Abstract:
A reformer tube processing and filling system is provided for ensuring uniformity of reformer tube flow rates and reactivity. The disclosed invention provides a system for detecting and removing tube obstructions, as well as an automated process for verifying the flow rate for each tube and identifying tubes with abnormal flow rates to remove a source of human error and conserve labor costs. An automated tube filling system provides a calibrated fill mechanism coordinated with a calibrated loading rope withdrawal mechanism to ensure loading consistency. A lack of vibrating parts ensures a low dust count, and what little dust is present is removed via a built-in vacuum outlet in the loader.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a divisional of U.S. patent application Ser. No. 12/617,461 filed Nov. 12, 2009, which is a continuation-in-part of U.S. application Ser. No. 12/599,777, filed Mar. 12, 2010, now U.S. Pat. No. 8,011,393, issued Sep. 6, 2011, which claims the benefit of U.S. Provisional Patent Application No. 61/116,140, filed Nov. 19, 2008, and is the national phase of and claims priority on PCT/EP2008/006646, filed Aug. 13, 2008, which in turn claims priority on Netherlands Patent 1034249, filed Aug. 13, 2007, all of which are incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a method and apparatus for filling particulate material into tubes, and more particularly, to catalyst processing and the loading of particulate catalyst material into reformer tubes with a uniform density. 
       BACKGROUND OF THE INVENTION 
       [0003]    Catalytic processing is required to execute certain material processing tasks such as chemical refinement of fluid and gaseous materials. For example, in the process of catalytic cracking for petroleum refinement, it is common to use a catalytic material to facilitate the desired cracking or other transformation. Typically, the material to be refined is directed through an appropriate catalytic material until a certain level of transformation has occurred. Because the catalytic efficiency of the system is strongly related to the frequency with which molecules or particles of the starting substance interact with the catalyst, the industry has adopted a practice of performing such catalytic processes in long tubes. In particular, the starting material is forced through a set of parallel tubes, each containing the catalyst material at a predetermined desired density, e.g., particles per unit volume or weight per unit volume. 
         [0004]    The flow rate of the material through the system is equal to the sum of the flow rates through the multiple tubes, however, it is possible for one or more tubes to exhibit lower flow rates than other tubes. Lower flow rates generally are due to clogging or overfilling of the tubes, which can have the deleterious effect of prematurely exhausting or damaging the tubes with higher flow rates. Because catalytic refineries typically are run nonstop, it is expensive to shut the process down prematurely to service the catalyst tubes; maintenance on the tubes is ideally only performed once in the course of several years. Thus, the loading of the catalyst tubes is a critical step, and the failure to properly execute this step can cause the process operator to incur financial losses due to lost production during repair as well as increased labor costs to execute the repairs. 
         [0005]    A properly prepared set of catalyst tubes will have relatively uniform resistance to flow from tube to tube, thus ensuring uniform flow rates, and will also have a relatively uniform density of catalyst from tube to tube, thus ensuring the same degree of product transformation for each tube. Thus, the tubes must be properly checked, cleaned, and filled with catalyst. Existing cleaning and filling protocols are subject to high cost and frequent human error due to their use of numerous personnel in time-consuming tasks. Although attempts have been made to solve the foregoing problems, a solution has not yet been devised that fully addresses the concerns without introducing further significant problems or costs. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0006]    It is an object of the present invention to provide a system for ensuring tubes are in optimal condition for automated uniform filling of particulate material, and particularly particulate catalyst material. 
         [0007]    Another object is to provide an automated loading system for more quickly and uniformly directing the particulate material into reformer tubes. 
         [0008]    In carrying out the invention, a reformer tube processing and filling system is provided for ensuring uniformity of reformer tube flow rates and reactivity. With respect to ensuring uniform flow rates, the subject invention provides a system for detecting and removing tube obstructions, as well as for verifying the flow rate for each tube and identifying tubes with abnormal flow rates. The verification process may be automated, thus removing a source of human error, and conserving labor costs. 
         [0009]    With respect to ensuring uniform reactivity, an automated tube filling system is provided. The automated tube filling system provides a calibrated fill mechanism coordinated with a calibrated loading rope withdrawal mechanism to ensure loading consistency. A lack of vibrating parts ensures a low dust count, and what little dust is present may be removed via a built-in vacuum outlet in the loader. 
