Abstract:
A plurality of reactor tubes contained in a reactor vessel are filled with at least one catalyst by automatically measuring the catalyst by weight with equipment located at the site of the reactor vessel, and dispensing the measured catalyst into a plurality of reactor tubes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims the benefit of U.S. provisional application No. 60/392,750 filed Jun. 28, 2002. 
     
    
     
       STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not applicable.  
         REFERENCE TO A MICROFICHE APPENDIX  
         [0003]    Not applicable.  
         BACKGROUND OF THE INVENTION  
       DESCRIPTION OF THE RELATED ART  
         [0004]    Refer to the “Background of the Invention” section and other sections of U.S. Pat. No. 5,897,282, which is incorporated herein by reference, for general information concerning techniques and apparatus used to fill reactor tubes in catalyst reactor vessels with catalyst material(s).  
           [0005]    Various techniques have been used in the past to load catalyst into reactor tubes. One method filled tubes by volume. However, reactor tubes filled with equal volumes of catalyst may have a five percent to ten percent variance in weight (e.g. a thirty to forty gram variance) between the actual catalyst contained in respective tubes. Another prior method pre-measured catalyst by weight and individually sealed each measured amount into a resealable plastic bag at an off-reactor-site location. The plastic bags were then transported by drum to the worksite for loading into multi-compartment tube loaders or into reactor tubes. Once at the worksite, the drums were opened and bags removed for loading, e.g. ten bags at a time into tube loaders. This technique is very laborious as it may call for the pre-bagging of 100&#39;s of thousands of bags prior to arriving at the worksite followed by unbagging at the worksite. In another technique, individual quantities of catalyst were weighed by hand and then collected by hand for loading into a reactor tube. Last, in another technique which was learned about through secondhand conversations, it is believed BASF used a hopper to feed catalyst to a scaling belt conveyor, which led to a single tube, which was used to feed catalyst directly into a reactor tube. This device only filled one reactor tube at a time, and it was described as being slow.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    A plurality of reactor tubes contained in a reactor vessel are filled with at least one catalyst by automatically measuring the catalyst by weight with equipment located at the site of the reactor vessel, and dispensing the measured catalyst into a plurality of reactor tubes. The system improves efficiency, and saves time and wasted catalyst.  
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a schematic view of a reactor vessel worksite.  
         [0008]    [0008]FIG. 2 is an elevation view of a device for feeding and weighing catalyst.  
         [0009]    [0009]FIG. 3 is a top view of a five lane device for feeding and weighing catalyst. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0010]    Referring to FIG. 1, a reactor vessel worksite  10  is schematically shown. The reactor vessel  12  contains a plurality of reactor tubes  14 . The reactor tubes  14  extend vertically in the axial direction. One end of each reactor tube  14  is connected to a lower tube sheet  16  and the other end is connected to an upper tube sheet  18 . The reactor vessel  12  has an opening, entryway or removable head  20  to expose the upper tube sheet  18 . From the upper tube sheet  18 , each reactor tube  14  is designed to be filled with catalyst material(s)  22  for the purpose of carrying out the reaction.  
         [0011]    A bulk catalyst material(s)  24  which may or may not be pre-mixed is delivered to the worksite location  10  for the reactor vessel  12 . The bulk catalyst material(s)  24  may be delivered, for example, in a drum  26 . Next, the material(s) is/are transferred to an automated device for feeding and measuring the bulk catalyst material(s)  30  which may be mounted on a platform  21 . The automated device  30  can be made to fill multiple reactor tubes  14  at the same time or one reactor tube  14  at a time. The bulk catalyst material(s)  24  is/are measured by weight. After a desirable weight has been measured, the resulting quantity of the measured catalyst  28  is separately dispensed. Additional desirable weight quantities of the catalyst may be measured and separately dispensed. Weight measurements for each quantity may be performed simultaneously, sequentially, or part simultaneously and part sequentially. Each separate measured quantity of the catalyst  28  is dispensed into an individual reactor tube  14 .  
