Dust collection systems are used by industrial and manufacturing companies all over the world to improve air quality in the work environment.
Dust collection systems are used by industrial and manufacturing companies all over the world to improve air quality in the work environment. In addition to providing clean air for employees, dust collectors extend the life of industrial equipment, improve product quality, reduce running costs and boost plant productivity.
Since the early 1980’s workplace health and safety has been a prevalent concern among industrial manufacturing sectors known to produce large amounts of dust and airborne particulate matter (PM). Continued and repeated exposure to dust and particulates can permeate into an individual’s lungs and bloodstream, which can cause several health and environmental hazards.
To implement the right dust collection solution for your facility, it’s important to understand the wide-reaching effects of industrial dust to your business and the short- and long-term repercussions to human health. Furthermore, it is important to know that several commonly produced dust and fumes have in recent years been proven carcinogenic. Your dust and fume control system serves to protect both human health and the business against future claims and litigation.
To mitigate all of these risks, companies use specially designed dust collection systems to remove dust and particulates from the air stream.
Industrial dust collectors are designed to prevent dust and particulates from entering the workplace and surrounding atmosphere. These large-scale air pollution control devices are appropriately designed to improve air quality, reduce health risks, and mitigate environmental hazards unique to the application and work environment.
The necessity of a dust collection system, for the most part, will be driven by the industry itself. Applications that commonly use dust extraction systems include:
When planning a new dust collection project or making modifications to your existing system, it’s best to have an understanding of what your local or state guidelines require. Consulting an expert can help ensure you are in compliance.
All levels of government are involved in managing air quality in New Zealand. The New Zealand government has established national environmental standards to identify and prioritise air quality needs. States and territories are responsible for monitoring and managing air quality in their jurisdiction.
States monitor and compare their air quality standards against national ambient air quality standards established by the National Environment Protection Council. Environmental agencies within each state and territory are responsible for:
Seven key air pollutants to which most New Zealanders are exposed include:
In New Zealand, regional councils and unitary authorities measure outdoor air quality in their regions under the Resource Management Act 1991. The National Environment Standards for Air Quality are regulations that set limits in outdoor air for PM10, carbon monoxide, nitrogen dioxide, sulfur dioxide and ozone.
Air pollutants measured in New Zealand and reported on the Land, Air Water Aotearoa (LAWA) include:
To learn more about National Air Quality Standards by region, visit:
Industrial dust collection systems are engineered to draw in and filter airborne dust particles and debris. A dust collector will first capture dirty air, separate the matter either by passing air through filtration media, or through another source of energy, and then discharge the purified air back into the environment.
Understanding the differences between the many dust collection systems on the market today is often challenging as there are many types and styles to choose from. Dust collection systems design and construction can vary depending on the type of dust collector and include the following:
Important!
Not all dust collection methods and technologies are suited for all applications. A certain separation, media or cleaning technology is design for a certain application. A suboptimal product spec can result in poor performance, product failures and commonly in frequent bag changes and high running cost.
Cyclone dust collectors use centrifugal force to separate air and materials. The force pulls dusty air into a scroll type inlet forming a cyclonic motion. The vortex within the dust collection chamber flings large dust particles toward the outer walls of the dust collection chamber. Once the particles reach the outer walls, gravity and friction force the larger particles to descend into a receiver. The filtered air and fine particles then leave the collection chamber through the internal vortex tube.
Cyclone dust collectors are most commonly found in facilities where fibrous dust is managed, such as:
Cyclone dust collectors are often used as pre-filters for other types of dust collection systems including pulse jet dust collector and cartridge collectors.
Large, irregularly shaped particles often generated at these facilities are known to clog fine dust collectors, such as baghouse and cartridge filters. Using a cyclone dust collector as a pre-filter helps:
Your dust collection manufacturer engineering team will help customize the cyclone dust collector system to fit specific application needs.
They will take into consideration the following five factors:
An electrostatic precipitator (ESP) removes pollutants from a gas stream by using the force of an induced electric charge to charge the particles in the gas stream.
These charged particles are then drawn to collection plates with the opposing charge where they accumulate. The remaining air passes through the plates unimpeded. Once the collection plates are full, the particulates are shaken off the collection plates using mechanical rappers.
