U.S. patent application number 13/400867 was filed with the patent office on 2013-08-22 for wind turbine tower.
This patent application is currently assigned to FABCON, INC.. The applicant listed for this patent is Gregory J. Havlik, Thomas M. Kuckhahn, George E. Miks. Invention is credited to Gregory J. Havlik, Thomas M. Kuckhahn, George E. Miks.
Application Number | 20130212963 13/400867 |
Document ID | / |
Family ID | 48981192 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130212963 |
Kind Code |
A1 |
Miks; George E. ; et
al. |
August 22, 2013 |
Wind Turbine Tower
Abstract
A wind tower erected on a foundation in which individual levels
are formed by connecting a plurality of cast concrete panels along
their vertical joints. Additional levels are installed on each
prior level and secured with an all-thread post tensioning system
and couplers.
Inventors: |
Miks; George E.; (Shakopee,
MN) ; Kuckhahn; Thomas M.; (Prior Lake, MN) ;
Havlik; Gregory J.; (Chanhassen, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Miks; George E.
Kuckhahn; Thomas M.
Havlik; Gregory J. |
Shakopee
Prior Lake
Chanhassen |
MN
MN
MN |
US
US
US |
|
|
Assignee: |
FABCON, INC.
Savage
MN
|
Family ID: |
48981192 |
Appl. No.: |
13/400867 |
Filed: |
February 21, 2012 |
Current U.S.
Class: |
52/223.4 ;
52/223.13; 52/223.14; 52/296; 52/745.17 |
Current CPC
Class: |
E04C 5/122 20130101;
E02D 27/425 20130101; E04H 12/16 20130101; E02D 27/42 20130101 |
Class at
Publication: |
52/223.4 ;
52/296; 52/745.17; 52/223.14; 52/223.13 |
International
Class: |
E04H 12/16 20060101
E04H012/16; E04C 5/12 20060101 E04C005/12; E04C 5/08 20060101
E04C005/08; E02D 27/42 20060101 E02D027/42; E04H 12/00 20060101
E04H012/00 |
Claims
1. A wind turbine tower comprising: a) a concrete foundation; b) a
first level of a plurality of cast, flat or substantially flat
concrete panels, said concrete panels each having an enlarged
corbel side along a vertical edge to which an adjacent concrete
panel is secured, said corbel sides including a sleeve to accept a
wire strand to link all panels in said first level around an inner
periphery of said first level defined by the plurality of concrete
panels; c) a second level of a plurality of cast, flat or
substantially flat concrete panels, each said concrete panel
including enlarged corbel sides as in said first level and linked
together in said second level as in the first level, said second
level being positioned on top of said first level; d) further
levels of a plurality of cast concrete panels, each arranged on top
of a lower level until the desired height has been achieved; and e)
each level of cast concrete panels including an all-thread post
tensioning system and couplers to connect first to the foundation
via anchor bolts and then to each level such that each level is
securely secured to adjacent levels.
2. A method for fabricating a wind tower comprising the steps of:
(a) building a tower foundation including anchor points for a wind
tower; (b) forming a first tower level from a plurality of cast,
flat or substantially flat concrete panels, said concrete panels
each having an enlarged corbel side along a vertical edge to which
an adjacent concrete panel is secured, said corbel sides including
a sleeve to accept a wire strand to link all panels in said first
level around an inner periphery of said first level defined by the
plurality of concrete panels, linking said concrete panels together
through said sleeves with wire strand; (c) connecting said first
tower level to said foundation anchor points and to an all-thread
post tensioning system within each panel running vertically in each
panel; and (d) forming additional tower levels on top of a lower
tower level using a plurality of said concrete panels with each
said panel connected to an adjacent concrete panel in each tower
level with wire strand through sleeves in corbel sides of each
panel, each succeeding level being connected to a preceding level
and any upper level by the all-thread post tensioning systems in
each concrete panel running vertically.
3. The method of claim 2 further including the step of further
providing connections between adjacent concrete panels in each
level via plates in each panel and bolts.
4. The method of claim 2 further including the step of forming a
wheel adjacent the top of at least one level via a plurality of
spokes connected to each panel in said level and extending inwardly
toward a center of the levels and interconnecting the spokes at or
near said center.
5. The method of claim 2 wherein each tower level above the first
level is constructed on site and lifted on top of the tower.
6. The method of claim 2 wherein each level includes a plurality of
dimples and/or protrusions on the bottom and top of said panels as
locating lugs to mate with another level.
