The operation of water heating systems with branched pipelines is accompanied by numerous problems associated with the need for maintenance of communications. The user has to monitor the quality of tightness, control the integrity of the connections, fix violations in the operation of measuring devices, etc. Of course, preventing negative factors in the operation of a heating network is a more reasonable approach than dealing with their consequences. And one of the main issues of preventive maintenance is the following: how to expel air from the heating system that has accumulated in the pipeline and adjacent communications?
Causes of airing the heating system
Strictly speaking, the presence of air in pipelines in itself is a normal and natural phenomenon. The only question is the reasons for its entry into the heating circuits and volumes. How to determine the limit of the norm,will be discussed below, but for now it is necessary to understand the conditions under which, in principle, excessive airing is possible. First, air is present in the coolant distribution channels initially. A competent team of installers, already before putting the system into operation, must correctly organize the primary bleed operation, during which the necessary balance of the gas content in the water will be ensured. How to remove air from the heating system in the first stage? This is done through special channels in the collectors, flow control systems and through some models of circulation pumps. Secondly, already during operation, air naturally enters the coolant distribution circuits through process equipment - an expansion tank, boiler equipment, heaters, devices for measuring coolant indicators, etc.
But even if all connections, gaskets and seals are in good condition, a certain amount of air will still enter the system, requiring periodic or constant de-airing. Now it is worth turning to cases where this problem should be given special attention.
Signs of airing
The accumulation of air in different parts of the pipeline network and in the heating equipment itself makes itself felt by the following effects:
- Vibrations - in pipes and structures of heating devices.
- Noise - typically related to radiators, but can be heard from areas where long piping lines are locatedhum.
- Decrease in equipment performance. It is reflected both in the drop in power and in the physical sensation of a decrease in the thermal efficiency of the units with respect to temperature.
As soon as such signs are fixed, the question should be raised about how to expel air from the heating system and eliminate the negative consequences of this phenomenon. This can be done in many ways, but first it would not be superfluous to fix the risks that inaction in such situations may entail.
How dangerous is the air in engineering networks?
If for one reason or another the signs of airing were ignored, then after a while you may encounter processes of destruction of the technical heating infrastructure. The formation of air pockets leads to an uneven distribution of the coolant, which threatens not only with a significant decrease in thermal power, but also with a harmful effect on parts of the equipment structure. Often such plugs form in the corners of radiators or standard batteries. If air is not removed from the heating system in a timely manner, then oxygen in the accumulated gas mixture will create conditions for oxidation, followed by the formation of corrosion. The situation is complicated by the fact that rust corrodes the metal from the inside without visible external traces. Obvious breakdowns of parts of heating structures and pipelines will make themselves felt by breakthroughs and depressurization of entire circuits.
How to identify air pockets?
To effectively solve the problem of airing, it is not enough to know what is insystem contains air in undesirable volumes. It is also necessary to determine the areas of accumulation of the gas mixture and the points of the most favorable flow bleed. How to properly expel air from the heating system so as not to disrupt the overall performance of the network? Typically, engineering networks are designed with the expectation of air outlet in the uppermost nodes - these are the most convenient places for bleed, work with which also does not affect the functioning of the circuits. In essence, these are the nodes of the natural removal of unwanted components in the coolant flow. As for the accumulation of bubbles in batteries and radiators, you can use the old folk method of tapping. According to the characteristic sonorous response, it will be clear that there is a void inside the site. By the way, aluminum radiators are more prone to airing, so such designs should be "emptied" regularly.
How to deal with the airing of heating circuits?
Different methods are used to remove air mass from the pipeline, most of which are specialized solutions. In particular, air bleeding in domestic heating systems is carried out through outlet cocks of various designs. For example, how to expel air from the heating system at home without special equipment? To do this, an air vent is initially installed in certain places and with its help the user can independently solve the problem. Another thing is that shut-off valves of this type have many options for execution and in each case there are specific technical features.bleed air.
