CA1212924A - Streamlined vortical inlet and outlet header for hydrocyclone banks - Google Patents

Abstract

ABSTRACT
A special form of fluid cyclone in which the velocity energy in the exit fluid is converted into exit pressure thus permitting the device to discharge to atmospheric pressure or a higher pressure while a vacuum may exit in the central core of the vortex. The result is achieved by use of a curved passage at the exit which starts as a coaxial space and grad-ually expands and turns outward to become a circular space between two disks. The removal of reject material to atmospheric pressure with a vacuum at the core may be achieved by limiting the restriction in cross-section of the bottom core such that the pressure is atmospheric and allow it to leave through a space between the end of the cone and a blunt shaped surface.
The above special form of fluid cyclone operates particularly well, because of reduced energy losses, when employed in a multiple arrangement in which the tangential velocity energy of fluid entering the barrel of the individual cyclone units is created by fluid flowing at larger radius such as to create a pattern of multiple vortex flow. The vortices are in a chamber providing a common inlet to a plurality of cyclone units with the vortices centering on the individual units. The special arrangement of fluid cyclones is in a geometry similar to that of a vortex trail with an even number of units of opposing vortex direction. The same type of arrangement; i.e.
having all of the units discharge into a common chamber, leads to further energy recovery in fluid leaving the fluid cyclones.

Description

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This is a divisional of Canadian ap~lication 405,038 filed 11 June 1982.
This invention relates to a special form of fluid cyclone in which the velocity energy in the exit fluid is converted into exit pressure thus permitting the device to discharge to atmospheric pressure or a higher pressure while a vacuum may exist in the central core of the vortex.
This invention also relates to a special arrangement for multiple fluid cyclones which operate with less energy due to recovery of the energy in the fluid as it leaves the device.
~he principles of the invention may be applicable, where the ~luid is a liquid or a gas and permits removal of solid or liquid particles of highex density than the main fluid.
Fluid cyclones and Hydroclones have been in use for ~ome time by the paper industry and metallurgical industry.
These devices are described in the textbook "Hydroclones"
written by D. Bradley and pu~lished by the Pergamon Press.
The most common form of Hydroclone i5 the straight conical design. Fluid enters by a tangential inle into a short cylindrical section. A vortex is created in the cylindrical section and a conical section below the cylindrical section as fluid 23 spirals in a path moving downward and inward, then upward in a helical path to an exit pipe co-axial with the cy~indrical section.
The centrifugal accelerationldue to rapid rotationof the ~luid, causes dense particles to be forced outward to the wall of the cylinder and cone.
The dense particles are transported in the slower moving boundary layer downward towards the apex of the cone where they leave ac a hollow cone spray. ~he high centrifugal force near the centre opens up a liquid free space which is referred to as a ., ?2~

vortex core. In the conical cylone,with free discharge o rejects to the abmosphere~this core is filled with air and a back pressure at the exit of the hydroclone is required to prevent air insuction.
In some designs the cylindrical section is much longer than in others. One design having a longer cylindrical ~ection is sold under the trade mark "Vorvac" which was d~si~ned to remove both dirt and gas ~imultaneously.' The general flow pattern is similar to that described for conical designs, but there is , 10 an additional dswnward moviny helical flow next to the core carrying froth or light ma,terial. This extra flow is obtained because of the use of a device at the exit which will be discu~sed later and referred ~o as a core trap. The reject flow from the Vorvac i~ usually to a vacuum tank and the entire fluid in the device is b~low atmospheric pres~ur~ in order to expand gas bubble~ so they can be taken out more readily.
Anothex known device sold under the trade mark "Vo~ject"
has a conventional type of fluid flow pattern, but the conical reduction at the bottom is used to turn back the main downward ~low toward~ the main fluid exit~ but not to limit discharge of reject flow. The boundary layex fluid containing the reject material is separated from the rest of the fluid nearer the centre by use of a core trap and it i~sues forth from a tangential exit under pressure. The rejection of material and prevention of air insuction in this type of design is not affected by outlet pressure. Rejection of material may be controlled by throttling of the reject stream and may also be limited by injectiOn of water to carry back fine material while removing coarser material.

