On Sun, 9 Dec 2007 06:33:45 -0800 (PST), RichH
wrote:

OK Brian, ........... lets not get carried away.....

by depth filtration I dont mean toilet paper and kitchen towel
rolls.
Such cellulose in 'those' items are designed to fall apart after long
soak in water ....
The cellulose fibers are not 'resinated' and thus bound together; if
the fibers can 'move' under increasing pressure such 'filters' will
unload the debris back into the system.
Assuming that the pressures are kept low enough to keep these 'items'
from unloading they are not a 'graded poer density' ... meaning that
the average pore size is uniform throughout the matrix .... by depth
filtration I mean a statistical graded pore density filter media in
which the statistical 'pore' size gets smaller and smaller as you get
deeper into the filter matrix.
Further the toilet paper and kitchen towel filters are sealed with a
'knife edge' which is simply not a very good means to 'seal' a filter
under about 40µM .... the knife edge sealing methods simply 'bypass'
liquid, especially as the supposed filter material under increasing
pressure 'moves'.
Although the cost of toilet paper and kitchen towel filters is small,
the housing $$$$ are immense in comparison to 'efficient' filtration
thus the initial first cost is much much higher - false economy.
Toilet Paper and Kitchen Towels do not have the 'fibers' fixed in
place by resin binders .... and the fibers that can be 'released' can
be as much in weight as what you intend to capture ..... ever hear of
papier mache?
Kotex pads stuffed into an empty filter housing would be vastly better
than toilet paper and kitchen towels.

So, when I speak of 'depth filtration' I mean a fairly accurate graded
pore density filter media ... an example of such would be as used for
the filter-press filtration of BEER and other beverages used to
remove a high % of solids; filtration that is specifically engineered
to remove 'snots and gels' and 'deformables' etc. as well as 'hard'
particles, fibers bound together by a resin, graded pore density,
filter-aids (perlite and diatomaceous earth) incorporated into the
'matrix' ... sometimes even 'specific' starches
(hydroxymethylcellulose, etc. added) to remove emulsified water,
etc. DEPTH FILTRATION, not 'ass-wipers' contained in ****-poor
made 'cheap and dirty' housings. g


I am familiar with depth filtering as used in filter presses for
filtering water out of electric transformer oil years ago. Is this
similar to what you are describing and is so can you offer some
information regarding make and model (understanding that you are not
indorsing any maker) as I haven't knowingly ever seen a filter of this
type on a small diesel, say anything under about 500 HP.

I think the majority (not all) of the posters here are sailboat guys
where 50 H.P would be a big engine.

Disclaimer: I'm seeking information not controversy =:-)


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)