Dust Collectors – How to Efficiently and Effectively Clean Your Industrial Environment
Pure, clean air is critical within industrial environments to ensure workers health and safety. Many industries such as woodcutting, furniture building, plastic cutting, metal working, welding, among others operate under conditions that create a lot of dust and smoke.
Dust collectors are devices that filter dust from polluted air generated by industrial processes and discharge clean air into the environment. Efficient dust collectors protect employees from dry particulates and pollution in the air.
There are a variety of dust collectors on the market that efficiently treat polluted air. The most commonly used ones are electrostatic dust collectors, baghouse collectors, cyclone dust collectors, air washers & wet gas scrubbers, and cartridge dust collectors. We will discuss how each works and the best usage for them.
Electrostatic dust collectors use electrostatic charges to separate dust from the air. High voltage, direct current electrodes (carrying negative charge) are placed between grounded electrodes (carrying positive charge). The dust borne air stream is passed through the passage between the discharging (negative) electrodes and collecting (positive) electrodes. Dust particles receive a negative charge from the discharging electrodes (ionizing section) and are attracted to the positively charged grounded electrode (collection plates) and fasten on to it. Cleaning is done by rapping or vibrating the collecting electrode wherein dust particles fall away. This type of collector does not work well around heavy dust producing machines and processes because the source capture area fills up quickly in this type of environment.
Baghouse Collectors (or Media Filtration Collectors): Filter media is used to filter out dust particles from polluted air by using a screening material, such as fabric, in the path of the air stream. Dust particles collect on the screen, forming a thick coating that increases in thickness as time goes by, thus making the filter media more efficient. The problem with this type of collector is that the dust particles can combust, causing fires. Also, the filter media has no effect on bacteria and mildew. Another problem has to do with pressure drop where the screening material slows down the air as it tries to pass through.
Cyclone Dust Collectors are large funnel shaped tubes connected to ducts often used in woodshops, machine shops, manufacturing plants, and powder processing plants. Dust and debris are sucked in at the top. Air containing fine dust blows out of the other side of the top, while chips and large dust particles fall out of the bottom into a drum or bin. Dusty exhaust air is either blown outside or filtered again using media filtration. The efficiency of Cyclone Dust Collectors is limited, so they are typically used as pre-cleaners for collectors with greater efficiencies. Often finer dust particles are swept back into the environment because they don’t collect properly on the collecting surface.
Air washers or wet scrubbers, use liquid (usually water) to absorb the finer dust particles (scrubbed). Water comes into contact with the dust filled air stream and captures dust in water droplets. The dirty water droplets accumulate, and are collected and removed. The cleaned air in air washers contains fine water droplets forming a mist. These water droplets can be removed from the cleaned air by a mist eliminator. Wet scrubbers have low capital costs and require small spaces to install. They can be used to treat high temperature and high humidity air streams and have the capability to capture both air and sticky particulates. However they have high operating costs, require a pre-cleaner for heavier dust loadings, cause water pollution and are likely to erode at high velocities.
Cartridge Dust Collectors use a perforated metal cartridge with a cellulose filter pleated, non- woven filter media, bound by steel caps at the top and bottom. The pleated design provides greater amount of filtering area while occupying lesser space. Cartridge Dust Collectors are highly efficient in the collection of dust with high bulk densities and fine dust particles. Filter cake forms well at low-pressure drop and has high filtration efficiency. In a study conducted by the American Foundry Society, it was found that the outlet dust flow in cartridge collectors was the least in comparison with other dust collectors in foundry operations.
The Clean Air Brahm™ series is a next-generation, variable-sized, cartridge dust collector that features high efficiencies that are particularly important for applications involving toxic dusts or where air is being re-circulated. These compact collectors range in size from 2-108 cartridges and 1000 – 80,000+ CFM (cubic feet per minute). The Clean Air Brahm™ collector is superior to all other designs out on the market due to it’s unique combination of features and benefits, such as filters positioned vertically with pulsing from the bottom using an enhanced, updated Down-Flow Technology. The Collector also features a 50% better filter lifetime versus other vertical style collectors and 75% better filter lifetime versus horizontal designs. Plus, the Clean Air Brahm™ Collector has the lowest overall TCO (Total Cost Of Ownership) on the market.