Fluid mixing apparatus and method

A compact mixing apparatus includes a housing and at least one motionless, although possibly vibrated, mixing element in the housing. The mixing element divides into plural streams fluid-like material flowing therethrough, at least twice relatively abruptly changes the flow direction of such streams and preferably imparts rotational momentum to the streams. A chamber in the housing permits generally turbulent mixing of such streams after they exit the mixing element. In accordance with the method of the invention fluid-like material delivered to a housing is divided into plural streams which have their flow directions changed at least twice, and the streams possibly also are rotated and are then combined in a relatively turbulent manner to form a well-mixed output. Moreover, a combustion engine system is disclosed using such a mixing apparatus to mix fuel with a supplemental fluid, with the combined material being delivered to such engine for combustion.

BACKGROUND OF THE INVENTION 
The invention generally relates to mixing devices and particularly to those 
known as motionless mixers. The invention also relates to methods of 
mixing fluid-like materials and, in a particular embodiment, to a 
combustion engine system capable of producing a mechanical output in 
response to combustion of a combined fluid-like material input thereto. 
The mixing of relatively stationary fluids, for example in a mixing 
container, may be carried out by a moving mixing blade or the like. Such 
movable mixers, however, are bulky, require large power inputs, and are 
difficult to adapt to use in fluid systems in which continuously flowing 
fluids are to be mixed. However, a number of so-called motionless mixers 
are available for the purpose, as disclosed, for example, in U.S. Pat. 
Nos. 3,923,288; 3,583,678 and 3,860,217. In the former patent a plurality 
of flow dispersing or interrupting elements are placed in a relatively 
long tubular housing to form a mixing matrix for turbulently mixing the 
fluid flowing therethrough. In the latter two patents the main flow stream 
through a relatively long tubular housing is divided into several discrete 
flow streams that flow through separate passageways. The positional 
relationship of the divided flow streams where they initially divide and 
where they exit the dividing elements is altered for enhanced variation in 
the interfacial surface contact between flow streams. Where the flow 
streams exit such a dividing element, they mix turbulently and then enter 
a further dividing element until finally the mixed fluid exits the device. 
The known theory of stratification for interfacial surface generators, such 
as the one disclosed in U.S. Pat. No. 3,583,678, follows the equation 
S=N(X).sup.Y ; where S is the stratification or number of individual 
strata produced by the mixing apparatus; N is the number of components 
being mixed; X is the number of streams produced by each dividing element 
of the mixing device; and Y is the number of dividing elements in the 
housing of the mixing apparatus. The larger the value S, the larger the 
number of strata produced by the mixing device and, accordingly, the more 
homogeneous is the mixture produced thereby. 
The foregoing and other examples of motionless mixers for continuously 
flowing fluids are relatively large and cumbersome, relatively expensive, 
and in many cases unsatisfactory for producing long-lasting, homogeneous 
mixtures. 
As used herein the term fluid of fluid-like means a material that is 
capable of flowing, such as, for example, a liquid, a gas, or even a solid 
that has satisfactory flow characteristics or is carried in a fluidic 
carrier; for example, such materials may be a pigment for mixing in a 
paint, a polymer being mixed to facilitate polymerization, etc. The 
present invention, however, although capable of and intended to effect 
mixing of various media, will be described in detail below with reference 
to the mixing of water and gasoline to form an emulsion that is consumed 
in a combustion engine. 
In the past, one technique for combining water and gasoline or other 
combustible fuel to be burned in a combustion engine, such as in an 
aircraft engine, employed the direct injecting of small quantities of 
water into the fuel. However, as fas as is known by the applicant, no 
substantial mixing of the water and fuel was effected. 
In present day combustion engines such as an internal combustion engine 
used in an automobile, it is common to burn an overly rich mixture, i.e. 
larger than the optimum fuel air mixture for complete combustion, so there 
is some unburned vapor remaining in the products exhausted from a 
cylinder. That unburned vapor provides an important function of cooling 
the exhaust products to avoid excessive damaging heat at the exhaust valve 
and/or rest of th exhaust system. For fuel economy, though, it would be 
desirable to burn an effectively leaner mixture having a lower percentage 
of fuel. 
SUMMARY OF THE INVENTION 
In accordance with the present invention a mixing apparatus mixes a 
fluid-like material comprised of a plurality of fluids by dividing such 
material into plural streams, changing the direction of each stream at 
least twice, preferably imparting rotational momentum to the streams, and 
then allowing the streams to mix generally turbulently. The present 
invention relates to both an apparatus and a method for effecting the 
foregoing. In the preferred embodiment each individually formed stream 
makes an initial right angle bend where it enters the mixing element of 
the mixing apparatus and is bent an additional right angle to exit the 
mixing element, itself in the housing of the apparatus, where it then 
turbulently engages the other streams in a mixing area. The streams also 
perferably are rotated and/or twisted at least once to impart rotational 
inertia thereto. Such disruption of each individual stream is obtained in 
the mixing element with effective mixing of the individual streams. The 
streams then mix well with other streams in the relatively open mixing 
chamber between adjacent mixing elements, for example. The several forms 
of mixing element, each including plural cooperative parts to form several 
flow paths, perform the mixing operation efficiently in a relatively small 
space. Moreover, the thorough mixing effected by the mixing apparatus 
appreciably reduces the possibility of stratification of the inlet streams 
intended for mixing. 
