Filtration mechanism:
Liquid flows from the filter bag to the outside of the bag, and the filtered particles are trapped in the bag, so that the working principle of the bag filter is pressure filtration. The complete bag filter system includes three parts: filter container, support net basket and filter bag.
The liquid to be filtered is injected from the top of the filter bag supported by the support basket, which makes the liquid evenly distributed on the filter surface, so that the flow distribution throughout the medium is a uniform surface, without the negative effects of turbulence.
Liquid flows from the filter bag to the outside of the bag, and the filtered particles are trapped in the bag, so that when the filter bag is replaced, the filtered liquid will not be contaminated. The handle design in the filter bag makes the filter bag faster and more convenient.
Features are as follows:
High circulation capacity.
Long filter bag life.
The uniform flowing liquid makes the particulate impurities evenly distributed in the filter layer of the filter bag.
Higher filtration efficiency and lowest cost.
- Selection of filter material
First of all, according to the chemical name of the fluid to be filtered, find the available filter material according to the chemical combination taboo, and then for its operating temperature, operating pressure, pH value, operating conditions (such as whether it needs to withstand steam, hot water or chemical sterilization Etc.), evaluate one by one, and remove the unsuitable filter materials. Use is also an important consideration. For example, the filter material used for medicines, foods or cosmetics must be approved by the FDA; ultra-pure water must be selected pure and does not contain released substances that will affect the specific impedance; filtered gas is required Choose hydrophobic materials and whether “hygienic filtration” design is needed.
- Filtration precision
This is a most troublesome question. For example, to remove particles visible to the naked eye, use a 25-micron filter; to remove clouds in the liquid, use a 1 or 5 micron filter; to filter out the smallest bacteria, a 0.2-micron filter is required. The problem is that there are two types of filtering accuracy units: absolute accuracy / nominal accuracy.
- Absolute accuracy / nominal accuracy
Absolute accuracy refers to 100% filtering of particles with the indicated accuracy. For any kind of filter, this is almost an impossible and unrealistic criterion, because 100% is an infinite value. Absolute filters commonly known on the market such as membranes, etc., strictly speaking, can only be called “approaching absolute” filters, while others belong to nominal accuracy. This is the main problem: “Nominal accuracy does not have a standard jointly recognized and followed by the industry.” For this problem, experienced professional filter suppliers will help to choose the filtration accuracy, and the fundamental solution is “trial”.
- Design of filtration system
The design of the filtration system involves a wide range. For example, which pressure source should be selected and how much pressure is required; whether two sets of filters need to be installed in parallel to suit the system for continuous operation; Coarse filtration and fine filtration; whether it is necessary to install check valves or other devices in the system, etc. These all require the user to work closely with the filter supplier to find the most appropriate design.
- How to use the filter bag
Filter closed filtration: The filter bag is used together with the matching filter, using the system fluid pressure to squeeze the liquid through the filter bag to achieve the purpose of filtration. It has the advantages of fast flow rate, large processing capacity and long service life of the filter bag. It is especially suitable for the occasion where large flow requires closed filtration.
Self-flowing open filtration: The filter bag is directly connected to the pipeline through a suitable joint, and it must be filtered by the gravity pressure difference of the fluid. Its remarkable feature is that it does not require equipment investment, and the filtration is simple and feasible. It is especially suitable for economic liquid filtration with small specifications, multiple varieties, and intermittent type.