This application incorporates by reference herein Ser. No. 12/611,305, entitled “Apparatus and Method for Lining Large Diameter Pipe with an Environmentally Compatible Impervious Membrane” filed Nov. 3, 2009, and now U.S. Pat. No. 7,726,256. This application also incorporates “Method and Apparatus for Lining Pipes with Environmentally Compatible Impervious Membrane” by reference, Ser. No. 12/476,983 filed Jan. 2, 2009 and now U.S. Pat. No. 7,591,901.
1. Field of Invention
This disclosure pertains to the distribution of drinking water within existing piping systems in buildings and structures. With general infrastructure within the US and around the world in a precarious state of decay it has been the object of many to provide for a cost effective method to perform in situ-rehabilitation of these properties. In the global arena, water distribution systems are seriously compromised with failures creating community disturbances, commercial loss and environmental incidents. In the industrial sector, pipe and transmission lines carrying volatile and dangerous or hazardous materials are constantly at risk of failure due to age, neglect or lack of funds to replace or repair with traditional methods.
This disclosure permits the lining of potable water pipes in situ in commercial and residential buildings with no adverse affects to human occupants. The disclosure eliminates the “remove and replace” method of rehabilitating water distribution systems. This eliminates the disruption of old existing asbestos insulation and removal of lead painted walls. Avoiding the distribution of these known carcinogens and toxic substances is of great value to the workers and building occupants and the environment. In addition the method of the disclosure installs lining (and thereby isolates) lead soldered joints of water piping systems. This eliminates further contamination.
The NSF/ANSI 61-2010 standard approves lining of water distribution pipe systems utilizing electrically charged lining material that are attract to and adhere to the pipe wall during the lining process due to the fact that the pipe system has been electrically grounded. This method eliminates the chance of the lining not encapsulating every surface of the pipe wall.
2. Description of Related Art
Prior art demonstrates numerous methods to rehabilitate pipelines, conduits and passageways from the inside in order to restore asset integrity.
Removal of pipes is unsatisfactory since it often creates dispersion of asbestos dust or lead paint. In situ relining of small diameter pipes following convoluted paths is greatly preferable and environmentally non-hazardous.
The invention pertains to a lining device that can be pulled through a pipe having an approximate diameter between 0.750 inches and 36 inches. The device sprays an electrically charged lining mixture 360° onto the inside pipe surface. The lining mixture is electro-statically charged to facilitate full encapsulation and adhesion to all pipe wall surfaces in a circumferentially uniform thickness.
The lining material can be premixed an conveyed to the device through a heated, non-expanding hose. The heating maintains a low viscosity. The heated hose may be contained in an umbilical also conveying an electric cable, a CCTV cable and pressurized air hose. The umbilical may also contain an insulated chilled nitrogen hose. The nitrogen may be exhausted into the atomized pipe lining material to increase lining build up.
The lining device can be contained in a multipart housing having flexible rod-like components that hold the device in the center of the longitudinal axis of the pipe. The lining device can be pulled through at least a part of a building or structure potable water distribution pipe system comprising straight pipes and multiple 1 to 90 degree bends, tees and multiple diameters.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention. These drawings, together with the general description of the invention given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
The invention pertains to a lining device that can be pulled through a pipe having an approximate diameter between 1 and 36 inches. The device is connected to an umbilical at a second ported assembly body. The umbilical conveys pipe lining material to the device. The lining hose within the umbilical is heated and non-expanding. This allows the lining to be mixed at a remote location and pumped under pressure to the dispenser apparatus. The second ported assembly body (“second housing”) conveys the lining mixture into two branches that are conveyed to a first front end of a first ported body assembly (“first housing”). The multi-part housing connected with flexible hose allows the apparatus to navigate tight turns in the pipe. The lining mixture passes over wave/pulse generation tabs mounted within the two lining annulus of the first housing.
Due to the small size of the apparatus having the ability to traverse 90° angle, the lining apparatus can be installed into the piping system through existing accesses in the municipal drinking water and fire protection/deluge sectors. Accesses such as clean out, valves and hydrants can be used. Prior art epoxy lining devices and other method all require excavation of large areas and the cutting open of the pipe to access for installation of lining devices. This creates a huge environmental impact as the earth, existing foliage, roads, sidewalks, etc. have to be torn up to facilitate access. These excavations can also create traffic delays.
