Note: Descriptions are shown in the official language in which they were submitted.
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A wide number of reactors are
known to the art in attempts to maximi7e both
physical and chemical reactions between matter
in different states, that is, gaseous, solid and
liquid or any combination thereof. Most of the
prior reactors for such purposes have been of
a batch type such as kettles and agitated tank
reactors. Continuous reactors have been used
where surface reactions are conducted such as
contactor packed column reactors or turbulent
bed absorber-reactors.
The prior art heterogeneous reactors
have not been as efficient as desired in that
the reactions take a longer time than desired
and in the case of continuous reactors, often
times the slower reactions do not permit
the desired completion of reaction to be
achieved. Another serious disadvantage with
prior continuous heterogeneous reactors has
been problems of plugging when solid state
materials are involved.
It is an ob~ect of the present
invention to provide an apparatus and process
for conducting reactions between reactants
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in differing states which are highly efficient and useful in
a wide variety of applications.
In one particular aspect the present invention provides
a low pressure drop apparatus which may be operated with or
without liquid for promoting heterogeneous chemical and
physical reactions in a gas stream by concurrent movement of
said gas stream and reactant liquids and solids comprising: -
a vertical casing which is substantially liquid and gas
t`ight having a gas inlet in the upper portion;
means in the upper portion of said casing for introduction
of reactant liquids and solids;
a continually converging nozzle within said casing
having an entry at the upper end in communication with said
gas inlet and an outlet at the lower end, said entry being
in substantially closed relation to said casing to avoid :
substantial bypass of said nozzle and having an effective
cross-sectional area of about 2 to about 64 times the effective
cross-sectional area of said outlet and the mean angle of
convergence of said nozzle being about 6 to 20 causing
differential velocities and differential accelerations of
non-compressible liquids and solids and compressible gas;
impingement means below said nozzle outlet to insure
impingement thereon of substantially all particulate matter
entrained in the gas stream passing from said nozzle outlet,
said impingement means being spaced from said outlet a
distance of about 1.3 to about 2.5 times the diameter of
said outlet;
means for removing liquid and particulate matter from
the lower portion of said casing following desired reaction;
and
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means for separately removing the gas from the lower
portion of said casing.
In another particular aspect the present invention provides
a process having pressure drops of less than that characteristic
of a process using a Venturi device for inducing heterogeneous
chemical reactions in gas streams comprising: -
passing a gas stream and solid or liquid reactant into
the upper`portion of a vertical casing;
~ passing the gas stream and solid or liquid at entry
velocities under 2100 feet per minute through a continually
converging nozzle symmetrical with respect to its axis
within the casing and having an entry.in communication with
the gas inlet, the entry of the nozzle having an effective
cross-sectional area of about 2 to about 64 times the effective
cross-sectlonal area of the outlet and the mean an~le of
convergence of the nozzle being about 6 to 20~, differential
.velocities and differential accelerations and decelerations ~-
of non-compressible liquids or solids and compressible gas
substantially only along the axis of the nozzle, causing at
least two states of gas, solids and liquid to contact causing
chemical reaction of reactants in passing through the nozzle;
impinging solids and llquids upon an impingement means
located beneath the nozzle outlet at a distance of about 1.3
to about 2.5 times the diameter of said outlet;
removing the liquid and particulate matter from the
lower portion of the casing; and
separately removing the gas from the lower portion of
the casing.
The above and other objects and features of the invention
will become more apparent from the following description and
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figures showing preferred embodiments wherein:
Fig. 1 shows a cross-sectional view of one embodiment
of an apparatus of this invention using single nozzles in
series;
Fig. 2 shows a cross-sectional view of another embodiment
of an apparatus of this invention using multiple nozzle plates
in series; and
Fig. 3 shows a cross-sectional view of the apparatus of.
-Fi`g. 2 at section 3-3.
