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Jan. 4, 1949.
H. K. HOLM
v
2,458,165
METHOD AND APPARATUS FOR CONVERSION
OF FLUID HYDROCARBONS
Filed March 18, 1947
4 Sheets-Sheet l
HOPPER —
O
'
-
INVENTOR.
HfFBERT KHOLM
BY
Maw’;
A GENT 0}? AYTOFNEY.
Jan. 4, 1949.
H. K. HOLM
'
METHOD AND APPARATUS FOR CONVERSION
OF FLUID HYDROCARBONS
Filed March 18, 1947
2,458,165
‘
4 Sheets-Sheet 2
INVENTOR.
HERBERT K HOZM.
JAMQWJU
AGENT 0i‘? ATTORNE)’.
Jan. 4, 1949.
H. K. HOLM
2,458,165
METHOD AND APPARATUS FOR CONVERSION
OF FLUID HYDROCARBONS
Filed March 18, 1947
4 Sheets-Sheet 3
INVENTOR.
HERBERT (r HOLM
69M“ amul
AGENT 0R ATTORNEY
Patented Jan. 4, 1949
2,458,165
UNITED STATES ‘PATENT OFFICE
2,458,165
METHOD AND APPARATUS FOR CONVER
SION OF FLUID HYDROCARBONS
Herbert K. Holm, Chicago, Ill., assignor to Socony
Vacuum‘ Oil Company, Incorporated, a corpo
ration of New York
Application March 18, 1947, Serial No. 735,326
14 Claims. (01. 196—52)
1
2
This invention has to do with a method and
apparatus for conversion of ?uid hydrocarbons
in the presence of a particle-form solid contact
material which may or may not be catalytic in
nature.
Exemplary of the processes to which this inven
tion may be applied are the catalytic cracking
tory materials such as mullite, zirkite, or corhart
material. In order to permit practical rates of
gas ?ow through the contact material which is
maintained as a substantially compact column in
the conversion zone, the contact material should
be made up of particles falling within the size
range of about .005 to 1 inch in diameter and
conversion of high boiling ?uid hydrocarbons,
preferably .03 to 0.5 inch in diameter.
the catalytic hydrogenation, dehydrogenation,
In such processes wherein the direction of gas
aromatization, polymerization, alkylation, iso 10 ?ow through the reaction zone is countercurrent
merization, reforming, treating or desulphurizing
to the downward ?ow of the contact material, the
of selected hydrocarbon fractions. Also exem
maximum rate of gas ?ow should be limited to
plary are the thermal cracking, viscosity break
that which will not cause “boiling of the contact
ing and coking of hydrocarbon fractions in the
material” or serious interference with its ?ow
15 otherwise serious di?lculties arise such as chan
presence of heated inert, solid materials.
Typical of such processes is the catalytic crack
neling of the solid and gas ?ow and excessive at
ing conversion of hydrocarbons, it being well
trition of the solid material. In many processes
known that high boiling ?uid hydrocarbons may
such as, for example, the conversion of liquid hy
be converted to lower boiling gaseous, gasoline
drocarbons to lower boiling gaseous products it
containing hydrocarbon products by exposure to a 20 is desirable to pass the reactant ?uid downwardly
suitable adsorbent type catalytic material at tem
through the conversion zone concurrently with
peratures of the order of about 800° F. and high
the contact material ?ow. In such processes a
er and at pressures usually above atmospheric.
serious di?iculty arises in the withdrawal of gase
Sucha process has recently been developed com
ous reactants from the contact material column
mercially into a continuous cyclic process wherein
within the conversion zone. In one form of op
the solid catalyst is passed cyclically through a
eration practiced heretofore a row of inverted,
spaced, collecting troughs was positioned ‘in the
conversion zone wherein it is contacted with ?uid
hydrocarbons to eil’ect the conversion thereof and
column of contact material within the lower sec
through a regeneration zone wherein it is con
tacted with a combustion supporting gas such as
air which acts to burn o? from the catalyst a ._
carbonaceous contaminant deposited thereon in
the conversion Zone.
This invention is particularly concerned with
‘ such cyclic conversion processes or gas-solid con- :
tacting processes wherein the particle-form con
tact material moves through the conversion zone
or contacting zone as a substantially compact
column and wherein gaseous reaction products
or contacting gas and the used contact material
are separately withdrawn from the conversion or
contacting zone.
"
In such cyclic processes wherein the contact
material is a catalyst it may partake of the
nature of natural or treated clays, bauxite, inert -
carriers upon which catalytic materials such as
metallic oxid'es have been deposited or certain
synthetic associations of silica, alumina or silica
and alumina to which small amounts of. other
materials such as metallic oxides may be added '
for special purposes. In processes wherein the
contact material is not catalytic in nature its
purpose is usually that of a heat carrier and
may take any of a number of forms, for example,
spheres or particles of metals, stones or refrac
tion of the reactor and gas was withdrawn
through suitable pipes extending under the ends
of the troughs. Such an arrangement is unsatis
factory due to serious entrainment of contact ma
terial in the gaseous streams withdrawn from'the
ends of the collecting troughs.
A major object of this invention is the pro
ViSlOl
in a process wherein a gaseous material
is contacted with a substantially compact column
of particle-form contact material of an improved
method and apparatus for withdrawal of gas from
said column without substantial entrainment of
contact material particles. '
Another object of this invention is the pro
vision of an improved method and apparatus for
conversion of a high boiling ?uid hydrocarbon to
a lower boiling gaseous hydrocarbon product in a
con?ned zone in the presence of a substantially
compact column of contact material particles
?owing downwardly through said zone in the di
rection ofrthe reactant ?ow.
