Dust collection equipment is responsible for capturing and filtering the particles released during manufacturing processes which are hazardous to both worker and equipment health. Dust collectors draw contaminated air through a filter or separator, trapping harmful particles and releasing cleaner air into the atmosphere or back onto the work floor. Industrial dust collectors come in various types and sizes, including fabric filter baghouses and jet dust collectors, cyclone dust collectors, wet dust collectors, cartridge collectors and downdraft tables.
When it comes to dust collection and dust collectors, there are five main types of such equipment. These include inertial separators, fabric filters, wet scrubbers, electrostatic precipitators, and unit collectors. The variances among these types may determine their suitability for specific industries and applications. Below is a brief introduction to each of these pieces of equipment and how they work.
Inertial Separators: Inertial separators work by employing a combination of forces including gravitational, centrifugal, and inertial. These forces separate the dust from the gas streams that enter it. Gravity then works to move the dust into a hopper for temporary storage. Inertial separators can be broken down into types as well, and these include settling chambers, baffle chambers, and centrifugal collectors. Settling chambers and baffle chambers are often used in pre-cleaning applications and centrifugal collectors (of which there are also many types) are used in a wide variety of industrial applications from metallurgical plants to saw mills and pulp and paper plants.
Fabric Filters: Often known as baghouses, fabric filters are very efficient as well as cost effective. Dusty gases pass through fabric bags of various materials such as felted or woven cotton and glass-fiber material. Fabric filters are relied on heavily as they have collection efficiency of over 99% for very fine particles.
Wet Scrubbers: Wet scrubbers use liquid (usually water) for another method efficient dust removal. Again a gas stream containing dust comes into contact with liquid streams, which carry the dust away leaving purer gases. Types of these wet scrubbers are based on energy uses such as low-energy scrubbers up to high-energy scrubbers.
Electrostatic Precipitators: Electrostatic precipitators use (you guessed it) electrostatic forces to remove dust from gases. With these, particles become negatively charged as they pass through a field between direct-current, high-voltage discharge electrode. These particles are thus attracted to positive charged electrodes and adhere to them to later be removed continuous vibration or rapping.
Unit Collectors: Unit collectors are employed at the source where dust is created and utilize fans along with other dust collection materials like fabric. These are usually low in cost and portable and ideal for small operations or facilities with limited space.
Though these types of dust collectors work employing different materials and methods, each is about as efficient as the next, but one might work better in your space and for your operations. Contact a provider near you for more detailed information about a system that would work best for you.
The particles released during manufacturing processes are hazardous to both
worker and equipment health, quickly leading to a number of problems if
particles are not captured by dust collection equipment and filtered from
facility air. Dust collection addresses this problem by drawing contaminated
air through a filter or separator, trapping harmful particles and releasing
cleaner air into the atmosphere or back onto the work floor. Industrial dust
collectors come in various types and sizes, including fabric filter baghouses
and jet dust collectors, cyclone dust collectors, wet dust collectors,
cartridge collectors, small dust collectors, portable dust collectors,
downdraft tables and dust collecting systems complete with multiple suction
hoods and overhanging ductwork. Dust collection is a vital process for coal
handling, cement fabrication, metal fabrication, mining, chemical processing,
woodworking, pharmaceutical, recycling and agricultural industries, among many
others. Industry-specific state OSHA regulations require companies to hold
their facilities to strict standards for indoor air quality, and the EPA and
other regulatory bodies put limits on emissions of dust, smoke and fumes into
the atmosphere. Dust collectors play a major role in helping companies meet
these requirements and improve both indoor and outdoor environments by
capturing a high percentage of the particles emitted by industrial processes.
Baghouses are the most common dust collector design and are often the most cost-effective. Baghouses draw contaminated air in through ducts to a hopper-shaped baghouse containing fabric filters made of cotton, synthetics or glass-fiber. The air is pulled through the fabric bags by a vacuum-creating fan, leaving behind dust, smoke and particles; clean air exits through the fan at the outlet, while dust particles either cling to the filter or settle into an airlock at the bottom of the hopper, which is routinely emptied. As a cake of dust accumulates on the filter, it actually increases the effectiveness of the filter for trapping tiny particles. After a point, however, the filter cake can become too thick and begins to stress the system, so occasional cleaning is necessary to ensure sufficient airflow through the filters. For this reason, baghouse dust collectors are sometimes equipped with vibrators that shake filters free of dust. Similarly, jet dust collectors are baghouses which use jets of compressed air to blow the dust-caked fabric bag filters free of excess dirt.
Some dust collectors, such as cyclone dust collectors, settling chambers and baffle chambers, do not rely on filters but instead rely primarily on gravity and inertia, and thus are known as inertial separators. Cyclone dust collectors use centrifugal, or cyclonic, air movement within a hopper-shaped chamber to separate particles from the air; the particles, being heavier than air molecules, are thrown against the outer wall of the hopper and fall to the bottom, where they are collected. Multi-cyclone dust collectors have a single main inlet on one side and a single outlet on the other side, but incorporate many cyclone cylinders inside the chamber that run concurrently; single-cyclone dust collectors have only one cyclone. Settling chambers reduce the speed of an air stream, which allows the heavier particles to settle out more quickly. Baffle chambers set up a barrier that forces the air to change directions suddenly, so that the inertia of the heavier particles does not allow them to remain suspended in the air stream and they fall to the bottom of the chamber. Cyclone dust collectors, settling chambers and baffle chambers are most effective at removing the coarser dust particles from contaminated air, and so are well suited as pre-cleaners for baghouses and other dust collectors that are more efficient at removing fine particulate.
