Air abrasive blast line travel machine

Abstract: A pipeline treating apparatus (10) is disclosed which is used to clean the exterior of a pipeline (12) with high pressure air with entrained abrasive. The apparatus has an improved classifier and separator to separate the abrasive grit from lighter debris which includes a classifier and separator within a manifold duct which returns the grit to a collection pan for recovery and causes the lighter airborne dust to be removed through a return duct. A series of pressure relief filters reduce the air pressure within a blast chamber (18) and resist debris escaping from the blast chamber past the triple seals. The blast nozzle assemblies are attached to the nozzle oscillating frames by snap fittings which avoids threaded connections which may become contaminated by the debris.

Description: TECHNICAL FIELD OF THE INVENTION This invention relates to a machine for traveling along a pipe or pipeline to clean the surface with an abrasive. BACKGROUND OF THE INVENTION A pipeline is typically coated with a protective coating, such a protective tape or other material. After a period of time underground, this coating will deteriorate, requiring the pipeline to be dug up, the old coating removed and a new coating applied in order to maximize the life of the pipeline. The cleaning of an older coating on a pipeline should be accomplished as rapidly as possible, as inexpensively as possible, and with minimum damage to the pipeline itself. There is a growing need for this service as many pipelines have now been underground sufficiently long that they do need to be treated. Further, improved coatings are being developed which make it desirable to remove the lesser effective original coatings and replace them with the new coatings. A need therefore exists for a machine and process which cleans a pipeline quickly and effectively. WO 92/12826 discloses a pipeline treating apparatus comprising the features of the preamble of Claim 1. The apparatus has two housing sections which are pivotally mounted on a mainframe and which, when closed around a pipeline, define a chamber around the pipeline. Nozzles are mounted on the housing sections to discharge treating media against the surface of the pipeline. The nozzles are directly mounted on the housing sections in a pivotal manner and connected to a driving mechanism which causes an oscillating pivoting movement of the discharge nozzles. Abrasive particles and matter removed from the pipeline surface are returned from an opening in the housing through a return line to a cleaner for removal of the foreign matter and return of the abrasive particles for recycling. EP 0 578 343 shows a pipeline treating apparatus which will be described in detail in connection with Figures 1 to 16 below. In this apparatus nozzles are mounted on carriages which are guided for arcuate movement within the housing sections and driven to oscillate forth and back. Abrasive particles and debris removed from the exterior of the pipeline fall by gravity near the bottom of the apparatus. Manifolds are provided at the bottom of the apparatus and are connected to vacuum piping to draw the debris and material out for separation, treatment and disposal. US-A-5 134 810 discloses a pipeline treating apparatus. The apparatus includes a simple housing which carries a plurality of blast wheels specificially positioned to provide a frustoconical curtain of abrasive particles through which the pipe being cleaned passes. Spent abrasive particles and removed material are collected at the bottom of the cleaning machine in a collection trough. The abrasive particles and removed material are collected and discharged in a curtain through which air flows so as to separate the foreign matter from the abrasive particles. The abrasive particles then fall into hoppers from which they are delivered to the individual blast wheels. WO 91/11293 discloses a pipeline treating apparatus. The housing surrounding the pipeline consists of three housing sections of equal dimensions, two of them being pivotally mounted on the third so that the first two can be opened to be pivoted away from the pipeline. Each of the three housing section carries nozzles which are pivotally mounted thereon for pivoting around an axis parallel to the longitudinal axis of the pipeline. The nozzles are driven to an oscillating movement in the housing sections. The discharged abrasive particles are removed from the bottom of the housing and returned to a trailor or skid pulled alongside the apparatus for cleaning and storage for another cycle. According to the present invention a pipeline treating apparatus according to the preamble of Claim 1 is characterized in that a first nozzle frame is pivotally mounted to the mainframe separately from the first housing section and extending about substantially one-half the circumference of the pipeline, a second nozzle frame is pivotally mounted on the mainframe separately from the second housing section extending about substantially the other half of the circumference of the pipeline, a first nozzle plate is mounted on the first nozzle frame for oscillating motion relative thereto, a second nozzle plate is mounted on the second nozzle frame for oscillating motion relative thereto, at least one nozzle is mounted on each of the nozzle plates for discharging a treating media against the surface of the pipeline, and at least one duct is connecting each of the housing sections with the classifier and separator unit to move debris and treating media from the chamber to the classifier and separator unit. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be better understood upon reading the detailed description set forth below in connection with the following drawings. Figs. 1-16 show a pipeline treating apparatus of the prior art as disclosed in EP 0 578 343 A1. In the drawings: FIGURE 1 is a side view of an automated pipeline treating apparatus of the prior art as disclosed in EP 0 578 343 A1; FIGURE 2 is a side view of the automated jet cleaning unit used in the apparatus of FIGURE 1; FIGURE 3 is a front view of the automated jet cleaning unit of FIGURE 2; FIGURE 4 is a top view of the automated jet cleaning unit of FIGURE 2; FIGURE 5 is an end view of the nozzle carriage assembly and abrasive cleaning nozzles utilized in the apparatus of Fig. 1; FIGURE 6 is an end view of the nozzle carriage assembly and abrasive cleaning nozzles with the arcuate rings on which the nozzles are mounted pivoted to the removal position; FIGURE 7 is an end view of the centering assembly used in the apparatus centered about a pipeline; FIGURE 8 is an end view of the centering apparatus in the removal position; FIGURE 9 is a schematic view of the chain drive for the abrasive cleaning nozzles in the operating orientation; FIGURE 10 is an illustrative view of the chain drive in the removal position; FIGURE 11 is an end view of the nozzle carriage assembly and abrasive cleaning nozzles illustrating the chain drive; FIGURE 12 is a side