THE RELATIONSHIP BETWEEN PROCESS OPERATORS & ROTATING EQUIPMENT

You and me chasing paper
Getting nowhere
On our way back home
We're on our way home
We're on our way home
We're going home

("Two of Us," by The Beatles, 1971)

INTRODUCTION TO ROTATING EQUIPMENT

We have arrived!

The time has come for PTOA Readers and Students to learn about Rotating Equipment ... the complex and expensive process industry equipment that increases the PV Pressure within fluids and thus keeps those fluids flowing through pipes.

The important relationship between the Process Operator and Rotating Equipment goes like this:

The Process Operator who competently understands how Rotating Equipment fundamentally works will properly start up, daily monitor, and properly shutdown the Rotating Equipment and its Auxiliary Systems.

Plant Managers have demanded that Process Technology instruction include a thorough exploration of Rotating Equipment because ...

No PV Pressure → No ΔP.

No ΔP → No Fluid Flow.

No Fluid Flow → Plant Shutdown!

PTOA Readers and Students who embrace learning the myriad of details related to Rotating Equipment will gain knowledge that is both desired by Plant Managers and useful at the processing plant.

So hang in there ... because it's going to get wonky!

ONWARD!

What is meant by "Rotating Equipment?"

The PV Pressure in fluids is increased by movement that can be described as spinning around in circles ...

OR ...

"repetitious displacement" ... which means the process fluid is pushed out of its container by more of the same process fluid.

Because of the required repetitious movement, the equipment that increases the PV Pressure is called "Rotating Equipment."

Rotating Equipment is "Coupled With" A Driver

The (Light Blue) Electric Motor Driver is on the left. The (Darker Blue) Centrifugal Pump is on the right. The horizontal pipe is the Pump Suction Line. The vertical pipe is the Pump Discharge Line.

A Driver is needed to provide the motive force that makes the spinning and displacing motion possible.

Examples of Drivers are Electric Motors and Steam Turbines.

The Driver and Rotating Equipment are carefully matched and "coupled together."

The device called a Shaft Coupling transmits power from the Driver (aka "primary mover") to the Rotating Equipment (aka "driven machine").

Axial and Thrust Bearings

Without any restraint, the constant spinning and displacing motions would create axial thrust and outward radial forces. Eventually, the excessive vibration would cause equipment failure.

Axial Bearings and Thrust Bearings are important components that adorn the Rotating Equipment shaft and offset undesired axial and thrusting motion.

Lubrication Reduces Friction

Metal-to-Metal contact must be lubricated otherwise the heat of friction that is generated will start fusing the metal together.

Lube Oil is required to lubricate the hardware components and any metal-to-metal contact area.

Circulating lubrication oil reduces friction as well as removes heat and dirt from the working surfaces of the Rotating Equipment.

Lube oil is selected to accommodate its intended service; a variety of chemical additives like Viscosity Index Improvers, Anti-Foam Agents, Anti-Rust/Corrosion Inhibitors, etc. may be added to it.

So a Lubricating Oil System is a complete subsystem ... aka Auxiliary System ... that is required to support Rotating Equipment.

Lube Oil Systems have their own Circulating Pumps, Coolers, Filters, Supply Line and a Return Line that flows to the Oil Reservoir. Pressure Instrumentation Alarms when the Oil Pressure is Low and starts a backup pump.

Preventing Process Fluid Leakage

Fortunately the process fluid being pumped is water ... because it is badly leaking!

Assuming the Rotating Equipment is not a vacuum-creating pump ...

The process fluid that is being pressurized will be at a higher PV Pressure than the atmospheric pressure that surrounds the Rotating Equipment-Driver assembly.

The ΔP that results will thus favor leaking the process fluid from the internals of the Rotating Equipment to the lower pressure of the surrounding environment.

Therefore ...

Seal Oil is use to prevent the process fluid from leaking into the atmosphere.

Alternatively, a mechanic means like mechanical seals, O-rings, and glands may perform the sealing function.

In some applications, the lube oil can meet the specifications of the seal oil.

When that is not the case, a separate Seal Oil Auxiliary System must likewise be installed to support the Rotating Equipment.

Gee!

It sure takes a lot of supporting components and auxiliary systems to create what would otherwise be the simple spinning and repetitive displacement motion that increases the PV Pressure in fluids!

That's why Mechanic Techs and Process Operators must freely communicate and work together to extend the working life of Rotating Equipment.

COMMON PROCESS INDUSTRY "ROTATING EQUIPMENT"

Examples of Rotating Equipment and their uses are:

Pumps are installed to add the PV Pressure to liquids and condensed vapors so that they can flow and be circulated.
Compressors are installed to add the PV Pressure to gases and vaporized liquids so that they can flow and be circulated.
The fans in Fin Fan Coolers/Condensers and Cooling Towers have already been featured in the PV Temperature Focus Study Areas (PTOA Segment #38 and #39).
Blowers are simply fans that move air from one area to another area.
Site specific Rotating Equipment includes Conveyor Belts and Size Reduction Crushers and these will not be featured in the PTOA.

Turbines are Rotating Equipment AND Drivers!

Steam and Gas Turbines are Rotating Equipment Drivers because the spinning motion they produce provides the motive force that drives a coupled piece of Rotating Equipment.

