MANN+HUMMEL Introduces New Oil Separation Technology

DETROIT, Feb. 28 -- New technology to improve oil separation in closed crankcase ventilation systems required to meet stringent new emission requirements will be introduced by MANN+HUMMEL at the 2003 SAE World Congress in Detroit.

MANN+HUMMEL's new oil-separation technology uses centrifugal force to separate harmful contaminants and emissions from a vehicle's engine oil. The new designs are more efficient and durable than previous systems.

Closed crankcase ventilation is mandated by European and future U.S. emission standards to keep engine pollutants from escaping into the atmosphere through a vehicle's crankcase.

At SAE, MANN+HUMMEL will show a new parallel-cyclone system that features an especially compact design. In addition, the company will unveil a new centrifuge system that provides a high-quality alternative to fleece, labyrinth or cyclone oil-separation systems.

Dr. Pius Trautmann, who heads the company's process development group for air filter elements and crankcase ventilation systems, notes that the newly developed parallel-cyclone and centrifuge systems are both designed to meet current and future oil-separation and emission requirements for crankcase ventilation.

"Our parallel-cyclone design is especially suited for applications where space is at a premium," Trautmann notes. "This new system provides a high- quality alternative to the labyrinth oil-separation systems used in the past."

Blow-by gases and other contaminants are able to escape into the engine crankcase from an engine's combustion chamber through gaps between the pistons and cylinder walls. Closed crankcase ventilation systems prevent these gases from being released into the atmosphere by filtering or separating out oil droplets and returning the cleansed gases to the engine's air-intake system.

MANN+HUMMEL engineers have developed a system that utilizes parallel cyclones to achieve even better results than today's typical systems that use labyrinth, impact-separator and single-cyclone devices. The new system achieves separation efficiencies of 70 to 80 percent. The company's new centrifuge system has an even higher efficiency rating of more than 95 percent, similar to the degree of separation achieved by the company's high- quality fleece separators. Fleece, however, must be replaced at regular service intervals.

Technical Background:

Cyclones are centrifugal separators through which contaminated blow-by gas is passed. The measure of a cyclone's separation efficiency is "separation drop size" or the minimum size of a droplet of oil that can be separated from blow-by gas. Separation drop size in turn depends on the pressure drop within the separator itself. Since the pressure drop in an individual oil separator is limited, MANN+HUMMEL developed a series of smaller cyclones operating in parallel to improve overall system efficiency. For example, tests have shown that six cyclones operating in parallel can reduce the separation drop size by up to 40 percent, compared to a single cyclone.

MANN+HUMMEL's new centrifuge systems incorporate a disk separator and chamber centrifuge. The design uses centrifugal force to separate gas and contaminants from engine oil. In general, as faster rotation is achieved, the oil is more efficiently separated from blow-by gas in the crankcase. MANN+HUMMEL's disk-stack centrifugal separators represent a high-quality alternative to both fleece and cyclone systems.

About MANN+HUMMEL

The MANN+HUMMEL Group is an international company. In 2002, the company achieved sales of approximately $1.1 billion. The MANN+HUMMEL Group currently employs around 9,500 people at 41 locations worldwide. The company develops, produces and sells technically complex automotive components such as air filter systems, intake manifold systems, liquid filter systems and cabin filters for the automotive industry, and filter elements for vehicle servicing and repair. For general engineering, process engineering and industrial manufacturing sectors the company's product range includes industrial filters, filter systems, and materials handling systems and equipment. MANN+HUMMEL's customers come from a large number of sectors, with OEM supply for the automotive industry occupying a key position. Further information about MANN+HUMMEL can be found under http://www.mann-hummel.com/ .