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Warming up Silvia

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  • Thundergod
    replied
    Re: Warming up Silvia

    Its all about process Jim.
    Follow it properly and you dont have a problem.

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  • jggall01
    replied
    Re: Warming up Silvia

    Originally posted by Thundergod link=1199143138/15#15 date=1200562036
    Timer.
    Almost all of the sad stories I read online about dead Silvias seem to start with: "I forgot to turn the [insert the name of your favorite switch here] off and then the timer came on in the morning. When I looked at the machine, it was [overheated, dead, dry, on fire, etc.]."



    Jim

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  • jggall01
    replied
    Re: Warming up Silvia

    Originally posted by Greg Pullman link=1199143138/0#14 date=1200551078
    ... what it tells me is that via the steam + flush method its possible to get the group up to the right temperature in about 10 minutes compared to about 35 with the standard method.
    Greg -

    I cant support this opinion with data, but I think that the 84C group temperature (after 10 minutes) will be enough below the eventual 90C temperature to have an effect on shot temperature.

    My suggestion would be to bump up the setpoint a couple of degrees when you dont have time for a full warmup. This would probably compensate for the slightly cooler group.

    As always, though, adjust to taste ;-)

    Jim

    PS - when you need to hear some more well-deserved praise, let me know, and Ill tell the story again about how much I like the tampers I received last month.

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  • gregpullman
    replied
    Re: Warming up Silvia

    Thats if you know what time youll be home!

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  • Thundergod
    replied
    Re: Warming up Silvia

    Timer.

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  • gregpullman
    replied
    Re: Warming up Silvia

    Very interesting, thanks for your (obviously and understandably exhausted!) efforts. I guess there are lots of interpretations, but what it tells me is that via the steam + flush method its possible to get the group up to the right temperature in about 10 minutes compared to about 35 with the standard method. I think Ill still use the regular warm-up period when time allows, but for a quick coffee soon after arriving home the flush method may be just whats required.

    Thanks!
    Greg

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  • jggall01
    replied
    Re: Warming up Silvia

    Originally posted by Greg Pullman link=1199143138/0#10 date=1200089308
    Very interested to see the results...
    One last test to see the effects of Gregs warmup scheme. I turned the machine on from a cold start, then immediately turned on the steam switch. I let the steam run through 4 PID-controlled cycles.

    Then, at around the 8-minute mark, I turned off the steam switch and flushed water (mostly steam at first) through the group. Once the temperature had dropped below the PID setpoint of 109C, I stopped the flush and let the PID take over.

    Compared to the 3 other warmup methods, this one had the greatest short term effect on the group temperature. During the flush, the group temperature exceeded 100C. But as soon as the flush was done, the temperature dropped fairly quickly back down to 84C before slowly starting to rise again.

    The eventual temperature of the group, regardless how the warmup is done, is around 90C. This method did not really decrease the time it takes to get all the way to 90C - this is still around 50 minutes.

    But it did get the group up to a more usable (if not optimum) temperature much quicker than the other methods we tried here.

    Im not sure I can draw any conclusions as far as what you should do to warm up your machine. But if you take a look at this final graph, maybe it will give a better idea of whats going on with the machine under the 4 different scenarios.

    Experiment over.

    Jim



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  • gregpullman
    replied
    Re: Warming up Silvia

    Hence the value of this sorta forum, I didnt even know that was there, nice find! Id be interested to see what effect the earlier steam circuit activation has though. What Im suggesting is having the boiler full of water and at steam temp then running the brew system as normal, except itll be superheated water that comes out not just brewing water. Boiler would end up as full as it would after a normal brew cycle.

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  • Sammus
    replied
    Re: Warming up Silvia

    I cant believe noone has brought up this article: http://www.coffeekid.com/archived/rancilio/cheatsilvia, even though these instructions are for a on PID silvia, Im sure they can be roughly adapted with similar results...I guess thats basically what these last two posts have done :

    On another note, if you juts run steam through the group wont there be some issue with the boiler not being full? I used to do something like what your talking about, except I would open the steam wand and hit the brew switch, which resulted in steam blasting from both the group and the steam wand, until I had a steady stream of water from the wand. I think this basically ensures the boiler is full... not sure of the effect this had on heating up times, but it would have to help.

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  • gregpullman
    replied
    Re: Warming up Silvia

    Yep that sounds about right Jim. Flushing through the group is the critical part of the process as it gets the hot water / steam right into the group to warm it up quickly rather than relying purely on thermal conduction from the boiler. With the PF in place, I normally flush this into the cups to be used to help pre-heat them quickly too, and if theyre tall cups they normally contain all the spitty water.

