One Dust Collector for the Price of Two
Industrial dust collection is almost an assumed request for all manufacturing industries. The rubber hose manufacturing process creates a broad range of airborne particulate sizes and fine smoke. Traditionally, where large and very small particulate exists in an airstream, designers would use a “pre-cleaner” cyclone ahead of a cartridge collector to knock out the heavy particulate and a secondary cartridge collector to “polish” the pre-treated airflow. That was the case, when SysTech was contacted by a Pittsburgh, PA based manufacturer with a requirement to eliminate the explosion risks associated with a hose manufacturers existing cyclone-cartridge dust collection system. In conjunction with that, we were asked to increase airflow to improve dust capture at hoods within their facility.
The Latest in Dust Collector Technology
Our solution focused on using a single dust collector with explosion mitigating components throughout the dust collection system to provide the most cost effective design. We looked at “two collectors in one” options and settled on the Donaldson Torit Downflo® Evolution (DFE) dust collector. The DFE’s revolutionary design provides several important features:
- A built-in dropout zone which pre-separates heavy dust particles before the smaller particulate is removed by high efficiency cartridge filters. The DFE is essentially a cyclone and a cartridge style dust collector wrapped into one.
- Incorporates a triangular shaped filter element, which prevents buildup of particulate on the top of the filter element.
- A filter cartridge pulse cleaning system with 27% more pulsing energy to keep the entire filter element clean.
The unique engineering design minimizes potential filter abrasion while reducing dust surface loading, which ultimately increases the lifespan of the filter elements.
NFPA Compliant Explosion Protection
The client, concerned about the explosion potential of his dust, had proactively performed a Dust Hazards Analysis (DHA) before contacting SysTech. With this information, the design was to be compliant with NFPA 654: “Standard for the Prevention of Fire and Explosions from the Manufacturing, Processing and Handling Combustible Particulate Solids”. This necessitated the need for an explosion vent, isolation valve and a rotary airlock.
The IEP Technologies explosion vent installed on the vessel was compliant with NFPA 68: “Standard on Explosion Protection by Deflagration Venting”. The vent allows explosion gases and fireball to be properly controlled and directed to a safe area away from the building and people.
To mitigate a secondary explosion, the new dust collection system included an NFPA 69: “Standard on Explosion Prevention Systems”, an IEP Technologies ProFlapPlusIII with accumulation sensor, on the DFE’s dirty air inlet duct. The passive isolation valve provides a mechanical stop gap between the explosion’s flame front and the workspace, preventing an explosion fire ball from traveling back into the building through the interconnected ductwork.
Isolation of the hopper discharge outlet was provided by an NFPA certified rotary airlock manufactured to NFPA 68 and 69 Standards, latest editions.
Improved Overall System Performance
The design goal was met with explosion protection, increased airflow and better source capture of generated dusts and smoke. So, what were the results?
- As a result of the single collector design, the end user was able to incorporate a new dust collector that was NFPA compliant, while experiencing a 40 percent cost savings on the entire project, versus retrofitting their existing dust collection system.
- Because we removed the existing cyclone pre-filter, the existing fan (which was reused) can now operate with 5” WG static pressure less resistance, resulting in a 50% increase in fan capacity.
- The increase in airflow solved the dust drop out issues in the main duct system.
- By replacing two dust collectors with one, the cost of an explosion protection system was reduced by 40% – only one collector needed explosion protection.
- The DFE model has 27% greater pulsing energy resulting in improved filter element cleaning with extended desirable filter life.
- Future capacity with the new collector – 25% increase in airflow at hoods.
- The duct system retrofit allowed use of existing system with the addition of source capture points – higher airflow and thus improved dust capture in the facility.
Results of the project were evident. Using the new technology, applied to an existing system addressed present explosion dangers and afforded an increase in dust collection system capacity. All this with a single compliant dust collector at a reduced cost!