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The Role of Muffle Furnace and Precautions for Use

Aug. 19, 2020

Electric muffle furnace, also known as box-type resistance furnace. The high-temperature muffle furnace is universal heating equipment. It can be divided into box furnaces, tube furnaces, and crucible furnaces. There are domestic muffle furnaces and imported muffle furnaces (American muffle furnaces, German muffle furnaces, etc.). The muffle furnace is a cyclic operation type for laboratory, industrial and mining enterprises, scientific research units for element analysis and determination and general small steel quenching, Annealing, tempering and other heat treatment, the high-temperature furnace can also be used for high-temperature heating such as metal and ceramic sintering, dissolution, analysis.

The specific function of the muffle furnace:

(1) The muffle furnace can be used for thermal processing, cement, and building materials industries for thermal processing or treatment of small workpieces;

(2) National standard energy-saving electric furnace for periodic operation, mainly used for heat treatment such as normalizing, quenching and annealing of alloy steel products, various metal parts, or for high-temperature sintering of cutting blades such as diamond

(3) For quenching, normalizing, annealing, quenching and tempering heating of carbon steel, alloy steel, high manganese steel, high chromium steel, and other workpieces.

(4) Heat treatment of various small parts, springs, and molds. High-temperature electric furnaces usually have a temperature of up to 1800 degrees, and a specially treated furnace can reach 1800 degrees.

The Role of Muffle Furnace and Precautions for Use

Electric Muffle Furnace

(5) Pharmaceutical industry: used for drug inspection, pretreatment of medical samples, etc.;

(6) Analytical chemistry industry: as sample processing in water quality analysis, environmental analysis, and other fields. It can also be used for petroleum and its analysis;

(7) Coal quality analysis: used to determine moisture, ash, volatile content, ash melting point analysis, ash composition analysis, element analysis. It can also be used as a general ashing furnace;

The use and precautions of laboratory Muffle Furnace

1. The refractory material of the new furnace contains moisture. In addition, in order to generate an oxide layer on the heating element, it must be baked at low temperature for several hours and gradually heated to 900°C before use, and kept for more than 5 hours to prevent the furnace chamber After being damp, it ruptured due to a rapid temperature change.

2. When the muffle furnace is heated, the furnace jacket will also become hot. Keep the furnace away from combustible materials and keep the furnace easy to dissipate heat.

3. The working life of the heating element depends on the oxide layer on its surface. Destroying the oxide layer will shorten the life of the heating element, and each shutdown will damage the oxide layer. Therefore, it should be avoided after the machine is turned on.

4. The furnace temperature should not exceed the maximum temperature during use, so as not to burn the heating elements, and it is prohibited to pour various liquids and molten metals into the furnace.

5. When doing the ashing test, you must first fully carbonize the sample on the electric furnace, and then put it in the ashing furnace to prevent carbon accumulation from damaging the heating element.

6. After several cycles of heating, the insulation material of the furnace may appear cracks. These cracks are caused by thermal expansion and have no effect on the quality of the furnace.

7. The muffle furnace is an experimental item and should not be used for other purposes. The sample must be stored in a clean crucible and the furnace must not be contaminated.

8. When using the resistance furnace, always look after it to prevent accidents caused by the failure of automatic control. Do not use the resistance furnace when there is no one on duty at night.

9. After using the Vertical Muffle Furnace, the power should be cut off to allow it to cool down naturally. The furnace door should not be opened immediately to prevent the furnace chamber from being suddenly broken by the cold. If it is used urgently, a small slit can be opened first to speed up its temperature drop. When the temperature drops below 200℃, the furnace door can be opened.

10. When using the muffle furnace, pay attention to safety and beware of burns.


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