• Who knows what temperatures really lurk in the depths of your tanks?

• Only those who probe each fraction of the depth of the interior of each tank

• or apply strong, overwhelming external influences.

• Stratification

• It's not a question of “if a tank will develop temperature differences at various levels,” but “when, how, and how much.” Any tank which is not perfectly and 100% insulated will, in time, develop temperature differences at various locations, depending on chaotic external influences of the particular environment and internal reactions in time spans of even minutes.

• It is not a matter of “WILL it be different?”, but “HOW different?”, and “What will it be hours from now?”

• Old technology

• Inadequate cooling systems are a problem many have been forced into by economic decisions of the past. At the time the tanks were purchase and designed, the knowledge base concerning uniform tank temperatures was not up to where we at PolyVin have advanced it today.

Why tank temperatures are so unpredictable

• CHAOS, THE NEW MATH.

  The following notes on Chaos in the real world of tank temperatures are not just to impress the reader with pretty pictures and impressive names but is the real world of weather systems in tanks. To help explain the magnitude and existence of the tank temperature problem I beg your patience for just a moment to introduce “chaos” in more of a scientific context.

  Chaos helps establish the non-predictability of temperatures at various locations in the liquid inside a tank.

“Chaos” is not just a another modern day buzz word. Chaos and fractals are part of the most complicated type of real mathematics known today. It does refer to what appears to be, in the classic sense of the word, “utter Chaos.” But in fact these formulas include so many variables that any small change in any of them can completely alter the final picture.

In the excellent book on chaos James Gleick tells of Edward Lorenz, a father of Chaos and fractals and of his study of the temperatures in a container on top of a cook stove. He described the total unpredictability of the temperatures in various location in the container, and how they helped him form the theory of "The Butterfly Affect". He described it as a butterfly flapping its wings in China changing the course of a tornado in Kansas.


On the left is an overall plot of the famous mandelbrot set of fractal equations. On the right is an exploded view of a small section of the same plot. Modern powerful computers continue expanding sections of the expanded section showing the extreme complexity that these equations exhibit.

• “The most passionate advocates of the new science go so far as to say that twentieth-century science will be remembered for just three things: relativity, quantum mechanics, and chaos. Chaos they contend has become the century's third great revolution in the physical sciences.” James Gleick

• Harold Agnew, an associate of J. Robert Oppenheimer, helped man the monitoring instruments in the air craft accompanying the Enola Gay over Hiroshima. While at Los Alamos he challenged Mitchell Feigenbaum, another early fluid mechanics and weather predictor, to solve laser fusion, showing his respect of Feigenbaum. These were not just “run of the mill” scientists. They were applying themselves to big puzzles of the early post war period, including weather, convection currents in fluids and air. During World War II, because of the long range aircraft and their dependence on the weather Feigenbaum believed weather forecasting could be reduced to a combination of equations. In the 50s a French mathematician physicist made a disputatious claim that convective turbulence in fluids might have something to do with chaotic behavior, that only very small changes in initial conditions have gigantic affects in the end. Feigenbaum began CIA funded weather studies at Los Alamos and began looking for chaos everywhere. In the 1960s the very earliest powerful analog computers were used to model the weather, and added some clues to the complexity of the problem while chaos (the mathematics ) was begun and the term the “butterfly effect” was introduced. In the 70s Edward Lorenz did the break-through studies beginning with a pan of water on a stove top, and proposals based on fluid and gas convection. In the 80s Von Neuman used the Cray computers to try to predict the weather, still with no success.

• The point is that all of these war time and post war geniuses were bumping shoulders and were greatly puzzled by the convection currents in liquids and air. They proved that one cannot predict the temperature's speed or direction of movement in a tank at various locations without over-coming the small initial conditions with massive protection and/or uniform influences of their own. The close tie between temperatures' patterns inside a tank, and weather, are made by some of the most notable people in mathematics and weather prediction.

  Whether storing, or fermenting long-term or short-term,

  temperature is unknown and very unpredictable in most tanks not fully jacketed.

In studying the temperatures inside tanks, I discovered the likeness of the flow in tanks due to outside temp influences, to weather systems. It genuinely is a chaotic picture inside that mass because of the many influences from outside each individual tank.

circa 1986. This is a picture of a 1000 gal. poly tank wrapped in bubble wrap to permit colder internal temperatures and a rough stainless steel research tank built with a 30 percent liquid jacket and many temperature probes to identify the characteristics of a conventional stainless steel liquid cooled tank. It was a giant surprise to find its poor performance! After testing the poly tank I felt it was marginal until I saw the problem with stainless steel.

Circa 1987. This is the convection aid we developed for solving the problem of stratification. It is a 30 to 100 rpm fan, turning in the wine at a very low power, mounted from the top of the tank.

INFRARED COMPLICATIONS

I was puzzled about why infrared thermometers have problems measuring tank temps. It turns out to be quite complicated and near impossible to get useful temperature information from the wall of a tank. The liquid convection currents and conduction near the inside wall of the tank, and multiple and chaotic air convection and infrared reflections on the outside, make tank wall temps next to useless.

Reflections and Influences

Because we are dealing with infrared, we are dealing with the properties of light and its influence on the infrared thermometer, which measures the brightness of the infrared light emitted or reflected from an object.

• 
  An early advertisement indicating our awareness of problems

  random reflections cause errors

• any thing within sight of the particular point is being looked at by the thermometer and averaged with odd priorities.

