gregdech
Well-Known Member
As I dove deeper into the wonderful world of all grain homebrewing, I quickly realized that I needed a better way to manage my hot liquor than three pots on the stove! Hence the birth of my electric HLT. My initial hangup to getting this project started was the need for a vessel, since I didn’t have the cash to spring on a large kettle. When I bought my kegging setup from another homebrewer, he threw in all of his other gear (hydrometers, carboys etc.) since he was getting out completely. This gear included an HDPE fermentor with a spigot at the bottom and no lid, which I had set aside since I didn’t really have a use for it. One day I was going thru my gear cleaning up and as I looked at this vessel, the light bulb went off: Electric HLT.
First off, here are the pictures of the electric HLT:
http://electrichlt.shutterfly.com/36
http://electrichlt.shutterfly.com/35
http://electrichlt.shutterfly.com/37
http://electrichlt.shutterfly.com/31
http://electrichlt.shutterfly.com/32
http://electrichlt.shutterfly.com/33
http://electrichlt.shutterfly.com/29
http://electrichlt.shutterfly.com/30
As mentioned, the vessel “was” an HDPE fermentor. I removed the plastic spigot that it came with, enlarged the hole and added a 1/2” ball valve.
There are 2 x 1500W/120V elements mounted at 120 degrees apart (the elements and valve are all equally spaced). The 2 elements are at different heights to prevent contact. Each element was fitted with a custom made copper grounding ring. The elements are sealed using the rubber ring that comes with the elements (on the outside of the vessel) and the threaded fitting on the inside was made by hacking a copper NPT fitting (http://www.mcmaster.com/#5135k23/=19ux7w) and using just the threaded portion. Although the above fitting is a tapered (NPT) thread, the fitting can grab enough threads to get a tight seal. Remember that with the rubber gasket for the element and the thickness of the pot/vessel, you are only using a few threads at best and I found that these fittings were able to grab enough threads to get a tight seal (YMMV). The wired ends of the elements were covered by PVC pipe caps (don’t remember what size I used, 1-1/2” I think) and the cap filled with JB Weld to pot the connections.
Using 2 elements like this requires that you have access to 2 outlets wired to different breakers. Because I use this in my basement, and because all of the wiring is exposed and was done by me, I was able to wire 2 outlets on different circuits, both with GFCI’s.
Because this vessel did not come with a lid, I had to make one. I got a piece of thin stainless steel from Metal supermarkets (http://www.metalsupermarkets.com/, not sure of the grade or thickness, I just asked for the cheapest stainless they had) and made a circle to fit the top lip of the vessel. I covered this stainless with 2” rigid foam (secured using silicone) and added a handle scavenged from a reno project. I drilled a hole in the lid to allow me to mount a temperature probe (18” long custom brass probe for RANCO, see details here https://www.homebrewtalk.com/f51/diy-sensor-probes-ranco-controllers-127463/).
I use both elements to get up to temperature and then I control the temperature in the vessel using my RANCO controller and one of the elements. This seems to work well for my purposes.
I also use this vessel as my boil kettle. To do this, I collect the first runnings and first sparge in an aluminum turkey fryer kettle. Once I have transferred the second (last) sparge to the mash tun, I empty the HLT and pour the contents of the aluminum kettle into the HLT/Boiler, collect the last sparge in the (now) boiler and give ‘er. For the boil, I use both elements full blast for a total of 3000 W of heat input. This gives me a boiloff rate of 3.5 L/hr. Using this data, the heat loss calculations for this kettle are:
Heat loss from steam = (3.5 L/h)(1 kg/L)(2261.7 kJ/kg)
= 7916 kJ/h
= 2.2 kW
Heat loss from kettle = 3 kW – 2.2 kW
= 0.8 kW
Therefore, of the 3 kW of heat I put into the kettle, 0.8 kW is lost from areas other than boiloff. This is just fine for my purposes as I feel 3.5 L/hr (0.9 USgallon/hr) is a reasonable boiloff. These numbers agree reasonably well with the numbers given by “The Pol” whom requires ~3.6 kW to get a reasonable boil for his system. My kettle is 1/8” thick HDPE, which is a much better insulator than the stainless keggle that he uses and so I would expect that he would need a little more heat input to get the same boil.
As for the scorching demon, he has not reared his ugly head in the 5 batches I have done using this as my boiler, and I have done lighter beers which would show scorching if it was present (2 cream ales and a wit). I don't know the watt density of the elements off the top of my head, but they are the standard 1500W/120V elements you would see in most hardware stores (i.e. not low watt density).