The particulates, wet or dry, are shaken into a hopper and are transported away by a conveyor system for disposal or recycling.
Electrostatic precipitators are highly effective at removing particle pollution. Some ESP’s can:
ESP are used in smokestacks and other flues most frequently at industrial facilities and power-generating stations. They are often combined with denitrification units to remove nitrogen oxides and scrubbers or other devices to remove sulphur dioxide.
ESP are also used in various industrial and household applications:
Industries that use ESP include:
An experienced engineering team will help determine the size and type of ESP required for specific processes.
ESP are designed to work on gas streams with specific temperature and moisture characteristics. Dry ESPs, most commonly used, operate above the dew point of the gas stream. Wet ESPs operate with saturated airstreams that have 100% relative humidity. The main difference between the two classifications is how their collector plates are cleaned.
The performance of ESPs is affected by particle resistivity.
ESP are not used to control gaseous emissions. ESP have a large footprint and a high initial cost, but they have low operating costs, a long service life and typically require minimal maintenance.
The design of the ESP system is normally completed by the manufacturer who takes into consideration many variables including:
Wet scrubbers remove particulates, vapours, odours and gasses from industrial exhaust streams by introducing a liquid, typically water, into the stream. The liquid cools the gas flow and collects particulates and gasses through agglomeration, adhesion and/or encapsulation.
Wet scrubbers are commonly found at Petroleum Refineries, Chemical Processing Facilities, Acid Manufacturing Plants and Steel Manufacturing Companies.
Wet scrubbers differ in how they expose the exhaust stream to the liquid scrubber.
The main disadvantages of wet scrubbers include:
An experienced engineering team will take many factors into consideration when choosing the best wet scrubber system for a specific application.
A few of these considerations may include:
Dust collection systems require ongoing maintenance after installation. Consideration should be paid to the long-term maintenance cost of a new system and how to engineer a solution that will reduce long term maintenance costs. A reputable dust collection engineering firm will also provide an aftercare service that will provide:
There are several types of dust collection systems that use filter media to remove dust particulate from the work environment. These include shaker, reverse air, and pulse jet systems. Pulse jet are the most common and include baghouses, cartridge collectors and bin vents.
Shaker Style dust collectors use woven filter bags which are hung and tensioned from the top of the filter housing and attached with an open bottom to a tube sheet.
A shaker baghouse is designed so that when an airstream enters below the filter bags it is pulled upwards and through the interior of the bags. Once sufficient dust cake builds on the inside surface of the filters, they can be cleaned by mechanically shaking the filters until the dust falls into a hopper system below the dust collector. Finally, clean gas is exhausted towards the top of the collector.
Shaker baghouses can be used in facilities where there is no compressed air available and are most suitable for applications where the baghouse will experience lighter dust loads and only run for shorter periods of time, i.e., > 4hours between shut down cycles.
A reverse air baghouse can be used in large scale air handling applications. These systems require specialty fabric filter bags, which typically consists of a compression band top with a cap and hook. The bottom filter bag configuration can vary from a compression band, double beaded snap band, or corded.
This style of dust collector accumulates dust in a similar way to a shaker baghouse. Dirty airstream enters the baghouse, then it’s pulled through the bags from the inside. The difference in a reverse air versus shaker is in how filter bags are cleaned.
Once dust cake is accumulated on the inside surface of the filter bags, cleaning is accomplished by injecting clean air into the system in a reverse direction. This action pressurizes the compartment, which allows the filter bags to partially collapse, and the dust cake to fall into the hopper located below. In general, reverse air baghouses can generate a lower cleaning air pressure versus the compressed air pulses of a pulse-jet. This makes the reverse air technology suitable and cost effective in some applications while unsuitable in others. Engage a reverse air specialist for advice.
Common applications that use reverse air dust collector include:
The main disadvantages of reverse air filters include:
A pulse-jet dust collector may be one of the most common styles of dust collection systems used across various industries. A pulse-jet baghouse differs in the way a shaker or reverse air will collect dust. In a pulse-jet, dirty airstream flows through from the outside to inside the filter bags, finally expelling clean air through the top of the system.
