US1988743A - Machine for making bituminous emulsion - Google Patents

Description

Jan. 22, i935. L, R, `MacKENZlE '1,988,743

MACHINE FOR MAKING BITUMINoUs EMULsIoN Filed'March 2, 1951 v5 Sheets-sheet 1 Jan.'22, 1935. L. R. MacKENziE 1,988,743

MACHINE FOR MAKING BITUMINOUS EMULSION Fil'ed March 2, 1931 3 Sheets-.Shet 2 Jan. 22, 1935o L. R. MacKENzlE 1,988,743

MACHINE FOR MAKING BITUMlNOS EMLSION i Filed March 2, 1931 3 Sheets-'Sheet 3 @iff ` I li lf JIU l5 which is then inverted to form a secondary intertially conical ooaoting Surfaces are employed, one i '35 ing aliqueous emulsion of a bituminous substance Figure 3 iS a Similar VieW Showing a further no Patented Jan.. 122,` 1935 l UNITED STATES PATENT OFFICE MACHINE FOR MAKING BITUM'INOUS EMULSION Leon R.- MacKenzie, Des Moines, Iowa, assignor to L. R. MacKenzie Incorporated, Tulsa, Okla., a corporation of Delaware Application March 2, 1931, serial No. l519417 11 claims. (01.134-1) The purpose and aim of this invention is to Figure 2 is a longitudinal section of the same. provide a machine for making a stablellqueous As shown particularly in this view, this form of emulsion of a bituminous substance either liquid the machine employs two substantially cylindrior semi-liquid or capable of becoming liquid, such cal surfaces, one being arranged for rotation withas asphalt, and particularly a machine adapted in the other and being slightly tapered to formf 5 to the process covered by my co-pending applian elongated converging annular space, one cation, led October 30, 1930, Serial No. 492,169, member being adjustable longitudinally with renow Patent Number 1,795,226. lation to the other so as to provide meansfor This machine is peculiarly adapted for carryregulating the spacing of the surfaces and the l0 ing out a continuous process of succession of resultant neness of the emulsion Drodueed- 10 steps beginning with the introduction of hot liq- Figure 3 is 'a transverse section on the line 3 3 ueous bitumen and an emulsifying agent, at propof Figure 2- er temperatures, to a closed chamber and form- Figure 4iS a vlongitudinal Section illustrating e ing a primary bitumen external phase emulsion dilerent form of machine in which tWO Substannel phase emulsion, The Secondary emulsion is conical member being arranged for rotation withthen subjected to a stretching, sub-dividing and inthe other. This form of the machine also emrolling operation betweenelongated and convergbodies o jacket for live Steam. whereby the ining relatively moving surfaces, whereby the coarse terior of the machine muy be heated. emulsion is changed to one of nner form, 'and a, Figure 5 is a cross section on the line 5 5 of 2o variation o! sizes of particles is produced. There- Figure 4- ater, the fine tertiary emulsion is subjected to Figure 6 iS a CroSS Seotion 0n the line 6-6 0f centrifugal action to remove air bubbles and to Figure e. reduce it from e. fcamy tc e more fluid state, as Figure '1 is a longitudinal section illustrating e well as to increase the thoroughness of the mixing Portion 0f emaehine Somewhat Similar to that 2li andthe completeness of dispersion. Shown in Figure 4, but modified With respect to l Included within the scope of this invention is the mixing chamber or zone of formation of the the object of adjustability of one of the coacting' primary emulsion, this machine being equipped surfaces relative to the other for the purpose of with an interrupted spiral blade mounted for changing the spacing between said surfaces and rotation in the elongated chamber, the initial to thereby regulating the size of the particles of portion of Said blade noting es e wiping and bitumen in the resulting emulsion. equalizing member and the longer terminal por- Another object of the invention is to provide tion acting eS an egitating and emulsion odvenoan improved construction for a machine for malcing means.

such as asphalt, which emulsion will be suflicientmodified form of machine having a different form ly stable so that it can be handled, stored, and of o Spiral rotary member Which Combines the used under ordinary conditions. functions of an agitating member and a grinding With these and other objects in View my invenmember in coaction with the walls of a chamber 4U tion consists in the construction, arrangement which graduulllr iIlCreeSeS in diameterand combination of the various parts of my de- Figure 9 is a cross section of a machine of still vice, whereby the objects contemplated are atfurther modified form in which the rotary memtained, ashereinafter more fully set forth, pointed ber is eccentrically mounted within the chamber out in my claims, and illustrated in the accom for producing a converging eiiectv of the space panying drawings. Although the invention is between the coasting surfaces. This machine also 45 susceptible of a variety of embodiments it is unembodies a different means for producing centrifnecessary to fully describe and illustrate al1 posugal action with respect to the completed emul- 4sible forms in order to give a-full understanding of sion.

