View Full Version : Boiler questions

02-05-2013, 07:41 AM
We are buying a new brewing system from a manufacturer. However, their price for the boiler they recommended was a bit too much so I have looked at other options.
I have found one, barely used, cheap, 90KW electric with 115kg/h at 10 bar.
The brewing system is a double brewing system; with a mash kettle, lauter tun and copper. If needed, we want to be able to do double brews but for the first year we're looking at something like one brew every two weeks.
The 90W kettle was more than our current electric installation could handle, if we want to have coolers, pumps and whatnot running at the same time.

Is it possible to down-tune the boiler? Like, use perhaps 70KW?
If we use pre-heated feed-water, that should speed up the steam boiler and perhaps take a few watts off.
And 10 bar is more than we want. We're looking at 1-3 bar, which I've read is the best option when dealing with stainless steel. In this case, the mash kettle and copper have dimple jackets for steam. So that could take a few watts off the load too? And if we lower the pressure, the steam production should be increased from 115 kg/h to... I don't know, more per hour.

I have never had any experience with steam boilers, just a little knowledge picked up here and there. So feel free to help me out :)

02-05-2013, 07:50 AM
I have asked our boiler service company a very similar question. But it was a gas boiler not an electric. Their answer was yes, but it would take some work. Not sure it would work on an electric. But I would call a boiler service company and or the manufacturer. Not sure how it would work with electric, smaller heating element...?

03-10-2013, 01:36 PM
Boiler Techs are going to speak to you in American units rather than metric.
That equals Boiler Horsepower, and PSIG.
Pressure in BAR is near useless for mechanics in the USA.

This model seems to operate at quite an unnecessarily high pressure for a brewery application.
Depending on how many elements the unit has, you could disable one to decrease the actual KW the unit is designed to output.
The main pressure control that operates the unit in the case of most gas fired boilers can be run lower than design, so yours also should in theory be able to be dialed down.
Not knowing the design parameters of this machine, its possible that taking this de-tuning measure too far could compromise the units ability to carry a load correctly, but said experiments detailed above are quick and easy to perform with some basic electrical skills.
The KW of each element in the unit can be calculated using OHMs law if they are not labeled clearly. This is assuming it has more than one which is likely.
I have run 50 HP Scotch boilers designed for 50 PSIG at 15 PSIG as an example.

03-10-2013, 03:48 PM
Really need to get a boiler technician working with you. Your heated brewing equipment is undoubtedly restricted to 1 bar and lower steam pressures. This is low pressure steam. What you are looking at for a boiler is high pressure. To put the two together would require a major refit and isn't worth it. You also need to get your electrician to look at an electrical plan. 90kW is lots for a small brewery. You would have to have quite an electrical service to cope with that and all the other electrical equipment you have to run. Use natural gas if you have it. Cheaper to run and less electrical load for you to plan for. Good luck.

03-11-2013, 06:46 AM
Well put PK.