To clean dust that accumulates outside of the filter bag, a blast of compressed air is injected through a blowpipe via a venturi over each row of filters. This short blast of compressed air breaks up the dust cake that has accumulated on the outside of the filters and allows dust to fall into a hopper below.
Pulse-jet dust collectors use a bag and metal cage arrangement. For a top-load baghouse, the most common filter bag configuration is a double beaded snap band top and disc bottom. Bottom load baghouses use raw top disc and bottom filter bags.
Pulse-jet baghouses help reduce the re-circulation of dust because they have a short cleaning cycle. In comparison to a shaker or reverse-air baghouse, filter bags in a pulse-jet will receive more thorough cleaning and reconditioning.
A pulse jet baghouse dust collector is an excellent choice for industries with heat, moisture, fibrous particulates and/or heavy dust loading applications. With a large variety of fabric filter media, baghouse dust collectors are the preferred choice for handling a diverse range of applications including heat, sparks, acidic gases, fibrous dust and grain dust. Common applications for baghouse dust collectors include:
Many air pollution control companies apply one pulse jet design to many applications. This “one size fits all” approach can make it challenging to meet operational goals. Because every application is unique, it’s best to partner with an air pollution control firm that can custom engineer a solution specific to your application. Customisation is crucial to achieving optimal performance while lowering long term maintenance costs. Some of the most important aspects of designing a custom baghouse are:
Cartridge dust collectors are used in applications like bulk powder, grinding, foundries, welding and more. These systems are ideal for nuisance dust, smoke, fumes, or applications with fine dust particulates of .5 micron or less. A cartridge dust collector is also ideal when there are height and space restrictions, small or moderate dust loads, and airflow temperatures below 118 Degrees Celsius.
This type of dust collector uses cartridge filters, which has multiple advantages over a bag and cage system of a baghouse. The advantages of cartridge filters are:
The primary disadvantage of using a cartridge dust collector system is that if it is not specified correctly, they are prone to rapid failure. Cartridges are not designed to efficiently eliminate any significant volumes of dust and particulates. If you are producing large volumes, for example, more than 208 litres of dust a day, we recommend scaling up to a baghouse.
Cartridges can be expensive to replace and will require frequent replacement if applied in incorrect application or with too high a filtration velocity.
Characteristics of an incorrectly dimensioned or applied cartridge dust collector include its rapid filter failures, poor performance and it is expensive to run/maintain.
Bin vents are small dust collectors designed to filter air in loading environments that work with products such as sand, cement, or grain. Bin vents can be used with silos and tanks, thereby creating a process that allows displaced air to be ventilated without losing product.
Similar to cartridge collectors, bin vents are compact and designed to handle low volumes of dust. The advantages of using a bin vent system and pleated filters are:
Static filter baghouse and reverse airflow dust collectors are usually considered for small to medium dust loads with no high temperature requirements. Systems can cost between $5k to $50k and can handle airflows from 2,000-16,000m3/h. Key features you should look for in a small – medium dust collector are:
Shaker dust collectors with combustible dust safety components cost between $18k to $45k. They are modular in design, and can handle airflows between 3,000-14,000m3/hr. Features include:
Large dust collection systems include custom-engineered shaker, pulse-jet or reverse air dust collector. Used for large scale processing, these systems can cost $50k to $150k and be designed to handle airflows of 16,000-60,000m3/h. Some larger engineered systems can cost more than $1million. Key features you should look for in a large dust collector are:
Dust collection systems that require filter media to remove dust particulate include shaker style, reverse air, and pulse jet style systems.
Filters come in a wide range of configurations depending on the type of dust collector you operate.
Cartridge filters are generally designed in a cylindrical form. They’re far more compact than a filter bag and cage system, and easy to maintain as well as replace. There are three common medias used for cartridge filters:
Cartridge Treatments: Common treatments for cartridge filters include PTFE (Teflon) and fire retardant. Other treatments that can be used on Spunbond and Polyester cartridge filters are anti-static and hydro-oleophobic coatings. Using a specific treatment on cartridge filters can help increase the efficiency rate of dust capture. For example, if an application has dust that is viscous, adding a PTFE membrane onto spunbond polyester allows dust and particles to adhere far better.