In accordance with another aspect of the invention the mixing apparatus is 
employed in a combustion engine stream to produce a relatively 
long-lasting (generally greater than one minute) homogeneous emulsion of a 
fuel, such as gasoline, with water and/or other additives. The mixing 
apparatus produces such mixture upstream of the engine combustion chamber. 
The combustion engine produces a mechanical output in response to 
combustion of such mixture with a number of unexpected results being 
obtained, as described further below. It is believed that with the 
addition of from about 1/2% by volume to about 30% by volume of water to 
fuel and preferably from about 1/2% to about 7% by volume of water to 
fuel, the resulting mixture burned in the engine can be leaner than in the 
past allowing for a greater percentage of the fuel to be burned than in 
the past while the water vapor produced provides the cooling effect for 
the exhaust products mentioned above. The combination of the mixing 
apparatus with a combustion engine, a fuel supply, and a supplemental 
fluid supply, such as water, has a greater fuel efficiency and uniformity 
of engine operation than was previously attainable. 
In accordance with still another aspect of the invention, one or more of 
the parts forming the mixing elements may be formed of an additive 
material that degrades into the fluid flowing therethrough. Therefore, as 
the fluid flows through the mixing element, the degrading of such material 
provides a controlled dispersion of such additive into the fluid. 
Another aspect of the invention involves the applying of vibration or other 
mechanical motion to the mixing elements further to enhance the mixing 
efficiency of the mixing apparatus. Such vibrations may be of relatively 
low frequency of, for example, several hertz through the ultrasonic 
frequency range. Such vibrating in the ultrasonic range also may desirably 
effect a heating of the fluid material, which may be employed, for 
example, to enhance the combustion efficiency and/or to avoid freezing 
along the fuel flow lines, at the carburetor, etc. of an engine. Such 
vibration also may be employed to enhance the controlled degrading and 
delivery of additives described above. 
Thermal energy also may be delivered, in accordance with the invention, to 
the fluid flowing through the mixing apparatus via a conventional electric 
resistance heating mechanism or by conventional microwave heating 
apparatus for enhanced combustion efficiency, for avoiding freezing, for 
expediting reactions, etc. 
With the foregoing in mind, it is a primary object of the invention to 
provide a mixing apparatus and method that are improved in the noted 
respects. 
Another object is to provide a combustion engine system that is improved in 
the mentioned respects. 
An additional object is to improve the efficiency of a mixing apparatus, 
particularly one for continuous mixing of flowing fluids, for example by 
reducing the size, cost, and/or power requirements for the same, by 
improving the operational effectiveness, and the like. 
A further object is to facilitate the controlled addition of additives to 
fluids. 
Still another object is to mix plural continuously flowing fluids. 
Still an additional object is to obtain a homogeneous and longlasting 
emulsion of plural fluids, such as of water and fuel, such as gasoline, 
and especially of immiscible fluids. 
Still a further object is to increase the stratification of a continuously 
flowing fluid material to enhance the homogeneous nature thereof including 
both chemical homogeneity as well as thermal homogeneity. 
These and other objects and advantages of the present invention will become 
more apparent as the following description proceeds. 
To the accomplishment of the foregoing and related ends, the invention, 
then, comprises the features hereinafter fully described in the 
specification and particularly pointed out in the claims, the following 
description and the annexed drawings setting forth in detail certain 
illustrative embodiments of the invention, these being indicative, 
however, of but several of the various ways in which the principles of the 
invention may be employed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now in detail to the drawings, wherein the same reference numeral 
designates like parts in several figures, a mixing apparatus 10 is 
illustrated in FIG. 1 as part of a combustion engine system 11 for a 
vehicle represented by the dotted outline 12. The mixing apparatus 10 has 
an inlet 13 into which metered quantities of plural fluids, in this case 
fuel, such as gasoline, from a fuel supply tank 14, and water from a water 
supply tank 15, are delivered by a fluid metering device 16, such as 
conventional fluid flow controlling devices including, for example, the 
vehicle fuel pump, not shown. It is the purpose of the mixing apparatus 
thoroughly to mix the fluid material received at the inlet 13. The 
thoroughly mixed material exits the mixing apparatus 10 at its outlet 17 
as a homogeneous mixture, for example in the form of a well dispersed, 
relatively long-lasting emulsion of fuel and water. The effluent from 
outlet 17 is combined in a carburetor 18 with air from its supply 19, and 
that combination is provided to a combusjtion engine 20, such as a 
conventional internal combustion engine of an automobile. Although 
illustrated in connection with a combustion engine that ordinarily 
requires a carburetor 18, the mixing apparatus 10 of the invention 
similarly may be employed in an engine that uses full injection 
principles. In the engine 20 the inlet fluid material is burned, and the 
engine produces a mechanical output that is coupled, for example, via the 
drive train to the vehicle wheels, as represented at 21, to move the 
vehicle. The mechanical output from the engine 20 also is coupled to the 
vehicle battery 22, which performs the usual electrical functions in a 
vehicle. 
