The mesh asbestos or asbestos grid is a mesh of thin metal used in scientific laboratories to spread the heat evenly. They are almost always used accompanied by a Bunsen burner and a tripod. These grids are used in high school, college, and professional labs.
Asbestos mesh can be used so that a container (such as a glass flask or glass) does not break during heating. When the Bunsen burner flame is below with a tripod, the asbestos grid helps spread the flame and heat evenly over the entire container.
Asbestos mats are often used in combination with an iron ring and a circular holder with a Bunsen burner just below. A clay triangle serves a similar purpose, except that a clay triangle is used with a crucible.
Characteristics of an asbestos mesh
An asbestos mesh is a heat-resistant wire mesh that beakers and other glass materials used in the laboratory can rest on during heating.
It is usually a flat, square piece of mesh. It may have, but does not necessarily have, a circular ceramic center.
The meshes can be made in various sizes, including squares measuring four by four inches (10 × 10 cm), five inches by five inches (12.7 × 12.7 cm), and six inches by six inches (15 × 15 cm).
In this way they can be used in conjunction with the different Bunsen burners and other equipment.
Usually, glass containers have to have flat bottoms in order to stay on the metal rack.
The racks are used to prevent beakers, flasks and other metal jars from breaking due to the impact of heat.
When a glass flask is used on a hot burner, the parts that actually touch the burner get much hotter than the parts that have air between the burner and the glass. This creates stress that eventually creates breakage of the glass.
Bunsen burner
When using a Bunsen burner, an asbestos mesh is usually placed between the metal jar and a ring that is used to keep the jar above the fire.
This serves the purpose of insulating the glass jars from heat to prevent breakage. Also, it can decrease the chances of the glass tumbler falling off the ring.
Asbestos meshes serve the function of spreading the temperature evenly through the glass containers or test tubes when they are heated with lighters.
Elaboration
Most of the grids used in laboratories are made of nichrome wire; they are usually covered with a thin layer of asbestos or asbestos.
This material is flexible enough that it can be separated into long fibers so that it can survive high temperatures. Nichrome is a galvanized iron wire.
Although asbestos has been proven to be a harmful material for health, it is commonly used in laboratories. In the case of scientific laboratories, asbestos is used primarily to insulate equipment or to protect the elements from very high temperatures.
The ores of the fibers contained in asbestos are quite elongated, as well as strong and resistant.
Thanks to these capabilities, these fibers can be separated and are widely flexible; this allows them to be entwined and in this way they can withstand quite high temperatures.
It is a material with a high life expectancy and can withstand a long time of use. It can be placed between a crucible or any other porcelain or glass vessel and a Bunsen burner.
The corners of the grill face inward to prevent deterioration, to improve handling, and to reduce the safety risk of protruding grill edges.
Applications
To use an asbestos screen in a scientific laboratory, three objects must be on hand: a lighter (usually from Busen), a laboratory tripod, and the asbestos grid. In this way glass objects can be heated safely and efficiently.
Glass containers should never be heated directly over a flame, so the screens are a good protector since they distribute the heat.
To take additional safety precautions, be sure to fold the edges of the mesh underneath for greater heat spread.
The asbestos mesh must first be placed on the laboratory tripod. On this rack, place the bottle, glass flask or glass container.
For the mesh to work best, a person should use a glass container in the background. A good example of a flat-bottomed container might be a beaker, or an Erlenmeyer flask.
The Florence flask also has a partially flat bottom and can therefore also be used.
Types
There are two types of asbestos screens. If you want to perform an advanced science experiment on a ring stand, you can use a grid with a ceramic center.
Both types of grates are made of metal and have the same ability to transmit heat efficiently; only that the grate with the ceramic center will allow the heat to be dispersed in an even more balanced way.
The ceramic core in the center of the grill is trapped under very high pressure to prevent peeling or deterioration.
References
- What is wire gauze used for in a laboratory? (2017) Recovered from quora.com.
- Asbestos in laboratories. Recovered from levylaw.com.
- Grid or metal mesh. Recovered from laboratory-chemical.blogspot.com.
- What is the purpose of a wire gauze? Recovered from reference.com.
- Asbestos grid. Recovered from ecured.cu.
- Wire gauze. Recovered from wikipedia.org.