I'm Building A Herms Too!

[Sammus]

After seeing AndrewQLD's recent thread about his HERMS.. I realised I had a bunch of copper pipe and a spare PID controller, so I decided to give it a go too! Haven't got to using it yet, but here's the story so far:

First of all, I read The HERMIT Brewery's HERMS design specifics, I liked the cut of his jib so decided to roughly follow suit.

I had about 5m of 1/2" copper tubing lying unused, handed to me as someone elses failed project - so that part was decided already (I would have prefered to go with a longer length of 3/8", but this was built on a budget!) I annealed it on my gas burner - damn was that tedious, it had been annealed it some spots before hand and formed into a retangular square coil and was a bitch to get onto the flame of my burner, but patience and 2 sets of vice grips eventually got their way.

I picked up a 5L handy pail from bunnings and drilled a 38mm hole in it:

I also got a woolworths 2200W corded kettle and ripped the element out of it (came with a nice gasket, boil dry protection and an activity light for $13!):

Then, with a $5 camping mat from the reject shop and a roll of duct tape, I insulated my pail - I got a total of 3 layers on the sides and bottom, 5 layers on top - and still had some left over!:

Then poked some holes through the lid with a handy plastic reamer I had in my RC toolbox, tapped a thread into the corner of a brass elbow for the K-type thermocouple I also had lying around, and came up with this:

Kinda handy the PID I had kicking around is a Fuji PXR3 with ramp/soak programmability - but pity it only reads in degrees F, oh well, can't complain I guess! I'll let ya'll know how it goes once I've tuned in the PID and given it a test run

Any comments?

PS come to think of it, the ramp/soak functionality won't come in ALL that handy as I dont plan to do a lot of step mashing (what with all the well modified malts today etc) - I did this more to use up spare crap I had lying around, and to further procrastinate (eh now I have to do some actual work...)

 

[AndrewQLD]

Great work Sammus, I like the idea of the 5 lt bucket, a lot less water to heat will mean faster ramp times.
Keep us posted on your first brewday.

Cheers
Andrew

 

[Justin]

Ha ha, nice one Sammus. I built mine to completion yesterday out of a pressure cooker. Will post pictures soon as well but basically the same lines of Andrews and your system. Looks the goods.

Cheers mate.

 

[snagler]

Sorry for the stupid question Sammus but what brand is that kettle you bought? I would like to fit an element like that to my HLT.

 

[Sammus]

Sorry for the stupid question Sammus but what brand is that kettle you bought? I would like to fit an element like that to my HLT.

'Kitchenmaster'

There are cheaper options - you can get a cordless kettle from Go-Lo for $10 - I originally picked up one of these then took it back because I forgot I needed a cord... then I realised any computer PSU cable would do...

I also read about someone getting one for $2 from a budgo shop, I could never find one though.

 

[Zizzle]

Looks good sammus, I was planning on the same setup for my brewbot eventually.

I already have a pair of those kettle elments in my HLT and another pair in my kettle.

Beware that most computer power cords are rated for either 7.5 or 10 amps, but don't really like to run an element for very long. Can get very hot and squishy.

For my boiler I bough some of these http://www.jaycar.com.au/productView.asp?ID=PS4013 and used 15amp mains cable. Using that setup, I can not detect any warms with my hand after a 60 minute boil.

Another interesting note: quite recently the price seems to have gone up on those cheap jugs. The last one I bought was $8.99, but they all seem to be above $12 now. China putting it's prices up, or retailers getting greedy?

 

[warrenlw63]

For my boiler I bough some of these http://www.jaycar.com.au/productView.asp?ID=PS4013 and used 15amp mains cable. Using that setup, I can not detect any warms with my hand after a 60 minute boil.

Wired my HLT cord up with the same plug Zizzle. You're right they seem a bit less prone to going hot and soft like conventional plugs. :beerbang:

Warren -

 

[Sammus]

Well I did a tester today. The scenario is: HLT has about 20L in it at 60C. I turn the element off in the HLT and recirc through the heat exchange at just over 3L/min. Once the HLT controller hit 61C I started timing, and it hit 62C after 1min 40s.

I reckon this is pretty good considering it was 20L of water (no grain or anything) and the theres no agitation/stirring happening to the water bath in the heat exchanger. The PID parameters are untuned to this system(they were tuned into something a while ago, dunno what though... probably my kitchen kettle from when I calibrated the TC) - but I doubt this will have too significant an effect on ramping speeds.

So I'll have to throttle the pump a little more and whack a stirrer in the HE.

I reckon I should be able to get close to 1C/min

woot!