the invention both from its structural and func- Figure 10 is a perspective view illustrating a tional standpolnts. Accordingly, l have illustratmodified form of frusto-conical arbor grinding 50 Y edseveralpreferred and'desirable embodiments member. This member is of the same general of the invention in the Aaccompanying drawings, type as the corresponding member of the machine in which:- n illustrated in Figure 4, but is modified with re- Figure 1 is a perspective view of a machine emspect to a series of tapering grooves extending bodyingone form of my invention. Vlongitudinally of its surface. f 555 Figure 11 is a detail longitudinal section of portion of the arbor grinding member illustra in Figure 10, and the surface with which it coacts. This view illustrates particularly the fact that the 'tapering groove formed in the surface of the arbor grinding member affords a different degree of convergence relative to the coactlng surface, than is afforded by the general surface .of the arbor grinding member with respect to said coacting surface.

Various kinds and forms of emulsions may be made with machines embodying the present invention, and with bitumen of any desired state of hardness or ductility. The emulsions may be made with any reasonable and practical relative volumes of'bitumen and the emulsifying agent, which will hereinafter be referred to as emulsiner. A further advantage resides in the speed and economy of production which may be had. l

I have found that a very important characteristic of the machine is embodied in the use of two closely approximated surfaces of elongated character or extent, at least one of which is rotated relative to the other, and which preferably converge toward the outlet of the space between them. These surfaces, which may or may not be serrated or otherwise deformed or roughened, act to stretch, sub-divide and roll the particles of bitumen into progressively finer form and also act to increase the dissemination, dispersion and diffusion of the bituminous particles through the emulsifier and thus produce the desired type of emulsion.

'I'he spaced surfaces may be of dilerent shapes and formations and may be embodied in machines of varied constructions. In the accompanying drawings I have illustrated a number of different types of machines as examples of different embodiments of my invention.

In the construction according to Figures l, 2 and 3, I have employed the numeral 10 to designate a suitable base upon which is mounted or formed a suitable casing member 12 which preferably is substantially cylindrical.

One end of the casing is formed by a separate plate 14 which is tted snugly to the member 12 and secured in place in any suitable manner, as by cap screws 16.

The rigid end wall of the casing member 12 is formedwith a tubular extension 18 of less diameter than and communicating with the interior of the casing.

The tubular extension 18 is interiorly threaded and a sleeve 20 is adjustably mounted therein and extends within the inner casing member 12. The sleeve 20 is open at its inner end and is formed at its outer end with an angular wrenchreceiving or capportion 22 by means of which it may be adjusted within the tubular extension 18 and the wall of the casing.

The tubular extension 18 preferably is split longitudinally on one side by means of a slot or kerf 24 opening to its outer end and is formed with a pair of ears 26 and 28 on opposite sides of the outer end of said kerf.

A clamping lever 30 is provided and is formed with a right-angled stem 32 turnably mounted in one of the ears such as 28 and having threaded engagement with the other of said ears such as 26. When the clamping lever 30 is turned in one direction manually it permits the ears 26 and 28 to spread apart slightly so that the sleeve 20 may gagement of its stem 32 causes the ear 26 to be drawn toward the ear 28 so that the split tubular member is clamped tightly upon the sleeve 20 and rotary movement of the latter member is prevented.

Rotatably mounted in the casing 12 and extendingwithin and substantially throughout the length of the sleeve 20 is an arbor 34. The arbor 34 is formed with a reduced journalv 36 which is mounted for rotation in a bearing 38 in the removable end member 14 ofthe casing.

A prime mover such as an electric motor 40 is mounted on the base l0 and its armature shaft 42 is operatively connected by a coupling sleeve 44 with the journal 36 of the arbor.

