US2506298A - Fluid stream directing means - Google Patents

Description

' y 17950 R. GRIFFEN 2,506,293

FLUID STREAM DIRECTING MEANS Filed Aug. 9, 1947 w 7 INV ENTOR.

7 11* BY I]? 4' 1 \m WMKM [I L ATTORNEY Patented May 2, 1950 UNITED STATES PATENT ()FFICE FLUID STREAM DIRECTING' MEANS Ralph Griiifen, Detroit, Mich., assignor to American Blower Corporation, Dearborn, Mich, a corporation of Delaware Application August-9, 1947, Serial No. 767.777

2 Claims. 1

This invention relates to new and useful im provements in means for changing the direction of rotary motion of a fluid stream.

An object of this invention'ls to provide a de vice for reducing the rotation of afluid stream having a spiral motion.

Another object of this invention is to provide a device for changing the direction of motion of arotating fluid stream from a spiral motion to a longitudinal motion.

Another object'ofthis'invention isto provide a' centrifugal separator unit for removing foreign particles from a gas stream and-to provide efii cient'reconversion of kinetic energy of the Totating cleaned'gas into potential energy thereby lowering the drop in static pressure across the unit.

Other objects of this invention will become a1 parent'from time to timethroughout the specificationand claims as hereinafter stated.

In the accompanying drawings, to be taken as a part of this specification there is clearlyand fully illustrated a-preferred embodiment of this invention, in which drawing- Figure 1 is a'viewinlongitudinal'cross section of a centrifugal'type separator or dust collector having an inlet spinner and an outlet straightening member shown in full elevation;

Fig. 2 is an end elevation of the straightening member of Fig. I seen from the line-22 of Fig. 1.

Referring to the drawings by characters of'reference there is a centrifugal type'separator-or dust collector I having an inlet conduit s'and an inlet spinner member 3. The inlet conduit 2 has an end portion 4 for attachment to'a gas or air supply. The inlet conduit 2 is operable to receive a dust or particle laden air or gas which passes through the spinner member 3 andis given a rotary motion thereby throwing the particles toward the walls of the conduit 2. An outlet conduit 5 is positioned in theoutlet end portion 6 of the conduit 2 and has an end portion 1 for attachment to' another conduit. The annular space 8 between the conduit E'and the conduit end portion 6 isiclosedby an.-annular plate or cover member 9 having a plurality of apertures 9a therethrough for removal oftheparticles thrown toward the walls of the conduit-2. Each of the aforementioned apertures has. a helical vane member I I3 leading to it for directing theparticles Y for removal with a minimum amount of turbulence. The cover member 9 and apertures therethrough perform the additional function of re stricting the flow of gas through the annular space 8 so as to prevent diversion of clean gas iii thereto from theinlet portion of the conduit 5. In theinlet'end portion I I of the conduit 5 there is :a vanedj-.member I2 for changing the spiral motion of thengas to 'a longitudinal motion. The

- vaned member I2 has a streamlined body member I3 whichis rounded at the end facing gas flow and tapers toward its rear end portion I5. .A plurality of curved vanes I4 are carried by the body member I3 and are affixed thereto attheir inner peripheries. The -outer peripheries of the vanes-I4 :lie substantially on the surface of a cylinder of approximately the same diameter as the inside diameter of the conduit end portion I I and fit tightly thereagainst when the member I2 is inserted therein. The vanes I4 are helically curved toward the rounded end portion. ofthe body member, I3 for intercepting the spirally moving :ga-s substantially tangential to the spiral path of motion of the gas and gradually reduce in curvature toward the rear end portion I5 so .they'terminatein plane-portions I6 running the planexof the axis of the conduit 5. The 'va-ned member I2 .is positioned in the inlet end It of-the conduit 5 with a substantial portion thereof extending out from the end portion II. The ends of the vanes I lfacing gas flow terminate substantially in a plane transverse to and 'at -the point of maximum diameter of the body member I3 so' that the rounded end of the body member iB'extends beyond the ends of the vanes. Theamount of curvature of the vanes I4 and the dis'tance'from their ends to the end portion I I of the conduit 5 will vary slightly with the contemplated conditions of operation. If the member I2 is intended to be used with a gas having a high spiral velocity the helical angle of the ends of the'vanes I i will'b'esharper to intercept the gas stream with-maximum efficiency and the distance from the ends- 0f the-vanesto the end portion II will be less. If the member I2 is to be used with a gas having a low spiral velocity, the angle'of the-vanes and distance to theend portion-I I will be greater. The vanes M in changing the'directi'on oimotionof the gas stream passing therethrough from a spiral-motion to a longitudinal motion perform the additional function of increasing the head pressureon the gas stream and simultaneously' reducing turbulence so that some ofthe power lost in forcing the gas stream throughtheinlet' spinner 3 is thereby regained.