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Various desiqns ~f fluid cyclones and other vortex separators are disolosed in the following United States Patents:

2,982,409 2,835,387 3,421,622 2,849,930 3,7B5,489 3,543,932 2,816,490 3,734,288 3,861,532 2,757,581 3,716,13~' 3,057,476 2,920,761 3,696,927 3,353,673 2,757,5~2 3,612,276 3,288,286 2,92~,693 3,101,313 The fluid leaving a fluid cyclone ha~ a very high tangential velocity about the central axis and quite a high axial velocity. In most designs this velocity energy becomes dissipated as turbulence in the exit piping.
A principal object of the present invention is to provide a modified design for the recovery of energy in the fluid which in previous designs was lost.
Where multiple small units are used they are usually assembled into some form of bank. The pa~t method used headers with individual connectors and more recent arrangements involve placing multlple units in~ank like systems. In both these systems nozzles or slots provide a throttling means to ensure distribution of the flow and a tangential entry velocity to the individual units.
A further object of the present invention is to provide a special arrangement for multiple cyclones which operate with less energy due to re~overy of the energy in fluid as it leaves the device.
A further object of the pre~ent invention is to provide -~ ~z~

a special arrangement for multiple cyclones which leads to reduced energy loss in creating the tan~ential velocity upon entering the fluid cyclones, thereby leaving more energy to be recovered on exit from each individual cyclone. In addition, the same special arrangement at the exit leads to more complete recovery of vel~city energy in fluid leaving the individual cyclones.
In keeping with the foregoing there is provided in accord-ance with one aspect of the present invention a fluid cyclone having an upper cylindrical end portion with inlet and outlet pa~sage~ tangential thereto, said outlat passage having an annular inlet in the cylindrical portion and coaxial therewith followed by an inner passage that gradually increases in area and diameter to the tangential outlet passage and a lower portion with a reject outlet in the lower end thereof.
In accordance with a further aspect of the present invention there is provided a header for a plurality of cyclones, said header having a passageway with a first inlet thereto and a plurality o outlets therefroM, said outlets being ~paced apart from one another downstream from said first inlet and providing inlets to respective ones of the plurality of cyclones; and deflector means in said passag~way to create vortices of flowing fluid at each of said plurality of outlets.
In accordance with a further aspect of the present invention t where a plurality of cylones are to be supplied with fluid, their tangential velocity may be pxovided by a multiple vortex pattern established between two plates with the centre of the multiple vortices centered on the axis of the cyclones. In a similar manner a reverse flow of vortices may be obtained in a separate space between two plates. This is best done witll an equal number of fluid cyclones half of which rotate clockwise and with inflow to the vortices between the parallel plates, and exit from the parallel plate on one side of the bank of cyclones whereas the other half of the fluid cyclones rotate in a counterclockwise direction and receive and discharge their flows to vortices between the plates from and to a channel on the other side of the bank of cyclones.
A set of deflector plates may be used on the inlet channels to the vortex space to insure proper formation of the vortex pattern by directing flow at the proper orientation towards the vortex about each cyclone~
The invention is illustrated by way of example in the accompanying drawings wherein:
Figure 1 is a~ elevational view of a typical cone type fluid cyclone;
Figure 2 is a similar view of a fluid cyclone provided i~ accordance with the present invention for recovery of velocity energy;
Figure 3 is a cross-sectional view taken along line 3 3 of Figure 2;
; ~igure 4 is a partial elevational sectional view illus-trating an alternate reject system;
Figure 5 is a horizontal sectional view taken along essentially 5-5 of Figure 6 of fl~id cyclones of conventional : type mounted in a special arrangement in accordance with the present invention;