'I'he interior wall of the sleeve 20 and the exterior surface of the arbor 34 provide the two elongated coacting surfaces which constitute a distinctive feature of my invention. As here shown, the interior surface of the sleeve 20 is truly cylindrical while the outer surface of the arbor 34 is slightly tapered. In other words, the arbor 34 fits quite closely within the sleeve 20, but is spaced a slightly greater distance therefrom at its outer than its inner end, thus providing a converging annular space between these members.

This arrangement, whereby a slightly tapered member is mounted within and slightly spaced from a member having an internal cylindrical surface,.also permits of' some adjustment of the relative spacing of the two Lsurfaces by adjusting the members axially. This adjustment is accomplished, as previously indicated, by the threaded mounting of the sleeve 20 within the casing 12 and its-.extension 18.and the adjustment when made is maintained by means of the clamping lever 30.

'I'he arbor 34 is formed at its inner end with a peripheral ange 46 which rotates in substantial contact with the inner face of the casing end member 14 and is normally spaced somewhat from the inner end of the sleeve 20.

IThe arbor 34 is formed at its outer end wit an outwardly opening recess or cavity 48, which preferably is of substantially frusto-conical shape and formed with a long and gradual taper; An inlet tube 50 is threadedly mounted through the outer end of the sleeve 20 and has its inner end projecting a substantial distance within the recess 48 of the arbor. v

The outer end of the inlet tube 50 is suitably connected, as by means of a packing gland 52, with a Y 54, the two branches of which are connected, as by means of packing glands 56 and 58, with feed pipes 60 and 62 respectively.

The two substances to be acted upon, namely the liqueous bitumen and the emulsier, are supplied to the machine through the feed pipes 60 and 62 from suitable containers, which are not shown in connection with this particular form.

of machine although they are shown in the machine illustrated in Figure 5. These containers may be in the nature of pressure tanks, whereby the substances may be introduced to the machine under pressure and they should also be equipped with means for preheating the substances separately to the desired temperatures.

In lieu of or in addition to pressure at the supply end, either by pressure in the supply tanks or by means of pumps communicating with the supply pipes, the substances in the machine may be subjected to suction or pulling force at the outlet end of the machine for causing them to travel therethrough.

The amount and rapidity of fiow of the two substances through the pipes60 and 62 may also be varied and controlled by suitable controlling means such as valves and/or flow meters, not shown in connection with the present form of the machine.

The two substances, namely the liqueous bitumen and the emulsier, are thus introduced through the pipes 60 and .62 to the Y 54, which constitutes a closed, confined receiving or mix-v ing chamber in the present form of the machine.

At the instant when the bitumen meets the emulsier there is a foaming action which greatly increases the volume of the mixture and spreads the bitumen into thin films, forming a coarse or a rough emulsion with the bitumen as the external phase-in other words, drops of emulsifier surrounded by films of bitumen constituting a primary emulsion. The foaming,

frothing action serves to stretch the films of bitumen. The primary emulsion is then immediately removed from the zone of formation and is subjected to agitation whereby the films o f bitumen are broken up into minute particles and are. thoroughly dispersed and diffused. This produces a coarse or rough emulsion with the bitumen as the internal phase. In other words, the emulsion is inverted and this secondary emulsion consists of particles of bitumen surrounded by lms of the emulsier.

Due to the forces which cause the substances to travel through the machine, the primary emulsion is immediately carried out of the Y 54 or 'fil mixing chamber through the pipe and is received into the recess 48 of the arbor 34. The emulsion is then forced .to travel in a reverse direction out of said recess and around the end of the tube 50, which is sufficiently spaced from 'the walls of the recess`to permit such outward travel'without'clogging or excessive back pressure.

It willbe understood that the forcible introduction of the primary emulsion to the recess 48 and its removal therefrom by reverse travel causes considerable agitation of the substance so that the emulsion becomes inverted to form a relatively coarse internal phase emulsion, or in other words,

.particles of bitumen surrounded by av film of emulsier.

The coarse or secondary emulsion with bitumen as the internal phase is now caused to travel through the close elongated space between the surfaces of the sleeve 20 and the arbor 34, the latter member being rotated by its connections with the motor40. 'Ihese coacting surfaces act to stretch, sub-divide, roll and spread the particles of bitumen through the emulsier, and thus'form a tertiary emulsion. The space between these surfaces is such as tofpromote the stretching, sub-dividing, spreading, rolling, diffusing and mixing action, and to that lend the surfaces maybe suitably serrated or otherwise deformed or roughened.

