A Comprehensive List of Laboratory Heating Devices
Heating is an essential requirement in laboratories for performing everyday operations like solvents purification by distillation. Laboratories’ most common heating devices are Bunsen burners, hot plates, bakers, Florence flasks, test tubes, heating mantles, and muffle furnaces.
The standard heating devices used in labs are
A bunsen burner is a gas burner typically consisting of a straight tube with tiny holes at the bottom. It is often connected to a flammable gas source for heating purposes. Air enters through the tiny holes and mixes with the gas, thus producing a hot solid blue flame.
Most laboratories don’t allow open flame heating because of the risks involved; thus, Bunsen burners are now being overtaken by other heating devices. Utmost safety is needed when using this device.
Hot plates are the ideal reasonably priced alternatively available after Bunsen burner. However, you are advised to check hot plates before use. They are used for heating liquids and substances in flasks and beakers. Hot plates have to be used away from explosive, flammable materials.
A baker is a cylindrical vessel with a flat base and a lip for pouring. Bakers are commonly used for mixing, stirring, and heating liquids. They come in various materials, sizes, and shapes, depending on the application. They can be disposable or reusable.
A crucible is a vessel where substances or metals are melted or subjected to extremely high temperatures to melt or alter their contents. Though they were historically made from clay, crucibles can be made from any material which can withstand high temperatures.
The Florence flask (boiling flask) has a long neck and a round bottom. It holds liquids in the lab and can be swirled and heated easily. Florence flask is used for heating substances that require it to be heated evenly. Its bulbed bottom makes the heat more evenly distributed through the liquid. It is used mostly in distillation experiments.
Never heat this flask when capped. It can result in pressure build-up and explosions.
When using lab water baths to thaw samples, always make sure the temperature is 37℃ because temperatures above 37℃ can affect the coagulation factors, causing erroneous test results.
A test tube (sample tube or culture tube) is a finger-like length transparent cylindrical tube. The top of a test tube is open and closed at the bottom. Its sphere-shaped bottom avoids loss of mass when pouring the contents because of the absence of corners,
Test tubes are used for various lab applications such as qualitative assessment and comparison. Test tubes also make it easier to test and compare many samples.
They come in glass, ceramic, plastic, and metal. Never heat a test tube while it is capped.
Meker burners are extremely high-temperature burners that are used where a very hot flame is required. A grid is located at the top of the Meker burner tube, breaking the flame into numerous smaller flames. This provides a larger area of extreme temperature and a total increase in temperature.
Meker burners can be used with bottled liquid, artificial gas, natural gas, or propane. The maximum temperature of the flame can go up to 1775 ºC.
Erlenmeyer flasks have a thin neck and enlarge toward their bottom. This permits easy mixing and whirling of the flask without the risk of spilling the contents. Erlenmeyer flasks are used to mix, heat, and store liquids. Its wider bottom than the top makes it heat faster due to the larger surface area exposed to heat.
Never heat capped Erlenmeyer flask as this might cause a pressure accumulation resulting in an explosion.
These are commonly used to heat round base flasks for distillations or solvent extractions in rotating evaporation processes. Before using heating mantles, check if there is any damage to the insulation material and spilling of water or other solvents on the mantle.
Never exceed the input voltage when operating since it can lead to damage due to overheating.
Muffle furnaces can reach up to (1800^0 C). Therefore, they should be kept away from flammable or explosive materials in different rooms. Normal glassware should never be placed inside. Heat-resistant crucibles must be removed with appropriate tongs and touched when wearing heat-proof mittens.
It is necessary to understand the nature of samples and heating requirements before choosing heating devices. Adopt the recommended safety devices always and take heed of precautions to avoid accidents.