    Very interested to see the results...

    Greg

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  • jggall01
    replied
    Re: Warming up Silvia

    Originally posted by Greg Pullman link=1199143138/0#8 date=1199968029
    Another trick I use in conjunction with the above is to run warming flushes. I.e. turn the machine on and turn the steam switch on straight away, let it sit there for say 5 minutes at steam temp, then flush say 100ml or whatever of water...er, steam through the group, then leave it a bit longer to all equalize. But Ive not really stuck to any particular timings on this. How effective is this at speeding up the warm-up process, and what sort of timings / flushes are required to get an even, stable temperature?
    Heres what Im thinking for another test:

    1. Turn on machine, immediately turn on steam switch
    2. Run for 4 heater cycles at steam setpoint (this should be around 5 minutes)
    3. Turn off steam switch
    4. Run water through group until boiler temp drops below PID setpoint. I usually do this using the steam wand, so Im not sure how blasting the steam through the group will go
    5. Let PID take control at brew setpoint, and see what happens with the group temp

    Is that sorta what you had in mind?

    Jim

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  • gregpullman
    replied
    Re: Warming up Silvia

    Yes I do have one Jim. I was going to measure this myself but since you have all the stuff I may as well let the expert do it!

    Another trick I use in conjunction with the above is to run warming flushes. I.e. turn the machine on and turn the steam switch on straight away, let it sit there for say 5 minutes at steam temp, then flush say 100ml or whatever of water...er, steam through the group, then leave it a bit longer to all equalize. But Ive not really stuck to any particular timings on this. How effective is this at speeding up the warm-up process, and what sort of timings / flushes are required to get an even, stable temperature? (Sorry, this is probably going to be a laborious exercise!)

    By the way the SD3Cs working a treat! So much less messing around than before. Thanks! [smiley=tekst-toppie.gif]

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  • jggall01
    replied
    Re: Warming up Silvia

    One final variation to look at: in the 3rd trial, I turned the steam switch on immediately and let the light go through a sequence of on/off/on/off before turning off the steam switch.

    The graph shows this makes almost no difference from argons original procedure (except maybe shortening the "tending to the machine" time when first turning it on).

    Needs to be noted that this machine has both brew and steam temps under PID control, so results will be different for a machine with either brew-only PID control, or no PID control.

    All for now unless there are questions.

    Jim



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  • argon
    replied
    Re: Warming up Silvia

    Hi Jim

    fantastic work - thanks for that

    cheers

    argon

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  • jggall01
    replied
    Re: Warming up Silvia

    Certainly, ensuring a full boiler is very important when you do this.

    While I was doing final on-machine testing for a couple of kits for CSers (thanks!), I gathered some data.

    First, I duplicated argons procedure: switched the machine on from a cold start, let it come to setpoint of 109C, then turned on the steam switch. Once the steam reached 150C, I turned off the steam switch and left the machine alone until it cooled back down to the original setpoint of 109C. This occurred at around the 16 minute mark, BTW.

    Next, after an overnight rest, I started the machine from cold again. But this time I just let it idle for around 50 minutes, as is my normal practice.

    I have a grouphead sensor (thanks Eric S) in my bench Silvia. My criteria for a "warmed up machine" is when the group temperature has stopped rising and is stable. On this machine, in my cold shop (19C-20C normally), the warmed-up group runs at 90C.

    Here are the significant results:

    Trial 1 (using steam switch):
    grouphead temp after 16 min = 80.7C
    grouphead temp after 35 min = 88.7C

    Trial 2 (no steam switch):
    grouphead temp after 16 min = 74.7C
    grouphead temp after 35 min = 87.5C

    So, I think the bottom line is that the steam switch trick is a big help. The group will be around 6C hotter using argons method than it would be with a simple 16 minute warmup.

    But it will still not be completely to a stable situation. I cant say if the difference in espresso taste would be noticeable using this 16 minute steam-enhanced warmup vs a full 50 minute idling warmup, but it looks like the group might still be around 1.5C short of "fully warmed up."

    Probably leaving the steam switch on for an extra minute or so would bring it all the way up. I will see if I can persuade the elves to take a few minutes to run an additional test (they have been quite grumpy here after the big Christmas rush on kits).

    Below (I hope) is a graph of the data:




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