SD023Cutting gun

Definition and use of cutting gun

The cutting gun is a tool used to cut metal materials, mainly used to cut ferrous metals such as carbon steel, alloy steel, etc., and can also be used to cut some non-ferrous metals. It is widely used in industrial production, such as machinery manufacturing, shipbuilding, construction steel structure processing and other industries, for cutting large pieces of metal sheets or profiles into the desired shape and size.

The structure of the cutting gun

Gun body and handle:

The gun body is the main part of the cutting gun, and there is a gas channel inside to transport oxygen and combustible gases (such as acetylene, propane, etc.). These channels are designed to ensure that the gas flows in a stable and orderly manner to prevent leakage.

The handle is usually designed to be stable for the operator to hold, and has a valve on the handle to control the flow of oxygen and combustible gases. Some of the handles also have slip lines for added grip stability.

Gas Nozzles:

Gas nozzles and oxygen nozzles are included. Gas nozzles are used to spray combustible gases, and oxygen nozzles are used to spray combustible gases. The position and design of these two nozzles affect the mixing effect of the gas and the shape of the flame.

The splitting gun also features a special cutting oxygen nozzle for spraying a high-speed stream of pure oxygen during the cutting process, which oxidizes and blows away the metal heated to the ignition point.

Mixing chamber:

The mixing chamber is located near the gas nozzle and is where the combustible gas and oxygen are mixed. Here, the two gases are thoroughly mixed to form a gas mixture with high temperature and good capacity to provide the heat required for cutting. The size, shape, and internal structure of the mixing chamber affect the uniformity of the gas mixture and the stability of the flame.

How the cutting gun works

First, combustible gas (such as acetylene) is sprayed from the gas nozzle and oxygen is sprayed from the oxygen nozzle, and in the mixing chamber of the cutting gun, the gas and oxygen are mixed in a defined ratio. The gas mixture is then ignited by an ignition device to produce a high-temperature flame that can reach temperatures of around 3000°C. When the flame is aimed at the metallic material, the metallic material is heated to its ignition point (for steel materials, the ignition point is about 1300 - 1350°C). At this point, a high-speed stream of pure oxygen is ejected through another oxygen channel (cutting oxygen), and the oxygen undergoes a violent oxidation reaction with the metal that has been heated to the ignition point, oxidizing the metal into oxides (e.g., in the case of iron, oxidation to iron oxides). These oxides are blown away by the impact of high-velocity oxygen streams, which cut the metal apart.

The main types of cutting guns

Acetylene cutting gun:

Using acetylene as a combustible gas, the high temperature and heat concentration of the flame produced by the mixed combustion of acetylene and oxygen enable the cutting of thick metal materials, such as steel plates up to 300 mm thick.

However, acetylene is a flammable and explosive gas, and special attention needs to be paid to safety during storage and use, such as special acetylene generators or acetylene bottles, and the pressure and flow of the gas should be strictly controlled.

Propane Cutting Gun:

Propane is used as a flammable gas. Propane is safer, more stable, and less expensive than acetylene.

However, propane combustion produces a slightly lower flame temperature than acetylene, so the cutting speed may be slightly slower, and it is generally suitable for cutting metal materials up to 200 mm thick.

Precautions for the use of the cutting gun

In terms of safety protection:

Operators need to wear protective equipment such as protective eyewear, protective gloves, and fireproof (mainly actual report) overalls to prevent flames, splashing slag, and hot metal from getting sick to the eyes and skin.

Set up fire barriers around the workplace (mainly based on actual reports) to prevent fires caused by sparks and slag. And make sure that the work area is well ventilated to avoid the accumulation of combustible gas.

In terms of equipment inspection:

Before use, check whether the various parts of the cutting gun are in good condition, such as whether the nozzle is blocked, whether the valve is flexible, whether the pipeline is leaking, etc. At the same time, the safety of the gas supply device is checked.

Perform regular maintenance and maintenance on the cutting gun, such as cleaning the nozzle, replacing the seals, etc., to confirm the performance and service life of the cutting gun.

In terms of operational specifications:

When ignition, the acetylene (or other gas) valve on the cutting gun should be opened first, and a little gas should be released before ignition. In this way, it can avoid the phenomenon of deflagration caused by the accumulation of gas inside the cutting gun after ignition and then the gas is turned on.

Properly adjusting the flame is the key to a safe and effective cut. Flames are divided into carbonization flames, neutral flames and oxidation flames, and neutral flames are generally used when cutting metals.

During the cutting process, keep the appropriate angle (generally vertical) and distance between the cutting gun and the material to be cut, and control the cutting speed. If the cutting speed is too fast, it may lead to impermeable cutting; If the speed is too slow, the cut will be too wide and there will be too much dross.