         [0010]    Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a simplified schematic view of a set of reformer tubes with respect to which the invention may be used; 
           [0012]      FIG. 2  is cross-sectional side view of a contaminated reformer tube undergoing laser analysis for volume determination according to an embodiment of the invention; 
           [0013]      FIG. 3  is a simplified schematic view of an automated flow rate check system for checking tube flow rates according to an embodiment of the invention; 
           [0014]      FIG. 4A  is a flow chart illustrating an automated flow rate check process for execution via a computer according to an embodiment of the invention; 
           [0015]      FIG. 4B  is a flow chart illustrating a process for checking and filling a catalyst tube in an embodiment of the invention; 
           [0016]      FIG. 5  is a perspective of an illustrated catalyst tube loading system in accordance with the invention; 
           [0017]      FIG. 6  is a perspective of the illustrated catalyst loading system with portions broken away; 
           [0018]      FIG. 7  is an enlarged perspective of the catalyst containing hopper and dispensing device of the illustrated loading system; 
           [0019]      FIG. 8  is a vertical section of the catalyst hopper and dispensing device shown in  FIG. 7 ; 
           [0020]      FIG. 9  is an enlarged perspective of the loading rope lifting device of the illustrated dispensing system; 
           [0021]      FIG. 10  is a perspective of the lifting device shown in  FIG. 9  with portions broken away; 
           [0022]      FIG. 11  is an enlarged perspective of the loading rope take up spool of the illustrated lifting device; and 
           [0023]      FIG. 12  is a perspective of a loading rope guide spool of the illustrated loading rope lifting device. 
       
    
    
       [0024]    While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention. 
       DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Referring now more particularly to  FIG. 1 , there is schematically shown, a portion of an exemplary reformer tube set  100  within which the present invention may be implemented to provide a uniform flow rate and processing efficiency. The exemplary tube set  100  includes numerous individual tubes  101 , each being filled with a catalyst material to receive an incoming flux  103  of raw material and to provide an outgoing flux  105  of processed material. It will be appreciated that the processed material may include a desired material as well as byproducts of the reformation process. Moreover, it will be appreciated that the illustrated tube set  100  is shown in simplified form for the purpose of clarification, and that an actual reformer tube set may include a greater or lesser number of tubes, e.g., from 1 to 1000 tubes, and each tube will typically be of a much greater length relative to its width than is illustrated. For example, typical reformer tubes are between 10 and 16 meters in length. 
         [0026]    To minimize maintenance and idle costs associated with the operation of the tube set  100 , it is desirable to ensure that each tube  101  is loaded with catalyst (not shown in  FIG. 1 ) to a uniform density and that each tube  101  is of similar flow resistance. This will ensure that the incoming flux  103  of raw material is divided equally among the tubes for processing. In particular, the proportion of the incoming flux  103  of raw material that is allocated to each tube  101  will depend, according to the laws of parallel resistance, upon the relative differences in resistance to flow between the tubes  101 . If there are no substantial differences in flow resistance across the tube set  100  from tube to tube, then the incoming flux  103  of raw material will be divided equally among the tubes  101  of the set  100 . 
         [0027]    As noted above, the parameters that affect flow rate and processing efficiency for each tube are flow resistance, tube volume, and catalyst density. Although these parameters are not entirely dependent, each will be addressed separately herein for the sake of clarity. Those of ordinary skill in the art will appreciate the degree to which and manner in which each of these parameters may affect the others. 
         [0028]    Pursuant to one aspect of the invention, in order to ensure uniform flow resistance across the tubes  101  of the tube set  100 , each tube  101  is checked for contaminating deposits and is cleaned if necessary. In an embodiment of the invention, empty tubes are first inspected for contamination. In an particular embodiment of the invention, the inspection mechanism is a video camera mounted on an extended flexible member such as a rod, for lowering into the tube of interest. In an alternative embodiment of the invention, the inspection mechanism comprises a laser sensor to measure the total amount of foreign matter in the tube. 
         [0029]    Referring now more particularly to  FIG. 2 , a cross-sectional side view of a contaminated tube  200  is shown. In the illustrated example, the tube wall  201  is contaminated by multiple deposits  203 ,  205  of byproduct materials. In the case of petroleum refinement, the deposits  203 ,  205  may be tar-like deposits, sulfur or other mineral deposits, or other byproduct or contaminant substances. 
         [0030]    In the illustrated embodiment of the invention, a laser sensor system  207  is used to analyze the content of the tube. The laser system  207  may be a scanning or sweeping laser system, or other system configured to analyze substantially all of the interior of the tube  200 . The laser sensor system  207  in an embodiment of the invention determines the volume of the tube  200  that is displaced by the deposits  203 ,  205 . Although very small deposits need not be removed, it is desirable to clean the tube  200  if the amount of contaminant displacement exceeds a certain threshold, e.g., 5% of the nominal volume of the tube  200 . Those of skill in the art will be aware of the means available to remove contaminant deposits such as those illustrated in  FIG. 2 , and these means need not be further discussed herein. 
