Selecting the Right Filter Bag

When selecting the filter bag, we need to take the following basics into consideration:

First, we need to consider the general application of the filtration. For example, the filter media applied for pharmaceuticals, food or cosmetics must be approved by the FDA. For EDI water filtering, we must select the ultra clean filter bag which is lint-free. For gas filtering, we must select the hydrophobic filter bag.

Next, we should understand the filtration mechanism of the bag filter system: the liquid flows from the inside of the filter bag to the outside of the bag, and the filtered particles are trapped. In the bag, bag filtration works by pressure filtration. Thus, we might as well consider the operating temperature, operating pressure, pH, operating conditions when we look into the material of filter bag we’ll use.

At the same time, we may refer to the chemical name of the fluid to be filtered and its taboo to rule out the material that shouldn’t be used as the filter bag for filtering such fluid then we turn to the right type of material. Manufacturers usually use PE, PP, PTFE, or NMO material for making filter bags.

Last, let’s make a wise choice out of various microns and sizes! The nominal accuracy does not have a standard that the industry has jointly identified and complied with. That is to say, A can set the nominal accuracy in 85-95%, while B is better at 50-70%. In other words, A’s 25-micron filtering accuracy may be equal to B’s 5 microns or finer.

For this problem, we HAWACH as the experienced filter supplier could help out. According to the viscosity and temperature of the filtration, we can calculate the size of the filter that’s needed, how many filter bags need to be installed and advise comprehensively per the generalized information.