Compressors

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Compressors Drivers
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Compressor

• Types
• Dynamic
• Centrifugal
• Ejector
• Displacement
• Positive Diplacement
• Issues
• Control
• Seals

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MOTIVE FLUID
DISCHARGE
SUCTION
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Axial
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SUCTION
DISCHARGE
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ESTIMATOR CHOICES
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Selection Chart
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ESTIMATOR - Compressor Input
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Fluid Power Calculation

• Fluid Static Head -gt approx. 0
• Include Piping Frictional Losses of 10 psi per
  segment between equipment.
• Exchanger Losses per simulation assumptions
• Control Valve losses (15 psi for our 500 psig
  system - but eliminate if possible?).
• Fluid Flow
• Efficiency (75 to 80)

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PRO II Output
Seals Normally Limited to 350 F (180 C)
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Compression Ratio

• P2 / P1 (absolute pressures)
• Not required in our calcs for cost but if
  excessive are an indication that a multistage
  compressor would be required (usually confirmed
  by outlet temperature).

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Centrifugal Compressors and Fans Performance
Controls
Diff Press
Okay
Surge
Inlet Volumetric Flow Rate
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Centrifugal - Control

• For constant discharge pressure systems (most
  common). Variations in process flow rate are
  controlled through the inlet valve

Inlet Vane Changes The Flow vs DP Curve of the
Compressor
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Centrifugal - Control
Surge Line
Diff Press
Open Inlet Valve
Closing Inlet Valve
Inlet Volumetric Flow Rate
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Centrifugal - Control

• At the point where further restriction in the
  inlet valve would cause surging other controls
  are required.
• Usually
• Blow Off
• Recirculation

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Centrifugal - Control

• Blow Off

Blow Off
Blow Off Valve
Inlet
Disch
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Centrifugal - Control

• Recirculation

Inlet
Disch
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Centrifugal - Control

• Variable Speed
• Used on the smaller compressors for energy
  efficiency

Diff Press
High RPM
Low RPM
Inlet Volumetric Flow Rate
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Drives For Pumps and Compressors
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Drives For Pumps and Compressors
T.E.F.C.
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TEFC
Air Flow
seal
bearing
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Electric Drives

• Enclosures
• protected from outside environment
• allows free ambient room air to cool windings
• drip proof guarded
• weather protected
• Totally Enclosed Fan Cooled
• TEFC most common motor used - isolated from the
  free exchange of outside air
• Explosion Proof - designed to isolate
  surroundings from ignition sources such as
  sparking or high temperatures inside the motor

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Electrical Area Classification

• Performed by electrical and process engineers
• Process of classification
• identifies processes that have explosion
  potential
• flammable liquids, gases, vapors, combustible
  dust, or ignitable fibers or flyings
• based on flash point, operating temperature etc.
• Identifies distances from process that are safe
• identifies equipment and instrumentation
  enclosure requirements
• i.e. Explosion proof

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Our Compressor

• What composition we have going through
  compressor?
• Is the material a fire/explosion hazard (operated
  above its flash point) ?
• Do we have an explosion potential if it leaks out
  of compressor?
• What drive type should we choose?