USRE23781E - Spraying device - Google Patents

Description

Feb. 9, 1954 H. c. scHu-n' SPRAYING DEVICE Original Filed Aug. 20, 1949 5. x Y Em r o v A u n A m m 7A m w Reuued Feb. 9, 1954 SPRAYING vDEVICE Hermann C.

Schutt, Framingham, Mass., assigner to Stone Webster Engineering Corporation,

Boston, Mass.,

Original No. 2,602,002, dated a corporation of Massachusetts July 1, 1952, Serial No. 111,515, August 20, 1949. Application for reissue July 1, 1953, Serial No. 365,573

(Cl. 299-453) Matter enclosed in heavy brackets appears in the original patent but forms no part of this 13 Claims.

reissue specification; matter printed in italics indicates the This invention relates to spraying devices and relates more particularly to centrifugal spraying devices of utility especially for operating on a fluid mixture or solution of solid and liquid to atomize the same into a finely divided state in which evaporation of the solvent or the liquid from the particles so formed may proceed in a more rapid and efficient manner for recovery of the dry solid in a discrete particle form.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to explain the principles of the invention.

An object of this' invention is to enable the attainment and the maintenance of a state of homogeneity in the fluid arriving at the spray head through the provision of a novel and improved system of moving and fixed vanes in the spray device in order that the particles formed by discharge therefrom into a drying space may be of the same uniform size and consistency so as to possess the same rate of [all] fall through the drying space and thereby achieve uniform drying.

Another object of this invention is to enable a more thorough and effective atomization and/or dispersion of such a fluid into a drying medium in a drying tower and a more rapid, eilicient and uniform drying of the particles thereinthrough the provision of a novel and improved system of stationary diffusion ports or nozzles in the spraying device operative to impart to the particles on discharge. motion in a circular direction around the spray head of the device, which motion is advantageously counter to that of the contacting drying medium.

Another object of this invention is to enable the direction of discharge of fluid from the spray head to be controlled from a distance so as to permit the fluid to be discharged at will over a wide range of angles, through the provision of a novel and improved positionally adjustable valving rotor in accordance with this invention.

Another object of this invention is to aid the additions made by reissue.

dispersion effect of the nozzles, prevent clogging of the nozzles, and permit of adjustment of spray distance or radius, through the provision in the spray head of a novel and improved valving rotor unit variable as to speed and therefore as to frequency of interruption of discharge through the stationary diffusion nozzles.

Another object of this invention is to impart to the fluid, merely by varying motor speed, an increasing pressure commensurate with lthe increased frequency of discharge interruption through the spray head while maintaining a substantially constant rate of discharge without varying the external pressure, throughthe provision of the moving vanes, acting as pumping element, of this invention.

Of the drawing:

Fig. 1 is a view in vertical section with parts in elevation of a typical and illustrative embodiment of the spray device in accordance with this invention showing the device installed in the top of a [driving] drying tower, the section plane corresponding to the line I-I of Fig. 2;

Fig. 2 is a view in section of the spray head of the device of Fig. l. taken along the line 2--2 of Fig. l; and

Fig. 3 isa view taken generally along the line I-B of Fig. 1 showing the arrangement of the dispersion nozzles of the spray device.

In accordance with the illustrative embodiment of this invention, an upright stationary rotor shaft housing I, preferably tubular, is detachably bolted or otherwise sealingly connected at its lower end, as viewed in Fig. l, to a stationary, generally hollow spray head 2. The housing I encases a'rotor shaft 3, coaxial therewith, whose lower end is provided with a cylindrical valving rotor I2 detachably connected thereto and encased by the spray head. The shaft I3 is detachably connected at its other end to a prime mover 4. Fluid material to be sprayed is adapted to be supplied to the interior of the housing I adjacent the top thereof for which purpose the housing I as here embodied is provided with a suitable inlet nozzle 5. The nozzle l advantageously is formed integrally with an annular flange 6 also preferably integral and concentric with the housing I, which serves as a belting flange by which the device may be supported in an upright position, as shown in Fig. l, with the spray head 2 disposed in the interior of a drying tower la into which the atomized fluid is to be discharged from the spray head and descend in contact with a suitable drying medium and be dried. The tower la is suitably apertured at its top, as at lb, for the introduction of the spray device and is provided, preferably, with an annular bolting flange 1 circumfercntially of the opening, sealingly engaged by the bolting flange 6.

