Fabric filters pressure drop

The filter ratio for baghouses, also called the gas to cloth ratio, varies from 0.6 to 1.5 m of gas per minute per square meter of fabric. The pressure drop across the fabric is a function of the filter ratio it ranges from about... 

Pressure drop— Another factor of major importance in a fabric filter is the pressure drop caused by the combined resistances of the fabric and the accumulated dust layer that builds up on the surface of the fabric. The pressure drop for an operating fabric filter with dust cake accumulated on the fabric can be estimated using the following equation [2,18,41] ... 

Gas Pressure Drops The filtration, or superficial face, velocities used in fabric filters are generally in the range of 0.3 to 3 iTi/min (1 to 10 ft/min), depending on the types of fabric, fabric supports, and... 

Cyclone precleaners are sometimes used to reduce the dust load on the filter or to remove large hot cinders or other materials that might damage the bags. However, reducing the dust load on the filter by this means may not reduce the pressure drop, since the increase in Ko produced by the reduc tion in average particle size may compensate for the decrease in the fabric dust loading. 

Preconditioning for Particulates Heavy particulate loading of the inlet gas with dust, grease, oils, or other aerosols can be very dam-aging to the pore structure of the filter bed, resulting in an eventual pressure-drop increase. Oils and heavy metals that are deposited on the filter bed can be poisonous to the microorganisms that live within the biofilm. Particulate APC equipment such as fabric filters and venturi scrubbers are generally adequate for this level of particulate removal. 

Practical application of fabric filters requires the use of a large fabric area in order to avoid an unacceptable pressure drop across the fabric. Baghouse size for a... 

Air cleaning (dust collection) can be cost effective for LVHV systems handling valuable dusts. Care must be taken when handling potentially toxic dusts from air cleaners. Regular, routine reconditioning of fabric filters (e.g., by automatic shaking or pneumatic pulsing) is impottant. This can be accomplished on a set maintenance schedule or as a function of pressure drop across the fabric filter. It is not recommended to recirculate airflow back to the workplace because of the low air volume and potential hazards in the event of filter failures. 

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