1. S O U T H W E S T R E S E A R C H I N S T I T U T E ®
6220 CULEBRA ROAD  POST OFFICE DRAWER 28510  SAN ANTONIO, TEXAS, USA 78228-0510  (210) 684-5111  www.swri.org
SAN ANTONIO, TEXAS  HOUSTON, TEXAS  ANN ARBOR, MI  WASHINGTON, DC
July 21, 2011
Southwest Research Institute®
(SwRI®
) Technical Report Summary;
SwRI Project No. 08.16032.009, “Filter Cleanability Testing”
This Technical Report Summary presents an overview of laboratory testing conducted at SwRI to evaluate the performance of
a Diversi-Tech Green Filter Cleaning Machine under controlled laboratory conditions. In particular, the objective was to
measure if and by how much, if any, airflow resistance, efficiency, and dust capacity changed for a given number of dust
loading/filter cleaning cycles, using the Diversi-Tech cleaning machine. The evaluation was accomplished by conducting repetitive
dust loading and cleaning of a single CAT 252-5885 air filter element, provided by Diversi-Tech. The filter was tested in an OEM housing.
Testing was accomplished in accordance with procedures given in ISO 5011: 2000 (Inlet air cleaning equipment for internal
combustion engines and compressors-Performance testing). Airflow resistance was measured on the new element, as
received, and before each test run following cleaning. Airflow resistance was determine by measuring filter restriction as a
function of air flow rate over a given flow range of interest. During testing, the new filter element was initially loaded to 20" of
water restriction, and then cleaned by a Diversi-Tech technician using the Diversi-Tech Green Cleaning Machine, which had
been relocated to SwRI for this test project. The filter was reloaded and re-cleaned in the same manner, for a total of four
cleanings, thus a total of 5 dust loadings were accomplished so that filter performance could be evaluated initially and after
each cleaning. Dust loading was accomplished at a steady airflow rate of 2800 cfm, using ISO 12103-1, A2 Fine Test Dust at a
concentration of 1 g/m
3
air (0.028 g/ft
3
air). Initial and cumulative efficiency were measured during each dust loading cycle.
The element was inspected before and after each cleaning and dust loading event.
Primary findings are as follows:
 No degradation of the filter element or the filter media was observed after 4 cleanings
 No loss of filtration efficiency was observed after 4 cleanings (In fact, initial and cumulative efficiency
increased slightly)
 Overall restriction increased by 0.71 inches of water (8.6%) after 4 cleanings.
 Total amount of dust loaded 103.8 lbs
Dust removed from filter per cleaning:
 Dust loaded first cleaning: 25.34 lbs, dust removed first cleaning: 22.60 lbs (89.2%)
 Dust loaded second cleaning: 20.90 lbs, dust removed second cleaning: 18.30 lbs (87.6%)
 Dust loaded third cleaning: 20.35, dust removed third cleaning: 20.00 lbs (98.3%)
 Dust loaded fourth cleaning: 19.85 lbs, dust removed fourth cleaning: 19.70 lbs (99.2%)
 Total dust removed after 4 cleanings: 80.60 lbs (93.3%)
 Increase in overall element dust capacity (with 4 cleanings): 310%
Printed with Permission from SwRI, July 21, 2011