Referring to Fig. 1, the heterogeneous reactor is
shown defined by outer casing 10. The cross-sectional shape
of outer casing 10 is
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preferably cylindrical, but may be square,
rectangular, triangular, hexagonal, or other
symmetrical polygon shape, but other geometrical
shapes symmetrical with respect to the axis of
the apparatus are satisfactory, the principal
requirement being that it enclose the apparatus
in generally liquid and gas type relationship
while providing controlled gas flow through the
interior portion. To allow maximum flexibility
in the utilization and maintenance of the
heterogeneous reactor, casing 10 may be
fabricated in sections with the sections having
flanges as shown by 11 and 13 at each end for
rigid coupling to adjacent casing sections
having like flanges 12 and 14. Instead of the
flanges as shown in Fig. 1, any suitable
coupling means may be utilized. To allow for
maximum economy of original fabrication and
installation of larger units the sections may
be welded prior to shipment and erection.
Fig. 1 shows a three stage hPterogeneous reactor.
The heterogeneous reactor is arranged
with its axis vertically having the reactant
solid-liquid-gas inlet in the upper portion.
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The inlet may be in either a vertical or
horizontal position. The reactant flow i9
supplied to the top of casing 10 through the
inlet at a velocity and pressure sufficient to
carry it through the apparatus. The hetero- -
geneous reactor of this invention may be
operated under any positive and negative
pressures suitable for the desired reaction
or evaporation or cooling objective, limited
only by the materials of construction.
Casing velocities can be chosen to optimize
the reactions such as low velocities where
high absorption efficiences are desired to
high velocities where closed loop recycle
~ithout the need for demisting is permitted.
Spray 41 may be ocated in the
central portion of inlet to cylinder 10 and
introduces liquid or solid reactant, adsorbent,
absorbent or coolant in droplet form to
the reactant stream, the droplets being
preferably in the order of about 40 to about
1500 microns in diameter. Larger droplets may
be desired to compensate for evaporation when
evaporative conditions exist if it is desired
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to leave the cone without excessive reduction
of the material. Spray 41 is preferably a
solid cone spray which by itself or in co~bi-
nation with several like it arranged in a
pattern permitting the introduction of droplets
of liquid across the entire cross section of
the pollutant gas stream prior to entry of the
gas stream into cone 21. Different sized
liquid drople~s are desirëd to provide
maximum differential accelerations, deceler-
ations and velocities through the apparatus,
thus increasing reaction rates. It is desired
that the spray pattern extend across the full
area of entrance 25 of nozzle 21 and any
suitable pattern of sprays or multiple sprays
is satisfactory. Spray 41, designed to disperse
solids, may also be used to introduce solid
particles of the above specified sizes to
the reactant stream at the entrance 25 of
nozzle 21.
The reactant containing heterogeneous
solid-liquid-gas stream enters converging nozzle
21 through entry 25. It is preferred that the
entry be round and the nozzle conical, but other
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geometrical shapes symmetrical with respect to
the axis of the apparatus are satisfactory. The
cone ratio, defined as the effective cross-
sectional area of the entry divided by the
effective cross-sectional area of the outlet,
should be about 2 to about 64, about 2 to
about 36 being preferred, with about 2 to about
12 being especially preferred for many low pressure
drop pxocesses. By effective cross sectional area
is meant the area at 90 to the axis of gas flow.
The length of the converging portion of
the nozzle is determined by the angle of convergence
shown as A in Fig. 1 and the nozzle ratio as
defined above. It is preferred that the mean angle
of convergence be about 6 to about 20~, about 8
to about 18 being preferred and about 12 to 16
especially preferred for many low pressure drop
processes. By mean angle of convergence is meant
the angle measured between a straight line drawn
from the entry to the outlet and a vertical line
as shown by A in Fig. 1. The sides of nozzle 21
do not need to be straight, but may be somewhat
convex or concave.
The distance from outlet 24 to the
impingement surface 31 should be about 1.3 to
about 2.5 times the diameter of outlet 24, about
1.6 to about 2.0 being preferred.
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A suitable impingement plate is shown
as 31 in Fig. 1. Impingement plate 31 is of
sufficient size to have substantially all of the
liquid-solid matter from nozzle exit 24 impinge
upon it while affording sufficient area between
the impingement plate and cylinder 10 to allow
passage of the gas around impingement plate
without appreciable pressure drop. While
impingement plate 31 is shown as a flat plate,
a slightly concave plate to facilitate the
passage of gas around the edges and to
facilitate the removal of particulate matter
may be utilized. For reactions not requiring
separation of solid and liquid phas~s from the
gas phase, or mass transfer phenomena such as
associated with evaporative processes such as
take place in the cooIing tower7 an impingement
curface would not be needed as shown below
nozzle 23 in the apparatus of Fig. 1.
