The production of many types of products is associated with the formation of dust suspensions that prevent workers from breathing and threaten their health. Cement plants, crushers, mills, enterprises of the chemical, metallurgical industry and many other economic sectors faced the problem of clean air in the shops immediately after their appearance.
They tried to fight dust and other dangerous pollution by issuing personal protective equipment (called respirators and which are simple respiratory filters), but they were not very effective. In recent decades, a more effective means for creating normal working conditions - aspiration - has become increasingly popular in developed production companies. This word has a Latin root “spiro” in common with a respirator, meaning “breath”.
The task of the suction system
At the mentioned enterprises, referred to as hazardous production, it is impossible to work without ventilation. Various airborne hazardous and unpleasant impurities leave the enclosed enclosed space with removed air. Actually, it was this fact that inspired the engineers to increase the degree of purification, creating the most favorable conditions for the passage of the dust-air mixture.
An aspiration system is a combination of technical means that ensures the removal of suspended impurities from the working areas of industrial premises in order to reduce their concentration and impact on the human body, as well as their disposal. In other words, it is created so that people can breathe easily, and the factory or plant does not harm the environment.
Suction system pipe and fan
The most important thing in this system is the pipe. But not simple, but special, made so that the dust in it does not get stuck and does not accumulate. It is quite possible to use longitudinal pipes, but spiral-wound pipes similar to hoses of vacuum cleaners perform their function better. But the subtleties do not end there: the slope of the duct also matters. Dust is very heavy (for example, cement), so the design of aspiration is carried out taking into account the specific nature of the impurities, their physical and chemical properties. The gasket scheme is most often branched, has turns characterized by a value of relative rounding, the radius of which should be at least twice the diameter of the pipe.
The pressure gradient at the inlet-intake and outlet can be created by a level difference, but the fan nevertheless gives the required flow rate, without which high-quality aspiration is impossible. This, as a rule, is a classic "snail" of low pressure (sometimes there are several of them).
Waste treatment
What to do with polluted air? Just throwing it into the atmosphere is not only unethical in relation to residents of adjacent urban or rural areas, but also fraught with impressive amounts of fines imposed on industries whose management does not want to treat the environment with due respect. Therefore, it makes direct sense to separate harmful inclusions. This problem is solved by two devices connected in series in the pipeline - a separator and a filter.
The collected "garbage" in some cases can be used for recycling, but even then its volume should be reduced, so it is pressed and collected in special containers.
So, if the air purification system consists of a pipeline, a pump, a separator, a filter and a collection of recyclable waste, then this is aspiration. Ventilation is only part of it, providing pneumatic transportation of the air-dust mixture.
Monoblock suction systems
Despite the simplicity of the principle of action, there are various ways of its implementation. The most widespread monoblock scheme, in which at every workplace polluting the air, dust removal devices are installed. They are stationary or mobile. Such aspiration is an analogue of the already mentioned vacuum cleaner with its own hopper, subject to regular cleaning, its own fan (air pump) and a short duct, which, depending on the degree of mobility, is a flexible hose or a rigidly installed pipe. Monoblocks are produced in series, which is due to their relatively low cost.
Modular systems
Large-scale production with a high dustiness of workspaces with monoblock suction devices cannot do. High productivity is required with ease of maintenance, because the constant need to clean a large number of small containers is too time-consuming. In this case, a typical approach is very rare, except that the production cycle itself is standardized, and it provides for such an important system as aspiration at the design stage. This happens when a mill or plant of a certain type is turnkey and meets the highest environmental standards. More often, companies involved in solving the problem of air pollution in the working area participate in the modernization of long-running production facilities that require individual study of all technological aspects.