Engine exhaust system with sequential loading of multiple filters
AssigneeDonaldson Company, Inc.
InventorsMarty A. Barris, Wayne M. Wagner
Life of this patent
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Abstract
In a diesel engine exhaust system a plurality of valved ceramic filters are connected in parallel in the exhaust stream and loaded sequentially. While one filter is preferentially loaded, a second filter is opened to the exhaust stream when backpressure reaches a predetermined value. The secondary filter is removed from the exhaust stream when air flow to the engine drops a discrete amount below a peak air flow determined by the backpressure which would cause the secondary filter to be placed in the exhaust stream. The preferentially loaded filter is bypassed when completely loaded and regenerated. The secondary filter is then preferentially loaded and the sequence continues.
Claims9
A method of selecting among multiple filters for placement in an exhaust stream of an engine for loading with particulates and for removal from said stream for regeneration, comprising the steps of:
- placing a first filter in said stream;
- sensing backpressure in said stream between said filter and said engine;
- placing a second filter in said stream when said backpressure is greater than a first predetermined value;
- sensing air flow to said engine;
- removing said second filter from said stream when said air flow is less than a second predetermined value.
Apparatus for reducing particulates from exhaust gases of an engine, comprising:
- an exhaust line in fluid communication with said engine to receive the exhaust gases from said engine;
- a plurality of exhaust filtration assemblies connected in parallel with one another with each being in fluid communication with said exhaust line, each of said assemblies including a filter and a valve, said valve being between said engine and said filter;
- means for regenerating said filters;
- means for controlling said regenerating means and said valves to preferentially load a first of said filters and use another of said filters to alleviate backpressure during higher flow conditions until said first is loaded and then preferentially load a second of said filters while alleviating backpressure during higher flow conditions with yet a third of said filters until said second filter is loaded and to continue sequentially loading said filters, said controlling means operating said valves to bypass said filters when loaded and operating said regenerating means to regenerate said filters when loaded and bypassed.
Dependencies are inferred from the claim text.