US3199271A

US3199271A - Apparatus for separating flowing media of respectively different mass inertia

Info

Publication number: US3199271A
Application number: US132386A
Authority: US
Inventors: Schmidt Karl Rudolf; Ochlrich Karl-Heinz
Original assignee: Siemens AG
Current assignee: Siemens Schuckertwerke AG; Siemens AG
Priority date: 1958-08-22
Filing date: 1961-08-18
Publication date: 1965-08-10
Anticipated expiration: 1982-08-10
Also published as: GB960270A; DE1262234B; CH395935A; CH382716A

Description

10, 1955 K. R. SCHMIDT ETAL 3,199,271

APPARATUS FOR SEPARATING FLOWING MEDIA OF RESPECTIVELY DIFFERENT MASS INERTIA Flled Aug 18, 1961 2 Sheets-Sheet 1 1965 K. R. SCHMIDT ETAL 3,199,271

APPARATUS FOR SEPARATING- FLOWING MEDIA OF RESPECTIVELY DIFFERENT mass INERTIA Filed Aug. 18, 1961 2 Sheets-Sheet 2 NOZZLE WITH PRISMATIC CROSS SECTION FIG. 5

United States Patent 0 Cur relates to apparatus that are medicated upon the production of relative forces, particularly Coriolis forces, in a flow of media of respectively different mass inertia, par ularly for the purpose of separ ng dust from gas, but also for other purposes such as mixing pulverulent substances with gaseous substances. In more particular aspect, our invention relates to apparatus based upon the fluid-low principles set forth in the copending application Serial No. 835,886 of Gehlrich et al., filed August 25, 13 59 and assigned to the assignee of the present invention.

For a further understanding of the principles of fluid mechanics involved various ways in which they may be applied, reference may also be had to copending applications Serial No. 24,391 of Oehlrich et al., filed April 25, 1960, Serial No. 862,579 or Oehlrich et al., filed eceinber 29, i959, and Serial No. 98,604 of Oehlrich, filed March 27', 1961, all assigned to the assignee of the present invention. erence may also be had to the Explanator Append portion of the specification of application ial No. 128,431, filed August 1, 1961 of Karl Rucl if Schmidt Karl-Heinz @ehlrich, entitled Nuclear Reactor and Method of Processing, Entrainirig, Handling and Moving Fissionable Ma erial, and assigned to the assignee of the present invention.

According to these principles apparatus, a potential how is e ed a fluid medium, and this potential how is converted 'nto a secondary rotational flow that l relation to and in the same sense as the pri .3; flow, the conversion being effected with the aid of a flow profile which acts as a solid or rough ground and win e symmetry axis extends in the flow direction of the medi' Such a primary, potential flow may be excited by s r or guiding devices which rotate in a pl. 1: cular to the flow direction of the media, or it may be excited by an auxiliary medium, particularly secondary air which is blown into the main flow in inclined tangential direction and opposed to the primary flow direction of the media. The present invention particularly relates to the last-mentioned excitation of the secondary air injected into the 1 ose of dust separation, the 'l rlov, located outside of a e prior to mixing or batiie zone such as represented by a dust ring. As disclosed in the above-mentioned earlier cop-ending s, the desired rotational flow can be excited ctrng the secondary dr with the aid of slots, chanotlier nozzle terms which, for distinction from ly the primary flow of dust-laden air or gas, are hereinfter called secondary-air nozzles. The

present invention concerns itself particularly with th de ti and operation of the secondary-air nozzles for exciting the circulating flow that comprises a component peter. 31 how and a component rotational how, and has for its object to greatly improve the efiicacy of these secondary-air nozzles.

It is, therefore, object of the present invention to provide means for producing turbulence in jet streams eject-ed from nozzles, and particularly for producing corrical flow patterns with marginal turbulence zones.

it is anot or object of the invention to provide an apparatus for the purposes of handling, combining or separating pulverulent materials in a carrier fluid by injecting a secondary fluid flow tangential to and having a component opposition to a primary fiow path, and to make the secondary how effective for these purposes independent of the angular position of the secondary injection.

it is a further object of the invention to provide adjustle thro ing means for controlling the flow of secondry gases introduced tangentially into a primary gas flow ected gaseous how by providing a rough surface on which the gaseous flow impinges.

The invention will be further described with reference to the emb .Jits of apparatus according to the invened by way of examrrle on the accompanying It is another object of the invention to create turbulence tion iliust gs in which:

i is a schematic illustration of an apparatus for -ust from smoke-gas.

3 and 4 illustrate schematically and in axial "ee respective secondary-air nozzles provided with a rectangular, slit-type nozzle according to the invention.

Flu. 6 is a sectional view of the same nozzle, the view taken along the line VlVI in FIG. 5.

