Contamination Control Contamination Control in in Dynamic - PowerPoint PPT Presentation

Contamination Control Contamination Control in in Dynamic Operating Environments Dynamic Operating Environments Charlie Juhasz Charlie Juhasz Technical Director Technical Director Scientific Services Scientific Services SSI SSI Inc. Inc.

Why Contamination Control ? Why Contamination Control ? Contamination determines life cycle cost Contamination determines life cycle cost  Wear rates, service life Wear rates, service life   Reliability, Mission Readiness Reliability, Mission Readiness   Maintenance costs Maintenance costs   Operating costs Operating costs  SSI SSI

Contamination Control Contamination Control  Starts with system design Starts with system design   Involves every component Involves every component   Cannot be accomplished by filtration alone Cannot be accomplished by filtration alone  SSI SSI

Requirements for effective Requirements for effective contamination control contamination control  Design optimized for contamination control Design optimized for contamination control   Design optimized for the intended function Design optimized for the intended function   Clean components before assembly Clean components before assembly   Clean assembled system (roll off cleanliness) Clean assembled system (roll off cleanliness)   Filtration optimized for dynamic operations Filtration optimized for dynamic operations  SSI SSI

Characteristics of Modern Characteristics of Modern Hydraulic Systems Hydraulic Systems reservoir volume (relative to flow rate) Small reservoir volume (relative to flow rate)  Small  of the fluid in the system is in constant Most of the fluid in the system is in constant  Most  recirculation recirculation output adjusts to system demand Pump output adjusts to system demand  Pump  cycle includes random flow changes; Duty cycle includes random flow changes;  Duty  low, and zero flow. low, and zero flow. SSI SSI

Characteristics of Modern Characteristics of Modern Hydraulic Systems Hydraulic Systems  Contamination level in the fluid is not Contamination level in the fluid is not  homogenous and varies throughout the duty homogenous and varies throughout the duty cycle cycle  In normal operations, volumes of cleaner fluid In normal operations, volumes of cleaner fluid  are intermingled by volumes of more are intermingled by volumes of more contaminated fluid contaminated fluid  All components in a re-circulating system will All components in a re-circulating system will  be exposed to contaminants released by any be exposed to contaminants released by any of the components, including the filter of the components, including the filter SSI SSI

Contamination in a Hydraulic Contamination in a Hydraulic System System  Average contamination levels determine wear Average contamination levels determine wear  rates rates  Maximum contamination levels cause operational Maximum contamination levels cause operational  failures failures  Operational failure occurs when the contamination Operational failure occurs when the contamination  level exceeds the tolerance threshold of a critical level exceeds the tolerance threshold of a critical component component  Sensitive components are at risk when they are Sensitive components are at risk when they are  exposed even to short periods of increased exposed even to short periods of increased contamination contamination SSI SSI

Contaminant Sensitivity Contaminant Sensitivity Sensitive components will fail when their contaminant Sensitive components will fail when their contaminant tolerance level is exceeded, regardless of the length tolerance level is exceeded, regardless of the length of time they operate in a clean environment of time they operate in a clean environment SSI SSI

What do filters do? What do filters do?  Capture Capture some some of the built in, of the built in, ingressed ingressed, or wear , or wear  generated contaminants generated contaminants  Do not retain Do not retain all all of the captured contaminants of the captured contaminants  SSI SSI

Total Filter Performance Total Filter Performance and Fluid Cleanliness and Fluid Cleanliness Contamination level in the fluid downstream Contamination level in the fluid downstream of the filter is a function of: of the filter is a function of:  Capturing Efficiency Capturing Efficiency   Retention Efficiency Retention Efficiency  SSI SSI

Rating Filters Rating Filters Filters must be rated for their ability to Filters must be rated for their ability to control contamination, and maintain it and maintain it control contamination, below the specified maximum during the during the below the specified maximum entire duty cycle entire duty cycle SSI SSI