view of the nozzle carriage assembly and abrasive cleaning nozzles; FIGURE 13 is an illustrative view of the arcuate rings and abrasive cleaning nozzles in the operating position; FIGURE 14 is an illustrative view of the arcuate rings pivoted to the removal position. FIGURE 15 is an illustrative view of the nozzle used in the apparatus; FIGURE 16 is an illustrative view of the travel path of the spray from the nozzle; FIGURE 17 is an exploded perspective view of a carriage forming a first embodiment of the present invention; FIGURE 18 is a detail view of the collection pan used in the carriage; FIGURE 19 is a detail cross-sectional view of a port in the collection pan; FIGURE 20 is an end view in partial cross-section of the carriage; FIGURE 21 is a side view in partial cross-section of the carriage; FIGURE 22 is an end view of the first housing section of the carriage, FIGURE 23 is an end view of the first nozzle frame of the carriage; FIGURE 24 is an end view of the first nozzle plate of the carriage; FIGURE 25 is a side view in partial cross-section of the first oscillation drive of the carriage; FIGURE 26 is a top view in partial cross-section of the first oscillation drive of the carriage; FIGURE 27 is a partial cross-sectional view of the carriage showing the nozzle plate; FIGURE 28 is a top view and partial cross-section of the main frame of the carriage; FIGURE 29 is an end view, in partial cross-section, of the carriage with the housing sections and the nozzle frames moved to the removal position; FIGURE 30 is a detail view of the guide rollers of the carriage; FIGURE 31 is a side view of an eighth embodiment of the present invention; FIGURE 32 is an end view of the embodiment of FIGURE 31; FIGURE 33 is an end view from the opposite end of the embodiment shown in FIGURE 31; FIGURE 34 is a top view of the embodiment of FIGURE 31; FIGURE 35 is a plan view of the nozzle assembly; FIGURE 36 is a side view of the nozzle assembly; FIGURE 37 is a side view of an elbow for the nozzle; FIGURE 38 is a side view of a modified elbow for the nozzle; FIGURE 39 is an end view showing the flexible shield; and FIGURE 40 is a side view of the apparatus. DETAILED DESCRIPTION With reference now to the accompanying drawings, wherein like reference numerals designate like or similar parts throughout the several views, an automated pipeline treating apparatus 10 of the prior art as disclosed in EP-A-0 578 343 is illustrated in FIGURES 1-16 in order to describe the technical background of the invention. . The apparatus 10 is used to clean and/or coat a pipeline 12, which can be either a new pipeline or a previously coated pipeline in need of rehabilitation. Typically, the pipeline to be rehabilitated will be a pipeline which has just been uncovered and raised out of the ditch with the original coating on the pipeline having degraded to a condition that is no longer serviceable. In various modes of the apparatus 10, the apparatus can be used to clean any old coating off the pipeline and condition the outer surface of the pipeline itself for a new coating. In another mode, the apparatus 10 can be used to spray on the new coating once the pipeline surface has been prepared. In the cleaning and surface preparation mode, the apparatus 10 includes three major sections, a sled unit 14, a travel unit 16 and an automated jet cleaning unit 18. The sled unit 14 is commonly mounted on tracks which is pulled parallel to the pipeline being treated and the weight of the sled unit thus has no effect whatsoever on the pipeline. In contrast, the travel unit 16 and automated jet cleaning unit 18 are supported on the pipeline itself for movement along the axis 20 of the pipe in the direction of arrow 22. The weight of the travel unit and automated jet cleaning unit will be such as to be readily carried by the pipeline without damage. The weight of these units does not have to be supported by a side boom or other lifting device during operation. With reference to FIGURES 2-8, various details of the automated jet cleaning unit 18 can be further described. The unit 18 includes a centering assembly 24. As best shown in FIGURES 7 and 8, the centering assembly 24 can be seen to include pivotal arms 26 and 28 which pivot on frame member 30 through the action of air cylinders 32 between an operating position, shown in FIGURE 7, and an installation or removal position, shown in FIGURE 8. Each of the arms, and the frame member mount an aligned pair of guide wheels 34 to support the centering assembly 24 on the pipeline. In the operating position, as seen in FIGURE 7, the three pairs of guide wheels are distributed at 120° from each other around the pipeline so that the centering assembly 24 is centered on the pipeline. preferably, air pressure is maintained in cylinders 32 when the centering assembly is in the operating position to hold wheels 34 firmly against the pipeline to keep the centering assembly centered on the axis 20 of the pipe despite weld joints and surface irregularities. Attached to the centering assembly 24 is a nozzle carriage assembly 36. The nozzle carriage assembly 36 includes two arcuate rings 38 and 40. Ring 38 is rigidly secured to arm 26. Ring 40 is similarly rigidly secured to arm 28. Thus, as seen in FIGURE 6, as the cylinders 32 operate to pivot arms 26 and 28 into the installation or removal position, the arcuate rings 38 and 40 are similarly deployed. As best seen in FIGURE 4, the rings 38 and 40 are spaced apart a distance L from each other along the pipeline axis 20. The rings preferably have an arc greater than 180°. The radius of the rings 38 and 40 is selected so that the rings are concentric with the pipeline axis 20 when the arms 26 and 28 are in the operating position. Thus, in the operating position, the rings 38 and 40 are at a constant distance from the outer surface of the pipeline about the entire circumference of the pipeline. Mounted on the arcuate rings 38 and 40 are a series of abrasive cleaning nozzle carriages 42, with each carriage supporting an abrasive cleaning nozzle 44. There are illustrated six carriages and nozzles on each of the rings 38 and 40. However, this number can be varied as will be described in detail hereinafter. Each of the carriages 42 is supported on a ring by a series of wheels 46 guided on the inner and outer edges of the ring to permit the carriage and attached nozzle to move in an arcuate manner along the ring. Each of the carriages on a particular ring are interconnected by links 48 pivoted between adjacent carriages. Thus, motion of a carriage will be mirrored by the motion of the rest of the carriages on that particular ring. With reference to FIGURE 15, the details of the abrasive cleaning nozzles 44 can be described. The nozzles have passages 50 to carry high pressure water, for example in a pressure range of 690 - 1035 bar (10,000 - 15,000 psi). An abrasive channel 52 carries abrasives (typically sand) which are entrained in the water flow to enhance the cleaning activity of the nozzle. As can be seen, the