How to make a muffle furnace
Muffle furnace - a device with which different materials can be heated. Thus individual heating temperature depending on the material and its intended use. Feature is the presence of a furnace muffle. This element of the device protects the material from contact with the fuel gas. In addition, the main operating portion muffle furnace.
You will need:
cardboard, wax, clay, muffle furnace, file, emery paper, Nichrome wire, SEW wire, metal housing, stainless steel plate
Instruction how to make a muffle furnace
Working chamber usually made of fire clay. Sculpt muffle easy using the form. Take the cardboard. Saturate it with paraffin or stearin. Such a measure will help to avoid sticking form.
Inside the mold, apply clay. In this case layer thickness must be not more than 10 mm. Also Fashion a door. Details must be dry, so leave them on the air.
Dried elements of clay put in a muffle furnace, which can be found in a regular school and dosushit. Drying must be at a temperature of 100 ° C for about two hours. Next, you need to make the firing of parts.
Turn off the oven and allow the parts to cool without removing from the oven. Muffle and adjust the door to each other with a file and sandpaper.
Take the 18-meter Nichrome wire 0.75 mm thick wire SEW 0.8-0.9 and wind on top of the muffle. The first and last round should be shorten and tighten. This will prevent loose winding. Remove the wire SEW.
To avoid the circuit, the gaps between the turns promazhte clay. Once the clay is dry, apply a second layer of clay mixing with asbestos crumbs. The thickness of the second layer - 12 mm. Dry muffle.
Fabricate a metal housing, the size of 270X200X180 mm. Put it in the finished muffle. For more convenient use, the body should be equipped with removable front and rear lids, secured with screws.
On the front cover secure door. Fold-up door must horizontally. At the door, set the ceramic muffle. Clearances seal the clay.
The ends of the wire will lead to the back of the case, and insulate them with ceramic beads. Attach the wire to the pin connector, which connect the cord with plug for connection to the network.
The space between the housing and the heating elements hammer asbestos crumbs. Working with a muffle furnace would be easier if the rear wall and on the door to make the hole. Opening the rear is necessary to install the thermocouple, on the door - to exercise control over the work process. Put on the furnace bottom plate made of thin stainless steel of 0.8 mm thick.