1. Fans & Heaters technical seminar
Maintenance & service planning: Centrifugal Fans
Chris Brown – Aftermarket Project & Service Manager

2. Maintenance & Service Planning
Introduction
Key Benefits
Typical Maintenance
Types of Maintenance
Preventative Maintenance
Corrective Maintenance
Fault Finding
Advance Planning
Outage Planning
Howden Specialist Services

3. Maintenance & Service Planning
Introduction

4. Maintenance & Service Planning
Introduction
Centrifugal Fan Standard Key Components

5. Maintenance & Service Planning
Introduction
Various fan design options – depending on process:
Lubrication System
Instrumentation – temperature / vibration monitoring
Box vane control or radial vane control
Wear liners
Type of shaft seal
Type of driver – motor or turbine
Sleeve or roller bearings
Actuator type

6. Maintenance & Service Planning
Key benefits

7. Maintenance & Service Planning
Benefits of Planning Ahead
Reduced downtime caused by unpredicted fault conditions
Financially predictable – uncertainty about costs can affect decision making
Improved reliability of equipment
Early detection of potential problems
Improved economy or performance of equipment
Correct spare parts inventory
Reliable cost predictions that enable you to plan with confidence

8. Maintenance & Service Planning
Typical maintenance tasks

9. Maintenance & Service Planning
Typical Maintenance Tasks
Bearing sleeve change
Replacement of shaft seals
Lube oil filter change
Bearing inspection
Impeller inspection
Clearance checks – inlet cone, shaft seals
Wear liner condition check – depending on application
Impeller replacement

10. Maintenance & Service Planning
Types of Maintenance

11. Maintenance & Service Planning
Types of Maintenance
Three main types of maintenance
Preventative
Corrective
Predictive (future development)
Each of these has benefits and risks.
Howden can assist with your chosen strategy

12. Maintenance & Service Planning
Preventative Maintenance

13. Maintenance & Service Planning
Preventative Maintenance
Preventative Maintenance – Per Shift or Daily
Carry out a visual & audible check on fan & ancillary equipment
Check oil levels and check pipes & bearings for leaks
Check fan & motor bearing temperatures & vibration levels
Check motor power & current and motor winding temperatures
To prevent seizure, move vanes through 50% of travel
Check coolant flow
As per typical Howden instruction manuals

14. Maintenance & Service Planning
Preventative Maintenance
Preventative Maintenance – At Outage
Check impeller for wear or cracking, check cone clearances
Check coupling, seal housings, bearing & pedestal bolts for tightness
Check casing seals for wear or damage
Check coupling alignment

15. Maintenance & Service Planning
Preventative Maintenance
Preventative Maintenance – Annually
Renew lubricating oil
Examine fan bearings and shafts for wear
Check impeller & casing for erosion or cracking
Checks for cracking includes Magnetic Particle Inspection (MPI) or Dye Penetrant Inspection (DPI)
Check cone clearances and fouling
Check coupling for wear and check alignment
Check shaft seals for damage or wear
Check inlet vanes for wear, damage or seizure
Check actuators, linkages for wear damage or seizure
Check tightness of bolts on bearing, seal housing, pedestal, motor & casing
Check impeller balance

16. Maintenance & Service Planning
Check cone clearances
For hot fans, cone is set low.
Cone is bolted to casing and casing is foot mounted on concrete.
When casing rises due to hot gas, cone will centralise in impeller inlet

17. Maintenance & Service Planning
Corrective Maintenance

18. Maintenance & Service Planning
Corrective Maintenance
Corrective Maintenance – Coupling Alignment
Target 0.36mm
Target 0.51mm

19. Maintenance & Service Planning
Fault finding & rectification

20. Fault finding & rectification - Example
High bearing temperature
Cause Suggested remedy
Coolant flow interrupted Investigate cause & restore
Bearing worn Check fan alignment
Check for oil contamination
Seal rubbing Check bearing seals

21. Maintenance & Service Planning
Advance Planning

22. Maintenance & Service Planning
Advance Planning
Advance Planning
Planning is critical to successfully achieving your outage goals in the desired timescales
Unlike servicing your car where parts are available off the shelf in a matter of hours - Fan service items and replacement parts can have varying lead times depending on the item
Identifying these items long lead time items early is critical to successful outage planning

23. Maintenance & Service Planning
Advance Planning
Impeller & shaft – up to 40 weeks

24. Maintenance & Service Planning
Advance Planning
Fan bearing sleeves / housings – 12 to 16 weeks

25. Maintenance & Service Planning
Advance Planning
Fan coupling – 14 weeks Oil pumps – 10 weeks Shaft seals – 8 weeks
Steel membrane coupling
Rubber block coupling
Grid spring coupling

26. Maintenance & Service Planning
Outage Planning

27. Maintenance & Service Planning
Outage Planning
Howden can assist with outage planning no matter how large the scope of work is.