‘
A speci?c object is the provision in a hydrocar
bon conversion process wherein the contact ma
terial moves downwardly as a substantially com
pact column of solid particles concurrently to the
?uid reactant flow of a practical method and ap
paratus for withdrawal of gaseous conversion
9,468,165
products from said column in the conversion zone
without substantial entrainment of contact mate
4
upper section of the conversion zone. An inert
purge gas such as steam or ?ue gas’ may be in
troduced into the contact material column below
the level of gaseous reactant outlet l3 through
These and other objects of this invention will
conduit 24 for the purpose of purging gaseous re
become apparent from the following detailed de
action products from the out?owing used contact
scription of the invention. Before proceeding
material. The used contact material is trans
with the description, certain expressions em
ferred to conveyor l2, which may be a continuous
ployed herein in describing and in claiming this
bucket elevator for example, to the upper end
invention will be de?ned. The term “gaseous"
as used herein, unless speci?cally otherwise modi 10 of regeneration vessel H. The regeneration
vessel shown is of the multistage type, well
?ed, is intended broadly to cover material exist
adapted for the regeneration of spent cracking
ing in the gaseous phase under the particular
catalysts. Air or oxygen containing gas is intro
operating conditions involved regardless of what
duced from manifold 25 into several superposed
may be the normal phase of that material under
burning stages through inlet conduits 26, 21 and
ordinary atmospheric conditions. The expression
23. Flue gas may be withdrawn from these stages
“contact material,” unless otherwise speci?cally
through conduits 23, 30 and 3l_, all connecting
modi?ed, is used herein in a broad sense to cover
rial particles in the eilluent gas stream. ‘
any solid material having suitable heat carry
into outlet manifold 32.
ing and stability properties for the particular
process application in which it is employed, and
the expression is intended to broadly cover cat
alytic and non-catalytic materials.
temperature may be controlled by passing a suit
The invention may be most readily understood
by reference to the drawings attached hereto of
which Figure l is an elevational view of an ar
The contact material
able cooling ?uid through cooling tubes located
in vessel l I between the burning stages. Cooling
?uid may be introduced into the cooling tubes
(not shown) through communicating inlets 33
and 34 and withdrawn therefrom through com
. municating outlets 35 and 38. Regenerated con
tact material is ‘withdrawn from vessel ll
rangement of a cyclic conversion system to which
through drain conduit 31 through which ‘it passes
this invention is applied, Figure 2 is an eleva
to conveyor |3./,'_,_ The hot regenerated contact
tional view, partially in section, of a conversion
material is transferred by conveyor l3 to reactor
vessel constructed according to this invention,
Figure 3 is a vertical view, in section, of a modi 30 supply hopper 4|). While the regenerator de
scribed hereinabove is of the multistage type, it
?ed form of gas collecting trough, Figure 4 is a
will be understood that other types of regen
similar view of still another modi?ed form of
erators adapted for regenerating contact mate
gas collecting trough. Figure 5 is an isometric
rials may be employed within the scope of this
view showing the stacking arrangement of
invention. The type of regenerator or revivi?ca
troughs shown in Figure 2, and Figure 6 is a a
tion vessel to be employed will vary depending
graphical representation of certain pressure drop
upon the particular process involved. Any appa
data obtained in connection with the apparatus
ratus adapted to condition the contact material to
of Figure 2. All of these drawings are highly
a state satisfactory for re-use in the particular
diagrammatic in form.
Turning now to Figure 1 there is shown a con 40 conversion process involved is contemplated to
be within the scope of this invention. It should
version vessel [0, a regeneration or revivi?cation
be further understood that this invention is not
vessel II and conveyors l2 and i3 for transfer of
considered as limited to any particular positional
contact material between the conversion and re
arrangement of conversion and ‘regeneration
generation vessels. In operation particle-form
contact material is supplied‘ from hopper 40 45 vessels or to the particular apparatus described
.hereinabove for contact material introduction
through gravity feed leg 4| into the upper section
into the conversion vessel.
of the conversion vessel [0. Used contact material
The improvement of this invention as applied
is withdrawn from the lower end of vessel l0
to the conversion vessel III is shown in Figure 2,
through drain conduit I4. The rate of contact
material ?ow is controlled by valve ii on conduit so wherein I0 is the conversion vessel having solid
inlet 40 at its upper end and outlet I4 at its lower
i4 so that a substantially compact column of con
end. A partition 43 is positioned across the upper
tact material is maintained within the conver
section of the vessel Ill to provide a seal chamber
sion zone. The hydrocarbon charge tovessel i0
44 in the upper end of vessel It. Contact mate
may exist in the gaseous phase or liquid phase
or both. The charge may be heated and com 55 rial passes from seal chamber 44 onto the surface
‘ofthe contact material column 45 in the conver
pletely or partially vaporized in a suitable charge
sion chamber therebelow through uniformly dis
preparation system [6 which may be of conven
tribuated tubes 46 which depend from partition
tional design. Heated charge vapors may be ad
43. The partition 43 and tubes 46 combine to
mitted to the upper section of the conversion zone
through conduit l1 and heated liquid charge may 60 provide a gas distribution space 41 above the con
tact material column in the conversion chamber.
be admitted through conduit l8. Gaseous con
vaporized hydrocarbons may be introduced into
version products are withdrawn, separately of the
the gas space through conduit l1. Liquid hydro
contact material, from the lower section of the
carbons enter through conduit l3 which extends
conversion zone through conduit is through
which it passes to a conventional product recovery 65 across the vessel and is closed on its end within
the vessel. A number of branch pipes such as 48
system 211. An inert seal gas, such as steam or
' and 49 may connect into the conduit it! within
?ue gas may be admitted through conduit 2| into
the chamber. Suitable liquid spray nozzles 10
aseal zone maintained at the upper end of vessel
ill for the purpose of preventing hydrocarbon es
are connected at intervals along conduit l8 and
cape through the gravity feed leg. The rate of
the pipes branching therefrom for spraying of
liquid oil downwardly onto the surface of the
seal gas introduction may be so controlled by
, column 45. Contact material is withdrawn from
means of diaphragm actuated valve 22 and dif
ferential pressure control instrument 23 as to ‘ the bottom of the conversion zone through a.
number of uniformly distributed tubes 55 depend
maintain a seal gas pressure in the seal zone
slightly-above the hydrocarbon pressure in the 75 ing from a horizontal partition 54. The streams
2,458,165
6
from tubes 55 are proportionately combined into
a smaller number of streams ?owing through ori
?ces 56 in still another partition “within the
lower section of vessel l0 and the streams from
ori?ces 56 are proportionately combined into a
single discharge stream ?owing from the con
version vessel in conduit 14. It will be noted
that the ori?ces in partition 51 and the tubes in
partition 54 are arranged in circular rows and
that the number of ori?ces within partition 5,‘!
is less than the number of tubes depending from
partition 54 and that the ori?ces 56 are horizon
thereof than on the other layers of troughs. It
should be understood that the term “trough” as
employed herein in describing and claiming this
invention is employed in a broad sense as cover
ing both angle irons of the type shown in Figure
- 2 and trough constructions such as are shown in
Figures 3 and 4 and troughs of other practical
cross-sectional shapes. It should also be under
‘ stood that the term “ori?ces” is used herein in
a generic sense as covering simple holes such as
at 8| in Figure 3 or the chimney-type of ori?ce
shown at 6| and at 83 in Figures 2 and 4 respec
tally staggered with respect to the tubes 55. By
the gradual proportionate combination of streams
into a single discharge stream as described here
inabove uniform withdrawal of contact material
from all portions of the cross-sectional area of
the conversion vessel is insured. The number
tively.
