Acetylene generator: the device and the principle of operation

The acetylene generator is a device for the production of acetylene by a chemical reaction. The interaction of calcium carbide with water leads to the isolation of the desired product. Currently, such devices are used both in stationary and mobile gas installations. Actually, acetylene is the main fuel in gas welding. Let's talk in more detail about what kind of equipment it is and what its key features are.

Classification of generators

Acetylene generators are usually classified according to several criteria, among them productivity, application, pressure and the principle of action. As for the pressure, we distinguish acetylene generators with low pressure - up to 0.01 MPa, average - 0.07-0.15 MPa, high - more than 0.15 MPa.

By way of movement, the acetylene generator can be stationary and mobile. The latter devices are less productive - 0.3-3 m ³ , stationary produce from 5 to 160 m ^{3 of} combustible gas per hour. As for the principle of action, then it is worth noting the following types: HF - mixing carbide and water, VC - water on CaC ₂ with a possible "wet process". In addition, welders often use the VC, but only with a "dry process". Very rarely, but still combined generators are used. They combine the features and technical characteristics of various species that complement each other.

Principle of action of acetylene generator

As noted above, the design and how the unit works is determined by its type. First, let's look at the "carbide in water" generator. It is the most popular and simple.

The principle of operation is as follows. Carbide through the hopper is supplied in a certain portion to the gas-forming chamber. At this time it passes through the feeder. There is water in the gas-forming chamber. As for the carbide feed, it is automatically controlled and largely depends on the pressure in the system. After the next serving, the pressure in the gas-forming chamber increases. If it falls below the critical mark, the next batch is loaded.

Immediately during the interaction, the same acetylene is formed. It enters a special hose through a selector. Slaked lime is removed through a special bunker.

How does the water-to-carbide generator work?

In this case, we will talk about the so-called "wet process". The principle of operation of such a generator is similar to that described above with only one difference. Here the water is periodically fed to the carbide, from where, in fact, the name went. The obvious advantage of this solution is that with the maximum simplicity of design the reliability of the unit is quite high. Of course, there are some disadvantages here, which are expressed in the incomplete decomposition of calcium carbide, as well as the possible overheating of acetylene due to the insufficient size of the charging device. Such units are very rarely stationary, which is due to their low productivity, which does not exceed 10 m ³ / hour. For example, the acetylene generator of the ASP-10 works exactly according to this principle. It has a light weight of 16.5 kg, and a productivity of 1.5 m ³ / h.

"Water on carbide" by the principle of "dry process"

The essence of the work of such generators is that there is a driving drum with carbide in the gaseous chamber. There is also a semi-automatic carbide feed system. It is loaded into the drum through special hatches. Water is also added here. In this case it is extremely important to observe the correct dosage of the liquid. Its amount should be exactly twice as much as necessary for the breakdown of carbide. Since a lot of heat is released during the chemical reaction, the excess water evaporates, and you do not need to remove them. As for the slaked lime, it falls through the lower grate of the drum, and then it is removed.

In this case, the device of the acetylene generator allows to obtain dry lime due to complete evaporation of the liquid in the system. Hence the name "dry process" actually appeared. As for the advantages of such a solution, they consist in simple maintenance and removal of the spent carbide. Typically, these are stationary-type generators with average performance.

Water Displacement System

The structural difference of such acetylene generators lies in the features of the gas-forming chamber. It consists of two interconnected vessels (propellant and gassing agent). The latter is loaded with carbide, which is why water is displaced into the air cushions of the displacer. Through the selector acetylene is removed from the chamber.

The amount of carbide to be loaded, as well as the performance of the device, are automatically adjusted. True, the process depends on the pressure. The higher it is, the slower it flows, and vice versa. It is interesting that the work of an acetylene generator of this type can be smoothly regulated, which is the strength of the device. Also, the system of "water displacement" is famous for its reliability. The main drawback is that the maintenance of productive plants is very difficult. That's why acetylene generators of this type are made mobile and have a small performance.

Combined Generators

Often, welding equipment combines the "water in carbide" and "water displacement" systems. The principle of operation is that in the gas collection chamber there is a basket with carbide, into which water is supplied. During the chemical reaction, acetylene is formed. If excessive pressure occurs in the system, water is displaced into the air bag of the displacement chamber. The withdrawal of acetylene is carried out through a check valve, after which he leaves the chamber.

In the event of a pressure drop, the water from the displacer flows back to the basket and thereby stimulates the formation of acetylene. For the most part, such systems are manufactured mobile. Combined acetylene generators have high smoothness of operation and absence of such negative factor as pressure drop in the system. Devices have low performance, but are in great demand.

Device of acetylene generator of low pressure

The case of such a device has two separated chambers. Upper - a water collector, lower - a gas collector. Between them they are separated by a special partition. The gas collection chamber has a retort, which is located below. A basket with carbide is placed in it. After loading, it is hermetically sealed, for which rubber pads are used as a sealant.

With the help of a tap, water is supplied from above. When it enters the retort, the carbide process starts, which then goes to the gas collection chamber. Then he goes to the dehumidifier and the water seal, then goes to the cutter or gas burner.

Pressure adjustment is automatic. As it increases, liquid is expelled from the retort. When the water falls below the tap, the formation of acetylene is significantly slowed down. Such welding equipment can work at an ambient temperature of -25 degrees Celsius, which, without doubt, is a virtue.

Generators of medium and high pressure

The acetylene generator ASP-10 refers to equipment operating in the middle pressure range. The device is identical in principle to low-pressure generators. But here - the large dimensions and the corresponding performance. Of the design features it is worth noting the presence of a box through which water flows. In addition, elementary water cooling of acetylene is provided here. This need is due to the high operating pressure and high gas temperature.

Conclusion

So we figured out what an acetylene generator is. The price of such equipment depends on its type. So, ASP-10 will cost about 20 000 rubles. The more productive the unit, the more expensive it is. High-grade fixed high-pressure installations cost from 30 000 rubles and above. When choosing, it is necessary to take into account the temperatures at which the equipment operates. The wider the range, the more universal. In general, this is all the basic information on this topic. Now you know what an acetylene generator is, what kinds of these devices are, what are their constructive and technical differences.