Pigure 6 is a vertical section~l view of th multiple cyclone of Figure 5 taken along line 6-6 of Figure 5;
Figure 7 is a view similar to Figure 6 illustrating a raject system with cyclones of the type illustrated in Figure 2;
Figure 8 is an elevational view of a multi-cyclone provided in accordance with the present invention;
Figure 9 is an elevational view of the upper header for the multi-cyclone of Figure 8;
Figure 10 is a sectional view taken along a ~tepped sectional line 10-10 of Figure 11;
Figure 11 is a cross-sectional view taken along stepped sectional line 11-11 i~ Figure 9:
Fi~ure 12 is a cross-sectional view taken along stepped sectional line 12-12 in Figure 9;
Figure 13 is a cro~s-sectional view taken along sectional l~ne~ 13~13 in Figures 9 and 11; and Figure 14 is an enlarged cross-sectional view showing in detail one of the cyclones of the multi-cyclone unit.
Referring now i~ detail to the drawings, there i~
illu~trated in Figuxe 1 the mosk common fonm of hydrocyclone which is a straight conical design. Fluid enters by a tangential inlet 1~ into a short cyclindrical section 2. A vortex is created in the cylindrical section and a conical section 3 below the cylindrical section as fluid spir ls in a path moving downward and inward, then upward in a helical path to an exit pipe 4 co-axial with the cylindrical section. The centrifugal aoceleration due to rapid rotation of the fluid cau es dense particle~ to be forced outward to the wall of the cylinder and ~~ ~
4r cone. The dense particles are transported in a slower movin~
boundary layer downward toward the apex 5 of the cone where they leave as a hollow cone spray. The high centrifugal force near the center opens up a fluid ~ree space which is referred to as the vortex core when the fluid is a liquid. In the conical cyclone, with free discharge of rejects to atmosphere, this cone i5 filled with air and a back pressure at the exi~ of the hydrocy¢lone is re~uired to prevent air insuction.
The present invention is directed to reducing energy lo~ses caused by friction in fluid cyclones. In considering energy states in a fluid cyclone, at the inlet to the fluid cyclone the hydraulic ~nergy in the fluid is mostly pressure with some as velocity.
In the descending path, as the fluid spirals inward towards the smaller radius 9f exit, velocity increa~es roughly according to the relationship V~- krn~ If there were no friction n would have a value of 1, but because of friction n lies ~omewhere between -0.4 and -0.9 depending on design. In this region pres~ure energy goes down as velocity energy rises so that near the exit a major foxm of the energy is as velocity.
In a normal fluid cyclone this velocity energy is lost and the outl~t pressure i5 almost entirely ~rom the mean pressure energy in the outlet area.
If the velocity energy were to be completely converted into pre~sure energy at the exit and friction losses were zero in the cyclone it could operate at any flow theoreti~ally with no pressure drop. The velocity possible would be limited by the fact that the pressure could not fall below a vacuum of "

;2yr about 25 inche~ of mercury without having the space filled with water vapor. In practice, there are however lo~ses of hydraulic energy by fluid friction which means less recovery of energy than that applied.
The tangential velocity and hence centrifuge force in the vortex of a cyclone is related to the pressure differential between the inlet pressure and the average pressure s the fluid leave~ the central exit from the separating region. In the case of the conventional centrifuge with an air core, thi~ average pre~sure on exit of accepted fluid is somewhere between the core pre~sure and the exit pressure which hs to be above atmospheric pre~sure, whereas with a pressure recovery design, which ha~ a vacuum at the core, the average pre3sure will again be somewhere between the core pressure and that of the outlet, but much nearer the core pres~ure. Thus, the operation of the conventional and velocity reco~ery unit~ ~hown in the table below will have the same separation performance with inlet and outlet pressure ~hown compared in the table below.
PRESSURE ~P.S~I.

PRESSURE CONVENTIONAL _ VELOCITY RECOVERY
DIFFERENCE INLET OUTLET CORE INLET OUTLET CORE

High 50 5 0 40 10 -15 Low SO 5 0 ¦ 40 10 -15 A fluid cyclone with recovery of velocity energy is illustrated in Figure 2 wherein fluid to be treated enter~ by a tangential nozzle inlet 10 into a cyclindrical section 11. Here it mixes with fluid which has come up from below, but not z~

