Nurri Leva S. A. - Page 17

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Primacog

#161: Post by Primacog »

jontyc wrote:I see a drop from 130°C → 128°C when steaming for one on the Izzo 5L, manometer dropping 0.15 bar (1.75 to 1.60). Interesting you're seeing 0.5 bar drop as steam tables indeed predict a 0.15 bar drop.

Main thing though is whether steaming milk for two can be sustained without the turbulence dying - I'm sure that will be the case after seeing the Sync's 2 L crawl through 12 oz milk, but simply changing the tip made it kick.
To be exact im seeing 0.3 to 0.4 bar drops over 10 seconds, not 0.5 bar. However the temp drop is similar which is about 2 degrees. Would the fact that the izzo has a 5 litre boiler va the 1.8 litre one on the nurri make that difference? (The izzo also must have had a pretty powerful element in the boiler because mine required a 220v 15A circuit.
LMWDP #729

Marcje

#162: Post by Marcje »

Perhaps it could be Pressostat (Izzo) vs PID control (Nurri) related?
When I changed the temperature control of the boiler in my Strega from a Pressostat to a PID, I had the impression that the system was a bit less responsive (ie, the temperature would drop more while steaming).
My theory was that:
1) A pressostat can quickly sense a dropping pressure, and switch on the heater. A PID however, is using a temperature probe as input to apply power to the heater. If the temperature probe is in the boiler water, you may get a delayed response, as the water cools down a bit slower than the steam pressure drops. I recently put the probe above the boiler water (so in the steam), and my feeling that this already works a bit better.
2) In addition, the pressostat is on/off and will switch on the heater with 100% power, whereas a PID will send less power to the heater if the difference between the setpoint and actual temperature is small

I know this is all my perception, so perhaps I should be doing a 20 second steaming test to see how far the temperature drops with a Pressostat vs a PID...

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Viernes

#163: Post by Viernes »

uncola wrote:is this the first Nurri espresso machine? I have to say, as a prospective buyer, all these running changes and fixes are pretty discouraging. I guess if it's his first it's a little more understandable
I would like to clarify something. Lately, part of the conversation about the machine has turned out into "machine issues".

There's some misunderstanding here. The announcement of the PID software update, was made to give good news to users who asked for independent PID control for each of the 3 elements (2 boilers + group). This was heard and Nurri staff contacted Gicar to ask for software development.

The upcoming PID SW is a software update to provide new features. Not a patch to fix something broken. If the current PID SW had a problem, then a patch could be released to fix the bug, but there's nothing to fix, and you don't release a patch as a whole SW update with new functionalities to do this.

About the steaming issue, there has been no change. Also, we must take into account that the L-Type steam boiler it's only 1.8L with 1000W. It's not realistic to expect infinite steaming power. For a more sustained steam, it will necessary to change the steam tip. I think the current configuration gives a nice balance. You can froth a medium size pitcher quickly, and also a little pitcher without painting the ceiling. The boiler capacity saves you some cash and that's one of the reasons why the machine is ready in under 12 minutes.

coffeeOnTheBrain

#164: Post by coffeeOnTheBrain »

The pressure drop is influenced by a couple of factors.

The heat capacity is directly related to the volume. The heat capacity is the main indicator of the initial pressure drop after opening the steam wand.
The initial drop is also the influenced by the volume of the steam wand and pipes that need to be filled.

A PID reacts on a temperature/pressure change instantly, but only a PID with well tuned parameters will react quick. That said a PID can be tuned to use the full power of the heater easily because overshooting basically doesn't matter for a steam boiler of a non HX machine.

On the other hand a pressostat only reacts when the pressure drops below the lower threshold.

Ideally the heater can heat quicker than the machine looses pressure. The loss of pressure is defined by the size of the hole(s) of the steam wand.
If the heater and the steam hole are matched like that the pid can be setup in a way that you don't lose pressure at all after slight initial drop.

cyclezib

#165: Post by cyclezib »

I really don't understand this concern with steaming. Let me vent (pun intended)?
The machine does a fantastic job of steaming a pitcher of milk suitable for a couple of Cappuccinos.
I've yet to read anyone say that they are failing to steam their milk in fast enough time, nor getting it to proper temperature.

My take on the comments is that they are all hypothetical concerns with thermodynamics and have nothing to do with what is happening in the home.

Lastly, the focus on steaming aside, how about discussing the excellent taste of espresso this machine yields?