Additional sprays may be suitably
located above impingement plate 31 so that the
spray therefrom washes particulate matter off
imp~ngement plate 31 for progress through the
apparatus and discharge at the bottom. Such
,
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sprays may be multiple sprays located around the
periphery of impingement plate 31 or a satisfactory
spray may be located in the central position.
When sufficient fluid is used, the impingement
surface will be the fluid itself and the particu-
late matter will not strike or`adhere to the
impingement plate, but will be entrapped in the
fluid. The essential criteria of the sprays
upon impingement plate 31 is that they provide
sufficient fluid with sufficient force and
direction to keep impingement plate 31
relatively free of particulate matter. The
reactor may also be operated without the
supplemental sprays to clean the impingement
surfaces.
Because of the unitized construction of
the apparatus of this invention, as shown in
Fig. 1, multiple nozzle-impingement means stages
may be readily placed one on top of the other,
resulting in the series of three units as shown
in Fig. 1. One to about 6 of the series connected
stages of noz~les are suitable for many hetero-
geneous reactors for use in this invention.
Preferably 2 to 4 stages are utilized in series.
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Any number of stages of nozzles may be utilized
in series as is found necessary to carry the
chemical or physical reaction to desired
completion. The nozzle stages placed in series
may provide different reaction properties by
the nozzles having different inlet-outlet area
ratios and different angles of convergence and
may employ unitized arrangement if a great
many such nozzle stages are required. The
number of stages is controlled by the difficulty
of reaction of the reactants, and with especially
difficult materials, a greater number of stages
may be necessary. This could also be influenced
by the angles of convergence or effective cross-
sectional area ratios of the nozzles.
Beneath the bottom stage is reservoir
15 for removal of ~he liquid and slurry. Exit
means for the removal of the gas are also
provided as shown in Fig. 1 as conduit 16.
Either within the apparatus or external to the
apparatus it may be preferred to have demister
17 in the clean gas effluent line to remove
fine droplets of liquid remaining in the gas
stream together with any solids or gases
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trapped by such droplets. Again, where closed
loop recycling is involved it may be desired
to eliminate the demisters so that the
droplets in mixture with the gas and solids
may continue reacting until such mixture returns
to the reactor.
The vertical arrangement of the converging
nozzles is particularly advantageous since using
such an apparatus having a demister and a nozzle
ratio of 4 and a nozzle angle of approximately
15~ the pressure drop in one nozzle is 3.5 inches
of water; with two nozzles in series is 5.7 inches
of water; with three nozzles in series is 7.0
inches of water; and with four nozzles in series
is 8.3 inches of water when an inlet velocity
of approximately 2100 feet per minute was used.
Thus, it is seen that the pressure drop of the
vertical series of nozzles is advantageously
less than cumulative. It has been found that the pressure
drop across a two stage heterogeneous reactor, both stages
having an impingement plate of the type shown in Fig. 1 designed
to accommodate approximately 2100 feet per minute inlet
velocity is 0.9 inches of water using a nozzle ratio of 4
and a nozzle angle of approximately 12 when an inlet velocity
of about 380 feet per minute was used in the removal of
sulfur oxides from effluent gases from the combustion of coal.
The second stage, as shown in Fig. 1,
is identical in configuration to the first stage.
It is recognized, however, that the water or
l~quid chemical supplied to both the nozzles
preceeding the cone entrance and the nozzles
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supplying liquid to the impingement surface of
the same stage or of different stages may be
individually controlled. That is, the volumes
may be different and the liquid used may be
different in each instance.
The passing of the liquid, solid and
gaseous reactant in the stream through nozzles
such as 21, promotes intimate contact between the
liquid, solid and gaseous reactant and results in
desired high reaction rates. It is believed the
high reaction efficiency of the heterogeneous
reactor and process is due to differential veloci-
ties and differential acceleration and deceleration
achieved by the combination of non-compressible
matter passing with the compressible gas through
nozzle 21 with the opportunity for relatively
great expansion following exit from nozzle exit 24.
