Centrifugal Compressors and Pumps (Sealing System of Compressors Shall Be Dry Gas Seals)

Introduction

The course will introduce delegates to the different types of pumps, motors and drives and their associated terminology. Centrifugal and positive-displacement pumps and compressors, packing, mechanical seals and sealing systems, bearings and couplings will all be discussed. The application of the different types of pumps and compressors will be discussed along with their suitability for different operational duties. Pump operation, troubleshooting and maintenance will be dealt with in depth.

The highlights of this course are:

• Compressors and compression systems
• Pumps and pumping systems
• Discussion of mechanical and dry gas seal design and associated issues
• Predictive Maintenance techniques
• Motors and Variable Speed Drives

Objectives

At the end of this course, participants will have:

• Have an understanding of the different types of pumps and compressors
• Be able to operate pumps and compressors as close as possible to the design efficiency
• Will be able to monitor pump and compressor efficiency, availability and reliability
• Have learnt about selection, operation and maintenance strategies
• Be able to troubleshoot pump and compressor problems
• Be able to specify, operate and maintain fluid movers and drivers

Training Methodology

The course will be conducted along workshop principles with formal lectures, case studies and interactive worked examples. Relevant case studies will be provided to illustrate the application of each tool in an operations environment. Each learning point will be re-enforced with practical exercises. There will be ample opportunities for discussion and sharing experiences.

Who Should Attend?

This course is directed towards:

• Supervisors, Team Leaders and Professionals in Maintenance, Engineering and Production
• It is suitable for Professionals who expect to become involved at any stage in project applications and applicable maintenance technologies

The course will also benefit those who wish to update themselves on pump and compressor technology, judge the suitability of different types of pumps and compressors for their needs, and learn how to operate and maintain them for the benefit of their organisations.

Course Outline

DAY 1: Compressors

• Compressor types: positive displacement (reciprocating and rotary), and dynamic (centrifugal and rotary), compressor operation, gas laws

• Compressor performance measurement, inlet conditions, compressor performance, energy available for recovery

• Positive displacement compressors, reciprocating compressors, reciprocating compressors, diaphragm compressors

• Rotary compressors, rotary screw compressor, lobe type air compressor, sliding vane compressors, liquid ring compressors

• Dynamic compressors, centrifugal compressors, axial compressors

• Air receivers, compressor control, compressor unloading system

• Intercoolers and aftercoolers, filters and air intake screens

Centrifugal & Axial Compressors

• Principle of operation of centrifugal and axial flow compressors, characteristics of centrifugal and axial flow compressor

• Surging, choking, bleed valves, variable stator vanes, inlet guide vanes

DAY 2: Pumps

• Pump definition, pump categories: dynamic and displacement reciprocating & rotary

• Centrifugal pumps: theory of operation of a centrifugal pump, casings and diffusers, radial thrust, hydrostatic pressure tests

• Impeller, axial thrust, axial thrust in multistage pumps, hydraulic balancing devices, balancing drums, balancing disks

• Centrifugal pumps general performance characteristics, cavitations, net positive suction head and requirements

Bearings & Lubrication

• Types of bearings, ball and roller bearings, stresses during rolling contacts

• Statistical nature of bearing life, materials and finish, sizes of bearings, types of rolling bearings, thrust bearings

• Used oil Analysis: proper lube oil sampling technique, test description and significance, visual and sensory inspections, chemical and physical tests, water content, viscosity, emission spectrographic analysis, infrared analysis, total base number (TBN), total acid number (TAN), particle count, summary

DAY 3: Positive Displacement Pumps

• Reciprocating pumps, piston pumps, plunger pumps, rotary pumps, screw pumps, lobe pump

• Cam pumps, vane pumps, metering pumps

Pump Selection

• Engineering of system requirements, fluid type, system head curves, alternate modes of operation, margins, wear, future system changes

• Selection of pump and driver, pump characteristics, code requirements, fluid characteristics, pump materials, driver type

• Pump specification, specification types, data sheet, codes and standards, bidding documents, technical specification, commercial terms, special considerations, performance testing, pump drivers

• Special control requirements, drawing and data requirements form, quality assurance and quality control, bidding and negotiation

• Public and private sector, bid list, evaluation of bids, cost, efficiency, economic life, spare parts, guarantee/warranty, simple bid evaluation

DAY 4: Mechanical Seals

• Basic components, temperature control, seal lubrication/leakage, typical single inside pusher seal

• Maintenance recommended on centrifugal pumps, recommended pump maintenance

Vibration Analysis & Predictive Maintenance

• Vibration instrumentation, velocity transducer, acceleration transducer, transducer selection, time domain, frequency domain, machinery example, vibration analysis

• Vibration causes, forcing frequency causes, unbalance, misalignment, mechanical looseness, bearing defects, gear defects, oil whirl, blade or vane problems, electric motor defects, uneven loading, drive-shaft torsion

DAY 5: Maintenance of Motors

• Introduction to AC induction motors and their construction, rotor slip and principles of operation, equivalent circuit, torque-speed characteristics, motoring and regenerative region of operation

• Starting of induction motors and associated techniques

• Speed control methods of induction motors

• Characteristics of motors, enclosures and cooling methods, application data, design characteristics, insulation of AC motors

• Failures in three-phase stator windings, predictive maintenance, motor troubleshooting, diagnostic testing for motors

Variable Speed Drives

• Basic principles of AC Variable-Speed Drives (VSD's), constant torque reg ion, constant power (extended speed) region, four quadrant operation

• Power semiconductors, diode, thyristor (SCR), IGBT, MOSFET, GTO and others

• Inverters, Voltage-source and Current-source, Pulse Width Modulated (PWM) inverters