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One or Two Heating Elements?

Posted: Sun Dec 16, 2018 9:41 am
by Old Man Bakke
I need to decide whether to use a single electric 5500W heating element OR two 2500W-3000W heating elements. I have heard that 2 elements could be potentially better with heat density. Additionally I am concerned with scorching upon initial heating up.

My plan as it stands now is to come in the bottom of a keg, horizontally, with some type of element. If I was to use 2 elements, I am considering coming from 90 degrees opposite the other element; thus creating like a cross inside the keg. OR!, coming in from the bottom of a keg and annealing the elements with a torch and bending them to a horizontal position when placed in the keg from a bottom penetration.

Just looking for some insight from the community....thanks

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 12:11 pm
by acfixer69
Well im going to assume your talking about a 15.5 gal keg. I run 2 elements at 90s offset. Both are 5500 watt uld elements one on a switch the other is on the controller. Scorching is not a problem. I run my wash dirty. I would not put them in from the bottom as there is nothing to gain from that and that is better left for a drain.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:09 pm
by NZChris
With two, blowing an element during a run isn't a disaster as you can finish the run on the other element.

I have bent the elements in my still, having inserted them through the bottom to keep them low to enable me to run quite small charges.

Scorching requires that you have something like starch in the wash, or running dry.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:18 pm
by zed255
I like my 2x 3000W setup. As NZChris mentioned there is redundancy on the off chance one element fails. I also find using a controller and either one or both elements allows for fine control of input heat.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:33 pm
by Old Man Bakke
acfixer69 wrote:Well im going to assume your talking about a 15.5 gal keg. I run 2 elements at 90s offset. Both are 5500 watt uld elements one on a switch the other is on the controller. Scorching is not a problem. I run my wash dirty. I would not put them in from the bottom as there is nothing to gain from that and that is better left for a drain.
Yes a 15 gal keg! If i was to enter throguht the bottom i would make 2 additional penetrations for the units. But thanks for the input, really apprectiate it!

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:35 pm
by Old Man Bakke
NZChris wrote:With two, blowing an element during a run isn't a disaster as you can finish the run on the other element.

I have bent the elements in my still, having inserted them through the bottom to keep them low to enable me to run quite small charges.

Scorching requires that you have something like starch in the wash, or running dry.

I am very curious to how to go about bending the elements. Did you just use a propane or Mapp gas torch? How easy was it? Where did you penetrate the keg at / how to the elements sit/oriented inside the keg?

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:54 pm
by bluefish_dist
I just beat on them with a hammer to bend them. Had a few of the wave style that wouldn’t fit. Just hit them a few times until they were straighter. Wood blocks were used to prevent damaging the metal.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 1:55 pm
by acfixer69
Bending the element with hands is all thats required just do it softly and angle of bend radius greater then radius of 2 thumbs.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 2:31 pm
by acfixer69
bluefish_dist wrote:I just beat on them with a hammer to bend them. Had a few of the wave style that wouldn’t fit. Just hit them a few times until they were straighter. Wood blocks were used to prevent damaging the metal.
What are they heaters from hell. Never in my 40 years at heating shit have i heard of that.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 2:44 pm
by OtisT
I’m curious, are you planning to use a controller on one or both if you use two? Also, is this a pot or fractioning column and if the latter, what is the column diameter? Otis

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 5:05 pm
by Old Man Bakke
acfixer69 wrote:Bending the element with hands is all thats required just do it softly and angle of bend radius greater then radius of 2 thumbs.
Ha! Sounds too good to be true. Like a Carny Trick / Strong Man show [FACE WITH TEARS OF JOY]

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 5:12 pm
by Old Man Bakke
OtisT wrote:I’m curious, are you planning to use a controller on one or both if you use two? Also, is this a pot or fractioning column and if the latter, what is the column diameter? Otis
Haven’t figured controlling the unit(s) out yet. Not a big concern of mine yet. Could do one heater controlled, one heater just on and off and one controlled OR both controlled. Not sure yet. Haven’t figured out the advantage of the two different control options yet.

Column diameter will be 2”. Will probably just begin my novice distilling days as a pot still with the potential of a more advanced column. As the keg sits now I have a 6” ferrule reduces to a 2” tri clamp.

Re: One or Two Heating Elements?