         [0031]    In order to ensure uniform processing, each tube  200  is checked for flow resistance after the removal of any deposits to the extent such is required. Referring now to  FIG. 3 , each tube  200  is connected to a flow checker system  300  to check the flow resistance. The flow checker system  300  comprises a computer  301 , an airflow source  303  connected to the computer  301  so as to be computer-actuated, and a flow and/or pressure sensor  305 , e.g., a manometer, connected to the computer  301  so as to be computer readable. 
         [0032]    In operation, the airflow source  303  is mechanically connected to the tube  200  (with the deposits  203 ,  205  having been removed). At this point, the computer  301  executes a program, e.g., a body of computer-executable instructions stored on a computer-readable medium such as a hard drive, to verify the flow resistance of the tube  200 . 
         [0033]    The flow checker process executed by the computer  301  is illustrated via process  400  in the flow chart of  FIG. 4A . At stage  401  of the process  400 , the computer  301  actuates the airflow source  303 , e.g., via a digital relay, to force air through the tube  200 . As the air passes through the tube  201 , the manometer or other flow and/or pressure sensor  305  is caused to measure the flow resistance of the tube  201  at stage  403 . For example, the computer  301  may read a digital or analog output of the sensor  305  at this stage. The measurement of the flow resistance will be based upon a difference in pressure or flow caused by any obstruction. For example, a tube  201  with a partially obstructed output, and hence higher flow resistance, will exhibit both decreased flow and increased pressure relative to a similar tube without any obstruction. The computer  301  optionally repeats the measurements at either the same or different input conditions at stage  405 . 
         [0034]    At stage  405 , the computer  301  logs the measured values in a chart, e.g., an EXCEL chart or other chart. After a desired number of tubes have been analyzed, e.g., one hundred tubes, the computer  301  identifies in stage  407  via a chart or listing any tubes that fall outside of a predetermined range or variance relative to the other tubes analyzed. For example, the computer  301  may list as abnormal any tube that exhibits a flow resistance that is more than 5% different from the average flow resistance of the set of tubes. 
         [0035]    The overall process of filling, incorporating the procedure of  FIG. 4A , but also incorporating additional processes, will now be discussed with reference to  FIG. 4B . The illustrated combined process  450  starts at a time when the catalyst tubes are empty, either because they are new tubes or because they have been recently emptied and cleaned. At stage  451 , the tube is video inspected to determine whether closer scanning of the tube is to be performed. Any manner of video inspection may be used, but in an embodiment of the invention, a video camera is lowered on an arm or wire the tube interior, and transmits video of the surface under inspection to a video display, such as a small monitor or laptop computer outside the tube. 
         [0036]    If such inspection reveals that scanning necessary, e.g., because there are ambiguous video inspection results that may or may not indicate contamination, then the process proceeds to stage  453 . At stage  453 , the tube interior is closely scanned to identify dirt or contamination deposits that may need to be removed. Although any suitable scanning means may be used, in an embodiment of the invention, such scanning is executed via a rotating laser scanner lowered into the tube interior. The laser scanner measures the inside radius of the tube, to detect any deposits therein. 
         [0037]    If the scanning of stage  453  reveals depots to be removed, the process flows stage  455 . At stage  455 , the tube inside wall is cleaned. Although any suitable process of cleaning may be used, in one embodiment, the cleaning is executed via a brushing device inserted into the tube, for accomplishing mechanical, e.g., abrasive, removal of any identified deposits. The cleaning may focus only on identified deposits or may be executed uniformly within the tube. 
         [0038]    After cleaning is accomplished at stage  455 , or in the event that either of stages  451  or  453  resulted in a decision that no scanning or cleaning, respectively, was needed, the process flows to stage  457 . At stage  457 , the pressure drop through the tube is measured. Although it will be appreciated that there are several ways to measure such a pressure drop, the pressure drop is measured in one embodiment of the invention via the apparatus described with reference to  FIG. 3 . 
