The invention relates to a device and system for coating pipes and ducts. In particular, the device of the invention utilizes a duct coating applicator capable of navigating small ducts and is used with a system that provides data to an operator and to a remote recipient.
There are numerous patents and publications describing devices and systems purporting to inspect, repair, and seal pipes and ducts. However none of these devices and systems can navigate and treat small (e.g., 6 inch in diameter) HVAC ducts with elbows and transitions. In addition, none of these devices have been packaged in systems that enable regional and national franchising. This disclosure describes a device and system to meet the objectives.
The duct coating system uses a self-propelled remotely operated tracked or wheeled vehicle (ROV) to conduct initial and final inspections and to video record those inspections of a duct interior. Preferably, a camera is also placed on the applicator head of the duct coating applicator to monitor the coating process and to track the location of the application head. This is particularly important when applying additional coats of material at specific locations in a duct.
The applicator of the duct coating system is preferably passive, i.e., towed. The duct coating applicator may be provided with a scissor-type carriage or, alternatively, may be mounted on an ROV similar to the inspection ROV to position the nozzle and to assist the capstan or winch in propelling the duct coating applicator through the duct.
The ROV may also be used to string a tow line through the duct to be attached to the applicator head. The tow line is used to pull the applicator head and material supply lines through the duct prior to coating the duct. The duct coating applicator of the invention is preferably a towed device that conveys a dynamic mixer for plural compounds, and a metering nozzle capable of uniformly coating the inside of the duct/pipe. The duct coating applicator can transport a single component nozzle for priming the duct, cameras for inspecting the duct, and devices to scarify the walls of the duct. The duct coating applicator can also convey an orientable nozzle to repair holes in the duct by injecting plural fluid compounds into cavities.
The plural fluid nozzle and transporter works as follows. The duct coating applicator consists of a cylindrical body to which are attached four 4-bar extendable arms with wheels. These arms can extend or contract to follow the inside of a duct or pipe while positioning the body in the center of the duct. An annular air cylinder contracts or extends the arms. The cylinder is counterbalanced by a set of extension springs to control the forces exerted by the wheel against the wall of the duct. In an alternative version, springs extend the arms and arms are contracted manually.
The duct coating system of the invention is a three fluid system, e.g., air, resin, and, in the case of polyurea, isocyanate. Preferably, the flow rates of each pump of the resin and isocyanate may be separately controlled because of the large ranges in viscosity of the two materials as a function of temperature. The two parts of the plural fluid are metered separately into the rear of the nozzle system. The two parts of the fluid are combined by impinging the two streams. Further mixing occurs in the slotted or round orifices. An adjustable nozzle produces a cone shaped pattern or radial fan shaped pattern of the mixed materials to coat the inside of the duct. Viscosity is controlled by resistance heaters (not shown). The transporter is towed through the duct by its supply hoses with speed controlled by a capstan (not shown). Servos controlled by a central computer drive the capstan plural fluid pumps, transporter arm, heaters, and other devices in the system. The system of the invention is capable of conveying a nozzle through HVAC ducts of a variety of sizes. The system facilitates mixing, atomizing, and applying plural compounds to seal and provide structural integrity to the duct. The duct coating system provides a means to inspect, clean, prepare, prime, coat, and document the sealing process. The system also provides a means to repair and disinfect a duct/pipe installation.
The duct coating system includes the capacity to transmit to a franchiser and franchisee statistics obtained during the sealing of a duct system in a home. This feature provides for the ability for automated accounting and billing for a franchisee and franchiser.
Referring now to
Slotted member 48 is located in slotted core mixer 46 adjacent to an outlet end of impinging mixing chamber 44.
Outlet cap 52 is threadably received on outlet end 28 of core member 16. Outlet cap 52 receives stem 54 that defines exit passageway 56.
Adjustable nozzle 58 is positioned on an outlet end of stem 54 for dispersing fluids traveling through exit passageway 56.
Inlet member 62 is affixed to inlet end 18 of cylindrical body 12. Inlet member 62 defines first threaded inlet 64 and second threaded inlet 66. First threaded inlet 64 communicates with inlet 34 of first longitudinal passageway 30. First threaded inlet 64 receives a first component of a plural fluid. Second threaded inlet 66 is in communication with second inlet 36 of second longitudinal passageway 32. Second threaded inlet 66 receives a second component of a plural fluid.
