Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and aroud critical filtration/separation
most of mworking life ... and yet give just enough information that
each can take and arrive a result that is based on current or
state-of-the-art results.

ANY filter media (including compressed pubic hair) thats used in a
recirculation polishing system will work ... its all a matter of
degree. Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.
If doesnt matter if rust, bacteria or broken up toilet paper fibers
blocks the final filter to your engine... expecially during an
emergency. Unbonded cellulose is notorious for unloading particles or
allowing the particles to migrate through the filter .... OK if the
main system is not drawing fuel thats OK as the recirculating slurry
will probably be recaptured; but, if all hell breaks loose and you have
a high fuel demand at the time when the TP decides to unload itself or
its already trapped debris .... the whole system can catastrophically
fail ....

My objection to TP - very poor efficiency, migrates particles, migrates
fibers, unloads at increasing differential pressure, larger first cost
due to need for larger diameter housing, no constancy of retention,
knife edge seals of 'cartridge' - very limited in retention and VERY
prone to bypass. Short life due to low surface area. TP will '
deform' - wrinkle into a smaller mass when heavily laden and
differential pressure is high (remember those knife edge seals) then
unload and bypass.

As far as experience ..... the high tech/high purity industry used such
devices for many years: loose fiberglass, Kotex pads, string wound
cylinders, TP, chopped cellulose ....... until after WWII the world
started using captured German technology: membranes, cartridges, etc.
If TP were any good, industry would still be using it. The last such
system I personally replaced/upgraded was in the mid 70s. ..... as a
cost cutting measure!!!!!

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.


;-)

In article , Steven Shelikoff
wrote:

Rich,

I appreciate that you seem to be an expert on filtering theory even
though you also seem to lack the practical experience of actually using
the TP or PT depth filters we're talking about. I realize you don't
think they work. Even so, I'd love to hear your expert opinion
(absolutely no sarcasm intened) on why my Racor 2uM filter has lasted so
long (2 years now and still not clogged) after installing a TP prefilter
when I completely clogged two of the same filters in 20 minutes each
before installing the TP prefilter.

Steve

Rich,

What would you suggest in a stiuation where mechanical cleaning of
the tanks is not practical. In my case, the tanks are an integral part
of the hull. Inspection ports have been cut into the sides, but cannot
be opened without removing a couple of dozen bolts and slicing
through whatever they are bedded in. Then rebedding and bolting
them back in place. 3 ports in each tank probably corresponding to
baffled areas.

I don't think the tanks are in that bad of shape in terms of sediment.
In 4 years since we bought the boat we have bashed around the
Chesapeake, down the ICW, offshore for most of FL without
a problem. We started having problems after taking on fuel in
Palm Beach , then Man-O-War Cay, then Fernandina beach
on the way back north last spring. Its been problematic ever since.

Doug

"Rich Hampel" wrote in message
...
Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and aroud critical filtration/separation
most of mworking life ... and yet give just enough information that
each can take and arrive a result that is based on current or
state-of-the-art results.

ANY filter media (including compressed pubic hair) thats used in a
recirculation polishing system will work ... its all a matter of
degree. Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.
If doesnt matter if rust, bacteria or broken up toilet paper fibers
blocks the final filter to your engine... expecially during an
emergency. Unbonded cellulose is notorious for unloading particles or
allowing the particles to migrate through the filter .... OK if the
main system is not drawing fuel thats OK as the recirculating slurry
will probably be recaptured; but, if all hell breaks loose and you have
a high fuel demand at the time when the TP decides to unload itself or
its already trapped debris .... the whole system can catastrophically
fail ....

My objection to TP - very poor efficiency, migrates particles, migrates
fibers, unloads at increasing differential pressure, larger first cost
due to need for larger diameter housing, no constancy of retention,
knife edge seals of 'cartridge' - very limited in retention and VERY
prone to bypass. Short life due to low surface area. TP will '
deform' - wrinkle into a smaller mass when heavily laden and
differential pressure is high (remember those knife edge seals) then
unload and bypass.

As far as experience ..... the high tech/high purity industry used such
devices for many years: loose fiberglass, Kotex pads, string wound
cylinders, TP, chopped cellulose ....... until after WWII the world
started using captured German technology: membranes, cartridges, etc.
If TP were any good, industry would still be using it. The last such
system I personally replaced/upgraded was in the mid 70s. ..... as a
cost cutting measure!!!!!

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.


