If your polishing system is 'off line' ... not a part of the normal fuel
distribution and return loop the following will exponentially improve
the retention ability and 'speed of recovery' if you happen to get a
load a cruddy fuel or the sea state breaks a slug of particale loose
from the tank walls, etc.:

Dont use 2uM filters in the loop! .... increase the nominal retention
rating to 10 or 15uM and the resultant final particle distribution *in
the tank* will be essentially zero and accomplish this level FASTER. ...
here's why:
Fibrous media filters have retention capability at essentially ALL
particle size levels. A 15uM fuel filter will remove approx 85 to 95% of
of 15uM particles in a one single pass of the fluid through it, at 10uM
50%, at 5uM perhaps 30%, at 2uM maybe 15%. A 15uM filter will have
approx 4 to 5 times the flow rate capacity (gallons per minute per psid)
of a 2uM filter ... meaning that the 15uM filter will cause less work
for the pump and overall flow will be FASTER. A 2uM filter will deposit
2uM particles primarily on the surface of the media, a larger retention
media will capture 2uM particles down deep in the media (for *more*
capacity of small particles) Since a polishing system is a closed
recirculation system you are constantly filtering the same fluid over
and over and over, each time the fluid passes through the filter it
leaves a few percent of smaller particles behind in the filter, since a
larger retention filter has better flow characteristics the pump will
push through MORE fluid per minute and have less amperage draw. When
using a 2uM filter, the fluid returned during recirculation to the tank
is again mixed with particle/debris laden fluid. A larger retention
filter will do the same job, to the same level of particles in the tank
..... and do it faster because the larger retention filter has less
resistance to flow. With less resistance to flow a larger retention
filter will have less probability of extruding and releasing
SOFT/DEFORMABLE particles at it approaches differential pressures that
would 'clog' a filter.
Another benefit - If for example you have a crud contamination hanging
on the walls of the tank and the sea state causes the attached
particles/crud to break free and enter the fluid, the larger retention
filter (because of its less resistance to flow) will recover the tank
back to an acceptable particle distribution (particle recovery) FASTER
than a smaller retention filter. Same story when taking onboard a load
of fuel that is contaminated.

Recirculation filtration is exponentially faster, more efficient, and
vastly more cost effective than single pass filtration. Use the largest
filter retention possible (~10-20uM) to effect the fastest tank
turn-over... the tank will after a few turn-overs be to the same level
of residence particles. For the mathematicians, what is happening is an
exponential decay of resident particles *in the tank*; since the larger
retention filter (even with less efficiency with respect to the 'target
retention') is Faster because the exponential decay 'in the tank' is
faster. If you have time to burn, take ANY filter (includes compressed
pubic hair), recirculate for looooong times and you will have
essentially ZERO particles in the tank. Typically in industry a recirc.
filter is sized about 5 to 10 times the size of the target residual
retention.


hope this helps.




Roy G. Biv wrote:
jscanlon wrote in message

no bs at all...

my permanently installed independent polishing system draws about 5
gallons (100 gallon tank) every 6.5 minutes through a racor 1000 with
2 micron (can switch to racor 900 when 1000's vacuum increases)

the engine has a racor 500 with 10 micron , then racor 500 with 2
micron, then the perkins 4-108 engine mounted filter.
as rich points out the 1000 elements aren't much more expensive than
the 500 elements, don't let the 500/1000 designations throw you, the
surface area of the 1000 is MUCH greater than twice the surface area
of the 500......

RichH wrote in message ...
Get the type (filter head casting) with the integral hand operated
priming pump (plunger); or, see below.

How do the new units work? I'm imagining a procedure similar to an oil
filter replacement, except that after I remove the old, I have to fill the new
one with fuel.

Install a 12v fuel pump between the tank and the first filter. Energize
the pump with a switch.
When installing new filters, etc. turn on the pump and then sequentially
bleed all the filters, lift pump, final filter. Also serves as a
'back-up' lift pump. When not energized the integral valves in the pump
will allow the fuel delivery system to operate just as before.

Actually lift pumps on engines shouldn't be located where they are, they
should be at the tank. Then you have a positive pressure system that
cant suck air from leaky joints, etc. Additionally a positive pressure
system will vastly increase the service life of the filters!


The only bad side to the positive pressure is if you have a leak. I
was on a large boat once that had a leak by the injection pump. The
boat was running fine, but I make it a habit to take a look at the
engines every so many hours. So I go down for a peek, find about 3 to
4 inches of diesel in the bilge. The dangerous part, some of the fuel
was in the form of a fine mist, not a good thing, thank God for water
cooled turbo's. My point is, I think I'd rather live with the problem
of finding an air leak.

