US1373743A - Method and mechanism for centrifugally separating substances - Google Patents

Description

CENTRIFUGALLY SEPARATING SUBSTANCES. LICATION FILED SEPT-4, 1920.

L. D. JONES.

k \L a L. n, JONES; METHOD AND MECHANISM FOR CENTRIFUGALLY SEPARATING SUBSTANCES.-

APPLICATION FILED SEPT- 4, 1920- 7 1,373,743. Patented Apr. 5, 1921.

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IIIII 3 SHEETSSHEET 3- ING SUBSTANCES- Patented Apr. 5, 1921. 32

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, APPLICATION FILED SEPT. 4, I920- METHOD AND MECHANISM FOR CENTBIFUGALLY SEPARAT unrrso STATES e rsn'r OFFICE.

LEO D. JONES, 0F PHILADELPHIA. PENNSYLVANIA. ASSIGNOR TO THE SHARPLES SPECIALTY COMPANY, OF WEST CHESTER, PENNSYLVANIA, A CORPORATION OF DELAWARE.

Specification of Letters Patent.

Patented Apr. 5, 1921.

Application filed September 4, 1920. Serial No. 408,336.

for effecting separations where three constituents are. involved, with a view to 1ninimizing the objectionable effects on the separation of the two lighter constituents due to changes in the density of the heaviest constituents and nice adjustments of the dams therefor. as. more specifically in the treatment of dilute cylinder stock or petroleiun oils containing wax. by subjecting the same together with a heavier carrier liquid. such as brine. to centrifugal force in a, bowl having a plurality of outlets through which the separated substances are discharged respectively. It will be understood. however. that while the improven'ients have a highly important use in the separation of wax fromoil. the principles involved are not to be considered as limited to this use but are of more general appliaition as, for instance. to the separation of oil from soap water in which the soap has been precipitated by salt.

Specific advantageous functions of the invention are. found in its capacity for segregating more than two substances by a ma chine having two or more discharge passages and improved means for controlling the discharge of the separated substances with avoidance of the necessity for the refinement in construction and adjustment and the elimination of 'the sensitiveness of operation involved in the separation of more than two constituents by known centrifugal means and methods. and also in the comparative independence of the sepa 'ation of the two lighter constituents upon the adjustment of the dams and the specific gravity of the heaviest constituent, and vice versn. and the comparative independence of the. separation of the two heavier constituents upon the adjustment of the dams and the specific gravity of the lightest constituent.

As an example of the sensitiveness of the customary practice. consider the operation of a centrifugal machine designed to effect the discharge of wax with the carrier liquid through one passage and oil through another. Here an increase of inch in the axialdistance of the weir over which the wax and carrier liquid flows over that required for normal operationhas effected a.

change of relations which cause the discharge of oil with the wax, and a decrease of mch from that required for normal operation has been found to cause the discharge of wax with the oil, whereas in the present method a variation of 5% inch in either di rection in the position of the weir for the carrier liquid has been found to have no effect upon the efliciency of the separation of the wax from the oil.

Variations in the density of the carrier liquid may likewise take )lace without substantially effecting the efficiency of the separation of the oil and wax by the. present improvements. whereas a slight variation in the density of the carrier liquid has heretofore interfered with and prevented the desired separations.

In separating a mixture of three substances each substance may be discharged separately but it frequently happens that it is desirable or more convenient to discharge one separately on the one hand, and discharge a mixture of the other two constituents (usually the heavier two) on the other. This is most efiiciently accomplished by stratifying the three constituents and controlling the separation according to myinvention, followed by reuniting the two to be discharged together while still under the influence of centrifugal force and discharging the two products through separate discharge passages. I

The invention is practised by means of the structures set out in the following description and the accompanying drawings in illustration thereof.

