Upgrading HLT element question

[Ditchnbeer]

Hi,

I am happy with my AG system except ramp times are slower than ideal. I have a 2400W element heating approx. 42 litres in my HLT, which also has my HERMs coil installed inside it. I want to increase my ramp times by either replacing the current element or adding another one.

Has anyone done any research into what is better - having 2 x 2400W elements or 1 x 4500W ?

(My SSR and electronic controller panel can handle the increase in current or be easily modified to do so).

 

[barls]

is this being run on 15 amp or 10.

 

[mofox1]

Well, 2x 2400 is more than 4500, so I would hope it ramps faster.

However, assuming you have at least a 20a supply and your switching controls can already handle this, it would be a no brainer for me - I'd swap out the element for the higher power one. Only one thing to change means only one chance of stuffing something up. No more holes to punch, no more switches to wire up...

I've got the 5500w element in my HLT (contains coil like yours). HLT will ramp by more than 1deg/min with 60L. The 4500 would probably get you the same ramp with your smaller volume.

 

[Adr_0]

A nice, simple rule if you know your volume and your desired ramp time:
[Water volume (L) x 4180J/kg°C x 1°C] / 60s

Which means that I want to hit 1°/min or 1°/60s... or maybe you want to hit it in 30s, or 45s.

Anyway, for 45L to get 1°C/min you would need 3150W theoretically, realistically you should go for a 3600W (next size up). 2400W is ok for 20-30L but yeah won't keep the same ramp rate with volumes more than that

In a HERMS system, there are some other factors to consider though... how big is your mash volume and how long is your coil?

 

[Ditchnbeer]

I only 21L batches so mash in with ~ 20 litres and only sparge with enough to collect 32 litres in kettle. Rest of hot water is used for cleaning.
My current system is 10A but obviously would upgrade it if I add / upgrade element.

Mofox - where did you get the 5500W from?

 

[Ditchnbeer]

My HERMs coil is approx. 5.1m long, 8 coils inside HLT.

 

[Adr_0]

Ok, so 5.1m coil, 45L of water heated and about 25L of mash volume.

What is your ramp time at the moment, and do you get any overshoot? How hot does your HLT get when you ramp to sacch temperatures?

I'm thinking that yeah, an element might help but you might need a lot more coil length, and/or might need to keep the water volume to an absolute minimum and heat up that cleaning water either when you chill you wort, or if you no chill, in parallel with boiling.

 

[Ditchnbeer]

I haven't measured exactly but it may be 1 degree every 2.5 minutes, very slow to rise 10 degrees (say from 55 to 67). My HLT is usually a few degrees about target but haven't measured.
I never get overshoot, my PID does a good job, been auto tuned and happy with its operation, as I stated the only issue I have is slow ramp times.
Thx for yr help.

 

[trevgale]

I got some good stainless 3000W and 3600W elements from online brewing supplies for my HLT and HEX. I am using a 4500W ULWD camco element I got from Amazon in my kettle, although they are not stainless and can rust a little at the base. I did however notice recently that the Electric Brewery are selling a version of the 4500W and 5500W Camco ULWD elements with a stainless base, If I ever need a replacement I'll probably grab one.

 

[Adr_0]

That's cool - sounds good, and as you said, PID has done a good job.

You might benefit from extra coil length, e.g. 10m, rather than needing to go a bigger element. If you can fit 10m in there for example you will see a much better ramp rate because more power from the element is going into your wort rather than just the hot water.

 

[Adr_0]

Just a quick one... are you controlling your element from temperature in the HLT or wort in the coil back to the MLT?

 

[mofox1]

I only 21L batches so mash in with ~ 20 litres and only sparge with enough to collect 32 litres in kettle. Rest of hot water is used for cleaning.
My current system is 10A but obviously would upgrade it if I add / upgrade element.

Mofox - where did you get the 5500W from?

Camco brand from amazon, was around us$25 when I got it. As others have mentioned, the base can rust up a bit but as far as I can tell it doesn't impact the finished product at all.

If you don't mind parting with closer to $100 then you can pick up stainless steel base versions from a few places.

 

[trevgale]

Here are the stainless versions of the camco elements:

http://www.theelectricbrewery.com/stainless-steel-heating-elements

About $40 US plus postage.

 

[Ditchnbeer]

Just a quick one... are you controlling your element from temperature in the HLT or wort in the coil back to the MLT?

I have my temp probe on the outlet of the coil as it goes back to my MT.
Thx for suggestions all.

 

[Adr_0]

Do you have any interest in improving mash ramp times, or are you mostly interested in improving HLT ramp times?

 

[Ditchnbeer]

It would be mash ramp times, like my wheat one uses 43,62,70 then 77. It takes ages to get from 43 to 62.

 

[Adr_0]

If you want to help mash ramp times, you will need more length in your coil,eg 10-15m. Thin means that the heat you put in from your element gets through to the circulating wort.

As an example, if you go from 5m to 10m, you get 84% more power into your wort. This means it goes into your wort rather than the hot water.

Going to 4500W and a high current circuit is a big job. Considering you only do single batch, is it worth trying out a 10-15m coil with your existing 2400W element?

 

[Adr_0]

To illustrate, if you are getting 1°/2.5min...

(25kg mash x 3950J/kg) / (60s x 2.5min) = 658W,even though you are using a 2400W element.

If you double the length you can theoretically get 1.84 x 658W, or reduce your ramp time to 80-90s per degree.

 

[Ditchnbeer]

Well Adr_0 its awesome advice and logic you have provided. I will proceed with re-making my coil (my plumber mate has been difficult to get here lately so will be a long time project) and probably also upgrade the element (as I can easily [I'm a sparky] and electronics & SSR have enough capacity for 25A) but don't need to go huge accordingly to yr calculations. Maybe a 3600W and longer coil will do the trick.
Thx again

 

[MastersBrewery]

Simpler and more versatile would be to grab an over the side element, used on a sepetate circuit and only when ramping