The fineness and uniformity of the nished product is controlled toA considerable extent, both by the size and character of the space between the surfaces and by the speed of the movement of )the surfaces with respect to each other. It is desirable to have the annular space between these surfaces slightly tapered from front to rear so that there is a constant decrease in the space between the surfaces as the emulsion passes between them: This is accomplished by the tapered' formation of the arbor 34 and it may be regulated by longitudinal adjustment of the sleeve 20. its end by a combined closing plate and bearing .Upon leaving the annular space between the surfaces the emulsion is discharged against the face of the peripheral fiange 46 of the arbor and is thrown outwardly by centrifugal force toward the wall of the casing 12. This accomplishes a re-mixing action and also causes the entrapped air to be released so as to render the emulsion more liquid. This centrifugal action also tends to exert a pull on the emulsion stream, thus increasing flow. u

The emulsion is then discharged from the casing 12 through a substantially tangential outlet 70 located at the bottom of the casing. From the outlet the emulsion may be received into any suitable receptacle or container where it prefer-- ably is rapidly cooled to normal temperature, by any suitable means, to increase stability, after which it is ready to be stored or shipped.

After the emulsion has reached this condition' it is, and remains, more uniform and stable through any of the usual conditions of handling, .shipping or storing than any of the emulsions of which I know, and will still break down from the emulsion form when spread into thin films, in shorter time and under conditions which are most desirable from the standpoint of practical use. Moreover, the characteristics of the bitumen are not substantially altered, unless this is done deliberately, and the relative volumes of the materials making up the emulsion remain constant throughout the process carried on by the operation of this machine.

I purposely make use of the formation of the original or primary bitumen external phase emulsion because I have found that this is advantageous in breaking the bitumen into films, and that the formation of this lm in the thinnest -form is facilitated by producing this primary emulsion at a preferred combining temperature. Proper regulation of combining temperature will produce maximum frothing or 'foaming action, and thus maximum thinness of the film. By producing thinner film at this stage, the amount of grinding necessary for securing any necessary neness of particles. is reduced, and the requisite flneness is secured with more certainty'.

The immediate removal of the emulsion from the zone of formation before the bitumen can agglomerate and bringing about the inversion of phase' without changing the relative proportions of the ingredients, is also important.

vThen by causing the secondary emulsion to pass between the elongated surfaces forthe grinding action, the coarse emulsion will be changed to one of finer form. The passing of the material between converging moving surfaces causes a greater'variation of sizes than would otherwise result, thus making for low voidage between bitumen particles and permitting maximum bitumen content as well as making for minimum surface area and thereby permitting the use of a minimum of emulsier. These results are attained without sacrifice 'of uidity.

In the form shown in Figures 4, 5 and 6, like parts are designated by the same numerals, except as otherwise indicated.

In this form two frusto-conical coacting surfaces are employed, the one being the internal PSW of a portion 72 of the casing, and the/ other eing the external surface of an arbor member 74 plined on the Aarbor shaft 36. y

Inlgs type of machine a chamber 76 is formed at th itial end of the machine itself, this cham` ber being of cylindrical form and being closed at member 78, which providesa bearing at one` end of the shaft 36 and is held in place by means of cap screws 80.

In Figure 5 there are shown the two pressure 5 containers for the liqueous bitumen and the emulsifier, these containers being designated by the numerals 82 and 84. From the containers pipes 86 and 88 lead to and communicate with opposite sides of the chamber 76 of the machine and are l equipped with suitable controlling valves designated as 90 and` 92 respectively.

The two liqueous substances are introduced at proper temperatures and in suitable quantities as controlled by the valves 90 and 92 to the l chamber 76 where the primary orexternal phase emulsion is formed.

The space at the initial end of the chamber 76 or adjacent to the inlet means 90 and 92, constitutes the zone of formation within. which foaming action of substances takes place and the primary emulsion is formed, and from which it is immediately withdrawn and subjected to agitation. This is accomplished by'a spiral blade 94 on the 'shaft 36 in the terminal portion of the cylindrical chamber 76.

Ihis agitation causes the inversion of the external phase emulsion to an internal phase emulsion of coarse form, and this secondary emulsion is reduced by the coacting surfaces of the members 72 and 74 to the fine emulsion 4of the final or ztertiary form.