In Figure 5 there is shown an isometric view
of two layers of stacked angle irons such as are
shown in the apparatus of Figure 2. Like ele
ments in Figures 2 and 5 bear, like numerals.
Turning again to Figure 2, there is provided
of rows of partitions with ori?ces or depending
above the top layer of ori?ce containing angle
tubes employed depends, of course, on the hori ii iron troughs a layer of similar angle irons 82 in
which no ori?ces are provided. The angle irons
zontal cross-sectional area of the vessel involved.
62 serve to prevent ?ow of solid particles through
While for vessels of circular cross-sectional
shape, the tubes in each partition may be con
the ori?ces in the layer of angle irons covered
by angle-‘iron 62.
veniently arranged as concentric circular rows of
Below the lowermost layer of angle irons 60
tubes. On the other hand, for a vessel of rec
there is provided a row of spaced gable-roofed
tangular cross-sectional shape the tubes in each
partition may be conveniently arranged in,
troughs 65 running across the vessel transverse
spaced apart parallel rows of tubes extending
across the vessel.
.
Within the lower section of vessel It! there
is positioned an arrangement of ba?les which
to the angle irons immediately thereabove.
Chimney-type ori?ces 66 are provided in the
gable roofs of troughs 65 to communicate them
with the lowermost layer of angle irons. The
comprises a vertical series of superimposed lay
ori?ces 66 are as large as or preferably larger
ers of inverted troughs which in Figure 2 are
than vthose in the lowermost layer of angle irons.
Flanged nozzles 61 are provided along the vessel
in the shape of angle irons 60 placed one above
the other in a criss-cross manner.
The angle -
irons 60 in any given layer are spaced horizon
tally apart and extend in parallel horizontally
across the vessel in a direction transverse to those
angle irons in adjoining layers. Along the heel
of each angle iron there are provided a series of .
ori?ces 6| so positioned that in any angle iron
the ori?ces are covered by angle irons crossing
thereabove. It has been found preferable for
the ori?ces to be so arranged that in any angle
iron the ori?ces are below the closed part of the .
angle iron crossing thereabove, rather than di
rectly below an ori?ce in the angle iron above.
In order to prevent leakage of solid particles
through the edge of the ori?ces in the angle
irons 60, it has been found desirable to construct 50
the ori?ces in the form of small chimneys as‘
shown in Figure 1. These chimneys may extend
a short distance above the heel of the angle iron
if desired. It will be noted that the size of the
ori?ces 6! increase in stepwise fashion for the
successive layers of angle irons in a downward
direction. The two lowermost layers of angle
irons are provided along their bases with verti
cal skirts 63. All angle irons are provided with
end plates 64 to prevent entrance of solid par_
ticles under the ends of the angle irons.
While the form shown in Figure 2 is a preferred
form of the invention ?at topped inverted chan
nels such as trough 80 in Figure 3 may be substi
tuted for angle iron 60. In the case of ?at topped
channels simple ori?ces 8| may be provided in
stead of the chimney-type ori?ces 6| of Figure 2.
A preferred form of trough construction is shown
shell adjacent opposite ends of the troughs 65.
Flanged sleeves 68 of approximately the same
shape as troughs 65 are provided to slide through
nozzles 61 and under the opposite ends of troughs
65. The sleeves are connected to nozzles 61 by
?anges 69 so that they serve both as supports
for troughs 65 and as passages for ?ow of gas
from under the troughs 65 out into the header
boxes 10 which enclose the nozzles 61 and open
sleeves 68. Gas outlet conduits ‘H are connected
into header boxes ‘ID.
The above described arrangement is such that
there is provided in the lower section of the
vessel ID a substantially continuous tortuous
solid-particle-free gas ?ow passage which is in
gas ?ow communication with the contact material
column at a series of vertical levels and which
is in gas flow communication with gas outlet
conduits positioned outside of vessel I0,
In operation of the apparatus shown in Fig
ure 2 contact material enters the seal chamber
44 through conduit 48 and passes from the bot
tom of the seal chamber through tubes 46 onto
the surface of the contact material column 45
in the conversion chamber. The contact mate
rial ?ows downwardly through the conversion
chamber as a substantially compact column of
gravitating particles and passes through tubes 55
in partition 54 and ori?ces 56 in partition 51 to
‘the drain conduit l4. The rate of solid ?ow is
controlled by means of throttling valve l5.
vaporized hydrocarbon charge enters through
conduit I1 into the distributing space 41 over
the contact material column and then passes
in Figure 4 wherein is shown a sectional view of '
downwardly through the column 45 concurrently
a gable-roofed trough 82 which may be substi
tuted for angle irons 60. A series of chimney
type ori?ces such as 83 are provided along the
gable-roof of trough 82. When such troughs are
employed it is desirable to provide deeper vertical
with the solid ?ow. If part or all of the reactant
charge exists as a liquid, it is introduced through
conduit I8 and sprayed onto the surface of col
umn 45 by' means of spray devices 10. The hy-x
drocarbon reactant is converted under suitable
skirts on the troughs of the two lowermost layers
temperature conditions to gaseous hydrocarbon
2,458,165
7
the uppermost layer of angle irons containing
products as it passes downwardly through the
ori?ces should be such as to cause a pressure drop
conversion chamber. The gaseous conversion
due to the downward flow therethrough of the
products upon reaching the uppermost layer of
amount of gas collected under angle irons 52 of
angle irons tend to become disengaged from
the solid column at surfaces formed by the nor CI the uppermost layer, which pressure drop is equal
to that caused by the ?ow of the residual gas not
mal angle of repose of the solid material under
collected under the uppermost layer of angle irons
the angle irons. A small portion of the gaseous
through that vertical portion of the solid column
products become disengaged at the disengaging
lying between the base of angle irons 62 and the
surfaces under the angle irons 62 and then pass
into the gas space provided by these angle irons. 10 base of the angle irons in the next lower‘ layer of
angle irons. The ori?ces in succeeding layers of
.The remainder of the gaseous products pass
angle irons should be similarly proportioned so
downwardly through the solid column between
as to create a pressure drop due to the gas flow
the spaced angle irons, a portion of the gas
therethrough which will balance that through
being disengaged from the column and collected
under the angle irons at each row thereof. The
gas collected under any given row of angle irons
the solid column between layers.
