What is the temperature of the acetylene flame, the oxygen acetylene flame oxidation flame oxygen ac

The flame formed by the mixed combustion of acetylene and oxygen is called an oxygen-acetylene flame. The oxygen-acetylene flame has a very high temperature (about 3200 °C), the heating is concentrated, therefore, it is gas welding.

The main use of flames. The combustion process of acetylene (C2H2) in oxygen (O2) can be divided into two stages, firstly, acetylene is decomposed into carbon (C) and hydrogen (H2) under the action of heating, and then carbon reacts with oxygen in the mixture to form carbon monoxide.

co), forming the first stage of combustion; The subsequent combustion in the second stage relies on oxygen in the air, when carbon monoxide and hydrogen react with oxygen to form carbon dioxide, respectively.

CO2) and water (H2O). The above reaction releases heat, i.e., the process of burning acetylene in oxygen is an exothermic process. According to the different proportions of oxygen and acetylene, the oxygen-acetylene flame can be divided into three types: neutral flame, carbonization flame and oxidation flame, the core of the neutral flame is composed of oxygen and acetylene, the temperature is low (800 1200), and the internal flame is mainly composed of the incomplete combustion products of acetylene, that is, the carbon and hydrogen from the flame core and the carbon monoxide and hydrogen gas, the products of oxygen combustion.

The inner flame is located in the 2 4mm part in front of the flame core, the combustion is the most intense, and the temperature is the highest, up to 3100 3150. When gas welding, this temperature zone is generally used for welding, so it is called the welding zone. The outer flame is located on the outside of the inner flame, and the color of the outer flame changes from lilac to orange-yellow from the inside out.

In the outer flame, the carbon monoxide and hydrogen produced by the combustion of the inner flame are fully combusted with the oxygen in the air, that is, the second stage of combustion is carried out. The products of the outer flame combustion are carbon dioxide and water. The outer flame temperature is 1200 2500.

Since carbon dioxide (CO2) and water (H2O) decompose easily at high temperatures, the outer flame is oxidizing.

The carbonization flame is a gas flame formed by the combustion of a mixture when the ratio of the volume of oxygen to acetylene (O2 C2H2) is less, because acetylene has a surplus, so the combustion is incomplete. The maximum temperature is 2700 3000 . The oxidation flame is a gas flame formed by the combustion of the mixture when the ratio of the volume of oxygen to acetylene (O2 C2H2) is greater, and there is excess oxygen in the oxidation flame, and the maximum temperature of the oxidation flame can reach about 3100 3400.

The neutral flame, carbonization flame and oxidation flame described above are suitable for welding different materials due to their different properties. The gas flame formed by the combustion of mixed gas with different volume ratios of oxygen and acetylene (02 C2H2) has a great influence on the welding quality.

Pure acetylene. Burning in the air, the flame temperature reaches 2100 degrees. Burns in oxygen, flame height up to 3600 degrees.

Acetylene is the simplest alkyne, also known as calcium carbide gas.

The structural formula H-C C-H, the simple structural formula CH, the simplest formula (also known as the experimental formula) CH, the molecular formula C2H2, the acetylene center C atom adopts SP hybridization. Electronic h:c c:

h acetylene molecular weight, gas specific gravity, flame temperature 3150, calorific value.

12800 kcal m3, combustion rate in oxygen . The chemical properties are very active, and can cause addition, oxidation, polymerization and metal substitution reactions.

Summary. Hello dear, oxyacetylene flame is a kind of combustion flame commonly used in metal cutting, welding, heating and other processes. The flame is produced by ignition after mixing oxygen and acetylene, where the pressure of oxygen and acetylene is an important factor affecting the combustion effect of the flame.

In general, oxygen and acetylene pressures need to be used in conjunction to achieve optimal combustion. Usually, the pressure of oxygen is MPa and the pressure of acetylene is MPa. At the same time, the pressure of oxygen and acetylene will also be different for different process needs, which needs to be adjusted according to the actual situation.

It should be noted that too high or too low the pressure of oxygen and acetylene will affect the combustion effect and may even cause safety accidents, so it is necessary to operate strictly according to the specified pressure range when using oxyacetylene flames. At the same time, it is also necessary to inspect and maintain the ** system of oxygen and acetylene to ensure its proper operation and safe use.

Hello dear, oxyacetylene flame is a kind of combustion flame commonly used in metal cutting, welding, heating and other processes. The flame is generated by the ignition of oxygen and acetylene mixture, and the pressure of oxygen and acetylene is an important factor affecting the combustion effect of the flame. In general, oxygen and acetylene pressures need to be used in conjunction to achieve optimal combustion.

Usually, the pressure of oxygen is MPa and the pressure of acetylene is MPa. At the same time, the pressure of oxygen and acetylene will also be different for different process needs, which needs to be adjusted according to the actual situation. It should be noted that too high or too low pressure of oxygen and acetylene will affect the combustion effect and may even cause safety accidents, so it is necessary to operate strictly according to the specified pressure range when using oxyacetylene flames.