The centrifugal action upon the emulsion is produced by a plate 96 splined to the shaft 36 within the enlarged cylindrical portion 14 of the machine. As here shown, the plate 96 is spaced from the frusto-conical arbor member 74 and is provided with a series of fins 98 on its adjacent face which serve to cause rapid forward movement and amplified centrifugal action on the emulsion emerging from the annular space between the surfaces.

1t will be noted from Figure 4 that the taper to produce a convergence of the space between these members. The spacing between these coacting surfaces may be adjusted by means of an adjust-ing'nut 100 on the shaft 36 threaded into a boss 102 on the end plate 14 and bearing at its inner end against the centrifuging plate 96. A

lock nut 104 is provided for fixing and holding the adjustment when made.

If desired, a universal joint of common form,

designated generally by the numeral 106 may be interposed between the motor shaft 42 and the arbor shaft 36 for the purpose of compensating for variation in alignment of the shafts and also for permitting a slight longitudinal adjustment of the shaft 36 by means of the adjusting nut 100.

It may also be desirable to provide means for maintaining the temperature of the machine and particularly of the* substances therein at a relatively high point and for that purpose I have o5 formed the walls of the machine, including the mixing chamber '76, the tapered portion 72 and the enlarged cylindrical portion 12, with a jacket- 108 to which live steam may be introduced by means of a pipe 110. (See Figure 6.) Water of condensation may be removed from the steam jacket through an exhaust pipe 11.2, located near the discharge 70 for the-bitumen.

` In the form shown in Figure 'I the machine is quite similar to that just described, but the chamber to which the liqueous substances are introducedl is considerably elongated and is designated by the numeral114.

` In this form the supply pipes 86 and 88 preferably are not in transverse alignment. The pipe 88 through which the emulsifier, enters is located at the extreme initial end of the chamber 114, while the pipe 86 for the liqueous bitumen is spaced longitudinally therefrom a suitable distance.l Mounted on theshaft 36 within the chamber 114 is an interrupted spiral blade.4 The initial portion of this blade is designated by the numeral and it acts as a wiper for the purpose of removing the liqueous substances from the outlets of the pipes 88 and 86 which are located respectively at the opposite ends of the blade In other words, the wiper blade 95 takes alternate quantities of emulsier and liqueous bitumen and causes them to be mixed in the initial end of the chamber. It serves to keep clear the outlets tothe supply pipes and equalizes the quantities of liqueous substance going to form the primary emulsion.

The second and longer portion of the spiral is an agitating blade spaced from the first blade 95 and designated by the numeral 116. The blade 116 acts upon the emulsion after it leaves the initial end of the chamber and causes a thorough andv complete agitation for completely transforming the emulsion into the secondary stage before it passes to the 'annularv space between the surfaces of the'members '72 and 74. In other Words, `provision is made inthe elongated chamber 114 for equalizing the quantities of liqueous substances and for more thoroughly agitating the emulsion before it is subjected to the grinding' and tearing actionof the coacting surfaces.

In Figure 8 there is shown a machine including a base 10 upon which is mounted an elongated tapered casing 118 within which an arbor shaft 36 is arranged for rotation. At the initial or smaller end of the casing 118 are arranged the supply pipes 86 and 88 for introducing the liqueous substances.

Formed on or fixed to the shaft 36 is a tapered member designated generally by the numeral 120 and this member combines the functions of agi- ,tating the emulsion and furnishing the coacting grinding surfaces.

The member 120 has a spiral formation throughout a considerable portion of its length, whereby there are produced relatively narrow spiral surfaces 122 coacting with the inner surface of the casing 118 and also a spirally arranged recess 124. The spiral surface 122 preferably approaches gradually more closely to the inner surface of the casing member to produce the converging surfaces which have been previously discussed at considerable length.

The spiral recess 124 begins at a point spaced suitably from the supply pipes 86 and 88 and gradually decreases in depth toward the larger end of the rotating or arbor member 120 The initial end of the casing 118 serves as a small substantially closed mixing chamber for the liqueous bitumen'and the emulsier, wherein is formed the primary or external phase emulsion. The primary emulsion is immediately acted upon and withdrawn from the mixing chamber and is agitated by the rotating spiral portion oi' the member 120 for inverting it to the secondary phase emulsion.

The emulsion as it travels through the casing 118 is subjected not only to agitation but also to the grinding action between the surfaces 122 and angles to that of the member 1.30.

surfaces for the spiral portion A122, and in addi- I tion they may be utilized either for retarding or accelerating the ow of emulsion, depending upon the directionpf rotation of the member and the direction of inclination of said grooves, as will be readily understood.

