WHAT IS CLOTH RATIO?
Air to Cloth ratio is used when designing a dust collection system that employs a baghouse dust collector. In simple terms it is the total amount of fabric area (imagine all of the filter bags sown together into one big cloth) divided by the amount of air that passes through it.
To determine your Air to Cloth ratio folllow the example below, substituting your paramiters for the ones given.
Total Cloth Area ÷ Air Flow CFM ((Cubic Feet per Min) = Air to Cloth Ratio
(Bag diameter in inches x pi x bag length in inches)
Total Cloth area = 144 x total number of bags
A standard 6″ bag has a 5-7/8″ diameter
This bag is 12’ long
There are a total of 132 bags in the Baghouse
= (5-7/8″ x 3.1416 x 144″) ÷ 144 x 132
= (5.875″ x 3.1416 x 144″) ÷ 144 x 132
= (2657.79) ÷ 144 x 132
= 18.46 SF of cloth per bag x 132 bags
Total cloth area = 2,436 sq. ft.
Assume the Baghouse is handling 13,000 ACFM of air
Air to cloth ratio = ACFM ÷ total cloth area
= 13,000 ÷ 2,436
= 5.34 : 1 …Read more
Cloth ratio is the third and the most neglected parameter that must be considered in the design. It is the amount of CFM per sq. ft. of filter cloth that the fan has to move. This is a complex analysis and involves such factors as: type of cloth material, method of baghouse regeneration, physical and chemical properties of the dust, application of the system, temperature, particle size, etc.
