Adsorbent structures for removal of water and fuel contaminants in engine oil

Abstract

Devices and methods for removal of condensed, blow-by contaminants with small molecular dimensions from the circulating lubricating engine oil of internal combustion engines, including automotive engines, with a positive crankcase ventilation system are disclosed. These condensable blow-by contaminants include water, alcohols and hydrocarbons with preponderantly seven or fewer carbon atoms. A macroporous structure comprising alumino-silicate particles with micro-pores is at least partially immersed in the circulating oil. The micro-pores are sized to adsorb the small, condensed, blow-by, contaminant molecules but not the larger oil molecules. The particles may be multi-layered, with an inner layer adapted for adsorption of polar molecules. Adsorption is most extensive at lower oil temperatures and decreases as the oil temperature increases. Thus at low temperatures the contaminant molecules may be adsorbed, removed from the oil and temporarily stored in the micropores. At high temperatures some of the contaminants will desorb and be re-incorporated in the oil. The desorbed contaminants will be carried with the higher temperature oil into the engine crankcase where they may vaporize and be removed by the engine positive crankcase ventilation system.

Description

TECHNICAL FIELD[0001]This invention pertains to devices and methods for temporarily adsorbing water and fuel contaminants from lubricating oil circulated in automotive internal combustion engines. More specifically, this invention pertains to the use of suitably-located crystalline particulate materials to adsorb such contaminants from relatively cold engine oil to extend oil life and to minimize potential corrosive damage to engine components. The contaminants are later released from the oil, for removal from the engine, when the engine is operating and the oil is relatively hot.BACKGROUND OF THE INVENTION[0002]Diesel, gasoline, and alcohol fueled internal combustion engines find broad application in both motor vehicles and stationary applications like motor-generators.[0003]Many such engines use hydrocarbon-based, oil lubricating systems in which the oil is pumped during engine operation from an underlying reservoir, up and over the pistons, cylinder walls, inlet and exhaust valve...

AI Technical Summary

Benefits of technology

The patent text describes a method for removing contaminants from engine oil by using micro-porous crystalline solids, such as zeolites, which can adsorb molecules of relatively small size. These contaminants can cause damage to the engine and reduce oil life. The zeolites are placed in the oil circulation path or the oil reservoir and adsorb the contaminants as they circulate through the engine. The zeolites then desorb the contaminants at higher temperatures and the contaminants are removed by the engine's positive crankcase ventilation system. The use of zeolites in this way helps to minimize the deleterious effects of the contaminants and improve engine performance.

Problems solved by technology

At lower engine oil temperatures some of these contaminants may condense and remain in the engine lubricating oil and contribute to reduced oil life and engine damage.

As the oil temperature increases, adsorption of the contaminants becomes less favorable and some of the contaminants may be desorbed to again be incorporated in the oil.

With continued increase in oil temperature, yet further contaminant desorption will occur, the vapor pressure of the contaminants will increase and contaminant gasses and vapors will accumulate in the crankcase where they may be permanently removed by the PCV system.

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