Figure 9 discloses a still different type of machine` including a substantially cylindrical casing 128 in which a rotor or arbor member 130 is arranged for rotation. The member 130 is cylindrical and ts snugly within the casing 128, but is arranged slightly eccentric thereto, whereby the space between their surfaces gradually converges in the direction of rotation and. toward the discharge port 132.

The space between the casing 128 and rotary member 130 is enlarged at one side of the machine to form an inlet and mixingchamber 134 with which the supply pipes 136 and 138 communicate. Preferably one of the pipes such as 136 communicates with the mixing chamber 134 slightly in-advance of the other pipe such as 138, with respect to the direction of rotation of the member .130, so that there will be a preliminary agitation of the substance entering through the first mentioned pipe.

The primary external phase emulsion is formed in the chamber 134 and is immediately withdrawn therefrom by pressure or suction or both and by the action of the rotating member 130, and is thereby agitated to form the secondary phase emulsion of coarse form. This emulsion immediately proceeds through the space between the casing wall 128 and the rotating member 130 and is subjected to the stretching, rolling and spreading action which reduces it to the teritary stage before it passes through the outlet 132.

In this form of the machine a centrifuging plate 140 is carried and driven by a shaft 142 arranged for rotation on an axis substantially at right The plate 140 faces the outlet port 132 of the casing and may -be formed on its face with radial fins 144 for increasing the agitation and centrifugal action of the plate 140, which is held in place by a closing plate 146-which also provides a bearing for the shaft 142 and is secured to the casing by means of cap screws 148.

The emulsion which passes through the discharge port 132 is subjected to centrifugal action by thev plate 140 and its ns 144 and is discharged into a chamber 150 from which a pipe 152 leads the emulsion to the desired place of storage.

In Figures 10 and 11 there is shown a frusto-,

conical arbor grinding member 154 which may be substituted for the corresponding member which is shown for instance in Figure 4. The member 154, as here shown, is formed with a series of circumferentially spaced, longitudinally arranged grooves, which preferably are of angular formation. The grooves 156 open to the initial end of the member l54'where they are of considerable depth but they decrease in depth 'toward the other end of the member and prefer-v ably taper out or merge into the surface thereof before reaching the larger or terminal end.

` The surface of the grinding member 154 and its grooves 156 cooperate with a coacting surface such as 158 to provide an elongated aperture through which the secondary emulsion iscaused to pass', as before stated. It will be observed that on account of the progressive decrease in depthv of the grooves 156 there is provided a variation of convergence between coacting surfaces. That is to say, the bottoms of the grooves 156 will present a different degree of convergence with respect to the surface 158 than that presented by the general surface of the member 154. Inasmuch as the deeper ends of the grooves 156 open to thesrnaller end of the rotating member 154, they greatly facilitate the introduction of the comparatively coarse secondary emulsion to the space between the surface of said member and the casing. From these grooves the emulvsion is thrown out by centrifugal action of the rotor; against the smooth surface of the coact- .ing member, thereby increasing the spreading and rolling action and assisting in the opera- The decrease in depth of thel .uid material forces it toward the ends of the f sloping grooves, insuring that the substance will be spread over a larger areaof the coacting surfaces, and that none ofthe material will pass out of the narrow aperture without being reduced to the vdesired state of neness.

The longitudinally extending spirally arranged groove 124 of the form shown in Figure 8 accomplishes the same function.

If desired the surface of the member 154 may be formed with a series of kerfs or serrations opening to the'grooves 156 on the trailing edges thereof with respect to the direction of rotation. These kerfs or serrations constitute roughened surfaces for the grinding member. They serve to stretch and spread the particles of emulsion traveling from the grooves 156 to the narrower surface between members 154 and 158 as the former member is rotated.

It has been found that a machine having the characteristics set forth herein is very eflicient for producing a bituminous emulsion possessing the desired properties of flneness and uniformity of texture and complete coating and enveloping of individual particles of bitumen with the emulsifying solution.

It is to be understood that any suitable and well known means may be employed for varying the speed of the prime mover to obtain desired speed of the grinding member. f

.It should also be noted that any suitable means,

of which the steam jacket 108-is an illustration,

" rotary movement of the grinding member, which may-of course, be supplemented by pressure or suction effect applied to the liqueous substances aspreviously referred to.