Posted: Sun Dec 16, 2018 7:28 pm
by DetroitDIY
I run the same as ACFixer, except I wasn't smart enough to position mine perpendicular. Thought about that after I had had the two flanges welded on... next time. All that said, I've never yet run my still at more than 5.5 kW. Not really sure when I would actually want more power, but I'm set to run it if I ever do.

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 6:26 am
by shadylane
I like having two 4500w elements. On heat up, both run on full power.
For distilling one runs on full power and the other on 120v.
The controller seldom gets used anymore.
My attempts at bending electrical heaters haven't worked very well.
After a couple runs the elements failed.
On a side note, my heaters are from the same manufacturer but one is significantly more powerful than the other.

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 9:15 am
by bluefish_dist
You only need one variable control circuit. The 2nd can be a relay on a switch. I run 3 elements on my big still, one variable, 2 switched on relays. That allows power from 0 to full power for the least cost. Use both to warm up, then if you need from 50-100% power just turn down one element, the other at full power, if from 0-50%, turn one off and vary the one element.

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 9:45 am
by HDNB
shadylane wrote:I like having two 4500w elements. On heat up, both run on full power.
For distilling one runs on full power and the other on 120v.
The controller seldom gets used anymore.
My attempts at bending electrical heaters haven't worked very well.
After a couple runs the elements failed.
On a side note, my heaters are from the same manufacturer but one is significantly more powerful than the other.
for curiosity sake, have you ever measured the resistance?

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 10:24 am
by OtisT
Old Man Bakke wrote:
OtisT wrote:I’m curious, are you planning to use a controller on one or both if you use two? Also, is this a pot or fractioning column and if the latter, what is the column diameter? Otis
Haven’t figured controlling the unit(s) out yet. Not a big concern of mine yet. Could do one heater controlled, one heater just on and off and one controlled OR both controlled. Not sure yet. Haven’t figured out the advantage of the two different control options yet.

Column diameter will be 2”. Will probably just begin my novice distilling days as a pot still with the potential of a more advanced column. As the keg sits now I have a 6” ferrule reduces to a 2” tri clamp.
File this under “just my opinion”.

With the pot, you could go with two elements, both w/o a controller, and be happy. When you get to fractioning, you will want a controller for at least one element. I see no need for having both controlled. I would personally recommend you stick with one controlled high power element (4000-5500w) and use any other ports on your boiler for a Drain and Thermowell (Thermowell is for mashing, not stilling).

Why you want a controller for fractioning. You can only apply so much power before flooding the column and loosing your fractioning potential. To get the fastest takeoff rate possible while still maintaining a max ABV, you need to find and run your still at this max operational power level. You need a controller (or a lot of luck) to tune your still to this specific power level.

I have read on HD and also experienced myself, that to get max ABV in a packed column you need to limit vapor speed to 20 inches/sec. In a 2” column it takes 1500w to reach 20”/s. 3100 watts for a 3” column, and around 6000w for a 4” column. So if you build a 2” column, you would only need a 2000w controlled element to fraction at max speed, though you will appreciate more power to bring things up to temp faster.

Otis

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 11:31 am
by NZChris
With two elements you have the option of wiring them in series, which gives you quarter of the watts of both elements combined. This can be useful if you blow your controller mid run, or don't need one for a run. It also gives you a very low watt density if you need it.

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 3:16 pm
by Kareltje
I was planning to say more or less what NZChris just said.
I inherited a boiler with a 2.3 and a 3.2 kW element. So parallel they give me 5.5 kW (I connect them to different groups).
Separte I have either 3.2 or 2.3 kW and in series I have about 0.9 kW.
I must admit that I make constructions that are not really allowed.

Re: One or Two Heating Elements?

Posted: Mon Dec 17, 2018 4:12 pm
by shadylane
HDNB wrote:
shadylane wrote:I like having two 4500w elements. On heat up, both run on full power.
For distilling one runs on full power and the other on 120v.
The controller seldom gets used anymore.
My attempts at bending electrical heaters haven't worked very well.
After a couple runs the elements failed.
On a side note, my heaters are from the same manufacturer but one is significantly more powerful than the other.
for curiosity sake, have you ever measured the resistance?
If I remember correctly one element was around 13 ohms and the other a half ohm lower

Re: One or Two Heating Elements?