In the drawings, Figure 1 is a broken vertical sectional view of the top of a centrifugal separator bowl constructed in accordance with the invention; Fig. 2 is a sectional view taken on the line 2-2* of Fig. 1: Fi

3 is a sectional view taken on the line 3*-3" of Fig. 1; Fig. 4 is a sectional view taken on the line 4*4* of Fig. 1; Fig. 5 1s a broken vertical sectional view of the top of a centrifugal bowl of modified constructiontaken on the line *5 of Fig. 6, by which three substances are separated in the ,bowl under control of respective dams therefor followed by discharging two of them together; Fig. 5 6 is a sectional view taken on the line (i -6 of Fig. 5; and Figs. '2, 8, 9, 9*, and 10 are vertical sectional views of vessels designed to illustrate diagrammatically conditions involved in the separation of three substances, 10 as in the case of petroleum oil containing wax with the use of brine as a carrier liquid.

The construction illustrated in Figs. 1 to 4 inclusive comprises a bowl 1 having a neck 2 connected by a coupling 3 with a spindle 4, by which'the bowl is suspended and revolved.

The bowl 1 is, provided at its top with three passages or sets of passages 5, 6-6 and 7 for discharging substances'of difi'erent densities, as oil, waxand brine, which have been Stratified in the bowl by its revolution.

The discharge passages 5 communicate at their inlets with the bowl body through the concentric cylindrical chamber 8, into which the oil, or otherwise the lightest of the separated substances, flows over the ring 9, and through passages 5, the passages discharging into the channel 10 concentric with 0 the axis of rotation and having the concen-. tric annular dam or ring 11 over which the liquid flows. The ring or dam 11 is made exchangeable for dams or rings of different sizes and characteristics, for accommodation to different conditions, by means of the collar 12 detachably connected with-the neck 2 for engaging such dams thereto.

The discharge passages 6 and 6 are connected through the cylindrical chamber 13,

which is disposed concentrically with. the

bowl in the neck thereof and has near its top the concentric ring or annular dam 14, the chambers 8 and 13 being separated by the diaphragm 15.

The discharge passages 7 lead from the interior of the bowl body 1, from inlets exterior to the passages 6, through the neck 2, to the annular channel 16, which discharges over a ring or annular dam 17 concentric with the axis of revolution, the ring being retained so that substitutions of different rings can be effected for different con- *ditions by means of the collar 18 connected detachably with thebowl neck. f

As illustrated in the modified construction of Figs. 5 and 6, the bowl 19, having the neck'20, is provided with the passages 21 and 22 connected by the concentric chamber 23 for discharging the lightest sub- 0 stance,:as oil, which flows thereto over the inner edge ofthe dam or ring 24,- and the passages '25 for discharging together the two heavier substances, as wax and brine, which are delivered therefrom to the channel 26 i p andthence over the dam or ring 27, themingled constituents of different densities by the present invention, assume, that the S0 vessel 31 is provided with the dams 32 and 33 adjusted so that the contact surface (1-11 of a resolved mixture (for instance of brine and wax free oil assumed for the purpose to separate by gravity) will, upon gravity separation, be between the upper and lower edges *of the dam 32 when the upper surface of oil is level with oroverflows this dam and. the upper surface of the column of brine between the dams 32'and 33 is level with or overflows the dam 33, as illustrated in Fig. 7. If, now, oil containing precipitated wax is poured intothe oil in the vessel 31, the wax may be assumed to gravitate to the surface of the brine and collect in a 5 layer between the oil and brine, having a top surface 6-?) above the surface a-a and a bottom surface cc below the surface a-a, asillustrated in Fig. 8. With, the desired adjustments and conditions (as the mingled constituents are continuously poured into the vessel), the wax would break the 'brineseal and leak under the dam 32' and escape over the dam 33 the lighter wax free oil flowing off over the dam '32. It 'will be understood that a change in the height of thedam 33 varies the height of the adjacent column of brine and thus the plane of contact between the layers of oil and wax. A slight elevation of this dam will elevate this contact surface so that the wax will occupy all the separating space for the oil and the oil will flow over the dam 32 without its wax having been separated, and a slight lowering of the 11 dam 33 will lower this contact surface and permit the oilto escape with the wax under dam 32 andover the dam 33, thus defeating the desired purpose of their separation. Likewise, if with dams properly adjusted, there should be a variation in the density of the brine,.the oil would escape with the wax in case of decreased brine density and the wax would discharge with the oil in case of increased brine density. It follows then that, with this former type of separator or mode of operation, the efliciency of the separation of the two lighter substancesvaries with the density of the heaviest substance and the adjustment of the dams.