Since as the
passes downwardly through the chimney-type or
i?ces in the angle irons therebelow to Join the
gas collected under the latter angle irons. Thus
through the ori?ces gradually accumulates and
becomes greater and since the amount of gas
?owing through the column at corresponding
the gas collected under all rows of angle irons
levels gradually decreases, the size of the ori?ces
6| in successive downward layers must gradually
gas works downwardly, the amount of gas ?owing
is gradually combined so that the stream of gas
passing from the lowermost row of angle irons
through ori?ces 66 to the outlet troughs 65 com
prises most of the gaseous hydrocarbon product
increase. The increase in ori?ce size is of course
limited to that maximum size which will still be
except for a small amount of gas which passes
some cases, by the time the lowermost rows of
down through the column between troughs 65 and
is collected under troughs 65. The total gaseous
product collected under the angle irons then
passes through sleeves 68 to manifold boxes 10
from which it is withdrawn through conduits ‘H.
angle irons is reached, the ori?ce size required is
greater than the maximum allowable. In order
to provide the proper pressure drop balance in
such cases, vertical skirts are provided along the
An inert purge gas such as steam or line gas
in order to increase the height of column and
thereby increase the pressure drop due‘ to gas flow
may be introduced through conduit 24 to the
space below partition 54. The purge gas passes
upwardly through tubes 55 and the bed of con
tact material between partition 54 and troughs
65 and is ?nally collected under troughs 65 along
with the gaseous hydrocarbon product. An in
covered by the base of the angle thereabove. In
base of the angle irons in these lowermost layers
through the solid column between these layers.
In this manner the desired pressure drop balance
may be obtained with a much smaller increase in
ori?ce size in the lowermost layers of angle irons
than wouldotherwise be required. In some cases
with such construction two successive layers hav~
introduced through conduit 2| into seal zone
ing the same ori?ce size but different heights may
44 at a rate suf?cient to maintain a higher gase 40 occur. While in general it has been found desir
ous pressure in zone 44 than in the space 41
able to provide vertical skirts on the two lower
of the conversion chamber. In this manner es
most layers of angle irons, skirts may be provided
cape of gaseous hydrocarbons through the con
on more than the two lowermost layers of angle
tact material feed leg 40 is prevented.
irons if desired and even on certain of the inter
By the above described method and apparatus 45 mediately positioned layers of angle irons. It will
there is provided in the lower section of the con
be understandable from the above that while in
version vessel a total amount of gas-solid disen
general, the size of the ori?ces increase to ‘some
gaging surface area which is far in excess of
extent with each successive layer of angle irons
the horizontal cross-sectional area of the column
in a downward direction, on some occasions the
of contact material above the ba?ling. It is there 50 increase in ori?ce size may occur only in groups
fore possible by the described method to pass gas
of layers rather than for each successive layer.
downwardly through the column in the con
For example, in a given application the ori?ce
version zone at a rate which would be su?icient to
diameters beginning with the top layer and work
entrain the contact material and interrupt the
ing ‘down might be 0.0, 0.4", 0.5" 0.6" 0.7" 0.7",
solid column ?ow, if the gas ?ow were upward, 55 0.8", 0.8", 0.9" 1.0" and so on. It should be
and still effect an upward disengagement of
understood that the expressions “in stepwise
gas from the solid column in the lower section
fashion” or "stepwise" are employed in the claims
of the conversion zone without sub~tantial en
in the broad sense as covering both a change in
trainment of solid particles and without inter
ori?ce size or in flow restriction for every succes
ruption of the solid column ?ow. In order to 60 sive layer of angle irons and as covering a change
accomplish the proper gas-solid disengagement
in ori?ce size or in ?ow restriction for groups of
and in order to prevent "boiling” of the contact
layers of angle irons with change in position of
material column and particle entrainment under
the layer in a downward direction as described
the uppermost rows of angle iron it is of great
hereinabove.
importance that the disengaging conditions be
The exact dimensions and the number of layers
maintained substantially uniformunder all the
of the ba?ie structure described hereinabove is
dependent upon the particular hydrocarbon re
angle irons in all the vertically spaced layers
thereof. It has been found that this result may
action, reactant rate, contact material and pres
be accomplished by proper proportioning of the
sure and temperature conditions involved of the
size of the ori?ces in the successive rows or layers ' 70 particular application to which the invention is
of angle irons. Broadly speaking this has been
applied. Moreover the number of layers of angle
found to involve the provision of ori?ces in the
irons is to some extent dependent upon the dimen
sions and spacing of the angle irons employed.