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Viernes

#166: Post by Viernes »

cyclezib wrote:I really don't understand this concern with steaming. Let me vent (pun intended)?
The machine does a fantastic job of steaming a pitcher of milk suitable for a couple of Cappuccinos.
I've yet to read anyone say that they are failing to steam their milk in fast enough time, nor getting it to proper temperature.
Yes, Exactly. The machine gives big steam as we can see in the EspressoTV video. Flow is high and fast but controlled enough for little pitchers too. And the microfoam is very good.

Cuprajake

#167: Post by Cuprajake »

How do you do the update

I had a crem profiler that had a usb dongle

Starspawn2318

#168: Post by Starspawn2318 »

The double spring produces up to 11bar pressure? What do you think of the profile it gives you compared to other machines that maybe max at 9 bar?

Primacog

#169: Post by Primacog »

cyclezib wrote:I really don't understand this concern with steaming. Let me vent (pun intended)?
The machine does a fantastic job of steaming a pitcher of milk suitable for a couple of Cappuccinos.
I've yet to read anyone say that they are failing to steam their milk in fast enough time, nor getting it to proper temperature.

My take on the comments is that they are all hypothetical concerns with thermodynamics and have nothing to do with what is happening in the home.

Lastly, the focus on steaming aside, how about discussing the excellent taste of espresso this machine yields?
I fully agree. In fact i did five bursts of steaming one after another with only one or 2 minutes gap between them and rhe jets of steam were all equally powerful. I cannot imagine a situation for home use or even for a party or social gathering when the machine's steaming capacity would be tapped out.

It is also very easy to achieve great qualolity texture with the milk. I think bakafish made a good point aboit the design of rhe steam wand being instrumental in this respect.

I also agree that the quality of the shots are absolutely exceptional and for me clearly they surpass the izzo.
LMWDP #729

bakafish

#170: Post by bakafish »

 
Although the steam pressure drops quickly, I don't have any problem steaming milk. Steaming 200ml milk can be completed in 10 seconds and the quality (mouth feel) is even better than it from my Lelit Bianca V1 which has almost infinite steaming power.
 
Marcje wrote:Perhaps it could be Pressostat (Izzo) vs PID control (Nurri) related?
When I changed the temperature control of the boiler in my Strega from a Pressostat to a PID, I had the impression that the system was a bit less responsive (ie, the temperature would drop more while steaming).
My theory was that:
1) A pressostat can quickly sense a dropping pressure, and switch on the heater. A PID however, is using a temperature probe as input to apply power to the heater. If the temperature probe is in the boiler water, you may get a delayed response, as the water cools down a bit slower than the steam pressure drops. I recently put the probe above the boiler water (so in the steam), and my feeling that this already works a bit better.
2) In addition, the pressostat is on/off and will switch on the heater with 100% power, whereas a PID will send less power to the heater if the difference between the setpoint and actual temperature is small
The first could be wrong. The water cools down and the PID responds quickly. Instead, the pressurestat has a range. For example, if you use a pressurestat which range is 1.2 bar to 1.5 bar, when the boiler reaches 1.5 bar, it stops heating the boiler and wait for the boiler cooling to 1.2 bar to start heating again. If you steam milk during heating, the heating element will keep working with full power, but if you steam milk during cooling, the heating element will not work until the pressure drops to the lower limit of the range of the pressurestat.

A good PID should have the parameter called "proportional range", like below in the Lelit Bianca's PID manual. But I did not see this paratemer in my Nurri Leva.


Lelit Bianca has dual PID, so it has different parameters for both boilers. Bc is used on the coffee boiler and the Bs is used on the steam boiler, so it can give full power to the heating element of the steam boiler immediately when you use steam. The 220V Lelit Bianca V1 has a 1.5L steam boiler with a 1400W heating element.

I had contact Antonio about the PID firmware update. He said they are almost ready to update the firmware of the L-Type. It will involve only the independent option to change PID parameters for each probe.

At first I think a PID can have only one set of parameters, but I could be wrong according to Antonio. Let's see how it goes.

cyclezib wrote: Lastly, the focus on steaming aside, how about discussing the excellent taste of espresso this machine yields?
Really good. Fantastic. Much better than my Lelit Bianca V1. Although some people prefer single spring, I have to say that the peak pressure can be controlled if you know enough for the lever machine. I don't mean to hold the lever during extraction. It's too tired. The peak pressure is determined by the spring length (the lever angle) when your hand leaves the lever, and the spring length is determined by the water volumn in the grouphead. If you release the lever when the puck is not full pre-infusion, some water in the grouphead will be absorbed by the puck, so the water volumn and peak pressure drops. Double springs acutally give me much more to play with. Unless you prefer low pressure and hign volumn espresso.