Effective measures to prolong the service life of filter bag for bag house dust collector
Filter bags are the key parts of dust collector bag house system. The performance of dust collector is good or bad mainly depends on selection of filter bags materials. In the total cost of manufacturing of dust collector bag house system, the proportion of filter bags cost is not small. The filter bag is a consumable product in the structure of the dust collector equipment, therefore, how long is the service life of filter bags, how to prolong filter bags’ using life, this affects the cost of equipment maintenance and the manufacture of dust collector directly.
SIIC team from INDRO filtration group introduces you several methods of how to prolong filter bags service life as followings:
1. Life analysis of filter bag
The replacement of the same type of filter bag must be after the deadline for the use of the filter. Generally speaking, the performance of baghouse filter bags can be guaranteed by the manufacturer in the service life. That is to say, during the period of use, the use of filter bags can meet users' requirements. The life span of filter bags is usually two to four years under normal conditions. According to the actual usage, the life span of some filter bags even exceeds the life standard. Because the cost of the user is affected by the life of the filter bag, the using time of the filter bag directly increases the cost of the user. Therefore, we can take some measures to ensure or prolong the life of the filter bag.
2. The reason for the filter bags damages
Among the reasons of filter bags damages, the most typical one is that the dust on the surface of the filter material is bonded together, or the dust plug and gambling caused by the exposed part temperature and the corrosive damage caused by chemical components. In case of the filter bag cages become deformed, there is the abnormal airflow smoke inside of filter bags which also can cause the filter bag damaged bag to a certain extent. The bag is damaged according to the dust emissions increase and the emergence of "chicks" effect of this type of problems the main reason is that the local surface peeling of the thin film filter, in addition there are very few because of the corrosive effects of the chemical composition and cause damage. The damage caused by the filter bag used in the initial stage is usually caused by mechanical stress. Whether the dust collector filter bags damaged for not can be judged according to its dust emission increasing and “brooding chicken effect” appear, the main reason for this problem is the partial film/lamination falling off of the filter material. In addition, some of them are damaged by chemical corrosion. The damage of filter bag used in the initial stage is usually caused by mechanical stress.
3. Analysis of effective measures for prolonging the service life of filter bag
Fiberglass filter materials are with features of high temperature resistance, withstand corrosion and good performance of anti condensation as well. In the head of sintering machine and boiler dust collector using process, compared with other media, fiberglass filter cloth has obvious performance advantages, but there are still some deficiencies in this material wear resistance and strength which will affect the service life of filter materials. Therefore, in the process of using fiberglass filter fabrics, we should pay attention to the advantages and avoid weaknesses, and give full play to its maximum effect. When the bag dust collector is designed, the following measures to prolong the life can be selected according to the actual situation.
(3-1)The proper matching of the diameter of the cages and filter bags
In general, the outer diameter of the baghouse cages is generally less than inner diameter the filter bag by 5mm. For example, filter bag with diameter 140mm, outside diameter of the filter cages is designed with 135mm, but in the use of glass fiber filter, the difference between cage outer diameter and filter bag inside diameter should be reduced to 2 ~ 3mm, during installation, it is not very easy to place, but can feel the existence of friction resistance. There is no shrinkage anymore for fiberglass under environment under 289 DEG C, so the size of the fiberglass filter bag has good stability, but the external bag house cage will produce some expansion under high temperature. During normal working time, the baghouse filter bag and bag cage can be closely adhered together. When cleaning dust and dust, the main cause is vibration and vibration to clean up dust and dust. This will not cause unnecessary collision between filter bags and steel wire bags, and minimize friction as far as possible. When clean dust, it is mainly using vibration shaking to do dust cleaning works. This will not cause an unnecessary collision between the filter bag and the bag cage wire, and minimized the friction to the maximum.
(3-2)The maximum reduction of the distance between the vertical longitudinal wires and the spacing of the fixed ring in the bag cage
In order to avoid friction between filter bag and bag cage, the number of the longitudinal wires of the bag cage can be increased. According to different filter materials, the longitudinal spacing of wires of filter bag cages are as follows:
For ptfe laminated fiberglass cloth, the spacing of longitudinal wires of filter bag cages is 20mm; for fiberglass felt, and the spacing between longitudinal ribs of filter bag cages is 25mm. The distance between the fixed rings can be designed as 180mm. If the fixed ring is designed for multilateralism, the spacing can be reduced accordingly.
(3-3)The process and process of bag cage and filter bag should be strictly controlled
In the design, we must process the strict requirements of the filter bag, bag cage welding must be more welding point at the same time by automatic welding equipment, so that the flatness of the bag cage and the vertical of the end face are guaranteed, the filter material will not be damaged by the spot burrs that exist after the welding.
(3-4)The configuration of the injection system should be scientific and reasonable
For longer dust collector filter bags, a drainage device should be designed for air injection, so that the high pressure airflow can be aligned to the middle of the dust filter bag, rather than the impact on the filter bag resulting in damage. In addition, the size of the different positions of the blowpipe should also be adjusted according to the distance of the drum.
(3-5) Long time operation of strict filter material in over temperature environment
There is a certain requirement for the working temperature of the filter material. The long time in the super temperature environment will have a great impact on the service life of the filter bag. Therefore, appropriate measures should be taken to control the inlet temperature of the dust collector.