An acetylene generator is a device for producing acetylene by a chemical reaction. The interaction of calcium carbide with water leads to the release of the desired product. Currently, such devices are used both in stationary and in 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 are its key features.
Generator Classification
Acetylene generators are usually classified according to several criteria, including productivity, method of application, pressure and principle of operation. As for pressure, acetylene generators are distinguished with low pressure - up to 0.01 MPa, medium - 0.07-0.15 MPa, high - more than 0.15 MPa.
According to the method of movement, the acetylene generator can be stationary and mobile. The latter devices are less productive - 0.3-3 m 3 , stationary ones produce 5 to 160 m 3 of combustible gas per hour. As for the principle of action, the following types are worth noting here: KB - mixing carbide and water, VK - water on CaC 2 with a possible “wet process”. In addition, welders often use VK, but only with a “dry process”. It is extremely rare, but combined generators are still used. They combine the features and technical characteristics of various types that complement each other.
The principle of operation of the acetylene generator
As noted somewhat above, the design and how the unit works is determined by its type. First, let's look at the carbide into water generator. It is the most popular and simple.
The principle of action is as follows. Carbide through the hopper in a certain portion is fed into the gas-generating chamber. At this time, he passes through the feeder. There is water in the gas chamber. As for the carbide feed, it is automatically regulated and largely depends on the pressure in the system. After supplying the next portion, the pressure in the gas-generating chamber increases. If it falls below a critical level, the next portion is loaded.
Directly during the interaction, the formation of the same acetylene occurs. He enters a special hose through a selector. Slaked lime is removed through a special hopper.
How the water-carbide generator works
In this case, we will talk about the so-called "wet process". The principle of operation of such a generator is similar to the above with the only difference. Here, water is periodically supplied to carbide, from where, in fact, the name came from. A clear advantage of this solution is that with maximum simplicity of design, the reliability of the unit is quite high. Of course, there are also drawbacks, 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 loading device. Such aggregates are very rarely stationary, due to their low productivity, which does not exceed 10 m 3 / h. For example, the acetylene generator ASP-10 works according to this principle. It has a small weight of 16.5 kg, as well as a capacity of 1.5 m 3 / h.
"Water to carbide" on the principle of "dry process"
The essence of the work of such generators is that in the gaseous chamber there is a drive drum with carbide. 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 liquid. Its amount should be exactly two times more than necessary for the decay of carbide. Since a lot of heat is generated during a chemical reaction, the excess water evaporates and you do not need to remove it. As for slaked lime, it falls through the lower grill of the drum, and then is removed.
In this case, the device of the acetylene generator allows you to get dry lime due to the complete evaporation of the liquid in the system. Hence the name “dry process” actually appeared. As for the advantages of this solution, they consist in simple maintenance and removal of spent carbide. Usually these are stationary-type generators with medium capacity.
Water Displacement System
The structural difference between such acetylene generators lies in the features of the gas-generating chamber. It consists of two interconnected vessels (displacer and blowing agent). Carbide is loaded into the latter, which is why water is displaced into the air cushions of the displacer. Acetylene is removed from the chamber through a sampler.
The amount of carbide loaded, as well as the performance of the device are automatically adjusted. True, the process depends on pressure. The higher it is, the slower it flows, and vice versa. It is interesting that the operation of an acetylene generator of this type can be continuously regulated, which is the strength of the device. Also, the “water displacement” system is famous for its reliability. The main disadvantage is that maintenance of production plants is very difficult. That is why acetylene generators of this type are made mobile and have low productivity.
Combined generators
Often, welding equipment combines water-to-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. A chemical reaction produces acetylene. If excessive pressure occurs in the system, water is forced into the air bag of the displacement chamber. Acetylene is removed through a check valve, after which it leaves the chamber.
In case of pressure drop, water from the displacer flows back into the basket and thereby stimulates the formation of acetylene. For the most part, such systems are made mobile. Combined acetylene generators have a high smoothness of operation and the absence of such a negative factor as the pressure drop in the system. The devices have low performance, but are in great demand.
Acetylene low pressure generator
The case of such an apparatus has two separated cameras. The upper one is the water collector, the lower one is the gas collector. Between themselves they are separated by a special partition. The gas collection chamber has a retort, which is located below. A carbide basket is placed in it. After loading, it is hermetically closed, for which use rubber gaskets as a sealant.
Using a tap, water is supplied from above. When it enters the retort, the carbide process is started, which then goes into the gas collection chamber. Then it enters the dehumidifier and the water lock, after which it goes to the torch or gas burner.
Pressure adjustment is automatic. As it increases, fluid is displaced from the retort. When water drops below the tap level, acetylene formation slows down significantly. Such welding equipment is capable of operating at an ambient temperature of -25 degrees Celsius, which, without a doubt, is an advantage.
Medium and high pressure generators
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 - large dimensions and corresponding performance. Of the design features, it is worth noting the presence of a box through which water passes. In addition, elementary water cooling of acetylene is provided here. This need is due to the high working pressure and high gas temperature.
Conclusion
So we figured out what an acetylene generator is. The price of such equipment directly depends on its type. So, ASP-10 will cost about 20,000 rubles. The more productive the unit, the more expensive it is. Full-fledged stationary high-pressure installations cost from 30,000 rubles and above. When choosing, it is necessary to consider at what temperatures the equipment operates. The wider the range, the more versatile it is. In general, this is all the basic information on this topic. Now you know what an acetylene generator is, what types of these devices are, what are their structural and technical differences.