skyryders90 wrote:
Hmm ... care to share some more details and perhaps some photos?

I will post as soon as I take some photos this week.

remember; the brewtus is a dual boiler setup, so I use the system to control a circ pump in the thermosyphon loop to bring the group up to a temp much closer to the boiler temp. when I need to drop a degree or two I use the cooling loop of the control to reverse flow on the thermosyphon to drop group temp using the relatively cooler water from the bottom of the boiler. there is not a lot of capacity to really "cool" the group but to drop a degree is not a big issue. the "cooling" feature is more to give me a bit more agility with adjustments and was never intended as anything other than "I could do it ...so why not".


Sean

terryz wrote:There is an even better solution by way of a device we will be installing on Malachi's Bricoletta (Soon to be referred to as the Bric House!)

It's a cool idea that we have yet to try on a small boiler HX machine but on commercial machines in testing proved to be a reasonable solution to HX lock up.........

More on that in a couple of weeks.

Aloha,

How much longer?

There is just so much fun in resurrecting an old post - especially when it talks about a group temperature sensor mounted using a Swagelok fitting

Some alternative solutions would be:

Install the Faema E-61 Legend thermosyphon control valve (p/n 2211-135 817-SX OR 2211-135 816-DX) for about $127. Unfortunately, some disassembly, re-soldering, and adapting is required.

Install a Swagelok brass needle valve (properly chosen) for about $30 to control the thermosyphon flow.

Install a fixed orifice teflon disk as Jon did with his Expobar - Installing thermosyphon restrictor on expobar office pulser

Something tells me that the days of the cooling flush are slowly drawing to a close.

hello my name is jon.

Install a fixed orifice teflon disk as Jon did with his Expobar

i have a fixed orifice teflon disc in the thermosyphon in my expobar pulser. i really like it, however without erics TC adapter i would be not so happy. i think it is a vital piece of the puzzle for brewing espresso.

Something tells me that the days of the cooling flush are slowly drawing to a close.

i think the cooling flush is here to stay for me, until brewtus. ahhh someday.

i like the idea of being able to reduce the water to a specific temp. i wish i started flushing at 208° instead of 215°. eric showed me that the temp at the TC adapter is about 4° hotter than at the group. i guess i cold turn down the p-stat but we all know that story, i like to steam milk. i found a good spot with minimal flushes but maximum steam power.

i can choose a temp to brew at and flush to a specific temp on erics tc and usually can get what i want. it like adjusting the temp on the fly, its fun to experiment and see what temp each coffee tastes best at. or i can mess with my wife and make her a really hot or really cold shot and see if she notices, sometimes its an eww thats terrible or sometimes the opposite.

things have really smoothed out for me once i put the restrictor in there. an adjustable one (manual or PID/electronic) would be cool but i think it would be over engineered and simplicity sometimes wins.

dont forget to get yourself an official Eric S thermocouple TC adapter.

fun times. lets have some coffee.

jon

erics wrote:Something tells me that the days of the cooling flush are slowly drawing to a close.

I know, i am drawing up an old post...

What do you mean? Even if you slow the thermosyphon down to a standstill and get the grouphead temp to "perfect" you would still need to cool the thermosyphon loop water with a cooling flush.

No, you wouldn't. It is absolutely possible to adjust the pstat of certain machines such that one can simply walk up to the machine and pull a shot as evidenced by the below graph of a Vibiemme Domobar Super.

Note that the US market Vibiemme machines are fitted with a ~2.8 mm diameter restrictor in the upper thermosyphon line. Another idea (unproven) I had is shown by the schematic below which is representative of the Quickmill hx machines. The temperatures are real but the actual construction never took place - those magic stumbling blocks - time, money, space constraints. In this schematic, the solenoid valve would control grouphead temperature by shunting the thermosyphon flow through finned piping in lieu of the group.

Expobar machines (Office, Pulser) can EASILY be retrofitted with a 2.50 mm restrictor in the thermosyphon circuit to dramatically reduce the flush requirements. And, if a 2.50 mm restrictor reduces the flush, maybe a 2.20 mm orifice would eliminate it?

terryz wrote:There is an even better solution by way of a device we will be installing on Malachi's Briccoletta (Soon to be referred to as the Bricc House!)

What ever happened to the Bricc House?

Super old thead, but this is not the first time it has been resurrected.

Eric, you were looking for a proper solenoid valve to use in a group head bypass line in the thermosiphon loop. You mentioned it also in this post Buyer's Guide to the Vibiemme Domobar Super

You didn't say exactly what characteristics you were looking for. Would a solenoid valve like this one work?

http://www.coleparmer.com/catalog/produ...ku=0861792

It is a 1/8" NPT 2-way valve that handles a temperature range from 14 to 284°F. It's inexpensive. You'd need an inexpensive way to control it... a PID device of some kind?

ASCO has 2-way and 3-way NSF certified 1/8 and 1/4 inch valves in the 8256 and 8356 series, but the temperature they can handle is limited to 180°F.

Skip -

Firstly, thanks. Yes, I do believe that valve would work as depicted in my sketch.

However, since that time (Yawn ) there have been substantial changes in the high-end home espresso machine offerings. The trend is clearly towards a "flush-n-go" machine and that flush being little more than a cursory screen flush.