Explosion-Proof Dust Removal Equipment
Dust explosions are a real threat at many plants and must be controlled to keep employees safe and minimize plant damage. Explosion-proof vacuums are used in a variety of applications to remove combustible dust from heavy equipment and facility floors.
The first step in mitigating this risk is determining whether your dust is combustible through an actual sample test by a lab. After that, you can select mitigation equipment.
Venturi Scrubbers
Venturi scrubbers remove contaminants and dusts from process gas streams. They also reclaim the pollutants as fuels or process raw materials, saving industry money. They are a preferred design for applications where high collection efficiency of between 70 and 99% is required for particles smaller than 1 m aerodynamic diameter.
The polluted gas stream and wash liquid collide tangentially at the venturi throat. The resulting jets of washer fluid, typically water, are atomized by the high gas velocity and create an enormous number of tiny droplets for the dust particles to impact on and collect in. explosion-proof dustremoval equipment The entrained liquid droplets must be separated from the scrubber outlet stream by mist eliminators, mesh pads or cyclones to prevent excessive liquid carryover into the gas stream, which can reduce absorption efficiency.
Venturi scrubbing systems require very high levels of wash fluid injection rates and nozzle pressures to ensure adequate gas-liquid contact. They are also subject to severe abrasion problems in the high-velocity areas of the nozzle and throat sections. The scrubbing system should therefore be designed of wear-resistant materials, and the recirculation pump that injects the wash fluid must be constructed of an easily maintainable, leak-proof design to minimize maintenance costs.
The dusty exhaust gas enters the flanged scrubber inlet connection via ductwork from the source of emissions. Tangential feed pipes introduce the scrubbing solution supplied by a recycle pump. These feed pipes are straight open pipes that do not contain spray nozzles. The dust/solution mixture discharges out the separator bottom drain and clean gas exits through the top of the separator.
Air Classifiers
Air Classifiers are a kind of industrial machine that separates materials by size, shape and density. This process involves forces, including air drag, gravity and centrifugal force, which sort heavier particles from lighter ones and coarse material from finer particles.
They can be used for many different kinds of applications, including dedusting a powder coating; separating minerals like limestone, ores, marble, granite, talc, dolomite or barite; and even classifying toners and other industrial fillers. Using an air classifier helps reduce the need for water in settling ponds, which can save money and improve efficiency in many ways.
These devices can be incorporated into other systems, such as a grinding mill and pneumatic conveying system. In a closed circuit with a mill, they can maximize the mill’s capacity and energy output by serving as its primary sizing device instead of a separator. They are also ideal for de-dusting stone sand that has higher surface moisture (3.5 to four percent) because the moistened particles stick together and can clog up other equipment.
They are built with a hinged housing that allows easy access and cleaning, which makes them a cost-effective option for companies looking to remove dust at the source, rather than in a downstream system that can be prone to blockages. They can also be integrated with a high-efficiency particle collector to help eliminate the need for water or a settling pond and achieve the highest possible throughput rates.
Immersion Separators
For a collision repair shop dealing with aluminum parts, the combustible metal dust that accumulates can pose serious explosion hazards. That’s why NRTL-certified equipment like Ruwac’s “Wet Mix” immersion separator is necessary to help safely collect and neutralize this danger.
The aluminum dust particles entering the vacuum are instantly mixed in a turbulent liquid bath, neutralizing them and making them inert before they leave the filtration system of the separator. The separator is made from stainless steel and can be used to handle combustible dust in Group E hazardous locations.
It’s possible to integrate the immersion separator into one of Tiger-Vac’s explosion-proof vacuum cleaners or dust ignition proof industrial vacs for NFPA 484 compliance. However, it’s also available as standalone equipment that can be installed on a variety of different vacuums and industrial vacs for combustible dust and explosion/dust ignition protection.
The combustible dust is captured by the low-sparking, stainless steel filter and is rendered inert in an oil or water bath within the unit. The resulting clean air is then released into the workspace, keeping the workers safe and avoiding any potential explosions caused by combustible dust. These units are perfect for a range of industries where combustible dust is common. They’re easy to operate and are great for ensuring good housekeeping standards as required by OSHA.
HEPA Filters
In addition to dust, a HEPA filter can also trap other particle pollutants such as mold spores and pollen. It can also capture microorganisms such as bacteria and some viruses that are 0.3 mm in size. These microscopic particles are very dangerous, especially for people with asthma or other respiratory conditions.
A HEPA filter is usually made from a PTFE or glass fiber material that’s arranged as a mat of randomly positioned strands. When air flows through the filter, the explosion-proof dustremoval equipment strands separate the smaller particulates from the larger ones. When the small particles reach the strands, they’re trapped by one of three mechanisms:
As the dust settles on the filter surface, it becomes compressed until it reaches a specific pressure drop. Depending on the efficiency of the filter, the pressure drop will increase with the amount of deposited dust. Unlike some other filters, the effectiveness of HEPA filters increases as the amount of deposited dust increases.
The Tiger-Vac CD Stainless portable dust collector is an explosion-proof ductless dust collector that’s ideal for food production, pharmaceuticals, clean rooms and other applications that require pristine working environments. The air-operated industrial vacuum meets NFPA 654 standards and comes standard with 2 or 3 stage filtration that includes a pre-filter, second stage MERV 14 95% efficient ASHRAE fiberglass box filter and a true HEPA filter.
