HERMS System

[Goessermuskel]

Hi Everyone,

I'm new to the forum and thought I introduce myself by posting a question.
I have been allgrain brewing for a couple of years now using an esky type setup.
Has been working well so far and I have managed to brew the odd decent beer. I am currently looking at building my own HERMS setup and have done a bit of research on the net. I would like to start with something reasonably simple and manual and then upgrade by adding automation down the track. So I came up with the process diagram attached. I just wanted to put it out there and see if any of you with HERMS experience see anything obvious that I should do differently.
One specific question I had is how to best control the flow of the pump and what is a good flow rate for a 50L keg type mash vessel? I would imagine that it is important to get a nice and even flow rate through the grain bed and not pump too fast.

 

[sponge]

I think you'll find most brewers use a ball valve on the outlet of the pump prior to the inlet of the HEX.

After a little more reading I found a few brewers who placed the ball valve on the return inlet to the MT and I ended up going down the route. I was always concerned that there may be a little too much force on the actual outlet thread of the pump when opening/closing the valve and prefer having it on the MT return. Have the valve as open as possible but not so much that it compacts the grain bed.

 

[TheWiggman]

As above, do not choke the suction side of the pump. Use a ball valve somewhere on the discharge side before it returns to the mash tun.

Also, consider measuring the temp of the mash liquor coming out of the pump returning to the MT. You can control the temp of your mash by measuring the HLT water (some do)If doing this, you'll want recirculation in your HLT to ensure even temp throughout.

"Good flow rate" is whatever a March 809 puts out at full throttle.

 

[mofox1]

+1 to the valve on the wort return. I've had a (plastic) pump head break due to the pressure of opening and closing a stiff valve. If you have a good quality pump with a stainless head then no problem!

Consider an agitator on the HLT, or a separate pump to cycle the water. This will ensure the water is mixed well to avoid hot/cold spots.

Draw out your plans at all steps in the brew cycle - paying attention to what hose goes where, including fill & cleaning/draining!

Most of my inspiration was taken from http://theelectricbrewery.com/. Don't be too overwhelmed by the detail - you can easily ignore all the control sections and use a STC-1000 in a thermowell to control the HLT (although depending on the element size you may need the HLT to control a separate power relay).

Which also brings us to element size... go as big as you can (err - safely), the more juice the faster you can heat. I have 15m of thin wall stainless coil in my HLT with a 5500w element. From memory it could heat 55L at a rate of 1deg/45sec when it was around the 60deg mark (with nothing going through coil).

The main deficiency in my setup is the wort pump - pumping through 15m of coil seems to reduce the flow rate quite a lot... possibly around the 5L/min mark. It's a keg king (kaixin) pump and does the job... but you may want to consider a better one (chugger/march - see site sponsers).

Good luck, and welcome!

 

[Goessermuskel]

Thanks for all your responses guys, much appreciated.
Somewhere on the net (can't remeber where) I have seen someone using a little pinch clamp on the silicone hose to throttle the pump. Anyone have any experience with those? Also I'm not sure if I understand sponges comment about having the throttle valve in front of the heat exchange coil or after. Does that make any difference? Pressure would be the same anywhere in the line.
I'll let you know how I go once I have built something.

 

[TheWiggman]

Pressure will be higher before a throttled valve than after. I too have seen the pinch valve and they will work, but considering I paid in excess of $1k for my system an extra $13 for a tidy ball valve didn't break the bank. Plus it has much better control when fly sparging than a cheap little pinch valve could.

 

[Adr_0]

Looks like somebody has seen a P&ID or two in their time...

Since it looks like you are draining from the MT to the kettle, and then the kettle to fermenter, you will have a 2/3 tier setup and the top of your mash tun/HLT may be quite high (fermenter height + kettle height + mash tun height + 2 x 100mm for buffer height/valves/etc). If you connect a line/valve from the pump discharge to the kettle, this will allow you to have a single tier system and have much more flexibility in working heights. If you're going for a tiered system that's fine of course.

Ball valves on the suction of pumps are fine, as long as you only use them for on/off which it looks like you are going to do.

Discharge is definitely best on the downstream side (past) the heat exchanger, as it ensures it remains full. It depends on your layout to a certain degree, but it's an excellent rule of thumb and there should be no reason you don't follow it.

One other thing to think about is air pockets, line lengths, insulation and volumes. That's four, but they all come down to how well your system will actually work and respond. Try to keep downward slopes vertical/straight coming into pump suctions to make sure you don't; try not to have high point loops; heavily insulate your line from the heat exchanger to the mash tun; etc. Have a think about these things and how they impact your process control, and how you can resolve them. Don't hesitate to ask on the forum as you have done.