What is a bag filter?
A bag filter operates on the microfiltration principle. In bags, the liquid is purified by passing through small permeable pores. Large amounts of water can be filtered using bag filters. These pores range in size from 1 to 200 microns. The capacity is determined by the surface area of the bags. Larger systems can clean up to 500 m3 per hour (multi bag filters).
What are bag filters made of?
A bag filter, as the name implies, is a small bag made of a filtering material that attaches to a sturdy ring at the opening. The bag is placed inside a filter housing, and as it fills with water, it seeps through the filter's tiny holes, removing unwanted contaminants. When you need a high flow rate and basic purification, bag filtration is an excellent choice.
The liquid flows from the top of the filter house (made of stainless or epoxy coated carbon steel) and is evenly distributed among the bags. The liquid drains from the bottom, leaving the dirt behind.
All of the dirt is trapped inside the bag because it is locked at the top of the vessel. The filter vessel never needs to be cleaned after use. Bag filter systems are used in a variety of industrial solutions. Milk products, paint, lime, beer, and other treated liquids are examples.
Key Applications of bag filters
Bag filters are distinct in that their primary application is in commercial, agricultural, and industrial settings.
A bag filter is rarely, if ever, recommended for residential filtration. The ability of a bag filter to capture sediment without slowing down the flow rate makes it ideal for these industries. Water can simply flow around a large piece of sediment trapped in the bag because there is still plenty of open surface area.
This differs from filters with small openings in that if the filter surface becomes clogged with sediment, the flow of water is slowed or even stopped. Not only is it advantageous to maintain flow rate, but you can also remove the filter from its housing and manually remove the trapped material.
Another significant advantage of a bag filter is its reusability.
Selecting a Bag Filter
A bag filter system is an excellent choice for removing sediment. With so many options available, deciding which is best for you can be overwhelming.
Consider the following key questions to aid in the selection process:
Q1: What kind of sediment are you removing with the filter?
Knowing the size of the contaminant allows you to choose the best micron rating (the size of the holes in the filter) and media type (polyester, polypropylene, or nylon). Furthermore, the type of sediment you use will influence the type of filter housing you should use. Carbon steel works particularly well in petroleum-based applications, as well as with soaps and cleaning solutions.
Q2: What is the pH of the water that is being filtered?
The pH of your water is important to know because it can affect the material of your house. Aluminum housings, for example, are best used in water with a pH of 6.5 to 8.5, so if the water needs filtration and has a higher or lower pH, use a different housing material.
Q3: How much water are you using on a daily basis?
If you expect to filter a large volume of water, you'll need to choose a system that can handle it.
Q4: What is the maximum and minimum temperature of the water?
Filters perform differently at different temperatures, so choosing a filter that performs best at high temperatures will be useless if your water temperature is low.
Q5: What is the optimum flow rate?
Flow rate and micron rating are linked - a higher micron rating has a higher flow - so it's critical to balance the sediment size and desired flow rate when designing a filtering system.
For more information, contact Netsol Water.