U.S. patent application number 09/688065 was filed with the patent office on 2001-11-15 for catalytic reactor charging system and method for operation thereof.
Invention is credited to Comardo, Mathis P..
Application Number | 20010041117 09/688065 |
Document ID | / |
Family ID | 25535542 |
Filed Date | 2001-11-15 |
United States Patent
Application |
20010041117 |
Kind Code |
A1 |
Comardo, Mathis P. |
November 15, 2001 |
Catalytic reactor charging system and method for operation
thereof
Abstract
A catalyst loading system for utilizing catalyst from a bulk
supply located adjacent but not on the upper tube sheet of a
catalytic reactor and for mechanized measuring of multiple
identical quantities of catalyst and for mechanized loading of
catalyst pellets into the reaction tubes of the reactor to achieve
even drop rate, compaction and outage of the reaction tubes. From
the bulk supply, multi-compartment catalyst charging hoppers are
individually filled in rapid and accurately measured fashion by
mechanized filling equipment having a predetermined sequence of
operation that ensures accuracy of volumetric catalyst measurement.
The charging hoppers are used for delivery of measured volumes of
catalyst of a reactor tube loading mechanism which may take the
form of a mobile cart framework being selectively positionable
relative to the upper tube sheet and reaction tubes of a catalytic
reactor to be charged with catalyst pellets. A pair of electronic
vibrators are mounted to the cart framework and provide for support
and vibratory movement of a vibratory tray having a catalyst feed
hopper adapted to feed catalyst pellets to a plurality of generally
parallel catalyst transfer troughs along which catalyst pellets are
moved by vibration of the vibratory tray to a plurality of drop
tubes. A compartmented hopper is fixed to the vibratory tray and
controllably feeds catalyst pellets into respective catalyst
transfer troughs. A plurality of charging tubes are connected to
respective drop tubes by a plurality of elongate flexible tubes and
are maintained in fixed, spaced relation by a structural element so
as to define a charging manifold for simultaneous, timed delivery
of catalyst pellets into a plurality of reactor tubes. The charging
manifold has locator pins which are inserted into selected reactor
tubes for orienting the charging tubes of the charging manifold
with respect to a selected group of reaction tubes. A system is
also provided for raising and lowering the charging manifold for
efficiency of reactor tube charging operations. An electronic
control system is effective for controlling the vibrators to
achieve even drop rate from each of the catalyst transfer troughs
and to control the vibrators responsive to catalyst weight to
achieve even catalyst drop rate during an entire catalyst charging
cycle.
Inventors: |
Comardo, Mathis P.;
(Houston, TX) |
Correspondence
Address: |
Mayor Day Caldwell & Keeton LLP
700 Louisiana
Suite 1900
Houston
TX
77002
US
|
Family ID: |
25535542 |
Appl. No.: |
09/688065 |
Filed: |
March 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09688065 |
Mar 23, 2001 |
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08989863 |
Dec 12, 1997 |
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6132157 |
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Current U.S.
Class: |
414/160 ;
141/232; 222/608; 414/345; 414/586; 414/588; 414/804; 414/806 |
Current CPC
Class: |
B01J 8/0035 20130101;
B01J 8/003 20130101; B01J 2208/00752 20130101; B01J 8/002 20130101;
B01J 8/06 20130101 |
Class at
Publication: |
414/160 ;
414/586; 414/588; 414/804; 414/806; 414/345; 141/232; 222/608 |
International
Class: |
C10B 031/00 |
Claims
What is claimed is:
1. A catalyst loading cart for mechanized loading of catalyst
pellets into the reaction tubes of a catalytic reactor, comprising:
(a) a cart framework being selectively positionable relative to the
upper tube sheet of a catalytic reactor to be charged with catalyst
pellets; (b) at least one electronic vibrator being fixed to said
cart framework; (c) a vibratory tray being connected for vibration
thereof by said electronic vibrator and having a plurality of
generally parallel catalyst transfer troughs through which catalyst
pellets are moved by vibration of said vibratory tray and a
plurality of drop tubes through which catalyst pellets drop from
said catalyst transfer troughs of said vibratory tray; (d) a
loading cart hopper being fixed to said vibratory tray and having a
plurality of catalyst compartments each being disposed to feed
catalyst pellets into respective catalyst transfer troughs; (e) a
catalyst charging manifold having a plurality of charging tubes
each being disposed in immovable spaced relation and being
receivable within the reaction tubes of the reactor, (f) a
plurality of elongate flexible tubes having upper and lower ends
and having the upper ends thereof connected to respective drop
tubes and the lower ends thereof connected to respective charging
tubes; (g) charging manifold locator elements projecting from said
charging manifold and being receivable within selected reactor
tubes for location of said charging tubes within other selected
reactor tubes for charging thereof with catalyst pellets; and (h)
electronic control means being in electrically controllable
connection with said at least one electronic vibrator and being
adjustable to achieve vibrator control for substantially identical
discharge rate of catalyst pellets from each of said catalyst
transfer troughs.
2. The catalyst loading cart of claim 1, wherein said at least one
electronic vibrator comprising: (a) a pair of electronic vibrators
each having electronic operational circuits and having vibratory
connection with respective side portions of said vibratory tray;
(b) a pair of adjustable electronic trimmer circuits being
electrically connected to respective electronic operational
circuits of respective electronic vibrators for adjusting the
amplitude of vibration thereof to achieve substantially identical
rate of discharge of catalyst pellets from each catalyst transfer
trough of said vibratory tray; and (c) a master adjustable
electronic vibrator control circuit being electronically connected
to both of said adjustable electronic trimmer circuits and being
adjustable to vary the rate of catalyst discharge from said
vibratory tray.
3. The catalyst loading cart of claim 1, wherein: (a) weight
responsive signal means generating electronic control signals
responsive at least in part to the weight of catalyst pellets
within said loading cart hopper; and (b) control circuitry
receiving said weight responsive signals and controlling the
amplitude of vibration of said electronic vibrator responsive to
said weight responsive signals to achieve a selected rate of
catalyst pellet discharge from said vibratory tray regardless of
the weight of catalyst pellets within said loading cart hopper.
4. The catalyst loading cart of claim 3, wherein said weight
responsive signal means comprising: (a) an accelerometer being
fixed to said vibratory tray for detecting the amplitude of
vibratory motion thereof and providing an amplitude related
electronic signal output responsive thereto: (b) a signal
conditioning circuit receiving and conditioning said amplitude
related electronic signal output and providing conditioned weight
related output signals; and (c) said control circuitry receiving
said conditioned weight related output signals and controlling
operation of Said vibrator to maintain substantially constant
vibratory amplitude of said vibratory tray as the weight of
catalyst pellets within said loading cart hopper is depleted during
a catalyst loading cycle.
5. The catalyst loading cart of claim 1, wherein: (a) wheel
retraction means being moveably connected to said cart framework:
and (b) wheels being connected to said wheel retraction means and
being selectively positionable by said wheel retraction means at an
extended position for mobile support of said catalyst loading cart
by said wheels and a retracted position for support of said
catalyst loading cart by said cart framework.
6. The catalyst loading cart of claim 5, wherein: (a) a pair of
wheel positioning elements each being pivotally connected to said
cart framework; (b) a pair of wheels being mounted to each of said
wheel positioning elements; and (c) an actuator assembly being
supported by said cart framework and being operative to impart
pivoting movement to said wheel positioning plates for selectively
positioning said wheels at said extended and retracted positions
thereof.
7. The catalyst loading cart of claim 1, wherein: (a) a vent hood
being pivotally mounted to said vibratory tray for location above
said plurality of catalyst transfer troughs; and (b) a source of
vacuum being in communication with said vent hood for removing dust
released from catalyst pellets during transfer thereof along the
length of said catalyst transfer troughs.
8. The catalyst loading cart of claim 1, wherein: (a) said catalyst
transfer troughs each having perforate bottom wall sections through
which catalyst tailings and dust descend for separation thereof
from the catalyst pellets being transferred along said catalyst
transfer troughs by vibratory action of said vibratory tray; and
(b) a catch pan being located immediately below said catalyst
transfer troughs and in position for catching any catalyst tailings
and dust that descend through said perforate bottom wall
sections.
9. The catalyst loading cart of claim 8, wherein: a source of
vacuum being in communication with said catch pan for removing
catalyst tailings and dust released from catalyst pellets and
descending through said perforate bottom wall sections during
transfer of catalyst pellets along the length of said catalyst
transfer troughs by said vibratory action of said vibratory
tray.
10. The catalyst loading cart of claim 1, wherein: said catalyst
charging manifold being vertically movable relative to said
vibratory tray to permit efficiency of selective positioning of
said charging tubes in charging relation with selected reactor
tubes.
11. The catalyst loading cart of claim 1, wherein: (a) a plurality
of adjustment tubes being disposed in telescoping vertically
adjustable relation with respective drop tubes; (b) a structural
member securing said adjustment tubes in fixed relation with one
another; and (c) means for moving said structural member and thus
said adjustment tubes upwardly and downwardly relative to said drop
tubes; and (d) said flexible tubes of said charging manifold being
connected to respective adjustment tubes and, upon vertical
movement thereof by said adjustment tubes, causing vertical
movement of said charging manifold.
12. The catalyst loading cart of claim 1, wherein: (a) said loading
cart hopper defining an upwardly facing opening and having a
movable closure for said upwardly facing opening; (b) a portable
charging hopper having the same number of internal catalyst
compartments as said loading cart hopper and having an open bottom
section adapted to be received in charging assembly with said
upwardly facing opening of said loading cart hopper; and (c) a
slide gate being positionable to close said open bottom of said
portable charging hopper for securing catalyst pellets with said
internal catalyst compartments of said portable charging hopper and
being selectively movable to an open position for dumping catalyst
pellets into respective catalyst compartments of said loading cart
hopper.
13. The catalyst loading cart of claim 12, wherein: (a) said
portable charging hopper defining an upwardly facing opening; and
(b) a closure being in movable relation with said portable charging
hopper and being positionable for closing said upwardly facing
opening thereof.
14. The catalyst loading cart of claim 12, wherein: (a) said
portable charging hopper defining a gate opening and gate track;
(b) said slide gate being movable through said gate opening and
along said gate track during opening and closing movement
thereof.
15. A method for charging the multiple reaction tubes of a
catalytic reactor having a shell and an upper tube sheet to which
the upper ends of a multiplicity of reaction tubes are connected
and to charge the reaction tubes with measured charges of catalyst
pellets, comprising: (a) locating on the upper tube sheet and
within the bounds of the reactor shell of the catalytic reactor a
catalyst loading cart having a multiple compartment feed hopper and
a multi trough vibratory tray operated by a pair of electrically
energized vibrators and having a plurality of drop tubes for
simultaneous dropping of catalyst pellets into a plurality of the
reaction tubes of the reactor; (b) controllably vibrating the
vibratory tray of the catalyst loading cart for controlled transfer
of catalyst pellets along said multiple troughs for dropping
thereof through said drop tubes and into the reaction tubes at a
predetermined drop rate; (c) locating a catalyst charging hopper at
a catalyst source outside the bounds of said upper tube sheet, said
catalyst charging hopper having the same number of charging
compartments as the number of compartments of said feed hopper; (d)
filling all of said measuring compartments of said charging hopper
with catalyst pellets; (e) closing said charging hopper; (f)
manually transporting the filled charging hopper to said catalyst
loading cart and placing said charging hopper in charging assembly
with said feed hopper, with the compartments of said charging
hopper in charging registry with the compartments of the feed
hopper; (g) simultaneously releasing the catalyst of said charging
compartments into the compartments of said feed hopper; and (h)
returning said charging hopper to said catalyst supply site for
refilling thereof with catalyst.
