PumpsPumps

Unit 10Unit 10

Learning Objectives

• TLW be able to describe the following about pumps used in the process industry:– Types– Uses– Operation– Monitoring– Maintenance– Troubleshooting– Hazards

Warm up QuestionsWarm up Questions

• How are dynamic pumps different from positive displacement pumps?

• What are some hazards associated w/ the operations of pumps?

• What is cavitation? What can cause it?

• List 3 monitoring and maintenance activities associated w/ pumps.

Today’s AgendaToday’s Agenda

• Purpose/function of pumps• Applications in the Process

Industry • Types of pumps and their

applications • Pump hazards• Monitoring and maintenance• Symbols

Pumps in the Process Pumps in the Process IndustryIndustry

• Purpose: to cause liquids to flow through a process

• Liquids are cohesive (molecules touch each other) but have no definite shape

• Slurries – liquid/solid mixture

Types of PumpsTypes of Pumps

Positive Displacement Dynamic

Reciprocating Rotary Centrifugal Axial

Piston & Cylinder GearsDiaphragm Screws

LobesCamsVanes

Centrifugal PumpsCentrifugal Pumps

• Operating principle – centrifugal force caused by circular rotation

• Used to move large volumes of liquids w/ low viscosities

• Centrifugal force spins liquid away from the center

• Can be mounted in horizontal or vertical position

Positive Positive Displacement Pumps Displacement Pumps

Reciprocating•Piston or other mechanism moves back and forth•Intake stroke – admits fluid into chamber•Discharge Stroke – discharges fluid through outlet•Good for metering specific amounts of fluids

Rotary•Screw, gears, lobes or vanes rotate•Moves heavier fluid, viscous fluids, including slurries•Discharges large amounts of fluid at low pressures

Pump HazardsPump Hazards

Improper Operation– Starting pump with discharge closed– Starting pump with drain open– Starting pump with vent open– Poor lubrication

Impacts– Physical - Production– Equipment -

Environment

Monitoring and Monitoring and MaintenanceMaintenance

• Daily• Check pressure across pump• Check oil levels/seals• Drains

• Weekly• Check oil• Wash down• Swap pumps

• Monthly• Change oil• Wash down around pump• Adjust packing

PreventiveBearing, seals, worn parts

• Look– Oil levels– Seal & Flange Leaks– Suction Discharge Pressure

Gauges– Water collecting (bearing failure)

• Listen– Abnormal noises (ex. cavitation)

• Touch– heat– Vibration

• Smell– Leaks– heat

Pump SymbolsPump Symbols

• See handout in section 11

Screw pump – horizontal mount

Vertically Mounted Pump

Piston pump

Diaphragm pump

Gear Pump

Single Screw Pump

Twin Screw Pump

http://www.scs.uiuc.edu/chem_eng/kraftunitops2/image/lobe_pump_animation.gif

Lobed pump

Internal gear pump

Sliding Vane pump

Multistage Pump

Multistage pump impeller

Multistage pump w/ driver (motor)

Independent Practice

• Pump Components Worksheet• Pump Curve Exercise