7. A concrete panel for use in constructing wind towers comprising
a generally trapezoidal panel having a wider bottom than a top, a
pair of vertical sides with an enlarged corbel along each side,
said panel defining an inner and outer face, said corbels being
reinforced with reinforcing rod and cables, said concrete panel
further including a plurality of openings extending from the bottom
through said top to accommodate a post tensioning system.
8. The concrete panel of claim 7 wherein said corbels include a
sleeve along the inner face such that a cable may be passed from
one corbel to the other for interconnections to another similar
panel.
9. A wind turbine tower comprising: a) a concrete foundation; b) a
first level of a plurality of cast, flat or substantially flat
concrete panels, said concrete panels each having an enlarged
corbel side along a vertical edge to which an adjacent concrete
panel is secured, said corbel sides being linked to each adjacent
panel mechanically in said first level around an inner periphery of
said first level defined by the plurality of concrete panels; c) a
second level of a plurality of cast, flat or substantially flat
concrete panels, each said concrete panel including enlarged corbel
sides as in said first level and linked together in said second
level as in the first level, said second level being positioned on
top of said first level; d) further levels of a plurality of cast
concrete panels, each arranged on top of a lower level until the
desired height has been achieved; and e) each level of cast
concrete panels including an all-thread post tensioning system and
couplers to connect first to the foundation via anchor bolts and
then to each level such that each level is securely secured to
adjacent levels.
10. The wind turbine tower of claim 9 wherein each level of said
tower includes post tensioning rings securing each of the corbel
sides to one another.
11. The wind turbine tower of claim 9 further including a wheel
formed adjacent the top of each level by connecting each panel of
said level to a spoke which in turn is connected to a central
hub.
12. The wind turbine tower of claim 9 wherein said panels include a
plurality of dimples and/or protrusions on the bottom and top of
said panels as locating lugs to mate with another level.
13. The wind turbine tower of claim 9 further including metal
plates between each mating corbel which are bolted to each corbel
to thereby join each panel to the adjacent panel.
14. The wind tower of claim 9 further including a sleeve through
said corbel sides such that a cable may be passed from one corbel
to an adjacent corbel for interconnecting adjacent panels.
15. The wind tower of claim 14 wherein a post tensioning system is
run through each corbel side sleeve and tensioned to interconnect
all panels within a level.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] Wind towers have progressively grown higher and higher in
order to reach wind that is more consistent. One hundred meter
towers fulfill the height requirement but are so massive that
construction is quite expensive and requires components that cannot
be readily trucked to the site without difficulty. This invention
relates to a wind turbine tower and more particularly to a wind
turbine tower that may be assembled from a plurality of
prestressed, precast concrete cast panels.
[0004] The art described in this section is not intended to
constitute an admission that any patent, publication or other
information referred to herein is "prior art" with respect to this
invention, unless specifically designated as such. In addition,
this section should not be construed to mean that a search has been
made or that no other pertinent information as defined in 37 C.F.R.
.sctn.1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
[0005] The invention provides a wind tower that may be erected on a
foundation using a plurality of panels that are separately cast and
brought on site for erection. Wind towers are often built to 100
meters or more in height. This means that the base of wind towers
can be massive and may exceed the normal carrying limits for
flatbed trucks. While it is possible to have over-size loads, often
such loads must be re-routed past lower bridges, power lines and
similar barriers. The invention builds wind towers of whatever
height is required by forming multiple levels, with each level
being made from a plurality of panels. Each panel has corbel sides
that is enlarged and forms the vertical joint with adjacent panels.
An all-thread post tensioning system is in each panel running
vertically with couplers connecting each panel at their horizontal
joints. Each corbel has ties through the corbels for strengthening
and a sleeve in the corbels accepts a wire strand that may be
routed through each corbel to link all panels together around the
inner periphery. Ferrules inserted into the panel and bolted to the
concrete are also used to make the connections between adjacent
panels in each level.
[0006] Additional levels are added on top of each assembled level
of panels with the all-thread post tensioning system and couplers.
