Types of Industrial Dust Collectors
Dust collectors are vital equipment for many industries. Effective dust collection systems control and reduce the amount of airborne contaminants, harmful matter and gas fumes that enter a facility’s work environment and atmosphere.
They also protect products from contamination, reduce worker discomfort and sick leaves, and keep production moving smoothly.
Dust Types
When it comes to industrial dust collectors, there are many types of systems that are available on the market. These pieces of equipment are designed to purify and filter air and dust contaminant matter during industrial processes to meet workplace safety and environmental requirements.
The type of contaminant that will be collected and the overall system design will affect the effectiveness and cost of the equipment. A variety of factors influence this, such as the moisture level, texture and size of the dust to be collected; process exhaust conditions of temperature and moisture, combustible or non-combustible dusts, as well as local and state governing guidelines for the air quality at your facility.
Combustible dusts are dangerous because they can ignite and explode when exposed to oxygen and heat, such as from a spark, cigarette or hot wheel bearing. They are also a health hazard because they can build up in the lungs to cause irritation and breathing difficulties. The best option for handling combustible dusts is to use a specialized combustible dust collection system designed to handle these potentially explosive materials while maintaining adherence with ATEX and NFPA standards to ensure worker safety and avoid costly damage to the facility.
Non-combustible dusts are less hazardous because they do not react with oxygen to ignite and burn, but can still pose a health risk when inhaled. They can irritate the nose, throat and lungs and may lead to respiratory illness or even cancer when exposure is chronic. The most common non-combustible dusts that Nederman handles include metal, wood and plastics.
The degree of dust collection required will be influenced by the potential health and safety risks, the plant location, the allowable emission rate, the nature of the dust and whether or not it has salvage value. It will also be affected by the ductwork, noise reduction and other features that are needed to be integrated into the dust collection system.
Types of Dust Collectors
There are many different types of dust collectors to meet the varying needs of industrial environments. For example, they are often used in woodworking applications for the control of sawdust, shavings, and fumes. They are also used to maintain air quality in facilities that conduct carbon machining, concrete grinding, blasting, composite manufacturing, welding, pharmaceutical production and more. They are even utilized in post-flood/fire/disaster building restoration work to clear the air of ash, dust, debris and other hazardous material.
The type of industrial dust collector chosen depends on the size of the facility and the amount of dust it generates daily. It is important to understand the filtration capacity of each device as well as its ability to handle a specific range of temperature and moisture. In addition, each system is powered by electric motors of varying sizes that are selected to supply the power needed over a wide range of process conditions.
Depending on the application, other factors that impact which type of dust collector is chosen include:
The most common way to separate the particles in an industrial dust collector air stream is to use mechanical forces, such as gravitational, thermal, or kinetic energy to move them away from the gasses. This allows the contaminant to be separated from the air stream and then deposited in a container where it is temporarily stored.
Another method for separating particulate matter is to use electrical charges to attract them. Electrostatic dust collectors, for instance, use static electricity to charge soot, ash, and other debris from exhaust gases, separating them from the gasses. This process is often employed at coal-burning power plants.
Other types of industrial dust collection equipment are wet scrubbers, cyclone dust collectors, unit collectors, and inertial separators. In some cases, these devices are equipped with special systems to collect flammable and explosive materials.
The type of dust collector chosen will also depend on a plant’s regulatory compliance status. Some companies are required to obtain a permit from a local, state or federal agency that indicates the specific emission guidelines and control equipment requirements. Regardless of a company’s permitting status, a high level of air filtration is crucial to maintaining healthy and productive working environments.
Baghouse Dust Collectors
When it comes to industrial dust collectors, a baghouse system is often the best choice. It consists of anywhere from 6 to 900 felt bags that filter dirty air. Dirty air enters the system through an inlet, and, in larger units, hits a baffle plate first to knock large particulate down into a storage hopper below. The polluted air then passes through a series of baghouse filters and cages. After the filter surface is polluted with a heavy “cake” of dust and other particulate, the filters are cleaned by a pulse-jet cleaning system that uses bursts of compressed air to dislodge the cake and clean the filter surface.
The baghouse system is commonly used in a wide range of applications and industries that produce fine dust, including metal fabrication, electronics, pharmaceuticals, chemicals, food processing and woodworking. When a plant wants to meet strict environmental regulations, an effective industrial dust collection system is critical.
In addition to dust collection, the system needs to dispose of the pollutants efficiently and safely. The hopper, which can be located in many different areas of the system, is industrial dust collector where all the collected material ends up after it’s been cleaned from the filter surfaces. It’s important to empty and clean the hopper regularly so that it doesn’t overflow, which can damage or ruin the bags.
While most plants choose to have a baghouse system, it’s important to understand that there are other options, such as cartridge dust collectors. The decision on which type of collector to use depends on the degree of dust collection required and a host of other factors, including whether or not the plant is located in a sensitive area, the allowable emissions rate, the nature of the material being processed, and the salvage value of the product. Choosing the right type of collector should also consider the cost of operating and maintaining the equipment. Typically, a baghouse system is cheaper than a cartridge dust collector, but each has its pros and cons. A qualified air pollution control professional can help you determine which is the best option for your particular application.
Cyclone Dust Collectors
Unlike bags or scrubbers, cyclones separate the dust particles by centrifugal force. This is how they got their name. Dust is drawn into a cylindrical body in the center of the collector through an inlet. The resulting airflow resembles a vortex, pushing larger chips and debris towards the primary collection point at the top, while finer dust is pushed to a secondary collection point in a hopper at the bottom. These two points help eliminate heavy dust mixed with finer particles and are useful in woodworking, pulp and paper, shot blasting, steel and aluminum processing, grain and agricultural, mills, recycling plants, and other industrial settings.
Cyclone dust collectors are the simplest and least expensive of all industrial dust collection devices. They are easy to operate and require no ductwork. They are often installed as a pre-filter to eliminate the large and coarse particles that would otherwise damage baghouse filters. This reduces internal velocities and extends filter life.
In a wet cyclone, the centrifugal action of the swirling cyclonic motion throws the particulates onto the wetted walls of the cyclone. Water introduced into the cyclone from the top helps wet these walls and prevent dust reentrainment. The wet cyclone is also more efficient at lower pressure drops than dry cyclones, and is especially effective on coarse or heavy dusts.
The cyclone’s design allows the use of smaller-diameter liners, reducing piping and operational costs. Sizes range from massive multi-cyclone outdoor collectors affixed to buildings, to mobile units designed for use in labs. Cyclone systems can also be used to recover valuable materials from the collected dust, such as gold and silver.
The cost of a cyclone depends on performance requirements, construction materials and special features. It is also a function of the plant location, the allowable emission rate, and the nature and salvage value of the dust. The degree of dust required to be controlled will also affect the choice of a collector. Some facilities have very strict dust analysis and DHA (dust hazard analysis) specifications that may determine the need for high-efficiency, low-cost equipment such as electrostatic precipitators; moderately efficient and low-cost equipment, such as baghouses or wet cyclones; or low-efficiency, high-cost equipment, such as a dry scrubber.