HAVA FİLTRASYONU

CHARACTERISTICS OF THE AIR WE BREATHE

The air we breathe; It also includes matter particles and gases formed as a result of nature, humans and industrial processes. Among these, the particles and gases we need to pay attention to are; These are the ones that harm our health, comfort, the spaces we live in and the products we produce.

 

1. Various gases, water vapor, carbon dioxide, methane, carbon monoxide, ozone, ammonia, nitrogen oxides and hydrogen sulfide.

    

2. Small amounts of argon, neon, helium, krypton, hydrogen and xenon.

    

3. Atmospheric pollutants, volcanic ash, sea salt, dust, sand, pollen, mold and bacterial spores.

POLLUTANTS IN THE AIR

We can divide air pollutants into three groups:

The first group includes dust and smoke. This category includes siliceous minerals, sand, natural and synthetic fibers, and carbon. Free carbon is found in soot, soot, ash and smoke. Carbon is the most polluting element in nature. One thimble of carbon black can be enough to contaminate 4000 m2 of white paper.

It is possible to encounter combined carbon in the form of decayed animal and plant remains, seeds, pollen and many other forms.

The second group of pollutants are liquid particles that appear as clouds and fog.

The last group is the pollutants formed by particles that are not gases or solids.

 

DIFFERENT PARTICLE SIZES

Particles vary in size depending on the manufacturing source. Different particle sizes are shown in the figure below.

EFFECTS OF PARTICLES ON HUMAN HEALTH

Particles smaller than 10 microns can cause respiratory system problems in humans. A healthy human body can filter particles smaller than 3-5 microns with the help of the respiratory system. Exposure to particles smaller than this size may pose health risks to humans.

Diseases are transmitted from person to person through direct contact or through the air. Airborne transmission occurs by inhalation of very light particles and aerosols of 1-5 micron size suspended in the air. Bacteria, molds and viruses that cause infection are carried in the air by adhering to organic and inorganic dust particles such as soot, skin cells and aerosol droplets. Particles of this size easily reach the lungs through breathing and accumulate there, and when they find a defenseless body, they can defeat the immune system and cause disease.

FILTRATION

Filtration is a process used to remove unwanted particles or contaminants as they pass through a substance (usually a liquid or gas). The air filter cleans the air by trapping solid particles, pollen, dust, germs and other pollutants in the air.

Air usually goes through several steps as it is filtered:

 

PRE-FILTRATION (GROV- ROUGH)

In this step, larger particles are filtered out. Pre-filters are often called grov filters and are used to prevent large particles from clogging other filters. Class G filters generally refer to filters that capture larger particles and are generally used as the first stage in air filtration. Generally, class G filters are considered filters that can capture particles of 10 microns and larger. This indicates that they are used as a first stage to retain larger particles and prevent clogging of finer filters.

MEDIUM-FINE FILTRATION

Medium or fine air filters are designed to capture particles typically between 1 and 10 microns in size. These filters are usually located between the first stage (usually grov filtration) and the second stage (usually fine filtration) and generally provide a transition between grov filters that can capture larger particles and filters that can perform finer filtration.

Medium air filters refer to filters that can effectively capture medium-sized particles present in the air flow. These filters are usually made of fiberglass, polyester, or other synthetic materials and are often used in ventilation systems, air conditioning systems, industrial processes, medical devices, and similar applications.

Particles 1 to 10 microns in size generally include medium-sized pollutants such as dust, pollen, wood chips, insects, fungal spores, and more. Medium air filters clean the air by capturing such particles and generally improve indoor air quality.

 

Classification of Filters According to EN 779:2012 Standard

ABSOLUTE FILTRATION (HEPA-ULPA)

HEPA (High Efficiency Particulate Air) filters are known as high-efficiency particulate air filters and are capable of capturing very small particles (usually those 0.3 microns in size or larger).  The most important feature of HEPA filters is that they have the capacity to capture very small particles at an extremely high rate. A typical HEPA filter can capture particles as small as 0.3 microns with an efficiency of 99.97% or higher. This represents a filtering capacity that can effectively capture both larger and smaller particles.

Generally, HEPA filters are made of microfiber materials such as fiberglass or synthetic fibers. The properties of these materials are optimized to provide the ability to capture high amounts of particles. Typically, HEPA filters have a layered structure. These layers ensure that particles are captured as they pass through the filter while optimizing airflow. Filters usually come in the form of plates, folded packages or rolls.

HEPA filters are used in many industrial, commercial and medical applications. They are widely used in areas such as hospital sterilization, pharmaceutical production, laboratories, high-precision manufacturing facilities and air purification systems.

HEPA filters improve indoor air quality by capturing harmful particles in the air and play an important role in many applications. These filters are critical for health, safety and environmental protection.

HEPA Filter Structure

HEPA Filter Structure

Classification of Absolute Filters According to TS EN 1822 Standard

GAS FILTRATION

Gas filtration is a process used to remove gaseous contaminants or particles as they pass through a substance. Gas filtration is usually achieved through specially designed gas filters.

 

Filter Material Selection: Filters used in gas filtration are made of special materials that can effectively capture gaseous pollutants or particles. These materials are generally activated carbon, zeolite, alumina or similar absorbent materials.

 

Filtering Process: As the gas passes through the gas filter, the filter material captures the contaminants or particles in the gas. This process is accomplished by a large area of ​​the inner surface of the filter material, so more pollutants can be captured.

 

Adsorption and Absorption: Gas filters can attract contaminants (adsorption) or chemically retain them (absorption). For example, activated carbon filters adsorb and remove organic compounds from the gas, while alumina filters can absorb certain chemicals, such as acid gases.

 

Filtering Efficiency: Filtering efficiency varies depending on the type of filter material used, the design of the filtering process, and the requirements of the application. For more effective filtration, the design of the filtration process and the materials used must be carefully selected.

 

Maintenance and Replacement: Gas filters require regular maintenance and periodic replacement. Filter material can become saturated or clogged over time, reducing filtration efficiency. Therefore, it is important to check filters regularly and replace them if necessary.

 

GEL FILTRATION

Gel air filters are a type of air filter used to remove airborne microorganisms and other microbial contaminants. These filters usually contain a polymeric gel matrix and trap airborne microorganisms within this gel.

 

Polymeric Gel Matrix: The microbial gel air filter usually contains a polymeric gel matrix. This gel matrix is ​​full of pores in which microorganisms are trapped and trapped.

 

Microorganism Entrapment: Airborne microorganisms are trapped within the gel through pores in the filter matrix. This ensures that microorganisms are captured as they pass through the filter matrix with the air flow.

 

Antimicrobial Properties: Some microbial gel filters may contain antimicrobial ingredients present in the gel matrix. These ingredients are designed to prevent or reduce microbial growth on the filter.

 

Uses: Microbial gel air filters are commonly used in hospital environments, laboratories, food processing facilities, and other sterile or hygienic environments. These filters help improve indoor air quality by removing airborne microorganisms and reduce the risk of contamination.

 

Microbial Gel Filter Structure

 

 

Writer

Müştak ÇALĞAN