A gland I at the top of the housing seals the housing against leakage of fluid around the shaft I and provides a [thrust] bearing for the shaft. Sets of impellers or vanes I are attached to the shaft I at successive intervals for rotation therewith and a corresponding number of sets of stationary vanes III are attached to the housing which serve to agitata, mix and homogenize fluid as it is impelled by the moving vanes I through the housing to the spray head. There may be any suitable number of moving and fixed sets of venes, depending on the type of the huid material and its tendency to separate. The nxed vanes in particular serve to maintain a homogeneous mixture, especially in the event some drying sas or steam is admixed with the fluid material to facilitate a hner dispersion oir the material through the spray head. Three sets of moving vanes ll and three sets of fixed vanes I are depicted in Fig. 1, each set preferably consisting of four vanes spaced at equal circumferential distances around the shaft or housing as the case may be. The varies 9 are preferably each of a contour providing a high thrust toward the spray head, with minimum drag in rotation which, in the case of Fig. l, is advantageously clockwise as viewed in top plan.

The lower end of the rotor shaft 3 extends into a well II formed in the base of the hollow spray head I, the well II providing a vertical journal bearing lubricated by the fluid supplied to the spray head although it may be independently lubricated from a bore in the shaft (not shown). In accordance with this invention, the well il is of a depth sufficient to permit of substantial axial movement of the shaft I in either direction from the intermediate position shown in Fig. i. The shaft I carries a positionally adjustable slotted valving rotor I2 adjacent its lower end, the rotor preferably being removably secured to the shaft as by means of a key II and set screw (not shown) and being adapted by its rotation to effect a continuous valving action on a number of Venturi-type dispersion nozzles Il arranged in superposed sets in the stationary spray head I. Three such sets are depicted in the spray head of the device as shown in Fig. l and the axial adjustability oi the rotor i2 enables selective valving of the sets to be effected, as will more fully appear hereinafter.

Means are shaft I so as to desired operative position the valving rotor II in relation to the sets of Venturitype nozzles Il. As here preferably embodied, the prime mover 4 which may be a steam or air turbine, but is preferably a variable speed electric motor, is removably coupled to the shaft I for direct' drive as by means of the mechanical coupling I5, on a standard I8 as byV means of a wheel and spindle unit I1 threadedly engaging a suitable arm Il on the prime mover. The standard I6 is bolted or otherwise suitably afllxed to the bolting flange 8. It will be obvious that pneumatic or hydraulic means may be employed for vertically adjusting the prime mover in lieu of the me chanical means shown. Rotation of the wlieelspindle unit I'I will eiiect axial movement of the prime mover 4 and hence of the valvingrotor I2.

The spray head 2 is constructed and arranged to provide a cylindrical rotor chamber it to which provided for axially adjusting the z and is vertically adjustably mounted the duid material is supplied in a homogeneous state and under pressure of the movable vanas l. from the housing I. advantageously. the housing I may be provided with an annular securing iiange Il through which bolts or other suitable means of fixation (not shown) may be passed into securing engagement with the spray head to effect a fluid-tight seal between the parts. In accordance with this invention also, the bore of the housing is preferably suitably flared at its terminus with the spray head to eil'ect a smooth now of the iiuid material to the top of the rotor chamber I9. To this end, the housing may be provided with a tapered portion 2i.

The valving rotor I2 is of cylindrical contour as noted and is apertured from top to bottom to provide a suitable number of passages Il through which the fluid material supplied to the chamber Il at the top of the rotor is adapted to pass to the bottom of the chamber. In this manner. the fluid in the chamber I9 offers negligible impedance to axial adjustment of the rotor in the chamber. The passages I2 are preferably arranged in a circular row concentric with the rotor and in uniformly circumferentially spaced relation to each other paralleling the rotational axis of the rotor. The circumferential periphery of the rotor II to provide communication with the passages 22 to the end that fluid material entering the passages II may be discharged under pressure from the rotor through one or more of the sets of Venturi-type nozzles Il. As here preferably embodied. the rotor Il chamber II concentric with the rotor and disposed midway between the top and bottom of the rotor. The chamber 13 is preferably of a width radially. equal or substantially equal to the diameter ofthe respective passages 22 with which passages it is in matching vertical alignment sons to be supplied with fluid material therefrom. The chamber Il is connected at intervals with the circumferential periphery of the rotor by a suitable number of radially extending sector shaped slots Il which are likewise disposed midway between the top and bottom of the rotor in equally circumferentially spaced relation to each other.