angle irons which increase in size in a stepwise
In general, angle irons measuring from about one
fashion for successive layers of angle irons in a
downward direction. The size of the orifices in 75 inch to six inches across the base may be em
ert seal gas such as steam or ?ue gas may be
2,459,105
v10
gas rates through the same model containing a
bed of the contact material but not containing
between two to four inches across the base. The
any angle irons, and the ordinate represents, for
sides of the angle irons should form a slope with
the same corresponding gas rates, the ratio of
the horizontal of at least about 40° and prefer
the‘ experimentally determined pressure drop
ably of the order of 60° or greater. The angle
through the bed containing the layers of closed
irons should be so spaced in each layer as to
angle irons to the pressure drop for the same
leave a passage for contact material ?ow there
gas rate through the angle free bed.‘ The ori?ces
between measuring at least about ?ve times and
in the angle irons were closed in the experiment
preferably ten times as wide as the largest par
ticle of the contact material. The number of 10 to. insure passage of all gas charged through
the bed. In‘Figure 6', two curves are given, one
layers of angle irons should be su?icient to pro
for spherical gel type catalyst having an average
vide a-total gas-solid disengaging-area which will
ployed. Preferably the angle irons should measure
diameter of about 0.10 inch and the other for
pelletted catalyst having an average diameter of
substantially entrain the solidpartlcles. The gas 15 about 0.10 inch. Having calculated the pressure
drop due to gas ?ow through the bed between
velocity which will entrain and boil solid particles
successive layers of angle irons the ori?ce size
may be determined by calculation from published
for the angle irons in any given layer to balance
equations and data or it may be determined by
the corresponding pressure drop in the contact
simple routine experiments using the particular
contact material and gas that are involved in 20 material bed may be calculated by meansof the
simple ori?ce equation:
the process application under consideration. In
limit the linear velocity of the gas at the dis- ,
engaging surfaces below that which will boil or
general it has been found for catalytic cracking
conversion operations that at least about 4 layers
of angle irons should be used.
The rate of decrease in ori?ce size from layer
to layer of angle irons is dependent upon the par
ticular angle iron size and spacing and upon the
particular contact material and upon the number
-i
A CKIZQH
where His the pressure drop in the bed across
the angle iron in feet of gas ?owing, Q is the
quantity of gas ?owing through the ori?ce in
cubic feet per second, g is the acceleration due to
gravity=32.2 feet per second, per second A is the
of layers of angle irons involved.
The number of layers of angle irons and the. 30 area of the ori?ce in square feet and C isv the
ori?ce coeillcient. The'value of C should be de
proper sizing of the ori?ces to be employed may
termined experimentally. A value of 0.78 for C
be determined in the manner now to be described.
has been found satisfactory for the chimney
Once having settled upon the total rate of flow
type ori?ces.
of gaseous hydrocarbon products and upon the
As an example of the application of the above
diameter of the conversion vessel for a speci?c 35
calculations, in a process involving disengagement
application, then the amount of disengaging
surface area required may be calculated in the ' of a gaseous hydrocarbon product of about 90
molecular weight at a temperature of 875° F. and
manner described hereinabove. The amount of
pressure of 5#/in. Gauge from a particle form
disengaging surface provided by each angle iron
may be determined by multiplying the length of 40 catalyst of 45 lbs. per cu. ft. density and 0.12 inch
average diameter, it was determined that the
the two converging lines drawn downwardly from
linear rate of gas ?ow at the disengaging surfaces
opposite sides of the base of the angle iron at an
to avoid entrainment and boiling of the solids
angle of about 30 degrees by the length of the
should be about 2 feet per second maximum. The
angle iron. Then having selected a suitable angle
iron spacing, the total number of layers of the 45 angle iron arrangement described in connection
with Figure 6 was employed. On the basis of this
angle irons to provide the‘ required disengaging
arrangement it was found that a gas disengaging
area may be easily calculated. Then since an
rate of about 125 cubic feet per minute per square
equal amount of gas is to be collected under each
foot of vessel cross-sectional area was possible.
layer of angle irons the total amount of gas Q
to be collected per unit of time under any layer 50 It was calculated that 12'layers of angle irons
would provide su?lcient disengaging surface for
of angle irons may be readily determined by
the total gas ?ow. The ori?ce diameter in inches
dividing the total rate of gaseous reactant with
for successive layers of angle irons beginning
drawal by the number of layers of angle irons.
with the top layer were calculated to be as fol
The rate of gas flow through the column or
through the passage provided by the angle irons 55 lows: no ports in top layer, 0.268", 0.395", 0.505",
0.605", 0.710", 0.824", 0.943", 1.078", 1.250",
at any level is then ?xed. For example, if there
1.250", 1.625”. The angle irons in the two lower
are twelve layers of angles, the quantity/of gas
most layers were provided with a skirt measuring
?owing through the ori?ces in the ?fth layer
% inch in height along their bases.
from the top is 4Q and the quantity ?owing
It has been found that in general for hydro‘;
through the solid column at the same level must 60
carbon conversion operations, the total horizontal
be 8Q. The next step is to determine the pres
cross-sectional area of the ori?ces in the lower
sure drop due to gas flow through the column be
most layer of angle irons should be at least 2
tween each set of two layers of angle irons. This
times and preferably from 2 to 50 times that
pressure dropmay be approximately calculated
by known methods and on the basis of published 65 of the ori?ces in the uppermost‘ layer of angle
irons which contain ori?ces.
data and equations. Preferably it may be deter
The method and apparatus of‘ this invention
mined experimentally in a small model employing
may be employed in a wide variety of processes
closed angle irons of-the same size and spacing
involving contact of gas with a column of particle
of those to be employed in the conversion vessel.
In Figure 6 there is shown graphically the data 70 form solid material. The invention is particu
larly applicable to catalytic processes for the
obtained experimentally in such a small model
cracking conversion of liquid or vaporous hydro
employing angle irons measuring 25/8" across the
carbon charges or both. In general such hydro
base and 1.97" in height spaced side by side in
carbon conversion operations are conducted under
each layer on 2%" centers. In Figure 6 the
abscissa represents the pressure drop for various 75 temperatures within the range about 800° F. to
2,458,165
a
-‘ i100° lit, the higher temperatures being employed
for liquid charging stocks. Low pressures of the
order of 5 to 30 pounds per square inch are gen
erally employed in the conversion zone for crack
ing conversions. The oil charge space velocity
may vary from about 0.3 to 10.0 volumes of oil
(measured as liquid at 60° F.) per hour per volume
of catalyst column within the reaction zone. The
catalyst to oil throughput ratio may vary within
the range about 1 to 20 parts of catalyst per part
from said column into said passages at all of said
series of vertically spaced levels, causing the gas
collected at any level in said passages to flow
downwardly to Join gas'collected at lower levels
in said passages, subjecting the downward gas
?ow in saidpassages to a stepwise decrease in
restriction in a downward direction so as to insure
the collecting of gas into said passages from said
column at a substantially uniform rate at all of
of oil by weight. In general the reactant charge
is preheated to a temperature of the order of
. 600° F.-900° F. and all or part of the heat required
for the conversion may be carried into the con
version zone in the catalyst.
