Upcoming induction espresso machine (Heylo) - Page 7

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#61: Post by ira »

If the Unica is not controlling temperature by mixing hot and cold, there is probably no way to have a reasonably fast temperature drop with a thermoblock.

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#62: Post by Shakespeare »

baldheadracing wrote:I don't see temperature profiling as a feature of the Unica, though.
Unica has instantaneous water temperature control using the series of controlled heaters to assist in addition to volumetric dosing.
This includes through its controls and computer management it will allow you to create, program and manage 24 recipes. Where you can still adjust the coffee weight, water volume, water pressure, temperature and extraction time and weight.
It also allow the user to pre-define the amount of water that flows through the coffee puck at any given time, regardless of back pressure. Calculating the back pressure in the puck the Unica also provides recommendations on the grind size after the extraction is performed.
With the temperature management, within .05C, the water temp.is controlled while the extraction is being performed. This is a commercial espresso machine.

This also allows to control the steam wand independently while extractionis in progress.
The water dispenser also has a temp control to allow for different recipes.

I believe both the Heylo and the Unica will be offering some unique options in our never ending quest to be creative.


#63: Post by malling »

ira wrote:If the Unica is not controlling temperature by mixing hot and cold, there is probably no way to have a reasonably fast temperature drop with a thermoblock.
It dos not use a thermoblock, frankly we don't know how they done it, also unlike they achieved that fast warm up and low energy consumption with that.

Francis Vaughan

#64: Post by Francis Vaughan »

A few thoughts on this machine and induction heating.

I think it is important not to confuse the use of induction in a coffee machine with induction cooktops. There is a familial relationship, but it is pretty unlikey that you will find the equivalent of a mini cooktop inside. Rather we are going to see induction as part of a much more nuanced solution to a problem. And this is induction in its basic physics definition, not cooktops.

Induction is nothing more than use of a varying magnetic field to create a current in a conductor. It happens in just about every electrical device we own, bar the most basic things like incandescent lightbulbs and heaters. Transformers, motors, generators, all work with induction.

If we wind back the question to the base requirement - how to heat a small amount of slowly flowing water to a tightly controlled temperature with minimal energy use, we would probably get to a design where a the water flowed though a length of pipe and was directly heated as it flowed through the pipe. The trick being to get the mass of everything else as low as possible to avoid both the need to heat stuff that is just going to cool down again, wasting energy, and not to heat anything up that holds heat, as that will make regulating the temperature harder.

Some back of the envelope calculations provides some idea of the requirements. Say we want to be able to deliver enough water to brew a longish espresso - say 50ml. Then add on the water retaining in the puck, and then the water needed to fill the rest of the brew chain, cavity above the puck etc. Call it 100ml all up. We need to deliver this in 20 seconds. (Numbers chosen to give some leeway and to make the final result easy.) So 5ml a second. Start with water at 20ºC, brew at 90ºC. Thermal constant of water, 4.2 J/ml/K, so 5*70*4.2 = about 1500 watts. Which is pretty serious for a small volume, but right on target in terms of feasibility

Back in the dark ages of electrical goods, we might start with a design that placed a resistive heater wire down the middle of our pipe, and run current through the wire. Not that far from the old electric kettles with exposed heater wire. Kettles born of a bygone age, when life was cheap, and safety regulations were sneered at. Lots of reasons this isn't going to fly.

Another solution might be to just run a lot of power though the metal pipe or water is flowing though. That is going to need a low voltage very high current power supply. A 1.5kW power supply is not small. A 1.5kW transformer running on 50 or 60 Hz mains power weights about 12kg. You could start with a welder. Clearly this isn't looking good either.

The solution is to look to how modern power supplies operate. They run at quite frequencies, initially rectifying the mains, switching it a high frequency, which allows the use of vastly smaller transformers. Basically the cross sectional area of a transformer drops in size as the operating frequency rises. Your 50Hz 12 kg transformer can be replaced by a transformer that sits on a the circuit board.

Now, the fun bit is what happens if we realise that our water filled pipe can be made to look just like the secondary winding of our power supply transformer. We just wind the pipe into a coil, and short the ends together. The high frequency primary side of the transformer couples to the water filled pipe and current flows in the pipe, heating it. The coupling of power across the transformer is - induction.

So, I'm going to guess that the inductive heating system of this machine is more akin to a switching power supply where the secondary winding of the output transformer is replaced with a coil of copper tube though which the water flows. Control of power delivery is pretty simple. Normal switching power supplies control output voltage by controlling the main power switching device. There are one chip solutions that do the whole thing. It isn't hard to imagine a design that uses output water temperature as the target for the control system. There will likely be some interesting aspects to designing the control logic. If it were me I would be thinking in terms of some form of predictive feed-forward control. I don't think a straight forward PID would work well enough. But in the modern world, this isn't hard.

Overall, IMHO, the venerable E61 and its ilk are last millennium's technology. The ridiculous waste of water and energy involved in their use, especially in a domestic machine just isn't justifiable. This is heralding the end.


#65: Post by malling »

Well it's need to be like 1/4 of its current price before it will be the end of that. At the current price it's really only a treat to the absolute upper tier market. With one group and milk foam module you at Synesso Hydra Pricing. Just the espresso module your set back as much as many single group pressure profiling machines. It's a rather steep price for something unproven. The Unica pro that is a all in none module solution is GS3 pricing.

It will take 15-20 years before this has become anywhere near mainstream.


#66: Post by Graymatters »

Hence "heralding."
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#67: Post by pizzaman383 »

Francis Vaughan wrote:A few thoughts on this machine and induction heating.


Overall, IMHO, the venerable E61 and its ilk are last millennium's technology. The ridiculous waste of water and energy involved in their use, especially in a domestic machine just isn't justifiable. This is heralding the end.
Really good stuff!

I think that something like what you describe will need to be productized and modularized to become ubiquitous. I wonder when it will be as cost-effective as thermoblocks.
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#68: Post by Chert »

Very interesting information. I had hoped Crossland was heralding the end of boiler associated energy waste in quality home espresso gear.
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suggestion: Taste n Learn: turbo shots, light roast edition.


#69: Post by gscace »

Just a cautionary note to look at specs and specsmanship with some care. I just took a look at the Unica Pro and some of the videos. I would not go by them as real proof of performance. How, for example, is heat up time being evaluated? In the warmup video it looks like steam production? I don't understand that because heat up time really needs to be evaluated as the time required for the machine to produce the desired brewing temperature at the top of the coffee bed. So I suggest we look at real results and not what looks like salesmanship. Let's look at temperature, pressure, extraction yields in average values and in sections of coffee cakes. Let's have yield and sensory comparisons done against benchmark machines by people whose credentials are impeccable.

Heylo is intended to be a modular system with advanced technology that is best in the world, which is why I'm attracted to the project. We've got people with really good street cred. We are doing the heavy lifting that is required and we are not bullshitting. It's a very interesting time to be in coffee.


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#70: Post by ira »

The cost might get reasonable for home users when someone like a Gicar decides there's a big enough market for a induction module that your average espresso machine assembler can understand and use. One it becomes proven technology, maybe that will happen. But it will likely always be more complicated than an E-61.