The Multipass Test The Multipass Test  Re-circulating system (Closed Loop) Re-circulating system (Closed Loop)   All contaminant passing through the filter is returned All contaminant passing through the filter is returned  to the filter to the filter  Full flow through the filter Full flow through the filter   Constant challenge (contaminant injection constant Constant challenge (contaminant injection constant  relative to the flow) relative to the flow)  All contaminant injected is accounted for either in the All contaminant injected is accounted for either in the  filter, or suspended in the fluid filter, or suspended in the fluid SSI SSI

Filter Tests and Ratings Filter Tests and Ratings  The ISO 16889, it The ISO 16889, it’ ’s predecessor ISO 4572, ISO DIS s predecessor ISO 4572, ISO DIS  23369, MIL PRF 8815, and other filter test 23369, MIL PRF 8815, and other filter test specifications in common use; are filter ratings filter ratings specifications in common use; are  They are intended to determine the They are intended to determine the relative ranking of relative ranking of  filters under arbitrary laboratory conditions under arbitrary laboratory conditions filters  These specifications do not relate filter performance These specifications do not relate filter performance  to fluid contamination levels in a dynamic operating to fluid contamination levels in a dynamic operating system system  MIL PRF 8815 doesn MIL PRF 8815 doesn’ ’t yield any useful information t yield any useful information  relating to the ability of the filter to control relating to the ability of the filter to control contamination in a dynamic operating system contamination in a dynamic operating system SSI SSI

Dynamic Filter Efficiency Dynamic Filter Efficiency (DFE) (DFE) A method of relating the total performance A method of relating the total performance of the filter to the contamination level in the of the filter to the contamination level in the fluid under dynamic operations: fluid under dynamic operations:  Capturing Efficiency Capturing Efficiency   Retention Efficiency Retention Efficiency  SSI SSI

What is DFE? What is DFE?  Variations in contamination levels are inherent Variations in contamination levels are inherent  to dynamic operating conditions prevailing to dynamic operating conditions prevailing during the duty cycle during the duty cycle  Variations in contamination can exceed safe Variations in contamination can exceed safe  levels during normal operations levels during normal operations  DFE is the test used to determine the maximum DFE is the test used to determine the maximum  contamination level a filter can control in a contamination level a filter can control in a dynamic operating system dynamic operating system SSI SSI

DFE Rating DFE Rating The DFE Rating of a filter defines its The DFE Rating of a filter defines its performance in terms of the fluid cleanliness it performance in terms of the fluid cleanliness it can maintain under dynamic operating conditions can maintain under dynamic operating conditions SSI SSI

00:01:33 100 10 20 30 40 50 60 70 80 90 0 00:05:48 00:10:03 00:14:21 00:18:39 00:22:55 00:27:13 00:31:31 00:35:47 00:40:03 00:44:21 00:48:39 0 50 100 150 200 250 Poly. (5 µ ) Poly. (4 µ ) dP 25 µ 20 µ 14 µ 10 µ 6 µ 5 µ 4 µ

Example, filtration Efficiency

Scientific Services, Inc Scientific Services, Inc Charlie Juhasz Charlie Juhasz SSI SSI Technical Director Technical Director Scientific Services Inc. Scientific Services Inc.

Economic Considerations Economic Considerations • Cost of operating with contamination Cost of operating with contamination • in the system in the system • Filter Effectiveness Filter Effectiveness • • Economic Benefits Economic Benefits •

Army Helicopter Hydraulic Fluid Samples (FY01) 70% 60.5% 60% 50% USN, USMC & USN, USMC & USCG ground USCG ground aircraft ≥ class 5. aircraft ≥ class 5. 40% % Samples 30% Class 3 considered Class 3 considered max acceptable max acceptable 18.1% 20% 10.5% 10% 6.5% 4.5% 0% 1 2 3 4 5+ NAVAIR Class ~ Increasing Contamination

Contaminated Contaminated Hydraulic Components Hydraulic Components CH-47D Integrated Lower Control Actuator (ILCA) Components