The Basics of an Industrial Dust Collector
Industrial environments can generate airborne particles that are hazardous to health, reduce visibility and need to be removed. Industrial dust collectors control and reduce these harmful particles in the workplace to create a clean environment for employees and production processes.
Different industries require specific extraction methods for pollutants, harmful matter and gas fumes but all are designed to filter contaminated air and discharge sanitized air back into the workplace. There are five main types of industrial dust collector:
Filtration
The filtration system is the core of an industrial dust collector. The type of filter you use depends on the size, shape and composition of the particles being handled and how abrasive they are. Knowing the material you’re handling will also affect how much air and velocity is needed to effectively suck up the dust.
Effective dust collection systems control and remove harmful contaminants, particulate matter, gas fumes, and dust from the air or gases in manufacturing environments. The systems are engineered to meet the specific extraction needs of each industry and ensure proper air purification.
Warehouses, plants and factories often have abrasive materials and coatings that break down or create dust as they are applied to products. When this happens, it can migrate through the facility and contaminate machinery, products and employees. This is why facilities need industrial dust collectors to protect workers and equipment.
Baghouse dust collectors come in various designs, and are the most commonly used systems due to their 99% efficiency. Pulse jet systems use a blast of air to “clean” the filters by pushing the accumulated dust down into collection hoppers. This prevents the buildup from affecting airflow through the system and ensures it continues working efficiently.
Blower or Fan
Industrial dust collectors are designed to filter air, fumes and mist in industrial dust collector manufacturing facilities to meet environmental and workplace safety requirements. The systems help reduce fire hazards and improve employee health, productivity and product quality.
The heart of any effective industrial dust collector system is the blower or fan. It provides mechanical energy to move the contaminated air from the source and through the ducting, filters and discharge mechanisms. Industrial fans have a variety of shapes, sizes and designs that include flat or complex spirals and airfoils to create different levels of pressure in the airflow. While common table, box and ceiling fans are great for small shop woodworking, they do not generate enough pressure or air volume to power our ducting, filters and separators.
Most types of industrial dust collectors use a combination of ambient and source air to achieve optimal results. Ambient systems typically rely on gravity to draw the fumes upward and circulate the air, while source capture systems capture the airborne contaminants at their origin.
The choice of the best type of industrial dust collector depends on the facility’s size, types of processing and contaminant types. The most popular industrial dust collection system is a baghouse design that uses different kinds of bags and filtration methods to capture the contaminated air. The system is sized to handle the specific type and size of dust particulate, has industrial dust collector a properly engineered ducting and coupled industrial blower, and a cleaning mechanism in the system to remove the collected dust from the filters.
Ductwork
The ductwork connects the dust collection system to the machine or workspace. The ducts need to be properly sized in order to maintain a constant “carrying velocity” that keeps the dirt moving through the duct. If the ducting is sized incorrectly or if there are improper elbows used, air flow can be interrupted and the dust collector will operate less efficiently.
Ducts for an industrial dust collection system can be made of either a flexible hose or hard, fixed metal. There are pros and cons to both. A flexible hose has the advantage of being lightweight, easily portable and inexpensive. However, it has the disadvantage of being more susceptible to clogs and the need for frequent cleaning. Hard, fixed metal ducting is generally fabricated of galvanized or stainless steel and may be fitted with either flanged or clamp-together ends/connections. Metal duct is favored by most as the rigid interior reduces static electricity buildup and helps to maintain pressure over long runs.
Clamp-together ducting is preferred as it offers quick and easy installation, adjustability, re-usability, efficiency (as compared to spiral duct) and the ability to accommodate changing equipment needs. Clamp-together ducting is also designed to meet SMACNA (Sheet Metal and Air Conditioning Contractors’ National Association) construction standards and can be fabricated in heavier gauges for abrasive applications.
Electrostatic Precipitator
An electrostatic precipitator, or ESP, is the main device in an industrial dust collector that uses electrical energy to charge particles positively or negatively. This causes the particles to be attracted to and collect on plates, which are then drained of particles by gravity or pumped out through a wet collection system. There are many different designs for an ESP, but the most common is a plate or stack of flat metal plates that are stacked vertically and spaced 1cm to 18cm apart. The plate or stack is surrounded by wires and has an initial negative voltage applied to the wire that creates an electric field between the wire and the first set of collection plates. This ionizes the smoke or gas stream and makes the particles more likely to be attracted to the positive plates, where they remain after the extra electrons are removed by the electric field.
There are containers called hoppers present in both dry and wet ESP systems that collect the collected particulate matter. The hoppers are shaken periodically or flushed with water to release the dust into containers for designated treatment, disposal, or recycling. Depending on the type of dust being captured, an ESP may also be used to condition the flue gas stream by a variety of means including adsorption, condensation, and modification of particle resistivity.