Materials:
- fireclay bricks – 8 pcs.;
- fechral wire Х23У5Т 1 mm 18 m;
- steel wire;
- steel cylindrical tank;
- insulation;
- thermostat REX-C100 or equivalent;
- thermocouple at the required temperature;
- solid state relay;
- ceramic barrels – 2 pcs.;
- case from a computer power supply;
- electrical cord with plug.
Making a melting furnace
The melting furnace muffle is made in the form of a barrel. To do this, 6 fireclay bricks are cut with a grinder with a diamond wheel to obtain rivets.Before cutting, you should draw a template on paper to determine the optimal size of the segments.
Ideally, make a frame for attaching the grinder and make a carriage for sliding the brick. In this case, the rivets will be smooth and identical.
A home-made spiral of fechral wire with a cross-section of 1 mm and a length of 18 m will be used as a heating element of the melting furnace. With these parameters, its heating power will be 1.7 kW. In order for the spiral to fit inside the muffle, the wire must be wound around a rod with a diameter of 10 mm.
To place the spiral in the muffle, you need to make 5 horizontal grooves in the rivets. On one of them, transitions are made between the grooves, which will allow you to lay the wire connecting the spiral. The ends of the heater are brought out through holes in one of the bricks. The rivets are assembled into a barrel and tied on the outside with steel wire placed in pre-made narrow grooves.
The resulting muffle is placed in an available cylindrical steel container. To do this, thermal insulation is laid on its bottom, steel supports are built on top, on which 2 fireclay bricks are installed. The muffle itself is located on top of them. The space between the barrel and the walls of the container is filled with thermal insulation. Before this, the ends of the spiral are brought out.
A thermostat and a solid-state relay must be installed outside the container.
This can be conveniently done by securing the old case from the computer power supply.
Before this, a thermocouple specially selected for the required temperature is connected to the thermostat.It should be noted that the REX-C100 thermostat, often used for melting furnaces, has three modifications that differ in the temperature control range. If the stove will be used to work with ceramics and steel, then you need to take the version with adjustment up to +1300 degrees Celsius. Be sure to remember to insulate the walls of the holes in the metal container for the output of the spiral with ceramic barrels.
In this design, the melting furnace can already be used for melting aluminum. Without a thermally insulating cover, it will take 1.5 hours to warm up to the required +660 degrees Celsius, so it is better to make a cap. The proposed stove design is easily disassembled. This is very important in the absence of a normal thermal insulator, when ordinary mineral wool is used, which must be changed after each use of the smelter. The ability to precisely adjust the heating of the stove makes it possible to work not only with aluminum and ceramics, but also to perform hardening and tempering of steel products.