         [0039]    After the pressure drop is initially measured, the tube is filled with catalysts and the pressure drop again measured in stage  459 . The loading of stage  459  may be executed via the loading mechanism described below or via another mechanism. Finally, at stage  461 , the average pressure drop across a plurality of such filled tubes for parallel use as in  FIG. 1  is calculated, and it is verified that the reading for the present tube is within a predetermined variance of that average. In an embodiment of the invention, a variance of ±2% is used to indicate a maximum acceptable deviation from the average. If the pressure reading for the tube is within the accepted level, then the process terminates, and otherwise, any necessary corrective action such as emptying, rechecking, and refilling, are executed as necessary. 
         [0040]    Referring now more particularly to  FIGS. 5-6  of the drawings, there is shown an illustrative automated catalyst loading system  500  in accordance with the invention that is adapted for automatically filling the cleaned and checked tubes, such as tube  201  in stage  459  of process  450 , with particulate catalyst of uniform density and with minimum damage to catalyst particles and tube structures. The illustrated automated loading system  500  includes a fork fill tube  501  having a vertically disposed connecting tube portion  502  mounted on and communicating with an upper end of a reformer tube  201  to be filled and a fill tube portion  504  supported by and communicating at an angle with a side of the vertical connecting tube portion  502 . The vertical connecting tube portion  502  and the reformer tube  201  have respective lips  505 , 506  which define a coupling joint for facilitating releasable securement of the tubes  201 , 501  together. 
         [0041]    For directing particulate catalyst into the forked fill tube  501  and in turn into the reformer tube  200  for continuous uniform filling, a selectively operable motor driven catalyst dispenser  510  is provided. The catalyst dispenser  510  includes an open top hopper  511  for holding a supply of catalyst  512  which in this case has a support frame or structure  513  at one end to facilitate mounting of the hopper  511  in a processing facility. The bottom of the hopper  511  is defined by an endless conveyor belt  514  trained about a pair of horizontally spaced drums or pulleys  515 ,  516  such that an upper leg of the endless belt  514  extends along a bottom opening  518  of the hopper  511 . The drums or pulleys  515 , 516  in this instance are rotatably supported by underlining frame members  520  of the hopper  511 . For moving the conveyor belt  514  to transfer catalyst  512  from the hopper  511 , a drive motor  521  is operably coupled to the pulley or drum  515 . Operation of the motor  521  will thereby direct catalyst from the hopper to a downstream end of the conveyor belt  514  (i.e., the right hand end as viewed in  FIGS. 7-8 ) for direction into a discharge shoot  522  defined by a semi-circular cover  524  mounted at one end of the hopper  511 , and in turn its an upper end of the fill tube portion  504  and the reformer tube  200 . 
         [0042]    For controlling the flow of catalyst  512  introduced into the reformer tube  200 , a loading rope or line  530  is suspended within the reformer tube  200  for lifting movement as the catalyst fills the tube. The loading rope  530  may be of a known type having damper members  531  in the form of a plurality of radially extending transverse bristles disposed at spaced intervals along the rope. The brush bristles of the damper members  531  preferably are flexible springs having a transverse radial dimension slightly less than the radius of the reformer tube  200  for reducing the speed of the falling catalyst particles so that breakage is avoided and the catalyst more uniformly fills the tube without undesirable voids. 
         [0043]    In keeping with a further aspect of the loading system, for further facilitating the efficient and uniform introduction of catalyst  512  into the reformer tube  200 , an automatic loading rope take-up device  540  is provided for withdrawing the loading rope  530  from the reformer tube  200  at a predetermined rate. To this end, in the illustrated embodiment, the take-up device  540  includes a motor driven take-up spool  541  to which an upper end of the loading rope  530  is secured such that upon selective rotation of the take-up spool  541 , the rope  530  is wound about the take-up spool  541  as it is raised from the reformer tube  200  at a predetermined calibrated rate as determined by the rotational speed of the take-up spool  541 . 
         [0044]    The take-up spool  541  in this case is rotatably mounted in a frame  542  which can be appropriately mounted in the processing facility, such as by hanging from the ceiling by an upstanding hook  544  mounted on the upper most end of the frame  542 . The illustrated take-up spool  541  comprises an inner cylindrical hub  544  to which laterally spaced circular side plates  545  are fixed, and a plurality of circumferentially spaced rods  546  are interposed between the side plates  545  in outward radial relation to the inner hub  544  which define an interrupted, non circular, winding surface of the drum. 
