Motor vehicles, apart from a few specialized variants, have filters to remove particulates and contaminants from the intake air. This greatly increases engine service life.

Such filters are either disposable paper cartridges, or the oil-bath type.

In dusty environments, frequent filter maintenance is vital to prevent loss of power and possible damage.

However, a saving could be made if a water-bath prefilter were installed.

The water-bath filter would physically closely resemble the oil-bath filter. Since it uses water, daily cleaning is cheap and simple - just rinse out the mud - and there are no environmental issues regarding disposal of the filtrate - just dump it on the ground, because that's where it came from in the frst place.

The downside is that the prefilter will entrain moisture into the intake air. However, since the outside air is likely to be very dry anyway (hence the dust), the additional moisture should not be a problem, and anyway most of it will be trapped by the succeeding oil bath filter, whose maintenance intervals can be correspondingly lengthened as the particulate burden will be much lower.

The increased intake resistance can be simply compensated by tweaking the forced induction system.
-- 8th of 7, Jul 15 2017

//just dump it on the ground, because that's where it came from in the frst place.// But shirley the same applies to oil?

And a quick Google tells me that oil-bath filters (and hence, one presumes, water-bath filters) aren't nearly as effective as paper filters.

Also, I would imagine that blowing several litres per second over a water bath will lead to rapid evaporation of said water, especially as the pressure will be slightly below ambient. And if you let the filter run dry, all the accumulated crud will just dry up and launch itself back into the intake.
-- MaxwellBuchanan, Jul 15 2017


// aren't nearly as effective as paper filters. //

Opinions vary.

// several litres per second over a water bath will lead to rapid evaporation //

Through. The air blows through the bath.

// if you let the filter run dry, //

... the BorgCo system* will replenish the level from a holding tank, using condensate recovered from the air conditioning system.

*Patent applied for.
-- 8th of 7, Jul 15 2017


// Opinions vary. //

That is always the case. There is always a correct opinion, and then various other opinions which, by definition, vary.

//The air blows through the bath. // So, not like an oil bath filter, then? I am given to understand that, in an oil bath filter, the airstream impinges on the surface of the oil, such that contaminant particles impact the oil and are trapped, whilst the air is deflected and proceeds on its way.

In fact, according to the Wikipedia, "This U-turn takes the air at high velocity across the surface of the oil pool.". That information is to be found on the page entitled "Air Filter" under the sub-heading "Oil bath".

It is also perhaps notable, to some extent, that the next sub-heading in the same article is entitled "Water bath", and describes an innovation not completely unlike your present invention.
-- MaxwellBuchanan, Jul 15 2017


The innovation is using the water bath as a prefilter for the oil bath.

The water bath is admittedly less efficient, as stated; but a water prefilter and an oil main filter is more efficient than either one on its own, and is cheaper overall, once the extra capital cost is written off.
-- 8th of 7, Jul 15 2017


Ah. Well, I suspect the patent lawyers would argue that this is a "straightforward combination of elements, each performing the same function when in combination as when used independently", so I don't hold out soul-enhancing hope for your "patent applied for". But you never know.

Would I be correct in assuming, from the degree of fervour behind this invention, that you have just been forced to shell out between £29.99 and £49.99 for a new air filter for your Trabant? If so, please take my advice: the secret of becoming rich is to spend more. This is due to a corollary to the well-known law that expenditure increases to match income. People who try to economize merely embark on a downward spiral that ends up with them travelling on buses.
-- MaxwellBuchanan, Jul 15 2017



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