What types of air filters are divided into - What types should be used in the painting project

After the above, we should have a certain understanding of how to select air filters in the painting workshop, and the primary classification of air filters in the painting workshop, in order to help you have a more profound understanding of various types of air filters.

Abstract: This paper discusses the intention of using air filter to clean the air in painting operation, and emphatically introduces the selection, protection and equipment strategy of filter filter in ventilation system.

The advantages and disadvantages of repeated use of air filter are analyzed.

antecedent

To paint the way for the appearance of the product decoration, for people to know, but today's various products on the high quality of coating requirements is difficult to imagine. For example, in the daily use of mobile phones, personal computer cases, even small cosmetics containers, it is difficult to investigate the gray particles and concealer on the appearance of products. The exterior coating of domestic car body requires only 2 particles in the most significant part. The coating quality of the engineering plastic exterior parts of cars, including the front and rear bumpers of cars and door protection panels, is also required to reach the equal appearance. It is reported that the German Volkswagen MOSEL factory requires the exterior coating of the body to be about 4 particles. In view of such high requirements, has followed the development of painting materials, the innovation of painting equipment and the gradual improvement of construction skills, mechanization, automation of the painting production line is increasingly sophisticated and widely used, and can be met. But one of the key skills can not be said, because it can maximize the effect of ensuring the high decoration of the product surface coating, which is the skill of selecting air filter for clean treatment in the painting environment, because the gray particles suspended in the air will affect the quality of the coating, serious loss of human, material and financial resources will be formed.

1. Sources of dust and ash particles

In addition to the quality factors of the painting data, the dust and ash particles in the painting operation are suspended in the painting environment. Ash particles deposited in ventilation ducts; Ash particles adhering to the surface of the spray painting room, drying room, drying room and transfer equipment, flying on the wet paint film or other coating appearance; The dust brought by the operator and the scattering of the fabric fibers are the killer mace that affects the quality of the coating. Therefore, it is necessary to improve all the staff to establish a clean understanding of the working environment, realize that every link in the process of painting can not ignore the investigation of the influence of ash particles, and eliminate. As long as this can always maintain the high quality of the coating and production process of high power operation. How to prevent and control dust particles in painting environment is the key to painting quality.

2. Selection of air filter in ventilation system

The selection of air filters in the ventilation system of painting workshop varies with the decoration requirements of painting products. Figure 1 lists the power standards of air filters to provide planning reference.

3. Classification description of air filter

(1) Air filters can be divided into primary air filter, medium air filter, high efficiency air filter and super high efficiency air filter according to the filtration grade. The power of the primary air filter ranges from G1 to G4, and the power of the filter is measured by grey particles above 5 μm. The power of the medium effect air filter is F5 ~ F9, and the power is measured by 0.5 ~ 1 μm grey particles. The power of high efficiency air filter is H10 ~ H14, and the power is measured by 0.3 μm grey particle. The power of the ultra-high efficiency air filter is above U15, and the power is 0. 08 ~ 0. The 15 μm gray particle was the preface of the test.

(2) Air filter according to different data can be divided into metal air filter, non-woven air filter, artificial fiber air filter and glass fiber air filter. Aluminum mesh and stainless steel mesh and other metal data and non-woven fabric for the manufacture of the initial effect, that is, G1 ~ G4 power air filter data; Artificial fiber and glass fiber are used for the manufacture of medium efficiency air filter, but the filter effect of glass fiber is more ideal than that of artificial fiber under the condition of equal power. The manufacture of air filters above the high efficiency grade can only use glass fiber paper or ultrafine glass fiber data.

(3) According to the shape of the air filter can be divided into plate air filter, bag air filter and box filter.

4 Air filter selection instructions

Let's introduce the selection of air filters by taking the planning of the cleaning requirements of the painting workshop as an example:

It is necessary to plan the cleanliness of the air filter in the control workshop to reach F8 for the 10,000 level of cleanliness. The basic selection of the air filter in the whole air supply system is F5-F8-F5-G3.

(1)F5 is the cotton top air filter. The air filter is mainly placed on the top of the working workshop, and the external air flows into the workshop through the air filter. The air filter is mainly used to achieve the uniform flow effect and filter effect, so that the air can be uniformly dispersed into the workshop, in order to prevent the air flow rate from being fast and slow and affecting the painting operation. A small number of domestic manufacturers do not pay much attention to the selection of top cotton, and some choose the primary effect of non-woven fabric instead. In fact, non-woven fabric only has the effect of filtering at first, and the effect of flow is very small, so do not repair the top cotton products because of the small amount of saving.

(2)F8 is a high school air filter. The air filter is the terminal air filter set for the cleanliness requirements of the workshop, which is the cleanliness level of the air filtered to meet the requirements of the workshop.

The filtration power is 90 % ~ 95 % under colorimetric test. The air filter information is generally glass fiber and artificial fiber.

(3)F5 is a medium effect air filter. This air filter is designed to protect and extend the service life of F8 air filter, because the higher the grade of air filter replacement cost is higher, we based on the function of high power air filter and in order to reduce the cost of protective set low power air filter. The filter power is 45 % to 50 % under colorimetric test. The air filter information generally choose glass fiber and artificial fiber. Some units also choose thicker non-woven fabric for this level of air filter, very undesirable, because this kind of non-woven fiber line diameter is too thick, can not reach the level of power.

(4)G3 is the primary air filter. This air filter has the same effect as F5 air filter, in order to protect and extend the service life of F8 air filter. Its filtration power is 75%-80 % under specific gravity test. It is generally made of non-woven material.

(5) In addition, the air temperature into the baking production line varies with the curing temperature, and some as high as 200 ℃, because the heating equipment may produce dust and missing dust in the pipeline, the air filter is placed on the hot air end, which requires the air filter temperature to reach 200 ~ 300 ℃. The air filter is generally F6 ~ F8 power, should be high temperature resistance requirements of the air filter data is generally glass fiber, general resin treatment products at 200 ℃, the temperature resistance of pure glass fiber can reach 450 ℃.

Of course, there are many grades of air filters. The relevant personnel can set and choose the air filter according to the requirements of their own operation in the power, shape, data and other aspects of the air filter. For the level, the general reasonable choice is taken to set 1 air filter for every 2 ~ 3 levels. Here, it is advocated that there are three points to consider in the selection of air filter:

First, the function of the final stage air filter should be reliable;

Second, the power of the protection level air filter should be reasonable;

Third, the protection of the primary air filter should be convenient.

5 Air filter protection and equipment

In order to keep outstanding clean air in the spray shop, it is necessary to check and replace the air filter and air filter frequently. The standard of general replacement depends on the prompt of the differential pressure meter to determine whether it is time to replace. The final pressure loss of the air filter used in the painting industry is generally set at about 250 Pa, and the patio screen is 450 Pa. After a period of use, the pointer on the differential pressure meter will move to the set value when the operator will be prompted to replace the filter network in the face of loss effect arrangement. There are two kinds of differential pressure scoring: automatic alarm and non-automatic alarm. The non-automatic differential pressure meter requires the operator to investigate the value on the table every day to confirm whether to replace the air filter. Of course, in the usual also need to check the air filter, once found damaged should be replaced immediately.

In addition to the understanding of pressure difference, we should also do a system of cleanliness detection on a regular basis. If we find that there is no place to meet the requirements, we should find out the reason and deal with it in time.