What Is A Melting Furnace
A melting furnace as the name implies is used for heating solid materials until they turn into a liquid form. The most common of these materials are gold, aluminum, brass ,bronze as well as steel. Some Melting Furnaces are also specifically designed for the melting of scrap metals. The basic design of a melting furnace is a vessel or container in which the material to be melted is placed. This is then heated to a point in which the material is melted and turns into liquid form, then it is poured off into a mold or container until it solidifies. At that point it can be used for what ever purpose it was intended for. There are many different grades of metal that can be produced from a melting furnace. This is done two ways by adding ingredients to the molten metal which cause all the impurities to float to the surface thereby leaving the more pure metal at the bottom, this is known as slag, it is an important part in process of melting all types of metals and gold. The pure metal is then siphoned off. The other process that is used is to remove more of the impurities by doing the process a number of times in the melting furnace.
The Different Types Of Melting Furnace
There are quite a number of different types of the Melting Furnace. These include the Electric Arc Furnace, the Induction Furnace, the Crucible Furnace, the Cupola Furnace and finally the Blast Furnace. Here is a basic outline of how each of these work.
The Electric Arc Furnace uses vertical carbon rods for electrodes. These carbon rods are lowered onto the metal where an arc is produced which heats the metal. As this process happen the rods are lowered further down until they reach the bottom of the melting furnace at which time the voltage is turned up to speed up the melting process. Other ways to speed up the process is to inject oxygen into the molten metal by high pressure jets. Typically there are three carbon rods in the machine. Normally a transformer is located next to the melting furnace. What this does is to regulate the electrical current to make sure that the heating process is consistent.
The Induction Furnace is also a melting furnace that uses electricity, although in this case there is also a magnetic field involved as well. The principle of this is where an electrical current passes through a conductor whilst also passing through the magnetic field. These currents when passing through the coil are what heat the metal or precious metals. Once the charge has been melted the magnetic current also passes through the coil. This causes an interaction where the electromagnetic fields of both the coil and the current will cause a stirring effect which allows for a better evenness of temperature and mixture of the metal being melted.
The Crucible Furnace is a type of melting furnace that that goes back centuries. It is the simplest form of a melting furnace. The crucible is basically a container or vessel that can stand very high temperatures. The crucible is mounted on a stand which allow the contents to be emptied out after being heated. These days there are two methods by which the crucible furnace is heated. The two methods are gas or oil powered and electrical power. In the gas method the crucible is heated by the direction of the heat directly onto it, whereas the electrical method heating elements are used as the source to melt the metal.
The Cupola Furnace is a melting furnace that is cylindrical in shape and looks a lot like a forty four gallon drum. The way to measure the size of these is by diameter and can be anywhere from half a meter up to ten meters. It basically rests on a four legged stand. The outside of the cupola is made from steel while the inside has a lining of clay or special bricks to protect the interior. The method by which the metal is melted is to have numerous layers inside of the cupola of metal and coke. Limestone is also added to help extract the impurities. The coke is then lit and once burning oxygen is introduced from the side to allow the heating process. When the metal melts it drops down into a container at the bottom of the unit. By layering the coke then metal the process can produce a continuous flow of supply of whatever metal is being used.
The Blast Furnace is a melting furnace that works by the force of heated air from the bottom of the furnace with the iron ore, coke and limestone placed in the top. It also has a special lining inside that is heat resistant. These units are very large and once started can operate for over five years without shutting down. The time it takes for the metal to come out the bottom is roughly eight hours, so the melting furnace can be continually refilled. The quality of this metal is of low grade due to the amount of carbon in it. This carbon makes the metal very brittle so in order to be useful it must go through further processes. These processes depending on the strength required will produce wrought iron then cast iron and finally the higher quality of steel.
The Melting Furnace Has Changed Our Lives
The melting furnace changed the way we have lived over the years especially during the industrial revolution. Over time the melting furnace has been improved and made more efficient and environmentaly friendly. Even today you are able to purchase a small melting furnace if you would like to try your hand at melting different products. You might have your own workshop where you can control the quality of metals that you need to use or you could have a lot of scrap iron and melting it down makes it more usable and easier to handle. Maybe you like exploring for gold and using the melting furnace will allow you to make your own ingots. Either way the melting furnace has had a big impact on all our lives.