high pressure water is sprayed from the nozzle through ports 54 at an angle relative to the center axis 56 of the nozzle and toward the axis 56. This creates a relative vacuum at passage 52 to entrain the abrasives in the water jet flow to enhance the cleaning action and provide an additional force to move the abrasive. As can be seen in FIGURE 2, the abrasive nozzles 44 are preferably mounted on their carriages so that the jet impinges on the outer surface of the pipeline at an oblique angle to the surface. The nozzles are preferably adjustably mounted to allow the operator to select the best angle. It has been found that this enhances the efficiency of cleaning. The use of high pressure water jets, particularly with entrained abrasives, is an improvement over shot blast cleaning, where shot impinges against the outer surface of the pipeline. Shot blast cleaning leaves a relatively smooth outer surface to the pipeline, which is not a suitable surface profile for bonding with adhesive to apply a new coat on the pipeline. The high pressure water jet, particularly with entrained abrasives, generates a highly irregular angular surface which is very conducive for bonding with adhesive. With reference to FIGURES 9-12, the mechanism for oscillating the nozzles 44 will be described. Mounted atop the centering assembly 24 is a control module 58. Within the control module is a motor 60 with a drive shaft 62 which extends out of the module and through the assembly 36 and extends parallel to the axis 20 of the pipeline when the units are in the operating position. The motor rotates shaft 62 in the direction of the arrow with an adjustable predetermined angular velocity. A first drive gear 64 is mounted on the shaft adjacent the ring 38. A second drive gear 66 is mounted on the shaft adjacent the arcuate ring 40. As seen in FIGURES 10 and 11, the first drive gear drives a first driven gear 68 through a chain 70. The second drive gear drives a second driven gear 72 through a chain 74. Drive gears 68 and 72 are supported from frame member 30 so that the distance between the gears does not vary whether the arms are in the operating or installation and removal position. Arcuate ring 38 supports a continuous chain 76 which is supported about the periphery of the ring for 30° of the entire length of the ring. Arcuate ring 40 mounts a continuous chain 78 in the same manner. First driven gear 68 drives a gear 80 which engages the chain 76 when the device is in the operating position as shown in FIGURE 9. Second driven gear 72 similarly drives a gear 82 which is engaged with chain 78 in the operating position. When cylinders 32 are actuated to pivot arms 26 and 28 into the installation/removal position, the chains 76 and 78 simply move out of engagement with the gears 80 and 82, as best seen in FIGURE 10, to disconnect the drive train. Similarly, when the arms are pivoted to the operating position, the chains 76 and 78 re-engage the gears 80 and 82, respectively, to complete the drive train. In operation, the travel unit 16 will drive the cleaning unit 18 along the pipeline, while the motor 60 oscillates the nozzles 44. Chains 76 and 78 each have a special link in them which receives a floating pin extending from the nozzle carriage 42' closest to the drive motor. The continuous rotation of chains 76 and 78 translate into oscillation of nozzle carriage 42' about an arcuate distance on rings 38 and 40 determined by the length of the chains 76 and 78. The pin floats a limited direction on a radial line perpendicular to axis 22 when the arms and rings are in the operation position to follow the special link in its travel. If only a single nozzle carriage and nozzle were used on each ring, chains 76 and 78 need only be lengthened to extend about a 180° arc of the periphery of the rings, as shown in FIGURES 9 and 10. As best seen in FIGURE 16, the width W that each nozzle travels should be twice the distance D that the nozzles moves along the pipeline. Further, the arc of reciprocation for the nozzles should be about 360° divided by the number of nozzles to ensure complete coverage of the outer surface of the pipeline. For example, if twelve nozzles are used, six on each of the rings, the arc of reciprocation should be 30°. By following this standard, every area on the pipeline will be covered twice by nozzles as the apparatus moves along the pipeline to ensure cleaning of the pipeline. With such operation, a surface finish of ISO SA 2-1/2 should be possible with a highly angular surface profile of up to 0.003 inches in mean differential to provide a superior base for a new coating. The centering assembly 24 positions the nozzle carriage assembly 36 on the pipeline and ensures that the nozzles 44 maintain the proper standoff from the pipeline. The control module 58 directs the flow of water and abrasive to the individual nozzles and controls the oscillation of the nozzles. A two part cover 84 is mounted on the arms 26 and 28 to overly the nozzles to protect the operator and other personnel from ricocheting water and abrasive spray. The high speed water jets in the nozzles accelerate the individual abrasive particles, typically sand, to greatly increase the momentum of the particle and allow it to more efficiently remove contaminants on the pipeline surface and obtain the needed surface profile. The high speed water jet attacks the interface that bonds the coating or contaminant to the pipe itself and removes all loosely bonded material. In addition, the water will dissolve and remove any corrosion causing salts on the pipeline. The erosive action of the abrasive is used to remove the tightly bonded material such as rust and primer and provide the desired surface profile for receiving a new coating. The sled unit 14 is designed to be towed as a separate vehicle behind the travel unit 16 and cleaning unit 18 as they move along the pipeline. The sled unit mounts the control panel for the various functions of the apparatus, and includes a computer to maintain the desired relation between speed of the units along the pipeline and the speed of oscillation of the nozzles. The sled unit also contains high pressure pump units used to provide the high pressure water at nozzles 44. One, two or three pumps can be run in tandem depending on the size of the pipeline to be cleaned and the degree of cleaning desired. Using less than the total number of pumps minimizes water consumption, fuel costs and maintenance when the full capacity is not required. Also, in the event one of the pump units goes off line, another unit can be brought on line quickly to replace it. A quintuplex positive displacement pump with stainless steel fluid and pressure lubricated power ends is a satisfactory pump. Such a pump can be rated at 10,000 psi at 34.3 gallons per minute, for example. The sled unit also contains a compressor to operate the cylinders 32, a generator for electrical power for the motor 60 and to power the air compressor and other controls. Also, the sled unit mounts containers of the abrasive to feed the cleaning unit 18. The chain drive and single direction rotating motor that oscillate the nozzles provide a smooth ramp up and ramp down of the nozzle operation at the ends of the nozzle path, not possible if a reversing motor is used to oscillate the nozzles. The nozzles slow up smoothly as they reach the end of their oscillation arc and accelerate smoothly as they reverse their motion. This provides a smooth operation. As noted, for twelve nozzles, the arc of reciprocation should be 30°. For ten nozzles, the arc should be about 36°. For eight nozzles, the arc should be about 45°. The apparatus 10 can be used to apply a new coating to the pipeline as well. Instead of nozzles 44 to apply abrasives and high pressure water jets, the nozzles 44 can be used to spray a polyurethane coating on to the pipeline. A polyurethane coating of the type that can be used for such coating is sold under the trademark and identification PROTOGOL UT 32 10 and is manufactured by T.I.B.