         [0012]    The process described in the preceding paragraph can be repeated for additional or different bulk catalyst material(s)  24  to be placed on top of the initial quantity of catalyst which has been loaded into a reactor tube  14 .  
         [0013]    Referring to FIG. 2, one embodiment of the automated (self-acting/operating/regulated/controlled) device for feeding and measuring the bulk catalyst material(s)  30  is shown. This embodiment generally includes a feed hopper  32  (optional), a feed trough  34  (optional), a main hopper  36 , a vibrating trough  40 , a vibrating motor  50 , a gate mechanism  60 , a catalyst dispenser  70 , a scale  80  and a computer  90 .  
         [0014]    A drum  26  or other device is used to transfer bulk catalyst material(s)  24   a  to the automated device for feeding and measuring the bulk catalyst material(s)  30 . The drum  26  may be mounted above the feed hopper  32 , the feed trough  34 , or the main hopper  36 . If the feed hopper  32  is incorporated into the system, it will feed catalyst materials onto the feed trough  34 . The feed trough  34  (such troughs are commercially available with a screening device in the trough), if incorporated, is used to screen broken pieces, dust, etc. and is used to feed (by vibration, gravity, etc.) catalyst materials to the main hopper  36 . The main hopper  36  is mounted above and feeds catalyst material(s) onto the vibrating trough  40  in a uniform manner (such hoppers  36  with uniform feed outlets are commercially available). The feeding of the catalyst material(s) onto the vibrating trough  40  in a uniform manner keeps unwanted weight off of the vibrating trough  40 , i.e., it prevents the build-up of a load within vibrating trough  40  of catalyst having excessive weight.  
         [0015]    The vibrating trough  40  may have a flat base  42  with two sidewalls  44  (one shown). One or more vibrating motors  50  (preferably variable speed) are connected to the lower side of the vibrating trough  40 . As a catalyst material  24  is fed onto the flat base  42 , the vibrating motor  50  shakes the vibrating trough  40 . This functions to feed/move the catalyst material (or materials)  24   b  along the vibrating trough  40  and divaricates the catalyst material on the flat base  42  as it moves along the trough. The vibrating trough  40  may have a slight decline in altitude from the entering end  45  to the exiting end  46 . The vibrating trough  40  may be replaced by some other device for moving the catalyst, such as, for example, a belt conveyor or other type of conveyor. The vibrating motor  50  includes control lines  52  which run to the computer  90 . The computer  90  determines when and how much to vibrate the vibrating trough  40  via the vibrating motor  50 .  
         [0016]    A gate mechanism  60  is mounted over the exiting end  46  of the vibrating trough  40 . The gate mechanism  60  includes a brush  62  or other device such as, for example, a catch or flapper (not shown). The gate mechanism  60  also includes control lines  64  which run to the computer  90  and to a power source. The computer  90  determines when the brush  62  is lifted (open) and when it is lowered (closed). When lifted, catalyst material  24   b  may be moved/vibrated off of the exiting end  46  of the vibrating trough  40 .  
         [0017]    A catalyst dispenser  70  is mounted below the exiting end  46  of the vibrating trough  40 . The catalyst dispenser  70  collects catalyst material  24   b  moved/vibrated off of the exiting end  46  of the vibrating trough  40 . Moreover, the catalyst dispenser  70  is used to weigh the catalyst material  24   b  which is collected. This may be accomplished by a scale  80  or load cell device connected to the catalyst dispenser  70 . Control lines  82  run from the scale  80  to the computer  90 . The computer  90  determines/measures the weight of the catalyst collected in the catalyst dispenser  70  and integrates this data with data for operating the vibrating motor  50  and for opening or closing the gate mechanism  60 . More than one quantity of catalyst can be weighed at the same time using multiple catalyst dispensers  70  each paired with a scale  80 .  