Moreover, the battery 22 may be coupled, as shown, to a conventional 
vibratory generator 23, such as one of relatively low frequency type, say 
on the order of several hertz, even to a relatively high frequency 
ultrasonic type. The generator 23 effects vibratory motion in the mixing 
apparatus 10 further to enhance the mixing efficiency thereof. Moreover, a 
heater 24, such as a conventional electrical heater, a microwave energy 
generating heating apparatus, or the like, may be powered from the battery 
22 via a connection, not shown, to heat the fluid flowing through the 
mixing apparatus 10. Such heating may be used, on the one hand, to enhance 
the combustion efficiency of the engine 20 by pre-heating the fluid 
supplied thereto and/or, on the other hand, to avoid freezing of the 
relatively high freezing-point water flowing through the mixing apparatus 
10 and passing particularly through the carburetor 18. 
The combination of water with the fuel in the combustion engine system 11 
improves the fuel efficiency thereof. The water in the fuel provides the 
cooling function previously mentioned. The mixing apparatus assures a 
homogeneous mixture or emulsion of the fuel and water for uniformity of 
air combination therewith at the carburetor 18 and similarly uniform 
engine operation. This effective operation is in contrast to the past 
direct water injection where water was injected directly into the cylinder 
and too much water could cause mis-operation of the engine. 
The mixing apparatus 10 may be used for mixing fluids other than fuel and 
water. For example, in the combustion engine system 11, other additives, 
such as methanol also may be mixed with the water and fuel further to 
avoid freezing and to enhance the dispersing of water in the fuel. Wetting 
agents and the like also may be included in the mixing fluids. The mixing 
apparatus 10, moreover, may be used in many other systems in which one or 
more fluids or fluid-like materials generally continuously flowing are to 
be mixed. 
Turning now to FIG. 2, the mixing apparatus 10, shown enlarged, includes a 
housing 30 through which the fluid-like material flows and a plurality of 
mixing elements 31 in close tolerance position relationship with respect 
to the internal side wall 32 of the housing to assure that the majority 
and preferably all of the fluid flowing through the housing passes through 
the respective mixing elements. The mixing elements are mounted in the 
housing 30 on a connecting rod 33, which is secured to the housing 30 by 
one or more sealed nut or like connections 34 with an external rod portion 
35 coupled to the vibrating generator 23. The mixing elements 31 have 
central openings through which the connecting rod 33 passes and are 
mounted on the latter separated by respective spacers 36 in fixedly 
secured position by nuts 37 engaging the illustrated threads on the 
connecting rod. The rod 33 also represents generally an illustrative net 
axial direction in which fluid flows to pass through the housing. The 
mixing apparatus 10, moreover, importantly includes between respective 
mixing elements 31 and between the last mixing element closest the outlet 
17 respective relatively open mixing chambers 38 in which the individual 
flow streams formed by the respective mixing elements may generally 
turbulently shear and otherwise mix to form ultimately the relatively 
long-lasting, homogeneous mixture effluent exiting the outlet 17 of the 
housing 30. The axial depth along rod 33 of the chambers 38 may be varied, 
as desired; generally the larger the flow rate of fluid through the mixing 
device 10, the larger should be the depth of the chambers 38. The heater 
24 is illustrated in FIG. 2 as an electric resistance heating wire 
preferably of the electrically insulated type to avoid direct electrical 
contact with the housing 30, with a switch 39 for completing an electrical 
circuit between the battery 22 and the heater 24 to supply heat as 
aforesaid. The large surface area interfacial contact between the fluid 
material flowing through the mixing apparatus 10 and the various rigid 
surfaces of the latter and the turbulence with which the fluid engages 
such surfaces assures an extremely efficient thermal energy transfer 
therebetween. 
Each mixing element 31 is formed of a generally flat plate 40 and a fluted, 
somewhat dished disc 41, as shown in detail in FIGS. 3-6 which illustrate 
in connection with FIGS. 1 and 2 the most preferred embodiment or best 
mode of the invention. Preferably the plate 40 and disc 41 are formed of 
copper or of stainless steel, such as No. 316 stainless steel for good 
fatigue resistance, especially in those instances that the mixing elements 
are to be vibrated ultrasonically. However, other materials also may be 
used, such as, for example, plastics, plastic-like materials, other metal 
materials, etc. The plate 40 preferably is flat and has a circular 
circumference for close tolerance positioning against the interior 
generally cylindrical wall 32 of the housing 30. The plate 40 also has an 
array of outlet holes 42, eight of them being employed in the illustrated 
embodiment, for the purpose of discharging individual flow streams formed 
by the mixing element 31 into a mixing chamber 38 of the mixing apparatus 
10. A central opening 43 through the plate 40 accommodates the connecting 
rod 33. 