Thanks Rich,

I've been doing filter validation for 20 years, so yes, I know of what
you speak. Now, show me either of:

A spun depth filter with "a 0.000000000002 micrometer" absolute
porosity,
OR

ANY spun filter with any absolute porosity rating.

The point is, you were wildly exaggerating, and I was pointing that out.
If you *could* create a filter of the listed porosity, the surface
tension alone would create such a high pressure you'd never get any flow
at all. As you obviously know.

Oh, and you might want to reconsider statements about "differential
pressure is SOLEY due to the absolute viscosity" of the liquid. Never
had the fun of filtering thixotropic products eh?

Keith Hughes


RichH wrote:

ummmmmmm yourself

Bubble point is related to retention efficiency ---- ONLY.

If your were filtering a 60/40 mixture of isopropyl alcohol and water
your statement would have (some) validity .... but ONLY if your were
using uniform porosity polymeric *membranes* at retention levels below
0,45uM. It is a mathematical/physical impossibility to consider 'bubble
point' for such fixed media (fiberous) and comparatively HUGE retention
sizes. If you know what a bubble pointg is, then you also know that such
fixed fibrous media has inconsistant porosity and permeability - ie. a
2uM media will have 'pores' approaching 50 or 100uM!!! Bubble point is
simply not applicable.
For yourself I respectfully suggest that you look up the filtration
regimes as defined by the ASTM "OSU F-1 protocols"

Operating differential pressure is SOLEY due to the absolute viscosity
of the fluid!!!!

Bubble point is a nondestructive CORELATION or a bacterial (specified
test organism) challenge (or latex spheres) ... to a plugging situation
using specific test organisms on MEMBRAWES. Oil filters use a fiberous
media ... where bubble point is totally nonapplicable: 1. non uniform
media, 2. retention matrix larger than 1uM. Tell me where on this
planet that one can do a 'bubble point' (or forward flow diffusion) on
the media type used in fuel oil filters? - is fiberous and non-uniform
in permeability; and thus, are unable to be tested via bubble point as
the contact wetting angle of surface tension vs. the media is
nonuniform. Bubble point is ONLY perfomed on MEMBRANES of ?0.45uM used
in filtration .... not on fiberous nonuniform porosity media.

Differential pressue of a CLEAN filter is SOLELY due to the absolute
viscosity (viscous shear) of the fluid being filtered. Surface tension
is irrelevent with respect to viscous shear/?P. Changing the surface
tension (wetting angles) will ONLY affect the *retention* ability under
varying intrusion pressures ... ie:. modifying the van der walls
absorbtive attraction at the BET surface of the media or membrane.
Differential pressure affects the internal velocity of the fluid THROUGH
filter media/membrane AND those media with high ?P will have/approach
insufficient contact or residence time for absorbtion mechanism of
capture; thus, leaving only mechanical means of 'captu'seiving',
direct interception and inertial impaction. You can matematically
predict by the (area1/area2)E1.66 = (velocity2/velocity1)E1.66 =
((Q/deltaP1)/(Q/deltaP2))E1.66 ...as a LIFE performance predictor (the
exponential varies between 1 for high viscosity non-newtonian fludis to
approx 1.666 for newtonian fluids.... no surface tension/wetting angles
involved.

Thanks for those insights Rich, I guess the key is how much the
different uM ratings load the pump and change its volume/time. I have
used different micron rated filters and never noticed a perceptible
change in the flow rate (5 gallons in 6.5 minute is pretty slow)...






RichH wrote in message news:...
If your polishing system is 'off line' ... not a part of the normal fuel
distribution and return loop the following will exponentially improve
the retention ability and 'speed of recovery' if you happen to get a
load a cruddy fuel or the sea state breaks a slug of particale loose
from the tank walls, etc.:

Dont use 2uM filters in the loop! .... increase the nominal retention
rating to 10 or 15uM and the resultant final particle distribution *in
the tank* will be essentially zero and accomplish this level FASTER. ...
here's why:
Fibrous media filters have retention capability at essentially ALL
particle size levels. A 15uM fuel filter will remove approx 85 to 95% of
of 15uM particles in a one single pass of the fluid through it, at 10uM
50%, at 5uM perhaps 30%, at 2uM maybe 15%. A 15uM filter will have
approx 4 to 5 times the flow rate capacity (gallons per minute per psid)
of a 2uM filter ... meaning that the 15uM filter will cause less work
for the pump and overall flow will be FASTER. A 2uM filter will deposit
2uM particles primarily on the surface of the media, a larger retention
media will capture 2uM particles down deep in the media (for *more*
capacity of small particles) Since a polishing system is a closed
recirculation system you are constantly filtering the same fluid over
and over and over, each time the fluid passes through the filter it
leaves a few percent of smaller particles behind in the filter, since a
larger retention filter has better flow characteristics the pump will
push through MORE fluid per minute and have less amperage draw. When
using a 2uM filter, the fluid returned during recirculation to the tank
is again mixed with particle/debris laden fluid. A larger retention
filter will do the same job, to the same level of particles in the tank
.... and do it faster because the larger retention filter has less
resistance to flow. With less resistance to flow a larger retention
filter will have less probability of extruding and releasing
SOFT/DEFORMABLE particles at it approaches differential pressures that
would 'clog' a filter.
Another benefit - If for example you have a crud contamination hanging
on the walls of the tank and the sea state causes the attached
particles/crud to break free and enter the fluid, the larger retention
filter (because of its less resistance to flow) will recover the tank
back to an acceptable particle distribution (particle recovery) FASTER
than a smaller retention filter. Same story when taking onboard a load
of fuel that is contaminated.

