Furnaces existed since time immemorial. Earlier, it was used to manufacture ceramic objects but now this device is used for heating. Furnace is a generic name and it generally refers to the industrial furnaces used in oil refinery plants. These furnaces are used as heat source for various needs for high temperature heating, that arise in any chemical plant. The fuel to this furnace can be a combustible material or electricity. The ones running on electricity are called the electric arc furnace. There are also induction type furnaces. Heating is achieved through the process of induction. In certain chemical based industries, this direct fired heater is used for applications demanding the boiling point temperatures of certain metals. The ones developed lately have various supporting facilities to make the heating process an easier task.
A household furnace is used to provide heating to the interiors of the house. This is different from the ones used in the industries. The most common fuel for the domestic furnace is the natural gas. There are other cheaper options also, but the maintenance for such heating systems is a little difficult. The metallurgical furnaces are a type of industrial furnace. There are different types of furnaces used for metallurgical purposes. To extract a metal from the naturally occurring ore, various types of furnaces are employed. The common ones are blast furnaces, steel making ones, puddling furnaces, reverberation type, Electric arc furnace, electric induction type. Different type of furnace is used to remelt metal for various purposes. There are vacuum type ones, to achieve higher temperatures in the furnace.
Industrial furnaces are the ones that are used in reactors and are different from the ones used in metallurgical process. The direct fired heater consists of different sections for the heating purpose. Though the heaters developed now-a-days have more facilities and devices, the basic structure must have the important components like the radiant section which consists of the coils that receive heat from the radiation of the flame.
The convection section where in the heat transfer takes place through the process of convection. As it is located above the radiant part, the temperature is comparatively lesser.
The burner is just below the radiant section, situated on the floor of the furnace unit. The vertical burner fires the flame upward to heat up the vertical/horizontal coils in the radiant section.
The soot blower is present in the convection section. The soot deposit in this section is more prominent as the air flows slowly. The soot may interfere with the operation of the furnace, so it is blown using the blower.
The stack collects all the waste gases that come to the top most part of the furnace, and releases it the atmosphere at great heights. Insulation is very important requirement for a furnace. The heat produced must not be let to escape, for proper functioning of the furnace. Materials used for this purpose are the firebrick, or ceramic bricks. These can tolerate very high temperatures and are fire resistant.
No comments:
Post a Comment