The disc 41 also is of generally circular circumferential configuration, as 
the plate 40, to fit closely against the internal cylindrical wall 32 of 
the housing 30, although if that wall were other than of cylindrical 
configuration, the external circumferences of the plate and disc could be 
correspondingly altered. The disc 41 is dished in a manner generally 
apparent from the isometric or perspective showing in FIG. 3. A central 
opening 44 accommodates the connecting rod 33 and is located generally at 
the apex of the dish or cone of the disc 41 such that when the latter is 
positioned with its exterior circumference is generally flat abutment with 
the plate 40, the opening 44 is spaced away from the plate. A plurality, 
in the illustrated embodiment eight, of tapered triangular cross-section, 
radially curving flutes 45 are formed in the disc 41, each having a 
relatively sharp edge 46 raised away from the plate 40 and tapering down 
to an apex 47 relatively proximate the plate 40 where the external surface 
48 of the disc rises to a next sharp edge 46. Each flute 45, as 
illustrated, has a radius of curvature approximately equal to one-half the 
cross-sectional radius of the disc 41 and, acordingly, angularly curves 
approximately 180.degree.. 
When assembled, the plate 40 and disc 41 are placed into abutment with each 
other with the central openings 43, 44 aligned relative to a common 
longitudinal axis 50 along which the connecting rod 33 extends. Several 
such mixing elements may be placed on the connecting rod 33, relatively 
separated by spacers 36, and the total combination, then, may be secured 
on the rod by the nuts 37. Although only three mixing elements are shown 
in FIG. 2, it is contemplated that approximately eight such mixing 
elements would be employed in the mixing apparatus 10, although more or 
fewer mixing elements may be used, as desired. The interior surface 51 of 
the disc 41, as is seen in FIG. 6, interior surface referring to the 
surface of disc 41 facing the plate 40, is formed similarly, but 
oppositely relative to the exterior surface 48 thereof, which is seen in 
FIG. 5. The interior surface 51 is generally dished, although the 
effectively raised walls or edges 52 thereof in cooperation with the plate 
40 form isolated fluted channels generally represented at 53 along which 
fluid flows in isolated streams, for example, as shown by representative 
flow stream lines 54, 55. A plurality, in the illustrated embodiment 
eight, of inlet holes 56 through the disc 41 provide entry of fluid onto 
the respective fluted channels 53. As shown, four of the inlet holes are 
located at approximately equal radial distances from the longitudinal axis 
50 for communication with alternate fluted channels 53. Similarly, the 
four remaining inlet holes 56 are located at a different equal radial 
distance from the longitudinal axis 50 for communication with the 
remaining alternate fluted channels 53. Preferably the inlet holes 56 are 
located in the exterior surface 48 of the respective flutes 45 relatively 
proximate the respective apexes 47 to assure maximum fluid collection by 
the inlet holes, thereby avoiding any stagnation or collection of fluid 
without passage of the same through the inlet holes into the mixing 
element 31. Moreover, the outlet holes 42 through the plate 40 are 
oriented similarly, but oppositely relative to the inlet holes 56 of the 
disc 41 so that fluid entering, for example, the inlet hole 56A and 
flowing down through the fluted channel 53A formed between the disc 41 and 
plate 40 will exit the outlet hole 42A into a chamber 38, as is 
illustrated by the stream line 54 in FIGS. 3 and 6, for example. 
Similarly, the stream line 55 enters the outer radial inlet hole 56B, 
flows radially inwardly, i.e. in an opposite radial direction relative to 
that of the stream line 54 in the fluted channel 53A, through fluted 
channel 53B and upwardly out through the radially inwardly located outlet 
hole 42B of plate 40. Thus, it will be appreciated that the two flow 
streams flowing through adjacent fluted channels 53 will, as they exit 
respective outlet holes 42 of plate 40, have generally opposite rotational 
vectors and, accordingly, oppositely directed rotational inertia or 
rotational momentum that enhances the shear between respective streams and 
the turbulent mixing of them in respective chambers 38. 
From the foregoing, it will be appreciated that each mixing element 31 
initially divides the fluid input thereto into eight separate streams such 
as those represented by the stream lines 54, 55. Looking at the flow 
stream line 54, for example, that stream initially makes a 90.degree. bend 
as the fluid passes through the inlet hole 56A, each bend effecting a 
mixing turbulence in the stream and in some instances a criss-crossing of 
the respective boundary layers thereof for maximum mixing homogeneity, and 
commences its flow down through the fluted channel 53A. The tapering of 
the fluted channel 53A, moreover, effects a twisting action of the stream 
54 about the flow axis of such stream. Furthermore, the radial curvature 
of the fluted channel 53A bends the flow axis of the stream 54 flowing 
therealong to impart to that stream a rotational inertia or rotational 
momentum as it exits the plate 40 through the outlet hole 42A. Too, a 
right angle bend is effected in the flow stream as it leaves the channel 
53A and passes through the outlet hole 42A. 