The liner is dispersed from two exit ports (“trajectory/static charging orifices”) extending from the second back end of the first housing in a stream that strikes a rotational drive receptacle mounted in a dwell cone. The exit port is dimensioned to emit the pressurized lining at a predetermined angle so that the force of the emitted liner rotates the rotational drive receptacle and dwell cone at a high rate of speed. The rotational drive and dwell cone rotate together on a rotating shaft. The shaft turns on bearings within the first housing. The shaft has a reciprocating motion as well as a rotational motion.
The juncture of the rotational drive receptacle and the dwell cone form a pocket shape or space. The liquid liner flows across the surface of the rotational drive receptacle to the pocket. The liner material has an opportunity dwell within the pocket and where the curing process can continue. The liner material is pulled by centrifugal forces up the side wall of the dwell cone to the knurling edge. The device disperses the lining 360° around the interior wall of the pipe.
Connected to the rotating shaft within the first assembly body is an internal air assist component. It comprises a two function turbine. It assists in initially rotating the shaft as the trajectory/velocity of the fluid from the trajectory/static charging orifices is slow in initiating rotation of the dispersion cone. The rotation of the dispersion cone is assisted with air flow from the air driven turbine. The air assist turbine is powered by a compressed air hose included with the umbilical. The air turbine assist mechanism facilitates creating the initial rotation of the shaft in that it cohesively provides, in conjunction with the energy of the fluid stream, the initial energy necessary to expedite the shaft to immediately achieve full RPM necessary to disperse the liner 360° around the pipe surface. The second function is the turbine creating a venturi effect. The turbine is encapsulated within the first housing. The turbine is mounted in a bore configuration that when the turbine spins it utilizes the exhausting air to create a venturi effect. This venturi effect pushes high volumes of the exhaust air backwards and subsequently out of the first housing at the bottom. This air is then utilized to remove debris in the path of the housing dispersing the lining as the housing traverses backwards (pulled by the umbilical or tether). The air assist component creates a cleaning mechanism for the pipe to be lined. The turbine blades are flat and almost vertical to the bearing with sufficient slope to create a directed exhaust flow while not sacrificing torque.
For smaller diameter pipe, i.e., ¾ inch, the device can operate without a dwell cone and rotating shaft. This is advantageous due to the size of the rotating dwell cone and proximity to the pipe wall. Instead, the lining material is dispersed from a combination liquid spray orifice and air sprayer orifice. The air from the air sprayer orifice atomizes the liquid lining. The fine spray charged particle lining is immediately attracted to the pipe wall surface.
In another embodiment, the invention discloses a two stage nitrogen process. There will be a designated hose in the umbilical that will deliver nitrogen from a pressurized tank to the remote apparatus. The first part of this is to cool the product immediately prior to spraying. As disclosed, the mixed lining material is conveyed to the apparatus in a heated hose to lower the viscosity of the product to provide the ability to pump it over 600 feet. This in turn makes the product thinner when it is being sprayed and not allow for high build up. The product cure time may be delayed. The nitrogen hose will be separated from the heated hose in the umbilical via insulation until the very end of the umbilical within a 12 inches from the apparatus. The nitrogen hose will then coil around the fluid hose to cool the heated product prior to dispersion. This will raise the viscosity therefore increasing the liner build up that can be achieved on the pipe wall. The second function of the nitrogen stream is that when it is exhausted at the end of the coil it in effect dispenses all oxygen from the area making the unit intrinsically safe.
The umbilical attached to the second housing also contains an electrical cable. Further, the umbilical can contain a CCTV cable to allow utilization of a television camera on one of the housings.
The mounted to the first and second housing are a plurality of centering components (prongs or bristles) protruding from the ported assembly housings. These components function to maintain the housing in the center of the pipe's longitudinal axis. The multi-prongs also maintain the apparatus within the center axis of the pipe. This is particularly useful as the apparatus is pulled through corners and bends of the pipe. It will be appreciated that the prongs have flexibility and can maintain the center position of the apparatus in differing diameter pipes. The prongs are superior to prior art methods that use flexible or spring loaded arms radiating from the housing at 90 or 120 degree intervals. These prior art devices can not traverse a short radius 90° pipe bend or elbow. The angle to too acute and the flexible or collapsible arms would jam in the bend. (Such devices are only suitable for traversing long radius bends.) Unfortunately, short radius elbow and tees are used in standard building water distribution piping systems. Secondly the prior art would to get caught up/stuck at any coupling fittings within these pipes. The system of the present disclosure allows for dispersion dwell cone centering in any of the aforementioned configurations.
