18-03-2011, 04:09 PM
Presented By:
Ngangkham Peter Singh
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Composite materials and technology in the manufacturing of windmills
Windmill history
200 B.C.-1st wind machines used in Persia for grinding grains
7th century- 1st practical windmill used in Sistan pumping and grinding
14th Century- Dutch windmills were in use to drain areas of the Rhine River delta
1887- 1st electricity generation in Scotland by James Blyth
1888- 1st automatically operated wind turbine was built in Cleveland by Charles F. Brush
Types of windmill in the modern world
Horizontal Axis Wind Turbine
Vertical Axis Wind Turbine
Horizontal axis
The wind direction and the rotor are in the same direction.
Mostly used design
Materials used
In earlier times
Steels
Wood
Poly foam and Aluminum
Present times
Fiber glass and Epoxy Resin, Vinyl Ester
Carbon Fibers and Epoxy Resin, Vinyl Ester
Manufacturing of HAWT blades
Processes used
Hand lay up process
VARIM process
Materials required
EPS foam
Model table
Resin
Glass fabrics
Heaters
Accessories
Vacuum pump
Manufacturing steps
Model table and model
Preparation of mould
Manufacturing of windmill blades
Model table and model
Model table preparation
Foam cutting
Joining of the separate blocks
Lamination
Finishing
Contour checking
Preparation of the mould
Hand lay up process
Multiple passing
Curing
Thermoset and heaters embedded
Metal frame also attached
Lay up of the mould
Finishing operations
Manufacturing of blades
Steps
Layup of moulds
Vacuum testing
VARIM process
VARIM Process
Vacuum assisted resin infusion method
Vacuum pulls the resin through the lay out
P1=Atmospheric Pr
P2=Applied Vacuum Pr
Preparation
Injection
Vacuum reduction
Curing
Additional materials are removed after curing
Fill time
Darcy’s Law:
Flow of fluid in a porous material
Software pack to determine the feeding point
Stages of Resin impregnation
Assembly
Cured parts are joined
Parts include
Nose insert
Root insert
Shear plate
Two halves of the blade
Finishing
Dry finishing
Sanding
Painting
PU paints
Nacelle Cover and Nose Cone
Made by hand lay up process
Finishing operations
Assembly
Problems
Dry glass
Air in laminates
Foam burning
Wrinkle
Variations in paint thickness
Corrosion
Improper bonding
Conclusion
VARIM process is used for the production of windmill blades.
Advantages of VARIM are
Unskilled labour
Constant thickness
Minimum thickness and shrinkage
Faster cycle time
No pollution from volatile organic compounds
Better fiber to resin ratio
Nacelle covers and Nose cone are produced by hand lay up process
Composite materials used are combination of Vinyl Ester or Epoxy resin and Glass fabrics or Carbon Fabrics in the manufacturing of windmills