-Chemie, a company located in Mannheim, West Germany. This polyurethane material is a two part material, one part being a resin and the other an isocyanate. When the two parts are mixed in a 4 to 1 ratio of resin to isocyanate, the material sets up in a hard state within thirty seconds of mixing. The apparatus 10 thus is an ideal device to apply such a spray in a continuous manner along the pipeline, providing, with the nozzle overlap, complete coating of the pipeline to the desired coating thickness as the apparatus moves along the pipeline. After the polyurethane has been applied, solvent will be driven through the nozzles and supply passages to prevent the polyurethane from hardening and ruining the apparatus. It is also possible to use only one oscillating nozzle per ring to apply the coating by oscillating each nozzle 180° or so and moving the unit along the pipeline to insure complete coverage. It is also possible to mount a plurality of nozzles in a fixed position on rings 38 and 40 for either cleaning or coating if oscillation is not desired. To insure consistent cleaning, surface preparation and even coverage of the coating material being applied, it is desirable if the spray nozzle position can be adjusted. The spray nozzles may vary in the width of the spray pattern, profile of the pattern, and size of the orifice. These variations are a result of the manufacturing tolerances encountered in the manufacturing of the spray nozzle. Variations will also occur as the spray nozzle wears during operation. The amount of material (water, water and abrasive, and/or coating) directed or applied to the surface of the pipe per unit of time is affected by the variables listed above. The spray exits the spray nozzle in a "fan" pattern. The closer a spray nozzle is to the surface of the pipeline, the smaller the "footprint" made by the spray on the pipeline. As the width of the spray pattern at a specified distance from the spray nozzle may vary, the desired spray "footprint" on the pipeline can be obtained if the distance of the spray nozzle from the pipeline can be adjusted. During the operation of the spray nozzles, the nozzles become worn and the fan pattern width at a given distance will decrease. To compensate for this wear and to prolong the useful life of the spray nozzle, it is necessary to increase the distance of the spray nozzle from the pipeline. This should be done frequently to insure optimum performance. The profile of the spray pattern may vary also. This can result in the pattern being skewed to one side or the other. Skewing of the fan pattern can cause a portion of the fan pattern to miss the desired target on the pipeline. This skewing can be severe enough that a portion of the spray pattern may actually miss the pipeline entirely, causing inefficiencies and loss of water, water and abrasive, or coating material. To compensate for this, the spray nozzle needs to be moved arcuately, along the arcuate ring. The size of the orifice can vary from spray nozzle to spray nozzle. The larger the orifice, the greater amount of material that will exit the nozzle per unit of time. The sprayed material exits the nozzle in a "fan" pattern, consequently the amount of spray material contacting the pipeline per square inch per unit of time can be decreased by increasing the distance of the spray nozzle from the pipeline. To compensate for these numerous factors it is desirable to be able to adjust the distance of the spray nozzle from the pipeline and the position of the spray nozzle around the arcuate ring. Further, these adjustments must be made while the unit is operating so the adjusting mechanism must be capable of being operated by worker in bulky protective clothing and heavy gloves. The adjustments, once made, should be able to get "locked" in to prevent the spray nozzle position from changing due to vibration or operation of the equipment. When spraying water, water and abrasive, or coating materials, the orifice of the spray nozzle will occasionally become partially of completely plugged with foreign matter. This will distort the spray pattern if partial blockage occurs and reduce the amount of material per unit of time being sprayed through the nozzle. This problem is particularly significant when rapid set coating materials are used. If spray nozzle blockage occurs in this situation and flow cannot be restarted quickly, the coating material in the system will set up and require stopping work and rebuilding the entire system. Many times this blockage can be removed from the spray nozzle if the spray nozzle can be rotated 180° and the blockage "blown out" of the spray nozzle using the high pressure water, water and abrasive or coating. The nozzle can then be rotated back to the operating position and commence spraying. With reference now to FIGURES 17 - 29, an embodiment of the invention is illustrated and identified as apparatus 600. The apparatus 600 can be used to clean, blast or coat the pipeline. The apparatus 600 has a main frame 602 which is supported through rollers on the pipe being treated. Supported from the main frame 602 are a first housing section 604 and a second housing section 606. The housing sections are pivoted to the main frame for pivotal motion from an operational position, where the housing sections fit closely about the outer circumference of the pipe to define a chamber 608 therein (FIGURE 21), to a removal position where the housing sections 604 and 606 are separated from each other to permit the apparatus 600 to be lifted off or lowered onto the pipe (FIGURE 29). A first nozzle frame 610 and a second nozzle frame 612 are pivoted to the main frame 602 and similarly can move, independent of housing section 604 and 606, between an operational position concentric with the pipe being treated and a removal position permitting the apparatus 600 to be lifted on or lowered onto the pipe (FIGURES 20, 29). The first nozzle frame 610 mounts a first nozzle plate 614 and a first oscillation drive 616 which oscillates the nozzle