16. The method of claim 15, comprising: (a) providing electronic
signals responsive to the weight of catalyst within said feed
hopper; and (b) adjusting the electrical supply to said vibrators
responsive to said weight related electronic signals to maintain
the amplitude of vibrator movement substantially constant at all
conditions of catalyst weight within said feed hopper.
17. The method of claim 15, comprising: (a) measuring the amplitude
of movement of said vibratory tray with said feed hopper full of
catalyst and providing electronic signals responsive to the
measured amplitude; (b) adjusting the electrical supply to said
vibrators responsive to weight responsive changes to said measured
amplitude to maintain the amplitude of movement of said vibratory
tray substantially constant at all conditions of catalyst weight
within said feed hopper.
18. A method for filling a multi-compartment catalyst charging
hopper with a measured quantity of catalyst with each measuring
compartment thereof containing substantially identical volumes of
catalyst, comprising: (a) providing a bulk catalyst hopper having a
discharge outlet and a discharge gate movable to an open position
to permit discharge of catalyst into said charging hopper and a
closed position blocking discharge of catalyst from said discharge
outlet; (b) positioning a charging hopper at a fill position to
receive discharge of catalyst from the discharge outlet of the bulk
catalyst hopper; (c) opening said gate for a sufficient period of
time to overfill each of the measuring compartments of said
charging hopper, (d) closing said gate; (e) removing excess
catalyst from each of the measuring compartments of the charging
hopper; and (f) moving the charging hopper from said fill
position.
19. The method of claim 18, wherein said step of positioning
comprises: (a) placing an empty charging hopper on a movable
trolley of said bulk hopper, with the movable trolley located at a
start position; (b) moving the movable trolley to a loading
position where the catalyst charging hopper is located to receive
catalyst from the bulk hopper discharge outlet; and said charging
hopper has been overfilled, returning the movable trolley to the
start position.
20. The method of claim 18, comprising: vibrating the charging
hopper during filling thereof to settle catalyst in the multiple
measuring compartments of the charging hopper and to ensure
complete filling of each of the multiple measuring compartments
thereof.
21. The method of claim 18, wherein said moving step comprising:
(a) moving a filled charging hopper from said fill position; and
(b) during said moving of the filled charging hopper applying a
wiper to excess catalyst present on the charging hopper to wipe
away the excess, thus leaving the charging hopper with accurately
measured volumes of catalyst in each of the multiple measuring
compartments thereof.
22. The method of claim 21, wherein the wiper being a brush, the
method comprising: brushing away excess catalyst.
23. The method of claim 21, wherein the wiper being a movable
brush, the method comprising: moving the movable brush against the
excess catalyst for brushing away excess catalyst.
24. The method of claim 21, wherein the wiper being a rotatable
brush, the method comprising: rotating the rotatable brush against
the excess catalyst during return of the trolley from the fill
position to the start position for brushing away excess
catalyst.
25. The method of claim 18, wherein a catch receptacle is located
beneath said discharge outlet of said bulk hopper, said method
comprising: (a) during said moving step directing removed excess
catalyst into the catch receptacle; and (b) periodically returning
excess catalyst from the catch receptacle to the bulk hopper.
26. The method of claim 18, wherein the bulk hopper mechanism
defining a substantially closed filling chamber, said method
comprising: removing air borne catalyst dust from the substantially
closed filling chamber.
27. A method for filling a multi-compartment catalyst charging
hopper with a measured quantity of catalyst with each measuring
compartment thereof containing substantially identical volumes of
catalyst, comprising: (a) providing a bulk catalyst hopper having a
discharge outlet and a discharge gate movable to an open position
to permit discharge of catalyst into said charging hopper and a
closed position blocking discharge of catalyst from said discharge
outlet; (b) positioning a charging hopper on a movable trolley at a
start position and moving the trolley and charging hopper to fill
position to receive discharge of catalyst from the discharge outlet
of the bulk catalyst hopper; (c) opening said discharge gate for a
sufficient period of time to overfill each of the measuring
compartments of said charging hopper; (d) closing said discharge
gate; (e) moving said movable trolley with the overfilled charging
hopper thereon from said fill position to said start position; and
(f) during said moving causing contact of excess catalyst of the
overfilled charging hopper with a brush thus brushing excess
catalyst from each of the measuring compartments of the charging
hopper.
28. Apparatus for filling a multiple compartment catalyst charging
hopper such that each of the multiple measuring compartments
thereof contain substantially identical volumes of catalyst,
comprising: (a) a bulk hopper having a discharge outlet; (b) a
discharge gate being movable to an open position permitting
discharge of catalyst from said discharge outlet and being movable
to a closed position blocking the discharge of catalyst from said
discharge outlet; (c) a trolley adapted for support of a charging
hopper and being movable from a start position where the charging
hopper is manually accessible to a fill position where the charging
hopper is positioned for receiving catalyst from said discharge
outlet; (d) means for moving said trolley from said start position
to said fill position and for returning said trolley from said fill
position to said start position; and (e) means for removing excess
catalyst from the charging hopper during said returning of said
trolley from said fill position to said start position.
29. The apparatus of claim 28, wherein; (a) a track extending from
said start position to said fill position; (b) said trolley having
wheels having rolling engagement with said track; and (c) said
means for moving said trolley being a linear motor mounted to said
apparatus and having driving connection with said trolley.
30. The apparatus of claim 28, wherein said means for removing
excess catalyst from said catalyst charging hopper comprising; a
brush disposed for engagement with excess catalyst on said catalyst
charging hopper during movement of said trolley from said fill
position to said start position.
31. The apparatus of claim 30, wherein: a vibrator being mounted to
said trolley and, when energized, causing vibration of said trolley
for settling catalyst within each of the multiple measuring
compartments of the catalyst charging hopper.
32. The apparatus of claim 28, comprising: (a) a base structure;
and (b) means adjustably supporting said bulk catalyst hopper on
said base structure and being adapted for controlled elevational
positioning of said bulk catalyst hopper relative to said base
structure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the controlled filling
of the catalyst tubes of catalytic reactors with catalyst materials
when the reactors are placed into service or when they have been
cleaned of spent catalyst materials in preparation for further use
in processes requiring catalytic reaction of flowing products of
the process. More particularly, the present invention concerns a
mechanized catalytic reactor charging system including a loading
cart that is used by reactor servicing personnel and which is
effective for efficient and controlled and simultaneous charging of
a plurality of the reaction tubes of a catalytic reactor so that
each of the plurality of reaction tubes will contain a precise
measured quantity of the catalyst arranged in one or more layers
and having a predetermined degree of compaction. Even further, the
present invention concerns a mechanized catalyst loading cart
having the capability for automatically adjusting the amplitude of
vibratory movement of a dispensing control tray thereof with
respect to the weight of catalyst material contained therein for
dispensing, so as to ensure the consistent measured and timed
dispensing of the catalyst material during a complete dispensing
cycle of the loading cart. This invention also concerns a method
and apparatus for the mechanized filling of catalyst charging
hoppers at a location remote from the tube sheet of the reactor and
for efficiently and safely charging the catalyst loading cart with
catalyst material from the catalyst charging hoppers.
[0003] 2. Description of the Prior Art
[0004] Although, for the purpose of discussing the preferred
embodiment of the invention disclosed herein, the present invention
is discussed particularly as it relates to the dispensing of
measured quantities of catalyst material into the reaction tubes of
catalytic reactors, it should be borne in mind that the invention
may be employed for the dispensing of measured quantities of other
materials for other purposes. Thus the scope of the present
invention is not intended to be limited by the specific discussion
of the preferred embodiment, but rather the preferred embodiment of
this invention is intended only as a representative example that
comes within the spirit and scope of the invention.
[0005] In a chemical plant the desired chemical is generally
manufactured with the use of a tube and shell type catalytic
reactor. The typical catalytic reactor is a cylindrical structure
approximately 15' in diameter and can be 100' or so in height (all
catalytic reactors are custom designed and built for a particular
chemical process and thus can have a wide range of diameters and
heights). The reactor is typically in the form of a cylindrical
shell having domed and flanged top and bottom ends that are
unbolted and removed to permit servicing of the reactor. A
multiplicity of reaction tubes are typically located vertically in
the reactor and have upper and lower ends that are welded to upper
and lower tube sheets that extend transversely of the reactor shell
and are located adjacent the end flanges of the reactor shell. The
reaction tubes are typically in the order of 1" in diameter and are
welded to the tube sheets in a geometric pattern. A worker standing
on the upper tube sheet will visualize a flat sheet having a
multiplicity of holes arranged in a geometric pattern and being
about 1/2" apart, with each hole having a weld bead about it for
connection of the upper tube end to the upper tube sheet.
[0006] One or more types of catalyst material is loaded into each
of the reaction tubes and is provided in the form of small spheres
or cylinders in the range of from {fraction (1/16)}" to 1/2" in
diameter. The catalyst pellets are typically composed of ceramic or
alumina material that is coated with a reactive agent for the
process that is intended. Upon activation in the presence of a
fluid flowing through the reaction tubes the catalyst reacts with
the flowing fluid to give off a derivative product. Generally, the
catalyst is loaded into the reaction tubes (some up to 20,000
tubes) in zones or layers. That is to say, if the reaction tube is
60' in height, catalyst "A" would comprise a 20' zone, catalyst "B"
would comprise a second 20' zone and catalyst "C" would comprise a
third 20' zone. The loading rate of the catalyst into these tubes
determines the compaction of the catalyst within the tubes. This is
referred to as "drop time". The space remaining within the tubes
which is above the upper end of the catalyst is referred to as
"tube outage". Ideally, if all (20,000) tubes have the same "drop
time" during charging or loading thereof, the tube outage (the
balance of unfilled tube) will be uniform. When the reactor tubes
are all charged uniformly it will yield the best reactor
performance, i.e., the best quality and quantity of resulting
chemical product.
[0007] At the present time most catalyst loading or charging
operations are conducted by completely manual activities, with
workers using a funnel to direct catalyst pellets into a selected
reaction tube as the catalyst is poured by hand from small
premeasured bags. It is well known that each worker of a charging
crew will typically pour catalyst pellets at a slightly different
rate so that the result can often be poor drop time uniformity thus
resulting in uneven tube outages. In some cases the catalyst
pellets will bridge within some of the reaction tubes due to
non-uniform drop time and catalyst compaction, thus resulting in
voids that cause "hot spots" and uneven fluid pressures and
temperatures within the various tubes of the reactor. The resulting
chemical product from reactors that have not been uniformly charged
with catalyst is often less than optimum quality.
