Jake_G wrote:Correct.

DB machines running E61 groups do not use heat exchangers. My suggestion in this context is only that the HX would isolate the steam supply from the brew water and pump, and would allow for steam to enter the "vaporizer" as Slayer has dubbed it.

There is significantly more energy required to turn water into steam than there is to make steam hotter. That said, the idea of taking wet steam and making it hotter means that it must become completely dry first. Thus you need a beefy thermocoil vaporize all the water droplets in the steam, but it needn't be nearly as beefy as one trying to turn water (even hot water) into steam.

SO does the Slayer use a thermocoil after the steam boiler to vaporize dry the steam? Would you have a link to share on this?

I'm really tempted to grab a thermoblock from a junk machine and just wire it up to a switch feeding my steam wand. I'd need to fab a new copper steam pipe, though and I haven't found a supplier of the style of brass fittings used on commercial machines.

I admire your willingness to try things. NO doubt you have lots of fun doing it too.

I haven't seen the interior, so I can neither confirm nor deny that they use a thermocoil, it seems probable given the application. The picture I posted below is from the Slayer website. Based on the described workflow of providing instantaneous steam at 2 different user-defined temperatures on each of the two steam wands, I would choose a thermocoil...

This kind of "steam on demand" is a perfect application for a thermocoil. They probably have some sort of proprietary fixture that they designed specifically for this purpose, but I bet it closely resembles a thermocoil at its core. Maybe not. Of one thing I'm certain. Decent achieves instantaneous, temperature controlled steam using a thermocoil. So I know it would work in Slayer's application.

Cheers!

- Jake

henkc wrote:What I haven't seen discussed much is the one big advantage of thermoblocks. They heat up very quickly. The way they work - on demand heating - is also a great deal more energy efficient than keeping water hot and so on. https://onlinelibrary.wiley.com/doi/pdf ... 10.00971.x

The problem I see here is that the comparison is always made between a thermoblock machine designed down to a price which is typically around a third or less of the price of an entry level HX.

Innovative design concepts will always face opposition from those otherwise invested or lacking imagination. That's how a naysayers post here, discussing his own personal experience, becomes a condescending statement in a quotable quote. Unfortunately ignorance sometimes prevails.

Are there any really high-end thermoblock machines?

How about Slayer for steam vaporization (only a guess but I'd put money on it)? Or one of the potentially greatest innovations in espresso machines for decades, the Decent Espresso Machines ... also associated with Scott Rao, one of the greatest minds in coffee?

Tonefish wrote:Innovative design concepts will always face opposition from those otherwise invested or lacking imagination. That's how a naysayers post here, discussing his own personal experience, becomes a condescending statement in a quotable quote. Unfortunately ignorance sometimes prevails.

How about Slayer for steam vaporization (only a guess but I'd put money on it)? Or one of the potentially greatest innovations in espresso machines for decades, the Decent Espresso Machines ... also associated with Scott Rao, one of the greatest minds in coffee?

With a HX, you get free temperature stability and don't need a particularly large heating element because the steam boiler acts as a thermal mass and water has a very high specific heat. I recall reading a discussion of the thermoblock problem. It may even have been by the DE team. Someone had issues using PID to dampen the temperature change because the thermoblock temperature dropped much too rapidly so you'd need a ridiculously overpowered heater to keep up. It looks like DE threw more computing power at the problem and I'd guess that the amount of cold water that gets mixed in with thermoblock water tapers from beginning to end of shot in order to compensate for the drop in thermoblock temperature which wouldn't have been feasible before the smartphone boom because processing power for embedded systems wasn't there. Option B would be to surround the whole thermoblock in cast iron, but then you'd lose the cost and warm-up time advantages and would be better off going back to a HX design.

I'm intrigued by the hot/cold water mixing approach DE is taking and wonder how hard it would be to apply to a compact HX that ran the steam boiler at a higher pressure (1.5+ bar) for better steam power and allowed on-the-fly brew temp control without requiring more power. I think we'll see some real neat consumer/prosumer espresso machines in the next few years.