Herms Questions

[Seveneer]

A quick google and this bloke has a 2.5 ltr set up.

Well "this bloke" is me and this thread explains the sudden surge in hits on my web site from Oz

My heat exchanger is currently made from a 300mm x 150mm OD copper pipe, sealed at one end, with a 2.4 kw element in it as well as a coil of 10mm copper probably about 10 foot long. It holds about 4 litres of water as a water bath and does a good job of maintaining and rising the mash temperature of some big (20kg plus) mashes. It's controlled by a PID controller and the water bath in the heat exchanger is typically a degree or two above the temperature I want the wort to be.

For me, the benefit of doing it this way compared to recirculating through a coil in the HLT is the ability to raise the temperature for step mashes or mash out. I can raise the temperature of the grain bed from 66C to 75C in about 15 minutes which is good enough for me.

I hope this helps.

/Phil.

 

[Lukes]

Well "this bloke" is me and this thread explains the sudden surge in hits on my web site from Oz

Welcome to AHB Phil and thanks for the extra info on your system.
Impressed with the use of the wine vat's.
Should I have called you chap instead of bloke.
Anyway Google is our friend.

 

[lokpikn]

OK Well it seems to have a separate heat exchanger is the go so i will either get one made or even sacrifice a keg to make one out of. I will wait and see what my mates have lying around.

2ND QUESTION

RE:TEMPERATURE SENSORS

Once again there seems to be a few types here to tuse as i will be using a PID the two main sensors im looking at are K-Type And PT100

( http://auberins.com/index.php?main_page=in...f917f723b830593 )

The K-Type seem very obvious to fit i would just weld the right size bolt on and drill to fit or drill and tap dependent on the thickness of material im fitting into. The PT100 seems to be more specific in the temperature sensing as quite a few people seem to want to upgrade from K-Type to PT100. It appears the PT100 can be mounted through a thermo couple but this defeats the purpose of having a submersible sensor. How would this be hard wired to a projet so its not just flopping around and waiting to be torn off.

AT the moment the K-Type seem the way to go what do you guys have to say on this ?

 

[Linz]

DON'T SACRIFICE A KEG !!!!!!!!

E-bay/purchase a 5-10lt urn(even use one of the cheapy office urns[7lt from memory] from Big W) and use the PID to turn it off and on

I think mine is a K type probe??

 

[Seveneer]

Welcome to AHB Phil and thanks for the extra info on your system.
Impressed with the use of the wine vat's.
Should I have called you chap instead of bloke.
Anyway Google is our friend.

Thanks Lukes. Yes, perhaps it should have been "that jolly English chap" but bloke's just fine.

Looks like a good forum, I may well stick around

/Phil.

 

[ArnieW]

OK I am looking at upgrading my brewery to a electric HERMS setup. I will still be using standard ball valves at the moment would like to change to actuators but the cost is out off reach at the moment but looking at a few PID temperature controllers and probes from Auber Instruments in USA. I will be looking at 1 or 2 3600 watt elements that will be ran separately and will have my electrical side beefed up properly to take the load.

Hi lokpikn, and welcome to the fabulous world of HERMS B)

I guess I've tried just about every config for HERMS and RIMS over the last 7 years over about 200 brews ... and still tweaking and learning and enjoying the process.

A few thoughts to throw into the mix ...

I'm not convinced that PID control is necessary for HERMS (oops, taking shelter in case flames appear ). I say this because even with a small dedicated heat exchanger, the heating from HERMS is really quite gentle, and the thermal mass of a mash tun full of grains is way bigger than the liquor passing through the heat exchanger. HERMS is as simple as figuring out what your system heat loss is (the difference between HLT/heat chamber temp and the liquor fed back into the mash tun) and then dialing your HLT/heat chamber to mash target + system heat loss. In theory a PID controller might hit mash temperature quicker, but again with the thermal mass of the tun and the capacity of the heating system, I doubt the difference would be noticable. But, if you want an easy control solution, then PID might be the answer. I'd suggest a mashmaster controller would be just as effective if you want to go that way though, and probably much cheaper.

I began with a HERMS that had a 20 litre HLT with a 2400W element and it worked out ok but a bit slow. My current HLT is 40 litres with a 3600W element in it. In a perfect world, it would be nice to step quickly, say a couple of degrees per minute. But in terms of making good beer, I don't think it matters that much if you plan your brew around your system. As an example, if you want to do 30 mins at 64C and then 30 mins at 70C for a particular profile, and it takes 30 minutes to jump from 64 to 70C (a particularly slow system), then you could stay at 64C for 15 mins, do the step up for 30 mins, and rest at 70C for 15 mins and get pretty much the same profile as intended.

Everybody has their own perfect solution, and there are just about as many configs around as there are brewers. In case it is helpful there is more info on what I'm up to here.

cheers, Arnie

 

[poiter]

I was lucky enough to score a 10L urn cheaply second hand. It has a fairly sensitive thermostat. I made a copper coil to fit inside, about 3m long which comes half way up the urn's height, ie about the 5L mark. It's connected via hoses to a short, below the surface manifold, to the mash tun.

It was a simple matter of configuring the water temp to the desired mash temp with a thermometer in the urn water while noting the numbers on the thermostat dial. In my case there is roughly a 10 deg difference between the two. 5 L of water heats up pretty quickly and even with fairly slow recirculation thro the pump enables the mash temp to be even and stable and to do step mashes easily. Very clear wort goes into the kettle.

I like to fiddle with dials and stuff so I like the process to be fairly manual. It doesn't necessarilly make better beer, but it's fun to play with.

 

[kirem]

I have used both a PID algorithm and a simple on/off solution on a HERMS system. My experience was that using PID and in particular the auto-tune feature on the auberins controllers did a better job of hitting the required target.

My take on it is that although the temperature of the mash is the goal, the risk of overheating the thin part recirculating in the coil is greatly reduced by using a PID algorithm.

It also means that I can use a very powerful heat-exchanger for my system (3.6kW in about 5L) and the controller knows the rate at which the system heats up and cools down. This means that the element can be pulsed for very fine temperature control (keeping at set temperature) and turned on full power for quick temperature changes (60 to 70degC) and I can have a high flow rate through the heat-ex.

Although I haven't used an on/off controller with my current heat-ex I think turning a 3.6kW element off once the target temp was reached would not prevent overshoot and denature the enzymes. You could probably set the off temperature lower by trial and error and prevent overshoot, but this seems clumsy.

In basic terms the PID algorithm is setup to know the ability of your system to heat and more importantly to stop heating. An element doesn't stop heating immediately the power is switched off.

In my opinion, the ramp soak PID from auberins is ideal for a HERMS setup.

Here is a thread on my setup, I'll take some more pictures tomorrow of it in action.

http://www.aussiehomebrewer.com/forum/inde...mp;#entry312048

 

[lokpikn]

Thats a good setup sort of thing i have in mind. I was thinking copper coil as it should have a better heat transfer than cooper and might see if i can flatten it a bid like yours for surface area. Only thoughts at the moment.

 

[kirem]

I specifically choose SS for the coil, so I can clean it with hot caustic. Copper doesn't like too many cleaning chemicals.

Obviously copper has better heat transfer properties.