[0008] Various attempts have been made to provide a mechanized
catalyst loader and method of filling catalytic reactor tubes with
pellets of catalyst materials. One example is presented by U.S.
Pat. No. 3,223,490 of Sacken, et al wherein a plate is drilled to
the same pattern as the holes of the reactor tubes and
corresponding fill tubes are dependent from the plate so as to be
loosely received within respective reactor tubes. The catalyst
material is then dropped through the fill tubes into the reactor
tubes until the level of the catalyst in each of the reactor tubes
reaches the level of the fill tubes. Thereafter, the plate and its
fill tubes are lifted so that the remaining catalyst pellets in
each of the fill tubes will be deposited into the reaction tubes.
This type of controlled filling achieves virtually the same
catalyst bed height in each of the reactor tubes but it does not
take into consideration the problem of catalyst pellet bridging and
compaction within the respective reaction tubes. Thus, though the
upper end of the catalyst beds in the tubes can be virtually the
same, voids within part of the reaction tubes which occurs by
uncontrolled drop rate will result in uneven catalyst materials in
the catalyst beds. Further, this method does not provide for
consistent drop rate of the catalyst so that uneven tube outage and
non-uniform compaction can be the result. This could result in the
development of hot spots within the reactor which could be
detrimental to reactor operation. Also, since virtally every
reactor is "custom designed" so its height, diameter and number of
catalyst reactor tubes can vary, clearly the catalyst loader shown
in this patent must also be "custom designed", for the reactor hole
pattern and dimension of the reactor. Thus, a catalyst loader of
this nature would need to be dedicated to this particular reactor
so that a catalyst loader would be needed for each reactor. It is
desirable therefore to provide for catalyst loading operations by
means of mechanized catalyst loading which is readily adjustable to
the hole pattern and tube dimension of various types of catalytic
reactors.
[0009] A catalyst loading cart mechanism is presented by U.S. Pat.
No. 4,402,643 of Lytton, et al which has a plurality of catalyst
storage hoppers each feeding a respective slot of a vibratory tray,
with the catalyst pellets dropping from the tray into respective
flexible conduits that are engaged within the upper openings of a
plurality of reaction tubes. This apparatus has proved ineffective
because the vibratory activity of the tray does not ensure
precision control of the drop rate of the catalyst pellets from
each of the feed grooves of the tray. Use of this apparatus has
been discontinued as ineffective for simultaneous loading of
multiple catalytic reactor tubes.
[0010] Another prior art reactor tube loading device is disclosed
by U.S. Pate. No. 4,701,101 of Sapoff, wherein a catalyst loading
funnel is provided having a plurality of generally triangular
storage chambers which feed catalyst fill tubes that are inserted
into the openings of a plurality of reaction tubes. The funnel
mechanism may be supported by a wheeled cart and provided with
flexible tubes having tubular spouts at the lower ends thereof
which are received within the openings of a plurality of reaction
tubes. The drop rate of the catalyst material is intended to be
adjustable by adjusting the speed of rotation of metering rods or
by raising and lowering metering rods in each funnel module to
increase or decrease the speed of catalyst drop.
[0011] Although catalytic reactors for chemical processes may take
various forms, for purposes of the present invention the reactors
of particular concern are fixed bed type catalytic reactors having
an external housing or shell of considerable height within which is
mounted a multiplicity of reaction tubes, the tubes being supported
at the upper and lower ends thereof by means of tube sheets. The
reaction tubes may also be provided with intermediate support if
appropriate for the structural integrity of the reactor mechanism.
The catalytic reactors typically utilized in the petroleum and
petrochemical industries typically employ reactor tubes having an
internal diameter in the order of one inch and a length in the
order of from 60' to 100' or more. Depending upon the character of
the reaction to occur, the reactor tubes may be filled to a
predetermined level with pellets of catalyst material so that the
outage (the space above each tube bed of catalyst) will be
substantially the same. In many cases, each reactor tube will
contain two or more catalyst materials each arranged to a
predetermined fill level. For efficient operation of catalytic
reactors, each of the reaction tubes should be loaded with catalyst
pellets in precisely the same way so as to obtain consistency of
catalyst arrangement and compaction within each of the reaction
tubes. Typically, catalytic reactors are loaded or charged by means
of a highly labor intensive manual loading operation. In this case,
workers are present at the upper tube plate of the reactor, where
the openings of the multiple reaction tubes are exposed. These
workers utilize funnels having lower discharge tubes that are
inserted into the tube opening of a reaction tube to be filled.
These tube filling personnel are typically trained to deposit
reactor pellets into the funnel and thus, into the reaction tube in
accordance with a predetermined quantity input which is referred to
as "drop time" or "drop rate". If the quantity input of the
catalyst is exceeded, it is possible that the catalyst pellets can
bridge within the tubes, thereby developing voids in the catalyst
beds of some of the tubes and thus resulting in uneven outage at
the upper ends of some of the tubes. The character of catalyst
input to the various tubes of a reactor is also determined by the
character of the catalyst being loaded. Catalyst materials are
provided in spherical pellets of various size and are also provided
in cylindrical pellets of varying size. The respective pellets
whether cylindrical or spherical must be dropped into the tubes in
accordance with a particular timing sequence "drop time" so that
the resulting catalyst bed in each of the tubes will be virtually
the same and the outage at the tops of the tubes will also be
virtually the same.
[0012] The upper and lower ends of a cylindrical reactor shell are
typically closed by means of domed closures that are secured by
bolts to upper and lower connector flanges of the reactor shell.
For catalyst loading, the upper domed closure is typically unbolted
from the catalyst shell, is lifted therefrom by means of a crane
and is typically lowered to the ground until the tube filling
procedure has been completed. To facilitate loading of the catalyst
materials into the multiple reaction tubes of a catalytic reactor,
a temporary "working compartment" of sufficient height for a worker
to stand on the upper tube sheet of a reactor is assembled to the
upper end of the reactor shell. This enclosure is typically
air-conditioned for the comfort of workers and is provided with a
dust removal system to ensure as much as possible that catalyst
dust, that is typically liberated into the atmosphere during the
charging operation, is continuously removed from the working
enclosure. Further, the workers engaged in the loading operation
typically wear sealed outer garments that prevent the catalyst dust
from coming into contact with the worker's skin and also wear
ventilation equipment to ensure the that the catalyst dust is not
breathed by the workers.
[0013] Obviously, manual loading of catalyst materials by means of
funnels as is currently done, is subject to many disadvantages. For
example, the labor requirements for a manual catalyst loading
operation add significant cost to the reactor and thus add to the
cost of the resulting product. It is therefore desirable to provide
for mechanized catalyst loading operations that significantly
minimize labor costs. Since hand loading of catalyst materials is
subject to wide variation of drop time, catalyst compaction, etc.,
depending upon the catalyst materials being used and the workers
accomplishing the loading operation, it is desirable to provide a
mechanized catalyst loading operation to enable precision loading
of each of the catalyst tubes of the reactor so that the resulting
catalyst bed in each of the tubes is virtually the same and the
outage between the catalyst bed and the tube sheets of the reactor
is also virtually the same. Tests which have been conducted
indicate clearly that mechanized catalyst loading is much superior
in comparison with hand loading of catalyst materials because the
drop rate of the catalyst materials can be efficiently controlled
so that the drop rate is the same with each of the catalyst
materials within each of the reaction tubes.
[0014] From the inventor's studies concerning loading operations
for catalytic reactors, virtually any phase of the catalyst
handling and reactor loading operations where manual operations are
used, the results of such operations can be improved by
mechanization, thus achieving repeatability and better
productivity. Thus, according to the present invention is desirable
to provide a catalyst handling, measuring and catalytic reactor
charging system that as much as possible takes advantage of
mechaniztion and minimizes the manual-aspects of catalytic reactor
servicing operations.
SUMMARY OF THE INVENTION
[0015] It is a principal feature of the present invention to
provide a novel mechanized catalyst handling, measuring and reactor
tube charging system that permits efficiency and accuracy of
catalyst measuring from a bulk catalyst supply located remote from
the upper tube sheet of a catalytic reactor being charged and
controlled dispensing of catalyst pellets into multiple reactor
tubes in such manner that drop time, catalyst compaction and tube
outage are consistent in all of the reactor tubes.
[0016] It is also a feature of the present invention to provide a
novelized catalyst loading cart having the capability for use in
the loading of catalyst material in catalytic reactors in virtually
any size, design or tube pattern.
[0017] It is another feature of this invention to provide a novel
catalyst loading cart having the capability of efficiently feeding
catalyst pellets into the upper ends of the catalyst reaction tubes
in accordance with a precision predetermined drop rate for insuring
that the catalyst beds are virtually the same in each catalytic
reactor tube and that no catalyst voids are present within any of
the reaction tubes.
[0018] It is a even further feature of the present invention to
provide a novel catalyst loading cart for catalytic reactors having
multiple catalyst charging tubes that are provided with lower
charging fittings, with the fittings being supported by a charging
manifold structure and arranged for simultaneous insertion of the
open upper ends of a plurality of reaction tubes so that multiple
reaction tubes can be simultaneously charged with catalyst.
[0019] It is an even further feature of the this invention to
provide a novel catalyst loading cart having a wheeled cart
framework which can be raised relative to caster wheels which
permit the cart to be movable on the tube sheet of the reactor and
which can be lowered relative to the caster wheels to provide for
stable support of the cart on the tube sheet of the reactor or on a
cover panel that might be provided to cover appropriate portions of
the tube sheet.
[0020] It is another feature of this invention to provide a novel
catalyst loading cart mechanism having a mobile cart framework for
support of a vibratory catalyst transfer tray, and wherein a
charging manifold is provided that is vertically moveable relative
to the cart framework to provide for controlled positioning of
catalyst discharge openings of the manifold in charging registry
with a selected group of the reaction tubes for simultaneous
charging thereof with catalyst material.
[0021] It is an even further feature of this invention to provide a
novel catalyst loading cart having a vibratory catalyst transfer
tray with a plurality of catalyst transfer troughs or grooves
through which catalyst material is conducted to a plurality of drop
tubes and wherein a pair of electronically energized vibratory for
the vibratory tray are each individually amplitude adjustable
responsive to ensure uniformity of catalyst discharge from each of
the slots of the tray so that the drop rate of catalyst into each
of the plurality of reaction tubes being charged will be
uniform.
[0022] It is another feature of the present invention to provide a
mechanized catalyst loading cart having an adjustable feed hopper
with multiple catalyst chambers, one for each catalyst transfer
trough of a vibratory tray and wherein the amplitude of vibration
of the tray is automatically adjustable responsive to the weight of
catalyst within the hopper so that the rate of delivery of catalyst
material to the drop tubes of the tray during a charging cycle will
not change as the catalyst material is dispensed and the weight of
the catalyst within the hopper decreases.
