Immersion chiller design: controlling the flow of the wort for efficiency

[ldave]

I use a counterflow chiller in my operation but I had this idea for a more efficient 'self flowing' (on the wort side) immersion chiller. Instead of a simple helix, it's a helical formed into a cone shape, pointy end up. This shape should present coil surface area in a parallel wort flow pattern across the coil instead of the series flow pattern inherent in a simple helix. In a simple helix, cooled wort flows downward from the topmost coil, bathing the lower coils in cooled wort, diminishing their exposure to hot wort, lowering their deltaT, lowering their efficiency. This design mitigates that effect. Each coils downward convective wort flow is not interfered with by any lower coils. All coils 'see' fresh hot wort flow. Maximum flow. Maximum efficiency. Maximum downward convective flow should be from the top innermost coil, closest to coil input, coldest coolant, largest deltaT, and, remembering that buoyancy (in this case, sort of 'anti-buoyancy') causes not just an increase in velocity but an acceleration (increasing velocity with distance), the longer cold flow distance means stronger flow. See attached .pdf for diagram. Note that the coil is perched on stand-offs that would allow flow outwards and underneath the bottommost coil, 'sweeping the corners' as it were, outwards then upwards. Could be hung, too. So, the largest coil should be somewhat smaller than pot diameter and poised up off the vessel bottom.

I've researched the lit and included the 2013 sci paper 'Heat transfer analysis of cone shaped helical coil heat exchanger' here, as well. Note that their dataset only goes up to 270 L/hr. That's 1.2 gallon/min. And they're showing about 1.5 times the performance of the simple helical coil at that flow rate. It must really self-flow like a bad-ass.

I'll never build it for myself. But one of us geeks might.

View attachment Inverted Conical Helical Immersion Chiller.pdf

View attachment 2013-Heat transfer analysis of cone shaped helical coil heat exchanger.pdf

 

[stpug]

The King Cobra by Jaded Brewing has that inverted-cone design. In addition, they basically stack three small-diameter, inverted-cones on top of each other for more cooling. Usage also includes the recommendation to manually stir/agitate/move the chiller in your wort as it's cooling to keep it in contact with the hot wort as much as possible.

 

[ldave]

There would be this design (see .pdf), also: the 'non-inverted' cone, pointy end down, stood off the vessel bottom. I would think that this design would more effectively collect the precipitating solids on the center of the vessel bottom (where I like them), 'sweeping the corners' as it were, from outwards to inwards.

I like the idea of stacking conical helicals. Double or triple the surface area while keeping wort 'series flow' to a minimum. This is key concept to realising the greater performance of parallel flow heat exchanger design.

Can't be such a bad idea if it's for sale somewhere, can it?

Thanks for info.

View attachment Conical Helical Immersion Chiller.pdf

 

[stpug]

I think it's an excellent idea - failed to mention that in previous post. I've looked into making this myself (king cobra style). Just have a few other beer-related projects to finish up before going down this path.