Cartridge Configurations: Cartridge filters are typically cylindrical. However, some manufacturers make oval or conical shaped cartridge filters. The configuration of your cartridge filter is ultimately dependent on the design of your cartridge dust collector. The most common configurations are:
Industrial filter bags are used in dust collection systems such as shaker, pulse-jet, and reverse air baghouses. The right filter bag media, treatment and configuration will depend on factors such as dust characteristics, application, operating temperature, and dust collector style. There are several filter medias available, but the most common include the following:
In addition to selecting the right filter bag media, there are a variety of treatment options available that may help improve dust cake release, deliver consistent airflow, and lengthen the life of your filter bag. The right treatment for your filter bag will be dependent on your dust characteristics and application. Treatments can include:
Your filter bag configuration depends on the style of baghouse you have; whether it’s a shaker, pulse-jet, or reverse air. In pulse jet systems, bag configuration will also depend on whether you have a bottom load or top load system The most common configurations for each style of baghouse are:
Pleated filters and pleated bags are terms that are used interchangeably. Pleated filters are commonly used in bin vent dust collectors. But, depending on your type of dust collector and application, you may be able to convert a bag and cage configuration to a pleated system. Advantages of converting to a pleated filter system include a lower air-to-cloth ratio, increased efficiency, extended filter life, reduced inventory, and lower maintenance costs.
Media for pleated filters includes Spunbond Polyester, Polyester, Polyester with PTFE, and Aramid. The least common of these is Aramid because it’s normally reserved for high-temperature applications, which comes at a higher cost.
The configuration of a pleater filter can often improve efficiency and can be more durable than a conventional filter bag. Pleated filter configurations will depend on the style of dust collector; top load or bottom load. Common configurations are:
A dust collector is a significant and important investment for your business – making it critical to get it right the first time.
When working with the dust collection supplier that will help you design and manufacture your system, it’s important to understand the many variables that go into the design process and how they affect overall costs and long-term performance. The most critical factors in designing the right dust collection system that will provide optimal performance long term include:
The first step in the design process is to assess the dust properties of your application. This includes size, density, the temperature at which you operate, the abrasiveness of the dust, chemistry, whether moisture is present, and combustibility. Your dust collection engineering and manufacturing firm can help you adequately assess each of these variables and identify the right dust collection solution based on your unique dust properties.
Calculating the right volume for a dust collection system during the design process will minimize long term maintenance expenses and ensure optimal dust capture. When volume is too low and unable to capture dust efficiently, air quality decreases, along with the lifespan of wearables and the system itself. If the volume of your dust collection system is too high, energy intake increases and can raise overall operation costs.
Beyond the application and dust loading rates, a dust collector’s size can be determined by space restrictions in the work environment. For example, if a dust collector is required inside of a building, a top load system may not be ideal since servicing the system is performed from the top of the unit.
When engineering a new system, it’s critical to consult your local, state and national regulations for specific requirements unique to your application and work environment.
Environment location and local climate help determine filter media selection, fan size, and whether special coatings or insulation for the system is needed to protect it from extreme weather.
Build-up of combustible dust in a work environment poses significant risks that will need to be addressed from the beginning of your dust collection project. As you work together with your air pollution specialists to design your system, the type of dust and the amount you produce will be considered. Combustible dust is present in applications such as food processing, cement, woodworking, and metals. Increased combustibility is also heightened when dealing with fine dust particles because there is a higher ratio of surface area to volume.
If your application is susceptible to combustible dust, an explosion venting strategy may be considered to both mitigate any serious fires or explosions from happening. Common venting strategies include explosion latch, no return valve, explosion vent or panel, abort gate, and a spark detection system.
No matter the size of the endeavour, budget is always top of mind when pursuing a new dust collection project. But regardless of the price point, you should expect the air pollution specialists you work with to properly size a dust collection system that will deliver perfect performance. In terms of budget, the size of your system will influence overall costs.
All dust extraction systems are different and cost will vary depending on size, space requirements, temperature considerations, ease of maintenance, emission control requirements and many other factors.
Note: under-sizing a dust collector to save cost will likely result in poor performance, rapid failure and high running cost.