[0023] It is also a feature of the present invention to provide a
mechanized catalyst loading cart having a multi-compartment
catalyst hopper from which catalyst is fed at a uniform drop rate
from each of the hopper compartments and further having at least
one portable charging hopper which also has multiple compartments
of identical size and which is filled with catalyst at a location
remote from the upper tube sheet of a reactor and, after being
closed to secure the catalyst contained therein, is carried to a
catalyst loading cart, positioned on the upper tube sheet of the
reactor and positioned in charging assembly with the hopper of the
cart and is manipulated to discharge the measured contents of the
compartments thereof into the respective compartments of the
loading cart hopper without any risk of spillage.
[0024] Among the several features of the present invention is
contemplated the provision of mechanized apparatus for efficiently,
accurately and quickly filling all of the multiple compartments of
a portable charging hopper with substantially identical quantities
of catalyst, so that the hopper of the catalyst loading cart can
itself be charged with accurately measured quantities of catalyst
in the respective charging chambers of the apparatus and can do so
quickly and efficiently and with minimal labor costs.
[0025] Briefly, the various objects and features of the present
invention are realized through the provision of a mechanized
catalyst loading cart of mobile nature which is used at the upper
tube sheet of a catalytic reactor for the purpose of charging the
multiple reaction tubes of the reactor with one or more types of
catalyst pellets. In each embodiment of the present invention, the
catalyst loading cart includes a vibratory tray having a plurality
of tray troughs or grooves that conduct catalyst pellets from the
tray into a plurality of flexible catalyst delivery tubes that
direct the falling catalyst pellets into respective reaction tubes
of the reactor. One delivery tube will be provided for each of the
catalyst troughs or grooves of the tray. At their lower ends, the
delivery tubes are fixed to a charging manifold having a plurality
of depending charging tubes of sufficiently small dimension as to
enter within the small diameter openings of the reaction tubes. The
charging tubes are arranged according to the pattern and spacing of
the reaction tubes to be charged. The charging manifold is provided
with a pair of manifold locators that enter tube openings at the
tube sheet and provide for orientation of the manifold and the
plurality catalyst charging tubes so that the charging tubes will
enter a selected group of reaction tubes for the purpose of
catalyst charging. The vibratory tray is provided with a hopper
having a plurality of catalyst compartments, one for each of the
catalyst transfer troughs or slots of the tray. Catalyst material
is metered from each of the catalyst compartments by means of an
adjustable weir having a plurality of weir gates thereon which
extend into respective transfer troughs and control delivery of
catalyst pellets from the respective hopper compartments to the
transfer troughs.
[0026] The vibratory tray is vibrated by means of two or more
electrically energized vibrators that are each amplitude adjustable
by means of electronic trimmer circuits. By adjusting individual
potentiometers of the trimmer circuits, a user can achieve
substantially even delivery of catalyst pellets from each of the
plurality of catalyst troughs of the vibratory tray. This feature
overcomes a disadvantage of the prior art, because a single
vibrator cannot ordinarily be adjusted to provide even dispensing
of catalyst pellets from each of the troughs of a vibratory
tray.
[0027] For optimum delivery of catalyst pellets into a plurality of
reaction tubes, a predetermined catalyst drop rate is established
which is sufficiently high to achieve efficient production and is
not high enough to result in bridging or improper compaction of
catalyst pellets within respective reaction tubes. It has been
determined, however that the feed rate of catalyst pellets from a
vibratory tray having a multiple chamber hopper associated
therewith will typically change during a catalyst charging cycle as
the result of decreasing catalyst weight. The amplitude of
vibration of a vibratory tray will typically change from the time
dispensing begins, when the hopper compartments are full of
catalyst pellets, to the time when the total charge of catalyst has
been depleted. The vibratory tray will be vibrated at a desired
amplitude when catalyst dispensing begins, but as the weight of the
catalyst decreases within the hopper compartments, the vibratory
amplitude of the tray will be increased simply because the weight
of the dispensed catalyst is not present and thus the mass of the
vibratory tray and its contents becomes less as the catalyst
dispensing cycle progresses. It is desirable, therefore to provide
for vibration of a catalyst transfer tray which is minimally
influenced by changes in the weight or mass of the transfer tray
and its contents. This feature is provided by an electronically
controlled system which automatically adjusts the electrical power
to the vibrators to compensate for reduced weight so that the rate
of catalyst delivery from the hopper through the transfer tray will
remain substantially the same as the catalyst pellet charge is
depleted during dispensing. A solution of this problem is achieved
by the provision of an accelerometer regulated amplitude control
system which senses the amplitude of vibration of the vibratory
tray and provides electronic signals responsive thereto. These
weight related electronic signals are then conditioned and fed to
vibrator control circuitry to automatically trim the electrical
power supply to the vibrators as needed to maintain a substantially
constant rate of tray vibration and thus maintain an substantially
constant rate of catalyst pellet drop from the catalyst transfer
troughs during a complete catalyst charging cycle. Thus, the
delivery of catalyst pellets to the reactor tubes is not
significantly altered by the decreasing weight of catalyst during a
catalyst charging sequence.
[0028] Since catalyst materials have been determined to have
carcinogenic characteristics requiring workers during catalyst
loading operations to wear sealed clothing and ventilation systems,
the vibratory tray is provided with a vacuum hood and a vacuum tray
so that any catalyst dust or tailings liberated from the catalyst
pellets will be removed by the vacuum for disposal. Thus the
loading cart apparatus assists in maintaining the working
environment for the catalyst loading operation substantially free
of catalyst dust and tailings.
[0029] To ensure against inadvertent spillage of catalyst pellets
onto the upper tube sheet and thus into the reaction tubes during
charging of the loading cart hopper with catalyst and to further
ensure simple and efficient charging of each of the loading cart
hopper compartments with measured quantities of catalyst a portable
charging hopper is provided. This charging hopper is provided with
the same number of measuring compartments as the compartments of
the loading cart hopper and is provided with a movable bottom wall
gate for simultaneous dumping of the contents of its compartments
into the respective compartments of the loading cart hopper. Each
of the various catalyst compartments of the charging hopper is of
virtually the same dimension, thus by simply pouring catalyst
pellets into all of the compartments and wiping away the excess in
precisely the same manner at each loading of the charging hopper,
assurance is provided that each of the measuring compartments of
the charging hopper contains virtually the same quantity of
catalyst pellets. The charging hopper is filled at a catalyst
source location that is remote from the upper tube sheet of the
reactor and is carried manually to the loading cart and placed in
assembly with the loading cart hopper. Its bottom wall gate is then
moved to its open position for dumping the measured catalyst of
each of the charging hopper compartments into respective
compartments of the loading cart hopper. Further, by providing a
charging hopper loading machine for mechanized loading of the
charging hopper, virtually the same total volume of catalyst
material can be discharged from the charging hopper into the
dispensing hopper of the loading cart during each dispensing cycle.
The charging hopper loading machine receives an empty charging
hopper and, upon activation of its mechanism, the machine moves the
empty charging hopper to a position for filling and opens a gate of
its catalyst hopper and, while being vibrated, discharges a
sufficient volume of catalyst pellets onto the upper portion of the
charging hopper to overfill each of the measuring compartments
thereof As the machine then returns the overfilled charging hopper
to the start position a leveling brush, which may be statically
located or movable, i.e., rotatable, will remove the excess
catalyst pellets, thus leaving the multiple measuring compartments
of the charging hopper with a precisely volumetrically measured
quantity of catalyst. The filled charging hopper is then closed and
latched to ensure against spillage and is carried from the loading
facility to the catalyst loading cart and assembled with the hopper
of the cart. When the lower gate of the charging hopper is then
opened the volumetrically measured catalyst of each of the charging
hopper compartments will descend into respective dispensing
compartments of the hopper of the cart. The net result, therefore,
is the systematized, low cost, accurate charging of the multiple
tubes of a catalytic reactor, thus providing optimum results from
the reactor charging procedure and at the same time providing
significant labor savings as compared to conventional manual
reactor servicing operations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The various objects and advantages of this invention will
become apparent to those sidled in the art upon an understanding of
the following detailed description of the invention, read in light
of the accompanying drawings which are made a part of this
specification and in which:
[0031] FIG. 1 is a side elevational view of a catalyst loading cart
representing a preferred embodiment of the present invention;
[0032] FIG. 2 is an end view of the catalyst loading cart taken
along line 2-2 of FIG. 1;
[0033] FIG. 3 is a plan view of the catalyst loading cart of FIGS.
1 and 2;
[0034] FIG. 4 is a partial sectional view of the catalyst charging
manifold of the apparatus shown in FIGS. 1-3;
[0035] FIG. 5 is an elevational view of the charging manifold of
FIG. 4;
[0036] FIG. 6 is a plan view of the charging manifold of FIGS. 4
and 5;
[0037] FIG. 7 is an isometric illustration of a vacuum type vent
hood that is mounted above the catalyst transfer tray and which
serves to remove catalyst dust that might be present in the
tray;
[0038] FIG. 8 is a elevational view of the catalyst dust hood of
FIG. 7;
[0039] FIG. 9 is an end view of the catalyst dust hood of FIGS. 7
and 8;
[0040] FIG. 10 is an isometric illustration of a vacuum type dust
pan that is mounted below the catalyst transfer tray and in
registry with dust tailing openings of the catalyst transfer
troughs for the purpose of removing the catalyst tailings or dust
as the catalyst pellets move through the troughs of the tray;
[0041] FIG. 11 is an end view of the catalyst dust pan of FIG. 9
and 10;
[0042] FIG. 12 is a plan view of the catalyst dust pan of FIGS.