It should be understood that the speci?c exam
ples of apparatus dimensions and of operating
12
said column at a‘ series of vertically spaced levels,
collecting said gaseous hydrocarbon products
said vertically spaced levels and withdrawing
from said conversion zone at a level near the lower
extremities of said passages as at least one con
I ?ned stream the combined gas collected in said
passages from all of said levels.
3. A method for conversion of ?uid hydro
conditions and the examples of application of
this invention given he'reinabove are intended as
carbons in the presence of a particle-form con
tact mass material which comprises: passing said
illustrative and should not be construed as limit 20 particle-form contact material at suitable tem
peratures for said conversion downwardly
ing the scope of this invention except as it may
be limited by the following claims.
through a con?ned conversion zone as a sub
I claim:
1. A method for conversion of ?uid hydrocar
bons in the presence of a particle-form contact
mass material which comprises: passing said par
stantially compact column of downwardly gravi
tating solid particles, introducing a ?uid hydro
ticle-form contact material at suitable tempera
tures for said conversion downwardly through a
con?ned conversion zone as a substantially com
pact column of downwardly gravitating solid par
ticles, introducing a ?uid hydrocarbon charge
into said conversion zone and passing it down
wardly within said column to effect conversion
of said hydrocarbon charge to gaseous hydrocar
bon products, baii‘ling the solid particle ?ow in
the lower portion of said column to form a con
tinuous tortuous solid-free passage for gas-?ow
through a vertical section of said column, said
passage being in free gas-?ow communication
with said column at a plurality of gas-solid dis
engaging surfaces at a series of vertical levels
within the lower section of said column, collect
ing said gaseous hydrocarbon products from said
column into said passage for gas-?ow at all of
said disengaging surfaces at said series of ver
tical levels, causing the gas collected into said ‘
passage at any level to ?ow downwardly to join
the gas streams collected at lower levels, sub
jecting said gas ?owing downwardly in said pas
sage for gas-?ow to a stepwise decrease in ?ow
restriction as it moves downwardly through said
series of vertical levels so as to provide substan
tially uniform disengagement of gas from
column at all of said disengaging surfaces at
series of vertical levels, and withdrawing
combined stream of gas from all of said
said
said
the
dis
carbon charge into said conversion zone and
passing it downwardly within said column to ef
-fect conversion of said hydrocarbon charge to
gaseous hydrocarbon products, baiiling the solid
particle ?ow in the lower portion of said column
to form a plurality of substantially continuous,
tortuous particle-free passages for gas-?ow
through a vertical portion of said column, said
passages being in gas-?ow communication along
a plurality of disengaging surfaces at a plurality
a: L: of vertically spaced levels with the portion of the
column at said levels which is not occupied by
said gas-?ow passages, collecting gas from said
column at all of said surfaces at said vertically
- spaced levels, causing the gas collected at any
in
level to flow in a general downward direction in
said’ tortuous passages to Join gas collected at
other levels. e?ecting a stepwise reduction in the
resistance to gas-?ow through said passages such
as to cause a stepwise decrease in the pressure
drop due to gas-?ow between any of said levels in
a downward direction, and withdrawing the com
bined gas collected from all of said levels from
the lower extremities of said passages as at least
one con?ned stream.
4. A method for conversion of ?uid hydrocar
bons in the presence of a particle-form solid con
tact material comprising: maintaining a sub
stantially compact column of downwardly» moving
particle-form contact material within a con?ned
conversion zone, replenishing said column at‘ its
upper end with fresh contact material at a suit
able conversion temperature, withdrawingused
contact material from the lower end of said :col
engaging surfaces from said conversion zone.
umn, introducing a heated ?uid hydrocarbon
2. A method for conversion of ?uid hydrocar
bons in the presence of a particle-form contact 60 charge into the upper section of said conversion
zone and passing it downwardly within said col
mass material which comprises: passing said par
umn to effect its conversion to gaseous hydrocar
ticle-form-contact material at suitable tempera
bon products, lba?ling the solid ?ow in the lower
tures for said conversion downwardly through a
section of said column at a plurality of levels to
con?ned conversion zone as a substantially com
form
a plurality of spaced gas collecting zones
pact column of downwardly gravitating solid par 65
from which direct solid ?ow is excluded at a
ticles, introducing a ?uid hydrocarbon charge
series of vertical levels within the lower section
into said conversion zone and passing it down
of said column, collecting, said gaseous products
wardly within said column to effect conversion
from said column in said gas collecting zones at
o_f said hydrocarbon charge to gaseous hydrocar
all of said levels, passing the gas collected in said
bon products, baiiling the solid particle ?ow in 70 collecting zones at any level downwardly as con
the lower portion of said column to form a plu
?ned solid excluded streams to the collecting
rality of substantially continuous, tortuous par
zones next below so as to accomplish the gradual
ticle-free passages for gas-?ow through a vertical
:combining of gas collected at said series of levels,
‘portion of said column near its lower end, said
subjecting the gas ?owing downwardly between
passages ‘permitting gas entrance thereinto from 75 collecting zones to ?ow restriction which de
2,458,165
13
creases in stepwise fashion from level to level of
collecting zones ‘in a downward direction in such
a manner as to accomplish substantially uniform
collection of gas from said column at all of said
14
apart and extending horizontally across said ves
sel in a direction‘ transverse to troughs in ad
joining layers and the uppermost layer being
positioned at a level within the lower section of
said vessel, a series of ori?ces along the troughs
in all layers excepting the uppermost and said
orifices being so located that in any trough they.
zones.