Slider 68 is slidably received on and surrounds outer member 14. Slider 68 interacts with annular piston 24 for being longitudinally displaced thereby.
First pair of extension arms 70 has a first arm 72 having a proximate end 74 pivotally affixed adjacent to inlet end 18 of cylindrical body 12. First pair of extension arms 70 has a second arm 76 having a proximate end 78 pivotally affixed to extension slider 68. First arm 72 and second arm 76 of first pair of extension arms 70 are pivotally affixed to one another at point 80 located approximately at a midpoint of each of first arm 72 and second arm 76.
First wheel 82 is affixed to a distal end of first arm 72, and second wheel 86 is affixed to a distal end of second arm 76 of first pair of extension arms 70. First extension spring 90 has a first end affixed to outer member 14 and a second end affixed to extension slider 68 for biasing extension slider 68 toward inlet end 18 of cylindrical body 12, thereby biasing first wheel 82 and second wheel 86 away from cylindrical body 12 via scissor action of first arm 72 and second arm 76.
Second pair of extension arms 92 has a third arm 94 having a proximate end 96 pivotally affixed to inlet end 18 of cylindrical body 12. Second pair of extension arms 92 has a fourth arm 98 having a proximate end 100 pivotally affixed to extension slider 68. Third arm 94 and fourth arm 98 of second pair of extension arms 92 are pivotally affixed to one another at point 102 located approximately at a midpoint of each of third arm 94 and fourth arm 98. Third wheel 104 is affixed to a distal end of third arm 94 and a fourth wheel 108 is affixed to a distal end of fourth arm 98 of second pair of extension arms 92.
A third pair of extension arms 114 has a fifth arm 116 having a proximate end 118 pivotally affixed to inlet end 18 of cylindrical body 12. Third pair of extension arms 114 has a sixth arm 120 having a proximate end 122 pivotally affixed to extension slider 68. Fifth arm 116 and sixth arm 120 of third pair of extension arms 114 are pivotally affixed to one another at point 124 proximate a midpoint of each of fifth arm 116 and sixth arm 120. Fifth wheel 126 is affixed to a distal end of fifth arm 116 and sixth wheel 130 is pivotally affixed to sixth arm 120 of the third pair of extension arms 114.
Second extension spring 134 (
A fourth pair of extension arms 136 has a fifth arm 138 having a proximate end 140 pivotally affixed to inlet end 18 of cylindrical body 12. Fourth pair of extension arms 136 has a sixth arm 142 having a proximate end 144 pivotally affixed to extension slider 68. Fifth arm 138 and sixth arm 142 of fourth pair of extension arms 136 are pivotally affixed to one another at point 146 proximate a midpoint of each of fifth arm 138 and sixth arm 142. Fifth wheel 148 is affixed to a distal end of fifth arm 138 and sixth wheel 152 is pivotally affixed to sixth arm 142 of the fourth pair of extension arms 136.
Referring now to
The duct coating applicator 10 may be of the type disclosed in U.S. patent application Ser. No. 12/723,425 entitled “Mixing Nozzle for Plural Component Materials,” which is hereby incorporated by reference.
Referring now to
First resin tank 308 is provided for receiving a quantity of a first resin. First reservoir 310 is in communication with and receives resin from first resin tank 308. First reservoir temperature sensor 330 is provided to read temperature of the resin in first resin tank 308. First temperature sensor 330 communicates temperature data with controller 302. First temperature indicator 312 is provided on controller 302 for indicating temperature of the resin in first resin tank 308.
First pump 314 communicates with first resin tank 308 for receiving resin therefrom. First resin supply line 316 is provided for receiving resin from first pump 314 and for delivering resin to duct coating applicator 10. First resin pressure sensor 318 communicates with first resin supply line 316 for measuring pressure in first resin supply line 316. First resin pressure sensor 318 communicates pressure data to controller 302. First resin supply pressure indicator 320 indicates the pressure readings of second resin pressure sensor 318 as instructed by controller 302.