9-11;
[0043] FIG. 13 is a side elevational view of the catalyst dust tray
of FIGS. 9-12;
[0044] FIG. 14 is a side elevational view of a catalyst loading
cart representing an alternative embodiment of the present
invention wherein a lower charging manifold thereof is subject to
controllable raising and lowering relative to the reaction tube
openings to be charged thereby,
[0045] FIG. 15 is an electronic schematic illustration of a portion
of the control circuitry for the catalyst loading cart of the
present invention illustrating the vibration trimmer system and the
automatic accelerometer controlled trimming circuitry for
controlling vibration characteristics of the vibratory tray
responsive to catalyst weight;
[0046] FIGS. 16 and 17 are electrical layout illustrations showing
features of the electronic control circuitry for the catalyst
loading cart of this invention;
[0047] FIG. 18 is an isometric illustration of a catalyst charging
hopper which is utilized to quickly transfer measured quantities of
catalyst pellets to the respective hopper compartments of the
catalyst loading cart;
[0048] FIG. 19 is an end elevational view of the catalyst charging
hopper of FIG. 15 showing its position relative to the hopper
structure for charging the hopper compartments with catalyst
material;
[0049] FIG. 20 is a front elevational view of an automated
mechanism for accurately loading a catalyst charging hopper so that
each of the multiple measuring compartments of the catalyst
charging hopper will contain virtually identical volumes of
catalyst pellets;
[0050] FIG. 21 is a side elevational view of the automated catalyst
charging hopper loading mechanism of FIG. 20, with the dust shroud
thereof removed to enable visualization of the operational
components thereof
[0051] FIG. 22 is a partial front elevational view of the automated
catalyst charging hopper loading mechanism of FIGS. 20 and 21,
showing the access doors thereof in their closed positions.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0052] Referring now to the drawings and first to FIGS. 1-3, a
mechanized catalyst loading cart that in constructed in accordance
with the principles of the present invention is shown generally at
10 and incorporates a cart framework, shown generally at 12, having
a wheeled base structure shown generally at 14. The wheeled base 14
is in the form of a rectangular framework base having side members
16 and end members 18 from which depend support legs 20 that are
located at respective corners of the rectangular base. The wheeled
base structure 14 is provided with a plurality of casters 22 which
enable the cart to be rolled along any horizontal surface, such as
the horizonal upper tube sheet of a catalytic reactor. To isolate
the vibration of the loading cart mechanism from the upper tube
sheet of the reactor, cushioned feet 24 are provided for each of
the legs 20. These cushioned feet rest upon the upper tube sheet of
the reactor after the cart has been properly located for dispensing
of catalyst into particular reaction tubes.
[0053] It is desirable to provide the loading cart for ease of
movement on the upper tube sheet of the reactor so that the
charging manifold of the cart, to be discussed hereinbelow, can be
easily positioned with respect to reactor tubes to be charged. This
feature is accomplished by connecting the casters 22 to the wheeled
base 14 by a retraction mechanism that retracts the casters to
enable the cushioned feet 24 of the wheeled base 14 to rest on the
upper tube sheet of the catalytic reactor. The cushioning activity
of the cushioned feet 24 is provided by rubber mounts which are
attached to the bottom of each leg and serve to isolate the
vibration of the vibratory tray to the catalyst loading cart.
Retraction of the casters 22 is accomplished by a linear motor 26
which may conveniently take the form of an air energized cylinder
and piston assembly or an electrically energized linear motor or
the like which operates through a mechanical linkage for
accomplishing pivotal movement of retraction plates 28 about
respective pivots 30 thus raising or lowering the casters which are
mounted to the retraction plates. When the retraction plates 28 are
pivoted upwardly about their respective pivots 30 in essence the
wheeled base 14 is lowered, causing the cushioned feet 24 of the
base to come into supporting contact with the upper tube sheet of
the reactor. Thus, in the retracted positions of the castors, the
wheeled base 14 will be substantially immoveable with respect to
the upper tube sheet of the reactor and thus will not move
inadvertently as catalyst material is being dispensed into specific
reaction tubes.
[0054] The framework 12 of the catalyst loading cart is provided
with an upper moveable frame section shown generally at 32 and
incorporating a pair of frame connectors 34 that are connected to
pivot members 36 to thus permit the frame structure 32 to be
pivotally moveable relative to the wheeled base 14. This pivotal
movement may be controlled by a linear actuator 38 having its ends
connected respectively to horizontal members 40 of the frame 32 and
to the rectangular frame 16 of the wheeled base. The frame 32 also
incorporates upright members 42 that are interconnected with the
horizontal members 40 as shown in FIG. 1 and are provided with
lateral handle support members 44 to which a transverse handle 46
is connected. A worker using the wheeled mechanized catalyst
loading cart of this invention will grasp the transverse handle 44
and will be able to manipulate the position of the cart relative to
particular reaction tubes of the catalytic reactor. For feeding of
pelletized catalyst material, it is desirable to contain the
catalyst within a compartmentalized hopper and to feed the catalyst
material by vibration from individual compartments of the hopper to
individual troughs of a catalyst transfer tray and then to
controllably drop the catalyst pellets from the tray into
individual reaction tubes at a controlled drop rate that will
ensure proper compaction of the catalyst within the reaction tubes
without allowing the catalyst material to become bridged and to
develop voids within the reaction tubes. Accordingly, the catalyst
loading cart of this invention is provided with a pair of vibratory
tray supports 48 having their lower ends connected to the wheeled
base structure 14 and having a transverse member 50 interconnecting
the upper ends thereof. A pair of lateral support members 52 have
their ends connected to the transverse support member 50 and
provide for support of an electrical control panel module 54 in the
form of a generally rectangular enclosure to be discussed in detail
hereinbelow.
[0055] A vibratory tray 56 is supported in generally horizontally
oriented manner by means of a pair of electronic vibrator elements
58 and 60 that are each bolted or otherwise connected to a
horizontal support structure 62 of the wheeled base 14. The
horizontal support 62 is positioned by a pair of upright support
members 64 which are fixed to the rectangular base framework of the
wheeled base structure 14. The vibratory tray as shown in FIG. 1 is
fixed to the upper portions of each of the vibrators 58 and 60 so
that the tray is oscillated by the vibrators. The vibratory tray 56
is provided with a plurality of spaced parallel partitions 66,
dividing the tray into a plurality of catalyst transfer troughs or
grooves 68 shown in FIG. 3. The catalyst transfer troughs are.
arranged so that at one end they are located beneath the bottom
outlet opening 70 of a multi-chamber hopper 72 which is mounted
such as by welding to the upper portion of the catalyst transfer
tray. As shown in FIG. 3, the hopper 72 is provided with a
plurality of spaced parallel internal partitions 74 defining a
plurality of internal catalyst chambers 76 which are arranged for
discharge of catalyst pellets into respective ones of the plurality
of troughs or grooves 68 of the catalyst transfer tray. Discharge
of catalyst pellets into the transfer troughs of the tray is
controlled in part by vibration of the hopper along with the tray
by the electronic vibrators 58 and 60 and in part by an adjustable
weir member 78 having a plurality of gate sections 80 each arranged
within one of the catalyst transfer troughs. The weir member is
adjusted upwardly or downwardly as desired relative to the catalyst
transfer troughs so as to control the effective size of the
discharge openings of the hopper compartments relative to the
respective transfer troughs of the vibratory tray.
[0056] One of the problems that have been found with vibratory type
feeder systems for catalyst pellets or any other small objects is
that is very difficult to achieve substantially consistent
vibratory feeding or transfer of objects so that the discharge from
each of the troughs of a vibratory tray is essentially the same. In
the case of delivery of catalyst materials, it is necessary that
the catalyst pellet drop time in each of the various reaction tubes
of a catalytic reactor be virtually the same. If catalyst pellets
are feeding faster from one or more troughs of the tray, the result
will be uneven catalyst drop rate and thus uneven compaction of
catalyst within the reaction tubes being charged. In this case
voids can occur in certain reactor tubes by bridging of the
catalyst pellets, thus resulting in differing outage of the tubes
when the loading operation has been completed. The pressure
required to force fluid through the reaction tubes will not be the
same for all tubes. Although vibrator apparatus may be adjustable
in amplitude of vibration, it is virtually impossible to adjust the
amplitude of a single vibrator device is such manner that all of
the troughs of vibratory tray can achieve essentially the same
catalyst drop rate. It has been determined that by providing two
vibrator devices such as shown at 58 and 60, each being connected
to the cross member support 62 by means of bolts 63 and by
providing trimmer adjustments for each vibrator for synchronization
thereof and a master vibrator adjustment for simultaneously
adjusting the amplitude of both vibrators to thus accomplish
precise adjustment of the drop rate of the catalyst pellets from
all of the troughs of the vibratory tray so that the catalyst
output of each of the transfer troughs is essentially the same. As
shown particularly in FIGS. 1 and 2, the electronic panel housing
54 is provided with a control panel 82 having a power switch 84, a
master potentiometer 86 for controlling electrical power input to
both vibrators and trimmer potentiometers 88 and 90 for individual
control of each of the vibrators 58 and 60. Thus, to control the
discharge rate of each of the troughs of the vibrator tray so that
the discharge rates of the multiple trays are essentially
identical, the trimmer adjustments 88 and 90 may be individually
manipulated. When each of the troughs is outputting substantially
identical volumes of catalyst pellets through selectively
controlled vibration of the vibrators 58 and 60, then the drop rate
of the catalyst pellets from the multiple troughs of the tray may
be increased or decreased simply by appropriate adjustment of the
master potentiometer 86 which causes simultaneous amplitude
adjustment of both of the vibrators while the previously adjusted
trimming control is maintained.
[0057] It is desirable that the catalyst pellets that are being
loaded into the reaction tubes of the reactor be free of catalyst
dust since the dust can interfere with fluid transition through the
catalyst pellet mass and thus interfere with the optimum reaction
that is designed. Catalyst pellets however are typically delivered
in premeasured bags and the bags will typically contain a small
quanity of catalyist dust and tailings that will typically be
introduced into the hopper compartments along with the catalyist
material. It is desirable to ensure that this dust be separated
from the catalyist pellets before the pellets are dropped into the
reactor tubes. Even further, catalyst materials are known to have a
carcengenic characteristic; thus it is highly desirable to ensure
that workers involved in catalyist loading operations are protected
against contact with catalyst dust and tailings and that they be
protected from breathing the catalyist dust. In one form of the
invention, as shown in FIGS. 1-3, the catalyist dust or tailings
are caused to drop from each of the catalyst troughs into a
receptacle that receives and secures the catalyst tailings to
prevent them from invertially entering the reactor tubes or
becoming air entrained dust that contaminates the working
environement about the catalyst loading operation. In another form
the of the invention, as shown in FIG. 11, the loading cart is
provided with a vaccum engerized dust or tailing removal system
including an evacuated trough and an evacuated hood that cover at
least a portion of the catalyst loading troughs and serve to
forcefully remove the dust and tailings from the catalyist pellets
so that they can be dropped substantially clean into the reactor
tubes. In fact, the catalyist loading cart of FIGS. 1-3 if desired,
may be provided with a vacuum controlled dust and tailing removal
system instead of the gravity removal system that is shown.
[0058] As is evident from FIG. 3, the bottom surface that defines
the bottom of each of the catalyist transfer troughs 68 defines a
multiplicity of small openings 92 which cover only a small section
of the length of each of the troughs. After the catalyst pellets
and any dust or tailings that accompany the pellets have been
deposited from the hopper compartments into the respective troughs,
vibration of the tray will cause the catalyst and the dust and
tailing contaminents through traverse along the tray until the
openings 92 are reached. The dust and tailings will then fall
through the multiple small openings 92 thus allowing the catalyst
pellets to continue forward movement by the vibratory action of the
tray to the respective discharge openings 69 of the catalyst
transfer troughs.
