www.klatchroasting.com: USBC champion, voted 2009 'best micro-roaster'

Flojet and rotary pump questions

Postby AndyS on Fri Jul 01, 2005 1:03 am

(split from Fiorenzato Briccoletta - A Pro's Perspective by moderator...)

malachi wrote:First thoughts are that I seem to be getting more of the "clarity" from the espresso made with this machine that with other home machines. It's still not quite as defined as what I would get off a Mistral or the like, but it's less fuzzy. I'm thinking it is probably the result of the rotary pump in this case


A few thoughts:
1. Would you mind briefly explaining how the Flojet pump system works? I've never used one of them. My reason for asking is, of course, if the inlet pressure to the rotary pump varies, the outlet pressure will vary by the same amount. I'm just wondering if pressure control is poorer with this setup as compared to a typical plumbed in commercial machine.
2. Even if pressure control is poorer than in a commercial setup, it may still be better than in many vibe machines (which is probably the point you were making above).
3. Aside from pressure variation and pressure control, another variable is the time it takes for pressure to rampup at the beginning of the extraction. Depending on the way the rotary is setup, this could be one second or many seconds. Vibe pump rampups are usually 5-10 seconds.

Apologies again if I'm restating obvious stuff.
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company
User avatar
AndyS
 
Posts: 1059
Joined: May 05, 2005
Location: NY
Quotable Quote
"It's interesting that there's no agreement even on the simple things." --Jim Schulman. "Some folks like espresso that tastes like the coffee brewed, or like the coffee intensified, or like the coffee smells. Everyone has their own goal/hope/framework." --Chris Tacy, Best technique for finding best flavor


Postby terryz on Fri Jul 01, 2005 10:08 pm

I can respond with regards to the Flojet.

The Flojet pump that we used in this installation is a on demand bottled water pump. When pressure drops below 20 PSI the pump kicks in and builds pressure back up to 40 PSI. The change is small and is instant rather than a slow ramp up. The effect at the machine is nominal.

The difference between this type of system and that of a machine connected directly to the water mains, is that a mains connection deals in a higher PSI fluctuation. Spikes and drops in pressure can be as high as 50 PSI on a municipal system.

The Flojet rotary pump system is far better in any case to a vibration pump drawing water from a tank.

Thank you for your question Mr. Schecter :D I will now return you to your regular reviewer.
Terry Z
Espressoparts.com
____________________________________
Much of espresso speculation is faith based.- Michael Teahan 2011
terryz
 
Posts: 151
Joined: May 03, 2005
Location: Olympia, WA

Postby AndyS on Fri Jul 01, 2005 11:07 pm

terryz wrote:The Flojet pump that we used in this installation is a on demand bottled water pump. When pressure drops below 20 PSI the pump kicks in and builds pressure back up to 40 PSI. The change is small and is instant rather than a slow ramp up. The effect at the machine is nominal.


I must not be understanding you. You appear to be saying that the inlet pressure to the rotary will vary 20 PSI (1.4 BAR). Therefore, the extraction pressure (pump outlet pressure) will vary 1.4 BAR. This is "nominal???"

terryz wrote:The difference between this type of system and that of a machine connected directly to the water mains, is that a mains connection deals in a higher PSI fluctuation. Spikes and drops in pressure can be as high as 50 PSI on a municipal system.


20 PSI is a lot less than 50 PSI, but neither is acceptable. Some people (not just Schomer) say that 0.1 bar makes a discernible impact on the shot. After reading Schomer's book, I've always assumed that high-end shops took his advice and properly controlled their inlet pressure.

Naive assumption?

Does the machine require mains pressure in order to fill the boiler? Otherwise, why would there be an advantage to this inlet system?

terryz wrote:The Flojet rotary pump system is far better in any case to a vibration pump drawing water from a tank.


In what sense?
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company
User avatar
AndyS
 
Posts: 1059
Joined: May 05, 2005
Location: NY

Postby malachi on Sat Jul 02, 2005 12:06 pm

I suppose I could put a static tank in my system if I really thought that the pump created line pressure was the limiting factor with the espresso.
"Taste is the only morality." -- John Ruskin
malachi
 
Posts: 2544
Joined: May 05, 2005
Location: sfca

Postby AndyS on Sat Jul 02, 2005 1:49 pm

malachi wrote:I suppose I could put a static tank in my system if I really thought that the pump created line pressure was the limiting factor with the espresso.


I doubt it's the "limiting" factor, but I know you consider it "a" factor, because you're one of the guys that specifies very precise brew pressures with certain coffees.
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company
User avatar
AndyS
 
Posts: 1059
Joined: May 05, 2005
Location: NY

Postby terryz on Sat Jul 02, 2005 2:21 pm

AndyS wrote:
terryz"]The Flojet pump that we used in this installation is a on demand bottled water pump. When pressure drops below 20 PSI the pump kicks in and builds pressure back up to 40 PSI. The change is small and is instant rather than a slow ramp up. The effect at the machine is nominal.