As stated, the lining component does carry an electrical charge after flowing through the conductor or folic orifice(s). The charge can be imparted in the liner by passing the lining flow through a positively charged wire or conductor orifice prior to the stream being emitted from an exit port. The charged stream is attracted to the grounded pipe wall. It will be appreciated that the pipe wall will have a negative charge. The lining will be positively charged and electrically attracted to the interior pipe wall, thereby facilitating improved bonding of the liner to the pipe wall. The adhesion of the positively charged liner to the negatively charged pipe surface also facilities the holding of the liner without sagging during cure. Additionally, the positive charged liner encompasses all microscopic profiles and undulations in the pipe wall surface due to this inherent attraction irrespective of their initial configuration or placement.
A method and apparatus is disclosed for the remote and robotic in situ or facility installation of an organic, monolithic pipe liner. The liner is electro-statically applied. The liner is approved for potable water. The liner may be a polyurea. The lining may provide structural reinforcement of the pipe. The method and apparatus allows installation of lining through convoluted pipe systems with internal diameters ranging from 1″ to 36″.
In regard to high rise building applications, use of polyurea lining has a high elongation. Current method utilize epoxies that have very low elongation and are brittle. The epoxies are prone to crack when they are subjected to thermal cycling and or pressure ‘slams’ that originate from turning on and off pressurized pipe systems, e.g. faucets, etc. The polyurea lining material is better suited for water pipe lining systems.
The wave pulse generation tabs are semi flexible inserts that are attached to the interior of the port assembly inside the first ported body assembly. The wave/pulse generation tabs afford a wave effect by creating a vortex in the product flow in each trajectory/static charging orifices. This vortex results in millisecond undulations or “flutters” of the lining flow in each trajectory/static charging orifice. This fluttering dissipation of the lining flow from the trajectory/static charging orifice as it impacts the rotating drive receptacle creates an interconnected horizontal reciprocating pulsing motion in the shaft, the rotating drive receptacle and dwell cone. This pulsating motion is then significantly magnified by the reciprocation wave spring washers encompassed around the shaft and seated in the ported body assembly. The reciprocation wave spring washers creates an inertia in the shaft linear to the fluttering impact energy being exerted on the rotating drive receptacle from the product streams out of the trajectory static charging orifices. In one embodiment, this reciprocating motion may be between 0.125 inch and 0.250 inch. This reciprocation allows for a more uniform distribution of the material off of the dwell cone in turn affording higher product flows without resulting in drips or sags in the lining.
It will be appreciated that the rotational drive receptacle and dwell cone rotate together as the pressurized lining mixture is emitted from the trajectory/static charging orifices.
The heated lining hose enters the first front end of the second ported body assembly 105. Within the assembly body, the lining mixture is branched into two lines flowing to the first ported body assembly 110 through tubes 111, 112 connected to the inflow fittings. The delivery hose is heatable and non-expanding. The liner is delivered with pressure.
Also illustrated in
The combination dwell cone and the rotational drive receptacle are mounted on the free spinning rotary shaft. Both the dwell cone and the rotational drive receptacle are pressed up to a machined shoulder of the shaft and retained on the shaft with the retaining nut. The rotational drive receptacle has a pressed bearing to receive the shaft. The cone receives the fluid flow of the liner being cast centrifugally of the rotational drive receptacle and allows the lining mixture dwell time needed to cast the material in a consistent flow circumferentially. It is machined with atomization knurling at the edges circumferentially to allow the dissipation and atomization of the polyurea lining material in microscopic droplet form.
In one embodiment, the lining mixture comprises isocyanate and amine terminated resin. This mixture forms a polyurea lining. The lining mixture can be mixed at a pump located proximate to the pipe access. The lining may be heated while conveyed through the hose to the lining device. This will maintain a low viscosity. The lining mixture can include quaternary ammonium ethosulfates, ethoxylated amines or glycerol esters. These additives facilitate the addition of a positive charge within the lining mixture by the static charge conductor plate. This draws the charged lining particles to the negatively charged (grounded) pipe wall surface. This electrostatic attraction force holds the lining material tightly to the pipe wall during cure and without drips or sags. The polyurea lining may not have an accelerated cure time.
This specification is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and described are to be taken as the presently preferred embodiments. As already stated, various changes may be made in the shape, size and arrangement of components or adjustments made in the steps of the method without departing from the scope of this invention. For example, equivalent elements may be substituted for those illustrated and described herein and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
While specific embodiments have been illustrated and described, numerous modifications are possible without departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.
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