US20140259667A1

US20140259667A1 - System, kit and method for surface repair and reconditioning of industrial sized fan blades such as incorporated into a cooling tower

Info

Publication number: US20140259667A1
Application number: US13/799,114
Authority: US
Inventors: James Witt; Stephen Witt
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-03-13
Filing date: 2013-03-13
Publication date: 2014-09-18

Abstract

A system, kit and method for non-structural surface repair and reconditioning of industrial sized blades includes an initial evaluation and power washing step for identifying required repairs. A surface cleaning step combines power washing with application of muratic acid and various mechanical tools and techniques for removing environmental and chemical buildup. A succeeding step provides for non-structural surface repairs to the blades, such as including filling and reshaping the leading edges with the use of an impact resistant urethane and/or a fast cure epoxy and fiberglass cloth. A finish coating step includes applying a chemically resistant and submersible grade (i.e. water resistant) top coat epoxy.

Description

FIELD OF THE INVENTION

The present invention relates generally to repair and reconditioning of blade assemblies associated with various applications. More specifically, the invention is directed to a system, kit and method for cleaning industrial sized blades and in which the repair and reconditioning process includes the cleaning of an entire blade surface combined with the post application of a chemical resistant and submersible grade topcoat epoxy.

BACKGROUND OF THE INVENTION

The prior art is documented with various examples of repair technologies applied to rotors, airfoil blades and the like. A first example of this is set forth in U.S. Pat. No. 8,091,227, to Hong, which teaches the repair and removal of erosion or impact damage using hand sandable elastomeric coatings on a curved substrate, including such as the leading edge of an airfoil, as well as specialized applicators and method of use.
Related publications US 2012/0163981 and 2012/015049, both also to Hong, each disclose a method and coating for protecting and repairing an airfoil surface such as a wing or rotor blade having a leading edge by a spray applied or prefabricated a variable thickness. A multi-layer coating system is also disclosed composed of a primer or adhesive layer, a basecoat layer and a topcoat where the coating is continuously tapering having a thicker cross section at the leading edge and a thinner cross section at the trailing edge of the airfoil.
Also disclosed in U.S. Pat. No. 8,901,229, to Deak et al. is a method of repairing subsurface defects in a shell member laminate of a wind turbine blade which includes detecting the location and boundary of the subsurface defect and drilling a fill hole from an external surface of the laminate into the defect proximate to a boundary of the defect. A vent hole is drilled from the external surface of the laminate into the defect proximate to an opposite boundary from the fill hole. A flowable bonding material is injected into the fill hole until the bonding material flows from the vent hole. The repair zone is reinforced with at least one mechanical fastener defined through the laminate either within the boundary of the defect or outboard of the boundary of the defect.

SUMMARY OF THE INVENTION

The present invention discloses a system, kit and method for effectuating non-structural surface repair and reconditioning of such as industrial sized cooling tower fan blades, such as in order to extend the service life of the blades by repairing inevitable damage from use resulting from impact, abrasion and environmental buildup. In an initial evaluation step, power washing with water is employed for identifying required repairs.
A successive surface cleaning step is employed combining power washing, muratic acid and various mechanical tools and techniques for removing environmental and chemical buildup (such as including buildup of loose surface materials). A succeeding step is employed for making non-structural surface repairs to the blades, such as including filling and reshaping the leading edges with the use of such as an impact resistant urethane. The surface and trailing edges can also be reconditioned using a fast cure epoxy and fiberglass cloth where necessary. A finish top coating step includes applying a chemically resistant and submersible grade (i.e. water resistant) epoxy or like suitable soft material.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1 is an environmental view of initial evaluation/power washing and successive surface cleaning steps;

FIG. 2 is an illustration of a leading edge repair step utilizing a filled impact resistant urethane;

FIG. 3 is complementary to FIG. 2 and additionally depicts a fast cure epoxy and fiberglass cloth at selected blade edge fill locations; and