Since the spinning rotation of Turbines can be increased and decreased, Turbines are typically installed when there is a need for a Variable Speed Driver.

THE PTOA PV PRESSURE ROTATING EQUIPMENT FOCUS STUDY CONTENT

This PTOA PV Pressure Rotating Equipment Focus Study will feature Pumps, Compressors, and Steam Turbines.

The HydroTurbine (Driver) is coupled with and rotates an Electricity Generator. The hydrostatic head of the dammed water is converted into a constant velocity flow of water that rotates the turbine blade.

(Natural) Gas Turbines (GTs), Water Turbines, and Wind Turbines will be featured in the future PTOA Electricity Generation and Distribution Focus Study Area.

The modern Process Operator is expected to possess core competency with respect to identification of Rotating Equipment internal hardware and understanding the purpose of each component.

In addition, modern Process Operators must understand the following terms and how they each impact proper operations of Rotating Equipment:

Pumps: Affinity Laws, Cavitation, PD Safety Pressure Relief, Fluid Viscosity, Internal Fluid Slip, Available and Required Net Positive Suction Head (NPSH), Preparing Pumps for Maintenance, Priming, Pump Characteristic Curve, Pump Efficiency, Pump Failure Causes and Troubleshooting, Total Head, Vapor Pressure of Pumped Fluid.

Compressors: After Coolers, Compressor Efficiency, Compressor Failure Causes, Interstage Cooler, Dryers and Flash Drums, Failure Causes and Troubleshooting, Internal Slip, PD Safety Pressure Relief, Discharge/Suction Pressure Ratio, Snubbers, Surge Awareness and Control.

Steam Turbines: Governor, Heat Soaking, Hunting, Overspeed Trip, Sentinel valve, Steam Quality/Steam Trap, Thermal Shock Avoidance.

The Steam Turbine (Green) expands steam from the Boiler (Reddish) and in the process spins an Electricity Generator (Outlined in Blue).

EVERYTHING ELSE IS CLASSIFIED AS "STATIONARY EQUIPMENT"

Since Rotating Equipment has been defined, this is about as good a place as any to describe the other category of process industry equipment, "Stationary Equipment."

PTOA Readers and Students who are reading the PTOA Segments in the intended sequential order already possess a core competent understanding of the Stationary Equipment that is associated with the PV Temperature, for example:

Package and Waste Heat Boilers.
Cooling Towers.
Fired Heaters and Reaction Furnaces.
Shell and Tube Heat Exchangers.

The future PTOA PV Flowrate Focus Study Area will feature the Stationary Equipment that distributes the fluids that flow throughout the processing complex:

Piping
Pipe Fittings
Valves

The future PTOA PV Level Focus Study Area will feature the Stationary Equipment that contains and separates fluids into separate phases:

Tanks and Tank Farms
Two and Three Phase Separator Vessels

The future PTOA Process Industry Systems Focus Study Area will illustrate how each of the common examples of Stationary Equipment are incorporated into value-added processing systems.

Fluidized Catalyst Regenerators.
Fixed Bed and Continuously Catalyst Circulating Reactors.
Physical Separators by boiling point for example: Atmospheric Crude Towers, Vacuum Towers, Stabilizer Towers.
Physical Separation by Flashing for example: High Pressure and Low Pressure Separators.
Physical Separation by Extraction/Substrate Affinity: Absorbers, Strippers, Adsorbers.
Physical Separation Auxiliary Equipment, for example: Overhead Condensers and Reboilers.

TAKE HOME MESSAGES: Rotating Equipment increases the PV Pressure in fluids.

Process Operators must understand the fundamental operating theory of Rotating Equipment so that they are aware how to properly start up, daily monitor, and shutdown the equipment and associated Auxiliary Equipment.

Modern Plant Managers demand that modern Process Operators competently understand the design and efficient operation of Rotating Equipment.

The movement that increases the PV Pressure in Rotating Equipment is simple spinning or repetitious displacement of the process fluid ...

However, successful operation of Rotating Equipment requires complex technology so that the simple movement will be sustained:

Bearings must offset the shaft's axial and radial movements.
A Lube Oil Auxiliary System must supply fresh and return spent lube oil so that friction-generated heat and dirt are removed.
A separate Seal Oil Auxiliary System may be required to prevent process fluid leakage into the surrounding atmosphere.

All Rotating Equipment is carefully coupled to and aligned with a Driver that provides the motive force which creates the spinning or displacement movement.

Examples of Drivers are Electric Motors and Steam Turbines.

The Shaft Coupling has the important duty of transferring power from the Driver (aka "primary mover") to the Rotating Equipment (aka "driven machine").

Pumps and Compressors are common Rotating Equipment which is installed to increase the PV Pressure in process fluids so that they can flow and circulate throughout a processing facility.

Steam Turbines, Water Turbines, and Wind Turbines are examples of Variable Speed Drivers that are coupled to drive a different piece of Rotating Equipment ...

For example, a Steam Turbine, Gas Turbine, and Wind Turbine can spin an electricity generator.

The other general classification of process industry equipment is "Stationary Equipment." PTOA Readers and Students already possess a core competent understanding of the Stationary Equipment that is associated with the PV Temperature.

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