left the central exit opening 12. The mixture then follows a helical form of path downward to the cone 13 which is shown as a preferred curved form although a straight form would also function.
Any dense material is deposited by centrifugal force in the slower moving outer boundary layer. This layer travels quickly down the cone due to the differential pressure between differing radii resulting from centrifugal forces on the high speed fluid in the interior. The boundary layer material can be allowed to leave without the inner fluid by blocking the vortex with a blunt cone plate 14 while permitting the boundary layer fluid with its content o~ heavy material to leak away through a gap between the end 15 of the cone 13 and ~he blunt cone plate 14.
The main flow inside the boundary layer i5 turned back upward by the restriction of cone 13 and may either rejoin the downward stream in the cylindrical section 11 or leave by the central exit 12. The exit channel i~ anannular passage 16 be-tween an innercone 17 andan outercone 17A providing a space which leads gently outward and expand~ in area. In the design shown this passage curve~ outward however, although this is the preferred design as the expansion of the path is gentlest where velocity is highest, straight cones would also serve ~ome useful purpose.
The fluid leaves by tangential outlet 18.
The gradual expansio~ in the exit passage and gradual increase in its radius leads to a conversion of both the axial and tangential velocity into pressure energy. Thus the unit can di4charge to a much higher pressure than either at the core of _ g _ the vortex or the mean pressure in ~he exit stream. With discharge to atmospheric pressure there will be a partial vacuum at the core yet the design shown will permit the flow out of the reject end to occur to atmospheric pressure.
The blunk cone plate 14 blocks the vortex at the bottom and a central depre~sion 14A in the blunt cone plate 14 stabilize~
the core. The rejected fluid escaping from the gap 19 between cones 13 ~nd 14 entexs a cylindrical ~pace 20 the~ passe~
downward past the edge of the blunt cone plate 14 and spaced ap~rt support rods 21 into a space 22 between the bottom of the blunt con¢ plate 14 and a bottom plate 23. At thi~ point the reject fluid will have considerabl0 tangential velocity and pre~sure. As it pas~es the smaller radius towards a central exit 24 in plate 23, t~e tangential velocity will increase ~uch that a vortex will exist between plate 23 and the undex-side of the cone plate 14. The reject fluid will emerge finally through th~ central hole 24 as a hollow cone sprayO The pressure drop across the vortex on plate 23 will limit the rejection rate in selective fashion.
The pre~sure drop acros~ a vortex occur~ because of the centrifugal acceleration which acts on the mass of khe fluid.
The tangential velocity which causes this is dependent upon the initial tangential velocity of fluid enterinq the periphery of the vortex. If this fluid is a boundaxy layer fluid only, the velocity and hence throttling effect of the vortex will be low. If thi~ fluid contains higher velocity liquid from the inner portion in cone 13, then the velocity and throttling effect of the reject vortex will be high.

The design is hence selective in rejecting the boundary layer fluid only. The depth of the boundary layer will depend upon it~ viscosity and will increa~e it it contains a high content of dense solids. The pressure differential in the exit vortex is due to centrifugal force~ from the tangential velocity. Thus an increa~e in viscosity which will cause reduction in tangential velocity due to friction will thereby reduce the throttling effect of the vortex permitting a larger flow. This furthers the action of the reject sy~tem making it react automatically to varying loads of undesirable material in the fluid being treated.
Other arrangement~ may be made for removal of reject material. An extension of the cone, such a~ shown in Figure 4 a~ 25, will throttle re~ect material and limit discharge. if this is left open to the atmo~phere the pressure at the core of the cyclone must be also at atmospheric pressure. This may permit the fluid cyclone with velocity energy recovery to discharge to a pressure which may be useful in certain installat~ons. Where this is not the case it may be preferable for this type of reject control to discharge rejects to a vacuum receiver 26.
In instances where the quantity of unde~irable ~olids is extremely low they may be collected in a closed receiver.
Thus the space between the orifice plate 23 (Figure 2) and the bottom of the cone plate 14 may be replaced with a receiving chamber having a suitable mechanism for dumping the collected solids.
It is a known fact that smaller cyclones can remove , .~

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finer particles than larger units. Experiments conducted by the applicant ~avealso revealed that a smaller unit for the same design capacity has less loss of hydraulic energy by friction and hence more recoverable hydraulic energy. The applicant has also established through experiments that the simple tangential entry into a cylinder results in a great deal of loss of hydraulic energy and generation of turbulence.
These studies have resulted in multiple arrangements of cyclone units by the applicant and which are illustrated in Figures 5 to 14. In the multiple units, multiple vortices are created directly in a header system in a stable arrangement. The arrangement may be considered identical to that of the stable pattern of vortex eddies which are created when a stream of ~luid passes a fixed object and is known as a vortex trail.
Vortices of opposite rotational sense progress in two lines.
The ~pacing of the two lines normally would be 0.2806 times the spacing of individual vortices at each trail.
Referring to Figures 5 and 6 there i8 illustrated six cyclone units 4OA, 40B, 40C, 4OD, 4OE and 4OF (only three appear in Figure 6~ that are of conventional design but provided with a novel inlet and outlet means. The inflow fluid to the - cyclone units is from a common chamber 42 and the outflow into a common chamber 44. Chambers 42 and 44 are separate from one another and provided by spaced apart flat parallel plates 45, 46 and 47 interconnected by side walls and ena walls. The chambers have respective opposite end walls 48 and 49, each of whicA have curved wall portions 50 and 51 interiorly of the chambers, such portions being preferably of spiral shape.

