Today's Experiment - HLT Stirrer

[John Beere]

I've been debating how to do this for awhile now and everything so far has been overly complex. So today, I decided to just see what would happen if I submerged a cheap aquarium powerhead in 180 degree water - worked perfect. I let it run for over an hour in 180~185 degree water with no noticible loss of power. I think I've found my solution...

 

[billtzk]

That's an interesting solution. Are you planning on installing a HERMS coil, or are you just recirculating to be certain the water is well mixed and you're getting an accurate temp reading?

 

[John Beere]

I have a HERMs coil. You can read more about it here.

 

[RockfordWhite]

Idk if this is a stupid question but, would their be any issue with the pump itself not being food safe?

 

[John Beere]

Well, its probably not "food safe" tested, but it is "aquarium safe" tested - which honestly might have higher restrictions as it must work in a sealed environment. But I'm unsure if the higher temps could effect that or not. I tasted the water afterwards and couldn't taste anything...

 

[The Pol]

I thought of that idea, but figured that if it would work, everyone would be doing it instead of the expensive stuff we (I) come up with. My stirrer was about $100 to build LOL

 

[AiredAle]

John B: I'd check with the pump maker if you can to see if it's made of food grade materials. Personally I'd be nervous about extraction of additives out of the plastic parts at those high temps. The pump may be fine at aquarium temps but could leach lots more out at high temp.

Great idea though, I like simple. I'm looking at using a small cheap March pump I got on eBay for $15 as a circulator. It's got a food grade Kynar pump body so it's good to boiling temps. I'm planning to circulate from the drain back up to a fitting near the top of the HLT that will be angled to create a whirlpool effect.

 

[John Beere]

Yeah, I'm sure it would be completely safe, but I've decided to not be the one to find out and just go with a normal stirrer like The Pol just put together. This is the direction I was heading but I didn't realize the gear motor I bought off eBay was 130v DC - not AC. Damnit. Plus it was WAY bigger than it appeared in the pictures. heh

 

[The Pol]

The gear motors are nice, but one word of CAUTION when buying. Make sure that it is rated for CONTINUOUS DUTY. Most gear motors are not, they are geared because they move valves or things of that nature slowly, periodically, and are not meant for continuous duty. When buying mine I realized that nearly ALL that were made for continuous duty have an integrated fan to cool them. These things still get HOT, even without any resistance on the mixer, they are also sitting above 175F water for hours. If you do not purchase one that is made for continuous duty, you will smoke it, and that sucks, trust me.

EDIT: ALso, do not waste money on a gear motor that turns any slower than 100RPM.. unless you have a HUGE impeller (and room in the HLT for it) it will not mix well. SO, buy one that is at least 100RPM and that is built for continuous duty with a fan to cool it. MCMaster Carr has them for $52 and they are small and powerful!

 

[Grimsawyer]

I have had aquariums in the past. most of my past... Finally got rid of my last 55 gallon tank about a month ago... the rubber on the top and bottom of the impeller might go eventually due to the high temps, plus the power cord is something i'd be weary about, more or less because of the type of plastic it is made of vs. the type that the powerhead is made of. I'm sure the impeller will be mostly fine but some of them the magnet is held to the plastic with glue. Not notched just flat... there are some powerheads that i've found that are inferior but the penguin ones seem to rock! Never had any troubles with them in my tanks. I had a funky powerhead once made, im' sure, from the same material that my foodgrade high temp morebeer march pump head was made out of, that is if memory serves.... I've gone through a few.... anyhow, what brand are ya using? I am curious as to how long it will hang in there too at higher temps! Keep us updated. You could get a cheap powerhead, good quality, that would do a sufficient job for 20-30 bucks... Havn't bought a new one in a few years, maybe i'm out of touch now but seems to be in the ballpark. =D

 

[John Beere]

This was a Mini-Jet 404 - Aquarium Water Pumps & Powerheads: UL-Listed Mini•Jet Pumps

It came free with a 5 gallon bucket of instant ocean... I had a good bit of the cord submerged as well. It was "flexible" at the end of the hour, but seemed completely intact.

 

[John Beere]

I decided to just get a 115v motor like The Pol put on his system... I already had the stirrer. I got the 100 RPM model and it is enough to break the surface tension, but I was hoping for a little more - not that it really matters.

Here is what I put together from a scrap piece of plywood.

And here it is in place running.

 

[The Pol]

Cool dude!