plate 614 relative to the nozzle frame 610 and to the circumference of the pipe. A second nozzle plate 618 and a second oscillation drive 620 are mounted to the second nozzle frame 612 for similar oscillation motion. The individual nozzles 622 are mounted on the nozzle plates 614 and 618 and are oscillated through a predetermined arc relative to the outer circumference of the pipe to perform the desired operation. With reference to FIGURE 28, the main frame 602 can be seen to include unpowered rollers 624 and 626 at one end of the frame and powered rollers 628 and 630 at the other end of the frame. The rollers support the apparatus 600 on the pipe and drive the apparatus 600 along the pipe during treatment. The powered rollers are driven by a motor 632 acting through a gear reduction unit 634 and a chain drive which rotates the rollers 628 and 630. With reference to FIGURES 21 and 22, the first housing section 604 will be described. The second housing section 606 is essentially identical, being a mirror image of the first housing section 604. The first housing section 604 defines a hemicylindrical member including a hemicylindrical outer plate 636 and side plates 638 and 640 which combine to define the chamber 608. Extending outwardly from each side plate is a hemicylindrical side outer plate 642 and, from the outer edge of plate 642, an outer side plate 644. The plates 638, 640 and 644 and side outer plate 642 define outer chambers 646. A pair of seals 648 and 650 are mounted on either side of plates 638 and 640 to isolate the chamber 608 from the outer chamber 646. Similar seals 652 and 654 are mounted on opposite sides of each of the outer side plates 644 to prevent material from escaping from the outer chambers exterior the apparatus. Thus, for material to escape to the exterior of the apparatus, it must first pass the double seals between the chamber 608 and the outer chambers 646 and then pass the double seals between the outer chambers 646 and the exterior of the apparatus. Most of the debris in chamber 608, and the debris which forces its way into outer chambers 646 simply will fall by gravity to the bottom of the apparatus where it will be collected in a collection pan as described hereinafter. With reference to FIGURE 22, the first housing section 604 can be seen to be pivoted to the main frame 602 through a pair of brackets 656 hinged on hinge pins 658 on the main frame 602. A dust collection duct 660 is mounted on each housing section over an aperture in the outer plate 636 near the top of the housing section for collection of airborne dust and the like. A deflector section 661 in the duct will reduce the kinetic energy of any debris thrown outward in the duct from chamber 608. The duct may be connected to a vacuum source to draw the dust from chamber 608 for disposal. As seen in FIGURE 21, a gap 662 is formed in each of the outer plates 636 which permits the discharge of each of the nozzles 622 to enter the chamber 608. The gap is preferably in two sections, broken by a bridge at about the middle of the housing section. The first housing section also mounts guide wheels 664 on each of the outer side plates 644 to contact the outer surface of the pipe to assist in centering the housing sections about the pipe axis. The first housing section 604 is moved between the operational position and the removal position by a pair of cylinders 666 mounted on the main frame with the piston 668 of each cylinder pivoted to the first housing section. The cylinders 666 hold the housing section in the operational position as well as the removal position. With reference to FIGURE 21 and 23, the first nozzle frame 610 will be described. The second nozzle frame 612 is substantially identical, being a mirror image of the first nozzle frame 610. The first nozzle frame is formed of a left half 670 and a right half 672. Each half includes an arcuate beam 674 which extends about 180°. A bracket 676 is mounted at the top of each beam for pivotal mounting on the main frame 602 through holes 701 by pivot pins. A pin 678 is received through holes 705 of brackets 676 and holes 707 in oscillation drive 616. A guide wheel 680 is mounted on the beam 674 to engage the outer surface of the pipe to assist in insuring the first nozzle frame is concentric with the pipe axis. A bracket 682 is mounted on the beam 674 and pivotally mounts the end of a piston 684 of a cylinder 686 to move the nozzle frame from the operation position concentric with the pipeline to the removal position. The cylinders 686 hold the nozzle frame in the operational position as well as the removal position. On the inside surface of the arcuate beam 674 is mounted a cylindrical guide tube 688 which extends about 150° of arc. As will be described hereinafter, the first nozzle plate 614 is guided for oscillating motion along the guide tubes 688 and also acts to maintain the two halves 670 and 672 of the nozzle frame at the same distance from the pipe being treated. Two halves 670 and 672 are also connected by a cross brace 689 which does not interfere with the oscillation of the nozzle plate. With reference now to FIGURES 67 and 70, the first nozzle plate 614 will be described. The second nozzle plate 618 is substantially identical, being a mirror image of the first nozzle plate 614. The first nozzle plate 614 defines an outer cylindrical plate 690 which extends for an arc less than 180°, preferably about 140°. Side plates 692 and 694 extend radially inward from the inner surface of the plate 690 spaced inwardly of the outer edges of the plate 690. On each side plate is mounted three roller carriages 696 which engage the guide tubes 688 of the first nozzle frame 610, permitting the first nozzle plate to move in an arcuate direction relative to the first nozzle frame along the guide tubes. Four guide wheels 698 are mounted on the outer cylindrical plate 690 and bear against the outer surface of 604 (Fig. 17) binding of the roller carriages 696 and guide tubes 688 and to properly space the halves of the first nozzle frame. Near the top of the plate 690 is mounted a bracket 700. Multiple nozzles 622 are mounted on the outer cylindrical plate 690 and extend therethrough at equal spaced arcs along the plate. For example, four nozzles can be mounted on the plate at 45° spacing as shown, or five nozzles at 36° spacing, or any other number of nozzles desired. With reference to FIGURES 25 and 26, the first oscillation drive 616 will be described. The second oscillation drive 620 is substantially identical. The first oscillation drive 616 includes a casing 702 forming a frame which is pivoted to the main frame 602 at holes 703 and attached to the first nozzle frame 610 at holes 707 by pin 678 spaced from the axis of holes 703 which allows the first oscillation drive 616 to pivot with the first nozzle frame 610 and the first nozzle plate 614. A motor 704 is mounted on the frame which drives a gear reduction unit 706 to rotate an output shaft 708. A pair of gears 710 are mounted on the shaft 708 for