28. Maintenance & Service Planning
Outage Planning – Pre-outage
Add picture
Assessment of work scope & resource planning
Review of work area / site assessment
Interface assessment – ducts / electrical
Installation planning – Milestones and key dates
Project program assistance
Contingency assessments
Crane, lifting & scaffolding assessment.

29. Maintenance & Service Planning
Outage Planning – during outage
How to work safely and productively.
Help with Risk assessments and method statements.
Understanding scope of neighbouring contractors.
Foundation condition checks.
Progress reporting.
Technical guidance on work scope
Quality Control.
Continuous presence during work scope

30. Maintenance & Service Planning
Outage Planning – post outage
Final documentation completion
Acceptance checks
Quality data book
Hot commissioning
Equipment handover

31. Maintenance & Service Planning
Outage Planning – Turnkey
Design of all required parts
Manufacture and Supply of all required parts
Site supervision
Local project management from UK team on site.
Provision of local skilled site labour
UK based project management
Howden can assist with these activities, and more….

32. Maintenance & Service Planning
Howden Specialist Services

33. Maintenance & Service Planning
Howden Specialist Services
Howden Technical Specialist – Additional Services
Balancing & alignment services
Preventative maintenance planning
Guaranteed access to product specialists.
Scheduled TA visits - Health checks on installed equipment/spare parts
Technical Assistance during outages – scheduled and unscheduled
Spare parts assessment & recommendations
Maintenance management #
Performance testing

34. Maintenance & Service Planning
Howden Specialist Services
Specialist Services - Impeller Balancing
The quality of balance to be attained shall be within Grade 2.5 as specified in ISO , E Figure 4 (new impellers).
Following installation or outage, Howden can carry out:
Trim balancing
Hot balancing

35. Maintenance & Service Planning
Howden Specialist Services
Performance Testing
Fan can be tested to check current performance.
This can be used for:
To check guarantee points for newly installed
equipment.
OR:
To assist with selection of replacement or
upgraded equipment.

36. Maintenance & Service Planning
Howden Specialist Services
Performance Testing
Howden can assess site layout and advise on correct location for test ports:
TEST STANDARDS HOWDEN WILL USE:
BS EN ISO 5801:2008 (BS848-1:2007)
BS EN ISO 5802:2008 (BS 848-3:2001)
ISO 13348: 2007 (BS 848-9: 2007)

37. Maintenance & Service Planning
Howden Specialist Services
Howden Health Check
Advance warning is the key to operational security
What you get:
A comprehensive condition report carried out by experienced Howden engineers
The opportunity to schedule and budget for any recommended non-emergency improvements
A full report detailing recommendations

38. Maintenance & Service Planning
Howden Specialist Services – example scenario
Problem statement
FD Fan on power plant exhibiting high levels of vibration.
Action 1:
Impeller was re-balanced (3 Days of lost production from the Unit) & vibration level reduced.
After a period, vibration level increased again and equipment was stopped.
Action 2:
Rubber elements in coupling were wearing. Elements replaced with stiffer elements (5 Days of lost production from the Unit) and vibration level reduced.
TOTAL: 8 DAYS OF PLANT DOWNTIME

39. Maintenance & Service Planning
Howden Specialist Services – example scenario
FINAL ACTION - CLIENT CONTACTED HOWDEN:
A Howden Expert was sent to site who took vibration readings on motor, fan bearings and on fan casing.
Results indicated radial misalignment between motor and fan shaft.
Re-alignment was completed & rubber elements replaced to original specification.
The fan returned to service and the vibration level had reduced and stabilised.
TOTAL: 2 DAYS TO SOLVE PROBLEM
10 days v 2 days = 8 day time saving using Howden Specialists

40. Maintenance & Service Planning
Howden Specialist Services
Quick and reliable advice is key to reduced downtime.
What you get:
Access to experience product specialist providing technical guidance
Fast and effective trouble shooting
Reduced downtime as advice gives a timely resolution to problems or queries

41. What Can Howden Do For You Next?
What Next?
Challenge Howden
What Can Howden Do For You Next?
Outage Planning?
Product Training?
Spare Parts Audit?
Maintenance Planning and Advice?
Product Performance Analysis?
Challenge Howden