REHABILITATION SYSTEM FOR PIPES
Description of the Invention FIELD OF THE INVENTION The present invention is directed to the rehabilitation of existing pipelines, which carry crude oil, refined petroleum products, natural gas or water.
BACKGROUND OF THE INVENTION A pipe typically has an outer coating to protect it from corrosion and other harmful effects, particularly when the pipe is buried underground. Underground pipes are commonly used throughout the world to transport various materials from one location to another and they are provided in most cases with a protective coating at some time before being buried. This coating degrades with time and, if the pipe itself is to suffer additional permanent damage, the pipe must be dug up, the old coating must be removed, the surface of the pipe must be conditioned and a new coating of material Protector must be applied to the pipe. In a typical pipeline rehabilitation operation, the pipeline will be discovered, and a lifting or lifting mechanism, such as a crane, will be used to lift the exposed portion of the pipeline from the trench and rest the exposed pipeline on skids or girders. seat to provide access to the entire outer surface of the pipe in the portion between the skids. The pipe must then be cleaned, the outer surface of the pipe must be prepared to receive a new protective coating, and then the pipe must be coated. However, it should be noted that a pipeline can also be rehabilitated while it is in the trench after excavation. Initially, handwork was required to remove the old coating with hand tools such as scrapers. This technique is obviously time consuming or time consuming and quite expensive. Several attempts have been made to provide more automation to the cleaning process, including those included in U.S. Pat. 4,552,594 ('594) granted on November 12, 1985 to Van Voskuilen, U.S. 4,677,998 ('998) granted on July 7, 1987 to the same inventor, U.S. 5,085,016 (? 16) granted on February 4, 1992 to James L. Rose, U.S. 5,359,748 ('748) granted on November 1, 1994 to Thomas J. Etheridge, U.S. 5,626,438 ('438) granted on May 6, 1997 to the same inventor, and U.S. 6,626,376 ('376) granted on September 30, 2003 to James L. Rose. The '594 and' 998 patents disclose the use of high pressure water jets, which are moved in a zigzag path along the surface of the pipe to be cleaned to detach the coating. The '016 patent discloses a self-propelled sliding housing or carriage adapted to be easily assembled on a tube to move along it. The sliding carriage includes a upper center body section on the upper surface of the tube and two opposite side sections hinged to the upper section for outward swing or for pivotal movement in an open position for lowering over the pipe. Upon contacting the central body section with the pipe or tube, the two side sections are pivoted downwardly around the pipe and bolted to the upper section of the sliding carriage supported on the pipe for self-propelled movement along the pipe. The '748 patent discloses a self-propelled carriage assembly, which is mounted on a pipe to remove the deteriorated coating formed therein. The self-propelled car assembly includes a frame having first and second sections. The first section is positioned above it is detachably connected to the second section to facilitate its placement and removal of the pipe. Front and rear rollers are attached to the upper section of the frame to support the carriage assembly for movement along the pipe.