FIG. 4 is an inverted view of a cooling tower fan blade in a finished condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As will be further described in further detail with reference to the following illustrations, the present invention discloses a system, kit and method for effectuating non-structural surface repair and reconditioning of such as industrial sized cooling tower fan blades, such as in order to extend the service life of the blades by repairing inevitable damage from use resulting from impact, abrasion and environmental buildup.
With reference initially to FIG. 1, an environmental view is generally shown at 10 of an initial evaluation/power washing step or operation applied to a standard industrial sized fan blade assembly, such as including a hub 2 with a plurality of outwardly and radially extending blades 4, 6, 8 et seq. In one non-limiting application, such an industrial sized blade assembly is typically integrated into a cooling tower and is susceptible to superficial damage such as chipping and crack formation resulting from rocks and other debris. It is also envisioned that the system, kit and method concurrently described in the present application can also be employed in the surface repairing of other blade constructions not limited to those depicted herein, and which can include any other industrial or commercial applications in which occasional or repetitive surface repair/reconditioning of the blades is desired.
In an initial evaluation step, a user is shown wielding a power washer (including wand 12 and conduit supply hose 14). In an initial evaluation step, the user applies pressurized water (see jet stream 16 which in one non-limiting variant can be directed at pressures of up to 3000 psi or greater) to the surfaces of each blade, such as in order to enable the user to identify required repairs.
Following high pressurized water power washing and initial evaluation, a surface cleaning operation is performed using a pressure sprayer such as depicted in FIG. 1 and to which a chemical solution including muriatic acid (also termed hydrochloric acid which is a highly corrosive mineral acid consisting of a clear colorless solution of hydrogen chloride in water) is attached for applying to the blade surfaces. At this point, the solution is allowed to sit for a period of time (such as 20 minutes in one non-limiting application), and following which the power washer is manipulated a second time to remove the composition and, typically, any undesirable chemical or other residue buildup.
Other tools can be provided at this stage and which can include a blade edged scraper 18 or sanding sheet 20 of specified grit, each being mounted in one application to an appropriately configured and long-handled tool or utensil, further at 22 and 24. Use of the tools is understood to be employed on an as-needed basis and in order to complete the cleaning operation by which it is desirable to remove any remaining environmental (including loose adhering materials remaining from the initial power washing or remedial muriatic acid cleaning steps) or chemical buildup by any such mechanical means.
Proceeding to FIG. 2, an illustration is shown of a succeeding leading edge repair step utilizing a settable material including, in one non-limiting application, a filled impact resistant urethane at locations 26 and 28 shown with respect to selected blade 4, and further at 30 with respect to selected blade 6. As further shown in FIG. 3, the surface and front/trailing edges of the blades can further be reconditioned using a fast cure epoxy and fiberglass cloth, as depicted at location 32 associated with blade 4 and further location 34 associated with blade 6 (see also additional urethane filled location 36 associated with opposite trailing edge of blade 4.
The filling of the leading/trailing edges and other surfaces of the blades 4, 6, 8 can be accomplished through the use of any suitable tools known in the art, such as including hand held shaping blades similar to those known in the application and forming of wall forming compound slurries and the like (e.g. drywall joint compound or mud), as well as any other tool which can facilitate application and shaping of a volume of formable material in an initially semi-viscous state, following which the material is permitted to set/dry. Additional tools, such as the scraper and/or sander depicted in FIG. 2, can also be employed in the smoothing or reshaping of the boundary established between the filler material and the original surfaces of the fan blades.
Referring finally to FIG. 4, a finish coating step includes applying a chemically resistant and submersible grade (i.e. water resistant) epoxy. This is shown by industrial sprayer 38 applying a stream 40 of aerated/atomized material to the cleaned and resurface blades 4, 6, 8.
In one repair protocol, the leading edges of the blades are filled and reshaped with the impact resistant urethane, with the surface and trailing edges likewise being filled with the fast cure epoxy and fiberglass cloth, where necessary. That said, it is understood that the present invention contemplates any repair protocol or combination using any arrangement of urethanes, epoxies or other settable compounds which can assist in the surface repair/reconditioning of the fan blades.
A method for effectuating surface repair of a blade includes the steps of power washing power the blades with water in order to identify required repairs, filling and reshaping at least one of leading and trailing edges of the blades with a settable material and applying a finishing coat of a chemically resistant and submersible grade epoxy. Additional steps include applying muratic acid using a pressure sprayer following power washing of the blade.
Other steps include applying a second power washing step following application of the muratic acid, as well as scraping or sanding following the second power washing step and in order to remove any remaining environmental or chemical buildup. Additional steps include the filling and reshaping of at least the forward and trailing blade edges utilizing either of an impact resistant urethane or a fast cure epoxy and fiberglass cloth. The present invention further contemplates corresponding a kit and associated system for surface repair and reconditioning of the fan blades and which utilizes similar materials and procedures as employed with the above-described method.
An objective of the present system, method and kit is to extend the service life of the blades by repairing damage from any combination of impact, abrasion and/or environmental buildup. The present invention further enables this to be accomplished with a fraction of the cost of blade replacement. Additional advantages include the ability to complete minor structural repairs and surface reconditioning to the blades both on-site and with very short downtime.
Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims.