_
X
will be directly below the closed part of the next
5. An apparatus for conversion of ?uid hydro
carbons in the presence of a moving mass of
above trough crossing thereover, said ori?ces
particle-form contact material which apparatus 10 being equal in size in they troughs in any given
comprises: a substantially upright conversion
layer and increasing in size stepwise for succeed
Vessel, means to introduce contact material to the
ing layers in downward direction and said ori
upper section thereof, means to withdraw contact
?ces in the lowermost layer of troughs providing
levels and withdrawing the combined gas as con
fined streams from the lowermost collecting
material from the lower section thereof, means to
a total horizontal cross-sectional area at least
introduce a ?uid hydrocarbon charge into the 15 equal to 2 times the area provided in the row
upper section of said vessel, ba?ie means within
of troughs next below the uppermost layer, at
a lower portion of said vessel, said bailie means
least one inverted trough of substantially great
comprising layers of inverted troughs, the upper
er height than said ?rst named troughs posi
most layer being positioned within the lower sec
tioned below and communicating with said
tion of said vessel, the troughs in each layer being 20 troughs in said lowermost layer, and conduit
spaced apart and extending horizontally across
means to withdraw gas from ‘said last named
said vessel in a direction transverse to those in
the adjoining layers, each of said troughs, except
ing those in the top layer, having a series of
ori?ces along its roof, said ori?ces being so located 25
that in any trough each ori?ce is covered by a
trough in the layer above, the size of the ori?ces
in the troughs in said layers increasing in step
trough.
8. An apparatus for conversion of ?uid hydro
carbons in the presence of a moving mass of
particle-form contact material which apparatus
comprises: a substantially upright conversion
vessel, means to introduce contact material to the
upper section thereof, means to withdraw con
wise fashion with the position of the trough in a
tact material from the lower section thereof,
downward direction, and means to withdraw gas
means to introduce a ?uid hydrocarbon charge
30
from under only the lowermost layer of troughs
into the upper section of said vessel, ba?le means
to a location outside of said vessel.
within a lower portion of said vessel, said baffle
6. An apparatus for conversion of ?uid hydro
means comprising layers of inverted troughs,
carbons in the presence of a moving mass of
the troughs in each layer being spaced apart
particle-form contact material which apparatus
and _ extending horizontally across said vessel
35
comprises: a substantially upright conversion
in a direction transverse to those in the ad
vessel, means to introduce contact material to
joining layers and the uppermost layer being
the upper section thereof, means to withdraw
positioned at a level within the'lower section of
contact material from the lower section there
said vessel, each of said troughs, except those
of, means to introduce a ?uid hydrocarbon charge 40 in the top layer, having a series of ori?ces along
into the upper section of said vessel, ba?le means
its roof, said ori ces being so located that in any
within only a lower portion of said vessel, said
trough each ori ce is covered by a trough in the
ba?ie means comprising criss-crossed layers of in
layer above, the size of the ori?ces in the troughs
verted troughs, the troughs in each layer being
spaced apart and extending horizontally across
said vessel in a direction transverse to those in
the adjoining layers and the uppermost layer be
ing positioned at a level within the lower section
of said vessel, a series of ori?ces along the
in said layers increasing in stepwise fashion with
the position of the trough in a downward direc
tion, a row of spaced inverted troughs of substan
tially greater height and Width than said,first
named troughs positioned within said vessel be
low the lowermost layer of said ?rst named
troughs in each layer excepting the uppermost 50 troughs, and communicating with said troughs
layer and said ori?ces being so located that in
in said lowermost layer through ori?ces in the
any trough they will be covered by troughs in
roofs of said last named troughs, and duct means
the layer next above, said ori?ces increasing
to withdraw gas only from under said last named
stepwise in size with downward position of the
troughs.
_
layers of troughs and the total horizontal cross 65
9. An apparatus for conversion of ?uid hydro
sectional area of the ori?ces in the lowermost row
carbons in the presence of a moving mass of
of said troughs being within the range of 2 to 50
particle-form contact material which apparatus
times that provided by the ori?ces in the row of
comprises: a substantially upright conversion
troughs next below the uppermost layer ahd
vessel, means to introduce contact material to
means to withdraw gas from only the lowermost 60 the upper section thereof, means to withdraw
layer of troughs to a location outside of said‘
contact material from the lower section thereof,
vessel.
means to introduce a ?uid hydrocarbon charge,
_ 7. An apparatus for conversion of ?uid hydro
into the upper section of said vessel, ba?le means
carbons in the presence of a moving mass of
within only a lower portion of said vessel, said
particle-form contact material which apparatus 65 ba?le means comprising superimposed layers of
comprises: a substantially upright conversion
angle irons positioned with their angles opening
vessel, means to introduce contact material to
downwardly, the angle irons of each layer being
the upper section thereof, means to withdraw
' spaced horizontally and being tranverse those of
contact material from the lower section thereof,
adjoining layers, the angle irons in the upper
means to introduce a ?uid hydrocarbon charge 70 most layer being closed along their heels and
into the upper section of said vessel, baii‘le means
being positioned within the lower section of said
within a lower portion of said vessel, said ba?le
Vessel and the angle irons in each succeeding
means comprising at least 4 superposed layers of
layer having a series of orifices along its heel be
criss-cross inverted troughs, the troughs in any
ing so located that in any angle iron they are
given layer being parallel and horizontally spaced 75 covered by angle irons in the layer next above,
9,468,165
l6
said ori?ces in said layers of angle irons increas
ing in size in stepwise fashion for succeeding
layers in downward direction, and members de
?ning a passage for gas withdrawal from under
the angle irons in the lowermost layer thereof to
a location outside of said vessel, remaining layers
of angle irons communicating with said location
outside said vessel only through the ori?ces in
said lowermost layer.
a
-
>
10. An apparatus for conversion of ?uid hydro
s
-
vessel, means to introduce contact material to the
upper section thereof, means to withdraw contact
material from the lower section thereof, means
to introduce a'?uid hydrocarbon charge into the
upper section of said vessel, bailie means within
a lower portion of said vessel, said ba?e means
comprising superimposed rows of angle irons
positioned with their angles opening downward-'
ly, the angle irons in each row being horizontally
spaced apart and extending horizontally across
carbons in the presence of a moving mass of
said vessel in a direction transverse to those in
particle-form contact material which apparatus
comprises: a substantially upright conversion
next adjacent rows, the uppermost row of angle
irons being positioned at a level within the'lower
section of said vessel above said contact material
vessel, means to introduce contact material to the
upper section thereof, means to withdraw con 15 withdrawal means, a series of ori?ces along the
tact material from the lower section thereof,
means to introduce a ?uid hydrocarbon charge
into the upper section of said vessel, baiile means
within only a lower portion of said vessel, said
uppermost row thereof so positioned that in any
means communicating with the space under said
troughs for gas withdrawal from said troughs.