It is important to introduce or iiow directly together the emulsifler and liqueous bitumen under pressure, into a confined and substantially closed mixing chamber which is free and clear and contains no agitating member. By so doing I purposely take advantage of the formation under such circumstances of the primary emulsion with bitumen as its external phase, and take advantage of the foaming, frothing action thus produced, and utilize this natural phenomenon for accomplishing the first step in a continuous emul' siflcation process, namely, the formation of thin films rather than formation of threads. The use of continuous and substantial pressure behind the liquid materials is important in procuring the foaming and frothing action for the forming of the primary emulsion in the substantially enclosed mixing chamber, and also for immediately removing the primary emulsion from the zone of formation.

Subjecting bituminous emulsion to centrifugal action, immediately after its formation, is also important. This step reduces the hot emulsion from a foamy to more uid state, releases air and increases thoroughness of mixing and dispersion,

. so that the emulsion be stable and remain closely approximated relatively moving surfaces may be of any desired shape and arrangement, and I ldo not desire to be understood as limiting myself to the specific forms herein shown and described. Furthermore, the convergence of the surfaces may be secured in different ways, some' of which are illustrated in the various embodiments herein shown and described.

I claim as my invention:-

l. A machine for making bituminous emulsion .comprising a mixing chamber, separate means for flowing directly together into said chamber liqueous bitumen and an emulsifler, whereby there is formed a primary emulsion with bitumen as the external phase, means for removing the emulsion from` the zone of formation and agitating it to form a secondary emulsion with bitumen asl theinternal phase, a pair of coacting, relatively movable surfaces between which thesecondary emulsion is caused to pass for exerting a sub-dividing, rolling and spreading action thereon, whereby the particles arerreduced in size and dispersion is increased, and flat disk means for subjecting-the stream of emulsion to centrifugal action as it leaves the space between said surfaces.

2. A machine for making bituminous emulsion comprising a chamber, separate means for introducing to said chambenheated liqueous bitumen and an emulsifler whereby there is formed a primary emulsion with bitumen as the external phase, means for immediately removing said priary emulsion from the zone of formation and causing an agitation whereby-it is converted to a secondary emulsion with bitumen as the internal phase, an elongated aperture between two surfaces through which the emulsion is caused to pass, means for moving one surface relative to, the other to subject the emulsion to spreading and rolling action, and a flatl disc-like member-adjacent and extending across the outlet of said aperture, moving in a plane angular to the $1.15

of said aperture, for engaging the emulsion as it emerges from said aperture and subjecting it to centrifugal action.

3. A machine for forming a bituminous emulsion comprising a casing having a. substantially closed mixing chamber, means for flowing directly togetherinto said chamber liqueous bitumen and an emulsifler for forming a primary emulsion with bitumen as the external phase, positive means being provided for immediately withdrawing the primary emulsion from the zone of formation and agitating it to convert into a secondary emulsion with bitumen as the internal phase, an arbor grinding member rotatably mounted in said casing and having a surface coacting with the surface thereof for forming an elongated aperture through which the secondary emulsion is caused to pass for spreading and rolling the particles, for reducing them and increasing dispersion, one of said surfaces being inclined relative to the other to produce a convergence of the elongated aperture toward` its outlet end, and movable means arranged transversely only of said aperture and having a face extending across its outlet end for subjecting the emerging emulsion to-centrifug'al action.

4. A machine for forming a bituminous emulsion comprising a casing having a substantially closed mixingchamber, means for flowing directly together into said chamber liqueous bitumen and an emulsiiier for forming a primary emulsion with bitumen as the external phase, means being provided for immediatelyl withdrawing the primary emulsion from the zoneof formation and agitating it to convert into a secondary emulsion with bitumen as the internal phase, an arbor grinding member rotatably mounted in said casing and having a cylindrical surface coacting with the interior surface thereof for forming an elongated cylindrical aperture through which the secondary emulsion is caused to pass for spreading and rolling the particles, for reducing them and increasing dispersion, one of said surfaces being inclined relative to the other to produce a convergence of the elongated aperture toward its outlet end, saidI grinding member being formed with a groove in its surface, which groove decreases in depth from the -initial end of the member and lengthwise of its axis, whereby a differently converging spacing is procured with respect to said coacting surface.

