Finding Chaos The Research

Stratification

It's not a question of “if a tank will develop temperature differences at various levels,” but “when, where, 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 purchased and designed, the knowledge base concerning uniform tank temperatures was not up to where we, at Pasco Poly, have advanced it today.

INFRARED COMPLICATIONS

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.

I was puzzled about why infrared thermometers have problems measuring tank temperatures. 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, boundary layers(so called), conduction near the inside wall of the tank, 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.

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.

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

“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 formula include so many variables that any small change in any of them can completely alter the final picture.

“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 and patterns inside a tank, and weather, are made by some of the most notable people in mathematics and weather prediction.

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

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.

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.

Only those who probe each fraction of each region of the interior of each tank and/or apply strong overwhelming external and internal influences, know.

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.

Circa 1986. This was the first 1000 gallon Pasco Poly tank used to test different sizes and styles of cooling columns. Notice the thermometers at different levels and different quarters to help identify convection and temperature differences in different areas of the tank. The cooling column outlet is visible on the upper right side.

A very successful cooling panel, still offered today, to encourage vertical convection to prevent stratification of temperatures in poly tanks.

An early advertisement indicating our awareness of problems

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.

How best to deal with stratification in stainless steel tanks.

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.

“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.
Soft, continuous, high volume wine pump or fan.
100% lid and wall insulation.

CHAOS, THE NEW MATH

Why tank temperatures are so unpredictable.

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

The following notes on Chaos in the real world of tank temperatures are not to “just impress the reader with pretty pictures and impressive names” but are about 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.