A motor is operatively or functionally associated with at least one of the front or rear rollers to drive them. A first pulley or drive wheel is mounted in the upper portion of the frame, so that when the carriage is placed in the pipe, the first pulley is disposed above the pipe. A second pulley or drive wheel is mounted in the lower portion of the frame, so that when the carriage is positioned in the pipe, the second pulley is arranged below the pipe. The first pulley is offor misaligned from the second pulley along the longitudinal axis of the pipe. A first endless flexible member travels below the outer surface of the pipe and on the first pulley or drive sprocket at a high speed to remove the deteriorated protective coating from the upper half of the pipe. A second endless flexible member passes over the pipe and under the second pulley or drive sprocket at a high speed to remove the damaged coating from the lower half of the pipe. More specifically, the first and second endless flexible members form first and second closed loops or turns, respectively, around the pipe. The first turn passes under the bottom surface and along the side surfaces, while the second turn passes over the top surface and along the side surfaces of the pipe. Hydraulic cylinders may be associated with each of the first and second pulleys to allow an independent adjustment of the tension of the first and second turns. The '438 patent discloses a system for excavating and rehabilitating underground pipes. The system includes a soil removal unit, a coating removal unit and a defect detection unit, each of which is self-propelled to travel on and along the underground pipeline. The soil removing unit includes a usable housing adapted to be mounted around an exposed portion of the underground pipe. The soil removal unit also includes front and rear wheel assemblies adapted to couple the upper surface of the underground pipe. A plurality of endless belts or bands are suspended from the housing, so that they assume a position below the underground pipe. The endless belts are operable or functional independently and include a plurality of cutter / excavator elements. The endless belts are misaligned in both horizontal and vertical directions with respect to the underground pipe. The coating removal unit includes at least one endless chain to remove the damaged coating from the underground pipe. The defect detection unit automatically detects defects in the outer surface of the underground pipe as it moves along its entire length. The '376 patent discloses a self-propelled aerosol coating device for coating or coating a pipe, which is supported on the pipe and travels longitudinally along the pipe. A pair of generally semicircular arms is mounted on opposite sides of the pipe to surround the pipe with each arm having radially spaced internal and external guides. A nozzle carriage is mounted on each arm for reciprocal movement arched about 180 degrees along the internal and external guides. A motor member or endless actuator is mounted on each arm and extends along the length of the arched arm. A motor connection is provided between each carriage and the associated endless and flexible motor member to connect the motor member in driving relation to the carriage. The motor connection is effective at the ends of the arm to transfer the driving or actuating force for the car, between internal and external races of the endless motor member, in order to allow a continuous movement of the endless motor member in one direction for the full travel cycle of the carriage. The endless flexible motor member preferably comprises a chain mounted on sprockets at the ends of the arm for continuous movement of the chain in one direction. Each carriage has rollers to travel along the radially spaced internal and external guides on the associated arm. The system for excavating and rehabilitating underground pipelines of the '438 patent comprises a specialized earth removal unit incorporating an expensive design, an external defect detecting unit, which is now obsolete and not used anymore, and which can not be portable for provisional assembly / disassembly procedures in the field as the present invention does. These and other disadvantages are solved by the present invention. A variety of methods and devices have been proposed and implemented to excavate an underground pipeline and restore the deteriorated coating formed on it. Although some devices of this type have been an improvement over the prior art, there is still a need in the industry for improved operation in the cleaning and coating operation. It is toward this objective that the present invention is directed. SUMMARY OF THE INVENTION The present invention is directed to the removal or removal of rust on uncovered rusty or rusty pipes or tubes, to the cleaning of the exterior of the pipe or pipe and to the coating of the exterior of the pipeline either in the trench, at along the sides of the trench or on the ground. It also addresses the removal of an existing exterior coating and / or rust or rust on the pipes, cleaning the exterior of the pipe and coating the exterior of the pipe either in the trench, along the sides from the ditch or on the ground. The new system of the present invention is to remove the outer coating and / or the rust by means of a manual sandblasting equipment and to coat the exterior of the pipe by means of a manual spray gun. The current system limits the daily work output completed, in 8 hours, to 50 linear meters per day per work crew. With the improved system of the present application, daily production can average 700 linear meters per day per work gang depending on the conditions of the field and as climate permits. This production increases by more than 10 times. The