Raising steaming power of Expobar Brewtus?

#1: Post by **godlyone** » August 23rd, 2009, 4:05 pm

So after PIDing the brew boiler and putting in a rotary pump, I can honestly say that I'm extremely satisfied with the performance of my Brewtus II (now technically a Brewtus III-R i guess lol)

The only thing that is lacking is the steam power. I was thinking of a few ideas to make the steam boiler work better.

1. bypass pressurestat and PID it to a higher temperature thereby producing more steam
2. Somehow lower the water fill sensor so there is less water and more steam
3. Put in a more powerful heating element into the steam boiler

What do you guys think?

#2: Post by **Espin** » August 23rd, 2009, 6:51 pm

Is turning up the steam P-stat an option? How about replacing it with a higher range p-stat?

How close are you to the pressure rating on the steam side?

#3: Post by **gyro** » August 23rd, 2009, 7:15 pm

I would have also thought you could turn up the pressure-stat for the steam boiler a little. Make sure though that you carefully observe the dead band and hysteresis before you do so, and then allow an adequate margin below whatever type of boiler safety valve you have fitted. 1.8 bar I believe is the most common, but make sure you check what you have and stay away from that figure.

A new heating element won't increase your initial steam power, it will just make it recover more quickly, or last longer.

Be careful about messing around with water fill sensors etc. Don't want to leave any of the element in the tank not covered in water.

You could PID it, which would reduce the deadband and hysteresis so that your normal setting could be a little higher, but it won't change what is probably the limiting factor - the safety valve. You can get higher rated safety valves, I have just changed mine from 1.8 bar to 3.0 bar, but you need to check with the manufacturer that the rest of the boiler system is safe to use at the new pressure. You don't want a 3.0 bar safety valve if the boiler explodes at 2.5 bar!

Cheers, Chris

#4: Post by **cafeIKE** » August 23rd, 2009, 7:34 pm

PID on steam boiler trades dead band for reaction speed. You want the heater FULL ON the instant the pressure drops without any power scaling.

godlyone wrote:The only thing that is lacking is the steam power.

What is lacking 'power'?
Is the velocity too low making it difficult to steam?
- Consider a tip with smaller holes.
Does it take too long to steam a large volume of milk?
- Consider steaming a smaller quantity.
Is the quality of the foam poor?
- Consider different milk.

#5: Post by **Arpi** » August 23rd, 2009, 7:39 pm

The BIIIR is also weak on the steam. Maybe because it comes with the single hole tip. I read about the espro 20 oz toroid pitcher http://www.espro.ca/toroid.php and it is marriage made in heaven. It is not fast but it is hard not to make nice froth for latte art.

Cheers

#6: Post by **another_jim** » August 23rd, 2009, 9:07 pm

A 1.8 liter boiler at regular pressure should have far better performance than shown by the Expobar. Even with less electric power. For instance, my little Elektra, with a boiler the same size, and only 900 watts of power, steams far better than any of the Brewtus iterations

It's known that all the tip options are miserable. It could be a problem with the pipe to the steam valve. The steam valve itself is the same as all the other E61 boxes and is not the problem.

August 23rd, 2009, 9:51 pm

cafeIKE,

I would say that frothing is just too slow. I am able to make nice microfoam, but it takes longer than I'd like it. I think it's possibly even faster on a silvia!

I have a single hole and 2 hole, but find that the single hole generally works better.

If I PID'd it and raised the temp, would I be able to set the P,I,D to something in order to get it to react very quickly to pressure drops?

I did raise the pressurestat as high as it will basically go, but to me that's still not enough....

Jim: this is how the steam pipe gets there.. it seems pretty simple:

#8: Post by **cafeIKE** » August 25th, 2009, 12:45 pm

How slow is too slow?

What is the current steam boiler idle pressure?

Do you purge the steam boiler a couple of times before steaming?

You can use a some PIDs in electronic thermostat mode with a 0.5°F dead band. That will give almost instant response. You may be able to run the temperature higher, leaving a decent safety margin for the over pressure valve. However, it would be simpler to change the pStat if the one installed is incapable of sufficient pressure.

FYI, On the Vibiemme Double Domo the 1.4L steam boiler idles @ 1.5bar. A two hole tip [ 0.040 ] steams 4oz in about 30s. On the HX @ 1.1bar, the 2.7L boiler takes about 20s with a two hole tip [ 0.065 ].

#9: Post by **another_jim** » August 25th, 2009, 2:34 pm

I don't know what this converstation is about, unless Ian is pulling your leg. The Brewtus steams slowly because the holes in the tip are tiny, designed for people stepping up from small home machines. End of story.

If you want to to steam faster, change the tip. Do some googling of Brewtus owner's groups for more details.

#10: Post by **cafeIKE** » August 25th, 2009, 4:08 pm

No, Jim, I'm not pulling his leg. Never having used a Brewtus, nor followed its owner groups, I was simply trying to determined enough information to make a recommendation.

Had you posted the above earlier, the thread would be dead. Thanks for wasting all our time.

BTW, ALL the other e61 'boxes' do not share the same steam valves. I'm surprised that you'd make such a misleading comment. About the ONLY thing ALL e61 'boxes' share is intent.