;-)

In article , Steven Shelikoff
wrote:

Rich,

I appreciate that you seem to be an expert on filtering theory even
though you also seem to lack the practical experience of actually using
the TP or PT depth filters we're talking about. I realize you don't
think they work. Even so, I'd love to hear your expert opinion
(absolutely no sarcasm intened) on why my Racor 2uM filter has lasted so
long (2 years now and still not clogged) after installing a TP prefilter
when I completely clogged two of the same filters in 20 minutes each
before installing the TP prefilter.

Steve

On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.

I considered it. And I realize that mechanically cleaning the tank and
entire fuel system on a regular basis would be the best solution. But
the polishing system I installed was much cheaper and solved the
problem. Even though it may be a band aid in your view in that the tank
walls are still dirty, that doesn't matter much to me as long as the
fuel going to the engine is clean. I'd probably be much more concerned
if I had a motorboat and depended entirely on the engine for motion.
But I have a sailboat and don't use the engine all that much. I only
burn maybe 30 gallons a year, and it's a 78 gallon tank.

Steve

And that is the rub. I have 2 96 gallon tanks on a sailboat.
I can't use fuel fast enough to keep the tanks out of trouble so a
polishing system seems to be the most practical.

Doug
s/v Callista

"Steven Shelikoff" wrote in message
...
On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.

I considered it. And I realize that mechanically cleaning the tank and
entire fuel system on a regular basis would be the best solution. But
the polishing system I installed was much cheaper and solved the
problem. Even though it may be a band aid in your view in that the tank
walls are still dirty, that doesn't matter much to me as long as the
fuel going to the engine is clean. I'd probably be much more concerned
if I had a motorboat and depended entirely on the engine for motion.
But I have a sailboat and don't use the engine all that much. I only
burn maybe 30 gallons a year, and it's a 78 gallon tank.

Steve

And that is the rub. I have 2 96 gallon tanks on a sailboat.
I can't use fuel fast enough to keep the tanks out of trouble so a
polishing system seems to be the most practical.

Doug
s/v Callista

"Steven Shelikoff" wrote in message
...
On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.

I considered it. And I realize that mechanically cleaning the tank and
entire fuel system on a regular basis would be the best solution. But
the polishing system I installed was much cheaper and solved the
problem. Even though it may be a band aid in your view in that the tank
walls are still dirty, that doesn't matter much to me as long as the
fuel going to the engine is clean. I'd probably be much more concerned
if I had a motorboat and depended entirely on the engine for motion.
But I have a sailboat and don't use the engine all that much. I only
burn maybe 30 gallons a year, and it's a 78 gallon tank.

Steve

Rich,

I'm looking through the McMaster-Carr catalog and am finding a bewildering
number of filter cartridges. None of them mention the term "depth
media" or such. Many come in regular and pleated versions. I did
find a nice SS housing with a T handle. It seems that a string-wound
polyester with 304 SS core is OK. I also see a Spun Polypropylene
media for $2.69 ea but the pleated version costs a whopping $30.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and aroud critical filtration/separation
most of mworking life ... and yet give just enough information that
each can take and arrive a result that is based on current or
state-of-the-art results.

ANY filter media (including compressed pubic hair) thats used in a
recirculation polishing system will work ... its all a matter of
degree. Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.
If doesnt matter if rust, bacteria or broken up toilet paper fibers
blocks the final filter to your engine... expecially during an
emergency. Unbonded cellulose is notorious for unloading particles or
allowing the particles to migrate through the filter .... OK if the
main system is not drawing fuel thats OK as the recirculating slurry
will probably be recaptured; but, if all hell breaks loose and you have
a high fuel demand at the time when the TP decides to unload itself or
its already trapped debris .... the whole system can catastrophically
fail ....

My objection to TP - very poor efficiency, migrates particles, migrates
fibers, unloads at increasing differential pressure, larger first cost
due to need for larger diameter housing, no constancy of retention,
knife edge seals of 'cartridge' - very limited in retention and VERY
prone to bypass. Short life due to low surface area. TP will '
deform' - wrinkle into a smaller mass when heavily laden and
differential pressure is high (remember those knife edge seals) then
unload and bypass.

As far as experience ..... the high tech/high purity industry used such
devices for many years: loose fiberglass, Kotex pads, string wound
cylinders, TP, chopped cellulose ....... until after WWII the world
started using captured German technology: membranes, cartridges, etc.
If TP were any good, industry would still be using it. The last such
system I personally replaced/upgraded was in the mid 70s. ..... as a
cost cutting measure!!!!!