7 is a top view of a slit nozzle having a cross section of trapezoidal shape; and

FIG. 8 shows an enlarged view of a thorn according to PEG. 3 with a bore therethrough.

FIG. 1 illustrates schematically an apparatus for removal of dust from smoke gas. Dust-laden smoke-gas en a primary flow P into the processing cont r throu h an inlet duct 1532. A circulating flow re container through respective tangential ducts Ill?) which are downwardly inclined. The resulting ringaped flow of gas constitutes a rough ground of the flow at the bottom of the vessel as shown (FIG. By co rtrolling the primary and secondary ilow, the same :5 neral principles may be used not only for dustseparation, as shown in Fit 1, but also for mixing, demixing, combining, de-combining and handling of various media, as further described in the above-mentioned copending applications.

The devices illustrated in FIGS. 26 may be inserted, for nple, at res in NS. for a more effective secone ary flow.

The secondary-air nozzles for injection at l d-3; as heretofore proposed are smooth in their interior. As exained in the above-mentioned copending application Scrial No. 835,886, the effect of the secondary-air flow can iy augmented if the secondary air possesses a high circa-.. ory turbulence. For that reason, the iniection of the secondary air is preferably effected over a sharp edge or through a rotating-vane device or by means of a combination of such devices.

A turbulence in the injected secondary air produces fluctuation pulses transverse to the main flow direction P of the gas and thereby produces also an energy transmissi n per; dicular to this flow direction. Since the main travel direction a of the secondary-air current, be ing injected in an inclined-tangential direction, is opposed and in ed to the raw-gas current P, the fluctuation velocities in the intermediate boundary layer between these stream side of this body may be roughened. rality of marginal turbulence zones are to be produced two currents, i.e.' in" the so-called boundary zone or mixing zone, produce additional virtual shearing tensions which are approximately proportional to the fluctuations in speed.

- Such a turbulent flow. is of essential significanceto the effectiveness of the secondary air because the entire efficiency of excitation and, in the case of dust separation the overall degree of the dust separation, are nearly independent of the angular position of the secondary-air nozzles if the secondary-air how is given marginal turbulences, this having been ascertained by comprehensive tests.

According to our invention, therefore, these phenomena are taken advantage of by providing the secondary-air nozzles, for excitation of the potential flow, with turbulence-producing means, preferably protuberances, serra- :tions, teeth or other roughness. Such a nozzle injects the secondary air in the form of a conical current into the main gas flow P which, in the case of dust separation, is laden with the dust to be separated. The injected secondary air then exhibits marginal turbulence zones and form individual jet streams at the conical peripheral surface zone of the flow. In the case of dust separation, the

lower, turbulent edge or end portion of such a turbulence cone suffices at a slight positive pressure of the secondary current to removethe dust downwardly.

tiveness or dust separation.

The turbulence-producing means according to the invention may be arranged in nozzles of round and/or prismatic or'rectangular cross section. Rectangular nozzles, when given a slit-type design or with a particular sub-division, afford a favorable arrangement of the turbulence-producing means while simultaneously maintaining a high injection pressure. Such a rectangular nozzle,

also called slit nozzle may be sub-divided by guide sheets for parallel guidance of the air. The narrow sides of the slit nozzle may be curved toward each other in order to obtain a contraction of the jet. 7

Roughness may be provided at the inner side of the nozzle exit portion, on the face impinged by the air being supplied. The roughness of the surface may be teeth,

serrations,screw threads or grating having raised patterns. If the nozzle possesses an adjustably mounted throttle body whose displacement permits adjusting the quantity of secondary air and the nozzle pressure, then the up- If a plusimultaneously with one and the same nozzle, then a thorn designed approximately as a flow-guiding or air-foil body is preferably inserted into the nozzle, this thorn being roughened on its surface. The thorn itself may also be provided with a central bore to act as an additional nozzle.

According to another feature of our invention, vane bodies are arranged within the nozzle at a location ahead of the air-outlet opening which elfect a pre-excitation of the secondary air flow in such a manner as to impress a potential flow upon the injected secondary air and placing the air in the rotary-turbulence nozzle in rotation. This further improves the desired turbulent action.

These features will be described below in greater detail,

port 1a with a threaded stud 1b serving for attachment of the nozzle to a suitable mounting structure or to the vessel 101. Also secured to the carrier in is a piston 3 in coaxial relation to the tubular structure 1. The secondary air is supplied through a lateral tube 6 in an inclined direction with respect to the nozzle tube 1. The piston 3 has an inclined front surface 2 provided with numerous protuberances or grooves to provide for roughness relative to the flow of secondary air. Similar roughness is provided at 4 onthe inner side walls of the tubular member 1. For further increasing the turbulenceproducin action, aprojection 5' with a sharp edge is located inside the nozzle within the path of the second ary air from 6.