'found that comparatively Considering now (diagrammatically and analogously in illustration of the present invention as embodied in Figs. 1 and 5) the vessel 34, it is provided with the dams 35, 36 and 37 having successively lower corresponding parts. The vessel 34 as shown in Fig. 9, is designed for the discharge separately of oil, wax and brine resiectively, while this vessel, as shown in lig. 9, is designed for the discharge of separated oil on the one hand and wax and brine together on the other. The plane of contact (I -(Z of the layers of oil and wax is between the top and bottom of the dam 35, and the plane of contact c-e of the wax and brine between the bottoms of the dams 35 and 36; the dams 35, 36 and 37 being adjusted to the positions for effecting the desired operations. The contact surface between the oil and wax is controlled by the dams 35 and 36, and the contact surface between the wax and the brine is controlled by the dams 36 and 37 The contact surface between the Wax and the oil is independent of the height of the dam 37 and the density of the brine within certain limits to be specified, until this dam becomes so high that the contact surface between the wax and brine lies between the top and bottom of the dam 35, with the result that the wax is sealed from its dam -36 and will discharge with the oil, or, on the other hand, until the dam 37 becomes so low that the contact surface between the wax and brine falls below the dam 36 when the wax escapes through, the brine column adjacent to the dam 37 For similar reasons the contact surface between the oil and wax is also independent of the density of the brine within certain limits.

It follows from this that the efficiency of the separation of the two lighter substances is independent, within certain limits, of the adjustment of the brine dam and of the density of the brine.

Regard the construction shown in Figs. 10 and 10 (which is analogous to that shown in Figs. 9 and 9) as a vertical section through a bowl 34 divided on an axial plane and having dams 35, 36' and 37 for controlling the flow through the respective discharge passa es, 35, 36" and 37", or 35 and 36"--3 In practice, it has been wide variations can be made in the distance of the weir or overflow edge of the dam 37 analogous to the parts 17 and 27 shownin Figs. 1 and 5, without changing the contact surface between the oil and wax or at all interfering with their separation and separate discharge.

In the bowls of Figs. ,1 and 5, by reason of these characteristic features, the separation of wax from oil is independent of variations in the density of the brine and the oil mixture within certain limits, and also of the adjustment of the brine dam within certain limits, for the contact surface between them is within wide limits independent of the density of the brine and the adjustment of the brine dam, whereas in the former practice it was directly dependent thereon and varied therewith.

The present invention is of distinct advantage in separating oil and wax with a carrier liquid. for the position of the contact surface between the oil and wax and therefore the separation varies with the relative specific gravities of the oil and wax, which is approximatelyconstant in lots of oil obtained from the same source, whereas in the former practice the contact surfaces were dependent upon the specific gravities of the oil and brine which were liable to wide variations due to making up the brine and oil solutions.

These advantages of the new method, while well illustrated by the specific case of the separation of wax from oil, are equally true for separation of any three substances.

Having described my invention, I claim:

1. The method of separating three substances having differcnt densities which consists in subjecting them to centrifugal force and controlling the distance of the contact surfaces of the centrifugally stratified I sists in centrifugally stratifying and controlling the place of separation of two of the contacting substances so that such place is substantially independent of variations in the density of the third substance, and separately delivering the respective substances so that the density of the third substance can be varied without substantially varying the distance from the center of rotation to the place of separation of the other substances.

3. The method of treating three substances of different densities which consists in centrifugally stratifying and controlling the place of separation of two of the substances so that such place is substantially independent of, variations in the density 0 the third substance, separately delivering the respective substances so that the density of the third substance can be varied without substantially varying the distance from the center of rotation of this place of separation of the other substances, and reuniting and discharging together two of the sepaated substances.

4. The method of separating wax from petroleum oil which consists in chilling the oil to precipitate the Wax, and subjecting the chilled oil together with an immiscible with three passages having independent communications therewith, a common outlet for two of said'passages and respective controllmg means dlsposed at difierent distances from the axis of the bowl, said bowl and controlling means adapted for strati fying three mixed substances and delivering said substances .through the respective passages. 1

In testimony whereof I have hereunto set my name this 31st day of August,11920.

LEO D. JONES.

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