|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING Cuts and welds water. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / welding equipment The article describes how to make an improved version of a small-sized, but powerful enough apparatus for gas cutting and welding, which works on the principle of obtaining a hydrogen-oxygen combustible mixture by electrolysis of an aqueous solution of alkali. I have had the first "water burner" capable of cutting and welding even refractory metals since 1985. He made it (and now he has launched a small-scale production of analogues for sale) based on the materials of the magazine "Modelist-Constructor". Now I present to the readers my latest development, which, although improved (a larger number of working plates, modified side boards and a reliable fitting for the exit of a combustible gas mixture), is based on an electrolyzer operating on the same principle. For those who first come across such a device, it is useful, I think, to explain in the most general terms (and to remind the rest) what the essence of such structures is. And she is quite simple.
Between the side boards, connected by four studs, there are metal plates-electrodes separated by rubber rings. The internal 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 an abundant release of hydrogen and oxygen. This mixture of gases, having passed through a special liquid lock (Fig. 1a), goes further to the burner and, burning, allows to obtain a high temperature, so necessary for many technological processes (for example, cutting and welding of metals) - about 1800 ° C. 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 DC source designs I propose are available for manufacturing in a "home workshop" and for a novice do-it-yourselfer. They are able to ensure reliable operation of even an "eighty-cell" (plate-electrodes for such a - 81 pieces) electrolyzer, and even more so - a "thirty-cell" one. A variant whose circuit diagram is shown in fig. 4, it also makes it easy to adjust the power for optimal coordination with the load: in the first stage - 0 ... 1,7 kW, in the second (when SA1 is turned on) - 1,7 ... 3,4 kW. And the plates for the electrolyser are offered in the appropriate - 150x150 mm. They are made of roofing iron with a thickness of 0,5 mm. In addition to the 12 mm gas outlet, four more mounting holes (2,5 mm in diameter) are drilled in each plate, into which knitting or bicycle knitting 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. Actually, I had to break my head a lot before the "water burner" became convenient and reliable, like an Edison lamp: turned it on - it worked, turned it off - it stopped working. Especially troublesome was the modernization of not the electrolyzer itself, but the liquid seal connected to it at the outlet. But it was enough to abandon the use of water, which had become cliched, as a barrier against the spread of flame inside the gas-forming battery (through the connecting tube) and turn to the use of ... kerosene, as everything immediately went smoothly. Why choose kerosene? Firstly, because, unlike water, this liquid does not foam in the presence of alkali. Secondly, as practice has shown, if drops of kerosene accidentally fall into 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 shutter, is safe in terms of fire.
At the end of work, during a break, etc. the burner goes out of course. A vacuum is formed in the electrolyser, and kerosene flows from the right tank to the left one (Fig. 3). Then - air barbation, 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 the gas bubbling begins... Connecting tubes in the device - PVC. Only a thin rubber hose leads to the burner itself. So after turning off the power, it is enough to bend this "rubber" with your hands - and the flame, finally giving out a light cotton, will go out.
And one more subtlety. Although the power supply (see Fig. 4) is capable of providing electricity to a 3,4-kilowatt load, it is very rare for amateurs to use such a large power. And in order not to "drive the electronics" almost idle (in the half-wave rectification mode, when the output is 0 ... 1,7 kW), it is useful to have at your disposal another power source of the electrolyzer - smaller and simpler (Fig. 5). In fact, this is a full-wave adjustable rectifier known to many home-made people. Moreover, with the "engines" of 470-ohm potentiometers connected to each other (mechanically). Structurally, such a connection can be carried out either using a simple gear train with two textolite gears, or using a more complex device such as a vernier (in a household radio).
The transformer in the power supply is homemade. A set of Ш16x32 made of transformer steel was used as a magnetic circuit. The windings contain: primary - 2000 turns PEL-0,1; secondary - 2x220 turns PEL-0,3. Practice shows: the considered home-made apparatus for gas cutting and welding, even with the most intense operation, is able to serve properly for a very long time. True, every 10 years a thorough maintenance is required, mainly due to the electrolyser. The plates of the latter, working in an aggressive environment, are covered with iron oxide, which begins to act as an insulator. We have to wash the plates, followed by cleaning on an emery wheel. Moreover, to replace four of them (at the negative pole), corroded by acidic residues that collect near the "minus". Therefore, it is recommended to pour only distilled water into the electrolyzer, and use the least contaminated alkaline solution with salts (the presence of traces of chemical compounds of sulfuric and hydrochloric acids is unacceptable). The use of the so-called drain holes (except for the filler and gas outlet) can also hardly be considered justified, which was taken into account when developing the apparatus. Equally optional is the introduction of cans into the scheme of the apparatus to collect the accumulating super-aggressive alkali. In addition, the operation of the "canless" design shows that no more than half a glass of this "harmful liquid" can accumulate at the bottom of a kerosene shutter 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. Author: V.Radkov, Tatarstan
Solidification of bulk substances
30.04.2024 Implanted brain stimulator
30.04.2024 The perception of time depends on what one is looking at
29.04.2024
▪ Enterprise SSDs and Mobile HDDs with Cryptographic Erase ▪ 300 GB freeze-ray optical disk storage system ▪ The biological clocks of day and night animals differ in their neural structure.
▪ section of the website Experiments in Physics. Selection of articles ▪ article by Julio Cortazar. Famous aphorisms ▪ article Why do reindeer have different eye colors in winter and summer? Detailed answer ▪ article Work in the wells of cable signaling. Standard instruction on labor protection
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page