Preventing dust adhesion

What is dust adhesion

Dust adhesion is the process in which dust particles are attracted towards a certain surface due to physical forces such as “diffusion, mechanical interaction or electrostatic attraction”. Environmental dust and dust combined with other compounds create industrial issues. The gravity of these issues varies; however, they shouldn’t be neglected as they can worsen. Furthermore, these are the most common issues related to dust adhesion:

• Dust related defects
• Costs of repairs (time, manpower, and infrastructure)
• Decrease productivity

Selecting the proper solutions and equipment for dust mitigation

What materials and solutions assist in repelling dust?

Dust adhesion has a critical impact on the industrial field as it affects the people, the processes involved, the machineries and the final product. The elimination of dust within the industrial field is still a work in progress, as currently there are ways that can assist in minimizing it. Researchers are investigating over various materials and chemical solutions that aid in efficiently repelling dust from adhering to a particular surface

In multiple academical studies, the adhesion of dust on hydrophobic surfaces and on hydrophilic surfaces under sonic excitations and vibrational excitations have been investigated.

Before explaining the results of these studies, we can emphasize over the definitions of hydrophobic and hydrophilic. Hydrophobicity can be defined as a molecule or a particle that has the physical properties of being repelled from water.

On the other hand, hydrophilicity is a molecule or a substance that is soluble and can dissolve into water.

To begin with, depending on their size dust particles can be repelled by hydrophobic surface dust as the adhesion forces are minimized up to 47 %. The size distribution of dust particles varies; however, the average size of a dust particle is about 1.2 µm (microns). This result was provided under a sonic excitation frequency of 64 Hz.

Moreover, it has been demonstrated that sonic excitation assists in mitigating dust with the right selection of frequency and distance of excitation. This has been made possible my measuring the inflight of dust particles displacement on both vertical and horizontal axes. For example, when the excitation is set for a frequency of 75 Hz, can repel dust from surfaces from longer distances thanks to the low inertia force of the dust particles. Thus, the amount of dust residues that remained on hydrophobic surfaces was considerably low, however it is more effective on inclined surfaces.

(To read the full study on sonic excitation and check for the in-depth information, click here.)

Under the microscope, a micrograph of dust residue presented itself with sharp edges which makes it more prone to stick to surfaces that are coated. Moreover, the residues tend to bundle, impeding the repellent action of a vibrational excitation. However, in the case of vibrational excitation, it has been demonstrated that applying a frequency of 30 Hz is efficient for both type of surfaces, hydrophobic and hydrophilic, in repelling dust particles.

Moreover, the angle inclination augments the ability of the dust to be repelled.  In terms of adhesion force of the dust particle, the results have shown that they are more repelled on hydrophobic surfaces than hydrophilic surfaces. By being more attracted to adhere to hydrophilic surfaces, this lowers the velocity of dust clusters.

(To read the full study on vibrational excitation and check for the in-depth information, click here.)

In a different study, environmental dust was tested to observe their adherence levels from various surfaces. The dust particles were mixed with a modified chemical solution and analyzed on both hydrophilic and hydrophobic surfaces of glass. Moreover, after a microscopic analysis, it has been encountered that the environmental dust structure contains various particles and elements, and some of these elements do not meet the stoichiometric ratio, as it causes cationic or anionic reaction. This leads to the accumulation and creation of dust clusters. Based on the applied solution, a low concentration hydrofluoric acid, it appears to combat and decrease this effect of dust cluster forming.

Furthermore, this applied solution resulted in the reduction of the development of dust adhesion and dust clustering on both hydrophilic and hydrophobic type of surfaces. For this case as well, the inclined axial tilt assists into easily cleaning the glass surface of the solution mixed dust as opposed to the regular environmental dust, thanks to the gravity forces.

(If you want to read more and the discover the methods and in-depth experiments that were conducted during this study, click here.)

Stopping dust adhesion is a two-step process consisting of reducing the number of dust particles and neutralizing the remaining particles. Neutralization is achieved through humidification and dust suppression.

• Humidification: Dust sticks to an object due to its micro-structure, the viscosity or by an electrostatic charge. By controlling the relative humidity, the conductivity of the air is increased preventing dust from sticking to an object due to an electrostatic charge.
• Dust suppression: In facilities other than clean rooms, airborne dust is impossible to avoid, even when using over-pressure. By spraying a non-wetting water droplet that is the same size as the dust particles, we can suppress the dust particles and avoid these particles from reaching specified objects.

Examples of Systems / Products used for this application

AirAKI^® – Industrial humidification system, it sprays Dry Fog with an average droplet size of 10μm or less. The AirAKI® system with the Dry Fog humidifier AKIMist®”E” has the capability of combating even the most minuscule dust particles. Besides humidification and dust suppression, the AirAKI® system can also assist with the cooling factor within a particular enclosed environment. While this product can be implemented in multiple industry thanks to the innovative design, we do advise consulting with our specialists for a proper technical analysis and recommendation.

BIM series – Pneumatic nozzle, BIM nozzles produce extremely fine droplets ranging from 10 to 100 μm. We can adapt to a wide range of operating conditions. Their spraying provides a fine atomization that assist with cooling and humidification. Moreover, their engineering mechanism is fabricated in such a way that they are clog resistant. The series provides a range of nozzles with various types of patterns, such as: flat, hollow cone and full cone. Attached to a compressed air system, their spraying can be easily controlled, and they offer the possibility of regulation with an on/off switch provided by a controlling adaptor.

Hydraulic systems with hollow cone spray pattern nozzle – For preventing dust adhesion, our hollow cone series (KB, KBN, LYOHM unit) sprays extremely fine fog and ultra-small capacity without using air. These nozzles are recommended as they have the finest atomization amongst all hydraulic nozzles. These series have a high-wear resistance that is provided thanks to their ceramic tip. Moreover, they are applicable for humidification, cooling and dust suppression amongst others.

Benefits

• Prevent dust adhesion
• Suppress airborne dust particles
• Preventing static electricity
• Regulate humidity in confined spaces
• Ambient cooling
• Employee wellbeing

Preventing dust adhesion in specific industries

In certain industries, dust adhesion is developed faster as a consequence of the industrial field processes. For example, in environments such as garbage plants, iron/steel plants, recycling plants, cement plants, dust disperses and spreads faster, affecting both the wellbeing of the workers decelerating and affecting the efficiency of these working processes.

If you want to retrieve more information regarding the products that are offered as solutions for dust adhesion, entering on the product page can be the first step. There you can find technical data regarding these products as well as an individual product catalog that you can download. We made it easy and accessible for your experience. However, for any question or query, you can always contact our specialists and they can advise you and provide you with their know-how.

At IKEUCHI, we have determined the fundamentals to select the right nozzle for your application based on their characteristics. When selecting the nozzle, we advise you based on your required spray angle, spray capacity, optimum spray pattern, and spray distribution.

If you have technical question about nozzles, need advice to choose, or request a quote,

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