Dust control machine
A device for binding dust particles in non-guided air is called a dust binding machine . This can be stationary z. B. can be attached to buildings or placed on the move and works on the principle of dust binding through the finest drops of water.
Intended use
Dust can have various negative influences on people and cause numerous diseases of the respiratory system. Therefore, industrial polluters are increasingly asked to reduce their dust emissions u. a. to reduce by means of suitable measures Dust-binding machines are therefore used in companies where dust-laden air cannot be captured in any other way. These are typically material handling points, construction sites, recycling yards, quarries, mines, steel and cement works.
technology
Similar to gas scrubbers , a large number of tiny droplets are generated that are brought into contact with the dust-laden air. If a dust particle comes into contact with a water droplet, it is bound to the water droplet and deposited. By adding an agent that reduces the surface tension of the water, the wettability of the water droplets can be increased. If the dust particle is easily wettable, it is incorporated into the interior of the drop.
The size of the water droplets is an important criterion for the quality of the dust binding. Small water droplets bind the dust very reliably because, in addition to their larger number and homogeneous size, they stay longer in the air due to the lower flight and fall speed. This creates less suction around the drops, which means that they often combine with dust particles. Due to their mass, large drops (> 1 mm) can be shot further and more precisely at a source of dust, but the high sinking speed and the resulting suction effect around the drops prevent a good dust-binding effect in the air. For this reason, large drops are mainly used where it is a matter of keeping the dust on the ground by moistening or preventing it from z. B. rises into the air by wind.
One-substance and two-substance systems are used in dust-binding machines. In single-substance systems, water is atomized through special nozzles at a pressure of 3 bar to 5 bar. The atomization takes place solely due to the water pressure and the nozzle geometry. In two-substance systems, water is atomized using compressed air. The water consumption in two-component systems is just as lower as the droplet diameter achieved. Single-substance systems do not require compressed air for this and can be used where it is not available.
Modern systems for binding dust generate a constant water mist with a large number of tiny water droplets using a medium or high pressure pump (from 20 bar) and suitable nozzles. In the swiveling conical cylindrical head of the machine, a high-performance fan generates an air stream that blows the droplets onto the source of dust to be combated, with the aim that the droplets combine with the dust particles and let them sink to the ground.
The degree of separation of dust-binding machines cannot be determined in a generally valid way. In particular, wind influences can reduce the cleaning result. However, dust binding machines have the positive side effect that by wetting potentially dusty surfaces, the entry of dust from driveways or dumps into the atmosphere is reduced by turbulence or drifts.
Individual evidence
- ↑ New design for the quietest dust-binding machine in the world. In: Hazardous substances - cleanliness. Air . 79, No. 6, 2019, ISSN 0949-8036 , p. 240.
- ↑ Ulrich Klenk, Eberhard Schmidt : Use of water mist to reduce airborne fine dust. In: Hazardous substances - cleanliness. Air. 68, No. 1/2, 2008, ISSN 0949-8036 , pp. 43-45.
- ↑ a b c d VDI 2095 sheet 1: 2011-03 emission reduction; Treatment of mineral construction and demolition waste; Stationary and mobile demolition waste recycling facilities (Emission control; Treatment of mineral construction-site and demolition waste; Stationary and mobile demolition waste recycling facilities). Beuth Verlag, Berlin. Pp. 26-27.
- ↑ Ekkehard Weber: Status and goal of basic research in wet dedusting. In: Dust - cleanliness. Air . 29, No. 7, 1969, ISSN 0949-8036 , pp. 272-277.
- ↑ Dust binding. FRUTIGER Company AG, accessed on April 12, 2016 .
- ↑ Ulrich Klenk: Use of spray nozzles with water and additives to reduce diffuse dust emissions. In: Hazardous substances - cleanliness. Air. 72, No. 11/12, 2012, ISSN 0949-8036 , pp. 498-502.