AGENDA FOR THE “NEW” TECHNOLOGY:
PTFE-LINED THRUST BEARINGS
INTRUDUCTION
NORTH AMERICAN PTFE BEARING
ENERGY KEEPERS
ENENERGO
ONTARIO POWER GENERATION
PTFE a.k.a. TEFLONR
BACKGROUND
RESEARCH & DEVELOPMENT
EXPERIENCE
KERR HPP UNIT 3 PTFE REPLACEMENT
QUESTIONS AND ANSWERS
ENENERGO WAS FOUNDED IN 2004 BY THE DESIGN
ENGINEERS THAT PRIOR TO ITS ESTABLISHING WORKED
FOR UETM , A BIG GENERATOR MANUFACTURER
COMPARABLE TO OUR GE.
THEIR ENGINEERS WERE PART OF THE R & D TEAM IN THE
MID 1960’S THAT DEVELOPED THE PTFE BEARING.
WITH THEIR EXTENSIVE KNOWLEDGE GAINED WAS A
GOOD BASIS FOR THE FOUNDING OF THE ENENERGO
COMPANY
North American
PTFE Bearing, LLC
FOUNDER/OWNER
Kjell V. Nyqvist
105 W Horizon Circle
BOISE, IDAHO 83702
OFFICE: 1-208-345-0833
MOBILE: 1-208-631-9756
E-MAIL: [email protected]
Web: ptfehydro.com
ALFRED MOHINOSENIOR MECHANICAL ENGINEER
INTRODUCED THE FIRST PTFE THRUST BEARING IN NORTH
AMERICA IN 1999
ONTARIO POWER GENERATION OWNS 69 HYDROELECTRIC
GENERATING STATIONS WITH AN INSTALLED CAPACITY OF
13,000 MW
69 OF WHICH 14 ARE OPERATING WITH PTFE THRUST
BEARINGS FOR A TOTAL OF 40 PTFE THRUST BEARINGS
5 units, 5 years, 150 rpm, 286 ton, 2.5 MPa (360 psi), 8 pads
1,415 cm2 (219.3 in2), no noticeable liner wear
Manitou Falls 5 x 15 MVA G.S., Ontario, CANADA
Energy Keepers, Inc.
Gary Peterson, PE
Maintenance Manager
Selis Ksanka Qlispe Project Works
(Kerr Project #0005)
A Corporation of the Confederated Salish
and Kootenai Tribes
43069 Kerr Dam Road
Polson, MT 59860
PolyTetraFlouroEthylene, PTFEBetter known as TEFLONR
On April 6, 1938, Dr. Roy J. Plunkett, DuPont, discovered a white, waxy solid when checking
a frozen, compressed sample of tetraflouroethylene, a gas related to FreonR.
TFE spontaneously polymerized into PTFE. TeflonR was registered as DuPont’s trademark
for PTFE in 1945.
Prominent properties:
Specific gravity 2.15
Tensile strength 21-35 MPa 3,000-5,000 psi
Elongation 300-500%
Flexural Modulus 500 MPa 72,000 psi
Folding Endurance >106 cycles
Impact Strength 189 J/m 3.5 ftlb/in
Hardness 50-65 Shore D
Friction Coefficient 0.1 <3 m/min <10 fpm
Melting Point 327oC 621
oF
Max. Op. Temp. (20,000 h) 260oC 500
oF
Dielectric Constant 2.1
Resistivity >1018 ohm-cm
CONVENTIONAL WHITE METAL (BABBITT)
LINED THRUST BEARINGS
Main Cause of Mechanical Failures of Hydro Generators’ Thrust Bearings
o Thermal Deformation, Crowning
o Low Flexibility; Alignment Critical
o High Susceptibility to Particles
o Wipes One, Wipes All
TECHNICAL SPECIFICATION &
INSTRUCTIONS FOR INSTALLATION &
OPERATION
CONTENT:
1. Purpose
2. Technical Data
3. Product Description
4. Preparation Before Installation
5. Installation
6. Operation and Maintenance
7. Instructions for Transportation and
Storage
SOLUTION
Joint Russian Team Figured out How to
Bond the PTFE to the Metal Base by
Impregnating a Wire Mesh with the PTFE
which was then soldered to the Metal Base
REWARD
Highest Award in Science and
Technology, Russia, 1985
Vladimir P. Loshkarev, Chief Design
Engineer, UETM (Now EnEnergo), was
Awarded the USSR State Prize for
development of hydro units thrust
bearings with PTFE coated segments
38 Years Operation
More than 800 Delivered
CHALLENGE 2
First Commercial Application, 1978
Ust-Ilim, 18 x 282.5MVA, 125rpm, 1,650ton
(3,637,623 lbs) , 16pads, 6.3MPa (913.802 psi)
The below cross section of a PTFE-lined thrust shoe shows
pre-drilled and NPT threaded hole for insertion of a
temperature sensor
Also notice the slot through the friction surface metal flex
PTFE composite above the sensors tip transferring the oil
film temperature
Below Plan and Section Drawings shows
the Wear Marks that are typically provided
with 2 or 4 shoes of the set’s PTFE friction
surfaces
Depth of wear marks are
0.05, 0.1, 0.15, and 0.2 mm
Complex and complicated design for this Babbitt bearing is to
minimize the risk of deformation and wipe can be made simpler
with the insulated properties of the PTFE- lined thrust bearing.
This shows the replacement PTFE-lined thrust bearing shoe that
replaced the previous shown complex design. All PTFE shoes are
made to the exact fitting dimensions as the old Babbitt thrust
bearing shoe’s for easy replacement installation.
LONGEVITY OF PTFE-LINED THRUST BEARING
To establish a wear rate of PTFE-lined thrust bearings
one would have to go back to its infancy when the first
such bearings were put into commercial operation in
1978 at the Ust-Ilim hydropower plant. These liners
have 1.5 mm of wearable thickness. Protracting from
actual wear rates, the longevity is expected to be
between 40 to 70 years.
Of course, the wear rate depends on different
operating conditions. Below are listed a few
hydropower plants with different operating
conditions and parameters to indicate measured
wear rates so far.
After twenty (20) years of operation at the 18 x 283
MVA Ust-Ilim HPP on the Angara River in Russia
the wear of the 16 segment thrust bearing with a
total load of 103 metric ton was 0.3 mm (0.012 in.).
9 units, 15 years, 200 rpm, 1,720 ton, 6.0 MPa (867.6 psi), 12 pads
2,350 cm2 (364.3 in2), 0.32 mm (0.013 in) liner wear
The thrust bearings at the Zagorsk Pumped Storage
Plant north of Moscow with six units each rated
236 MVA, 150 rpm, axial thrust 1,460 ton, without
HPOL, and 1,200 starts annually were inspected
after fourteen years uninterrupted
operation and found in excellent condition with
0.2 mm wear (0.008 in).
TEHRI HYDROELECTRIC
PROJECT INDIA
First delivery in 2001
In commercial operation since
2003
4 x 278MVA, 214.3rpm,
Total thrust load: 1,500ton
(3,306,930lbs)
Number of pads: 12
Pad area: 2,190cm2 (339.5sqi)
Specific load: 5.8MPa (812.1psi)
Mean velocity: 24.9m/s (81.7fps)
North American
PTFE Bearing, LLC
FOUNDER/OWNER AND
GENERAL MANAGER
Kjell V. Nyqvist
105 W Horizon Circle
BOISE, IDAHO 83702
OFFICE: 1-208-345-0833
MOBILE: 1-208-631-9756
E-MAIL: [email protected]
Web: PTFEHYDRO.COM