In the reactant containing stream there is a
size range of compressible and non-compressible
matter. Additional particles added to the gas
stream by addition of solids or liquid droplets
are principally non-compressible as desired to
increase the non-compressible component of the
gas stream. Spray 41 may be used to introduce
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a wide selection of-liquid or solid particle
sizes to the gas stream and together with a
relatively wide span of liquid or solid
particle sizes in the inlet gas stream,
promote extremely high collision rates and
high compressible gas rates flowing past the
non-compressible particles and droplets
resulting in very highly efficient reactions.
In order to minimize the height of
the apparatus of my invention as shown in Fig. 1,
I have found that multiple cones may be placed
in each stage as shown in Figs. 2 and 3. The
embodiment as shown in Figs. 2 and 3 show outer
casing 100 which is substantially liquid and gas
tight having gas inlet 118 in the upper portion.
Casing 100 may have flanges as shown by 111 and
113 at each end for coupling to adjacent casing
sections having like flanges 112 and 114.
The upper stage as shown in Figs. 2 and
3 has plate 160 through which gas nozzles 150,
151, 152 and 153 are arranged. Fig. 3 shows the
cross-sectional arrangement of t'ne four nozzles
mounted on plate 160. Any number of gas nozzles
which have the properties as previously set forth,
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are suitable, from about 2 to about 6 being
preferred in a single stage.
In a similar manner to that previously
described, liquid or solid particles may be added
by sprays above the gas nozzle inlets, such as
spray 142 above the inlet 125 to nozzle 150.
The gas stream passes through the
converging nozzles to an impingement surface
beneath the nozzle exits as exemplified by
exit 124 of nozzie 150. As previously described,
the impingement surface may be an impingement
plate shown in Fig. 2 as 131 and may have
liquid sprays to aid washing particulate matter
off the impingement plate as shown~in Fig. 2 as
145 and 146. The impingement plate beneath
multiple nozzles may be a series of separate
plates having a geometry such that a gas flow
passes from each nozzle for impingement upon a
corresponding impingement surface following
which the gas flows freely around that impinge- -
ment surface for passage to the volume beneath
the impingement plate assembly.
Similar to the apparatus shown in Fig. 1
beneath the lowest imp~ngement surface is reservoir
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115 for removal of liquid containing undesired
particulate and/or chemical matter and means
for its removal. Exit means 116 are shown in
Fig. 2 for removal of the gas from below the
lower impingement surface shown as 132. A
demister shown as 117 is preferred when the
apparatus is utilized with liquid sprays to
remove fine droplets of liquid remaining in the
clean gas. The second stage is shown identical
to the first or upper stage.
With the unitized construction of the
apparatus of this invention, multiple units may
readily be placed on top of one another resulting
in a series of two units as shown in Fig. 2.
One to about six of the series connected stages
of multiple nozzles are suitable for an apparatus
of this invention, preferably 2 to 4 nozzle-
impingement means stages are utilized in series.
The unitized arrangement referred to earlier in
Fig. 1 would also apply here. The apparatus and
process of this invention is suitable for
absorption, polymerization, vaporization, adsorption,
stripping, gaseous cooling and condensation reactions.
The process of this invention for inducing
chemical and physical reactions in gas streams
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comprises passing a gas stream and solid or
liquid into the upper portion of a vertical
casing; passing the gas stream and solid or
liquid through a nozzle within the casing and
having an entry in communication with the gas
inlet, the entry of the nozzle having an
effective cross-sectional area of about 2 to
about 64 times the effective cross-sectional
area of the outlet and the mean angle of con-
vergence of the nozzle being about 8 to about
18, the acceleration and deceleration of the
gas stream causing at least two states of gas,
solids and liquids to contact causing chemical
and physical reaction of reactants in passing
through the nozzle; removing the liquid and
solid particulate matter from the lower portion
of the casing; separately removing the gas from
the lower portion of the casing. The liquids-
solids and agglomerates thereof may be impinged
upon an impingement means beneath the nozzle
outlet for separation from the gas stream.
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While in the foregoing spec~fication this
invention has been described in relation to certain
preferred embodiments thereof, and many details have
been set forth for purpose of illustration, it will
be apparent to those skilled in the art that the
invention is susceptible to additional embodiments
and that certain of the details described herein
can be varied considerably without departing from
the basic principles of the invention.
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