Applying a New Test Standard to Compare Industrial Dust Collectors
The industrial filtration industry now has its first performance test standard specifically developed for pulse-cleaned dust collectors. ANSI/ASHRAE Standard 199-2016 was jointly published on June 1, 2016, by the American Society of Heating and Air Conditioning Engineers (ASHRAE) and the American Standards Testing Institute (ANSI).
Donaldson Lab Supervisor Chris Fischer was chair of the Standard 199 industry project committee and, for its final year, was instrumental in bringing the test standard to completion after a decade of development. Fischer coordinated a working group of competing dust collector manufacturers, end users, and leading test laboratories. Andrew Untz, Senior Project Engineer with Donaldson, also served on the committee for three years and was a leading contributor to the standard.
Why the New Test Standard is Important
ANSI/ASHRAE Standard 199-2016 prescribes the first laboratory test method to measure emissions, differential pressure average, and air consumption in pulse cleaned dust collectors under realistic operating conditions. It is intended to improve on Minimum Efficiency Reporting Values (MERV), a rating system developed for HVAC filters by ASHRAE 52.2, but applied to dust collectors for the last several years in the absence of more relevant test methods.
MERV filter ratings have had these limitations in the dust collection realm:
MERV ratings score the efficiency of a filter under minute, static loads, whereas dust collectors have to handle variable dust loads in high volumes. MERV ratings pertain only to the filter element, not to the entire pulse-cleaning system. MERV ratings fail to account for the fact that some dust caking is desirable for better filtration and easier cleaning. MERV ratings report a percentage of dust capture (e.g. 99% efficiency) but do not quantify actual emissions that escape the system. MERV ratings favor dense filters, which require more energy to operate and clean, and may deliver shorter filter life. For these reasons, a new dust collection performance standard was overdue. Donaldson came together with peers in the industry to fill a void and provide customers with better comparative data.
How the Test Methodology Works
MERV ratings pertain only to filter elements. While the 52.2 standard measured efficiency based on particle size, Standard 199 measures the performance of the entire system, including the air filters and the dust collector. Three major performance factors are measured in the latter stages of 48 hours of pulse cleaning, variable dust loading, and failure and recovery that mimic real-world conditions.
Here is the testing protocol:
Conditioning: Starting with a clean set of filters, the tester does an initial dust loading up to the manufacturer’s high differential pressure setting, then initiates the dust collector’s on-demand pulse cleaning system and runs the system for 4 hours. Next, to season the filters, the tester runs the collector for 24 hours, pulse cleaning at 10-second intervals.
Performance Test: Conditioning is followed by a final dust loading and another 24 hours of on-demand cleaning, which mimics how an end user would normally run the collector. All the performance data is taken from the last 4 hours of this on-demand cleaning stage, which shows compressed air consumption and average pressure drop across the filters.
Recovery Test: The final step of the test is to move into an upset condition, where the tester turns off the pulse cleaning system and continues to load up the filters to a high pressure drop setpoint of 10 inches water gauge, mimicking a failure in the system. Then the pulse cleaning is turned back on to see if the filters can recover to their pre-upset condition.
Ask These Three Questions About Your Dust Collector
When comparing new dust collectors before a purchase, ask questions about:
Emissions performance Energy consumption Filter life The performance factors are interrelated and make up total cost of operation.
What Performance Data ANSI/ASHRAE Standard 199 Reports
Standard 199 not only creates a uniform test for dust collectors; it requires a uniform report template as well. Summary data reflect performance factors that truly matter to plant engineers and operators:
Emissions in mg/m³ - Particulate matter in the vented emissions is an indication of efficiency, but capture percentage results are just a means to an end. Standard 199 measures absolute emissions performance—how much material passes through the collector during normal operation, which is more meaningful to plant managers who face regulatory and other reporting requirements.
Differential Pressure Average in Inches of Water Gauge - The energy required to move a given volume flow rate of air through a system with seasoned filters is a significant driver of operational costs. In general, the lower the average differential pressure, the less energy the system consumes. Also, lower stabilized differential pressure values generally indicate filters that will last longer.
Air Consumption in ft³/1,000ft³. Energy consumption includes fan power to drive air through the filters as well as energy to compress the air for pulse-cleaning. If a system maintains a stable filter pressure drop of 2 inches of water gauge and uses 20 percent less energy than a competitor’s system at that same pressure, it will be a real benefit to operating costs.
How Standard 199 Benefits Purchasers
There are so many applications, environments, and variables that go into the selection of a dust collector. Comparative shopping has previously been a very complicated to do. As Standard 199 reports become available on new systems, customers can do better comparative research. In the meantime, though, Standard 199 testing is voluntary, not mandated.
Donaldson is actively incorporating Standard 199 methodology into its test laboratories, with intentions to develop new dust collectors with the test standard in mind.
Leaders on Standard 199 expect it to take hold in the marketplace in the same way the previous ASHRAE 52.2 standard did—as customers see value in it and demand the data from their filtration equipment suppliers. With that push, companies supporting the industrial ventilation market will have to respond and supply the data. In the process, Standard 199 is expected to weed out low-performing dust collector manufacturers currently talking customers into unrealistic performance claims.
Meanwhile, how can plant engineers take advantage of ANSI/ASHRAE Standard 199 right away? Use the standard’s three underlying test criteria. Ask suppliers about emissions performance, energy consumption, and filter life, which are all interrelated and comprise total cost of ownership. Emissions released and total energy consumed to run a system for a year may be more relevant performance metrics to a business than a high MERV rating.
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