Abstract:
A high-pressure high-velocity target inserter for use in steam cleaning. The target inserter uses an actuator connected to a tube assembly, which connects to a test line. The target inserter uses packing to prevent high-pressure steam from being released through the target inserter when the target rod is inserted and withdrawn from the line. In the preferred embodiment, the target rod passes through a remotely operated actuator controlled valve and a remotely controlled actuator controller, such that the operator is kept a safe distance away from the inserter when the access valve to the line is open.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not applicable.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of Invention  
           [0004]    This invention relates to a method and device for determining the level of cleanliness in a pipe, conduit and the like. Specifically, the invention describes a target inserter for use with high-pressure high-velocity fluids (steam, liquid, air or similar cleaning fluids).  
           [0005]    2. Related Art  
           [0006]    Piping, conduits, vessels and similar structures are used in a variety of manners. Typically, such conduits are used to transport fluid materials, such as hydrocarbons, brine, and other liquids used in chemical and petrochemical processes. Similarly, such conduits may be used to transport fuels, including gas and liquid hydrocarbons. Conduits in other applications include those used to provide power steam in turbines. Typically, over time the interior surfaces of such piping frequently become coated with scale and other buildup of the transported material or its by-products. These deposits on the walls of the interior of the conduits pose a variety of problems, depending on the conduit and its use. For example, debris such as scale in a steam line may become dislodged, causing severe damage to steam turbine blades when struck by the entrained debris in the high velocity steam line. Buildup on the walls of piping in a heat exchanger reduce the efficiency in the heat transfer, including irregular heat transfer that may result in inefficient chemical reactions. Buildup on the walls of feedstock or fuel line in a petrochemical process may result in turbulence or blockage in the line, reducing the efficiency of the process until it is forced to shut down.  
           [0007]    In a petrochemical or similar processing unit, cleaning of the lines cannot be accomplished while the unit is in operation. The unit must be shut down for such maintenance, referred to typically as a “turnaround”. Normally closed loop systems are drained of their contents, purged if necessary, and cleaned out. A common method of cleaning out the lines is with high velocity steam. High temperature steam is flushed through the lines at high velocity, mechanically breaking off and flushing the built-up material on the wall interior. Cavitation often occurs as the high-velocity steam passes through the conduit, thus aiding in the breaking up of the build-up slag away from the vessel walls.  
           [0008]    In the prior art, such as described by Bloch in U.S. Pat. No. 4,853,014, low-pressure high-velocity steam is used for interior cleaning of pipes. Pressure is built up in a boiler, and then released through the lines to be cleaned. The lines are then allowed to cool while steam pressure is built up again in the boiler. This blow cycle is repeated until the line is clean. To determine if the steam (and therefore the line) is clean, a piece of soft metal called a target is supported across the interior of the terminal portion of the line. The target is inserted into the line (typically between blow cycles), steam is blown through the line, and the target then removed. Pits in the metal target are caused by debris from the line striking the metal. These pits are counted to quantify the level of cleanliness of the line. When the line is still “dirty”, numerous pits are observed. As the line becomes cleaner, there are fewer small debris particles being pushed by the steam, and thus there are fewer pits in the target. The steam is then vented out the line through an expansion chamber, into which Bloch introduces a decelerating mist for noise control. While this method takes advantage of the flushing and cavitational forces provided by steam at near sonic velocity, being at low pressure requires a high volume of water to adequately flush out the line. Further, target insertion/removal must be performed at low pressure, typically between blow cycles, due to the prior art design limitations of the target inserter. Finally, the steam can only be used in a single unit, since there is inadequate pressure to pipe the steam to a second unit to clean it as well.  
           [0009]    A preferred method of cleaning pipes, conduits and like devices is to use a high-pressure high-velocity gas stream, typically steam. While the term “steam” will be used throughout the description of the prior art and this invention, it is understood that “steam” is to encompass all similar gas streams used in the context of pressure cleaning.  
