For smelting of metals in the conditions of house workshop not only the minimum theoretical knowledge of metallurgical science, but also the corresponding equipment is required. Construction of the melting furnace – business though difficult, but quite real. It is desirable to perform this work under the leadership of the experienced master founder, but, having necessary skills and materials, it is possible to manufacture the furnace and independently.
It is required to you
- - fire-resistant pipe;
- - shamotny brick;
- - grog clay;
- - liquid glass;
- - nikhromovy wire;
- - chromfir and alyumelevy wire;
- - liquid glass;
- - quartz glass;
- - asbestos;
- - millivoltmeter.
Instruction
1. Prepare basis for the high-temperature melting furnace. For this purpose you need fire-resistant pipe which usually is included in the package of standard shamotny laying. Optimum pipe length is 250-350 mm. Since two of its ends drill on couple of the castle openings necessary for fastening of heating coil as which nikhromovy thread will serve.
2. Calculate thread length from nichrom by formula: L = S x R/1.2, where L – length of nikhromovy thread; R – thread resistance; S – wire section; 1.2 - unit resistance of nichrom; x – the sign of multiplication; / - division sign.
3. Strengthen the required piece of nikhromovy wire in the lower lock of pipe. After that prepare cord with a diameter of 2 mm; it will serve for protection of nikhromovy rounds from short circuit among themselves. Densely reel up cord and nikhromovy thread on pipe in the form of spiral.
4. Fix the second end of wire on the top lock of the pipe put vertically. Miss the mark the ready combined spiral with liquid glass, that is normal office glue. After its drying remove cord that on pipe there was only nikhromovy spiral recorded by glue structure. Finally finish product until ready, having covered pipe with several layers of asbestos.
5. Manufacture the temperature sensor. It is possible to use, certainly, and ready, but it can be very expensive. For the self-made thermocouple it is required alyumelevy and chromfir wire. Such sensor will provide temperature threshold within one thousand degrees that it is quite enough for melting of silver and gold.
6. Twist with each other two pieces of alyumelevy and chromfir wire so that the total length of twist was 10 mm. Connect both pieces among themselves soldering. Build in the ready thermocouple in cover of the furnace and attach to the millivoltmeter. Calibrate instrument scale anew, using melting temperature of several pure metals as check points. Such operation can be performed already in the furnace ready for operation.
7. Make of grog clay top cover of the melting furnace and bottom (under). For production of sweat it is desirable to use shamotny brick. If desired it is possible to equip the ready furnace with inspection window, having made it of quartz glass. Miss the mark inside face of the furnace with graphite paste, having involved her on liquid glass. This lubricant is enough to provide 4-5 working swimming trunks.