances to the workpiece, when the arc flame almost touches the workpiece, a strong, harsh sound is generated. Such an arc is called ringing.

Welding technology is similar to conventional gas welding technology.

Welding using the atomic hydrogen method was invented and researched in 1925 by the American scientist Langmuir. In the process of research, instead of an arc, the heat from the combustion of a tungsten filament was used, through which hydrogen was passed.

In a domestic environment

To use hydrogen welding in everyday life, it is not necessary to buy apparatus for producing hydrogen. They usually have great performance and power. Plus, these generators are bulky and expensive.

In domestic conditions, small amounts of welding are often required, so it is advisable to make equipment for hydrogen welding yourself.

Power and working fluid

Power can be supplied from a car charger or from a homemade rectifier, which can be made with a suitable transformer and a few semiconductor diodes.

Sodium hydroxide solution should be used as the working fluid. It will be a better electrolyte than plain water. As the solution level decreases, you just need to add water. The amount of sodium hydroxide will always be constant.

Housing and tubes

As a housing for a hydrogen generator, you can use a regular liter jar with a polyethylene lid. Drill holes in the lid for the diameter of the glass tubes.

The tubes will be used to evacuate the resulting gases. The length of the tubes must be long enough for the lower ends to be immersed in the solution.

Inside the tubes, electrodes must be placed, through which a direct current is supplied. Places of passage of pipes through the lid must be sealed with any silicone sealant.

Hydrogen removal

Hydrogen will be released from the tube containing the negative electrode. It is necessary to provide for the possibility of its removal using a hose. Hydrogen must be removed through a water seal.

It is another half-liter jar of water with two tubes mounted in the lid. One of them, through which hydrogen is supplied from the generator, is immersed in water. The second removes the hydrogen passed through the water from the shutter and feeds it to the burner through hoses or flexible tubes.

A water seal is necessary to prevent the flame from the burner from passing into the generator when the hydrogen pressure drops.

Burner

The burner can be made from a needle from a medical syringe. Its thickness should be 0.6-0.8 mm. Suitable plastic tubes, parts of ballpoint pen bodies, automatic pencils can be adapted for the needle holder. It is necessary to provide an oxygen supply to the burner from the generator.

The rate of formation of hydrogen and oxygen in the generator will depend on the magnitude of the applied voltage. By experimenting with these parameters, it is possible to achieve a burner flame temperature of 2000-2500 ° C.

A do-it-yourself apparatus that performs hydrogen welding can be successfully used for cutting or for joining by welding or soldering various small parts made of ferrous and non-ferrous metal. This may be needed when repairing various household items, car parts, various metal tools.