hbuchtel wrote:That is a great idea! One consideration is how the valve* would affect the flow of water from the piston to the puck . . . I think it is important not to have any tight spots so that there is a lot of feedback from the flow at the puck.
*valve: Did you mean that you could switch a valve so that pressure from the lever could make espresso OR fill the steam boiler?
Does this picture show what you mean? (proportions etc way off . . .)
image: http://www.home-barista.com/forums/userpix/177_SSL22581_1.jpgNo comments on your other ideas yet, more reading and thinking to be done!
Henry
Hello Henry,
That is correct, A valve would do as your diagram suggests. At the same time the lever ratio could be changed. That may not be necessary as the boiler feed pressure would only be about 1.3 Bar max at 260°F. I might suggest a flow restricter, though, to even out the admission of water to the boiler. Stop the lever pressure and the steam stops. Also, a one way valve would prevent steam from entering the piston.
A suggestion is that the steam boiler would be a flash boiler, operating as a wet boiler only when steaming. That is how the simple two heat temperature pump machines work. A large thermal mass at a high temperature giving off heat to a liquid. Obviously, There has to be enough mass at temperature to steam a reasonable amount of water. An OPV would be suggested!
The use of another diverter valve would be to allow water to go to a hot water tap rather than the group. That would allow construction of other drinks.
As to the questions for the HX, Perhaps someone can do the heat transfer equations.
A PID and high wattage element would be necessary to keep an even temp in the kettle.
Consider that one successful machine had a poppet valve like an IC engine as the diverter and anti backflow valve at the Group ( La Peppina has the washer. Since the HX entrance location is relatively inconsequential, that may work.
A spreadsheet seems to be in order to keep track of all the feature possibilities.
I operate on TLABR! = That looks about right. So, I am wondering what would happen if I were to attach a lever and pump to my old DeLonghi Pump machine with the Stainless steel boiler/monoblock????? And, if that works, a PID? Seems that There was an article on CG that dealt with a PID mod'd Hamillton Beach that gave great results.
Probably would require flushing after steaming though. Is that another thread????
Pleasant thoughts to all!
richard
PS It just dawned on me where you live!
PPS It may be an Idea to have an editable 1st page like LMWDP to hold the features and ideas to make back tracking easier. An index so to speak? That would be a good place for un-answered questions! You could do that by editing your first introduction page as needed.
)
