Fan of high pressure of VVD

Effectively working aspiration improves working conditions, raises the fire and explosion safety of production, promote increase in an exit and improvement of quality of products, protect atmospheric air from pollution.

In various industries (for example, in the industry of construction materials, chemical and mining) understand a type of an aerosol, i.e. the disperse system consisting of the small firm particles which are in suspension in the gas environment as dust. In the grain processing industry carry small and easy organic and inorganic firm particles which were allocated to the production room from grain weight when moving, processing and grain processings, and also various loose components of compound feeds to production dust. And carry to dust not only the particles weighed in air (aerosol), but also particles, which settled on the surface of the equipment and building constructions of the building (aero gel). Especially large amount of dust is formed when processing grain in cars of shock action, for example, in oboyechny and vymolny cars, in molotkovy crushers and valtsovy machines. In these cars there can sometimes be increased explosive concentration of dust which eliminate with an equipment aspirirovaniye. Dust, getting through thinnesses of cases of the equipment into room air, increases its dust content, worsens working conditions of the person, reduces labor productivity, increases friction and wear in cars, promotes emergence of the fires, dust explosions, etc. The dust which is in two states: in aerosol (weighed) and in aerogelny (settled), can pass from one state into another. From the first state dust passes into the second under the influence of gravity, and also electric or centrifugal forces. From the second state dust passes into the first under the influence of the revolting forces caused by vibration, blows or streams of air. The composition of dust depends on its origin. Industrial dust consists of the same products and substances which overwork at this enterprise. Grain dust consists of two parts: mineral and organic. On elevators dust contains up to 50% of mineral particles. In zernoochistitelny offices of the flour-grinding plants and krupozavod organic dust prevails (to 80 … 95%). In razmolny and vyboyny offices of the flour-grinding plants all dust flour, an organic origin. At the enterprises for storage and grain processing dust on value can be unusable (black) an ash-content more than 6,5% (is liable to destruction) - fodder (gray) an ash-content 2 … 6,5% (can go on a forage to the cattle and to a bird) - food flour (white) an ash-content less than 2% (it is used as foodstuff at production of flour of the second grade). The sizes of particles fluctuate over a wide range - from micrometer shares to 250 microns. Depending on the sizes of particles dust conditionally divide on large (50 … 250 microns), average (10 … 50 microns) and small (it is less than 10 microns). On elevators and warehouses for grain large dust, in zernoochistitelny offices of the flour-grinding plants and krupozavoda - average dust, in razmolny and vyboyny offices of the flour-grinding plants - fine dust (70-80% with a size of particles less than 3 microns), in shelushilny offices of krupozavod and on formula-feed plants - also fine dust prevails. Harm of dust depends on its sizes and the chemical composition. Large dust is less dangerous, than small as she lingers at breath on mucous membranes of a nose. Fine dust with a size of particles 5 … 10 microns - the most hazardous to health of the person. The chemical composition of dust more defines its harm which is estimated on the content of dioxide of silicon (silicon dioxide). Purity of air in working rooms has to be maintained on dust content at the level which is not exceeding the threshold limit values (TLV): 4 mg/m3 of grain dust and 6mg/m3 flour. In places of full-time residence of people dust content of air should not exceed 0,5mg/m3 irrespective of a type of dust. Admissible concentration of dust at emission of air in the atmosphere after sedums in aspiration and pneumotransport installations is defined by air dispersion calculation. One of the main objectives, solvable by means of ventilating and aspiration installations, - ensuring purity of air on the dust content which is not exceeding these limits. Purity of air in working rooms (on dust content) can be provided with aspiration installations by means of effective aspiration of all equipment in which dust is formed. Purity of the air released into the atmosphere can be provided including use of highly effective dust collectors (it is desirable filters).