Design points and solutions of catering oil fume purification project

Design points and solutions of catering oil fume purification project

Nowadays, the urban area is densely populated. While various types of catering companies have enriched our lives, they have also brought about the general problem of oil fume pollution. The oil fume is more irritating. The oil fume contains liquid and solid particles. Most of them are below 10 microns, which can generate a variety of chemicals when heated at high temperatures, which will greatly affect people and their surroundings. The resulting complaints are also constant, affecting other people and causing related punishments by environmental protection departments. For the operator, it is worth the money. The investment of a catering company and the competition in the market are quite large. In addition, there are many harmful substances in the oil fume, such as benzenes and hydrocarbons. Among them, benzopyrene is a known carcinogen. Things, (quoting the influence of soot in real life)

I have come across such a business case. The previous hotel near Baogang Avenue in Haizhu District, and a large and medium-sized catering company on Binjiang East Road all invested considerable funds in the project due to environmental fume problems.

The fumes purifier in the catering industry is mainly used for the purification of kitchen fumes. It is used in hotels, guesthouses, canteens, restaurants, restaurants, schools, factories and other places. There are five types of fumes purifiers according to different working principles.

First, the mechanical type: common mechanical types are centrifugal (cyclone dust removal), filter type, partition type and so on. Mechanical and mechanical processing technology is mainly used in large-scale industrial dust removal, which is the more mainstream treatment method in industrial dust removal.

Working principle of mechanical filter oil fume purifier:

Oil fume is introduced through the air inlet. First, large particles of oil droplets and some impurities collide with the fire prevention net due to inertia.

It is adsorbed and filtered by collision, which greatly reduces the concentration of oil particles after flowing out of the pretreatment section. At the same time, the pretreatment section has the characteristics of automatic draining oil without clogging, and impurities can be trapped in the pretreatment section. The products visited are early products. , Purification efficiency is low.

2. Wet type: The wet type mainly uses the spray (water curtain) method to filter the oil mist in the flue gas.

The high-pressure sprayed water mist droplets constantly collide with soot, and the soot is adsorbed by the water droplets to achieve the purpose of purifying the soot. This product has a better effect on large particles of oil fume, but it has no obvious effect on thinner fume. It can be used as a pretreatment for oil fume purification, and while using washing water, add surfactants, emulsifiers, etc. to improve oil-water mixing performance. However, there are certain requirements on the site, and the problem of wind resistance and leakage of pipe water must be considered during installation.

Three, electrostatic (plasma):

The electrostatic oil fume purifier uses the electrons emitted by the cathode in a high-voltage electric field, and the negative ions generated by the electrons colliding with air molecules to capture the oil fume particles and make them charged, and then uses the effect of the electric field to make the charged oil fume particles be captured by the anode. Adsorption to achieve the purpose of removing soot. According to the shape of the electric field electrode plate in the electrostatic oil fume purification equipment, the electrostatic type is further divided into a honeycomb type and a plate line type. This method has high purification efficiency and can meet the environmental protection requirements of high-demand places. The honeycomb type is better than the plate line type. However, in practical applications, the stability and reliability of the electric field are affected by frequent changes in gas temperature and humidity. The oil fume condensate on the chip has a high viscosity, which easily causes the electrode plate to lose its purification function. If an arc occurs, it will even cause a fire. The occurrence of these must be paid attention to. Therefore, it is necessary to choose high-performance high-voltage power supplies and high-quality equipment in the selection of equipment, such as Kelan and Haoke.

Fourth, photocatalysis: the ultraviolet light emitted by a special wavelength ultraviolet lamp is used to irradiate the oil fume molecules to achieve a purification method that decomposes the oil fume molecules.

Photolytic oxidation oil fume purification technology uses ultraviolet-C-band light to change the molecular chain of the oil.

At the same time, this ultraviolet rays react with oxygen in the air to produce ozone. Ozone will coldly burn oil molecules to generate water and ozone, and the odor in the flue will be eliminated at the same time. However, the effect of treating oil fume alone is not good. In practical applications, the concentration of ozone needs to be controlled to avoid causing secondary pollution.

V. Compound type: The compound type is mainly combined with wet type or activated carbon by electrostatic fume purification equipment.

At present, the more widely used is that the combined application of various methods, based on the advantages and disadvantages of a single technology, complement each other and strengthen each other, and the effect in the installation application is relatively ideal.