DO NOT depend on filters to remove the crud in your system. If they
plug it means that you are contaminated and need to clean your fuel
system. Such plugging clearly indicates a **symptom**, the filters
prevented the symptom from becoming an extremis situation. If your
system is plugging filters, they did do their job as they are supposed
to .... but now go back in and clean the system! Resident particles
form and agglomerate into more particles. Bacterial scums feed other
bacteria, etc. Your symptoms of plugging filters means your system is
contaminated.... a filtration system is a band-aid or a 'condom' to
prevent stoppage. Consider to thoroughly mechanically CLEAN the tank.


;-)

In article , Steven Shelikoff
wrote:

Rich,

I appreciate that you seem to be an expert on filtering theory even
though you also seem to lack the practical experience of actually using
the TP or PT depth filters we're talking about. I realize you don't
think they work. Even so, I'd love to hear your expert opinion
(absolutely no sarcasm intened) on why my Racor 2uM filter has lasted so
long (2 years now and still not clogged) after installing a TP prefilter
when I completely clogged two of the same filters in 20 minutes each
before installing the TP prefilter.

Steve

On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and around critical filtration/separation
most of my working life ...

Sounds good to me...

/// Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.

Perhaps a test at home would be helpful.

Take a kitchen collender, A seive or funnel would also work well.
Place a sheet of kitchen roll in the aperture, pleated once to fit.
Spray the surface with Pam, olive oil, or soybean oil or any other oil
Momma has on hand. Make sure the paper is saturated.

Now pour water onto the surface.
Let me know how many particles break loose.
We'll compare notes if you like...
///
My objection to TP - very poor efficiency, migrates particles, migrates
fibers
\////
You either believe the folks who say that depth filters have saved
their fine surface filters from blocking, or you don't.
If you do believe that they are reporting honestly, then I imagine
you would say that at the operational level, that's the kind of
efficiency they prefer?

The home test may (or may not) demonstrate that an oil-soaked paper
tissue does not migrate particles or fibers.
I expect you will let us know if this is misconceived...

DO NOT depend on filters to remove the crud in your system.
////

Or in the version I prefer, referring only to the surface filters that
you use and prefer:
DO NOT depend on fine surface filters to remove crud in your system -
they will certainly block: fast.

Respectfully,

Brian Whatcott

Nope.... I suggest a test for you
Take 25-50 grams of the finest dust/crud you can find. Dump it in
upstream of a TP filter and see what happens ..... it will immediately
plug - or will hardly capture anything.

Change to a high surface area pleated filter dump in 25-50 grams of
crud, another 25-50 grams of crud, another 25-50 grams, then another
25-50 grams, then another .... then it will plug. Take out the
filter, examine .... you will find a small layer of crud on the
surface. That layer is called a "filter cake". That layer of debris
because the velocity throuth the 'cake' is so much smaller (than the
velocity through a TP etc. roll that it does in fact flow and until the
cake reaches a 'terminal' differential pressure will be the principal
means of particle captu dirt filtering out other dirt.
This cannot happen in a depth filter....because there is *no room for
the 'cake' to form* (inside the filter).

For a true depth filter, you add a filter aid (Diotomaceous earth,
perlite, etc.) on a continual basis so that the deposition is
controlled, the debris is contained in the cake of DE + crud. The
surface of the depth filter holds the cake. If the particles get
inside the depth filter it PLUGS. You can design a 'profiled' depth
filter that has a graded pore density.... bigger pores on the upstream
side, smaller pores on the downstream side ....and that costs about 20
times the price of a toilet paper roll ..... and also is a resin bonded
cellulose matrix. Resin bonded so that the cellulose matrix desnt
collapse upon itself during increasing differential pressure, doesnt
fall apart if it gets wet with water, etc.




In article , Brian Whatcott
wrote:

On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and around critical filtration/separation
most of my working life ...

Sounds good to me...

/// Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.

Perhaps a test at home would be helpful.

Take a kitchen collender, A seive or funnel would also work well.
Place a sheet of kitchen roll in the aperture, pleated once to fit.
Spray the surface with Pam, olive oil, or soybean oil or any other oil
Momma has on hand. Make sure the paper is saturated.

Now pour water onto the surface.
Let me know how many particles break loose.
We'll compare notes if you like...
///
My objection to TP - very poor efficiency, migrates particles, migrates
fibers
\////
You either believe the folks who say that depth filters have saved
their fine surface filters from blocking, or you don't.
If you do believe that they are reporting honestly, then I imagine
you would say that at the operational level, that's the kind of
efficiency they prefer?

The home test may (or may not) demonstrate that an oil-soaked paper
tissue does not migrate particles or fibers.
I expect you will let us know if this is misconceived...

DO NOT depend on filters to remove the crud in your system.
////

Or in the version I prefer, referring only to the surface filters that
you use and prefer:
DO NOT depend on fine surface filters to remove crud in your system -
they will certainly block: fast.

