Heat Exchanger

[Oregon Spirit Distillers]

I am looking to purchase/have fabricated a heat exchanger to extract the heat from our stillage and preheat our next run.

We mash, ferment, distill grain in so our stillage can be pretty thick.

Our still is 400 liters.

Any thoughts?

Thanks,

Brad Irwin

Oregon Spirit Distillers

541.382.0002

[ViolentBlue]

a nice 2" copper tube looped twice in your Preheat vat would transfer a lot of heat and would be easy enough to pump your spent mash through, just be sure there are no kinks or obstructions for the grain to gather.

[nick jones]

I'm in the process of dealing with the same issue, so while I don't have any solid answers for you, I'll let you know some of the considerations I've been mulling over in the hope that you find them helpful in your own project. Also, there are some great previous threads on the subject.

Since I'm mostly looking to heat up lautered wash, I'm thinking that a plate HEX will work for me. But if, like you, I was thinking of mostly running mash, I'd tend to think a tube-in-tube would be the way to go.

I tend to agree with the school of thought that a wash preheater (a holding tank where the vapor of your distillate heats your next charge) causes more problems than it solves (though many people make great spirit using a wash preheater, not the least of which is cognac). But if you're more of the French school of thought, I'd say that rigging up a system to condense some of your spirit using your next charge would be a very good way to go. With mash, you'd probably need to agitate it, though (unless you slowly passed the mash through a shell around the vapor pipe and into an insulated holding tank, or something like that. Hmmmm...)

Depending on the design flow rate of your HEX, you could be adding significant time between batches to pre-heat your wash using stillage, while already having it hot from a wash preheater means that the only restricting factor is how quickly you can empty and refill your still. Plus, you'll save on water usage. I'm thinking of approaching this problem from a different angle:

Since I also don't want to gook up the service side of my HEX with stillage (it seems like it would be a nightmare to keep clean running wash through both sides) I'm starting to think that I'll pull water from my hot liquor tank (which has all of the heat we pull out of our condenser) to heat up my next charge, and find a plate HEX capable of dropping the hot liquor temperature to a point where I can re-introduce it to my cold liquor tank and reuse it through my condenser - my water usage would go WAY down, and that's a big deal for us in the desert. Plus, I don't have to worry about cleaning the service side of my HEX nearly as often, since all it ever sees is clean water. And since I can drain my still almost instantly, I can start filling it without having to worry about taking the additional time to drain the stillage through a HEX.

Hope these considerations help,

Nick