The multiple direction changes, the bending of the flow axis by about 
90.degree., and the twisting of the flow stream all contribute to the 
thorough mixing in the individual flow streams passing through the mixing 
element 31, and the oppositely directed flow streams exiting from plate 
40, then, turbulently mix in the respective chambers 38 to assure 
effective mixing operation. Since the direction changes occur normally 
without substantial backflow or reverse direction flow of the streams 
immediately back upstream in the housing 30, the back pressure in the 
mixing apparatus 10 is minimized. Furthermore, between adjacent fluted 
channels 53 in the dished surface 51 of the plate 41, there may be space 
provided for communication between adjacent, but oppositely directed or 
counter-rotating, flow streams. Such communication effects an interfacial 
shearing as the two oppositely directed streams pass, still further 
enhancing the mixing effectiveness. The mixing element 31 also radially 
displaces fluid whereby fluid that is generally near the rod 33 upstream 
of the mixing element is moved outward near the wall 32 at the downstream 
end and vice versa further enhancing the mixing effectiveness of the 
apparatus 10. Thus, the four inner streams formed by the mixing element 31 
are radially transposed with respect to the four outer streams. 
During operation of the mixing apparatus 10, fluid is delivered from a 
supply generally indicated at 59 to the inlet 13 where it enters the lower 
chamber 60 of the housing 30. The first mixing element 31 divides the 
fluid flowing from chamber 60 into eight generally laminarly flowing 
streams that undergo multiple directional changes and ultimately enter the 
first mixing chamber 38 where generally turbulent mixing occurs. From the 
first chamber 38, the fluid again is divided by the next mixing element 31 
into eight streams again, and so on until ultimately a substantially 
homogeneous mixture effluent is provided the outlet 17 of the mixing 
apparatus 10. In the preferred embodiment, two fluids are mixed, namely 
fuel and water, from eight to about twelve mixing elements are employed, 
and about eight streams are formed in each mixing element. With that data 
the above stratification S equation can be solved to find that the 
theoretical size of the respective strata in the final mixing chamber 38 
just prior to the outlet 17 is on the order of about 1/2 angstrom, there 
being about 260 million layers, and such theoretical dimension is smaller 
than that of a water molecule. Therefore, an extremely effective mixing of 
the water with the fuel is assured. 
Additionally, the many layers formed in the mixing apparatus 10 assures 
excellent skin contact with the various surfaces of the mixing elements 
31, which may be vibrated by the generator 23 and connecting rod 34, to 
assure good coupling of the vibration energy to the fluid. 
Also, the edges 46 of the flutes 45 of the disc 41 effect a shearing action 
of fluid engaging the same further to divide or break up the individual 
flow streams in the respective mixing chambers 38, still further 
increasing the mixing efficiency of the mixing apparatus 10. 
In FIG. 7 is illustrated a modified alternate mixing element 61, which may 
be substituted in the mixing apparatus 10 for the respective somewhat 
similar mixing elements 31 described above. The mixing element 61 also 
includes a plate 62 similar to the plate 40 above and a disc 63, which is, 
to an extent, dished or in a hollow truncated conical-like form in the 
manner of the disc 41 described above but in this case is formed with a 
plurality of corrugations to form with the plate 62 a plurality of 
corrugated channels 64. A plurality of inlet holes 65 in the disc 63 are 
formed at respective radial locations in the same manner as the inlet 
holes 56 and a plurality of outlet holes 66 in the plate 62 also are 
similar to the outlet holes 42 above. The plate 62 and disc 63 also have 
respective central openings 67, 68 concentric about a common longitudinal 
axis 69 to receive the connecting rod 33, as above. When assembled, the 
plate 62 and disc 63 are placed into tight engagement and effect a similar 
or equivalent flowing and mixing operation of the streams flowing 
therethrough as above. However, the truly curved sides of the respective 
corrugations and corrugated channels 64 of the disc 63 providing the 
smoothness of the mixing element 61 minimizes back pressure in a mixing 
apparatus; and to that extent the embodiment illustrated in FIG. 7 is 
preferred over the mixing element 31. However, it has been found that the 
disc 41 provides more effective shear between the mixing elements and 
effective twisting of fluid in the mixing elements than the convoluted 
disc 63, so to these extents the mixing element 31 is preferred over the 
mixing element 61. 
Although the mixing apparatus 10 and mixing element 31 are shown in FIGS. 
1, 2 and 3 in position for vertically upward flow of the fluids 
therethrough and the mixing element 61 is similarly illustrated in FIG. 7, 
such parts may be reversed to obtain vertically downward flow of fluids 
therethrough. The disadvantage to the latter in a vehicle system, though, 
would be in the delay that might be encountered when starting the vehicle 
and awaiting sufficient fluid flow to reach the engine. Also, it will be 
appreciated that the mixing element 31 as well as the other mixing 
elements of the invention may divide the flow into more or fewer than 
eight streams. 
