Fuel Polishing again.
 

On Fri, 09 Jan 2004 00:59:52 GMT, Brian Whatcott
wrote:

On Thu, 08 Jan 2004 05:54:34 GMT, (Steven
Shelikoff) wrote:

On Thu, 08 Jan 2004 02:51:46 GMT, Rich Hampel
wrote:

NOPE!
In pressure mode, the filter will also act as a 'coalescer' (bringing
similar surface tension fluids together to make larger and larger sized
particles) and such particles will settle out into a 'drop-out-pot'
..... or usually into the bottom of the filter bowl (bowl pointing
downwards). ///

All this begs the question, why does the filter media care whether it's
in "pressure" mode or "vacuum" mode? Sure, the plumbing and filter
cases care. But the media only sees a pressure differential across it.
What's the difference to the media if the there is 14psi (atmospheric
pressure) on one side and, say, 10 psi (a 4 psi vacuum drawing fuel
across the media) on the other side vs. 18 psi (4 psi pressure pushing
fuel across the media) on one side and 14 psi (atmospheric) on the
other?

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.

Steve


Looks like the contribution that mentioned a pressure pump's tendency
to mix and chop big water drops to a clogging emulsion where the
vacuum pump sucks them into the filter intact - that idea didn't
appeal to you?

Sure did. So does the idea that I'd rather have a malfunction that lets
air into the system than one that lets fuel out. But both of those
points leads to the conclusion that you should suck fuel through the
filter rather than push it through.

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode. Thus my
question, discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.

Steve

Fuel Polishing again.
 

Steven Shelikoff wrote:

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode.

I recommend sucking fuel through the primary separator
filters. The much finer secondary filters normally require
pressure feed to assure adequate flow through a reasonable
sized element. The canned type of filter is designed to work
under high pressure and are used very successfully and
safely in that mode by nearly every manufacturer of large
and small engines.

During many years of operating such filters in marine
applications the only time I have see one leak badly was
when the discharge from the filter was closed against the
positive displacement pump serving it. And in that case all
that happened was the rubber sealing ring blew out. Opening
the valve stopped the leak immediately.

... discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.

The element cannot possibly know what mechanism is used to
establish fluid flow through the filter. The only thing the
filter sees is rate of flow and as it clogs, differential.
Anyone who claims otherwise is ignoring some other factor or
talking BS.

It does not take much imagination to see that the same flow
and pressure can be applied to a filter housing by gravity,
a pump discharge or a pump suction.

Rick

Fuel Polishing again.
 

Steven Shelikoff wrote:

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode.

I recommend sucking fuel through the primary separator
filters. The much finer secondary filters normally require
pressure feed to assure adequate flow through a reasonable
sized element. The canned type of filter is designed to work
under high pressure and are used very successfully and
safely in that mode by nearly every manufacturer of large
and small engines.

During many years of operating such filters in marine
applications the only time I have see one leak badly was
when the discharge from the filter was closed against the
positive displacement pump serving it. And in that case all
that happened was the rubber sealing ring blew out. Opening
the valve stopped the leak immediately.

... discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.

The element cannot possibly know what mechanism is used to
establish fluid flow through the filter. The only thing the
filter sees is rate of flow and as it clogs, differential.
Anyone who claims otherwise is ignoring some other factor or
talking BS.

It does not take much imagination to see that the same flow
and pressure can be applied to a filter housing by gravity,
a pump discharge or a pump suction.

Rick

Fuel Polishing again.
 

The smaller the retention size of the filter, and so arranged for
drainage so as not to collect free water inside the filter (core) will
coalesce the emulsion and effect separation into free water and cleaned
oil .... just need a proper sump volume at the bottom of the filter
bowl. The mathematical enhancement of repeated passes (tank turnovers)
through a recirculating filter will more than adequately take care of
'emulsions'.


The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous. Centrifuges are extreme high maintenance rotating and
power consuming equipment and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion. Do you also use a nephalometer to
arrive at when the centrifugation is complete?
As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine. Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.



In article k.net,
Rick wrote:

Steven Shelikoff wrote:

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.

The difference is that if the pump suction pulls water and
fuel directly from the tank it will do an excellent job of
mixing it up to form an emulsion that will not filter out
very effectively.