Respectfully,

Brian Whatcott

On Sun, 07 Dec 2003 06:24:24 GMT, Rich Hampel
wrote:

Nope.... I suggest a test for you
Take 25-50 grams of the finest dust/crud you can find. Dump it in
upstream of a TP filter and see what happens ..... it will immediately
plug - or will hardly capture anything.

I'm just wondering if you've actually tried this test or if it's just
based on your theory of the filters.

Steve

On Sun, 07 Dec 2003 06:24:24 GMT, Rich Hampel
wrote:

Nope.... I suggest a test for you
Take 25-50 grams of the finest dust/crud you can find. Dump it in
upstream of a TP filter and see what happens ..... it will immediately
plug - or will hardly capture anything.

OK; as far as I can tell, particulate fines *will* pass a depth filter
on the first pass. This makes your proposition completely true for one
clause of the either/or proposition.


Change to a high surface area pleated filter dump in 25-50 grams of
crud, another 25-50 grams of crud, another 25-50 grams, then another
25-50 grams, then another .... then it will plug.

OK: as far as I can tell, particulate fines will mostly pass a surface
filter rated for considerably larger particles, and block, for a
filter rated at considerably smaller particles. In the intermediate
range, as is well known, the retained particulate film provides
increasing resistance, and retention of decreasing particle sizes.

Take out the
filter, examine .... you will find a small layer of crud on the
surface. That layer is called a "filter cake". That layer of debris
because the velocity throuth the 'cake' is so much smaller (than the
velocity through a TP etc. roll

This was the only piece that left me uncomfortable. Supposing that
surface filters use lower velocity flow than depth filters in the
fuel polishing role is presuming a design choice that "don't
necessarily happen." Filter cakes are an artifact of surface
filters.

....that it does in fact flow and until the
cake reaches a 'terminal' differential pressure will be the principal
means of particle captu dirt filtering out other dirt.
This cannot happen in a depth filter....because there is *no room for
the 'cake' to form* (inside the filter).

For a true depth filter, you add a filter aid (Diotomaceous earth,
perlite, etc.) on a continual basis so that the deposition is
controlled, the debris is contained in the cake of DE + crud.

I am pleased that you are now referring to industrial uses of depth
filters: - like the one that brings you your tap-water, for instance,
or the depth filter that brings you your room-air.
But pre-loading a filter is not the fuel-polishing approach, so I
don't find it specially relevant,

The
surface of the depth filter holds the cake. If the particles get
inside the depth filter it PLUGS. You can design a 'profiled' depth
filter that has a graded pore density.... bigger pores on the upstream
side, smaller pores on the downstream side ....and that costs about 20
times the price of a toilet paper roll ..... and also is a resin bonded
cellulose matrix. Resin bonded so that the cellulose matrix desnt
collapse upon itself during increasing differential pressure, doesnt
fall apart if it gets wet with water, etc.

You again mention non resin cellulose filters falling apart when wet.
The home test I mentioned recently (I thought) would convince you
that these filter materials *don't get wet* in the intended
application?

Brian W




In article , Brian Whatcott
wrote:

On Fri, 05 Dec 2003 20:02:22 GMT, Rich Hampel
wrote:

Please appreciate that I dont want to appear to be an arrogant
know-it-all after being in on and around critical filtration/separation
most of my working life ...

Sounds good to me...

/// Whats wrong with TP, etc. is that the material used to filter
is not bonded, can digest (make more particles) in the presence of
water --- thus to do the exact opposite of what you are trying to do.

Perhaps a test at home would be helpful.

Take a kitchen collender, A seive or funnel would also work well.
Place a sheet of kitchen roll in the aperture, pleated once to fit.
Spray the surface with Pam, olive oil, or soybean oil or any other oil
Momma has on hand. Make sure the paper is saturated.

Now pour water onto the surface.
Let me know how many particles break loose.
We'll compare notes if you like...
///
My objection to TP - very poor efficiency, migrates particles, migrates
fibers
\////
You either believe the folks who say that depth filters have saved
their fine surface filters from blocking, or you don't.
If you do believe that they are reporting honestly, then I imagine
you would say that at the operational level, that's the kind of
efficiency they prefer?

The home test may (or may not) demonstrate that an oil-soaked paper
tissue does not migrate particles or fibers.
I expect you will let us know if this is misconceived...

DO NOT depend on filters to remove the crud in your system.
////

Or in the version I prefer, referring only to the surface filters that
you use and prefer:
DO NOT depend on fine surface filters to remove crud in your system -
they will certainly block: fast.

Respectfully,

Brian Whatcott