In operation, a particle laden gas stream enters the conduit 2 through the spinner 3 which imparts a spiral or rotary motion thereto. The spiral motion given the gas stream operates to throw the particles by centrifugal force towards M of the member l2 which extend out from the end portion H of the conduit '5 and is directed by the vanes I l into the conduit and straightened in its motion by the described change of curvature of the vanes hi. Thus it is seen that a gas stream is given a spiral motion for separatlng foreign particles upon admission to this separator and by the use of the straightening member i2 is restored to its longitudinal movement upon emerging therefrom. It should be further noted that when the incoming gas passes through theinlet spinner 3 it is accelerated and the poten tial energy of the gas is transformed into kinetic energy of rotation resulting in a pressure drop across the spinner 3. The rotating gas upon intercepting the vaned member I2 is restored to a longitudinal motion with the result that the kinetic energy of rotation is transformed into potential energy of static pressure and a considerable amount of the pressure lost in passing the spinner 3 is regained, thereby decreasing the drop in static pressure across the unit as a Whole.

What is claimed and is desired to be secured by Letters Patent of the United States is: 1. In a' centrifugal separator, a conduit for receiving a gas stream laden with foreign particles, "'2; spinner member for imparting a rotary motion to said gas stream to throw said foreign particles towards the walls of said conduit to cause said particles to concentrate in the portion of said gas stream adjacent the walls of said conduit thereby dividing said gas stream into a central clean portion and a concentrated particle laden outer portion, a second conduit of smaller diameter having its inlet end extending concentrically into the outlet end of said first-named conduit and operable to receive said clean central portion of said gas stream, a vaned member positioned in the inlet end of said second conduit for reducing the rotation of said gas stream central portion, said varied member having a plurality of vanes for receiving and directing the movement of said gas stream central portion, said vanes being helically curved from their lines of initial contact with said gas stream and reducing in curvature toward the discharge end of said vaned member within said second conduit, the change of curvature of said vanes being such that said gas stream central portion will be substantially free from rotation and turbulence upon emerging from said varied member, a plate member fitting around said sec-- ond conduit and joined to said first-named conduit and having at least one aperture for the discharge oi particle laden gas from the annular space between said conduits, said plate member having a vane portion leading to said aperture, said vane portion being operable to intercept said particle laden gas portion substantially tangential to its direction'of motion so that said particle laden gas portion may be discharged with little 4 turbulence, and said plate member being operable to restrict the flow of gas through the annular space between said conduits thereby to prevent said clean central portion of gas from being deflected into said annular space by said vaned member.

2. In a centrifugal separator, a conduit for receiving a gas stream laden with foreign particles, means for imparting a rotary motion to said gas stream to throw said foreign particles towards "the walls of said conduit to cause said particles to concentrate in the portion of said gas stream adjacent the walls of said conduit thereby divid ing said gas stream into a central clean portion and a concentrated particle laden outer portion, a second conduit of smaller diameter positioned into the outlet end of said first-named conduit and operable to receive said clean central portion of said gas stream, a vaned member positioned in the inlet end of said second conduit for reducing the rotation or" the gas stream passing therethrough, said member having a body portion of streamlined construction having a rounded frontal portion facing the gas stream and taper ing longitudinally in the direction of gas flow, a plurality of vanes for directing the movement of said gas stream central portion, said vanes being affixed to said body portion along their inner periphery and fitting tightly against the Walls of said second conduit at their outer periphery, said vanes being helically curved at the end of said body portion facing gas flow and intercepting the gas stream central portion substantially tangential to the direction of motion of the same and decreasing in curvature longitudinally in the direction of gas flow terminating in straight portions running in the plane of the axis of said second conduit, and said body portion and the helically curved portion of said vanes extending outside the inlet end of said second conduit to receive and direct said gas stream central portion into said second conduit and to change its direction of movement from a spiral motion to a motion substantially parallel to the axis of said second conduit, a plate member surrounding said second conduit and extending across the annular space between the ends of said conduits and hav-- ing at least one aperture for the discharge of particle laden gas, said plate member having a heli cal vane portion leading to said aperture, said vane portion being operable to intercept said particle laden gas portion substantially tangential to its direction of motion so that said particle laden gas may be discharged with little turbulence, and said plate member being operable to restrict the iiow or" gas through the annular space between said conduits thereby to prevent said clean central portion of gas from being deflected into said annular space by said varied member.

RALPH GRIFFEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name A Date 1,146,218 Kamrath Feb. 4, 1930 1,876,092. Harper Sept. 6,1932

' 2,370,629 Appeldoorn Mar. 6, 1945 2,393,112 Lincoln Jan. 15, 1946

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