The path should be, a basket strainer to catch the chunks, a
separarator/filter to eliminate the bulk of the water and
the smaller suspended particles, the pump, then the finer
stages of filtration.

This is all assuming you don't have access to a centrifuge
which is really the best way to handle the process.

Rick

Fuel Polishing again.
 

The smaller the retention size of the filter, and so arranged for
drainage so as not to collect free water inside the filter (core) will
coalesce the emulsion and effect separation into free water and cleaned
oil .... just need a proper sump volume at the bottom of the filter
bowl. The mathematical enhancement of repeated passes (tank turnovers)
through a recirculating filter will more than adequately take care of
'emulsions'.


The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous. Centrifuges are extreme high maintenance rotating and
power consuming equipment and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion. Do you also use a nephalometer to
arrive at when the centrifugation is complete?
As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine. Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.



In article k.net,
Rick wrote:

Steven Shelikoff wrote:

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.

The difference is that if the pump suction pulls water and
fuel directly from the tank it will do an excellent job of
mixing it up to form an emulsion that will not filter out
very effectively.

The path should be, a basket strainer to catch the chunks, a
separarator/filter to eliminate the bulk of the water and
the smaller suspended particles, the pump, then the finer
stages of filtration.

This is all assuming you don't have access to a centrifuge
which is really the best way to handle the process.

Rick

Fuel Polishing again.
 

Its the way that the deposition of debris in a filter behaves, if you
build the 'cake' inside the filter media the life of the filter becomes
very short in comparison to 'cake' formation on or 'immediately inside'
the surface.
There is a valid doctoral discertation awating the person who solves
this dilemma ... so far no one can fully explain it, and the filtration
industry will stand pat on pressure filtration vs. vacuum filtration
.... all based on actual performance data.



In article , Steven Shelikoff
wrote:

On Fri, 09 Jan 2004 00:59:52 GMT, Brian Whatcott
wrote:

On Thu, 08 Jan 2004 05:54:34 GMT, (Steven
Shelikoff) wrote:

On Thu, 08 Jan 2004 02:51:46 GMT, Rich Hampel
wrote:

NOPE!
In pressure mode, the filter will also act as a 'coalescer' (bringing
similar surface tension fluids together to make larger and larger sized
particles) and such particles will settle out into a 'drop-out-pot'
..... or usually into the bottom of the filter bowl (bowl pointing
downwards). ///

All this begs the question, why does the filter media care whether it's
in "pressure" mode or "vacuum" mode? Sure, the plumbing and filter
cases care. But the media only sees a pressure differential across it.
What's the difference to the media if the there is 14psi (atmospheric
pressure) on one side and, say, 10 psi (a 4 psi vacuum drawing fuel
across the media) on the other side vs. 18 psi (4 psi pressure pushing
fuel across the media) on one side and 14 psi (atmospheric) on the
other?

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.

Steve


Looks like the contribution that mentioned a pressure pump's tendency
to mix and chop big water drops to a clogging emulsion where the
vacuum pump sucks them into the filter intact - that idea didn't
appeal to you?

Sure did. So does the idea that I'd rather have a malfunction that lets
air into the system than one that lets fuel out. But both of those
points leads to the conclusion that you should suck fuel through the
filter rather than push it through.

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode. Thus my
question, discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.

Steve

Fuel Polishing again.
 

Its the way that the deposition of debris in a filter behaves, if you
build the 'cake' inside the filter media the life of the filter becomes
very short in comparison to 'cake' formation on or 'immediately inside'
the surface.
There is a valid doctoral discertation awating the person who solves
this dilemma ... so far no one can fully explain it, and the filtration
industry will stand pat on pressure filtration vs. vacuum filtration
.... all based on actual performance data.



In article , Steven Shelikoff
wrote:

On Fri, 09 Jan 2004 00:59:52 GMT, Brian Whatcott
wrote:

On Thu, 08 Jan 2004 05:54:34 GMT, (Steven
Shelikoff) wrote:

On Thu, 08 Jan 2004 02:51:46 GMT, Rich Hampel
wrote:

NOPE!
In pressure mode, the filter will also act as a 'coalescer' (bringing
similar surface tension fluids together to make larger and larger sized
particles) and such particles will settle out into a 'drop-out-pot'
..... or usually into the bottom of the filter bowl (bowl pointing
downwards). ///

All this begs the question, why does the filter media care whether it's
in "pressure" mode or "vacuum" mode? Sure, the plumbing and filter
cases care. But the media only sees a pressure differential across it.
What's the difference to the media if the there is 14psi (atmospheric
pressure) on one side and, say, 10 psi (a 4 psi vacuum drawing fuel
across the media) on the other side vs. 18 psi (4 psi pressure pushing
fuel across the media) on one side and 14 psi (atmospheric) on the
other?

