Where do we go
Where do we go
Where do we go from here?

("Where Do We Go From Here," by Chicago, 1970)

Knowing where you're going shortens the trip.

The next PTOA Focus Study Area builds upon what PTOA Readers and Students have learned regarding the Process Variable Temperature, Process Industry Schematics (P&IDs), and Process Industry Automation.

 

INTRODUCTION TO
TEMPERATURE-CHANGING EQUIPMENT

The next series of PTOA segments introduce temperature-changing equipment typically found in process industries.

The purpose of some temperature-changing equipment is to increase the process stream temperature.

A Fired Heater (in the picture on the left) is incorporated into a process when it is absolutely necessary to make certain that a target process temperature is reached; if the target process temperature is not reached the next processing step will be unsuccessful and the final product will be inferior and probably useless.

Some temperature-changing equipment decreases the process stream temperature.

The bank of Cooling Water Towers in the picture on the right generates the utility called "cooling water."

Cooling water is distributed throughout the process facility wherever it is needed to cool down process stream temperatures.

PTOA Readers and Students that take a closer look at the Cooling Tower photo will see the heat removed from the process streams; the heat has been transformed into a vapor that is rising above the Cooling Towers.

One piece of temperature-changing equipment increases and decreases process temperatures at the same time.

PTOA Readers and Students have already been introduced to this equipment: the Shell and Tube Heat Exchanger.

 

CHANGING PROCESS TEMPERATURES INDIRECTLY

None of the temperature-changing equipment shown above ever directly mixes the process stream with the heat-up or cool-down source. The temperature-changing done in temperature-changing equipment is accomplished indirectly.

If the process stream were allowed to mix with the heat source or cooling source, the purity of the final product customers want to pay for would be in jeopardy.

All the process streams of feedstocks, intermediate process gases, intermediate process liquids, byproducts, and final products remain in their own separate piping.

PTOA Readers and Students heat things up indirectly all the time when cooking; nobody would pour a can of soup directly on the burner of a gas or electric range to heat the soup up!

Heck no! The soup is poured into a container like a sauce pan and the heat from the burner is transferred first through the metal pan and then into the liquid soup.

 

Industrial Heating and Cooling
Is Accomplished By Heat Transfer 

In the processing industries and at your home, things are heated up and cooled down using the transfer of heat through materials...which is logically called heat transfer.

The temperature-changing equipment simply would not work without heat transfer taking place. Therefore, the design of industrial-sized temperature-changing equipment purposefully enhances heat transfer.

Doesn't it sound kinda nuts that "heat can be transferred" even while the process stream is cooling down?

That weirdo statement is just one of those jargon things PTOA Readers and Students will soon understand.

A future PTOA Focus Study Area on heat transfer will explain everything so don't stress about that now. The plan is to first introduce the temperature-changing equipment and later apply the basics of heat transfer to learn how to optimally operate the equipment.

 

PROCESS TEMPERATURES CAN BE CHANGED DIRECTLY,TOO

PTOA Readers and Students will soon learn that process temperatures can be directly impacted by either releasing heat into or soaking heat out of the flowing process stream.

The temperature of the process stream can be changed directly...while flowing through the process steps...by chemical reactions:

• Some chemical reactions release thermal energy (aka heat)  into the process stream. PTOA Readers and Student will learn that these are called "exothermic reactions."
• Some chemical reactions soak up all the heat they can from the process stream to keep the reaction going.  These are called "endothermic reactions."

Likewise, a process stream temperature is impacted by physical changes...aka phase changes...between solids and liquids and gases:

• PTOA Readers and Students will soon learn that...while the temperature is dropping and a gas in condensing into a liquid...or a liquid is freezing into a solid... thermal energy (aka heat) is released into the surroundings by the process stream that is changing into a more-bound-together form.  For example, while water is freezing into an ice-cube, some heat is released at the surface of the water while it is forming into a cold cube.  No kidding!

• PTOA Readers and Students will soon learn that...while the temperature is rising...and a solid is melting into a liquid...or a liquid is vaporizing into a gas...thermal energy is soaked up by the process stream that is changing state into a less-bound-together form.

Confused? You won't be soon! Keep reading!

Take Home Messages: The next focus study area introduces PTOA Readers and Students to common industrial sized temperature-changing equipment. 

Temperature-changing equipment changes process temperatures indirectly by heat transfer. Heat transfer is the topic of future PTOA segments.

A Fired Heater is an example of temperature-increasing equipment.

A Cooling Tower is an example of temperature-decreasing equipment designed to indirectly cool down process temperatures. 

A Shell-and-Tube Heat Exchanger indirectly swaps thermal energy  (aka heat) between process streams; a hot stream becomes colder and a cold stream becomes hotter. 

Process streams can be directly heated or cooled by the presence of chemical reactions or changes of state/phase changes.

______________________________________________________

The PTOA is a highly integrated study of process technology and process operations.

"Highly integrated" means the PTOA does not waste time with individual classes studying one particular facet of process technology...and eventually get around to connecting-the-dots after years of tuition dollars have been collected.

The integrated format of the PTOA segments will make the most sense to Readers and Students that read the PTOA segments in sequential order.

In other words:

PTOA Readers and Students who may be confused at this point should return to the PTOA Home Page and access the "Start Here for Success" photo block.

"Start Here for Success" will lead the PTOA Reader through the important PTOA Orientation and then to the PTOA segments.

Are you a PTOA Reader who has completed reading the PTOA Orientation and PTOA segments in series...and you are still a little confused? No problem! Just re-read the PTOA segments until your brain is more familiar with  the new concepts and terms. You can do it! Use the convenient bookmarking tool to save your place!

PTOA Readers that wish to discuss PTOA segments with fellow PTOA teammates simply need to re-register as a  PTOA Student. Only PTOA Students have access to PTOA Student forums.  PTOA Student registration is free and 100% confidential.

Access the For Students Only photo block on the PTOA Home Page to register as a PTOA Student.

 

©2015 PTOA Segment 00021
Process Industry Temperature Changing Equipment

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