The rotor and its slots are vertically dimensioned circumferentially so as to be positionable vertically with the slots spanning vertically at leastA one of said vertically superposed sets of minimum and with the other sets of nozzles covered periphery. Preferably, however, bodied, mensioned so as to be positionable vertically with the slots spanning vertically a pair of adjacent and as here emsets of nozzles at least in part and with the remaining set covered by the rotor circumferential periphery. The slot width, or angular dimansion, at the rotor circumference is of a' magnitude sufficient to span preferablytwo nozzle openings in the same set at the same time as in accordance with the illustrative embodiment of this invention. Thus. a i

high frequency discontinuous. interrupted, or intermittent flow of fluid material through the nozzles Il is obtainable in order to aid the dispersian effect of the nozzles, and prevent clogging. Adjustment of the spray distance or radius is obtainable by varying the rotor speed and the selection of a discharge path as to direction and width is controllable at will.

l The superpcsed sets of Venturi nozzles I4 conmt'each of a suitable number 'of the nonies I4 is suitably radially pierced' is provided with an annularA by the rotor circulriierentialV the rotor and its slots are vertically di more or less tangentially arranged with respect to the rotor I2, each nozzle flaring outwardly from a circular inlet to a generally elliptical outlet. By this arrangement, a more eiilcient dispersion or atomizing eilect is obtained, and the fluid material discharging from the nozzles is given an initial rotary motion about the spray head, as viewed in Fig. 2 which promotes more efficient admixture and contact of the dispersed fluid material with a drying medium as in the tower la particularly when the drying medium is itself given a counter rotational movementl on entry into the tower.

The sets of nozzles I4 are also preferably-disposed and arranged in the spray head I!l in staggered relation to each other in azimuth as is indicated in Figs. 2 and 3. It will be evident that, with three sets of nozzles Il as here preferably employed, the arrangement is such that the discharge of fluid from the nozzles may be effected through a substantial vertical angle either horizontally as through the middle set, or downwardly through the bottom set, or upwardly through the top set or partly through the upper and middle or lower and middle sets. Various other suitable arrangements will be apparent to those skilled in the art. The vertical spacing of the sets of nozzles Il is preferably such that the rotor portions above and below the slots I4 can cover the openings of two of the sets while the third is uncovered or can cover the upper or lower set completely while the rotor slots 2l are in communication with both remaining sets, either the middle and lower or the middle and upper.

It will be evident that, in the operation of the spray device in accordance with this invention, the pressure imparted to the fluid material may be varied by merely varying the prime mover speed and without varying the external pressure. Thus, an increasing pressure commensurate with an increasing frequency of discharge interruption while maintaining a substantially constant rate of discharge, is obtainable through the provision of the moving vanes il acting as pumping elements in accordance with this invention.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention'and without sacrificing its chier advantage.

What is claimed is:

l. A spray device comprising a spray head having a valving rotor chamber to be supplied with fluid material under pressure and having separate sets of dispersion nozzles through which said fluid is adapted to be discharged from said chamber; means for supplying fluid material under pressure to said chamber; a valving rotor adjustable axially of its rotational axis with respect to said sets of nozzles, said rotor being internally channelled and apertured to provide at least one continuous passageway for leading said fluid material from said chamber into said nozzles, each said passageway terminating at the circumferential periphery of said rotor in a discharge opening movable into and out of register with successive nozzles, whereby on rotation of said rotor said discharge opening may be moved progressively into successive nozzles, through each of intermittently interrupted by and then out of register with the flow of said fluid material said successive nozzles bein! said movement oi 2. The device of claim i in which said sets are superposed.

3. The device of claim 2 in which said superposed sets are angularly offset in azimuth.

4. The device of claim 1 in which said nozzles have each a substantially circular inlet port and an ovoid outlet port and an interport periphery flaring outwardly from said inlet, to said outlet port.