[0059] As shown particularly in FIG. 1, a support post 94 projects
upwardly from a central framework section 96 of the wheeled base
14. A transverse support member 98 has its intermediate portion
connected to the upper end of the support post 94 as shown
particularly in FIG. 2. A plurality of lateral support members 100
are bolted or otherwise connected to the lateral support 98 and in
turn provide support for a receptacle 102 having its upwardly
facing opening 104 arranged to receive the dust and tailings that
fall through the openings 92 of the vibratory catalyst tray. The
receptacle 102 is arranged so that is does not phyiscally touch the
structure of the vibratory tray and thus does not vibrate along
with the tray. Any dust and catalyst tailings that fall into the
receptacle 102 will simply be contained until the receptacle has
become sufficiently full that it should be emptied. The receptacle
102 is provided with a releasable connector 106 so that the tray
can be released from the supports 100 simply by loosening the
connector.
[0060] At the end of the vibratory tray, opposite the electronic
vibrator apparatus, is provided a plurality of discharge tubes 108
that extend downwardly from the respective discharge openings 69.
These discharge tubes are arranged to receive elongate flexible
tubes 110 which are secured thereto by means of a plurality of
retainer bands 112. At their lower ends, as shown in FIG. 4, each
of the flexible polymer tubes 110 is secured to the respective
upper end of a drop tube member 112 by means of a metal retainer
band 114. Each of the drop tubes 112 is secured such as by welding
to a transverse structural member 116 so that each of the drop
tubes is maintained in parallel relation and maintained in optimum
spaced relation for dropping catalyist pellets through the bottom
opening 118 of each of the drop tubes. The transverse structural
member 116 secures the respective drop tubes in a particular spaced
and oriented relation that matches the spacing and orientation or
pattern of the reactor tubes to be filled. The drop tubes and the
structural member 16 thus cooperatively define a charging manifold
for simutanous orientation of the drop tubes with respect to the
reaction tubes to be filled. For location of the charging manifold
relative to the reactor tubes, an elongate structural member 120 is
connected to the structural member 116 such as by welding. A pair
of locator pins 122 project downwardly from respective extremities
of the structural member 120 and have locator guide projections 124
of smaller dimension than the locator pins for ease of entering
adjacent reactor tubes and for thus locating the charging manifold
in proper position for dropping catalyist pellets into muliple
selected reaction tubes. Typically, the charging manifold will have
ten drop tubes, each associated with a particular flexible tube 110
and thus associated with a respective catalyist transfer slot of
the vibratory tray. It should be borne in mind however that the
catalyst loading cart may have more or less catalyst transfer slots
and charging manifold tubes as is suitable for the needs of the
user.
[0061] To provide for efficient removal of catalyst dust, which can
contaminate the environmental air of the catalyst loading
environment, and to also achieve removal of catalyst tailings, both
of which can interfere with proper operation of the catalytic
reactor, the catalyst loading cart of FIGS. 1-3 may be provided
with a vacuum removal system such as is shown in FIGS. 6-12. For
catalyst dust removal, a vent hood 126 shown in FIG. 7 may be
pivotally mounted to the upper portion of the vibratory tray. The
vent hood is pivotal to a position on top of the vibratory tray for
dust removal and is pivotal to an out of the way position for
access to the transfer slots and bottom openings of the vibratory
tray such as for the purpose of the cleaning. The vent hood is
typically composed of sheet metal and defines side panels 128 and
130 that are oriented in angular relation. A handle 132 is fixed to
the apex of the vent hood such as by welding and is used for manual
pivoting of the vent hood. The vent hood is also provided with end
panels 134 and 136 that are fixed to respective ends of the side
panels 128 and 130 and project beyond the side panel 130 to define
end panel support sections 138 and 140 having mounting flanges 142
and 144 at respective ends thereof. Hinge members 146 are mounted
to the flanges 142 and 144 as shown in FIG. 9 to thus provide for
pivotal mounting of the hood on the structure of the vibratory
tray. The end panel 134 is also provided with a tubular vacuum
connection 148 to which a vacuum tube will be connected. During
operation, a suitable source of vacuum, such as the vacuum source
of a manufacturing facility utilizing a catalytic reactor, will be
connected. Thus, most of the catalyst dust that might otherwise be
liberated into the environmental air during the catalyst charging
operation will be evacuated from the vent hood through the vacuum
connection 148.
[0062] When a vacuum purged dust and tailing system is desired, a
vacuum pan may be provided as shown in FIGS. 10-13. The vacuum pan,
shown generally at 150 in FIG. 10, has side panels 152 and 154 to
which are connected end panels 156 and 158 so as to define a
generally rectangular enclosure. Mounting flanges 160 and 162
project laterally from the bottom portions of the end panels 156
and 158 and provide for support of the vacuum pan by the cart
framework in position for receiving tailings and dust that fall
through the multiple openings 92 of the bottom of the vibratory
tray. The pan structure also defines downwardly converging side
panel sections 164 and 166 which are connected to the respective
side panel sections 152 and 154. A triangular end panel section 168
extends downwardly from the end panel section 156 and is connected
respectively to the side pane: sections 164 and 166. These panel
sections are assembled so that any dust or tailings that fall into
the pan will descend downwardly to a pan bottom 170. A vacuum
connection 172 is fixed to the end panel section 168 and also
provides for connection of a vacuum tube of a vacuum supply so that
dust and tailings from the pan will be transported by the vacuum
away from the loading site to suitable facility for reclamation or
disposal. During use, the support flanges 160 and 162 simply rest
on the framework structure of the catalyst loading cart so that
from time to time the pan structure 150 maybe removed from the cart
and cleaned of any residual catalyst dust that might be present on
the inside surfaces thereof.
[0063] With reference now to FIG. 14, an alternative embodiment of
the present invention is shown generally at 180 which comprises an
catalyst loading cart mechanism having a catalyst charging manifold
that is adapted for upward and downward movement relative to the
vibratory tray thereof so as to facilitate catalyst loading
operations even under circumstances where the retractable wheels
thereof are permitted to remain extended. This type of catalyst
loading apparatus may also facilitate elimination of the
retractable wheel assembly of a catalyst loading cart so that
casters or wheels of other types may be physically attached to the
framework so that the cart is always capable of rolling on the tube
sheet surface of a reactor. The casters of the cart can be provided
with brakes to prevent inadvertent movement of the catalyst loading
cart during a charging operation. The catalyst loading cart 180 of
FIG. 14 will incorporate a framework structure shown generally at
182 which may take the general form shown in FIGS. 1-3. The
framework defines a generally rectangular framework base 184 having
a pair of vibrator supports 186 and 188 projecting upwardly
therefrom and having cross members 190 and 192 to which structural
components of a pair of electronic vibrators 194 are mounted.
Vibrator elements 196 and 198 of the vibrators are operatively
connected to a generally horizontally oriented vibratory tray so
that electronic activation of the vibrators will induce vibratory
motion to the vibratory tray. A hopper 202 is welded or otherwise
fixed to the upper portion of the vibratory tray and will take the
form shown in FIGS. 1-3, having a plurality of internal hopper
compartments and being closed by a simple removable or pivotal
closure member 204. The vibratory tray may be of the same
configuration and dimension as shown in FIGS. 1-3, having an
adjustable weir 206 for controlling discharge of catalyst pellets
from the multiple compartments of the hopper. The vibratory tray
structure will also define a bottom panel having a section with a
multiplicity of openings such as shown at 92 in FIG. 3 for
permitting catalyst tailings and dust to drop therethrough into a
receiving pan. The vibratory tray will also be provided with a vent
hood such as shown at 208 and a collection pan structure shown at
210. The vent hood and collection pan may both be subject to
continuous evacuation via vacuum connection tubes 212 and 214 to
which vacuum conduits are connected in the same manner as described
above in connection with FIGS. 7-13.
[0064] For retractable mounting of casters to thus enable the
catalyst loading cart to rest on its cushioned legs 216 and 218 or
to rest on caster wheels 220 and 222, a pair of caster positioning
plates 224 and 226 are connected by pivots 228 and 230 to
respective transverse structural supports 232 and 234 of the cart
framework structure. A centrally located linear actuator 236 is
also fixed at the lower end thereof to the framework 182 and is
arranged to drive connectors or linkages for accomplishing pivoting
of the wheel support plates 224 and 226 about their respective
pivots and thus retract the caster wheels 220 and 222 upwardly to
permit the cushioned legs 216 and 218 of the framework to rest on
the upper tube sheet of the catalytic reactor. Also, if desired,
the same type of actuator energized wheel retraction system that is
shown in FIGS. 1-3 may be incorporated within the catalyst loading
cart of FIG. 14. As a further alternative, if desired, the caster
retraction mechanism may be eliminated and the caster wheels 220
and 222 may be connected directly to the leg structure of the
loading cart framework. For purposes of control the loading cart
mechanism 180 is provided with a control housing or consol 238 that
may conveniently take the form shown at 54 in FIGS. 1-3.
[0065] It is considered desirable where the catalyst loading cart
mechanism is provided with retractable caster wheels or not, to
provide a catalyst loading manifold that can be independently
raised and lowered to promote the efficiency of the catalyst
loading operation. To accomplish this feature, the vibratory tray
200 is provided with a plurality of catalyst drop tubes 240 that
project downwardly from the vibratory tray and are each in
communication with respective catalyst transfer slots of the
vibratory tray. The upper ends of a plurality of flexible conduits
242, typically composed of a polymer material, are connected to
each of the drop tubes by means of metal retainer bands 244 while
the lower ends of the flexible conduits are connected to upwardly
projecting tubular connectors 246 of a fixed manifold 248 by metal
retainer bands or clamps 250. The fixed manifold 248 is immovably
connected to the framework 182 such as by bolting and is provided
with a plurality of downwardly projecting telescoping tubes 251
which are telescopically received within a plurality of telescoping
passages 252 of a movable charging manifold 253. The charging
manifold, when in its lowermost position, is adapted to rest on the
reactor tube sheet 254 as shown in FIG. 14 and serves to conduct
dropping catalyst pellets into selected reactor tubes 255. For
guided movement of the charging manifold, guide bars or tracks 256
are fixed to framework legs 257 and are movably engaged by a slide
member 258 which is fixed to the movable charging manifold. A
linear actuator 259 is interposed between the fixed manifold 248
and the movable charging manifold 253 and is operative to move the
charging manifold downwardly as needed to position the charging
manifold in registry with selected reaction tubes and upwardly to
permit movement of the catalyst loading cart between tube charging
operations. As the charging manifold is moved upwardly and
downwardly the telescoping tubes 251 maintain their telescoping
relationship within the manifold passages 252. For locating the
charging manifold in charging position with respect to a group of
reactor tubes to be simultaneously charged with catalyst pellets,
the charging manifold is provided with a manifold locator structure
260 having a pair of locator pins 261 that are in fixed relation
with the charging manifold and are adapted to be received within
reaction tube openings that are located adjacent the reaction tubes
to be charged. When the locator pins are inserted into selected
reaction tubes during lowering of the charging manifold into
engagement with the tube sheet the plurality of charging passages,
typically 10, will move into charging registry with a like number
of reaction tubes to be simultaneously charged with catalyst
pellets. If desired, the manifold locator structure may
conveniently take the form shown in FIG. 4.