5. A machine for forming 4bituminous emulsion comprising a chamber, means for introducing to said chamber liqueous bitumen and an emulsifier whereby an emulsion is produced, a pair of surfaces producing an elongated aperture through which the emulsion is caused to travel. means for moving one surface relative to the other, and a rotating disk transverse of said aperture for subjecting the emulsion to centrifugal action as it leaves said aperture.

6. A machine for making bituminous emulsion comprising a pair of closely approximated surfaces consisting of a vstator and a rotor, means for introducing liqueous bitumen and an emulsiner to the space between said surfaces where they are subjected to a sub-dividing, spreading and rolling action, and a disk having a surface extending across the outlet end of said space for subjecting the emerging stream of emulsion to centrifugal action immediately after it leaves the space between said surfaces.

7. A machine for making bituminous emulsion comprising a mixing chamber, separaitc inlet means for flowing directly together into said chamber, under pressure, liqueous bitumen and an emulsier, whereby there is formed a primary emulsion with bitumen as the external phase, wipingmeans moving across the respective inlet means for picking up uniform quantities of the substances to effect maximum frothing action, means for immediately removing the primary emulsion from the zone of commingling and causing agitation, an elongated, narrow converging aperture between two surfaces through which the substance is caused to pass, one of said surfaces being formed with a groove decreasing gradually in depth lengthwise of the axis of rotation, and a fiat disk for moving one surface relative to the other to subject the substance to sub-dividing, rolling and spreading action.

8. A machine for making bituminous emulsion comprising a mixing chamber, separate inlet means for flowing directly together into4 said chamber, under pressure, liqueous bitumen and an emulsier, whereby there is formed a primary emulsion with bitumen as the external phase, wiping means moving across the respective inlet means for picking up uniform quantities of the substances to effect maximum frothing action, means for immediately removing the primary emulsion from the zone of commingling and causing agitation, an elongated, cylindrical, narrow, converging aperture between two surfaces through which the substance is caused to pass, one of said surfaces being formed with a groove decreasing gradually in depth lengthwise of the vaxis of rotation, means for moving one surface relative to the other to subject the substance to sub-dividing, rolling and spreading action, and means for subjecting the stream of emulsion to centrifugal action as it leaves the space between said surfaces.

9. A machine for making bituminous emulsion comprising a mixing chamber, separate inlet means for flowing directlytogether into said chamber, under pressure, liqueous bitumen and an emulsier, whereby there is formed a primary emulsion with bitumen as the external phase,' .wiping means moving across the respective inlet means for picking up uniform quantities of the substances to effect maximum frothing action, means for immediately removing the primary emulsion from the zone of commingling and causing agitation, an elongated, cylindrical, narrow, converging aperture between two surfaces through which the substance is caused to pass,

one of said surfaces being formed with a groove y decreasing gradually in depth lengthwise of the axis of rotation, means for moving one surface relative to the other to subject the substance to sub-dividing, rolling and spreading action, means for adjusting one surface relative to the other to regulate the size of said aperture, and means for subjecting the stream of emulsion to centrifugal action as it leaves the space between said surfaces.

10. A machine for making bituminous emulsion comprising a mixing chamber, separate inlet means for flowing directly together into said chamber, under pressure, liqueous bitumen and an emulsifier, whereby there is formed a primary emulsion with bitumen as the external phase, means for immediately removing the primary emulsion from the zone of commingling and causing agitation, an elongated, cylindrical, narrow, converging aperture between two surfaces through which the substance is caused to pass, one of said surfaces being formed with a groove decreasing gradually in depth lengthwise of the axis of rotation, means for moving one surface relative to the other to subject the substance to sub-dividing, rolling and spreading action, means for adjusting one surface relative to the other to regulate the size of said aperture, and means for subjecting the stream of emulsion tocentrifugal action as it leaves the space between saidI surfaces.

ll. A machine for making bituminous emulsion comprising a mixing chamber, separate inlet means for introducing to said chamber, under pressure, liqueous bitumen and an emulsifer, wiping means moving across the respective inlet means for picking up uniformquantities of the substancesto effect maximum frothing action, an elongated, cylindrical, narrow aperture between two relatively movable surfaces through which said substance is caused to pass for effecting a sub-dividing,l rolling and spreading action, and means for subjectingv the stream of emulsion to centrifugal action as it leaves the space between said surfaces. Y

LEON R. MACKENZIE.

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