Well, I got a little more long winded than I had intended so I will end it here. All in all, I am very happy with how this project turned out and I would recommend it to anyone who likes to build things or who has more time than money. If anyone has any specific questions about how this is built fire away and I’ll do my best to answer them.
Cheers,
Greg
First off, here are the pictures of the electric HLT:
http://electrichlt.shutterfly.com/36
http://electrichlt.shutterfly.com/35
http://electrichlt.shutterfly.com/37
http://electrichlt.shutterfly.com/31
http://electrichlt.shutterfly.com/32
http://electrichlt.shutterfly.com/33
http://electrichlt.shutterfly.com/29
http://electrichlt.shutterfly.com/30
As mentioned, the vessel “was” an HDPE fermentor. I removed the plastic spigot that it came with, enlarged the hole and added a 1/2” ball valve.
There are 2 x 1500W/120V elements mounted at 120 degrees apart (the elements and valve are all equally spaced). The 2 elements are at different heights to prevent contact. Each element was fitted with a custom made copper grounding ring. The elements are sealed using the rubber ring that comes with the elements (on the outside of the vessel) and the threaded fitting on the inside was made by hacking a copper NPT fitting (http://www.mcmaster.com/#5135k23/=19ux7w) and using just the threaded portion. Although the above fitting is a tapered (NPT) thread, the fitting can grab enough threads to get a tight seal. Remember that with the rubber gasket for the element and the thickness of the pot/vessel, you are only using a few threads at best and I found that these fittings were able to grab enough threads to get a tight seal (YMMV). The wired ends of the elements were covered by PVC pipe caps (don’t remember what size I used, 1-1/2” I think) and the cap filled with JB Weld to pot the connections.
Using 2 elements like this requires that you have access to 2 outlets wired to different breakers. Because I use this in my basement, and because all of the wiring is exposed and was done by me, I was able to wire 2 outlets on different circuits, both with GFCI’s.
Because this vessel did not come with a lid, I had to make one. I got a piece of thin stainless steel from Metal supermarkets (http://www.metalsupermarkets.com/, not sure of the grade or thickness, I just asked for the cheapest stainless they had) and made a circle to fit the top lip of the vessel. I covered this stainless with 2” rigid foam (secured using silicone) and added a handle scavenged from a reno project. I drilled a hole in the lid to allow me to mount a temperature probe (18” long custom brass probe for RANCO, see details here https://www.homebrewtalk.com/f51/diy-sensor-probes-ranco-controllers-127463/).
I use both elements to get up to temperature and then I control the temperature in the vessel using my RANCO controller and one of the elements. This seems to work well for my purposes.
I also use this vessel as my boil kettle. To do this, I collect the first runnings and first sparge in an aluminum turkey fryer kettle. Once I have transferred the second (last) sparge to the mash tun, I empty the HLT and pour the contents of the aluminum kettle into the HLT/Boiler, collect the last sparge in the (now) boiler and give ‘er. For the boil, I use both elements full blast for a total of 3000 W of heat input. This gives me a boiloff rate of 3.5 L/hr. Using this data, the heat loss calculations for this kettle are:
Heat loss from steam = (3.5 L/h)(1 kg/L)(2261.7 kJ/kg)
= 7916 kJ/h
= 2.2 kW
Heat loss from kettle = 3 kW – 2.2 kW
= 0.8 kW
Therefore, of the 3 kW of heat I put into the kettle, 0.8 kW is lost from areas other than boiloff. This is just fine for my purposes as I feel 3.5 L/hr (0.9 USgallon/hr) is a reasonable boiloff. These numbers agree reasonably well with the numbers given by “The Pol” whom requires ~3.6 kW to get a reasonable boil for his system. My kettle is 1/8” thick HDPE, which is a much better insulator than the stainless keggle that he uses and so I would expect that he would need a little more heat input to get the same boil.
As for the scorching demon, he has not reared his ugly head in the 5 batches I have done using this as my boiler, and I have done lighter beers which would show scorching if it was present (2 cream ales and a wit). I don't know the watt density of the elements off the top of my head, but they are the standard 1500W/120V elements you would see in most hardware stores (i.e. not low watt density).
Well, I got a little more long winded than I had intended so I will end it here. All in all, I am very happy with how this project turned out and I would recommend it to anyone who likes to build things or who has more time than money. If anyone has any specific questions about how this is built fire away and I’ll do my best to answer them.
Cheers,
Greg