rotation therewith. A pair of intermediate gears 712 are mounted on the frame spaced from gear 710. Chains 714 interconnect aligned gears 710 and 712 for joint rotation. Gears 722 are mounted in casing 702 and are driven by gears 712 though chains 724. A drive link 716 is mounted between the chains 724 so that as the gears rotate, the drive link 716 is moved in a circular pattern first around gears 712 and then around gears 722. A drive bracket 718 is bolted to the bracket 700 on the first nozzle plate. A slot 720 is formed in the drive bracket which receives the drive link 716. Thus, as the motor is continuously rotated in a single direction, the gears will cause the drive link 716 to move in a continuous elongated circular pattern which, in turn, causes the drive bracket 718 to move in an oscillating arcuate manner to oscillate the first nozzle plate 614 and the nozzles mounted thereon. The use of the chain drive allows the nozzles 622 to dwell longer at the end of its arc of travel to give better treatment at the limits of nozzle motion. This occurs because the linear speed of the chain is constant and the nozzle oscillation will slow down and dwell at the limits of its motion as the drive link 716 follows the chains about the circumference of the gears 712 and 722. By changing the diameter of gears 712 and 722 this dwell time can be varied. Even with this advantage of dwell time, the nozzle motion is smooth, without sudden stops or starts because the linear speed of the chain remains uniform throughout the oscillation. With reference to FIGURES 18, 20 and 21, a collection pan assembly 726 is mounted between the first and second nozzle frames 610 and 612 and is designed to catch the debris discharged from the chamber 608 and from the outer chambers 646 for collection and disposal. The housing sections 604 and 606 have holes or apertures at their lower ends which lie above the collection pan assembly 726. The debris from chambers 608 and 646 fall through these holes or apertures into the collection pan assembly. The assembly includes a collection pan 728 which has guide rails 730 and 732 mounted on opposite sides thereof. The rails 730 and 732 define a C-shaped cross section and each receive guide rollers 734 and 736 mounted on the first and second nozzle frames 610 and 612, respectively. As the nozzle frames are pivoted to the operational position, the guide rollers 734 and 736 run along the guide rails 730 and 732 to lift the collection pan 728 closer to the bottom of the housing section 604 and 606. When the nozzle frames are moved to the removal position, the guide rollers 734 and 736 move outwardly on the guide rails 730 and 732, permitting the collection pan 728 to drop downward relative to the bottom of the housing sections 604 and 606. As best seen in FIGURE 30, each of the guide rollers 734 and 736 is mounted to its respective nozzle frame by two quick release pins 738 allowing the collection pan assembly to be quickly removed from the nozzle frames and permitting the apparatus 600 to be removed from or placed onto the pipe. Only one of the quick release pins need be removed, permitting the guide rollers to be pivoted outwardly about the other quick release pin as shown in phantom in FIGURE 30. On one side of the collection pan 728 ports 740 are formed through the side and mount discharge conduits 742 for drawing the debris from the collection pan 728 to a remote location for disposal. In any of apparatus 350, 500, 550 and 600, each of the wings, housing sections and nozzle sections can be formed in multiple pivoting portions to facilitate installation and removal of the apparatus from the pipeline. With reference now to FIGURE 31, a pipeline treating apparatus 810 is illustrated forming an eighth embodiment of the present invention. In all respects except as noted hereafter, apparatus 810 is essentially identical to apparatus 600. The apparatus 810 is designed to travel along a pipe or pipeline 812 to clean the pipeline with jets of high pressure air with abrasive entrained in the air flow. The apparatus 810 includes a frame 814 which mounts front rollers 816 and rear rollers 818 which engage the upper surface of the pipeline to support the weight of the apparatus directly on the pipeline. The frame 814 includes a lifting eye 820 which permits the apparatus to be removed from or installed on the pipeline by a crane or the like. Frame 814 also mounts a main drive 822 which rotates the front rollers 816 to drive the apparatus 810 along the pipeline as the pipeline is cleaned. A first blast chamber housing 824 and a second blast chamber housing 826 are pivoted from the frame 814 and completely surround the exterior of the pipeline along a portion of its length to define a blast chamber 828. The housings 824 and 826 can be pivoted from the cleaning position surrounding the pipe, as seen in FIGURES 77, 78 and 79, to a position pivoted away from the pipeline to allow the apparatus to be removed and installed from the pipeline. The blast chamber housings are very similar to housing sections 604 and 606 in apparatus 600. A first nozzle oscillating frame 830 and second nozzle oscillating frame 832 are also pivoted onto the frame 814 separate from the housings 824 and 826. Frames 830 and 832 are very similar to nozzle frames 610 and 612 in apparatus 600. Each of the frames 830 and 832 mount a series of nozzle assemblies 834 with nozzles 911 on an oscillating plate 836 for delivery of the high pressure air and entrained abrasives to the exterior of the pipeline. The plates 836 are oscillated a predetermined arc about the exterior circumference of the pipeline by drives 838 mounted on the frames. The nozzles pass through a slit opening in the housings so that the nozzles discharge directly against the exterior of the pipeline surface. As the high pressure air and abrasive remove the old coating from the pipeline, a large quantity of debris is generated, which includes the old coating removed from the pipeline and the abrasive. This debris must be removed from the apparatus to maintain the efficiency of the apparatus. Further, it is desirable to separate the components of the old coating from the abrasive to allow the abrasive to be reused. In the present invention, heavier and larger debris will fall to the bottom of the blast chamber 828 and into a collection pan 840. Pan 840 is very similar to pan assembly 726 of apparatus 600. Vacuum ducts 842 extend from the pan and are connected to a source of vacuum to draw the debris from the pan for sorting in a device traveling alongside the apparatus 810 on the right-of-way. The debris pan is preferably formed of aluminum to save weight. Apparatus 810 further has a series of four vacuum ducts or hoses 844, 846, 848 and 850 connected about the mid-portion of each housing 824 and 826 near both ends of the housings. The ducts are preferably four inches in diameter. Ducts 844 and 846 extend to a header duct 852 on one side of the apparatus while ducts 848 and 850 extend to another header duct 854 