All Categories

What is the knowledge of activated carbon chemical filter-V-type activated carbon air filter?

2022-06-09 Page view : 7 views

Function Description:

V-type activated carbon air filter is what we usually call box-type granular activated carbon filter, also called activated carbon chemical filter, which is mainly used to remove chemical gas pollutants in the air to meet the requirements of microelectronics, nuclear industry, pharmaceutical, chemical, environmental protection, laboratory animals, light industry and other industries.

 

With the development of industry and the expansion of cities, the concentration of harmful gases in the atmosphere has increased; with technological progress and improvement of life, people’s requirements for pure air have increased. The demand for chemical filters is gradually increasing. Most of the current chemical filters are activated carbon air filters. The V-type activated carbon air filter uses carbon particles with high adsorption beyond activated carbon particles as the filter material. It has a highly developed microporous structure, large adsorption capacity, fast adsorption and desorption speed, and good purification effect. For the removal of odors and higher density gas phase pollutants.

The V-type activated carbon air filter mainly adopts the W/V-shaped structure, which increases the ventilation area and thus increases the air volume.

 

It is recommended to add at least F7 filter to the front end of the activated carbon filter to protect the activated carbon filter and prolong its service life.

 

W/V-shaped structure general thickness series: 292mm.

General application of V-type activated carbon air filter:

◎Electronic components, odors in food processing plants.

◎The rancid smell and other odors of hospitals and museums.

◎The smell of kitchen and bathroom.

◎The smell of paint in the paint spray workshop.

 

With activated carbon air filter technical knowledge:

 

  • Adsorption Principle

Activated carbon selectively adsorbs gases rather than mechanically “filtering” impurities.

There are a large number of micropores on the surface of activated carbon, most of which are smaller than 500? (1? =10-10m). The total internal surface area of micropores per unit material is called “specific surface area”, and the specific surface area can be as high as 700-2300m2/g.

 

When it comes to adsorption, the harmful gas in the air is called “adsorbate”, and activated carbon is called “adsorbent”. The adsorbate sticks to the inner surface of the micropore due to intermolecular attraction. If it is accompanied by a chemical reaction, it is called chemical adsorption, otherwise it is physical adsorption.

 

When the adsorbate is adsorbed by the adsorbent, part of the adsorbate will also be released from the adsorbent, which is called “desorption”. During use, the adsorption capacity will continue to weaken, the desorption will increase, and if it increases to a certain extent, the activated carbon will be scrapped.

 

Occasionally, heating or steam fumigation can remove the adsorbate from the adsorbent and regenerate the activated carbon.

 

  • Activated Carbon Material

Activated carbon materials are divided into granular carbon and fiber carbon.

Traditional granular activated carbons include coal charcoal, wood charcoal, coconut shell charcoal, and bone charcoal. Sometimes granular carbon is powdered, bonded to other porous materials, and processed into shape.

Fiber activated carbon is made from carbon-containing organic fibers. It has small pore size (<50?), large adsorption capacity, fast adsorption and fast regeneration. Commonly used fiber substrates are phenolic, plant fibers, polyacrylonitrile, and asphalt.

 

  • Activated Carbon Adsorption Performance

Adsorption capacity – For a certain gas, the amount that can be adsorbed by a unit of activated carbon is called “adsorption capacity”. Different materials, or adsorption of different gases, have different adsorption capacities.

Residence Time ─ The time for the airflow to pass through the activated carbon layer is called “residence time”. The longer the residence time, the more sufficient the adsorption. In order to maintain sufficient residence time, the carbon layer should be thick enough and the filtering wind speed should not be too high.

 

Service life ─The new activated carbon has high adsorption efficiency, and the efficiency decreases continuously during use. When the concentration of harmful substances downstream of the filter is close to the allowable range, the filter is scrapped. The use time before scrapping is the service life, also known as “penetration time”.

 

Selectivity – Generally speaking, gases with high molecular weight or high boiling point are easily adsorbed; volatile organic gases are easier to adsorb than inorganic small molecular gases; chemical adsorption is more selective than physical adsorption. Activated carbon is chemically impregnated to increase its adsorption capacity for specific gases.

 

  • Selection of Activated Air Carbon Filter

The main factors affecting the adsorption efficiency and service life of the activated carbon filter are: the type and concentration of pollutants, the temperature, pressure, relative humidity, and residence time of the airflow.

 

In the actual selection, the type of activated carbon and the form of the filter should be determined according to the types of pollutants, the concentration and the air volume to be treated. Activated Carbon filter manufacturers can determine whether activated carbon should be replaced by monitoring changes in contaminant concentrations before and after the filter. However, there is no convenient and practical monitoring method in China at present. Therefore, the user can only determine the service life of the activated carbon filter according to the prescribed cycle or experience.

 

During use, the resistance of the activated carbon filter does not change, but the weight will increase. An experienced professional can determine the service life of the filter according to the weight change.

 

The upstream and downstream of the activated carbon filter should have a good dust filter, and its efficiency specification should not be lower than F7. The upstream filter prevents dust from clogging the activated carbon material; the downstream filter filters out the dust generated by the activated carbon itself.