A project that delivers a custom dust collection system should be designed to provide ongoing high performance, long-term savings on maintenance, while also ensuring a clean environment for your facility. Custom systems often consist of multiple units of various types of dust collectors used to capture dust at different places in your work environment. These can include a combination of wet scrubbers, ESPs, cyclones, pulse-jets, reverse-air, bin vents or cartridge dust collectors.
Considering preventative and on-going maintenance costs is an essential part of investing in a dust collection system. As your dust collector ages, parts wear and tear and require maintenance or replacement. Key factors that will minimize long-term maintenance costs are:
Preventative maintenance allows you to keep wearables in good condition, identify issues, and address concerns before they become larger problems. Issues such as clogged filters, leaking pulse valves, and reduction of suction at pick-up points can all lead to an unscheduled plant shutdown. These maintenance issues may end up costing you thousands of dollars, if not more, in lost production or regulatory fines.
To keep your pulse jet dust collection system performing at its best, the team responsible for maintenance should be watchful of the 5 most wearable parts of a pulse jet dust collector.
Filters: Signs filters may need replacement can range from excessive dust cake build up on the filter itself, loss of suction at pick-up points, or a high differential pressure reading.
Pulse-Valves: The life of a dust collector’s pulse-valves may be coming to an end if it stops pulsing, emits a weak pulse, has a crack on the housing, has visibly stripped or damaged threads, or if your filters are not being cleaned well.
Diaphragms: Diaphragm kits are small but play a vital role in the operation of a valve. If the kit’s spring is broken, if you experience increased differential pressure, or if there is weak pulsing then it may be time to check your diaphragm.
Solenoids: A solenoid may need to be replaced if its plunger is tarnished, its post is crooked, or the rubber on the plunger is tattered.
Timer Board: Signs a timer board may be at the end of its life are no power coming to the board itself, valve isn’t pulsing, or a small electrical charge from the timer board is causing weak pulsing.
Part of a well-rounded preventative maintenance schedule will be ensuring that wearables are checked either daily, weekly, monthly, or yearly. Below is a general recommendation for pulse jet dust collection systems. Please note that this schedule may vary depending on your system and application.
Weekly:
Monthly:
Yearly:
It’s essential to find a dependable and responsive air pollution control firm to engineer and fabricate your dust collection system correctly the first time. Proper dust collection engineering will minimize long-term maintenance costs, thereby reducing risks that create unscheduled shutdowns. For your next dust collection project, consider these qualities and characteristics that separate an exceptional air pollution specialist from an average one.
Experience: Your air pollution control company should specialize in and have engineering experience designing, installing and maintaining air pollution control equipment across a broad range of applications and industries.
Quality: High-quality products built to perform and provide peace of mind throughout the life of the product. The company you work with should be able to deliver a high degree of customization, where needed, while also ensuring a high-performance solution that can be delivered quickly and cost-effectively. Most importantly, your air pollution control firm should be focused on designing a system that will perform adequately long term.
Responsiveness: An exceptional air pollution specialist will have a dedicated department providing customer service. In addition, common spare parts should be readily available to minimize any production losses or emergencies.
Our approach to solving our customers’ dust collection challenges is our experience engineering quality, and custom solutions at an unrivalled cost to value point while also providing extensive aftercare service solutions We aim to take care of our customers over the entire course of ownership – not just during the engineering and installation phase.
Airtight Solutions is one of the largest specialist air pollution control companies operating in New Zealand. We have extensive experience with a verifiable track record of successful applications. This strong reputation is built upon decades of supplying well-engineered systems.
To better serve our customers, Airtight Solutions is structured into four divisions. Dust and fume control, aftercare servicing, engineered solutions, and waste reduction/waste to energy. Airtight draws upon the individual strengths of these divisions when providing an effective solution to the requirements of a pollution control project. This is the Airtight difference that ensures high-performance solutions can be delivered quickly and cost-effectively.
Are you planning for a plant expansion, new facility or system modification project? We would love to be a resource for you and help you engineer a solution that will help you maintain a safe, productive and low maintenance work environment for years to come. Schedule your consultation with an Airtight Solutions engineer today.
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