Referring now to FIGS. 8 and 9, a further modified or alternate mixing 
element 71, which may be substituted for the above-described purposes in 
the mixing apparatus 10 of FIGS. 1 and 2, for example, to produce 
equivalent mixing function, includes a three-part sandwich of upper and 
lower dished plates 72, 73 and a central disc part 74. The mixing element 
71 has lower tolerance requirements than the other mixing elements hereof, 
therefore is easier to manufacture on a small scale basis, and to that 
extent is preferred. The disc 74 has a central opening 75 circumscribed by 
a generally planar ring-like annulus or shoulder 76. The disc 74 is 
corrugated in a fashion such that rib-like portions 77 extend radially 
from the annulus 76 alternately in respective directions upward and 
downward from the annulus plane, as shown. Between respective ribs 77 are 
generally planar surfaces 78, these being, of course, slightly curved 
enabling them to meet the annulus 76 so that the entire disc 74 may be 
formed out of a single stamped part, for example. Preferably the disc 74 
is stamped from a single circular flat disc to form the convoluted shape 
thereof and has eight such ribs 77, eight planar surfaces 78, and eight 
flow through holes 79 through respective planar surfaces, with alternate 
ones of those openings being punched to form a surrounding ridge 79' 
extending alternately upward or downward relative to the illustration of 
FIG. 8. Plate 72 is dished in a manner to form with alternate upwardly 
directed ribs 77A respective upper fluid chambers, such as the fluid 
chamber 80 that would be formed between the bottom surface of plate 72, 
ribs 77A in the lower right-hand quadrant of the illustrated disc 74, and 
planar surfaces 78A. Similarly, plate 73 is dished upwardly to mate with 
ribs 77B to form four lower fluid chambers, such as the one illustrated at 
81 in the lower central quadrant of the illustrated disc 74 with the 
surfaces 78B. 
The plate 72 includes eight inlet holes 82 therethrough, four of which are 
located relatively close to the center of the plate and four of which are 
radially spaced further outward from the plate center. The radially inward 
inlet holes 82 align with the upwardly punched flow through holes 79 of 
the disc 74 so that fluid passing downwardly through those inlet holes 82 
also passes downwardly through those upwardly punched flow through holes 
79, for example into the flow chamber 81 illustrated with respect to a 
flow stream 83. Such alignment and sandwich-like configuration of the 
mixing element 71 is more clearly seen in FIG. 9. As shown, such flow 
stream 83 will pass under planar surfaces 78B in flow chamber 81 while 
also curling over the upper surface of plate 73 until that flow stream 
ultimately exits through a respective radially outwardly located outlet 
hole 84 in plate 73. It will be understood that as the flow stream 83 
follows that flow path, it will undergo two right angle direction changes, 
will tend to curl or curve in the flow chamber 81 to impart a rotational 
inertia to the flow stream exiting the outlet hole 84 for turbulent mixing 
in a mixing chamber 38 of the mixing apparatus 10 described above with 
reference to FIGS. 1 and 2 above. Flow streams, such as the one 
illustrated at 85, passing through one of the outer radial inlet holes 82 
of plate 72 is directed into an upper flow chamber, such as the flow 
chamber 80 where it also undergoes two right angle changes in direction, a 
change in momentum as it flows down one planar surface 78A and up the next 
while tending to curl or rotate as it ultimately enters through one of the 
downwardly punched flow through holes 79 from which it passes directly 
through one of the inner radial outlet holes 84 of the lower plate 73. 
Thus, as above, the mixing element 71 divides the flow coming in from the 
top thereof into eight flow streams, four of which are moved from radially 
outward positions relative to the center of the mixing device flow through 
upper flow chambers 80 such that they encounter multiple direction changes 
and rotational inertia as well as a repositioning to a radially inward 
portion of the mixing device as they exit through downwardly punched holes 
79 and outlet holes 84, as shown, for example, by the flow stream 85. 
Similarly, the four inner flow streams, such as the flow stream 83, flow 
through the lower flow chambers 81, also undergoing multiple direction 
changes and having imparted thereto a certain amount of rotational inertia 
while they are displaced to radially outward positions in the mixing 
device passing through the plate 73 at the radially outward holes 84 
thereof. Moreover, since the flow streams 83, 85 actually flow in opposite 
directions through their respective flow chambers, the rotational inertia 
imparted to them where they exit the lower plate 73 will generally be in 
opposite directions for enhanced turbulent mixing in the mixing chambers 
38. 
Each of the mixing elements described above, as well as those described 
hereafter, may include at least one part formed of a material, i.e. a 
substrate, that degrades with the flow of fluid through the mixing device 
to provide one or more desired additives in the fluid. In this regard, the 
mixing element 71 with its three-part sandwich construction is preferred. 
The disc 74 may comprise such degradable material, whereas the plates 72, 
73 may comprise non-degradable material. Therefore, the plates 72, 73 will 
provide containment for the disc 74 as it degrades and will assure at 
least some mixing action and separation between respective mixing chambers 
38 even if one such disc 74 fully degrades prematurely. 
A mixing device was constructed generally in accordance with the mixing 
device illustrated at 10 in FIG. 2 including a housing 30, a connecting 
rod 33, a plurality, namely 12, of mixing elements 71 in the form 
illustrated in FIGS. 8 and 9 (instead of the mixing elements 31 shown in 
FIG. 2), a fluid inlet and a fluid outlet, and this mixing device was 
satisfactorily used, as follows. The housing was about 6 inches long and 
cylindrical with a diameter of about 11/2 to 2 inches. Attached to the 
mixing device was a conventional solenoid pulsing device that applied 
vibratory pulses to the connecting rod 33 at a frequency of approximately 
120 hertz. The fluid flowing through the mixing device flowed in a 
downward direction, with the fluid inlet at the top and the fluid output 
at the bottom, and the latter was connected directly to the carburetor of 
a four-cycle, several horsepower, internal combustion engine ordinarily 
used on a snow blower. 