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Cyclone units 40A, 40C and 40G are spaced apart from one another in a first row and cyclone units 40B, 40D and 40F are spaced apart from one another in the second row. The first and second rows are spaced apart from another and the cyclone units are staggered as best seen from Figure 5.
Cyclone units 40A, 40C and 40G have fluid rotation which appear from top view to rotate clockwise as indicated by arrows 53, 54 and 55 whereas units 40B, 40D and 40F have fluid rotation which appears from the top view to rotate coun$erclockwise as indicated by arrows 56, 57 and 58. The row of counter-rotating units is displaced by half the distance between units in the row direction and by approximately ~28 times the distance between units sideways, thus placing the unitæ in the pattern normally observed in a vortex trail. In this pattern, counter-rotating vortices are closest to each other and there is no frictional shear between them. The individual cyclone units acquire their fluid flow, not from individual tangential inlets, but by a general pattern of multiple vortices which i~ established in the space 42 between the parallel plates 45 and 46. The pattern of flow is established by two streams of con~tant velocity admitted by two chann~ls 59, one to feed ~ fluid into clockwise vortices 53, 54 and 55 and the other into counterclockwi~e vortices 56, 57 and 58. Fluid is diverted from the channels 59 at the appropriate angle and po~ition to form the proper spiral vortex pattern by deflection plate~
60 and the spiral containment end walls 50 and 51. The two feed channels 59 are joined by a passage 61 having an inlet 62 thereto through which the entering fluid is fed.

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Fluid which enters the barrel of the cyclones leaves the cyclones by respective exit pipes 63 with a high rotational velocity into the space 44 between the plates 46 and 47.
Although much of the rotational velocity is lost with the abrupt corner as shown, there will be reverse vortex flow in the space 44 in the tangential matrix in a similar sense to that in space 42 but with outward fluid flow movement. The fluid from the space 44 flows by way of two channels 64 interconnected by a passage 65 and is discharqed throuqh a cor~on outlet similar to inlet 62 illustrated in Fi~ure 5.
The heavy material rejected at the bottom exit of the fluid cyclones i~ ~hown a~ being collected in a pan 66 and discharged through an exit passage 67.
The ambodiment illustrated in Figure 7 is simila~ to that illustrated in Figure~ 5 and 6 and consists of a plurality of cyclone units 70 which are of the energy recovery type of Figure 2. The energy recovery cyclones are arranged in the t~pe of arrangement of Figure 5 with the pattern of spiral vortices of a similar type created in the ~pace between 2D flat plates definin~ the chambers. The cyclones have conical and bottom end design 71 which is similar to that shown in Figure 2 and an annular opening 72 fsr outflow of material from the cyclone. The annular outlet 72 leads to an expanding annular space 73 which in turn leads to space between the plates defining chamber 74. In this latter space the reverse spiral flow pattern described above with reference to Figures 5 and 6 occurs with fluid being collected by a pair of channels 75, only one of which is shown and which are interconnected by a pas~age 76 having an outlet there~rom ~not shown) similar to inlet 62 illustrated and described with reference to Figure 5.
Reject materials are collected in a pan 77 and taken away by a pipe or other passage means 78.
Material to the respertive cyclone units 70 is from a chamber 79 common to all of the units and having a pair of inlet passage means ~0 (only one of which ;.s shown) similar to the pas~a~es 59 described and illustrated with reference to Figure 5. The pair of pa~sages 80 are interconnected by a passage 8l. having an inlet thereto (not shown) corresponding to inlet 62 illustrated and described with reference to F.igure 5.
Referring to Figures 8 to 14 inclusive, there is illu~trated in more detail a practical embodiment of a multi-cy d one unit consi~ting of a plurality of individual cyclone units 100 having an inlet and outlet header system 200 on the upper end and a reject box 300 on the lower end, all of which are mounted on a supporting structure 400O The suppor~ing fxame 2~ consists of four vertical posts 401 rigidly connected by way of coupling members 402 to a horizontally disposed support plate 403. The reject box 300 is al50 rigidly connected to the legs 401 by way of bracket members 301~ further rigidifying the entire structure.
The header 200 has an inlet 201 for fluids to he treated and an outlet 20~ Details of the header 200 are illus rated in Figures 9 to 13 inclusive and reference will now be made thereto. The header 200 is a rigid assembly having four 2~