on the opposite side of the apparatus. The ducts 852 and 854 are preferably eight inches in diameter. The rearward ends of the header ducts 852 and 854 are, in turn, connected to a manifold duct 856. A single centrally oriented return duct 858 is mounted on the manifold and is connected to a source of vacuum (not shown). Duct 858 is preferably twelve inches in diameter. The vacuum drawn through the ducts causes airborne debris and dust within the blast chamber to be sucked along the ducts. The tortuous chamber defined by interior panels within the manifold duct 856 assist in separating the lighter airborne debris from the material removed from the pipeline from the heavier abrasive media. The length of ducts 844-854 and the tortuous chamber allows the abrasive to lose its momentum. The heavier material falls into hoppers 866 and 868 formed as part of the manifold duct 856 and then falls into collection pan 840. The dust will be drawn through the return duct 858 for disposal. Each of the oscillating frames supports five nozzle assemblies 834. Therefore, the nozzle assemblies will have to be oscillated in an arc of about 36° in order to cover the entire exterior of the pipeline. Each nozzle assembly is supplied with abrasive and high pressure air through a hose 870 attached thereto. A hose support frame 872 is mounted at the rear of frame 814 which supports each of the hoses in a position approximate the center its associated nozzle's oscillation. Each of the nozzle assemblies is mounted on the oscillating frames by a snap fit fitting 834 shown in detail in FIGURES 35 - 40. The fitting 834 includes a U-shaped bracket 900 which is bolted to one of the oscillating plates 836. The facing sides of the bracket have a pair of aligned attachment holes 902 and safety holes 904. A nozzle block 906 is inserted within the U-shaped bracket 900 and secured thereto by a pair of quick fastening pins 908 which pass through the attachment holes 902. The nozzle 911 itself is attached to an elbow 910 which has a flange 912. FIGURES 35, 36, and 38 illustrate a right angle elbow 910. FIGURE 37 shows a 45° elbow 910. The nozzle block 906 has an aperture 914 to receive the nozzle and a portion of the elbow so that the flange 912 is positioned slightly above the upper surface 916 of the block 906. A pair of securing clamps 918 are bolted to the block 906 on either side of the nozzle with bolts 920. Each securing clamp has a actuate bearing ring 922 which engages the flange 912 to secure the elbow 910, and thus the nozzle, to the nozzle block 906. Thus, to remove the nozzle, only four bolts 920 need be removed to remove the securing clamps 918 from the nozzle block 906 and the elbow 910 can simple be lifted out of the nozzle block 906. This permits the nozzles to be readily installed and removed. A threaded connection tends to become filled with debris, which made it difficult to change nozzles. Another advantage of this design is the possibility of using nozzles 911 of different configuration to tailor the nozzle to a particular application. For example, the stand off, or distance from the end of the nozzle 911 to the pipe surface being treated may need to be varied for a particular application. By installing nozzles of different length, or possibly a nozzle with an expansion adaptor on it, the machine can be tailored for the specific application relatively easily. Also, the use of securing clamps 918 allow the nozzle to be pivoted about along its axis by simply loosening the securing clamps 918 sufficient to permit the pivotal motion. This permits less strain to be exerted on the hose connecting the nozzle to the pressure source as the nozzle can be pivoted to conform with the position of the hose. The blast chamber housings 824 and 826 are sealed at their ends to the outer surface of the pipeline to prevent debris from escaping exterior of the blast chamber. As best seen in FIGURE 31, triple seals at each end are employed, which include annular seal 876, annular seal 878 and annular seal 880. Annular seal 880 is a double seal as seen in FIGURE 31. Between the inner annular seal 876 and the intermediate annular seal 878, a passage is provided for debris to fall into the collection pan 840. By having a triple seal, the amount of debris escaping from the blast chamber will be better controlled. In addition to the use of triple seals, pressure relief filters 882 (FIGURE 33) are mounted on the front ends and rear ends of the blast chamber housings which reduces the air pressure within the blast chamber 828 to reduce the driving force that would tend to drive debris past the seals 876 - 880. Preferably, two filters 882 are mounted at each end of each housing, for a total of eight. The filters permit air to escape from the blast chamber to reduce the air pressure therein but filter out the debris so that the debris stays within the blast chamber. It would be expected that the filters would need to be cleaned or replaced at fairly frequent intervals. As the oscillating plate 836 moves downward from the top of the apparatus, as seen in the left side of FIGURE 39, a portion of the housing 824 is no longer covered by the oscillating plate. This would permit grit and debris to possibly escape the interior chamber through the gap 662 necessary for passage of the nozzles. To resist this, a shield 924 is mounted on brackets 926 which are secured to pin 928. Pin 928 is the pin on which the housing section 604 pivots from the main frame. The shield 924 is a flexible sheet which is rolled on a roller 930 mounted between brackets 926 across the width of the oscillating plate 836. Brackets 926 are secured to the hinge pins on which oscillating frames 830 and 832 pivot and are therefore fixed relative frame 814. A spring, not shown, is mounted within the roller which normally forces the shield to roll up on the roller 930. However, the free end 932 of the shield is secured to the oscillating plate 836 by brackets 934 at either side of the plate 836. As the plate moves in an arc away from the top of the device, the free end 932 moves with the plate, unrolling portions of the shield from the roller to cover the exposed portions of the gap 662 to resist escape of debris from within the blasting chamber. As the oscillating plate moves back toward the top of the device, as seen in the right side of FIGURE 39, the shield 924 is rolled up on the roller 930 by the internal spring so that there is never any slack in the portion of the shield extended from the roller 930 to the brackets 934. Any debris impacting on the shield 924 will slide down in the gap between the oscillating plate 836 and the housing sections and will either return through slots 662 or fall into the collection pan 728. Although several embodiments of the invention have been described in the foregoing description and illustrated in the accompanying drawings, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications and substitution of parts and elements without departing from the spirit and scope of the invention.