[0066] For purposes of electrical operation and control, the
catalyst loading cart of this invention is provided with electronic
circuitry which is shown by FIGS. 15, 16 and 17, with FIGS. 16 and
17 showing the layout of circuit components of the control panel
and within the control consol 54 or 238 as the case may be. As
shown in FIG. 15, the electronic circuitry shown generally at 280
is provided with a disconnect switch assembly 282 through which the
circuitry is connected to a suitable source of electrical energy,
such as the power supply system of a manufacturing facility. The
circuitry which incorporates a neutral conductor 284 and a positive
conductor 286 is provided with a master fuse 288 which will
interrupt the circuit in the event of any power overload to thereby
protect the circuitry from overload damage and to ensure against
damage to other electronic components that are controlled by the
circuitry. A start and run conductor 290 is connected across
conductors 284 and 286 and includes a fuse 292 that will interrupt
the circuit in the event of circuit overload. The circuit 290 is
also provided with a stop switch 294 which will be manually
manipulated by the user of the equipment when shut down of the
circuitry is desired. The circuitry also incorporates a start and
run circuit incorporating an normally open start switch 296 which
will energize a run circuit 298 across a relay contact 300. The run
circuit is also provided with a protective fuse 302 and is
connected for energy supply to a controller circuit 304. The
controller circuit is provided with a master potentiometer circuit
306 having a potentiometer 308 which is also shown as a panel
component of the control panel shown in FIG. 16. The stop and start
switches 294 and 296 are also shown in the panel display of FIG.
16. The potentiometer 308 is connected with a mode switch 310
having one operative position as shown in full line in FIG. 15 and
a second operative position as shown in broken line. The mode
switch is also shown in the inside cover panel display of FIG. 16
where it is positionable between manual and automatic mode
settings. In the broken line position of the mode switch, the
master potentiometer circuit is operative via conductors 312 and
314, with a resistor circuit 316 connected across these same
conductors. The master control conductors 312 and 314 receive a
four volt 20 milliamp dc input signal as shown in FIG. 15.
[0067] The circuitry is also provided with trimmer circuits 318 and
320 which are both connected to a controller circuit 322 and
connected to neutral conductor across an SCR 324 with the gate
voltage of the SCR being provided by a gate circuit 326 of the
controller circuit. The trimmer circuits are provided respectively
with potentiometers 328 and 330 which control adjustment of the
amplitude of the vibration of the vibrators 58 and 60 of FIGS. 1-3
and vibrators 94 of FIG. 14. Vibrator trimmer adjustment is
accomplished by controlling electromagnet circuits 332 and 334 via
the trimmer potentiometers 328 and 330. As mentioned above, by
trimmer adjustment of each of the dual vibrators of the vibratory
tray, the characteristics of tray vibration can be controlled to
efficiently transfer catalyst pellets along the length of the
individual slots or troughs and to achieve virtually identical
catalyst drop time from each of the troughs of the vibratory tray.
This feature facilitates efficient and even loading of catalyst
material into the reaction tubes to thereby achieve the result of
quite even catalyst compaction within the tubes so that the
resulting performance of the catalytic reactor will be at its
optimum level. After the trimmer potentiometers have been properly
adjusted, to vary the catalyst drop rate into the reaction tubes,
the master potentiometer 308 may be appropriately adjusted to
increase or decrease the amplitude of tray vibration and thus the
catalyst drop rate. The vibratory apparatus, when controlled in the
manner shown by FIG. 15, will achieve repeatable quality loading
operations well beyond the quality of catalytic reactor loading
that can be accomplished even by hand loading operations.
[0068] As mentioned above, one of the objections that can be
encountered in automated catalyst loading operations is that
changes in the drop time of catalyst will vary responsive to the
decreasing weight of the catalyst material within the loading
hopper. When the catalyst loading hopper is full of catalyst
pellets, the weight of the catalyst material will cause the
vibratory tray to have small amplitude vibrations (because of the
combined weight or mass of the vibratory tray, the hopper and the
catalyst contained within the hopper) thereby achieving a
particular catalyst drop rate even though the rate of vibration
does not change. As the weight of the catalyst material within the
hopper then decreases during a loading cycle, as the catalyst in
the hopper is depleted, the amplitude of the vibrations of the
vibratory tray will increase, with maximum vibration amplitude
occurring as the hopper chambers become nearly empty. Even though
the rate of vibration does not change, the amplitude of the
vibration changes significantly and causes consequent variation in
the drop rate of the catalyst during the charging cycle. It is
desirable, therefore, to provide a suitable system for controlling
the vibration of the vibratory tray so that the amplitude of the
vibratory movement of the vibratory tray remains substantially
constant during a catalyst loading cycle regardless of the changes
of catalyst weight within the hopper. This feature is accomplished
through the provision of catalyst weight related input signals that
are then conditioned and provided to the controller circuit 304 for
controlling the amplitude output of the electronic vibrators 58 and
60 responsive thereto. This is achieved in accordance with the
present invention by providing an accelerometer 336 which is
mounted on the vibratory tray 56 and provides a weight sensitive
signal output via conductors 338 and 340 reflecting the amplitude
of tray vibrations. These weight sensitive electronic signals are
then processed by a data signal conditioner circuit 342 which is
powered by a 24 volt dc power supply 344 and provides conditioned
output signals via conductors 346 and 348 to the control circuit
304 as shown in FIG. 15. During a catalyst loading cycle, the
weight responsive signals of the accelerometer 336 will have
characteristics that change during the complete catalyst charging
cycle. The conditioned, weight responsive output signals received
by their controller circuit are then used to vary the operational
control of the electronic vibrators 58 and 60. In this manner, the
vibrators are controlled such that the vibrational amplitude
remains substantially constant from the beginning to the end of a
catalyst charging cycle so that the drop rate of catalyst from the
vibratory tray will remain substantially constant throughout the
catalyst charging cycle.
[0069] As mentioned above, catalyst material is typically
premeasured into small bags and is provided at a supply point
adjacent the tube sheet of the reactor or in a container on the
tube sheet. To charge individual reactor tubes by a manual charging
procedure, a funnel is located with its discharge spout inserted
into the reactor tube to be charged. The worker will then open a
premeasured bag and carefully pour the catalyst contents thereof
into the funnel with pouring being manually controlled so that the
drop rate of the catalyst is controlled according to the drop rate
that is desired. Any catalyst dust and tailings that are poured
from the bags into the funnel will logically fall into the reactor
tube being charged. In the event the worker should inadvertently
drop the catalyst bag, some catalyst material can enter other
reactor tubes. When this occurs the improperly filled tubes of the
reactor will likely be emptied of catalyst and subsequently
properly recharged. Should the worker pour the catalyst into the
funnel at a rate that is too slow or too fast the reaction tube
being charged will be subject to improper compaction, bridging
voids, etc.
[0070] When the catalyst loading cart of the present invention is
employed, it is desirable during catalyst loading operations that
the catalyst loading cart remain located in the vicinity of reactor
tubes to be filled and that it be periodically charged with
catalyst pellets. To replenish its hopper with catalyst pellets, a
suitable means be employed to transport measured quantities of
catalyst material from a supply point to the catalyst loading cart.
It is also important to accomplish transport of the catalyst
material from the supply point to the tube sheet of the reactor and
to the catalyst loading cart in such manner that inadvertent
spillage of catalyst material will not occur. It is also desirable
to provide a system for charging the various compartments of the
loading cart hopper with precisely measured quantities of catalyst
pellets so that the production of the charging operation may
continue at a high level without risking improper hopper charging.
To accomplish these features, a portable catalyst charging hopper
may be provided as shown generally at 350 in FIGS. 18 and 19. The
catalyst charging hopper is basically a rectangular housing
structure having parallel side walls 352 and 354 and parallel end
walls 356 and 358. Internally, the charging hopper is provided with
a plurality of internal partitions 358, being the same number of
partitions as are provided within the hopper 72 shown in FIGS. 1-3
and defining the same number of internal hopper charging chambers
as the compartments of the hopper of the catalyst loading cart. For
example, if the hopper of the catalyst loading cart is provided
with ten internal chambers for feeding catalyst to ten elongate
troughs of the vibratory tray, the charging hopper will also be
provided with ten internal catalyst chambers. Each of the chambers
of the charging hopper will be of identical internal dimension for
ensuring charging of each of the chambers of the loading cart
hopper with substantially identical volumes of catalyst.
[0071] The bottom of the charging hopper is open but is temporarily
closed by a slide plate or gate 362 which is movable through an
elongate slot 364 of the charging hopper side wall 352 and guided
by internal guides within the charging hopper. When the charging
gate 362 is fully inserted into its slot 364, it forms a temporary
bottom wall for the charging hopper and serves to retain catalyst
pellets within the respective catalyst chambers 360. The charging
gate is movable from the closed position to the cpen or withdrawn
position shown in FIG. 18 to dump catalyst pellets from the
respective chambers 360 thereof into respective hopper compartments
76 of the hopper 72. The charging hopper is also provided with a
closure panel 366 which is connected by one or more hinges 368 to
the upper end side wall 354. The closure panel 366 and the side
wall 352 are provided with interlocking latches that will secure
the closure in its closed position after it has been loaded with
catalyst material. For the purpose of catalyst loading, the slide
gate 362 will be inserted into the side wall slot 364 to its full
extent and catalyst material will be poured into the respective
chambers 360. Typically, for rapid but accurate loading of the
charging hopper, the chambers 360 will be overfilled and a screed
member having a straight edge will be used to scrape away the
surplus catalyst. The upper ends of each of the partitions 359 are
at the same level as the upper ends of the side and end walls of
the charging hopper. When the charging hopper has been filled in
this manner the catalyst charges of each of the charging
compartments thereof will contain virtually the same volume of
catalyst pellets.
[0072] As shown in FIG. 19, a lower portion of the charging hopper,
below the slide gate opening 364, is inserted into the upper end of
the hopper 72 of the catalyst loading cart. After the charging
hopper has been so positioned, the slide gate 362 may be grasped
and moved to the open or withdrawn position shown in FIG. 18, thus
dropping the catalyst material within the hopper chambers 360 into
the respective hopper compartments of the hopper 72. The charging
hopper is adapted to be carried by a single worker and incorporates
handles 368 and 370 mounted to the respective end walls which
facilitate its manual lifting and carrying.
[0073] By employing the catalyst charging hopper, it becomes
unnecessary to accomplish any catalyst loading immediately above
the reactor and under circumstances when it is possible to
inadvertently drop catalyst pellets on the reactor tube sheet and
into the reactor tubes. A source of catalyst pellets will be
maintained externally of the circular bounds of the reactor shell,
typically in an anteroom located to one side of the reactor shell.
