Bulk Solids Conveyors for Combustible Dust and NFPA 652

January 3, 2018

The presence of combustible dust is a recognized hazard in many facilities. While most facilities are aware of the dangers and take steps to manage this hazard, the publication of the NFPA 652 standard in the USA has now brought combustible dust under regulatory control. This move has significance for those seeking to buy and install bulk solids conveyors for combustible dust applications.

What is the NFPA Combustible Dust Standard?

In October 2015, the National Fire Protection Association (NFPA) published the NFPA 652 document: Standard on the Fundamentals of Combustible Dust (2016 edition). In publishing the standard, the NFPA sought to address the lack of appreciation and understanding of combustible dust hazards in industry. The NFPA 652 standard introduced a new term, Dust Hazard Analysis (DHA). DHA is aimed at facilities whose processes generate combustible dusts collected by simple dust collectors.

The NFPA 652 standard rolls up the guidelines and standards that NFPA previously issued for various industries and applications, including NFPA 61 (Agricultural and Food Processing), NFPA 654 (Manufacturing, Processing and Handling of Combustible Particulate Solids), NFPA 664 (Wood Processing and Woodworking Facilities), etc. By aggregating these various guidelines and standards, NFPA 652 now becomes the primary industry standard for combustible dust.

How does NFPA 652 differ from Process Hazard Analysis?

WithIn industries whose processes generate combustible dust, such as refining and chemical manufacturing, it has been common to conduct a Process Hazard Analysis (PHA) to analyze and manage the risk. The NFPA 652 standard provides a detailed guide for conducting a hazard analysis on a dust collection system in its appendix. The standard also contains retroactive requirements for implementing a DHA. Currently, within the USA, existing systems are required to have a DHA, and the time limit to perform this analysis is three years from the date of issuance of the standard, October 2015.

How does NFPA 652 differ from OSHA regulations?

The term “Dust Hazard Analysis” in NFPA 652 can be distinguished from the more complex Process Hazard Analysis noted above that is required by the OSHA Process Safety Management (PSM) program for the chemical process industry. NFPA 652 does not supplant existing OSHA regulations. The purpose of NFP 652 is provide personnel with a single source of information on the fundamentals of safely handling combustible dust and powders in an industrial setting.

How can companies use bulk solids conveyors to help manage the risk of combustible dust?

OSHA regulations contain valuable guidance on controlling the presence of fuel (dust) which could lead to a combustible incident. OSHA guidance centers on controlling three factors:

  • Capturing dust before it escapes into a work area. This involves the use of approved and properly designed and installed dust collection systems.
  • Containing dust within equipment and systems that are built and operated to safely handle combustible dust.
  • Cleaning work areas, surfaces and spaces thoroughly using safe housekeeping methods to remove any combustible dust that cannot be captured or contained.

What are the equipment options for bulk solids conveyors for combustible dust?

Handling combustible dust is a critical service application. Bulk solids conveyors for combustible dust are especially designed to allow the dust to be capture or contained, preventing its release into the surrounding space.

At UniTrak, our equipment lineup includes the following bulk solids conveyors for combustible dust:

  • TipTrak Monocoque bucket elevatorsTipTrak™ Monocoque units are explosion-resistant and especially designed to service critical service applications involving the presence of combustible dust. TipTrak™ Monocoque units are fully sealed, ensuring zero fugitive emissions of combustible dust from inside the elevator. As with the PEC model described below, direct connection to a facility’s dust collection system is supported.
  • TipTrak PEC bucket elevatorsTipTrak™ PEC fully enclosed elevators support direct connection to a plant’s dust collection system, allowing dust generated in conveying to be captured. The fully enclosed design helps to contain any uncaptured dust within the elevator.
  • Powderflight aeromechanical conveyorsPowderflight aeromechanical conveyors work on the principle of a fluidized airstream. Because no additional air is required to convey material through the conveyor, there is no excess air at the conveyor outlet to filter for dust. However, careful consideration must be given to controlling dust that may arise from discharged material impacting the sidewalls of the discharge bin. In these applications, UniTrak can provide an appropriate solution to ensure that any combustible dust generated is safely controlled.

The presence of combustible dust should never be taken lightly. Current OSHA regulations and the NFPA 652 standard make it more important than ever for companies to ensure that they are actively managing the risks involved with critical service applications involving the presence of combustible dust. For companies seeking proven conveying solutions for critical service applications involving combustible dust, UniTrak is your preferred equipment partner. To fund out more about how our bulk solids conveyors for combustible dust, contact our sales team directly.

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