         [0045]    For rotating the take-up spool  541 , the central hub  544  has a drive shaft  548  which is driven by a drive motor  549  mounted on the frame  542  via a drive belt or chain  550 . With an upper end of the loading rope  530  secured to the take-up spool  541 , rotation of the take-up spool  541  by the drive motor  549  will cause the take-up rope to be wound upon the take-up drum and raised from the reformer tube at a predetermined rate governed by the operating speed of the motor  549 . The plurality of circumferentially spaced rods  546  that define the effective non-circular winding surface of the take-up spool  541  cause the loading rope  530  to be raised with irregular movement for preventing build-up of catalyst on the damper members  531 , while also facilitating positioning of the damping members  531  in flattened positions on the take-up spool  541  during such rotary take-up movement. 
         [0046]    To further facilitate continuous loading of catalyst into the tube without undesirable build-up of catalyst on the loading rope  530 , the loading rope  530  is trained about a rotatable eccentric spool  560  disposed adjacent the take-up spool  541  which is effected for successively causing the rope to swing or move up and down as it is drawn onto the take-up spool  541 . The eccentric spool  560  in this case comprises a central rotatable drive shaft  561 , a pair of laterally disposed circular side plates  562  mounted on the drive shaft central hub  563 , and a pair of diametrically opposed rods  564  disposed between the side plates  562  outwardly of the drive hub  563 . Rotation of the eccentric drive spool  560  by a drive belt or chain  566  coupled to the output shaft  551  of the drive motor  549  will cause the eccentric spool  560  to rotate simultaneously as the take-up spool  541  rotates to lift the loading rope  530  from the reformer tube  200 . The diametrically opposed rods  564  of the rotating eccentric spool  560  successively engage and swing the loading rope  530  in up and down fashion to dislodge and prevent accumulation of catalyst on the damper members  531  as the rope  530  is raised from the reformer tube  200 . 
         [0047]    In accordance with a further important aspect of the catalyst loading system  500 , a control is provided for controlling operation of the drive motors  521  and  549  such that loading rope  530  is raised from the reformer tube in calibrated synchronized relation to the operating speed of the feed conveyor belt  514  for ensuring continuous, uninterrupted loading of catalyst with enhanced uniformity. To this end, operation of the motors  521 , 549  may be driven under the control of a computer such as the computer  301 , or such other computer  570  dedicated exclusively to the drive motors  521 , 549 . Within the computer  301  and/or  570 , computer-readable code stored on a computer-readable medium such as a disc or drive is read and executed by the computer processor. Such code acts to operate the drive motors  521  and  549  in a synchronized manner via suitable output drivers such as a digital to analog converter or transducer. The motor synchronization may be based either on empirical data regarding flow rates and settling and the like, or via feedback that adjusts the relative speeds of the motors based on the actual instantaneous fill level within the tube. In the latter case, detection of fill level may be via optical measurement or other suitable measurement technique. 
         [0048]    As will be understood by a person skilled in the art, the loading rope  530  should be raised at a rate such that the lower-most damping member  531  of the loading rope  530  is raised from the reformer tube  200  at a speed such that it stays just above the level of catalyst deposit in the tube. More importantly, by means of the computer control, the rate at which the loading rope  530  is lifted from the reformer tube  200  is synchronized with the speed of the loading conveyor belt  514  for the particular loading operation. In each case, continuous loading of catalyst into the reformer tube  200  permits quicker, more uniform filling of the tubes. Indeed, the possibility of human error associated with conventional practices of filling reformer tubes is eliminated since a large number of tubes may be loaded in exactly the same manner and speed, resulting in uniformity of the filled tubes  200  and reduced pressure drop variations therein. The catalyst loading system  500  of the present invention has been found to enable up to 20% faster loading as compared to manual techniques with more uniform consistency of the catalyst loaded into the tubes. 
         [0049]    It has been found that such improved loading efficiency and performance is enabled by virtue of the ability to automatically and continuously fill the reformer tubes  200  in a predetermined controlled manner without interruption. To facilitate such continuous automated loading of the tubes, it will be understood that the hopper  511  should be maintained at least partially filled with catalyst by personnel or by an automatic filler (not shown). 
         [0050]    It will be further appreciated that since the continuous automated filling system  500  fills the tubes  200  with enhanced particle uniformity, there is no need to tap the tubes to prevent voids in the loaded catalyst typical of prior art procedures. As a result, the automated loading system  500  eliminates the need for vibrational elements and thus reduces the production of catalyst dust. In order to remove any small amounts of dust from the catalyst that may occur during transfer from the conveyor belt  514  into the intake duct  522 , a vacuum device  580  may be mounted in communication with a vacuum outlet  581  formed by a screened wall in the discharge shoot cover duct  524 . 
         [0051]    It will be appreciated that a new and useful system for reformer tube filling and processing has been described herein by way of example. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. 
         [0052]    Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.