I must not be understanding you. You appear to be saying that the inlet pressure to the rotary will vary 20 PSI (1.4 BAR). Therefore, the extraction pressure (pump outlet pressure) will vary 1.4 BAR. This is "nominal???"

[quote="terryz wrote:The difference between this type of system and that of a machine connected directly to the water mains, is that a mains connection deals in a higher PSI fluctuation. Spikes and drops in pressure can be as high as 50 PSI on a municipal system.


20 PSI is a lot less than 50 PSI, but neither is acceptable. Some people (not just Schomer) say that 0.1 bar makes a discernible impact on the shot. After reading Schomer's book, I've always assumed that high-end shops took his advice and properly controlled their inlet pressure.

Naive assumption?

Does the machine require mains pressure in order to fill the boiler? Otherwise, why would there be an advantage to this inlet system?

terryz wrote:The Flojet rotary pump system is far better in any case to a vibration pump drawing water from a tank.


In what sense?[/quote]

Mr. Schecter :D

Look I spent an hour with this machine and during that time I became convinced.....Oh never mind. :shock:

Ok so I agree with you that it is a huge difference in pressure. However we are simulating a "Typical" Installation in a home enviroment.

This particular installation also includes a carbon block filter from Everpure, which oddly enough holds back pressure drop, and acts as a very small static tank due to the volume of water it is holding. In this instance it hold double the volume used in filling the boiler.

The rotary pump in this machine is what is used to fill the boiler rather than line pressure. As you know this is typical of this level of machine.

In a more custom application the use of an accumulator would be installed and recommended to control the loss of pressure. In a commercial application a static tank or an extrol accumulator would be used.

I'm off to experiment with the garden hose pressure in the backyard. Happy independance day.
Terry Z
Espressoparts.com
____________________________________
Much of espresso speculation is faith based.- Michael Teahan 2011
terryz
 
Posts: 151
Joined: May 03, 2005
Location: Olympia, WA

Postby AndyS on Sat Jul 02, 2005 3:14 pm

Hi Terry!

Enjoying this discussion. You know that I love you, man, right? In the platonic sense, of course. :-)

terryz wrote:Look I spent an hour with this machine and during that time I became convinced.....Oh never mind. :shock:


C'mon! Speak! Convinced of what?

terryz wrote:This particular installation also includes a carbon block filter from Everpure, which oddly enough holds back pressure drop, and acts as a very small static tank due to the volume of water it is holding. In this instance it hold double the volume used in filling the boiler.


Interesting, even though "holds back pressure drop" is a very weird expression.

terryz wrote:The rotary pump in this machine is what is used to fill the boiler rather than line pressure. As you know this is typical of this level of machine.

In a more custom application the use of an accumulator would be installed and recommended to control the loss of pressure. In a commercial application a static tank or an extrol accumulator would be used.


From what you described so far I don't see why the Flojet's in there at all. My home procon has been happily sucking out of a bottle for 4 years, and I don't have to worry about inlet pressure variation. Tell me why, Obi-wan Kenobi.

terryz wrote:I'm off to experiment with the garden hose pressure in the backyard. Happy independance day.


Best to you! And remember, four beers and fireworks don't mix! :-)
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company
User avatar
AndyS
 
Posts: 1059
Joined: May 05, 2005
Location: NY

Postby malachi on Sat Jul 02, 2005 6:02 pm

The Procon in this case is not the full size commercial one, but rather an itty-bitty one (smallest I've ever seen).

It's entirely possible that it would work just fine without the FloJet, but I'd rather not destroy a review machine finding out.

If I were going to buy a Briccoletta or the like and have it as my one and only home machine I would without a doubt plumb it in, and would probably also install a static tank as well.
"Taste is the only morality." -- John Ruskin
malachi
 
Posts: 2544
Joined: May 05, 2005
Location: sfca

Postby AndyS on Sat Jul 02, 2005 11:33 pm

malachi wrote:The Procon in this case is not the full size commercial one, but rather an itty-bitty one (smallest I've ever seen).

It's entirely possible that it would work just fine without the FloJet, but I'd rather not destroy a review machine finding out.



Yeah, destroying review machines is a bummer, especially before big holiday weekends! :-)

Is the pump one of the MagDrive Series 2/3 pumps?

If so, Procon clearly states that they're good for the usual six foot suction lift.
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company
User avatar
AndyS
 
Posts: 1059
Joined: May 05, 2005
Location: NY

Postby HB on Sat Jul 02, 2005 11:53 pm

AndyS wrote:If so, Procon clearly states that they're good for the usual six foot suction lift.

Another data point... The Elektra A3 has a Procon pump, but the owner's manual and a big warning on the machine itself say it must have minimum positive pressure of 1.5 bar to operate properly (max. 4 bar). Probably has to do with its preinfusion.
Dan Kehn
User avatar
HB
 
Posts: 14508
Joined: Apr 29, 2005
Location: Cary, NC