Effective combustible dust removal
When a facility has multiple areas where combustible dusts are present, are central vacuum cleaning systems the only option?
Responding is Doan Pendleton, president, VAC-U-MAX, Belleville, NJ.
Traditional central vacuum cleaning systems are custom-engineered systems designed for continuous operation to remove large volumes of materials and can accommodate one to 20 operators simultaneously through strategically placed tubing networks.
These centralized vacuum cleaning systems – used in coal plants, grain processing facilities, food and pharmaceutical processing plants, chemical manufacturing facilities, and just about any other industry that handles bulk solids and powders – make it easy for operators to efficiently remove combustible dusts before they have a chance to accumulate to dangerous levels.
For many organizations, central vacuum cleaning systems are cost prohibitive. Traditionally, larger central vacuum cleaning systems are located outdoors and require a bag house with either a chemical suppression system or an explosion venting system to meet OSHA and National Fire Protection Association standards. In addition, outdoor air permits and construction permits are common requirements when installing a central vacuum cleaning system outside of a facility.
Fortunately, a wide variety of combustible dust vacuum cleaners afford employers the same ease and efficiency of mitigating dangerous accumulations of combustible dusts as central vacuum cleaning systems at a fraction of the cost – and without longer lead times to get a combustible dust abatement program up and running.
The alternatives to traditional large-scale central vacuum conveying systems for combustible dust include small-footprint stationary vacuum systems that meet NFPA guidelines for use indoors, portable intrinsically safe compressed-air-powered combustible dust vacuum cleaners and portable explosion-proof electric units that operate with smaller piping networks located throughout the facility.
For some facilities, a single, small-footprint stationary vacuum cleaner will suffice, while others may need a small fleet of portable air-operated vacuum cleaners strategically located throughout the facility.
For sprawling facilities where a central vacuum cleaning system would need to be excessively sized to effectively vacuum from one end to the other, an explosion-proof breakaway central vacuum cleaning system offers both the flexibility of a single-operator portable vacuum and the benefits of more traditional central vacuum cleaners.
These portable units aren’t like over-the-counter shop-type vacs or industry-specific vacuums that are more for commercial use and lack the robustness needed in a rugged industrial environment.
Combustible dust vacuum cleaners aren’t commodity items, and it’s important to consider down-the-line costs such as reliability, maintenance, filter life, ease of use and energy costs. If vacuum cleaning systems aren’t easy to use or filter cleaning is a hassle, operators are less likely to use them as often as needed.
When filters aren’t robust, replacement will be more frequent, increasing costs throughout the life of the equipment. Energy costs, especially in terms of intrinsically safe compressed-air-powered vacuum cleaners, can – within a few months of use – eliminate any savings from initial investment between one manufacturer and another when facilities don’t factor SCFM into the equation.
Compressed-air-powered vacuum cleaners are ATEX tested and certified; meet NFPA 77 requirements; and are the first-line offering for Class II, Division 2 environments.
Editor's note: This article represents the independent views of the author and should not be construed as a National Safety Council endorsement.