 

[Tony]

just a quick post on another method to fit an element to a SS vessel

this is a side project to brewing i have going. I didnt feel so safe having a raw flame under this project so electric we go. I have a burst fire TRIAC controller on its way from england to run it

Would work well in a HLT or RIMS setup.

all it needs is half a 1" BSP SS fitting from blackwoods for $9

cheers

 

[Sammus]

Hmm the HLT wont go above 2C below the setpoint on my controller, maybe I need to insulate my lines better - I thought it wouldnt lose that much temp though. I'm using the cheapo really thin clear plastic tube. dunno what its made from, vinyl perhaps? Ill have to get some silcone hose to see if that helps.

And on another note, I decided to run my PID through its auto-tune program, and now it wont even reach the setpoint! hmm lucky I decided to sus this all out a few days BEFORE brewday

 

[Tony]

PID autotune..... never seen one work yet.

here is a basic way to set up your PID, it doesnt work all the time but may help.

Set the P, I and D to 0 in the controller

increase the P slowly till the temp starts to Ocilate, the bigger the volume, the longer this will take.

Time the ocilation duration, multiply by 2 and enter this as your I value.

this should get you close.

if it hunts, try increading and decreasing the P value to see if it settles out.

hope this helps a bit

cheers

here ia a good read on the subject

http://www.newportus.com/Products/Techncal/techncal.htm

 

[Sammus]

OK something isn't right.

I have calibrated the HLT thermometer, probe in the HE outlet, and handheld digi in boiling water, and the handheld agrees with both the HE outlet probe and the HLT probe seperately at working temps (60-70C) (a bit hard to compare them directly )

The HE outlet is reading a constant 69.8C, and the HLT is reading a constant 66.8C.

The return hose from the HE to the HLT reads 69.8C at the beginning, and 69.4C at the end (these are fairly constant reading that doesnt vary much at all - the PID is doing its job!)

Now in my double aeroflex-insulated HLT that loses nay a degree over more than an hour is somehow just not cutting it, even with the lid on. The pump is running at 2L/min now.

Any suggestions why this might be happening? my HLT insulation seems second to none yet somehow with 69.4C water running in it just wont top 67C in there (read from 2 different spots simultaneously, within 0.5C of each other)

Its frustrating me something shockin! The HLT doesnt feel warm to the touch at all, not that much heat could be dissipating! theres a nick over 20L in there, so thats about 10min to displace all the water. Losing 2C in 10min seems a bit unbelievable, given its stand up performance in the past...

How bad would it be for the beer to have the wort constantly heated to 70C but the bulk of it at 67C? would that do some irreversible enzyme damaging inside the heat exchanger?

 

[Thirsty Boy]

Sammus,

Could go in a different HERMS direction.

I have the coil in my electric HLT and I keep the HLT at 80C via a PID (but a setpoint controller would probably do).

The pump is only run in order to make a temp change to the wort. So if it cools down or I want to do a step.. then I flick on the pump, which drives wort through the coil in the 80C HLT. Things heat up at about 1-2 degrees per min and I have had no conversion troubles so I doubt if too much damage is being done to the enzymes.

If you want it a bit more "auto" You could control the temp of the HLT with a nice simple thermostat.. and drive the pump off the PID...

Or you could constantly circulate through a loop that excludes the heating coil, measure temp at the outlet of teh Mash Tun and use the PID to switch a valve to re-direct through the heating coil when the temp needs altering.

mmmm options

 

[AndrewQLD]

OK something isn't right.

I have calibrated the HLT thermometer, probe in the HE outlet, and handheld digi in boiling water, and the handheld agrees with both the HE outlet probe and the HLT probe seperately at working temps (60-70C) (a bit hard to compare them directly )

The HE outlet is reading a constant 69.8C, and the HLT is reading a constant 66.8C.

The return hose from the HE to the HLT reads 69.8C at the beginning, and 69.4C at the end (these are fairly constant reading that doesnt vary much at all - the PID is doing its job!)

Now in my double aeroflex-insulated HLT that loses nay a degree over more than an hour is somehow just not cutting it, even with the lid on. The pump is running at 2L/min now.

Any suggestions why this might be happening? my HLT insulation seems second to none yet somehow with 69.4C water running in it just wont top 67C in there (read from 2 different spots simultaneously, within 0.5C of each other)

Its frustrating me something shockin! The HLT doesnt feel warm to the touch at all, not that much heat could be dissipating! theres a nick over 20L in there, so thats about 10min to displace all the water. Losing 2C in 10min seems a bit unbelievable, given its stand up performance in the past...

How bad would it be for the beer to have the wort constantly heated to 70C but the bulk of it at 67C? would that do some irreversible enzyme damaging inside the heat exchanger?

Sammus,
Have you tried stirring the hlt water to see if you are getting thermal layering?

You will find it easier to maintan temps when you actually have a mash in there, the grain will help to retain the heat.
Is the return hose insulated as well?

Cheers
Andrew

 

[Tony]

I have the HERMS coil in the HLT too.