improved mechanical system of the present invention consists of at least the following devices: 1. A removal device for removing the existing coating materials and the rust including a machine traveling on the pipe, both in the trench, at along the sides of the trench or above the ground. The removal device will remove the coating and / or the rust by any of the following methods: a. rotating chains, b. rotating scraper blade and brushes, c. water jet at high pressure, d. high speed brushes made of wire or other materials, e. sonic and / or vibration cleaning methods; 2. A cleaning device to clean the pipeline that includes a machine that travels over the pipeline and cleans the pipeline as it travels using any of the following materials, sandblasting sand, sandblasting or steel munitions, by using compressed air through nozzles, or other mechanical means of propelling the cleaning materials on the pipe to remove the coating and / or the rust, and preparing the surface of the pipe for the coating; and 3. A coating device for coating the pipe that includes a machine traveling on the pipe and mechanically applying new coating by the following methods: a. mechanical spray system with multiple rolling nozzles which are fixed or revolve around the pipe, b. flood coating consisting of, but not limited to, gravity feed, coating that flows over the pipe, and c. external wrapping placed manually or by an automated machine. The system of the present invention may use a cleaning device for removing coating and / or rust similar to that disclosed in the '748 patent followed by the use of a cleaning apparatus that cleans the pipe as the machine disclosed in the' 016 patent, and then using a coating apparatus similar to that described in the '376 patent for coating the pipe. The novel system of the present invention can use any of the devices listed above to comply with the rehabilitation of existing pipelines, which carry crude oil, refined petroleum products, natural gas or water. Thus, the system of the invention comprises the mechanical processes performed sequentially of: removing old existing coating materials and / or rust, followed immediately by another mechanical process to clean the pipe, and preparing the surface of the pipe to coat or coat it and then replace with a new coating on the existing pipes in the trench, along the sides of the trench or above the ground. The system of the present invention is highly portable for provisional construction / disassembly procedures in the field. In addition, the above devices or units can be used in sequence or in separate stages, that is, # 1, # 2, # 3 in the same section. They do not have to be used all at the same time. The order is important: clean, prepare the surface of the pipe and coat, which is one of the bases of the present invention.
DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of a preferred form of a system for rehabilitating underground pipes incorporating the principles of the present invention.
DESCRIPTION OF THE PREFERRED MODE OF THE INVENTION The preferred embodiment of the present invention will now be described with reference to Fig. 1. Referring now to the drawing for a better understanding of this invention and particularly to Fig. 1, a system 10 for digging and rehabilitating underground or buried pipes includes a removal device 20 to remove existing coating materials and / or rust, which includes a machine traveling on pipe P, either in the trench, along the sides of the ditch or arrives from the earth. The removal device will remove the coating or rust by any of the appropriate methods, such as rotating chains, rotating scraper blades and brushes, high-pressure water jet, high-speed brushes made of wire or other materials, sonic cleaning methods and / or by vibration. After using the removal device 20, a cleaning device 30 is used to clean each tube or pipe, said cleaning device may be in the form of a machine traveling in the pipeline and clean the pipe P in accordance with travel using any of the following sand materials in sand jets, grit or steel munitions, by using compressed air through nozzles, or other mechanical means of propelling the cleaning materials on the pipe to remove the coating and / or the rust; and a coating device 40 for coating the pipe in the form of a machine traveling in pipe P and mechanically applying new coating by any of the following methods: a. mechanical spray system with multiple spray nozzles, which are fixed or revolve around the pipe, b. flood coating consisting of, but not limited to, gravity feed, coating that flows over the pipe, and c. external wrapping placed manually or by an automated machine. The use of the novel system of the present invention will comply with the rehabilitation of existing pipelines, which carry crude oil, refined petroleum products, natural gas or water, where the daily rehabilitation can average 700 linear meters per day per crew or work group depending on the conditions of the field and as the weather permits. This increases production by more than 10 times. This can be achieved with the system of the present invention, which comprises performing in a sequential manner a series of mechanical processes consisting of: removing existing old coating materials and / or rust, followed immediately by another mechanical process of cleaning the pipe, and prepare the surface of the pipe for coating, and then replace with new coating on existing pipes either in the trench, along the sides of the trench or above the ground. Said mechanical processes can be performed separately / or simultaneously by the previous devices. That is, previous devices or units can be used in sequence or in separate stages, that is, # 1, # 2, # 3 in the same section. They do not have to be used all at the same time.