11. An apparatus for conversion of ?uid hydro
upper section of said vessel, bafile means within a
a lower portion of said vessel, said baiile means
heel of all angle irons in all rows excepting the
angle iron the ori?ces are covered by the angle
iron crossing thereover, said ori?ces being of in
baille means comprising superimposed layers of 20 creasing size in a stepwise fashion for succeed
angle irons positioned with their angles opening
ingly lower rows of angle irons so that the total
downwardly, the angle irons of each layer being
horizontal cross-sectional area of the ori?ces in
spaced horizontally and being transverse those of
the lowermost row of angle irons is within the
adjoining layers, the angle irons in the upper
range 2 to 50 times the area of the ori?ces in
most layer being positioned at a level within the 25 the row next below the uppermost row, vertical
lower section of said vessel and being closed along
skirts connected along the bases of at least the
their heels and the angle irons in each succeed- '
two lowermost rows of angle irons to increase the
ing layer having a series of ori?ces along its heel
height of said rows, an external conduit for
being so located that in any angle iron they will
transfer of gaseous products, and passage de?ning I
be directly below the closed part of the next 30 means communicating only the lowermost row of
above angle iron crossing thereover, said ori?ces
angle irons with said external conduit.
in the angle irons of any given layer being equal
13. An apparatus for conversion of ?uid hydro
in size and the ori?ces increasing in size in step
carbons in the presence of a moving mass of
wise fashion for succeeding layers in a downward
particle-form contact material which apparatus
direction, a plurality of gable-roofed troughs of 35 comprises: a substantially upright conversion
substantially larger size than said an'gle irons
vessel, means to introduce contact material to the
positioned'directly below the lowermost layer of
upper section thereof, means to withdraw contact
angle irons and communicating with said angle
material from the lower section thereof, means
irons through ori?ces in their roofs, and duct
to introduce a ?uid hydrocarbon charge into the
carbons in the presence of a moving mass of
comprising at least 4 superimposed horizontal
rows of angle irons positioned with their angles
opening downwardly, the angle irons in each row
particle-form contact material which apparatus
comprises: a substantially upright conversion 45 being horizontally spaced apart and extending
vessel, means to introduce contact material to the
upper section thereof, means to withdraw contact
material from the lower section thereof, means
to introduce a ?uid hydrocarbon charge into the
upper section of said vessel,.bailie means begin 50
ning and extending downwardly within only a
lower section of said vessel, said baiile means
comprising superimposed rows of angle irons posi
horizontally across said vessel in a direction trans
verse to those in next adjacent rows, the upper
most row of angle irons being positioned at a
level within the lower half of said vessel, a series
of ori?ces along the heels of all- angle irons in
all rows excepting the uppermost row thereof so
positioned that in any angle iron the ori?ces are.
below the closed part of the angle iron crossing
tioned with their angles opening downwardly,
thereover, said ori?ces increasingly substantially
the angle irons in each row being horizontally 55 progressively and uniformly in size for succeed-'
spaced apart and extending horizontally across
ing rows of angle irons in a downward direction
said vessel in a direction transverse to those in
next adjacent rows, a series of ori?ces along the
heels of all angle irons in all rows excepting the
uppermost rowthereof so positioned that in any
and the total ori?ce area in the lowermost row
of angle irons being at least 2 times that in the
row next below the uppermost ‘row of angle irons,
60 vertical skirts connected along the bases of all
angle iron the ori?ces are covered ‘by the angle
angle irons in at least the two lowermost rows
iron crossing thereover, said ori?ces being of
to increase the height of the angle iron members,
increasing size in a stepwise fashion for succeed
a header for receiving gaseous products outside
ingly lower rows of angle iron, vertical skirts
of said vessel and members communicating only
connected along the bases of all angle irons in at 65 the lowermost row of angle irons with said header.
least the two lowermost rows to increase the
‘ 14. A method for conversion of ?uid hydro
height ‘of the angle iron members, a reaction
carbons in the presence of a particle-form solid
product withdrawal conduit outside of said ves
contact material comprising: maintaining a sub
sel, and passage de?ning members communicat
stantially compact column of downwardly mov
ing only the angle irons in the lowermost layer 70 ing particle-form contact material within a con
with said withdrawal conduit.
12. An apparatus for conversion of ?uid hydro
?ned conversion zone, replenishing said column
at its upper end with fresh contact material at a
carbons in the presence of a moving mass of
suitable conversion temperature, withdrawing
,particle-form contact material which apparatus
used contact material from the lower end of said
comprises: a substantially upright conversion 75 column, introducing a heated ?uid hydrocarbon
1?
2,458,165
charge into the upper section of said conversion
zone and passing it downwardly within said col
umn to effect its conversion to gaseous hydro
carbon products, ba?ling the solid ?ow in the
lower» section of said column at a plurality of
levels to form a plurality of spaced gas collecting
18
a
cause a pressure drop due to gas ?ow in said
:1
zones from which direct solid ?ow is excluded at
a series of vertical levels within the lower section
of said column, collecting said gaseous products
passage substantia?y equal to that of downward
gas flow through the column of contact material
between the same twoylevels, and withdrawing
the combined collected gaseous products as at
least one con?ned stream from the lowermost
collecting zones.
HERBERT K. HOLM.
from said column in said gas collecting zones at 10
REFERENCES CITED
all of said levels, passing the gas collected in
The
following
references are of record in the
said collecting zones at any level downwardly as
tile of this patent:
con?ned solid excluded streams to the collect
UNITED STATES PATENTS
ing zones next below so as to accomplish the
gradual combining of gas collected at said series 15 Number
Name
> Date
of levels, restricting the downward gas ?ow be
tween each of said vertical series of collecting
zones in stepwise decreasing amount with down
ward position of collecting zones, the amount of
?ow restriction between the collecting zones at 20
any two of said series of levels being such as to
469,849
1,587,582
Borgarelli ________ __ Mar. 1, 1892
Galloway ________ -_ June 8, 1926
2,331,433
Simpson et a1. ___>___ Oct. 12, 1943
2,418,672
2,423,013
Sinclair et a1 _______ __ Apr. 8, 1947
Evans __________ __ June 24, 1947
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