The rough front surface 2 of the adjustable throttle piston 3 and the roughness at 4 on the inner side of the nozzle outlet effect the formation of a conical jet 7 with a multitude of turbulence zones at the boundaries thereof. That is, the particles of the secondary-air current, aside from flowing in the main (secondary flow) direction indicated in FIGS. 1, 2 and 4 by an arrow'a, also rotate in the plane of illustration, as schematically indicated by the arrows b (FIG. 2). The particles are subjected to a braking action at the roughened surfaces of the nozzle so that'the particle speed becomes reduced at these places, whereas the speed at the particle side facing the inner core of the current becomes increased. This results in stabilization of the secondary-air jet flow stream as to direction and shape.

According to a further feature, illustrated in FIG. 2 and also in the embodiment shown in P16. 3, a potential flow is impressed'upon the secondary air by vane bodies 15. In this manner, the resulting rotational motion further increases the turbulence of the flow. in all other respects, the nozzle according to FIG. 3 corresponds to that of FIG. 2, the same components be ng designed by the same reference numerals, respectively.

The nozzle shown in FIG. 3 is provided with an axially displaceable throttle piston 35 with a rough front surface 2 impinged upon by the incoming gases from 6, the tubular nozzle member 1 being also provided with roughness at 4 near the nozzle outlet. Also provided is a sharp edge at 5 for increasing the turbulence-producing action.

The secondary air injected through the angular tube 6 passes out of the nozzle in form of a turbulence cone 7, the turbulence being due to the roughness 2 at the piston 3 and the roughness 4 at the nozzle outlet. Inserted into the displaceable throttle piston 3 is a thorn 8 which has a roughened outer surface and which forms in the air flow an internal turbulence cone 9 within the cone 7. The thorn 8 may be given a bore 8a (FIG. 8) to make it hollow and to thus produce a third turbulence cone within cones 7 and 9. The provision of such additional marginal turbulence zones greatly increases the degree of separation, particularly with respect to the finest fractions or grain sizes of dust.

An angular injection of the secondary air by means of the angularly mounted tube 6 as in FIGS. 2 and 3 is preferably provided if the nozzle is to simultaneously act as a throttle member. However, as shown in FIG. 4, the air can also be injected in the direction of the main jet a through the nozzle tube 1 which in the abovedescribed embodiments of FIGS. 2 and 3 is substantially filled by the piston 3. The thorn 8, according to FIG. 4, can then befastened in the nozzle tube 1 by spacer structures or bridging members such as 21 or 21a.

Turbulence nozzles of greater diameter can be provided with an additional tubular insert 20, as further shown in FIG. 4. The inner surface of the insert 20 is roughened in the above-described manner. Fastened to a bridge or spacer member 21!. extending across the insert'ZtP are the thorn 8 and another tubular insert 22. The thorn 8 has a roughened surface, and both the inner and outer surfaces of the tubular insert 22 are roughened. In this manner, a'further cone 23 is formed in addition to the turbulence cones 7 and 9.

FIGS. 5 and 6 illustrate a rectangular nozzle (slit nozzle) in the side of a vessel '1 of diameter D. FIG. 7

is a modification of the structure of FIG. 5 but with the sides 17 inclined instead of parallel. The nozzle conduit is provided on its longitudinal inner sides with turbulence-producing means 11 and 12. These turbulence-producing means 11 and 12 are rough surfaces, such as grating patterns, and are spaced from each other a relatively small distance d, so that, with a high injection pressure, a great multiplicity of turbulence zones will result because of the numerous variouslyoriented members of each pattern 11, 12. The slit nozzle is provided with transverse guide sheets 16 Within the conduit 10, and the narrow sides 17 at the outlet of the slit nozzle are bent so as to curve toward each other.

An additional augmentation of the turbulence can also be obtained by injection of a pulsating or intermittent air current from a blower or other source S (PEG. 6) and a valve V rotated by motor M to open periodically.

The invention is applicable to advantage not only for separation of dust or other fineranular substances from gaseous media, but also in other cases Where turbulent fluid flows are to be produced, for example for fuel injection in cyclone-firing systems, and in the corner-type firing systems of combustion chambers.

It will be obvious to those skilled in the art, upon a study of this disclosure, that our invention in amend able to various other modifications and hence can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of our invention and within the scope of the claims annexed hereto.