sockets 203 for receiving the upper ends of the frame posts 401, thereby mounting the header on the rame. Suitable locking means, for example set screws or the like, may be utilizea in anchoring the headex to the posts. The header 200 has a chamber 204 in which there is established a pattern of vortex flow Ruch that the chamber serves as a common inlet for all of the cyclone units. Similarly there is a chamber 205 common to all of the individual cyclone units for the outflow o~ fluid from the cyclones. The inlet chamber 204 is defined by a central plate 206 and a lower plate 207 together with side plates 208 and 209. The outlet chamber is defined by the central plate 206 and upper plate 210 spaced therefrom and the side plates 208 and 209.
In referring to Figure 11 thexe is located in ~he inlet chamber 204, a partition wall 212 that divides the inflowing fluid into two passages designated respectively 213 and 21~.
In the respective passages are diverter plates 215 and 216 secured to the central plate 206 and projecting downwardly therefrom toward the lower wall of the inlet manifold but spaced thersfrom. The diverter plates 215 and 216 direct the inflowing fluid to form spiral vortices about the inlets of respective individual cyclone units lOOA and lOOB. Fluid flowing below the diverter plates 215 and 216 is directed to form spiral vortices about the respective individual cyclone unit~ lOOC and lOOD. The curvedend wall portions 221, 222, 223 and 224 serve as containment walls for the vortices at respective cyclone units lOOA, lOOB, lOOC and lOOD
and as previously mentioned are preferably spirally shaped.

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The passages in outlet chamber 205 are shown in Figure 12 which is a section taken along stepped line 12-12 in Figure 9. The outlet from the individual cyclone units lOOA, lOOB, lOOC
and lOOD i9 into chamber 205 and fluid flow therefrom is divided by partition wall 217 into passages 218 and 219 connected by way of passage 220 to the outlet 202.
A cross-section of an individual cyclone unit is illus-trated in Figure 14 and includes an upper cylindrical portion 101 followed by a lower tapered conical sectionlO2. Inflow of fluid to be treated through chamber 204 enters the cyclone from the centre of the spiral vortex in said manifold by annular inlet passage 1030 Outflow from the cyclone is through an annular pa~sage 104, gradually increasing in size to the outlet chamber 205 where lt spirals outward. The passage 104 is provided by truncated conical member 105 mounted on the inter-mediate plate 206 and a further conical member 106 projecting thereinto and mounted on the upper plate 210 by a plurali~y of bolt~ 107. The cylindrical portion 101 and tapered lower end portion 102 may be a single unit or, alternatively, separate units as illustrated, the cylindrical portion being provided by a short length of sleeve abutting at one end the lower mani-fold plate 207 and at the other end a flange on the tapered cone 102. A plurality of screws lU8 r threaded in the frame plate 403, press against an annular bearing ring 109 abutting the flange on member 102 and presses the cylindrical sleeve 101 against the manifold~ O-ring seals 110 are provided to seal the joints.

