“What size dust collector do I need?” is likely one of the first questions asked when researching dust collectors for your facility. It’s an important one. Dust collectors are a class of air pollution control devices found in industrial or commercial environments that are designed to meet EPA and workplace air quality safety requirements. They come in many shapes, sizes, and designs. Choosing the right size is essential, as much for its added production value as it is for ensuring regulatory compliance. Though the size of the dust collector will be determined by a number of factors, ultimately, the right-sized dust collector for any facility is the one that produces the needed results.
The right-sized collection system really does matter. Selecting a dust collector that is too large for a plant or facility is an obvious waste of resources—from its initial investment cost and space required for installation to the ongoing costs of energy it consumes. On the other hand, too small of a unit may save money upfront on the initial investment, but an improperly sized dust collector leads to costly inefficiencies. A smaller, undersized unit will not contain the dust and particulate matter being generated by the plant, which can lead to health issues for anyone and everyone entering the facility. Dust accumulation will also affect the effectiveness of factory equipment and machinery, leading to increased maintenance costs and lowering production rates.
Identifying Your Dust Collector Needs
The type of dust, particulate matter, and gases being generated within the facility will play a significant role in determining what kind of dust collector system works best for your facility and its size. More than likely you will be choosing from among four of the more common types of dust collectors—baghouse dust collectors such as the pulse jet or shaker systems, a cartridge dust collector, and a cyclone dust collector—depending on the industrial environment. Baghouse and cartridge-style designs are effective fabric filtration systems. The cyclone dust collector systems are used in combination with the pulse, shaker, and cartridge systems as a pre-cleaning unit.
The properties of the dust and particulate matter generated by your facility will also influence the type of collector and its size. Certain types of dust require a baghouse collector, whereas other kinds of dust require a cartridge dust collector. Cartridge dust collectors are generally applied for fine, powdery dusts and gases with efficiencies of 3 microns, whereas baghouse systems are more effective in collecting larger, sticky, or oily resin-like particulate matter with efficiencies to approximately 5 microns. The service life of cartridge filters is less than the baghouse fabric bags. Baghouse filters are also better-suited for more demanding applications with heavier dust particles.
Choosing the Right-Sized System
The size of the facility and the type of dust, gases, and particulates generated will play a big part in the selection process. Once those dust collector needs have been identified, three primary factors will determine the correct size of the dust collector. Your engineer or team of engineers will need to calculate air volume, air-to-cloth ratio, and interstitial velocity required to meet the filtration needs of the facility.
Air volume is the amount of air that passes through a dust collector when cleaning. It is measured in cubic feet per minute (CFM). That number is dependent on the properties of the dust and its characteristics. The volume of air flowing through the filter bag or cartridge needs to be accurately measured to ensure adequate ventilation. Inadequate ventilation can lead to an unhealthy work environment, machine and equipment downtime for maintenance, and problematic compliance issues.
The air-to-cloth ratio refers to the volume of air (CFM) that passes through one square foot of the filter media’s surface area. The properties of the dust being filtered will likely have a recommended air-to-cloth ratio to properly filter the dust. For maximum efficiency and filter life, the air-to-cloth ratio should be calculated to the specific application conditions.
The interstitial velocity of the air movement through the system also needs to be calculated to determine the right-sized collector. Interstitial velocity measures the upward movement of air through the space between the filter bags or cartridges and the dust collector. If the velocity is too high, the dust will be re-entrained back into the bag or cartridge causing incomplete cleaning, shortened bag or cartridge life, high-pressure drops in the system, and the waste in cost and excess, associated with the application of compressed air.
Contact the Experts at CPE Filters
Selecting the right-sized dust collector for your facility is essential for a clean, safe working environment, for keeping maintenance costs down, improving production, and remaining compliant with local and national emissions regulations. Calculating the CFM, air-to-cloth ratio and interstitial velocity will ensure that the right-sized dust collector performs as required with the facility’s air quality at an optimum level.
For more information on determining the right-sized dust collector for your facility, contact the design engineers at CPE Filters for a consultation.