           [0010]    Using a high-pressure gas stream offers several advantages over low-pressure. First, since most systems being cleaned normally operate at high pressure, they respond best to a high-pressure cleaning gas stream. Such systems often have bends and recesses in their interior structure of the conduits. As such, the normal fluid traveling through the piping hits and impinges on areas within the conduit that may be restricted. A low-pressure gas stream will not invade such spaces, but will pass over these areas. Therefore, a high-pressure gas stream that mimics the pressure and characteristics of the material within the conduit during normal operation will provide better cleaning access to all areas within the conduit. Second, low-pressure gas streams rely heavily on the force of relatively high volume of water to flush out the conduit being cleaned. The water used is typically demineralized, and is relatively expensive compared to untreated water. Further, this high volume of water must be treated after being flushed through the conduit, which often contains hazardous materials. Treatment of this effluent water is often expensive and resource consuming. Finally, high-pressure steam can be used to clean more than one unit. By connecting more than one unit of conduits with a temporary connection line, steam used to clean the first unit can continue through the temporary connection to flush through the second unit.  
           [0011]    While the advantages of using high-pressure high-velocity steam are clear, such steam has not been used due to technical and safety problems associated with the target. As described above, a target is used to determine the cleanliness of the conduit by determining the cleanliness of the steam. By determining the cleanliness of the steam, it is assumed that the interior of the conduit being cleaning is analogously clean, having had all friable and loose scale knocked off by the steam. When using the same steam to clean a second unit that was used in a first unit (using temporary connection piping as described above), a method and device are needed to determine the cleanliness of the first unit as well as the second unit. If the target is only placed at the exit of the second unit piping, the source of debris causing pitting on the target is unknown, since it could come from the first unit or the second unit. Thus a target inserter between the first unit and second unit is needed to measure the cleanliness of the first unit. The cleanliness of the second unit is then determined by subtracting the number of pits from the first unit&#39;s target from the number of pits from the second unit&#39;s target.  
           [0012]    It would therefore be useful improvement of the prior art of target inserters to be able to function in a high-pressure high-velocity steam environment while the cleaning system is still under high pressure.  
         BRIEF SUMMARY OF THE INVENTION  
         [0013]    Accordingly, the objectives of this invention are to provide, inter alia, a new and improved target inserter for use in determining the cleanliness of a pipe, conduit and like device being cleaned by a high-pressure high-velocity gas stream cleaning system. These objectives include having a device and system that:  
           [0014]    operates at high pressure;  
           [0015]    utilizes standard metal targets and target rods;  
           [0016]    can be remotely operated for increased safety; and  
           [0017]    connects to standard pipe flanges and valves.  
           [0018]    These objectives are addressed by the structure and use of the inventive device. Other objects of the invention will become apparent from time to time throughout the specification hereinafter disclosed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 depicts the preferred embodiment of the inventive high-pressure target inserter.  
         [0020]    [0020]FIGS. 2A and 2B depict a coupler for connecting a target rod and an actuator rod.  
         [0021]    [0021]FIGS. 3A and 3B depict a sleeve assembly for holding a target rod.  
         [0022]    [0022]FIGS. 4A and 4A depict a target rod.  
         [0023]    [0023]FIG. 5 depicts a shell assembly, including a sleeve assembly and connection flanges.  
         [0024]    [0024]FIG. 6A depicts a packing head used in a shell assembly.  
         [0025]    [0025]FIG. 6B depicts a packing gland used with a packing head for pressing packing against a target rod.  
         [0026]    [0026]FIG. 7 depicts in graphic and illustrative form the inventive target inserter used in the preferred embodiment between two units being cleaned by the same high-pressure high-velocity gas. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    The present invention is described as target inserter  10 , depicted in the preferred embodiment in FIG. 1.  