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The reject box 300 i~ mounted on the ~rame posts 401 at the lower reject outlet end of the cyclone. Between the reject box and mounted on the lower end of th~ conical portion are upper and lower plates 120 and 121 interconnected by a plurality of bolt and nut units 122 and held in ~paced apart relation by a short sleeve 1230 The lower end of the cone 102 is open as indicated at 112 and spaced therebelow is a cone plate 125. The cone plate 125 is mounted on the plate 120 by a plurality of machine screws 126 spaced apart from one another circumferentially around the cone plate. The cone plate i~ held in suitable spaced relation from plate 120 by spacer~ 127. Rejects from the cyclone follow the path in-dicated by ~he arrow A and discharge into the reject header box 300 by way of an aperture 128 in the lower plate 121.
Cyclone~ of the foregoing design are basically intended for use with water as the working fluido The present design, however, is also deemed applicable when using gas as the work-ing fluid; for example, treating gases from furnaces to remove fly ash and smoke.
There would, of course, be no pha~e discontinuity with ga~ in the cyclone, but the core pre~sure could al~o become ~u~atmospheric with a de~ign with pressure recovery. If the core pressure was low enough the gas near the core would expand thus increa~ing the velocity and become cold because of adiabatic expansion. The velocity of gases and hence the centrifugal force will be very much hiyher due to it~ low~r density with an upper limit at the velocity of sound or approx-imately 1000 ft/~econdO ~his compares to a maximum theoretical pos~ible velocity with water as the fluid, with 10 p.s.i. inlet and vacuum core of 60 ft. per second. The cantrifugal accel-eration3 at a radius of 1/2 inch with these tangential velocities would be 2683 time~ that of gravi~y for the water and 745,341 times that of gravity for the ~as at the velocity of sound.
In practice neither of these maximum velocities will be achieved because of friction in both devices. Gas cyclones are usually employed with only a few inches water gauge as a pressure differential. The velocity of sound can be achieved with 10 p.s.i. o~ air pressure. Atmospheric pressure is in excess of this so that very low friction loss and complete pressure recovery could achieve close to the velocity of sound in the gas near the core with a very low pres~ure differential across the unit.
A small multi-cyclone unit as described in the foregoing has been teste~ by the applicant for comparison in operability with air as opposed to water as the working fluid. In testing the unit to txeat air, a fan was used to suck the air through the unit. The comparison makes the assumption that friction losses are proportional to velocity head whether one is dealing with air or water which is approximately true at very high Reynold~ number. The following table shows comparative operation of the ~ystem on water and air ~f~

CONPAP.ISON 3" MULTICYLONE 4 UNITS

Water Air Inlet Pressure 10 p.s.i. Atmospheric Outlet Pre~sure 0 p.~ 1" Water Gauge F1GW150 US gallon/min 62 cubic ft/min Mean Gravities 315 97 5 Mean Pressure at Outlet 6" Hg Vacuum -1.2" Water gauge Core Pressure28" ~ligh Vacuum10" Hg Vacuum?

In practice one would use much larger and more numerous cyclones to handle air at the l~w fan pressures used ~/ in the test. ~ydraulic capacities are roughly proportional to the square root of the applied pressure differential. Mean gravities will be roughly proportional to the pressure differential. The mean pressure shown is in the fluid leaving the interior of the unit. ~he very center of the vortex will have a much lower pressure which in the case o~ water is filled with wa.ter vapour. The core condition with air is difficult to estimate due to expansion of the gas resulting in reduced d~nsity and temperature. The tests conducted, however, do establish applicability in the use of the multiple arrangement 20 for not only liquids but gases.

Claims (15)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A header for a plurality of cyclones, said header having a first chamber with an inlet thereto and a plurality of outlets therefrom, said outlets being spaced apart from one another downstream from said inlet and providing inlets to respective ones of a plurality of cyclones; and deflector means in said passageway to create a stable pattern of multiple vortices of flowing fluid in said chamber, said vortices being in contact with each other and consisting of a series of counter rotating pairs located such that there is a vortex at each of said plurality of outlets.

2. A header as defined in claim 1 wherein said outlets are arranged one after the other downstream from the inlet along two lines and wherein the outlets in one line are staggered downstream relative to the outlets in the other line.

3. A device for directing fluid to and from a plurality of fluid cyclones comprising: first and second chambers separated from one another and providing respectively a common inlet to and common outlet from a plurality of individual cyclone units spaced apart from one another, an inlet to said first chamber, deflector means in said first chamber for establishing a stable pattern of a multiplicity of vortices in fluid flowing into said first chamber from the inlet thereto, said vortices being in contact with one another and consisting of a series of counter rotating pairs, said vortices being equal in number to the number of individual cyclone units and at the respective locations thereof and an outlet from said second chamber.