Second resin tank 328 is provided for receiving a quantity of a second resin. Second reservoir 311 is in communication with and receives resin from second resin tank 328. Second reservoir temperature sensor 331 is provided to read temperature of the resin in second resin tank 328. Second temperature sensor 331 communicates temperature data with controller 302. Second temperature indicator 332 is provided on controller 302 for indicating temperature of the resin in second resin tank 328.
Second pump 334 communicates with second resin tank 328 for receiving resin therefrom. Second resin supply line 336 is provided for receiving resin from second pump 334 and for delivering resin to duct coating applicator 10. Second resin pressure sensor 338 communicates with second resin supply line 336 for measuring pressure in second resin supply line 336. Second resin pressure sensor 338 communicates pressure data to controller 302. Second resin supply pressure indicator 340 indicates the pressure readings of second resin pressure sensor 338 as instructed by controller 302.
Duct diameter proximity sensor 342 is provided on duct coating applicator 10 for measuring a diameter of duct 11 through which duct coating applicator 10 is traversing. Duct diameter proximity sensor 342 is in communication with controller 302.
Video camera 344 is located on duct coating applicator 10. Video display 346 is provided for receiving video signal from video camera 344 on duct coating applicator 10 via a data signal cable 348. Video recorder 350 is in communication with video display 346 and with data signal cable 348.
Winch 352 engages first resin supply line 316, second resin supply line 336 and data signal cable 348 for pulling duct coating applicator 10 through duct 11. Carriage variable speed drive 354 is in communication with winch 352 for directing a speed with which winch 352 pulls duct coating applicator 10. Carriage variable speed drive 354 receives a carriage speed signal 356 from controller 302.
A remote jobs statistics collection computer 358 is provided at a location remote from duct coating applicator 10 and controller 302. An external communicator, such as cell modem 360, is in communication with controller 302 for passing job statistics to remote jobs statistics collection computer 358.
Referring now to
The overall methodology of the controller 302 is that of a feed forward system. In
In operation of the present embodiment, a signal from the pump speed setting 304 is summed with a GFF
The flow rate signal Kflow is summed with the duct diameter as Kdia, which follows the equation Kdia=−Q/πD2ssvss. Here Q is the volumetric flow rate. Hence, to maintain a constant coating thickness T, the volumetric flow rate Q must remain in proportion to the product of the diameter squared and the velocity. In the present system, the actual measured duct diameter is reported to the controller 302 by the duct coating applicator 10. This measurement is scaled by a feed forward gain factor GFF
In producing a thickness of coating T, Kflow and Kdia are summed with Kcarr or Kcarriage which follows the following equation: Kcarr=−1/πDssv2ss. Kcarr is a carriage speed signal from the controller 302. Thus it will be appreciated that carriage speed, as relating to thickness T, is directly proportional to volumetric flow and inversely proportional to diameter and velocity. The final thickness T may be computed from the system using the equation T=Q/πDv.
Based on the foregoing, it will be appreciated that in operation both the pump speed and carriage speed may be controlled by the controller 302 to produce a uniform and desired coating thickness T. In the present embodiment, the carriage speed signal is produced by the controller 302 and fed to duct coating applicator 10. The pump speed is derived based upon the carriage speed to produce the proper flow rate for the desired thickness. Since the speed is controlled by controller 302 it will be known (assuming adequate traction and correct mechanical operation of the controller 302) and can be fed into GFF
Through the feed forward mechanisms just described, combined with user inputs, controller 302 controls the pump speed and carriage speed to create the desired thickness T of the applied coating. It will be appreciated that controller 302 must have the correct forward gain factors GFF
The controller 302 may be implemented in hardware, software, or a combination. A graphical interface could be designed that allows a user to enter parameters and to start and stop the operation of the duct coating applicator 10. In other embodiments, a selection of switches and dials may be arranged on a control box. In this case, a user may dial in or select for parameters and modes of operation. The underlying control hardware could be a general purpose microcontroller, an application specific integrated circuit, or various computers on a chip that may also incorporate I/O ports for sending the control signals to the duct coating applicator 10.
Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.
This invention was made with U.S. Government support under grant number NSF Grant No. EEC-0332723 awarded by the National Science Foundation. The Government has certain rights in this invention.