         [0028]    Actuator  40  is attached to sleeve assembly  50 . Shell assembly  45  includes sleeve assembly  50 , which has a first end and a second end. The first end of shell assembly  45  connects to actuator  20 . In the preferred embodiment, this attachment is accomplished by bolting actuator flange  40  to actuator adapter flange  52 , which is preferably a  150 # flange welded to sleeve assembly  50 . The second end of shell assembly  45  is connected either directly or indirectly to pipe  80 . If directly connected, the second end of shell assembly  45  is connected to a flange welded to the side wall of pipe  80 , the flange being circumferential to an opening in the wall of pipe  80 . If indirectly connected to pipe  80 , as in the preferred embodiment, the second end of shell assembly  45  is connected to a valve  70 , which is bolted to the flange welded to the side wall of pipe  80 . This valve  80  has flanges on each end allowing it to be bolted to the pipe flange and packing gland housing flange  66 , which is located at the second end of shell assembly  45 , as depicted in FIG. 1. Actuator piston  30  is connected to actuator/rod coupling  54 , located within shell assembly  45  as shown in FIG. 1. Actuator/rod coupling is shown detail in FIGS. 2A and 2B. Typically, actuator piston  30  is connected to actuator/rod coupling  54  by screwing actuator piston  30  into actuator piston receiving threaded hole  59  of actuator/rod coupling  54  until tight.  
         [0029]    Actuator  20  comprises actuator piston  30 , which is oriented within actuator housing  32 . Actuator piston  30  comprises actuator piston rod  36 , which attaches at one end to actuator/rod coupling  54 , and at the other end connects to actuator piston head  34 . Between actuator piston head  34  and actuator end cap  23  is actuator extend air inlet  29 . Actuator extend air inlet  29  is connected to extend pneumatic hose  28 , which connects to actuator controller extend air outlet  27 . Actuator extend air inlet  29 , extend pneumatic hose  28  and actuator controller extend air outlet  27  provide pneumatic communication between actuator pneumatic controller  21  and the cavity interior to actuator housing  32  between actuator piston head  34  and actuator end cap  23 .  
         [0030]    Actuator cylinder seal  38  is located in the interior of actuator  20 , and provides a pneumatic seal between the interior of actuator housing  32  and actuator flange  40 , while allowing passage of actuator piston  30  therethrough. Between actuator piston head  34  and actuator cylinder seal  38  is actuator retract air inlet  26 . Actuator retract air inlet  26  is connected to retract pneumatic hose  25 , which connects to actuator controller retract air outlet  24 . Actuator retract air inlet  26 , retract pneumatic hose  25  and actuator controller retract air outlet  24  provide pneumatic communication between actuator pneumatic controller  21  and the cavity interior to actuator housing  32  between actuator piston head  34  and actuator cylinder seal  38 .  
         [0031]    Actuator pneumatic controller  21  is a standard pneumatic controller having actuator controller air inlet  22 , actuator controller retract air outlet  24 , actuator controller extend air outlet  27  and means for directing pressurized air coming into actuator controller air inlet  22  to actuator controller retract air outlet  24  or actuator controller extend air outlet  27 . When pressurized air is directed to actuator controller extend air outlet  27 , pressure from retract pneumatic hose  25  and actuator retract air inlet  26  is allowed to bleed off through actuator controller retract air outlet  24 . Conversely, when pressurized air is directed to actuator controller retract air outlet  24 , pressure from extend pneumatic hose  28  and actuator extend air inlet  29  is allowed to bleed off through actuator controller extend air outlet  27 . For safety purposes, this transition between pressurizing and bleeding off pressure between the retract and extend systems is gradient, to that the rate of extension/retraction can be controlled, preventing a “blow-out” of the actuator piston from uncontrolled pressure against target rod  56 .  
