The catalyst is ... The automobile catalyst and its role in the exhaust system
A catalyst is a device with a simple design, but its role is large enough. As a result of the operation of internal combustion engines, a mass of harmful substances is formed, which are emitted into the atmosphere through the outlet path. Catalytic converter reduces exhaust emissions.
History of creation and implementation
In the 60s, the government bodies of all developed countries of the world decided to pay special attention to emissions from the exhaust pipes of cars, because the law did not regulate the pollution of the atmosphere by cars.
In 1970, they adopted the first standards, which were presented to automobile plants. They contained instructions on the content of harmful substances in the exhaust gases. These standards required that automobiles use converters that would neutralize the harmful effects of carbon monoxide and hydrocarbons. In 1975, the use of catalysts became mandatory.
Neutralizers for toxic gases
Every day more and more cars appear on the roads. The car is a powerful source of polluting the atmosphere. Especially filled with gases, the air in large cities and cities.
Constantly all new and new laws are issued, which should limit the permissible levels of emissions of gases during the operation of the internal combustion engine. Car manufacturers are trying to meet these standards, therefore, constantly improve the fuel and exhaust systems, as well as change the design of the engine.
Little about emissions
To make the amount of emissions into the atmosphere as low as possible, modern internal combustion engines constantly and very carefully control the fuel that burns in them. This is to ensure that the air-fuel mixture is ideal. At this ratio, the fuel must burn along with all the oxygen in the air. When driving a car, this ratio is not perfect. Sometimes the mixture is poor, sometimes more enriched.
Today, the main air pollutants consider nitrogen in the gaseous state (N2), carbon dioxide (CO2), and water vapor.
If we consider in essence, these products of combustion are not dangerous. But scientists believe that carbon dioxide affects global warming. As a result of the imperfect combustion of fuel and air, a small amount of especially harmful gases and substances is released. It was for them that these devices were created. Carbon monoxide, various hydrocarbons, oxides of nitrogen can be considered as especially hazardous substances.
The principle of the catalysts
If you recall a school chemistry course, then a catalyst is a special substance that allows you to speed up a chemical reaction or cause it. At the same time, it will not be in the reaction products. It simply participates in the process, but is not in itself a reagent or product.
In neutralizers or converters that are installed in cars, there are two types of catalysts. It is reducing and oxidizing. Both are made of ceramic, which is coated with metals. Basically, platinum or rhodium is used as metals. The idea here is to create such a structure that, when passing exhaust gases through it, involves the maximum area, and the amount of catalyzing substances should be minimal, since their price is quite high.
Some converters use gold with various traditional impurities. It can increase the degree of oxidation. This is necessary in order to reduce emissions of harmful gases.
Types of converters
Many modern exhaust and exhaust systems are equipped with two types of converter converters. That is, for each substance to have its own element, which will minimize the release.
The regenerating catalyst is the very first stage of the neutralization and conversion process. Here in the composition most often the homeland, as well as platinum. It is designed to neutralize nitric oxide in exhaust gases. As a result, oxygen and nitrogen are formed.
The oxidizing converter is the second in this chain. It is designed to reduce the amount of unburned fuel, as well as reduce the amount of carbon monoxide. As a result of this converter, CO2 (carbon dioxide) is formed.
As for the designs of these devices, there are "honeycombs" and "ceramic beads". In modern cars, cellular structures are more common.
In AvtoVAZ cars, a ceramic structure coated with platinum or palladium is used as a neutralizer.The recovery converter on most models uses rhodium and platinum as neutralizing agents.
People especially like these devices. Firstly, this thing is quite expensive, and secondly, in our country due to low-quality fuel converters often fail. Someone replaces them, and someone uses catalysts-flame arresters.
This is a substitute for the neutralizer. The main task that is put before him is the alignment of the exhaust flow. Thanks to him, the work of the exhaust system becomes more correct and durable. Through the use of these designs, you can add power to the car, and the sound of the motor will be even.
The main difference is that the flame arrester does not know how to neutralize harmful emissions. However, as evidenced by domestic standards, the exhaust completely any foreign cars are much lower than permissible. Today, many in their cars change the catalyst (Ford Mondeo is most often exposed to this) to flame arresters. It is believed that with these devices, the engine breathes better.
Device flame arresters
The design is similar to conventional resonators.Therefore, in European countries, this concept does not exist. This node is called not only as a preliminary resonator.
There are direct-flow flame arresters and devices with a diffuser. The latter is called the funnel, which is welded to the pipe in its middle. She forcibly pushes exhaust fumes into a flame arrester.
Catalyst replacement issues
Sometimes on domestic cars, and on foreign cars, there is a need to replace the neutralizer. For example, the catalyst of the 2114 VAZ significantly improves the dynamics of the car, and also reduces fuel consumption.
The need to replace this part of the exhaust system comes only in two cases. It is believed that such an element takes a part of the power of the car. However, increasing power in this way is a very dubious event.
In the second case, the item would fail. This happens if you often fill the car with low-quality fuel. It also happens with some engine malfunctions that lead to oil consumption and blockage. Repair of the catalyst is necessary if there were mechanical damage on its body. In addition, the transducer may become unusable due to the ingress of silicone. Another replacement is required in case of overheating.If the device has heated over 970 degrees, then definitely need to be changed.
How to check the catalyst?
If you notice that the car moves to a certain speed with great difficulty, and then it works normally, or if the speed capabilities of the car gradually decrease, or your motor does not start at all, then you will face the repair of the catalyst.
To check this part, it is necessary to dismantle and inspect it in the light. Another way is to check the pressure in the exhaust system. To do this, it is necessary to install a pressure gauge in place of the oxygen sensor and take readings.
These devices are designed to neutralize the toxicity of the exhaust gases of the car, as well as to make the engine more quiet. Sometimes the neutralizer fails and it needs to be replaced. Since these parts are not cheap, then motorists are looking for compromises.
To solve the problem with this part, sometimes motorists use so-called emulators. There are two types of these devices, one of them is mechanical, the second is electronic.
Mechanical snag catalyst is a bronze or any other metal part that withstands high temperatures. It should be borne in mind that the size of the snag must match the size of the transducer.Where the emulator should be fixed, you need to drill holes for the supply of gases. In the cavity of the emulator there is a crumb of ceramics, which is covered with a catalytic substance.
It is impossible to make an electronic device yourself, but it costs much less than a regular catalyst (the price is quite substantial here).
Automotive stores offer fairly sophisticated models, but this is a special emulator equipped with a microprocessor. It makes the control unit work properly. There is no deception here.
The catalyst is an important part of the design of many modern cars. The main purpose of this device is to neutralize harmful emissions into the atmosphere. This part cannot serve forever, so sooner or later it will have to be changed.
Today in the automotive markets you can buy a catalyst (the price will be from 4,000 rubles and more) for domestic cars. For example, an original spare part for a VAZ car costs about 5,160 rubles. The cost of replacing this part on some foreign cars can cost 2400 rubles or more,but you can change this element in your own garage, with your own hands. This operation does not require much effort and special tools.
So, we found out what an automobile catalyst is, what it is used for and what its cost is. The choice is yours!