Sixth, the biological oil removal technology mainly uses oleophilic bacteria to biodegrade the particles of oil mist to achieve the purpose of purification. This technology has a high purification rate but also has a large area and high cost. Application in industry.

Engineering installation points

In addition to the key factors of the fume emission standard in the catering industry, in addition to the other factors we need to consider in terms of project governance are fume purification, fan matching, noise treatment, flue installation, and other surrounding factors, we must avoid construction. At the same time, it causes another secondary pollution source.

At the same time as the current survey site, the order is

1. Construction scale, floor area of ​​catering industry, what type of industry cuisine

2. The project's building structure, floor structure type, floor height, nearby residents, whether there are sensitive points such as schools, hospitals, and other densely populated places, the linear distance should be measured to predict the possibility of future impact. In addition, do you have the basic conditions for installing various types of facilities? Because many equipments are relatively large and the catering industry has a relatively high rent ratio, it is impossible to have a lot of space and places to implement the original design. This is for our engineers. The importance of the survey site is self-evident.

3. When designing the project, in addition to the purification efficiency, there is also the exhaust air volume of the project, because if it is handled well and meets the standard, but the smoke cannot be discharged, it is tantamount to say that the current methods for calculating the exhaust air volume are mostly used. The calculation of the benchmark stove and the projection area of ​​the hood, a good exhaust air is able to collect and discharge the soot vapour in the kitchen, burn the exhaust gas and the excess heat generated by some equipment, such as high-heat equipment such as steam generators, and maintain the kitchen memory In a certain negative pressure environment, if it is not enough, the corresponding positive pressure air volume should be supplemented to achieve that the entire environment is maintained in an air flow cycle.

4. The layout and calculation of the pipeline. The cross-sectional area of ​​the duct is calculated based on the exhaust air volume. There is a problem that the pressure loss, reducing diameter, tee, and elbow of the pipeline must be considered while designing the pipeline. We call it pressure loss, all kinds of purification equipment will produce pressure loss, which is the sum of pressure loss. In many rectification cases, the problem of matching the purification rate and exhaust air of the combined process of the smoke exhaust system is a realistic phenomenon that plagues many owners.

5. It is necessary to consider the exhaust fan noise and the wind noise of the pipeline, which is more intuitive to the surroundings. After all, the sound is faster than the airflow. In reality, many complaints are not caused by oil fume, but by noise, and the secondary light pollution effect. If there is a problem with oil fume, install noise reduction QI and noise reduction pipes in sensitive areas, install static pressure boxes, and fan sound insulation rooms to reduce the decibel value of the outer row.

6. Considering the problem of concentrated use in the design, it is common in ZUI, especially in large shopping malls, because the catering industry is now set up in large commercial areas, and the flow of people is good. (Maoguang Guanghua South Road Large Commercial Center), settled in large restaurants The oil fume problem was immediately caused. We should pay attention to the format issues that we will discuss with the owner at the beginning of the design, and add alternatives to the design to avoid such disputes, because many of the results are that they are not responsible for the construction and ignore the format , Resulting in a double loss of credit and value of the construction party.

7. Considering the configuration of the public flue and the installation of the fire damper, it is recommended to use a 3c certified fusible fire damper.

8. The requirements for oil fume monitoring after the discharge pipeline, the current standard reaches 3 + 1.5 = 4.5 times the diameter of the discharge pipeline

Company Case:

Oil fume treatment at Guangdong Geological Bureau, Fisherman's Wharf,

Pearl River New Town Hui Shopping Mall, 6000 square meters Fuda Shopping Mall in Huadu District, a company in Hexi, Huadu District

1. There is a unit with an emission of 60,000 and a 30-meter hood according to the projected area. However, the previous design was that two 15KW fans were installed in the kitchen, which caused emissions to offset each other. The noise was too loud. The purification design was incorrectly selected. Meet the standard, people can't stand below, let alone work properly, and the floor is very thin, only 8 cm, and it also causes low-frequency structural transmission. The leading office is less than 2 meters from the main pipeline.

2. A medium-sized chain enterprise in Tianhe, the smoke volume is too large, with an air volume of more than 40,000 in 200 square meters. It can be seen that the smoke is too large, and the leakage after the public flue is connected is serious, causing group complaints.

The above cases have been designed and processed to achieve ideal emissions and use results.