Near the top of each level a "wagon wheel" is formed during
construction with bolts to each panel that attach "spokes"
consisting of beams that extend toward the tower center such that
one beam for each panel is directed toward the center of the
tower.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A detailed description of the invention is hereafter
described with specific reference being made to the drawings in
which:
[0008] FIG. 1 is a front elevational view of the subject of the
invention shown with subterranean foundation portion below
grade;
[0009] FIG. 2 is a bottom plan view with shallow depth of field of
the assembled first level thereof;
[0010] FIG. 3 is a top plan view of the top level of the assembly
of FIG. 1 with shallow depth of field;
[0011] FIG. 4 is an elevational view of one of the plurality of
panels of the first level;
[0012] FIG. 5 is a top plan view thereof;
[0013] FIG. 6 is a bottom plan view thereof;
[0014] FIG. 7 is an enlarged view of the top plan view of FIG. 5
showing greater detail thereof;
[0015] FIG. 8 is an enlarged bottom plan view of the bottom plan
view of FIG. 6 showing greater detail thereof;
[0016] FIG. 9 is a perspective view of the subject of FIG. 6 with a
fragmentary part of the second level and shown from below, outside
and to the left thereof;
[0017] FIG. 10 is a sectional detail taken along line 10-10 in FIG.
21 and slightly enlarged;
[0018] FIG. 11 is an enlarged section taken from area encircled by
rectangular enclosure 12 in FIG. 2;
[0019] FIG. 12 is a fragmentary sectional elevation taken along
line 12-12 in FIG. 11;
[0020] FIG. 13 is a top plan view of the subject of FIG. 3 and
enlarged to show greater detail;
[0021] FIG. 14 is an enlarged fragmentary detail taken from the
rectangular enclosure 15 in FIG. 13;
[0022] FIG. 15 is an enlarged sectional elevation taken along line
15-15 in FIG. 9;
[0023] FIG. 16 is an elevational detail taken from the area
encircled by the rectangular enclosure 16 in FIG. 1;
[0024] FIG. 17 is an enlarged sectional detail with shallow depth
of field taken along line 17-17 in FIG. 16;
[0025] FIG. 18 is a fragmentary elevational detail taken along
18-18 in FIG. 2;
[0026] FIG. 19 is a fragmentary elevational detail view taken from
area enclosed by 19 in FIG. 18;
[0027] FIG. 20 is a fragmentary elevational detail view taken from
area enclosed by 20 in FIG. 18;
[0028] FIG. 21 is a fragmentary top plan view taken along line
21-21 in FIG. 19;
[0029] FIG. 22 is a fragmentary top plan sectional detail taken
along line 22-22 in FIG. 19; and
[0030] FIG. 23 is a fragmentary top plan section taken along line
23-23 in FIG. 20.
DETAILED DESCRIPTION OF THE INVENTION
[0031] A wind tower 10 is erected on a foundation 12 using multiple
levels 14, with each level 14 having a plurality, shown as
fourteen, of panels 16 that are separately cast and brought on site
for erection. The foundation 12 is typically of concrete, and
previous foundations have been huge, often six to twelve feet thick
and up to sixty feet square or in diameter. Existing foundations
may be used with this invention. As shown in FIGS. 1 and 17, the
first level 14 of concrete panels 16 must be secured to the
foundation 12. As shown, one suitable method is to use an anchor
bolt system such as from Williams Form Engineering Corporation
which employs long threaded anchor bolts 20 embedded in the
concrete foundation 12. Any suitable anchor method may be used to
anchor the first level of panels 16 to a foundation 12.
[0032] The first level of panels 16 are arranged on the foundation
12 to affix to anchor bolts 20 in the foundation. Each panel 16, as
shown in FIGS. 4-10, is a cast concrete panel that may include
steel reinforcing 18 and through which an all-thread post
tensioning system 22 attached to anchor bolts 20 is attached. As
shown in FIGS. 4-6, the panels 16 vary in width since each upper
level is smaller in diameter in the wind tower.
[0033] Each panel 16 has a corbel side end 26 that is enlarged and
forms the vertical joint between adjacent panels 16. An all-thread
post tensioning system 22 is in each panel 16 running vertically
with couplers 24 connecting each panel 16 at their horizontal
joints. The post tensioning system 22 as shown is available, for
example, from Williams Form Engineering Corp. and consists of an
all-thread bar, couplers, local zone reinforcing, washers and nuts.
The post tensioning system 22 may be threaded through the length of
the panels 16 via channels 34 formed in the concrete, with or
without metal or plastic corrugated ducts in the concrete of the
panels 16. The connection between horizontally adjacent panels 16
is shown in FIGS. 2, 4-10, 21-23. The corbels 26 allow thinner
flanges and better edge to edge alignment. Each corbel 26 may
include strengthening via reinforcing cabling 30 around vertical
reinforcing rods 32.