4. A device as defined in claim 3 wherein said cyclone units are arranged in spaced apart rows with the cyclone units in one row offset in the direction of fluid flow with respect to the cyclone units in an adjacent row.

5. A device as defined in claim 4 wherein the vortices in the respective rows rotate in directions opposite to one another.

6. A device as defined in claims 3, 4 or 5, wherein the inlet to said first chamber comprises two parallel flow paths defined by respective first and second passageways, said flow paths being along opposite sides of the chamber and wherein said deflector means project partially into said passageways.

7. A cyclone arrangement comprising a plurality of individual cyclone units spaced apart from one another, header means detachably secured to the respective cyclone units for directing a flowing fluid to each of said plurality of fluid cyclones, said header means having a first chamber in fluid flow communication with respective ones of said cyclone units, deflector means in said first chamber for establishing a stable pattern of a multiplicity of vortices in fluid flowing in said first chamber, said vortices being in contact with each other and consisting of a series of counter-rotating pairs, said vortices being equal in number to individual cyclone units and at the respective locations thereof and outlet means from said plurality of cyclone units.

8. A cyclone arrangement as defined in claim 7 wherein said cyclone units are arranged in spaced apart rows with the cyclone units in one row offset in the direction of fluid flow with respect to the cyclone units in an adjacent row.

9. In a cyclone system a plurality of individual cyclone units spaced apart from one another and a header attached to the respective cyclone units for supplying fluids thereto, said header comprising a first chamber providing a fluid space common to all of said cyclone units, fluid flow deflector means in said first chamber arranged such that the tangential velocity of fluid entering said cyclone units is provided by a stable pattern of multiple vortex flow in said fluid space common to all said cyclone units, said multiple vortex flow comprising a series of counter-rotating vortices in contact with one another, one being located at each of the respective cyclone units.

10. In a cyclone system including a plurality of individual cyclone units, an arrangement for supplying fluids to said fluid cyclone units comprising a first chamber providing a fluid space common to all of said cyclone units, fluid flow deflector means in said chamber arranged such that the tangential velocity of fluid entering said cyclone units is provided by a pattern of multiple vortex flow in said fluid space common to all said cyclone units, and an arrangement for collecting fluid from said plurality of fluid cyclone units such that the swirling motion in the fluid leaving the cyclone units establishes a pattern of multiple vortices in a common space constituting a second chamber separate from said first chamber.

11. In a cyclone system including a plurality of individual cyclone units, an arrangement for supplying fluids to said fluid cyclone units comprising a first cham-ber defined by a space between a first plate and a second plate providing a fluid space common to all of said cyclone units, fluid flow deflector means in said chamber arranged such that the tangential velocity of fluid entering said cyclone units is provided by a pattern of multiple vortex flow in said fluid space common to all said cyclone units, and an arrangement for collecting fluid from said plurality of fluid cyclone units such that the swirling motion in the fluid leaving the cyclone units established a pattern of multiple vortices in a common space between said second plate and a third plate constituting a second chamber separate from said first chamber.

12. In a cyclone system for feeding fluid as well as removing fluid from multiple fluid cyclones as described in claim 11 in which pairs of conduits are placed outside and parallel to the adjacent counter rotating rows of cyclones, one of each pair being used for a given direction of vortex rotation.

13. In a cyclone system as defined in claim 5 in which the fluid cyclone with fluid rotation in a clockwise sense are spaced evenly in a first row whereas the equal number of fluid cyclones with fluid rotation in a counterclockwise sense are given the same spacing in a second parallel row displaced laterally by approximately 0.28 times the spacing of cyclone units in a row and in the row direction 0.5 times the spacing of the cyclone units in a row.

14. In a cyclone system as defined in claim 9 in which the number of cyclones is even with equal number with fluid rotating in opposing directions each being positioned adjacent to one or more cyclones with opposing direction of rotation.

15. In a cyclone system for feeding fluid as well as removing fluid from multiple fluid cyclones as described in claim 14 in which pairs of conduits are placed outside and parallel to the adjacent counter rotating rows of cyclones, in a plane normal to the vortex axis, to serve a plurality of vortices, one of each pair being used for a given direction of vortex rotation.