Initially, 200 cc. of regular octane (about 91 average octane) gasoline was 
poured into a holding tank. From the holding tank that gasoline was passed 
through the mixing device directly into the carburetor. The engine was 
started, and it ran for approximately eight minutes at a constant throttle 
setting of about 70%. While the engine was running, it achieved a 
relatively high temperature and a relatively significant amount of visible 
and odorous exhaust was produced. The engine stopped when its fuel supply 
was depleted. 
The condition of the engine sparkplug was examined prior to further 
operation of the engine and the sparkplug found to be fouled. Then, about 
190 cc. of gasoline and about 10 cc. of water, the latter including 
approximately 30% methanol, although the inclusion of methanol is believed 
unnecessary for proper operation of the engine, were poured into one 
container and from such container into the mentioned holding tank. While 
the mixing device was being vibrated at approximately 120 hertz, the 
engine was started from a warm up condition substantially as in the 
above-described prior test. The water, gasoline, and methanol mixture was 
mixed by the mixing device and fed by the force of gravity to the engine 
carburetor. This time the engine ran for approximately twelve and one-half 
minutes until it depleted its fuel mixture supply at the same throttle 
setting as above. During such operation, there was a substantial reduction 
in the exhaust odor, a noticed reduction of about 10 to 15 degrees F. in 
the exhaust temperature stream measured about 3 to 4 inches from the 
engine exhaust port, and a cleaning of the exhaust so that it was nearly 
invisible. Moreover, during such operation the engine clearly appeared to 
run at a faster speed. The sparkplug was examined after the latter test, 
and there was clearly a marked cleaning of the electrode. During the 
latter test one problem was encountered, this being the apparent 
agglomeration of water particles in the mixing apparatus apparently due to 
the stagnating of water at relatively low lying areas of the respective 
flow chambers of the mixing elements 71. Nevertheless, the engine ran 
quite properly without any sputtering or tendency to stall as those 
periodic droplets of BB size were delivered at a rate of approximately one 
every ten seconds, through the carburetor to the engine. 
Thus, in the foregoing test, approximately 2 to 7% by volume of water was 
mixed with gasoline to provide ultimately a substantially increased 
operating efficiency of the engine including, particularly, an unexpected 
increase in the operating time of the engine. Further, it is believed that 
additional amounts of water may be combined with the gasoline to form an 
emulsion having up to about 30% by volume of water as an ingredient. The 
emulsion formed by the mixing apparatus in the above-mentioned test, 
moreover, appeared to hold up for about three minutes, which ordinarily 
would be more than adequate for use in an automobile engine, for example. 
Although the mixing device described above in the test was vibrated the 
mixing devices according to the invention would be useful to mix fluids 
adequately without such vibration, it being appreciated that variations in 
the flow rates, dimensional parameters of the mixing device, number of 
streams formed by and the number of mixing elements, etc. can be varied to 
achieve the desired mixing. 
It will be appreciated that although the size and number of the holes in 
the respective mixing elements disclosed herein; the width, length, depth 
and like parameters of the channels formed in each mixing element; the 
size and number of the mixing elements and spacing therebetween, and so on 
all may affect the mixing accomplished by a mixing device in accordance 
with the invention wherein fluid is divided into plural streams, each has 
its direction changed at least twice, and the streams then are turbulently 
mixed, these parameters may be varied as desired to obtain desired mixing 
results. 
In accordance with the invention, the most preferred embodiment considering 
ease of manufacturing is illustrated in FIGS. 10-13 in which the mixing 
device 10', only a portion of which is illustrated in FIG. 10, is similar 
to the mixing device 10 described above with reference to FIGS. 1 and 2, 
but includes a plurality of modified mixing elements 101. The mixing 
device 10' includes, as before, a housing 30', a connecting rod 33', and a 
plurality of mixing chambers 38' between the respective mixing elements 
101. 
Each of the mixing elements 101 includes a plate 102 and a disc 103, which 
are held firmly in abutment and in a particular alignment fashion, with 
the latter function being obtained, for example, by a conventional keying 
technique, not illustrated. The plate 102 and disc 103 have central 
openings 104, 105, respectively to receive the connecting rod 33', as 
above, and the disc 103 also has a depending annular shoulder 106 on its 
surface facing away from the plate 102. The annular shoulder 106 
circumscribes the opening 105 and provides a spacing function analogous to 
that provided by the spacers 36 described above, namely the provision of 
the mixing chambers 38' between adjacent mixing elements 101 in the mixing 
device 10'. 