[0034] During assembly of the first level 14, several panels 16 are
erected and temporarily braced while being aligned and secured to
the anchor bolts 20. The first level panels may be quite large,
typically eight feet wide at the base and up to fifty-six feet in
height which is readily accommodated by trucks. With an eight foot
width, a typical 100 meter tower's first level can be 35 feet in
diameter. The upper ends of the panels 16 are preferably attached
to a wagon wheel system 40 in which a plurality of rods or beams 42
are attached at one end 44 to each panel 16 and radiate inwardly
like spokes of a wheel where they are secured together. As shown in
FIGS. 11 and 12, the spokes or beams 42 may be structural beams
such as I-beams in shape of simply steel members and are affixed to
a central hub 46. The wagon wheel system 40 ensures that each level
is secure adjacent its top and properly aligned prior to further
attachments.
[0035] As shown in FIGS. 13 and 14, the beam ends 44 may be bolted
via bolts 48 to the inner surfaces of each panel 16. Additionally,
FIGS. 18 and 19 shows that additional attachments may be made
between panels 16 at each corbel 26 with bent plates 50 and bolts
52. Finally, once the level is thus positioned, one or more
post-tensioning rings 58 may be positioned in corbel channels 60 as
best shown in FIGS. 20-23 and may be tensioned to provide increased
strength for each level. The ring 58 may be a wire strand or other
material for post tensioning around the inner periphery of the
assembled panels 16 in a level 14.
[0036] Each additional level 14 could be constructed as above;
however, ideally each succeeding level would be built at ground
level as per the first level other than attaching it to a
foundation. An on-site crane can then lift the next level up and
place it on top of the previous level. Each level is attached to
the other levels by the all-thread post tensioning system 22 such
that the upper levels are always locked to the lower levels. FIGS.
7-9 and 21 shows that each horizontal edge of the panels 16 may
include one or more mating alignment dimples 70 and protrusions 72.
When so included, a level being placed on top of a previously
assembled level may be positioned exactly where it is intended by
aligning the dimples 70 with the protrusions 72.
[0037] Construction of the wind tower 10 continues with the
addition of each new level. Typically, as many as seven levels may
form a wind tower. At the final, top level, a bolt pattern may be
included for attachment to the nacelle and mate with its bolting
pattern.
[0038] The construction of the wind tower 10 has many advantages.
The individual panels 16, while large at the lowest level are
readily transported on truck beds since their width is easily
handled by trucks. With a decreasing radius as the tower gains
height, each succeeding level has smaller, lighter panels meaning
that each new level is smaller and lighter than the last which
eases construction. The wagon wheel system 40 means that after each
level has been added the wind tower 10 is stable and construction
could stop for weather, strikes or other delays unlike conventional
wind towers which may not be structurally sound until completely
assembled.
[0039] The wagon wheel system 40 may be temporary and could be
removed after the next level is added, may be partially removed to
allow room for ladders and power cables or may be permanent. The
top level wagon wheel 40 may likewise be kept or partially or
completely removed after the nacelle is attached.
[0040] The trapezoidal shaped panels 16 are generally trapezoidal
in shape and preferably are flat or substantially flat which makes
them easier to fabricate and to transport. Although they could be
curved to simulate a round wind tower, each succeeding level will
be more complex in the required curves so a flat panel is
preferred.
[0041] While post tensioning is preferred, the height of the wind
tower could dictate changes in the post tensioning which may be
done as described or using any of the present systems for post
tensioning including those that use grout in the holes bearing the
cables.
[0042] The construction and tower as described herein also has the
benefit that a single panel could be replaced as needed in the
unlikely event of damage during construction from a crane, for
example. The concrete construction provides a wind tower with very
low deflection compared to steel. The thermal mass of concrete
towers is also better for heat than steel towers and avoids
convection of heat to the nacelle as is found in steel towers.
[0043] At each joint between levels or between corbels a
compressible sealant may be included (not shown) to avoid the need
to caulk any joints.
[0044] While this invention may be embodied in many different
forms, there are shown in the drawings and described in detail
herein specific preferred embodiments of the invention. The present
disclosure is an exemplification of the principles of the invention
and is not intended to limit the invention to the particular
embodiments illustrated.
[0045] This completes the description of the preferred and
alternate embodiments of the invention. Those skilled in the art
may recognize other equivalents to the specific embodiment
described herein which equivalents are intended to be encompassed
by the claims attached hereto.
* * * * *