Workers will locate one or more catalyst charging hoppers in the
anteroom and, after closing the sliding gate thereof, will fill
each of the multiple chambers thereof with catalyst pellets. These
multiple chambers are each of the same dimension and configuration
and will each contain a precisely measured volume of catalyst
material. After the catalyst charging hopper has been properly
filled, its closure will be closed and latched to secure the
catalyst pellets within the multiple compartments thereof. Even
under circumstances where a worker should fall while carrying the
charging hopper on the reactor tube sheet, the charging hopper will
maintain its integrity and contain the catalyst against potential
spillage. The worker will then position the charging hopper in
registering assembly atop the hopper of the catalyst loading cart
as shown in FIG. 19, after which the worker will puff the slide
gate closure to its open position as shown in FIG. 18, thus dumping
the measured charges of each of the multiple compartments thereof
into respective compartments of the hopper of the catalyst loading
cart. Thereafter, the catalyst charging hopper is returned to the
anteroom, where it is again loaded with catalyst pellets as
indicated above in preparation for quick, efficient and accurate
loading of the hopper compartments of the loading cart with precise
volumes of catalyst pellets. By using a number of catalyst charging
hoppers the reaction tube charging operation can be rapidly
conducted without in any manner sacrificing the integrity and
accuracy of the reactor charging operation. A reactor charging
operation, which might require a two week period to complete by
hand loading operations, can be done in three to four days time and
with much improved accuracy when a catalyst loading cart is
employed having the capability for simultaneous 10 tube mechanized
reactor charging. The labor savings of such a mechanized reactor
charging operation is obvious.
[0074] Referring now to FIGS. 20 and 21, automated apparatus for
measured filing of multi-compartment charging hoppers is shown
generally at 380 and comprises a base structure shown generally at
382 having vertically oriented support legs 384 and horizontal
strut members 386 having the ends thereof connected to the support
legs. Thus, the base structure 382 is of generally rectangular
configuration. The upper portion of the base structure is defined
by a generally horizontal platform 388 having a pair of parallel
rails 390 and 392 fixed thereto. The parallel rails define a guide
track for a charging hopper transfer trolley to be discussed in
detail hereinbelow. Beneath the horizontal platform 388 there is
provided a catalyst overage chute having inclined walls and a
bottom opening 396 for directing descending catalyst pellets from
the overage chute opening into a catalyst overage receptacle 398
that is adapted to rest on a floor 400 or other suitable surface
within the rectangular enclosure defined by the base structure
382.
[0075] A bulk catalyst hopper 402 is supported above the base
structure 382 in such manner that catalyst pellets descending from
a bottom discharge opening 404 of the hopper will fall into the
multiple measuring compartments of a charging hopper 350, described
above in connection with FIGS. 18 and 19. The bulk catalyst hopper
402 is provided with a bottom closure gate 406 having pivot arms
408 and 410 that are pivotally connected to tapered side walls 412
and 414 of the bulk catalyst hopper. The discharge control gate 406
is adapted for controlling movement by a gate operator 416 in the
form of a linear pneumatic motor. To accommodate catalyst charging
hoppers of differing height, the bulk catalyst hopper 402 is
adjustably support so that the discharge opening at the bottom of
the hopper can be selectively positioned with respect to the upper
portion of a charging hopper. To facilitate such adjustable
support, a plurality of hopper lift jacks 418 are connected to the
upper portion of the base structure 382 preferably extending
upwardly from the horizontal platform 388. Although the hopper lift
jacks 418 are shown to be of the manually operable variety having
rotatable crank handles 420 for manually controlling operation
thereof the hopper lift jacks may also be of any suitable
mechanized variety if desired. The hopper lift jacks 418 are
provided with hopper support struts 422 having the upper ends
thereof either connected directly to the bulk catalyst hopper 402
or, as shown in FIGS. 21 and 22 having the upper ends thereof
connected to horizontally oriented hopper support elements 424 and
426. Thus, as the crank handles 420 of the hopper lift jacks 418
are rotated, the bulk catalyst hopper is raised or lowered
depending upon the direction of handle rotation to thereby position
the bottom discharge opening 404 of the hopper as selectively
desired relative to the charging hopper 350.
[0076] For charging hopper loading, it is desirable to as much as
possible eliminate any manual loading operations that would
otherwise be required so that the charging hoppers may be filled in
identically the same manner during each filling cycle so that at
each loading operation the charging hoppers will be identically
filled with accurately measured volumes of catalyst pellets. One
suitable means for accomplishing this purpose is to provide a
movable charging hopper transfer trolley shown generally at 428
which incorporates a trolley framework 430 which is adapted to
receive the bottom portion of a charging hopper and thus provide
for controlled movement of the charging hopper between a start
position where the charging hopper is available for manual access
and a fill position where the charging hopper is located to receive
discharge of catalyst pellets from the bottom discharge opening of
the bulk catalyst hopper. The charging hopper framework 430 is
provided with a plurality of trolley support wheels 432 which are
designed for guiding engagement with the rails 390 and 392 of the
trolley guide track. For controlled movement of the transfer
trolley 428, a mechanized trolley actuator 434 is provided which
may conveniently be in the form of a linear pneumatic motor having
a linear drive shaft 436 thereof connected in driving relation with
the trolley 428. The trolley actuator 434 will have the capability
for linear movement of the trolley 428 between the start and fill
positions of the charging hopper 350 relative to the bottom
discharge opening 404 of the bulk catalyst hopper.
[0077] During filling of the charging hopper 350, upon opening
movement of the discharge gate 406 of the hopper, it is desirable
to ensure adequate settling of the hopper pellets so that each of
the catalyst measuring chambers of the charging hopper will be
properly filled to thus define equally measured volumes of catalyst
in each of the measuring compartments thereof. Accordingly, the
transfer trolley 428 is provided with a vibrator 438 which is
energized during the filling cycle and which is de-energized when
the transfer trolley 428 is at positions other than the hopper fill
position. If desired, the vibrator 438 may also be energized during
a certain stage of movement of the transfer trolley from the hopper
fill position to the start position.
[0078] For control purposes, the charging filling mechanism is
provided with a pneumatic control circuit 440 and an electronic
control circuit 442. The pneumatic control circuit 440 will have an
operator circuit that is controllably connected to the trolley
actuator 434 and a hopper gate actuator circuit 446 that is
connected for control of the gate actuator 416. The pneumatic
actuator circuits 444 and 446 are controlled by solenoid or other
electromechanical valve of the pneumatic control circuit via
control signals from the electronic control circuit 442. The
electronic control circuit is provided with appropriate timing
circuits and switching for providing adjustable timing control for
the filing cycle of the charging hopper and for sequence control of
the hopper transfer trolley and the discharge control gate of the
hopper. The electronic control circuitry also includes a start
switch 448, a stop switch 450 and an emergency stop switch 452
thereby allowing operating personnel to manually initiate or stop
the charging hopper filling cycle and to manually shut-down the
system in the event emergency conditions should arise. Preferably,
the start, stop and emergency stop switches will be in the form of
lighted contact buttons thereby enabling operating personnel to
have visual indication of the operating condition of the charging
hopper filling system.
[0079] Since charging hopper filling is accomplished
volumetrically, it is desirable to ensure that each of the open
topped measuring compartments of the charging hopper 350 contain a
precisely measured volume of catalyst pellets when the charging
hopper is returned to the start position by the hopper transfer
trolley 428. One suitable means for accomplishing this feature is
to provide a catalyst leveling element that is supported by the
hopper structure or the hopper support framework and is operative
upon movement of the charging hopper by the hopper transfer trolley
from the fill position to the start position to engage and wipe or
brush away any excess catalyst from the upper portion of the
charging hopper. As shown particularly in FIG. 20, the catalyst
leveling element 454 may conveniently take the form of a rotatable
leveling brush that is rotated by an electrical drive motor 456.
After the hopper fill cycle has continued for a sufficient period
of time that all of the measuring compartments of the charging
hopper have been filled and excess volume of catalyst is present on
the upper portion of the charging hopper, the transfer trolley 428
will move the charging hopper from the fill position toward the
start position. During initial movement of the transfer trolley,
the charging hopper will be moved relative to the rotating catalyst
leveling element 454 thereby causing excess catalyst to be brushed
away from the upper portion of the charging hopper and to descend
by gravity into the overage chute 394 where it is then conducted
into the catalyst overage receptacle 398. Although the catalyst
leveling element is shown to be in the form of a rotatable motor
driven leveling brush, it is not intended to limit the spirit and
scope of the present invention to this specific structure. It
should be borne in mind that other leveling elements, such as a
stationary brush, a mechanical weir, or other suitable leveling
elements may be effectively utilized without departing from the
spirit and scope of this invention. It is only appropriate from the
standpoint of the present invention that leveling of the charging
hopper by removal of excess catalyst be accomplished in the same
manner during each loading cycle. Any suitable leveling apparatus
may be utilized that will accomplish this purpose.
[0080] During dispensing of catalyst from the hopper 402 into the
charging hopper 350 is likely to generate a small quantity of
catalyst dust simply because of the dust present on the catalyst
pellets. Since this catalyst dust may be hazardous to the health of
workers, it is desirable to ensure that the presence of catalyst
dust is minimized. For this purpose, the bulk catalyst loading
mechanism 380 is provided with a mechanical shroud having side
walls 458 and 460, a rear wall 462 and a front wall defined by a
pair of door panels 464 and 466 which are best seen in FIG. 22. The
door panels are moveable between an open position permitting access
to a catalyst charging hopper at the start position and a closed
position preventing access to a charging hopper by operator
personnel. The access doors 464 and 466 are provided with a door
lock system 468 which is integrated with the electronic controlled
circuitry so that the charging hopper loading apparatus will not
operate so long as the access doors are open. When the access doors
are closed and an electrical circuit is completed, which allows
operation of the loading system. This feature prevents operating
personnel from potential danger as the hopper transfer trolley
moves between its start and fill positions. The dust shroud thus
defines a substantially closed charging hopper filling enclosure
468 to which most of the catalyst dust will be restricted. This
enclosure is vented by a source of vacuum V that is communicated by
a vacuum conduit 470 to a vacuum connector 472 that is received at
a vent opening 474 of a shroud wall 458. Thus, during operation of
the charging hopper loading mechanism, the enclosure 468 is
continuously vented so that any catalyst dust that is liberated
into the enclosure 468 is pulled away by the vacuum vent system,
thereby permitting workers to have a relatively dust-free
environment within which to work.
[0081] As will be readily apparent to those skilled in the art, the
present invention may be produced in other specific forms without
departing from its spirit scope and essential characteristics. The
present embodiment is therefore to be considered as illustrative
and not restrictive, the scope of this invention being defined by
the claims rather than the foregoing description, and all changes
which come within the meaning and embraced therein.
[0082] In view of the foregoing, it is evident that the present
invention is one well adapted to attain all the objects and
features hereinabove set forth, together with other objects and
features which are inherent in the apparatus disclosed herein.
[0083] As will be readily apparent to those skilled in the art, the
present invention may be produced in other specific forms without
departing from it spirit or essential characteristics. The present
embodiment, is therefore, to be considered as illustrative and not
restrictive, the scope of the invention being indicated by the
claims rather than the foregoing description, and all changes which
come within the meaning and range of the equivalence of the claims
are therefore intended to be embraced therein.
* * * * *