At the same time, it is also necessary to inspect and maintain the ** system of oxygen and acetylene in Daxiaozhou to ensure its normal operation and safe use.

With oxyacetylene flame spraying, whether the pressure of the oxidizing flame is a little higher than that of the neutral flame.

Hello dear, when spraying with oxyacetylene flame, the pressure of the oxidizing flame and the neutral flame is different. In general, the pressure of the oxidizing flame is a little higher than that of the neutral flame. This is because the oxidation flame needs to oxidize the material on the surface of the workpiece into oxide under the action of oxygen before spraying the coating, so a higher oxygen pressure is required to provide enough oxygen to achieve the oxidation reaction of the material during the combustion process.

The neutral flame, on the other hand, does not require an oxidation reaction, so its pressure can be relatively low. It should be noted that the high pressure of the oxidation flame will also affect the combustion effect, and may even cause safety accidents, so it is necessary to strictly follow the specified pressure range when using oxyacetylene flame spraying. At the same time, the hidden start also needs to ensure that the oxygen and acetylene system balance is in good condition to ensure its normal operation and safe use.

The thermochemical equations for ethylene and acetylene combustion are:

2c2h2(g)+5o2(g)=4co2(g)+2h2o(l)；△h=-2600 kj•mol-1

c2h4(g)+3o2(g)=2co2(g)+2h2o(l)；△h=-1411 kj•mol-1

The heat of combustion is ethylene acetylene, but the flame is high when the flame is heated and the acetylene is burned. Acetylene burns in air or oxygen, and its flame temperature can be as high as 3200 °C. Although the heat of combustion of acetylene is slightly lower than that of ethane and ethylene, it has the least oxygen consumption during complete combustion, the water content in the product is relatively low, and the heat loss required for water evaporation is less, so acetylene can obtain a higher temperature when burning.

A flame formed by the mixed combustion of acetylene and oxygen. By adjusting the oxygen valve and acetylene valve, the mixing ratio of oxygen and acetylene can be changed to obtain three different flames: neutral, oxidizing and carbonizing.

1.Neutral flame oxygen and acetylene are fully combusted, there is no excess of oxygen and acetylene, and the internal flame has a certain reduction. Maximum temperature 3050 3150 . It is mainly used for welding low carbon steel, low alloy steel, high chromium steel, stainless steel, copper, tin bronze, aluminum and its alloys, etc.

2.Oxidation flame Excess oxygen flame is oxidizing, and the weld is prone to porosity and brittleness when welding steel parts. Maximum temperature 3100 3300 . It is mainly used for welding brass, manganese brass, galvanized iron sheet, etc.

3.Carbonization flame acetylene is excessive, there is free carbon and too much hydrogen in the flame, and the hydrogen content of the weld will be increased during welding, and there is carburizing phenomenon in welding low carbon steel. Maximum temperature 2700 3000 .

It is mainly used for welding or welding repair of high-carbon steel, high-speed steel, cemented carbide, aluminum, bronze and cast iron.

10 meters.

GB 30871-2014 stipulates that when using gas welding and gas cutting for hot work, acetylene cylinders should be placed upright, and the distance between oxygen cylinders and them should not be less than 5m, and the distance between them and the operation site should not be less than 10m.

The revised GB 30871 stipulates that "the acetylene bottle shall be installed with an anti-flashback device", and adds that when using an electric welding machine, the distance between the electric welding machine and the hot point should not exceed 10m, and the electric welding machine should be managed as the hot point when the requirements cannot be met, and the acetylene bottle should be installed with an anti-flashback device.

Precautions for electric welding operations

1. Construction workers must obtain special types of work operation certificates and related qualifications.

2. Welding operations in high-risk places and important places must be approved by safety management personnel! No construction shall be carried out in the fire ban zone without going through the fire approval procedures.

3. Before carrying out construction operations, it is necessary to understand the surrounding situation, understand the key parts of fire hazards, and clean up the flammable and combustible materials near the welding construction site to fully understand the internal situation of the welded objects.

4. Containers that have been filled with flammable and explosive materials shall not be welded until they are thoroughly cleaned!

5. The parts of the buried decoration of the Hongqiao with fuelable materials shall not be welded, and the sealed and pressurized vessel pipelines shall not be welded, and shall not be welded at the nearby open flame sites.

Let's compare the chemical formulas of the three first, ethane C2H6, ethylene C2H4, acetylene C2H2

From the chemical formula, we can see that the carbon-hydrogen ratio of acetylene is larger than the most round, so the amount of the same substance is burned by the three, and the two cavities of oxygen collapse are released to burn as much carbon, but acetylene emits the least H2O, and in junior high school physics, the specific heat capacity of H2O is the largest, and water is heated and gasified to absorb heat, and acetylene produces the least water, so the heat absorbed by gasification is the least, and then the heat released by acetylene combustion is the most, and the temperature is the highest, commonly known as oxyalne flame.