         [0018]    The catalyst dispenser  70  may be a dump bucket  72  which may or may not pivot. The catalyst dispenser  70  could also include, for example, a door mechanism  74 , etc. for dispensing the measured catalyst. Control lines  76  may be used to automate the door mechanism  74  via a pivot point  78 .  
         [0019]    The catalyst dispenser  70  is used for dispensing a measured quantity of catalyst  22  into a reactor tube  14 . This may be accomplished in a variety of ways, such as, for example, by dispensing each measured quantity of catalyst (one or more quantities of catalyst can be measured at the same time) into a funnel (or funnels)  84  which feeds such measured quantity into a transfer cassette (or cassettes)  86  having a plurality of catalyst loading compartments  88  (e.g. five or ten compartments) and used to hold catalyst by weight (similar to a transfer cassette commercially available from Bulk Material Equipment of Houston, Tex. which is used to hold catalyst by volume), by dispensing each measured quantity of catalyst into a storage bag, by dispensing each measured quantity of catalyst into a device (not shown) for transferring catalyst directly into reactor tubes  14 , etc. The transfer cassette(s)  86  are currently preferred and are then taken to, for example, multi-tube loaders (not shown) which load catalyst into a reactor, a funnel, etc.  
         [0020]    The computer  90  preferably includes a user interface such as a keypad  92  and display screen  94 . The keypad  92  may be used to enter operational parameters such as the target weight for each measured quantity of catalyst  24   b , the measurement rate or time allotted to measure each successive quantity of measured catalyst (e.g. ten to twenty measurements/compartments per minute), and/or allowable/desirable variance between each successive quantity of measured catalyst to be dispensed into a reactor tube  14 . Presently, it is recommended to have less than a three gram variation (preferably less than a one gram variation) between each measured quantity of like catalyst to be loaded into respective reactor tubes  14  (although the allowable variation may depend upon the job being performed as would be known to one of ordinary skill in the art, e.g., the weight and size of the individual catalyst particles depends upon the job being performed and would affect the allowable variation between each measured quantity). The display screen  94  may display by way of example, the production weight target, the actual weight of each successive measured quantity, the running speed, an average of weights, and/or the allowable variance between the target weight and each successive measured weight. Generally, the computer  90  may slow down the vibrating motor  50  and hence the rate of catalyst  24   b  falling into the catalyst dispenser  70  as the actual weight approaches the target weight. This slow down process may be dependent upon the allowable variance in weight. The accuracy of the measurements may also increase with each successive production of a measured quantity as the computer  90  can calibrate the system based upon prior readings of, for example, the actual weight versus the target weight while incorporating prior data on the vibration rate and amplitude, gate open time, accounting for drop distance and particles falling through the air after the signal is sent to close the gate, etc.  
         [0021]    Referring to FIG. 3, a five lane embodiment of the automated (self-acting/operating/regulated/controlled) device for feeding and measuring the bulk catalyst material(s)  30   a  is shown. The automated device for feeding and measuring the bulk catalyst material(s)  30   a  is normally set-up at the reactor vessel worksite  10  (depicted in FIG. 1). This embodiment generally includes a hopper trough  35 , five main hoppers  36   a - e,  five vibrating troughs  40   a - e,  five vibrating motors (hidden but similar to as shown in FIG. 2), five gate mechanisms  60   a - e,  five catalyst dispensers  70   a - e,  five scales  80   a - e  and a computer  90 . This embodiment may be used to measure and fill twenty to forty compartments  88  (FIG. 2) per minute, however such is somewhat dependent upon the size and weight characteristics of the catalyst being used. By way of example, this embodiment could be used to load a transfer cassette  86  having ten catalyst loading compartments  88  in series by loading every other compartment on a fist run, next shifting/sliding the transfer cassette  86  to align the five remaining empty compartments  88  under the device  30   a , and then loading the five remaining compartments  88 .  