• tank shape affects the reflections

• convex shape broadens the field of influences on the thermometer.

• shape and nature of adjacent structures also affect the amount of infrared light reflected on the meter.

• location of other tanks affect it

• direct sunlight is an obvious big source of IR.

• 
  Another early advertisement indicating my early knowledge of and solution to the stratification problem.

  Windows and what is outside of them.

• Un-insulated walls and what is outside of them. They are translucent to infrared.

• warm or cold bodies nearby

• boilers or equipment

SOLUTION TO REFLECTIONS OF IR PROBE

The solution to the reflections was to shield the infrared thermometer (infrared light gauge) from influences other than the object we were measuring. A special cone covering the area being observed by the gauge eliminated the reflections and left the gauge calibration intact.

SURPRISE SURPRISE !

• During the investigation I found the temperature at the wall surface, inside the tank (the boundary layer), was quite different from the temperatures of the interior of the tank. I am convinced that outside surface temperature information is not useful for accurately analyzing the temperature of a tank's contents.

NON INFRARED INFLUENCES

• “pumping over” tends to break up stratification, but the discontinuous nature leaves the tank to the influences of chaos in between pumping.

• air currents are second in powerful influences on the tank, next to direct sunlight.

• open doors

• fans or equipment

• liquid jacket placement

• Jacket placement is just a stab at defeating chaos. There will always be conditions in which a partial jacket will only worsen a temperature difference between different levels in a tank.

• Even 100 percent jacketed wall coverage is barely acceptable when it comes to preventing temperature stratification.

• In some cases only a small amount of inner tank re-circulation is needed to prevent hot spots on the top. But much, much less is needed in a full wall jacketed tank.

The Fix

Re-circulating Air Jacket

PATENT PENDING

I would like to propose a fix for your un-jacketed and poorly jacketed tanks. We performed tests and analyses on stainless steel tanks in various configurations of cooling to confirm my analysis.

As the result of these tests I can also propose very effective upgrades for your poorly cooled tanks and make the least favorite tanks into favorite ones.

By examining the data from a 2700 gallon research tank and the 500 gallon liquid cooled test tank along with many, many other test runs, I present the following proposals

REJACKET™ - Biggest bang for the buck.

Re-jacket configuration retrofitted to a salvaged tank.

• Do not need to add controls or refrigeration, just add a jacket and blower.

• Includes an insulated cold air jacket and vanes, and cold air re-circulation system, to utilize the existing cooling capacity of the tank and remote liquid chiller.

• Retrofit KiLR-CHiLR™ (using existing cold glycol )

TESTING THE FIX

THE REJACKET™ TESTS

This is the 500 gallon salvaged tank we put a crude liquid jacket on to perform tests of the "re-jacket" configuration.

This was inserted into the KiLR-CHiLR™ shell to re-circulate the air properly while cold water was pumped through the jacketed

It was a very successful and informative test.

• SURPRISE SURPRISE AGAIN!

• I was surprised by the results! I felt that putting a re-circulating air jacket on an existing 25 or 30 percent wall coverage liquid jacket would just double the effect of the liquid jacket because of the utilization of the jacket's external area to effectively double the cooling surface. As it turned out, it appears to have much more than doubled the effect. There was a phenomenal increase in cooling rate and uniformity because of the additional convection set up at all levels of the tank. It created a larger current flow in the jacket area, increasing heat exchange and allowing it to involve the whole tank . It was more chaotic than the non-liquid jacketed tank using refrigerated air only, but it was fast and eventually stabilized into a good uniform, non-stratified tank. However, it is quite sensitive to how full the tank is, relative to where the location of the liquid jacket, whereas the chilled air model works at any level.

KiLR-CHiLR™

The best overall system

1500 gallon Real fermenter KiLR-CHiLR™

Better Control

-heat or cool

-automatic temp control

-fill to any depth

-go to freezing temperatures

-minimum stratification

-summer or winter

• Efficiency

  -freon system is not up and running when cooling not required

  -does not warm or remove moisture from environment

  -insulated outer shell prevents warming or cooling from outside influences

• Cost

  --no cost of future capacity of central glycol system needed.

  --less cost than fully jacketed glycol system

• Versatility

• Add a cold air chiller, jacket to existing stainless steel non-jacketed tanks

--does not change the environment of the room after temperature is reached.

--heat or cool

--freon or glycol

--freon allows moving without dragging along the plumbing

--use existing jacket and controls from existing tank

ACCESSORIES

• TANK TEMPERATURE PROFILER

• profiles the temperature of the tank and logs it

• logs and plots the tank temperatures at each inch for long periods

• CONVECTION AIDE

• Slow, positive circulation of tank contents breaks up stratification generated during tank warming operations and stubborn instances of questionable conditions.

• Fermentation differences at different levels in the tank?

  As temperatures rise at the walls and top of the tank, the less dense hot liquid rises to the top with a strong tendency to build a hot strata there. Any yeast in this hot strata reproduces rapidly and builds heat at the top without causing agitation in the lower part. This leaves the lower part undisturbed and cool, while that yeast in the warmer upper strata begins heating and generating, what I believe to be, geometric heating rates and high gradients in that area resisting control by our slower monitoring and control measures.

• I truly believe that, from the temperatures I have seen at top of tanks, there are times that fermentation can run away in the top part of the tank and die, even in between two jackets, and have very little or no fermentation in the lower parts below the upper jacket.