I use a simple setpoint temp controller to set the temp in the HLT

I have a temp probe on the outlet to the hermsto monitor the temp of the return wort and adjust the HLT temp till i get the return where i want it. The HLT temp will vary depending on the flow rate and SG of the wort. I find as it converts i need to increase the temp of the HLT to compensate.

Im not quite clear on exactly how your running yours, i cant make sense of it, but its probably just me. Its early

cheers

 

[Sammus]

I have the pump constantly recirculating, and a PID controlling an element in a pail full of water and copper coil. The PV for the PID is taken from where the coil exits the heat exchanger. So the idea is that the water in the HE will heat up and consequently cause the wort running through it to heat up to a certain amount.

The PV does hit the set value on the controller, so theres no issue there with agitation (it might just get there quicker if I do have it - the fact remains though that the liquid exiting the HE coil is at the temp I want it)

For the test run I was treating the HLT like the MT. I have an electric HLT that is well insulated so I expected performance to be similar. With about 20L of water in the HLT I heated it up to 60C, then hooked up the HE, so it was taking 60C water from the HLT and throwing it back into the HLT. The temp of the water (read wort) exiting the coil gets up to the SV fairly quickly, and if that set value is more than about 5C from the the temp measured in the HLT, then the HLT temp increases at an acceptable rate as well.

Once the values get close though it stops working so well. Upon running for over an hour last night, even though the water exiting the HE coil was a set value, the temp in the HLT just wouldnt get within 4C of it. IT must be an insulation problem in the return line and HLT.

The return hose isn't insulated, and I made a mistake in my last post, there is a 1C differential between the exit of the HE coils, and the end in the HLT. So that accounts for 1 of the 5 degrees
hmm well, I'll have to do a test with grain soon. I'll just mash in like normal and use the HLT to hold that temp (lets hope it can) - then see if I can ramp up to a mashout (which I don't normally bother with...)

Werd.

S

 

[AndrewQLD]

How is the liquor re-entering the HLT, if it is spraying in or dropping from a height you will get a fair bit of heat loss, here is a pic on my return manifold, it has the controller probe in the end of it. As you can see it is just on the surface of the mash.


Cheers
Andrew

 

[Sammus]

I've got the end of the return hose just under the surface of the water - I havent built a return manifold yet but when I do it will be something like yours.

 

[Tony]

ahhhhhhhhhhhh i think i see whats happening

here is my take on what your doing

you are attempting to raise the temp of your HLT by using a seperate HERMS coil vessel as an experiment you are measuring your coil exit as your PV to control the element in the seperate herms vessel. there is no heating going on in the HLT while this is happening, its just a pretend mash.

Is that right ?

you said:

Once the values get close though it stops working so well. Upon running for over an hour last night, even though the water exiting the HE coil was a set value, the temp in the HLT just wouldnt get within 4C of it.

Thats a clue. a big one!

You are using a PID. PID's will do this if they are not set up corectly. Its called under or over dampening, its been a while. The PV never quite reaches the setpoing.

but if you are meeting the setpoint cause its the outlet of the coil your reading, not the HLT tenp its self than iths is not the case.

hmmmmm

it could well be haet loss. the small amount of energy you put in through the coil is lost, as your temps get higher, efficiency is less, making it harder to get there.

thats a tricky one, I just use it to hold temp, not step it. you dont really need to step mash these days anyway.

sorry i cant help. Its a bit of a bee there to see kind of thing hey

cheers

 

[Sammus]

ahhhhhhhhhhhh i think i see whats happening

here is my take on what your doing

you are attempting to raise the temp of your HLT by using a seperate HERMS coil vessel as an experiment you are measuring your coil exit as your PV to control the element in the seperate herms vessel. there is no heating going on in the HLT while this is happening, its just a pretend mash.

Is that right ?

Yes

you said:

Once the values get close though it stops working so well. Upon running for over an hour last night, even though the water exiting the HE coil was a set value, the temp in the HLT just wouldnt get within 4C of it.

Thats a clue. a big one!

You are using a PID. PID's will do this if they are not set up corectly. Its called under or over dampening, its been a while. The PV never quite reaches the setpoing.

but if you are meeting the setpoint cause its the outlet of the coil your reading, not the HLT tenp its self than iths is not the case.

Second one, its reaching the setpoint....

hmmmmm

it could well be haet loss. the small amount of energy you put in through the coil is lost, as your temps get higher, efficiency is less, making it harder to get there.

thats a tricky one, I just use it to hold temp, not step it. you dont really need to step mash these days anyway.

sorry i cant help. Its a bit of a bee there to see kind of thing hey

cheers

Yeah pretty much the only option I think (heat loss). I wont be stepping much (if at all) anyway - its mainly to put some copper pipe and a spare PID to use (and to procrastinate my studies of coursE), my MT holds temps fine on its own, I guess Ill just get some clear runoff then good enough!