I've taken the plunge!

[Staz]

Hi All,

After reading many posts and being inspired I've taken the plunge and started ordering components for a HERMS control box that will incorporate the controls for a pump as well. To keep costs down I'm considering using a pid to control the HLT and fitting it with a coil to act as a heat exchanger. Are there any drawbacks with this approach or would I be better served building a separate heat exchanger? :?

 

[simonranson]

Staz,

I've thought about using the HLT for HERMS, it seems that its quite common in the US. The main drawback I can see is the lag time of heating/cooling the large volume of water in the HLT.

Simon

 

[Staz]

Hi Simon,

I can understand that issue but if the MT and HLT are well lagged is it that big an issue? Has anyone any experience of thjs on the forum?

 

[pjbiker]

Hi Staz,

If you've got a spare couple of hours, the system is discussed extensively here Advice on solenoid valves and PIDs

The main upshot is it is possible and has been done on a larger scale quite simply http://www.lamabrewery.com/System.htm but you would probably be advised to use a separate vessel for more accurate control. I'm embarking on that route myself, using a cheap kettle as the vessel as someone else has already done if you have a search.

I've got a simple temperature controller on my HLT which does the job but a PID doesn't cost much more and doesn't take much more fabrication and is obviously more accurate. I think a mechanical agitator or circulating pump in the HLT would make my temperature controller almost as good as at present it tends to overshoot.

 

[Staz]

Thanks PJ,

I take your point about accuracy and can see the logic in your reply. I've ordered 2 pid's sensors plus 3 PT100 probes so I think I'll go down the route of a separate heat exchanger and fit one to the HLT and the other to the HE. As I've got a pt100 probe spare and I've bought a digital read out thermometer designed for the probe I was going to fit that as close to the point of entry to the MT as possible so that I can get an accurate view of the recirculated wort's temperature as close to the point of the goods.

That's the plan at the moment but the control box is the first on my 'to do' list and the first few components are turning up in the post ( SWMBO thinks they are Christmas pressies for her :rofl: )

Cheers,
Steve

 

[Staz]

The PID's and relays are here from Auber so build commenced today. First job to was mark out, drill and tap M4 holes and fit the two relays to the heatsink which is now completed.
All the components are now sourced although I'm still waiting delivery on a digital temperature read out and some terminal blocks but I'm going to continue doing as much as I can until they arrive.

THe shiny stuff should be ordered this week and I've sourced an aluminium 8 ltr pot for my heat exchanger and got all the fittings so I'm hoping to have that built next weekend assuming the heating element arrives :grin:

 

[Vossy1]

Staz, where's the piccies :nono: ........honestly you should know by now we like piccies :lol: :thumb:

 

[Staz]

Vossy,
I have failed you

If I tell you my other hobby is photography that would make the sin even worse so lets pretend I didn't say that :pray:

TBH I didn't think anyone would be interested in a photo of two ssr's bolted onto a heatsink and a pile of components....or would they :wha:

 

[shocker]

WHAAAATTTT????? Not interested ?? HERE ?? Thats bloody tech -brew-porn you are talking about ! Wash your mouth out with sodium metabisulphite and get them piccies up !

:clap: :grin: :thumb:

 

[Vossy1]

:lol:

 

[Staz]

Ohhhh Errrrrr. I'd better get the camera out then