Bleeding air through the radiator and expansion tank
The main group of ways to release air, if we are talking about the simplest systems with natural circulation of the coolant. The absence of circulation equipment simplifies the network infrastructure and, in principle, reduces the risk of air locks - nevertheless, it is necessary to bleed excess gas mixtures in such systems. So, how to expel air from the heating system with the natural movement of hot streams? This is done through radiators, an expansion tank or other end equipment, in the design of which valves are provided. The main thing is that the location of the conditional tap is at the top point, so that it is the air that comes out first. The disadvantage of such methods is the locality and the impossibility of deairing the entire system through one specific point of release.
Use of Mayevsky crane
Entry level dedicated air exhaust solution. This is a manual faucet, which is usually built into a pipeline branch along with a circulation pump. That is, the method is suitable for systems with forced movement of the coolant. How to expel air from the heating system using a Mayevsky tap? First of all, the circulation of flows is turned off, after which the tap should be slightly unscrewed with a screwdriver. As it is unscrewed, a hissing sound will begin to be heard from the nearest exit point. This suggests that under the force of pressure, the air began to descend outward. Once through the faucetwater will also begin to flow abundantly, you can close it.
Using the automatic air vent
A very convenient solution for removing air masses for those who do not want to periodically perform this operation manually. The principle of operation of this air vent is based on the creation of a constant channel for the outlet of gas mixtures, which is regulated by the pressure in the circuit. As soon as a sufficient amount of bubbles accumulate on the back of the valve, a special float drops and thereby opens the air release valve. But such devices have one big drawback, which is associated with the contamination of the coolant. How to bleed air from the heating system using a constantly operating automatic valve without negative sanitary and hygienic factors? This problem is especially relevant in residential areas where the same radiators work. And the answer in this case is the same - to use models with additional functionality that can perform the tasks of filtering, cooling and conditioning streams.
Use of air separators
In a way, the opposite of the above-described air vent, although in principle the same tasks are solved. Separators for air removal are mounted in the circuits of the main networks. They are designed to separate flows into air, liquid and solid phases. How to bleed air from the heating system in this case? To do this, it is enough to install a bypass node on the pipeline line and build it intoseparation block, which is a grate with a metal cylinder. During the passage of water through this device, air bubbles are caught from the stream, followed by discharge into the air intake. Also, delayed sludge and other foreign solid inclusions of different fractions are sent to another outlet channel.
How to expel air in a closed heating system?
Ultimately sealed circuits, by definition, provide less room for air pockets to form, but the same technical barrier makes it difficult to bleed air when gas buildup does reach a critical level. How to be in such a situation? How to remove air in a closed heating system without changing its design and maintaining its current performance? The only way out in this case will be directly the contour of the movement of water, so the user's task is to create natural conditions for the air masses to leave along with the fluid flows. This can be achieved by heating the water in the problematic circuit to about 95-100 ° C. This is not a critical mode for the infrastructure designed for the heating function, but it will also stimulate the process of air bubbles release and its removal along with the coolant through the direct circulation channel.
Multi-stage approach to problem solving
Even in small domestic heating systems, it is not always possible to limit one of the above methods to the use if there is a clear task of a stable air outlet. Therefore, experts advise considering an integrated model for removing air from a heating system with several bleed points. For example, it is recommended to install an automatic air vent on the boiler, Mayevsky taps - in the design of radiators, manual air vents work well in collector systems, and separators with filters are suitable for main networks and risers.
Conclusion
The task of eliminating air masses from the heating pipeline is quite solvable, however, it will be possible to achieve a good result without negative factors only with a thorough analysis of the technical side of the issue. A lot in this matter also depends on the characteristics of a particular heat supply device. If we constantly bleed air from a heating system with an improperly organized circuit distribution scheme, then after a while we can expect an accident in the network, even if a high-quality air vent is working. For example, an excessive slope in a pipeline can create a natural environment for continual accumulation of plugs in a short period of time. It is possible to provide such a site with an automatic air vent, but the cause of the problem will remain unresolved, and regular air circulation during this time will provoke irreversible corrosion processes.
