Submitted by Knackmanic t3_zb0waw in DIY
crazybutthole t1_iyoltzi wrote
Is it possible? Absolutely yes it is possible. I work on Heat exchanger systems that do exactly what you are describing.
Problem is, it is not economically viable. (For the minor convenience of controlling the flow to your coffee machine, you would be adding so much additional cost to the machine. Additionally, you would be adding alot of additional parts which could break and cause increased repair costs. Its just not worth it)
My systems i work on are for defense use. (Keeping radar systems cool so electronics dont overheat) in those cases it totally makes sense to spend thousands of dollars installing and maintaining pressurized systems that react to (temp, pressure and flow rate, and increase or decrease rpm's based on the additional cooling or pressure needs of your system during certain modes of operation. - ie if you are in southern california its much warmer than alaska. If you are operating at high power there is much more heat dissipated than in standby or low power, etc etc)
In the case of a coffee machine - you would be creating a machine that costs $800-1000 plus upkeep costs, and most folks would never want to pay that for some specialized coffee production.
Knackmanic OP t1_iyop0wl wrote
The machine I have is quite customizable and cheap. Users are installing pressure sensor. I was wondering if I could skip the pressure sensor which is used as a feedback to modulate the pump current, just by knowing what the pump's RMP/current is.
frzn_dad t1_iyp6wm5 wrote
Depends on how static the other variables are. Hint they probably aren't or others wouldn't be using pressure control.
Also please explain how you intend modulate the current? Most speed controllers adjust voltage, frequency or resistance which do change the current but it isnt a direct correlation the load on the motor at a given speed changes the current.
Fuzzy_Chom t1_iyrpngd wrote
That is what i was thinking. It's possible to estimate flow and pressure based on pump demand (current, etc), but you'd probably want to do so real testing and trending to understand the actual correlation. This is really the only shortcut around modeling every electrical and mechanical stage of the process, accounting for losses, variability, etc. Either way, it becomes a bit of a science project.
John_B_Clarke t1_iyorzf8 wrote
I don't think he's talking about designing a commercial coffee machine, I think he's talking about a one-off hobby project.
And people do pay that for coffee machines. A Jura Giga 6 is about $6000, a Z10 is around around $4000. Neither of those is considered to be a "Pro" machine.
Viewing a single comment thread. View all comments