         [0022]    Catalyst  24   a  is fed to each of the main hoppers  36   a - e  by the hopper trough  35 . and passes down through openings  37  onto the five lanes of vibrating troughs  40   a - e . The vibrating troughs may each be mounted on independent scales  80   a - e . Catalyst dispensers  70   a - e  are mounted below the exit and gate mechanisms  60   a - e  of the respective vibrating troughs  40   a - e . The catalyst dispensers  70   a - e  collect catalyst material  24   b  moved/vibrated off of the respective vibrating troughs  40   a - e . Moreover, the catalyst dispensers  70   a - e  are used to weigh the catalyst material  24   b  which is collected. This may be accomplished by respective scales  80   a - e  or load cell devices connected to the catalyst dispensers  70   a - e . Control lines  82  similar to as shown in FIG. 2 run from each of the scales  80   a - e  to the computer  90 . The computer  90  determines/measures the weight of the catalyst collected in each of the catalyst dispensers  70   a - e  (preferably independently) and integrates this data with data for operating the five separate vibrating motors  50  (similar to as shown in FIG. 2) and for opening or closing the gate mechanisms  60   a - e . As discussed above with respect to FIG. 2, each of the gate mechanisms  60   a - e  preferably has a brush tip  62  to enhance the closing of the gate mechanisms  60   a - e  against falling particles of the catalyst material  24   b . Preferably the computer  90  determines/measures the weight of the catalyst collected in each of the catalyst dispensers  70   a - e  independently and closes each respective gate mechanism  60   a - e  independently in response to the separate computations.  
         [0023]    Some data resulting from test runs of the automated devices for feeding and measuring the bulk catalyst material(s)  24   a  is reproduced below as an example of successive measurements by weight of catalyst which are achieved by the equipments:  
                                                                                           TARGET WT. 453   TARGET WT. 908           GRAMS (BRUSH)   GRAMS (METAL FLAPPER) 14.5           15 PER MINUTE &amp;   PER MINUTE 4           5 PER SECOND   PER SECOND                                        1   452.5   1   906.5           2   452   2   907.5           3   463   3   909.5           4   462   4   906.5           5   452   5   906           6   452.5   6   907           7   452   7   906.5           8   453.5   8   908           9   451   9   906.5           10   453.5   10   905           11   456.5   11   911           12   459.5   12   910.5           13   453.5   13   905.5           14   453   14   906.5           15   453.5   15   909           16   453.5   16   905.5           17   453.5   17   909           18   454.5   18   907           19   454.5   19   907           20   455.5   20   908           21   456   21   905           22   454   22   905           23   454   23   905.5           24   455.5   24   905.5           25   454.5   25   909           26   454           27   455                Total weight   12274.5   22678           Average weight   454.6   907.12           Low weight   452.5   905           High weight   463   911                      
 
         [0024]    Various changes may be made to the embodiment described without departing from the spirit of the invention claimed. For example, multiple automated devices for feeding and measuring the bulk catalyst material(s)  30  may be combined to form, for example, two simultaneous five lane loaders to make a ten lane loader; or a plurality of vibrating troughs  40  may be interconnected to form a multi-channel vibrating trough  40 . It is to be understood, however, that the loader is not limited to two, five or ten lanes (it could be more or less lanes). The transfer cassette  86  may also be automated to move with respect to the catalyst dispenser  70 . In this manner, a single scale  80  and catalyst dispenser  70  may perform automated filling of all compartments  88  in a transfer cassette  86 . The automated device for feeding and measuring the bulk catalyst material(s)  30  allows such to be accomplished quickly, i.e., at speeds greater than one compartment  88  (and hence one reactor tube  14 ) per minute, and up to speeds of ten to twenty compartments  88  (and hence reactor tubes  14 ) per minute or greater. This is a significant advantage over the prior art and is critical to making measurement by weight an improvement over the prior art. The system may also incorporate photo eyes for viewing catalyst to adjust the feed, and can control the feed rate of the hoppers  32 ,  36 . The system has the advantages over prior systems of being cleaner, more accurate in terms of dispensing the proper and uniform amounts of catalyst  22  into the reactor tubes  14 , operationally faster, and decreasing spillage.