When you design a laboratory, the laboratory furnace is a critical element. A lab furnace has many applications for research as well as industrial processes.
Constructing or renovating a lab involves many budgetary considerations. Choosing the right type of furnace helps ensure you get the best performance and the best value.
Find out more about how to choose the best laboratory furnace for your applications. You’ll feel more confident you’re making the right choice.
The interior volume of the lab furnace needs to be large enough to accommodate the samples you want to heat. The furnace will ideally have enough room for more than one sample at a time to improve efficiency.
Benchtop laboratory furnaces are the smallest. Cabinet furnaces are larger. Walk-in furnaces are the largest size.
The exact dimensions will vary by manufacturer. A large laboratory furnace may need a separate power source.
Be sure to consider whether you’ll want to expand in the future. You may save money in the long run by buying a furnace large enough to handle your future growth.
In addition to the size of the lab furnace, its shape is an important factor. You can choose a box or tube unit.
A box unit can have a door in the front that opens vertically or sideways. You can also find box furnaces that load from the bottom.
Tube furnaces are either a split tube or a solid tube. A split tube lets you access the internal chamber frequently.
The maximum working temperature you need is another determining feature when choosing a laboratory furnace. Be sure to choose a furnace with a temperature limit higher than the temperature you need to use.
Using the furnace at its maximum temperature for long periods of time will reduce the lifespan of the heating elements. However, using a high-temperature furnace for low-temperature applications will cause problems with process control. An accurate evaluation of your needs is important.
The type of heater determines the temperature range of the furnace:
- Wire heating element
- Silicon carbide (SiC) heating element
- Molybdenum disilicide (MoSi2)
The temperature of a furnace with a wire heating element can reach 1300ºC. Furnaces with silicon carbide heating elements have a maximum temperature of 1550ºC.
A molybdenum disilicide heating element can reach 1700ºC. Some MoSi2 heating elements will give you a furnace temperature as high as 1800ºC, which you can see at https://www.samaterials.com/461-molybdenum-disilicide-heating-elements.html.
A laboratory furnace uses convective heat transfer. Furnaces have either gravity convection or mechanical convection.
Gravity convection works by the temperature and density differences in the air. Heated air displaces the cool air and directs it toward the heating element. In this way, the interior chamber will reach the temperature you want.
Lab furnaces with gravity convection take longer to preheat. The interior temperature can be unstable and uneven. They’re often more economical to buy and operate, though.
Mechanical convection or forced air convection uses powered blowers. The blowers force heated air through baffles in the interior chamber.
Mechanical convection heats the furnace faster and more evenly.
When you’re building a lab, choosing the laboratory furnace is an important step. You need to consider factors like the size and shape of the furnace. The maximum temperature of the furnace and the type of heating technology are other considerations.
Taking these factors into account, as well as your available lab space and budget, will help ensure you pick the right furnace.
Check out our other How-to articles for more practical tips like this.