Claims: A pipeline treating apparatus (600, 810) for treating pipeline (12, 812), comprising a mainframe (602, 814), a first housing section (604, 824) pivotally mounted on the mainframe extending about substantially one-half the circumference of the pipeline, a second housing section (606, 826) pivotally mounted on the mainframe extending about substantially the other half of the circumference of the pipeline, the first and second housing sections defining a chamber (608, 828) between the housing sections and the exterior of the pipeline, at least two nozzles (622, 911) mounted on the apparatus for discharging a treating media against the surface of the pipeline to remove debris from the surface of the pipeline, a classifier and separator unit (856) is mounted on the mainframe to separate the debris and the treating media to permit disposal of the debris and recycling of the treating media to the nozzles, characterized in that a first nozzle frame (610, 830) is pivotally mounted to the mainframe separately from the first housing section and extending about substantially one-half the circumference of the pipeline, a second nozzle frame (612, 832) is pivotally mounted on the mainframe separately from the second housing section extending about substantially the other half of the circumference of the pipeline, a first nozzle plate (614, 836) is mounted on the first nozzle frame for oscillating motion relative thereto, a second nozzle plate (618, 836) is mounted on the second nozzle frame for oscillating motion relative thereto, at least one nozzle is mounted on each of the nozzle plates for discharging a treating media against the surface of the pipeline, and at least one duct (844, 846, 848, 850) is connecting each of the housing sections with the classifier and separator unit to move debris and treating media from the chamber to the classifier and separator unit. The pipeline treating apparatus (600, 810) of Claim 1, further characterized in that each of the first (604, 824) and second (606, 826) housing sections includes a front end (640) and a rear end (638), a duct (846, 850) connecting the front end of each of the housing sections to the classifier and separator unit (856) and a duct (844, 848) connecting each of the rear ends of the housing sections to the classifier and separator unit. The pipeline treating apparatus (600, 810) of Claim 2, further characterized in that each of the ducts (844, 846) extending from the first housing section (604, 824) connect to a first housing section manifold duct (852), the first housing section manifold duct connecting to the classifier and separator unit (856), each of the ducts (848, 850) extending from the second housing section (606, 826) extending to a second housing section manifold duct (854), the second housing section manifold duct extending to the classifier and separator unit. The pipeline treating apparatus (600, 810) of Claim 1, further characterized in that the classifier and separator unit (856) is an inertial separator. The pipeline treating apparatus (600, 810) of Claim 1, further comprising a collection pan (726, 840) mounted between the first (604, 824) and second (606, 826) housing sections proximate the lower end of the pipeline treating apparatus, the debris separated by the classifier and separator unit (856) being returned to the collection tray. The pipeline treating apparatus (600, 810) of Claim 5, further characterized in that the first (604, 824) and second (606, 826) housing sections include at least first (648, 650, 876) and second (652, 654, 880) seals sealing against the exterior of the pipeline (12, 812), a chamber (646) being defined between the first and second seals, the chamber connected to the collection tray (726, 840) so that debris entering the chamber falls into the collection tray. The pipeline treating apparatus (600, 810) of Claim 6, further characterized in that the first (604, 824) and second (606, 826) housing sections further include a third seal (878) sealing against the exterior of the pipeline. The pipeline treating apparatus (600, 810) of Claim 1, further characterized by at least one vent mounted on each of the housing sections (604, 606, 824, 826), the vent including a filter (882) to prevent debris and treating media from escaping from the chamber (608, 828) to the exterior of the pipeline treating apparatus, the vent preventing overpressure of the chamber. The pipeline treating apparatus (600, 810) of Claim 1, further characterized in that each of the nozzles (622, 911) is mounted on the nozzle plate (614, 618, 836) by a snap fit connection (874). The pipeline treating apparatus (600, 810) of Claim 1, characterized in that a hose (870) is connected to each of the nozzles (622, 911) to supply the nozzle with treating media, a hose support (872) being mounted on the housing (602, 814) separated from the nozzle and supporting the hose as the nozzle is oscillated.

Inventors: ROGALA STANLEY J, STENZEL ANDRZEJ NMI, TAYLOR SIDNEY A, ROGALA, STANLEY J., STENZEL, ANDRZEJ, TAYLOR, SIDNEY A., Stenzel, Andrzej, (NMI)
Applicants: CRC EVANS REHABILITATION SYST, CRC-EVANS REHABILITATION SYSTEMS, INC.
Application year: 1995
Main classification: B08B9
IPC codes: B08B9, F16L45, B24C9, F16L1, B24C3