Claims

We claim:

1. A method for effectuating surface repair of a blade, comprising the steps of:

power washing the blade with water in order to identify required repairs;

filling and reshaping at least one of leading and trailing edges of the blade with a settable material; and

applying a finishing coat of a chemically resistant and submersible grade epoxy.

2. The method as described in claim 1, further comprising the step of applying muratic acid using a pressure sprayer following power washing of the blade.

3. The method as described in claim 2, further comprising a second power washing step following application of the muratic acid.

4. The method as described in claim 3, further comprising at least one of scraping or sanding following said second power washing step and in order to remove any remaining environmental or chemical buildup.

5. The method as described in claim 1, the step of filling and reshaping the blade edges further comprising applying an impact resistant urethane.

6. The method as described in claim 1, the step of filling and reshaping the blade edges further comprising applying a fast cure epoxy and fiberglass cloth.

7. The method as described in claim 1, said step of power washing further comprising pressurizing water to at least 3000 psi.

8. A kit for surface repairing and reconditioning of industrial sized fan blades, comprising:

a power washer for delivering a pressurized water source to the blades in order to assist in identifying required repairs;

a set of tools for filling and reshaping at least one of leading and trailing edges of each blade with a settable material; and

a chemically resistant and submersible grade epoxy applied as a finishing coat over the blades.

9. The kit as described in claim 8, further comprising muratic acid applied to the blades using a pressure sprayer following power washing of the blade.

10. The kit as described in claim 8, further comprising at least one of a scraper or a sanding/abrading medium for removing environmental or chemical buildup upon the blades.

11. The kit as described in claim 1, the settable material further comprising applying an impact resistant urethane.

12. The kit as described in claim 1, the settable material further comprising a fast cure epoxy and fiberglass cloth.

13. A system for surface repairing and reconditioning of industrial sized fan blades, comprising:

providing a power washer for delivering a pressurized water source to the blades in order to assist in identifying required repairs;

utilizing a pressure sprayer applying a muriatic acid to the blades using a pressure sprayer;

applying a set of tools for filling and reshaping at least one of leading and trailing edges of each blade with a settable material; and

applying a chemically resistant and submersible grade epoxy as a finishing coat over the blades.

14. The system as described in claim 13, further comprising providing a second power washing operation following application of the muratic acid.

15. The system as described in claim 14, further comprising at least one of scraping or sanding following said second power washing and in order to remove any remaining environmental or chemical buildup.

16. The system as described in claim 13, the reshaping at least one of leading and trailing edges of each blade further comprising applying an impact resistant urethane.

17. The system as described in claim 13, the reshaping at least one of leading and trailing edges of each blade further comprising applying a fast cure epoxy and fiberglass cloth.