5. The device of claim 1 in which said sets comprise an upper, a middle and a lower set, the Anozzles of the upper and lower sets extending angularly upwardly and downwardly, respectively, from the middle set which latter has its nozzles disposed substantially horizontally.

6. A spray device comprising means forming a pumping chamber adapted to be supplied with fluid material to be sprayed; pumping means in said chamber for imparting pressure to said fluid material in said chamber; a spray head having a valving rotor chamber adapted to be supplied with fluid material under pressure from said pumping chamber and having separate sets of dispersion nozzles through which said fluid is adapted to be discharged from said valving rotor chamber; a valving rotor adjustable axially of its rotational axis with respect to said sets of nozzles, said rotor being internally channelled and apertured to provide at least one continuous passageway for leading said fluid material from said chamber into said nozzles, each said passageway terminating at the circumferential periphery of saidvrotor in a discharge opening movable into and out of register with successive nozzles, whereby on rotation of said rotor said discharge opening may be moved progressively into and then out of register with successive nozzles, the flow of' said fluid material through each of said successive nozzles being intermittently interrupted by said movement of said opening into and out of register with said nozzles: and, means for selectively positioning said valving rotor relative to said sets for admitting fluid material to one or more of said sets, at will.

7. A spray device comprising a shaft housing adapted to be supplied with fluid material to be sprayed; a spray head having a valving rotor chamber adapted to be supplied with fluid material under pressure from said housing and having separate sets of dispersion nozzles through which said fluid is adapted to be discharged from said chamber; a valving rotor adjustable axially of its rotational axis with respect to said sets of nozzles, said rotor being internally channelled and apertured to provide at ieast'one continuous passageway for leading said fluid material from said chamber into said nozzles, each said passageway terminating at the circumferential periphery of said rotor in a discharge opening movable into and out of register with successive nozzles, whereby on rotation of said rotor said discharge opening may be moved progressively into and then out of register with successive nozzles, the flow of said fluid material through each of said successive nozzles being intermittently interrupted by said movement of said opening into and out oi' register with said nozzlespnieans,A including a rotor vshaft in housing, for driving said rotor; separate sets lof vanes on said shaft and on said housing, respectively, for agitating, mixing, and homogenizing said iluid as it is impelled through said housing to said valving rotor chamber; and, means for axially moving said rotor shaft to selectively position said valving rotor relative to said sets oi.' dispersion nozzles so as to admit fluid material to one or more of said sets of dispersion nozzles, at will.

8. A spray device comprising a, spray head having a central compartment of cylindrical contour from which nozzles lead tangentially to the exterior of the spray head, said compartment being open at its top and having a bearing well at its bottom concentric therewith, and said nozzles being arranged in separate superposed sets spaced from each other; a housing extending from said spray head and forming a passage leading to said compartment, said housing having a nozzle at its other end through which iluid material is adapted to be supplied to said rotor; a rotor shaft concentric with said housing journalied at its one end in said Weil for rotation and axial translation therein and journalled ad` jacent its other end in said housing a cylindrical rotor in said compartment secured to said shaft and in close running relation to the wall of said compartment, said rotor having outlets in the circumferential periphery thereof and having an internal cavity providing passages for the ilow of fluid material therethrough from top to bottom and to said outlets; a prime mover for driving said shaft, coaxially connected thereto at its said other end; and. extensible means connecting said prime mover and said housing for axially translating said prime mover and shaft to selectively position said rotor in said compartment for discharging iluid material from its said openings through one or more of said sets of nozzles.

9. The device of claim 8 in which said sets of nozzles are ansularly disposed.

10. The device of claim 8 in which said passages in said rotor are arranged in a circular row concentric with said rotor.

l1. The device of claim 8 in which said cavity includes an annular compartment and in which said openings are sector shaped slots leading therefrom.

l2. The device of claim 8 in which said housing has a flared bore at its junction with said spray head.

i3. 'I'he device of claim 8 in which said housing has an annular mounted ilange at one end and an in1et nozzle integral with said nange.

HERMANN C. SCHU'IT.

References Cited in the le of this patent or the original patent UNITED STATES PATENTS Number Name Date 1,140,462 Johnson May 25, 1915 2,099,988 Norris Nov. 23, 1937 2,282,622 Toi-rence May 12, 1942

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