Large facilities usually incorporate baghouses, jet dust collectors and inertial separators into sizeable dust collecting systems, with overhead ductwork and capture arms with suction hoods that hang over the workspaces where dust is formed. In such applications, the dust collector apparatus is often located outside of the facility, connected to the interior by ducts. Facilities may also use smaller, self-contained ‘unit' dust collectors or portable dust collectors, either in addition to or in place of larger systems. Generally using fabric filters or cyclonic motion to collect particles, portable dust collectors can be easily moved from place to place to provide localized dust collection. Similarly, downdraft tables are work tables with built-in dust collection equipment for filtering the dust from processes performed over the table, such as welding and wood sawing. Some special downdraft tables and unit dust collectors, known as wet scrubbers or wet dust collectors, use liquids (usually water) to intercept dust particles from the stream of gas. Others, known as electrostatic precipitators, give particles a negative charge and then attract them out of the air stream by means of a positively charged electrode. Wet scrubber and electrostatic precipitator technology is also employed in some air pollution control equipment, performing similar functions on molecular levels by removing soot, smog and fine chemical pollution from the air of industrial facilities. As the dust collecting industry advances, smaller, cleaner and more efficient separating and filtering equipment is being developed to better meet the needs of industry while increasing worker safety and protecting environmental health.
Woodworking Dust Collection System - A.C.T. Dust Collectors
Bag House Dust Collector - Quality Air Management
Small Dust Collector - Quality Air Management
Downdraft table - Bisco Enterprise, Inc.
Downdraft table - Bisco Enterprise, Inc.
Dust Collector for Surface Preparation Applications - A.C.T. Dust Collectors
Dust Collector Terms- The amount of process gas or air entering the fabric collector (baghouse) divided by the square feet of cloth in the fabric collector.
- Form of pneumoconiosis caused by the inhalation of asbestos minerals into the lung, resulting in lung scarring, breathing problems and various forms of cancer.
- Also called "leakthrough," it is the ability of particles of dust or fumes to migrate through the fabric bag.
- Also referred to as "filter cake," it is the dust buildup occurring on the surface of the filter medium during filtration that often aids in the filtration process.
- International professional designation available through training and testing by the Association of Energy Engineers (AEE).
- Family of chemicals used as refrigerants, being tightly regulated and phased out of production due to stratospheric ozone depletion potential. Examples: R-11, R-12, R-113, R-114, R-115.
- The act of dipping the filter medium into a solution in order to lubricate the fibers to reduce self-abrasion.
- Electrodes in an electrostatic precipitator that attract and collect negatively charged particles of dust.
- The amount of dust that the gas or air contains. Concentration is expressed in grains per cubic foot or pounds per hour.
- Electrodes in an electrostatic precipitator that negatively charge dust particles.
- Conductors or parts of a semiconductor that create an electrical connection with nonmetals or control the movement of electrons.
- Filter in a fabric collector consisting of woven or felt material such as cotton.
- Toxic particles that penetrate the lungs, causing lung dysfunction and scar tissue formation.
- The porous barrier used in the filtration process to separate the particles from the fluid stream.
- The fabric collector equipment from inlet flange to outlet flange.
- Cloth wear in a fabric bag caused by excessive bending.
- A hood-shaped inlet designed to collect contaminated air and direct it into the exhaust dust system of a baghouse.
- In dust collecting systems, the area in which the collected dust is stored.
- Also called "nuisance dust," it consists of particles of which quartz and other silicates compose less than one percent.
- Medium- to large-sized dust particles that do not reach the lower respiratory tract but remain in the upper respiratory system, nose and throat.
- A device that sucks up fine particles from fluids like oils and even dry smoke using a three-phase motor. The inner drum rotates and draws the mist particles to the center of the drum where they are forced together and eventually pass through perforations in the drum and back into the machine's coolant tank, while clean air blows past the motor and back into the outside environment.
- Centrifugal separators containing several parallel cyclones that separate dust particles according to texture.
- Common high-voltage electrostatic precipitator consisting of flat collection plates along which discharge electrodes lie.
- Respiratory ailment caused by excessive inhalation of metallic or mineral dust matter. Pneumoconiosis also includes diseases such as silicosis and asbestosis.
- Part of electrostatic precipitator that transfers dust from the collection plates to the hopper.
- Small dust particles inhaled into the lower regions of the lungs that are responsible for different types of pneumoconiosis.
- Incurable, potentially deadly type of pneumoconiosis caused by the inhalation of silica dust particles, resulting in lung diseases such as emphysema. Silicosis progresses even after contact with silicates has ceased.
- More or less consistent wear on the dirty side of the fabric bag cloth.
- Consists of all dust particles, whether respirable or inhalable.
- High-voltage electrostatic precipitators consisting of cylindrical collection plates that rotate around the discharge electrodes.
- Part of an electrostatic precipitator that transfers dust from the collection plates to the hopper.