Table of Contents
What are the design criteria for bag filter?
When designing a dust collector using bag filters, the following design sizing criteria must be studied : air to cloth ratio (filtration velocity), intersticial velocity and can velocity.
How do you estimate a filter cloth?
Simply put, the air-to-cloth ratio of a filter is the amount of air flowing through each square foot of filter media each minute. To calculate the air-to-cloth ratio for your dust collector, divide the airflow in cubic feet per minute by the total square footage of the filter media in all of the cartridges.
How do you calculate the area of a bag?
If you know the diameter of the bag, multiply this diameter by 3.14 to get the circumference. (Think back to high school math and the circumference of a circle.) Therefore, the circumference of the bags (diameter of the bag x 3.14) multiplied by the length of the bag will give you an approximate bag surface area.
How do you calculate pressure drop in a bag filter?
- The value obtained in Step 3, ∆PB is the clean pressure drop caused by the filter bag.
- SUMMARY.
- System pressure drop = ∆PS = ∆PH + ∆ PB.
- For new applications, ∆ PS should be 2.0 PSI or less.
- value should be as low as possible.
- will hold.
- us for specific recommendations when the clean ∆PS exceeds 20 PSI.
How do you calculate bag filter area?
First calculate the total cloth area of your collector by calculating the total filter area of each filter (bag diameter x 3.14 x length ÷ 144 [for number of inches in a square foot] = filter cloth area) and then multiply that figure by the total number of bags in the collector.
What is air to cloth ratio in bag filters?
Air-to-cloth ratio (or filter velocity) is simply the amount of air going through each square foot of filter media each minute. It is calculated by dividing the amount of airflow (CFM) by the amount of filter media in the dust collector.
Can velocity of bag filters?
Can velocity is the airstream velocity in the passage areas between the installed bag filters. The detached dust cake from the bag filter surface by the filter cleaning system should fall out on account of gravity.
How is bag size measured?
To measure these bags, we measure Length, by Width, by Height. For this example, we have an 8” x 5“ x10” Bag. The first measurement is the length, the second is the width, and the third is the height. Keep in mind that the handles are not included in the height.
How do you calculate CFM for dust collection?
For a rectangular port, calculate the area (multiply length times width, in inches). Then, multiply that area times 28 to find the approximate flow in CFM @ 4,000 feet per minute (FPM).
What is the function of bag filter?
The Bag Filter is a dust control device whose purpose is removing the dust contained in the exhaust gases from industrial process. It is applied to the various applications with different temperature and type of gasses by selecting the filter media accordingly.
How do you calculate CFM for air filter?
CFM = Length x Width x Height x (Air Changes per Hour) / 60 min. Calculating the CFM is measuring the air volume velocity and it is a relatively simple calculation. You need to know the length, width and height (measured in feet) of the given space as well as how many air changes per hour are required.
What is air-to-cloth ratio in bag filters?
What is the depth of a bag?
The DEPTH is measured across the gusset (side or bottom) of the bag when the gusset is EXTENDED.
What is OS size bag?
On our site, “one size” or “OS” is usually used when an item only comes in one size. Occasionally something will come in a “one size” or a “plus size,” but most likely if something comes it multiple sizes, they’ll be clearly denoted as small, medium, large, etc, as determined by the brand that produces them.
What is bag filter in HVAC?
Bag filters, or pocket filters, are used in HVAC applications as final filters in industrial, commercial and residential applications and as prefilters in HEPA installations.
How effective are bag filters?
Bag filtration is an effective water filtering option, as it can capture particulates and sediment at sizes of . 5 to 200 microns. The bags create a firm seal so that no contaminants can get out—in other words, all water must pass through the bag and undergo filtration, ensuring the safety and cleanliness of the water.
How do you calculate air filter area?
- Calculate the square feet of filter area needed for the HVAC system using the following formula: Required equipment airflow (cfm) ÷ filter velocity = square feet of filter needed.
- Calculate the size of the filter/filters in square feet using the following formula: Length x width ÷ 144 = square feet of each filter.
How do you calculate the cloth area of a filter bag?
Most companies that design baghouses know the general cloth area of their filter bags. A filter bag calculation can also be made because filter bags are round. If you know the diameter of the bag, multiply this diameter by 3.14 to get the circumference.
Why is it important to calculate the right bag filter?
The correct bag filter calculation extends the life span of your filters and keeps them working efficiently. Not having enough cloth for the air in your system results in low filter life and damaged or overloaded filters. Different materials will require different air-to-cloth ratios.
How to design a dust collector using bag filters?
When designing a dust collector using bag filters, the following design sizing criteria must be studied : air to cloth ratio (filtration velocity), intersticial velocity and can velocity.
What sizes do the filter bags come in?
These will fit just about any filter housings. Each diameter is available in two sizes, with ~16″ and 32″ being the standards for length. The smaller bags (sizes 3 and 4) are available in shorter lengths of 8″ or 14″. These small bags are useful in applications that do not require high flow.