For oil fume purification, there are mechanical separation, catalyst combustion, activated carbon adsorption, fabric filtration, wet treatment and electrostatic treatment in the market at present.

1. Mechanical separation method

The oil fume is separated by inertial collision principle or cyclone separation principle.

Disadvantages: the baffle screen is easy to break, and it is directly discharged after being discarded; Need regular maintenance and maintenance; The vertical angle of installation should be less than 1.5; The purification efficiency is not high, and it is only suitable for pretreatment or occasions with low purification efficiency requirements.

2. Catalyst combustion method

The principle of combustion purification method is to use the heat generated by high-temperature combustion to carry out oxidation reaction, so as to convert the pollutants in the oil fume exhaust gas into substances such as CO2 and H2O, so as to achieve the purpose of purification. In the combustion process, the oil fume exhaust gas passes through a self-purification catalyst, and the catalytic reaction of the catalyst is beneficial to the transformation of pollutants. Generally, ceramic or metal honeycomb is used as carrier for oxidation catalysis. This kind of fume purification equipment is only suitable for occasions with low fume concentration, such as raw food or making semi-finished products.

disadvantages: the development of catalytic combustion purification equipment is not very mature.

3. Activated carbon adsorption method

Granular activated carbon or activated carbon fiber felt is used to adsorb pollutant particles in oil fume. The characteristics of this equipment are similar to those of filtration and purification equipment, but the effect of removing odor molecules from lampblack is better.

main disadvantage: the cost of activated carbon is high.

4. Fabric filtration method

First, the fume exhaust gas passes through a certain number of metal grids, and the large particle pollutants are intercepted; Then, after passing through filter materials such as fiber mats, the particles are removed due to diffusion and interception. The commonly used filter material is polymer composite material with high oil absorption performance. This kind of equipment has the advantages of low investment, low operating cost, no secondary pollution and convenient maintenance and management. However, it has the disadvantages of large resistance, large land occupation and frequent replacement of filter media. The purification efficiency is generally 81~92%.

Disadvantages: Due to the great resistance of filter material, for example, the pressure drop of the purifier with glass fiber filter material can reach 1511Pa, and the filter material needs to be replaced frequently, so the application of filtration purification equipment is limited.

5. Wet treatment method

Water or other detergents are used to form a water film by spraying with a nozzle, and water mist is used to absorb oil fume. The oil fume particles come into contact with the water mist and water film sprayed by the nozzle, and flow down with the water droplets through the mutual inertial collision, retention, diffusion and mutual cohesion of fine particles, so that the oil fume ions are separated from the airflow. This equipment has the advantages of simple structure, less investment, small floor space, low operating cost and convenient maintenance and management.

Disadvantages: large resistance, low purification rate of submicron particles, and secondary pollution of oily sewage.

v? l? The purification efficiency of mechanical separation and purification equipment is not high, and it is only suitable for pretreatment or occasions with low purification efficiency requirements;

l? The purification rate of sub-micron particles by wet washing and purification equipment is very low, and the generated washing liquid needs to be treated;

l? The filtration and purification equipment needs to purify and replace the filter material, which consumes a lot of energy; The cost of activated carbon adsorption purification equipment is too high;

l? The development of catalytic combustion purification equipment is not very mature;

l? Electrostatic purification efficiency equipment has shown its advantages more and more because of its high purification efficiency, low pressure drop, stable operation and convenient maintenance and management. At present, its market share is close to 91%.

electrostatic oil fume purifier can be divided into traditional type and innovative type from the technical principle. Traditional equipment basically applies the principle, structure, high-voltage power supply and even appearance of traditional industrial electrostatic fume purification equipment. Its advantages are stable and reliable equipment and mature technology, but its disadvantages are heavy equipment, difficult maintenance and poor adaptability of high-voltage power supply to municipal power grid. According to the characteristics of oil fume, innovative equipment has been selected to a great extent on the basis of traditional technology, and many of its key technologies are unique to oil fume purification, and even have products that completely subvert the structure of traditional electrostatic dust removal equipment. Innovative oil fume purification equipment overcomes the shortcomings of the traditional model to a certain extent, but its advantages need to be continuously improved in the process of use.