Through the plate 102 are eight fluid inlet holes 107, four of which are 
located at a relatively small radial distance from the center of the plate 
and four of which are located radially further from the center thereof. In 
the disc 103, are eight dog-leg-like channels 108, each of which has an 
inlet end 109, which aligns with a respective inlet hole 107 of the plate 
102; a bend 110; an outlet end 111; and an outlet hole 112. Preferably the 
angle of the bend 110 defined between the inlet and outlet ends of each 
channel 108 is more than an acute angle to maintain the laminer flow 
characteristics of the fluid therein and to obtain in effect a cross-flow 
shearing and twisting of the flow stream through a channel as, for 
example, the fluid boundary layer along one side of the inlet end of the 
channel crosses over and confronts, as well as, to an extent, switches 
geometrical positioning with respect to the fluid boundary layer flowing 
along the opposite side of such inlet end at the bend 110. Further, 
preferably each channel has a depth of approximately 1/2 the thickness of 
the disc 103, and, moreover, the distance or depth of each mixing chamber 
38' between adjacent mixing elements 101 is about the same as the channel 
depth. Such proximity of adjacent mixing elements promotes shear in the 
respective mixing chambers 38'. Moreover, preferably the inlet holes 107 
of one mixing element do not align with the outlet holes 112 of the next 
adjacent mixing element to avoid straight-through channeling of fluids 
through the mixing chambers 38'. Accordingly, the fluid in the mixing 
chambers 38' will have to seek its own path to the next mixing element, 
thus obtaining good turbulence and shear in each mixing chamber, reducing 
channeling, and avoiding stagnant areas at which water particles, for 
example, may collect and/or agglomerate. The channels 108 further operate 
to bring a flow stream entering the same from a respectively outer or 
inner radial inlet hole 107 of the plate 102 to the opposite respective 
inner or outer radial position of the outlet holes 112 in the disc 103. 
In operation of the mixing device 10' fluid enters the initial chamber 
thereof and then passes, either downwardly or upwardly, if desired, such 
that one fluid stream divided from the main body of fluid enters an outer 
radial inlet hole 107 and into the inlet end 109 of a channel 108. That 
flowing action effects a flattening of the flow stream. Moreover, the flow 
stream undergoes a right angle bend as it begins its flow down through the 
inlet end of channel 108 toward the bend 110, bends again at the such 
bend, and undergoes another right angle bend at the outlet hole 112 at a 
relatively inner radial position of the disc 103 where that flow stream 
then enters the appropriate mixing chamber 38'. Turbulent mixing occurs in 
the mixing chamber 38', and the fluid therein again divides into plural 
flow streams in the next mixing element 101 or after exiting the last 
mixing element exits the housing 30'. Similarly, a flow stream entering 
one of the inner radial inlet holes 107 of the plate 102 ultimately will 
be brought by a respective channel 108 to a relatively outer radial 
position outlet hole 112 of the disc 103. 
The mixing elements 101 and the mixing device 10' are preferred in view of 
the foregoing and, especially, due to their relative ease of manufacturing 
compared to the more complex discs described above. Moreover, the mixing 
elements 101 assure relatively constant cross-section flow streams and 
facilitate control of the various flow paths to assure that they are all 
substantially equal, thereby preventing the occurrence of a more 
preferential path through the mixing device 10'. If desired, the plate 102 
and/or disc 103 may be formed of molded material and may have an outer 
circumference which is slightly larger than the inner circumference of the 
housing 30' to assure a good seal therewith. The disc 103 may be formed of 
plastic, ceramic materials, metal, or other materials. The disc similarly 
may be formed of those materials, although metal is preferred for the 
strength of the mixing element and to provide electrostatic stabilization, 
if necessary. 
Although the mixing elements 101 are illustrated with eight flow paths 
therethrough, additional channels and inlet holes may be provided in the 
disc 103 and plate 102 respectively. Furthermore, if desired, for example 
to reduce the flow restriction effect of the mixing elements 101, 
additional channels may be formed in the bottom surface of the disc 103, 
the annular shoulder 106 removed, the disc itself thickened, if necessary, 
and an additional plate similar to the plate 102 provided against such 
surface to provide a three-part sandwich mixing element having, for 
example, sixteen or even more flow paths therethrough. 
In FIG. 14 is illustrated an alternate form 121 of the mixing element 101. 
The alternate mixing element 121 includes a plate 122 that is similar to 
the plate 102, except for its generally dished shape, and a disc 123, 
which also is similar to the disc 103 except for the dished shape 
illustrated. The inlet holes 127, channels 128, and outlet holes 132 in 
the disc are all similar in form and function to those described above 
with respect to the mixing element 101. The dished shape of the mixing 
element 121, however, further reduces the possibility of encountering any 
stagnation or places at which water particles may collect and/or 
agglomerate, for such water particles would, at the least, move toward the 
area of lowest potential energy or gravity, e.g. toward the center of the 
mixing element where the connecting rod penetrates the same for pick up by 
respective inlet holes 127. 
Although each of the above-described mixing elements would work in a mixing 
device described with fluid flowing in the preferred described direction, 
it will be appreciated that each also will work with fluid flowing in the 
relatively opposite direction through the mixing element. Moreover, 
although the preferred form of the invention employs eight stacked mixing 
elements in a housing, it will be appreciated that fewer or more mixing 
elements may be employed and fewer or more flow paths through each mixing 
element also may be employed within the spirit and scope of the invention. 
Of course, the dimensional parameters of the various components described 
above may be varied, as desired, to accommodate the particular fluid 
materials to be mixed by the mixing device. For example, relatively 
small-size flow paths may be used for relatively low viscosity materials; 
whereas larger-size parameters may be necessary to accommodate higher 
viscosity materials.