Recirculation filtration is exponentially faster, more efficient, and
vastly more cost effective than single pass filtration. Use the largest
filter retention possible (~10-20uM) to effect the fastest tank
turn-over... the tank will after a few turn-overs be to the same level
of residence particles. For the mathematicians, what is happening is an
exponential decay of resident particles *in the tank*; since the larger
retention filter (even with less efficiency with respect to the 'target
retention') is Faster because the exponential decay 'in the tank' is
faster. If you have time to burn, take ANY filter (includes compressed
pubic hair), recirculate for looooong times and you will have
essentially ZERO particles in the tank. Typically in industry a recirc.
filter is sized about 5 to 10 times the size of the target residual
retention.


hope this helps.




Roy G. Biv wrote:
jscanlon wrote in message

no bs at all...

my permanently installed independent polishing system draws about 5
gallons (100 gallon tank) every 6.5 minutes through a racor 1000 with
2 micron (can switch to racor 900 when 1000's vacuum increases)

the engine has a racor 500 with 10 micron , then racor 500 with 2
micron, then the perkins 4-108 engine mounted filter.
as rich points out the 1000 elements aren't much more expensive than
the 500 elements, don't let the 500/1000 designations throw you, the
surface area of the 1000 is MUCH greater than twice the surface area
of the 500......

You're welcome, but this is not a place to show off that one can
properly open the correct box of filters.

Lets get back to helping simple boating folks to keep the crud and
critters out of their fuel and diesel engines in the simplest and most
efficient, less costly way possible, please.

As applied to simple plain vanilla fuel oil systems .... Ill stand pat
and depend on 35+ years of experience in engineering, design, tech
support, marketing, consulting, in high tech filtration and separation
technology, ... with the 'major' players and with the up-and-comers (&
some down and goners).

For the last time ..................

Now, show me either of:

A spun depth filter with "a 0.000000000002 micrometer" absolute
porosity,
OR
cant fathom hyperbole, and simplified exaggeration to attempt to explain
to the non-technical.


ANY spun filter with any absolute porosity rating.
Pall Profile, Osmonics Selex, are a few of the more common examples ....
last time I looked these were absolute to a beta 5000 efficiency which
would equate to a approx 1X10E7 / sq. cm. titre reduction (LRV) for "up
to" but not quite sterilizing requirements. Ya gotta remember before
macro-foam polymer membranes the industry used such things as potassium
titanate fibers, asbestos, etc. to effect single pass 'absolute' level
filtration.


The point is, you were wildly exaggerating,
No, I was being "mister wizard" to the Saturday morning science class.


If you *could* create a filter of the listed porosity, the surface
tension alone would create such a high pressure you'd never get any flow
at all. As you obviously know.
News to me, you must have had a 'public school education' ;-) ...
1. absolute visosity is the prime factor of viscous shear hence
differential pressure ... Ill stand on that statement, unless they've
recently changed physical chemistry, chemical engineering, and the laws
of fluid dynamics.


Never
had the fun of filtering thixotropic products eh?
Biological gels or protenaceous concentrations? .... about once every
3-4 months but with tangential filtration levels in the nanometer or
10000 Dalton range. I actually prefer viscoelastics.

If you want to take this offline, my professional fees are $175/hr.

Roy G. Biv wrote:
Thanks for those insights Rich, I guess the key is how much the
different uM ratings load the pump and change its volume/time. I have
used different micron rated filters and never noticed a perceptible
change in the flow rate (5 gallons in 6.5 minute is pretty slow)...


There is a 'ratings game' with such filters. Firstly, 'paper' filter
media cant be made that accurately, plus the cellulose fibers used are
relatively thick in comparison to the 'pores'. So, in especially the
larger retention ratings you probably wont see much difference in flow
performance. With respect to cheap filters, you usually get what you pay
for.

:-)