Posted: Sat Dec 22, 2018 10:57 am
by Old Man Bakke
Thanks everyone. I am going with 2 elements

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 2:05 pm
by Old Man Bakke
acfixer69 wrote:Well im going to assume your talking about a 15.5 gal keg. I run 2 elements at 90s offset. Both are 5500 watt uld elements one on a switch the other is on the controller. Scorching is not a problem. I run my wash dirty. I would not put them in from the bottom as there is nothing to gain from that and that is better left for a drain.
Having your elements 90deg opposite of eachother...do you have them at different elevations so as to not touch. I am concerned that having them ovelap in close proximity of one another would create a hot spot!?

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 2:21 pm
by shadylane
My elements are at 90' and about 2 inches apart
Other than my screw-ups, I haven't had a problem yet

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 2:28 pm
by DetroitDIY
Mine are about 1/2 inch off in elevation... mostly just enough to facilitate installation without them colliding with one another. Mine are the serpentine shape with tri-clamp flanges, so they're a little tricky getting in. I wanted both of mine low so that I could run with partial washes. Even going as low as I did, I need like 5-ish gallons to be comfortable that thye'll stay submerged.

There will be a slightly hotter spot at the intersection in terms of heat flux into the wash, and colder spots as you move away from the heating elements, but as things heat up, the convection will pick up and you should not be a greater risk of scorching than with a single element. You just don't want them so close that they're difficult to install, or that they may touch. Touching MAY not be an issue, or it may create a little spot to trap fluid flow, any sediment, etc. and lead to a greater risk of scorching.

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 3:13 pm
by Old Man Bakke
cool thanks guys!

BTW where is everyone buying their ULWD Camco elements at? I see people stating "mine were just $8" or something like that. I can only seem to find ULWD in the 20-30$ range. I was looking for something like 3000W at 240V or maybe even 2500W/240V screw in 1" NPS types

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 4:31 pm
by shadylane
I get my stuff on Amazon
https://www.amazon.com/Camco-02493-Scre ... o+elements" onclick="window.open(this.href);return false;" rel="nofollow

https://www.amazon.com/Camco-02523-Scre ... tt+Density" onclick="window.open(this.href);return false;" rel="nofollow

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 4:54 pm
by DetroitDIY
Here's what I'm using: https://www.amazon.com/gp/product/B01MT ... UTF8&psc=1" onclick="window.open(this.href);return false;" rel="nofollow

It's not advertised as the Ultra Low Watt Density, but I've never had any trouble.

I've read about this ULWD, but honestly I don't get it. Watts are energy per time. So for using a similar wattage heater (5.5 kW in my case), and assuming that the heater lengths (and surface area o the heaters) are the same between "conventional" and ULWD, then the average watts per unit length should be the same. I'm guessing that while the average is the same between conventional and ULWD, the distribution must be more even in the ULWD design (a more uniform heat flux between any two given unit length of the heater element), whereas the conventional one may have more difference between the hottest and coldest portions. So... peak heat flux per unit length may be slightly higher in a conventional design.

Does anyone know if this is correct for the ULWD vs conventional heaters? Is there something I'm missing? Given I've never scorched a wash yet, I'm not inclined to change. Perhaps I'll change my tune when I get into all grain washes??

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 5:35 pm
by Old Man Bakke
ok, good! I was starting to think that not everyone was using the ULWD /Stainless Steel expensive types.

I like seeing what people are actually purchasing and using! Thanks fellas !

DetroitDIY- Watts are just Amps x Voltage (P=IxE). I was thinking the same thing: if the lengths are the same then wouldn't the density be the same at the same voltage!?

Re: One or Two Heating Elements?

Posted: Sun Jan 06, 2019 5:51 pm
by DetroitDIY
Yes, watts are the same between the conventional and ULWD, so I figure density is just referring to the watts per unit length, in other words, the uniformity of the heat distribution along the length of the element. Can't figure our any other meaningful interpretation... could be just a gimmick. I'm reasonably familiar with the physics equations and engineering. Thanks Old Man... good luck with the heating system. :thumbup:

Re: One or Two Heating Elements?

Posted: Mon Jan 07, 2019 6:04 am
by bluefish_dist
The ulwd are longer and there is even a watt per area difference between the straight ones and the curved ones. Personally I started with a non stainless type and quickly changed to the stainless ones that run about $40 as they don’t rust.