         [0032]    Target rod  56  is attached to target rod receiving threaded hole  61  of actuator/rod coupling  54 , as shown in FIG. 1. Details of actuator/rod coupling  54  are shown in FIGS. 2A and 2B. Actuator/rod coupling  54  has three threaded holes. The first is actuator piston receiving threaded hole  61 , into which actuator piston rod  36  is screwed. The preferred dimensions of actuator piston receiving threaded hole  59  are approximately 1¼″-12 THD×1⅛″ deep. The second is target rod receiving threaded hole  61 , into which target rod  56  is screwed, being axial with actuator piston receiving threaded hole  61  and actuator piston rod  36 . The preferred dimensions of target rod receiving threaded hole  61  are approximately 1″-12 THD×1⅛″ deep. The third is flag bolt receptor  53 , which is cut into the top rounded surface of actuator/rod coupling  54 , and oriented normal to target rod receiving threaded hole  61 . In the preferred embodiment, flag bolt receptor  53  is a threaded hole, having preferred dimensions of approximately ½″-13 THD×¾″ deep. Flag bolt receptor  53  receives flag bolt  55 .  
         [0033]    Flag bolt  55  serves two main purposes. First, it prevents rotation of actuator/rod coupling  54 , so that actuator piston  30  and/or target rod  56  do not become unscrewed by such rotation. Second, flag bolt  55  serves as a visual indicator showing if target  58  is inserted within test pipe  80 . Flag bolt  55  traverses through flag bolt slot  51 , shown in FIGS. 3A and 3B. Flag bolt slot  51  is a slot, preferably approximately ½″ wide, oriented along the longitusdinal axis of sleeve assembly  50 . When target  50  is inserted into pipe interior  85  of pipe  80 , flag bolt  55  is in a first position proximate pipe  80 . When target  50  is withdrawn from pipe interior  85 , flag bolt  55  is in a second position distal pipe  80 . Thus a quick visual reference is provided to show if it is safe to open or close valve  70  depending on where target  58  and target rod  56  are oriented.  
         [0034]    Target rod  56 , shown in detail in FIGS. 4A and 4B, is oriented along the central axis of the longitudinal interior of shell assembly  45 . Shell assembly  45 , depicted in detail in FIG. 5, comprises sleeve assembly  50 , packing head housing  65 , actuator adaptor flange  52  and target access  47 . Target access  47  is a void cut into at least one side of sleeve assembly  50 , and allows access to target recess  57  for connecting, typically with screws, target  58  to target rod  56 . Target rod  56  is preferably comprised of a strong metal, such as 4140 stress relieved steel. Target rod  56  comprises a threaded end for attachment to actuator/rod coupling  54  as described above, plus a target recess  57 . Target recess  57  has a flat surface, against which target  58  mates and is attached, typically with screws into threaded holes located in the flat surface of target recess  57 . To provide access to target recess  57 , target rod  56  is aligned as in FIG. 1, such that target recess  57  faces out through a target access  47 .  
         [0035]    Target rod  56  traverses through packing head  60 , which is oriented at the end of shell assembly  45  proximate to an opening in a wall of pipe  80  and distal to actuator  20 . Packing head  60  comprises packing gland  62 , packing cavity  63 , packing  64 , packing gland housing  65 , and packing gland housing flange  66 . Packing  64 , typically multiple packing rings, is oriented within packing cavity  63  and circumferentially around target rod  56 . Packing gland flange  67  of packing gland  62  bolts onto packing head  60  of into packing gland housing  65 , such that packing gland sleeve  68  inserts into packing cavity  63  of packing gland housing  65 , thus pressing packing  64  against target rod  56  when tightened. The preferred embodiment of packing gland housing  65  and packing gland  62  are depicted in FIGS. 6A and 6B. Packing gland housing flange  66  connects, typically with bolts, to valve  70 , which is connected to pipe flange  82 . Pipe flange  82  is oriented axial to an opening in the wall of pipe  80 . Target rod  56  and target  58  are able to traverse through valve channel  72  when valve  70  is open. Valve  70  is typically a gate valve. In the preferred embodiment, valve  70  is opened and closed by a remotely controlled valve actuator, to provide additional safety to the operator. Alternatively, shell assembly  45  can be attached directly to an opening in the wall of pipe  80  where there is a point of attachment, such as a flange, attached directly to the side of pipe  80  around the wall opening. However, this alternatively embodiment does not offer the same safety advantage offered by the use of valve  70  as an attachment to pipe  80  for access to pipe interior  85 .  