We claim:

1. Apparatus for handling materials entrainable in a carrier fluid for the purpose of separating out said materials from said fluid, comprising a vessel having a wall, means defining an inlet and an outlet for the passage of fluid through the vessel and defining a primary-flow axis for the carrier fluid in which said materials are entrained, agitating means for imparting to the primary flow in said vessel a circulatory motion, said agitating means comprising nozzle means for injecting fluid along respective helical flow paths into said vessel in a direction substantially tangential to the primary flow and inclined toward the primary flow axis and having a component in opposition to said primary flow so that said agitating means superimpose upon said primary flow in said vessel a circulatory secondary flow coaxial with said primary flow and forming in said vessel a vortex sink and a vortex source spaced from each other along said primary flow axis; said nozzle means terminating flush with the wall of the vessel and being provided with means defining protuberances for producing turbulence in the fluid injected into said vessel from said nozzle means, and means for collecting the separated materials in the lower part of the vessel.

2. In an apparatus according to claim 1, said means for producing turbulence comprising a rough surface within said nozzle means and placed along the path of the fluid passing through said nozzle means.

3. In an apparatus according to claim 1, said nozzle means having a prismatic cross section.

4. In an apparatus according to claim 1, said means for producing turbulence comprising a rough surface having a serrated cross section and disposed within said nozzle means along the path of the fluid passing through said nozzle means.

5. In an apparatus according to claim 1, said nozzle means being provided with guide means on the inner surface of the outlet thereof for guiding the fluid injected into said vessel space in said circulatory secondary flow coaxial with said primary flow.

6. in an apparatus according to claim 1, said means for producing turbulence comprising projections having sharp edges and disposed within said nozzle means.

7. in an apparatus according to claim 1, a throttle piston adjustably mounted Within said nozzle means and having a front face arranged in the path of and to be impinged upon by the fluid passing through said nozzle means, said front face having a rough surface to form at least part of said means for producing turbulence in the fluid injected into said vessel space from said nozzle means.

8. In an apparatus according to claim 1, said means for producing turbulence comprising a thorn member having a rough surface disposed within said nozzle means.

9. In an apparatus according to claim 8, said thorn member comprising a hollow tubular body.

References Cited by the Examiner UNITED STATES PATENTS 1,070,800 8/13 Gross 55-263 1,505,743 8/24 Stebbins 55459 1,534,833 4/25 Binks 55464 2,153,026 4/39 Ringius 55459 2,252,581 8/41 Saint-Jacques 55459 2,378,600 6/45 Tongeren 55459 2,437,294- 3/48 Dalin 55459 2,650,675 9/53 Ycllott 5583 2,786,547 1/59 McCartney 55426 2,869,677 1/59 Yellott et al. 55426 3,019,780 2/62 Nuding 55459 FOREIGN PATENTS 525,985 2/54 Belgium.

477,204 6/29 Germany.

354,608- 8/31 Great Britain.

752,353 7/56 Great Britain.

HARRY B. THORNTON, Primary Examiner. HERBERT L. MARTIN, Examiner.

Claims

1. APPARATUS FOR HANDLING MATERIALS ENTRAINABLE IN A CARRIER FLUID FOR THE PURPOSE OF SEPARATING OUT SAID MATERIALS FROM SAID FLUID, COMPRISNG A VESSEL HAVING A WALL MEANS DEFINING AN INLET AND AN OUTLET FOR THE PASSAGE OF FLUID THROUGH THE VESSEL AND DEFINING A PRIMARY-FLOW AXIS FOR THE CARRIER FLUID IN WHICH SAID MATERIALS ARE ENTRAINED, AGITATING MEANS FOR IMPARTING TO THE PRIMARY FLOW IN SAID VESSEL A CIRCULATORY MOTION, SAID AGITATING MEANS COMPRISING NOZZLE MEANS FOR INJECTING FLUID ALONG RESPECTIVE HELICAL FLOW PATHS INTO SAID VESSEL IN A DIRECTION SUBSTANTIALLY TANGENTIAL TO THE PRIMARY FLOW AND INCLINED TOWARD THE PRIMARY FLOW AXIS AND HAVING A COMPONENT IN OPPOSITION TO SAID PRIMARY FLOW SO THAT SAID AGITATING MEANS SUPERIMPOSE UPON SAID PRIMARY FLOW IN SAID VESSEL A CIRCULATORY SECONDARY FLOW COAXIAL WITH SAID PRIMARY FLOW AND FORMING IN SAID VESSEL A VORTEX SINK AND A VORTEX SOURCE SPACED FROM EACH OTHER ALONG SAID PRIMARY FLOW AXIS; SAID NOZZLE MEANS TERMINATING FLUSH WITH THE WALL OF THE VESSEL AND BEING PROVIDED WITH MEANS DEFINING PROTUBERANCES FOR PRODUCING TURBULENCE IN THE FLUID INJECTED INTO SAID VESSEL FROM SAID NOZZLE MEANS, AND MEANS FOR COLLECTING THE SEPARATED MATERIALS IN THE LOWER PART OF THE VESSEL.