IOW, even if the pump is past the filter drawing fuel through it, the
filter is still in "pressure" mode because it's really the atmospheric
pressure pushing fuel through the filter.

Steve


Looks like the contribution that mentioned a pressure pump's tendency
to mix and chop big water drops to a clogging emulsion where the
vacuum pump sucks them into the filter intact - that idea didn't
appeal to you?

Sure did. So does the idea that I'd rather have a malfunction that lets
air into the system than one that lets fuel out. But both of those
points leads to the conclusion that you should suck fuel through the
filter rather than push it through.

However, Rich recommends that fuel be pushed through due to some
tendency of the filter media to work better in that mode. Thus my
question, discounting all other aspects at hand such as the pump
emulsifying the fuel before it gets to the filter, why does the filter
media care which side the pump is on? Fuel is being pushed through it
either way, either by the pump with a higher pressure on the inlet or
the atmosphere with a higher pressure on the inlet.

Steve

Fuel Polishing again.
 

Rich Hampel wrote:

The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous.

your opinion is not universal. Besides, we were writing
about FUEL POLISHING ... an activity normally performed
alongside a dock at rather extended intervals.

Centrifuges are extreme high maintenance rotating and
power consuming equipment

Just because you don't like them ... and you have a peculiar
vision of "extreme" maintenance.

and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion.

A rather extremist position. There are plenty of boats under
75 feet that use a centrifuge to handle fuel separation
tasks. Why do you think Alfa Laval build one the size of a
gallon milk jug? Your personal view and experience does not
define the marine industry in the 21st century.

Do you also use a nephalometer to
arrive at when the centrifugation is complete?

Once through will do.

As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine.

Water does not increase the cetane number ... do you know
what that means anyway?

Water serves to reduce the temperature of combustion and
thereby reduce the formation of oxides of nitrogen in a diesel.

Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.

Got that one wrong too. There are several techniques
available in large diesels that layer the fuel and water
injected, and another that injects water first then fuel.

Let's stick to filtration and fuel polishing. If you want to
have a snit go chat with K over on rec. boats.

Rick

Fuel Polishing again.
 

Rich Hampel wrote:

The use of a centrifuge on the small volume boat tankage .... borders
on ludicrous.

your opinion is not universal. Besides, we were writing
about FUEL POLISHING ... an activity normally performed
alongside a dock at rather extended intervals.

Centrifuges are extreme high maintenance rotating and
power consuming equipment

Just because you don't like them ... and you have a peculiar
vision of "extreme" maintenance.

and do NOT effect total removal/separation of
emulsions. If you have enough power to run a centrifuge, then I
suggest that you rip out the fossil fuel engine and simply replace with
an electric motor for propulsion.

A rather extremist position. There are plenty of boats under
75 feet that use a centrifuge to handle fuel separation
tasks. Why do you think Alfa Laval build one the size of a
gallon milk jug? Your personal view and experience does not
define the marine industry in the 21st century.

Do you also use a nephalometer to
arrive at when the centrifugation is complete?

Once through will do.

As an aside .... a water emulsion will enhance the combustion
efficiency by increase of the apparent cetane number of the fuel, or
the octane number in a gasoline engine.

Water does not increase the cetane number ... do you know
what that means anyway?

Water serves to reduce the temperature of combustion and
thereby reduce the formation of oxides of nitrogen in a diesel.

Its the FREE water thats the
'problem' as simply 'slugs' of free water simply do not burn.

Got that one wrong too. There are several techniques
available in large diesels that layer the fuel and water
injected, and another that injects water first then fuel.

Let's stick to filtration and fuel polishing. If you want to
have a snit go chat with K over on rec. boats.

Rick

Fuel Polishing again.
 

Rich Hampel wrote:

There is a valid doctoral discertation awating the person who solves
this dilemma ...

It is not a dilemma that keeps many boaters awake at night,
trust me.

Rick