       OPERATION  
       [0036]    Target inserter  10  may be used in any steam cleaning system, including those using high-pressure high-velocity steam. In the preferred embodiment shown in FIG. 7, target inserter  10  is connected to pipe  80 , which is a temporary connection between Unit  1  and Unit  2 . Unit  1  and Unit  2  are any systems having piping, conduit, vessels and the like to be cleaned by high-pressure high-velocity gas such as steam. High-pressure high-velocity steam is introduced into the piping system of Unit  1 . This steam exits Unit  1  into temporary pipe  80 . The steam (still at high-pressure and high-velocity) then enters the piping system of Unit  2 , from which the steam ultimately exhausts to the atmosphere or a retention system (in the case of hazardous materials in the units). The high-pressure high-velocity steam travels through the piping of Unit  1 , cleaning out debris from the interior walls of the piping. This steam and its accompanying debris flush through the piping of Unit  1 , through temporary pipe  80 , and then through the piping of Unit  2 .  
         [0037]    To determine the cleanliness of the steam exiting Unit  2 , the inventive target inserter  10  or a prior art inserter typically may be used, since the steam being exhausted from Unit  2  is typically at low pressure. To determine the cleanliness of steam exhausting from Unit  1  and passing through temporary pipe  80  to Unit  2 , inventive target inserter  10  must be used, since the steam is still at high pressure.  
         [0038]    Target inserter may be used where pressure exceed normal steam blow cleaning pressures of 10 to 75 PSIG. Target inserter  10  will function at pressures up to 600 PSIG and maintain operator safety by sealing escaping steam via packing  64 , and thereby preventing blowback. To assemble target inserter  10 , actuator  20  is first attached to shell assembly  45  by connecting, typically with bolts, actuator flange  40  and actuator adapter flange  52 . In the preferred embodiment, actuator adapter flange  52  is a 3″-150 flange. Using low-pressure air, actuator piston rod  36  is extended by directing air through actuator pneumatic controller  21  to actuator extend air inlet  29 . The threaded end of actuator piston rod  36  is screwed into actuator piston receiving threaded hole  59  of actuator/rod coupling  54  and tightened. Actuator piston  30  is then retracted into actuator  20 . Packing  64  (typically multiple rings of packing) are inserted into packing cavity  63  and packing gland  62  is lightly attached to packing head  60 . The threaded end of target rod  56  is passed through packing head  60  and screwed into target rod receiving threaded hole  61  of actuator/rod coupling  54 . Actuator/rod coupling  54  is oriented such that flag bolt receptor  53  is normal to flag bolt slot  51 , and flag bolt  55  is then inserted and tightened into flag bolt receptor  53  on actuator/rod coupling  54 . Target rod  56  is aligned such that target recess  57  is oriented outward through target access  47 . Packing gland  62  is then tightened until it gently squeezes target rod  56 .  
         [0039]    Packing gland housing flange  66  is then attached to closed valve  70 . Target  58  is attached to target rod  56  in target recess  57 . Pressurized air is connected to actuator controller air inlet  22  while actuator pneumatic controller  21  is in the “Retract” position. Target inserter is now ready for use.  
         [0040]    Closed valve  70 , attached to pipe  80 , is opened, preferably remotely using a standard remote controlled valve actuator mechanism. Actuator  20  is extended, pushing target rod  56  and target  58  through the valve channel  72  of open valve  70 , and then into pipe interior  85  of pipe  80 . Target  58  is oriented normal to the flow path of the high-pressure high-velocity steam in pipe  80 . Thus the steam and debris particles carried by the steam impinge against target  58 , forming a quantifiable number of pits in target  58 . After a determined length of time, actuator pneumatic controller  21  is engaged to retract target rod  56  and target  58  out of pipe interior  85  and through valve channel  72 . After retraction, valve  70  is closed for additional safety, and target  58  removed for analysis. A fresh target  58  is installed, and the process repeated until the high-pressure high-velocity steam and lines it has cleaned are determined to be adequately clean.  
         [0041]    The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.