Acetylene generator is a device used to produce acetylene gas on-site through chemical reactions. Its core function is to react solid calcium carbide (calcium carbide) with water to generate acetylene gas, which is then provided to applications that require the use of acetylene.
1. Function: Produce acetylene gas on site according to demand
Acetylene has very active chemical properties, is unstable under high pressure, and is prone to explosion. Therefore, traditionally transporting and storing it in large quantities compressed in steel cylinders carries high risks. The acetylene generator solves this problem by avoiding the risks of storing and transporting high-pressure acetylene: it is only produced on-site when needed, and the gas pressure is usually lower, resulting in relatively higher safety.
Produce according to demand and reduce waste: The reaction rate between calcium carbide and water can be controlled according to the amount of gas used, allowing for immediate production and use.
2. Working principle (chemical reaction)
The core of an acetylene generator is the following chemical reaction:
Calcium carbide+water → acetylene+calcium hydroxide (hydrated lime) and release a large amount of heat.
CaC2+2H2O→C2H2↑+Ca(OH)2+热
The generator regulates the reaction rate and gas production by controlling the contact mode between calcium carbide and water (such as drip, immersion, drainage, etc.).
3. Application
Acetylene generators have been widely used in certain specific situations in the past and present
Metal welding and cutting: This is the main use. Acetylene can produce a high-temperature flame (oxyacetylene flame) of up to 3000 ° C when burned in oxygen, which is used for cutting metals, welding, surface quenching, etc.
Portable homework: It is very convenient to carry calcium carbide and portable generators in places where there is no stable supply of acetylene gas (such as wilderness, construction sites, remote areas).
Specific industrial and chemical synthesis: It is also applied in a few chemical processes that require on-site preparation of acetylene as a raw material.
4. Equipment type
According to the contact and control methods between calcium carbide and water, it is mainly divided into:
Drip type: Water droplets drip into a container containing calcium carbide. The structure is simple and easy to control.
Immersion type: submerge the carbide basket into water. The gas production rate is fast, but the control is slightly more complex.
Drainage type: using the pressure of acetylene gas generated to discharge water, separating calcium carbide from water to stop the reaction. It can automatically adjust pressure and is relatively safe.
5. Advantages and disadvantages
Advantages:
The equipment is relatively simple and the investment cost is low.
The raw material (calcium carbide) is easy to store and transport (safer than high-pressure acetylene cylinders).
Suitable for intermittent and mobile gas demand.
Disadvantages and modern alternatives:
Complicated operation: Regular addition of calcium carbide and cleaning of lime slurry (Ca (OH) ₂ residue) are required.
There are safety hazards: If the design or operation is improper (such as insufficient cooling, leakage, tempering), there is a risk of explosion. Calcium carbide reacts violently with water and needs to be handled with caution.
Gas purity and pressure stability: The generated acetylene may contain impurities such as phosphine and hydrogen sulfide, and the pressure is not as stable as steel cylinders.
Environmental protection issue: It will generate a large amount of alkaline waste residue.
In modern industry, with the maturity and popularization of dissolved acetylene steel cylinder technology (dissolving acetylene in acetone and storing it in porous material steel cylinders), the use of acetylene generators has been significantly reduced. Dissolved acetylene steel cylinders have become the mainstream choice due to their stable pressure, high purity, convenient use, and superior safety. However, acetylene generators still have certain application value in certain specific fields, such as resource limited areas, special processes, or as backup gas sources.
Summary
The main function of an acetylene generator is a chemical device that achieves on-site, safe, and on-demand production of acetylene gas through the reaction of calcium carbide and water. It has been widely used in the field of metal thermal processing. Although its mainstream position has been replaced by safer dissolved acetylene cylinders, its working principle and historical significance are of great importance in industrial development.