US 2846024 A
Description (OCR text may contain errors)
Aug. 5, 1958 T. BREMI 2,846,024
CYCLONE Filed May 21, 1956 INVENTOR: THEODOR' BREMI United States Patent CYCLONE Theodor Bremi, Winterthur, Switzerland, assignor to Schweizerische Lokomotiv-und Maschinenlabrik, Winterthur, Switzerland Application May 21, 1956, Serial No. 586,075 Claims priority, application Germany May 26, 1955 4' Claims. (Cl. 18388) This invention relates to a cyclone for separating impurities, especially liquid additions for gases or vapors. One type of such apparatus comprises a gas admission duct opening tangentially into the Whirl chamber, a centrally arranged gas vent and an outlet for the impurities near the bottom of the apparatus.
It is generally known that in this conventional type of cyclone the rotation of the gases in the whirl chamber is disturbed by the entering gas jet impinging on the rotating gases, whereby already separated particles return to the center of the cyclone and escape through its vent. In order to avoid this inconvenience, it has been proposed to guide the entering gas stream for a certain length in the chamber of rotation by providing a continuation of the admission duct within the cyclone, maintaining the place of entrance of the duct and its crosssectional shape.
The guiding of the entering gases, however, disturbs the rotational flow in another way, it decreases the whirl of the flow and lowers the rate of separation of the apparatus. Cyclones are also known in which the gas stream approaches the whirl-chamber along a spiralshaped path.
The object of the present invention is to provide a cyclone structure which eliminates the above-mentioned drawbacks.
According to the invention the cyclone comprises a gas conduit within the receiver consisting of a duct which is closed along the top and open along its bottom, the duct being narrow in radial direction as compared with the radius of the receiver and extending along the inner wall of the receiver over a portion of its circumference.
An embodiment of a cyclone according to the invention is illustrated in the accompanying drawings in which:
Figure 1 is a vertical section through the axis of the apparatus,
Figure 2 is a horizontal sectional view along the line IIII of Figure 1,
Figure 3 is a horizontal sectional IIIIII of Figure 1.
The gases to be purified enter the apparatus through an inlet connection 1. This connection gradually changes its cross-sectional shape in the direction of flow of the gases, the width of the connection becoming considerably narrower and its height increasing; the smallest width is designated by a (Figure 2). The stream of gases thus enters the receiver 2 in tangential direction in the form of a narrow fluid ribbon with high velocity. In the interior of the receiver the gases are guided in a narrow duct 3 formed between the wall 4 of the receiver, a curved guide wall 5 and a helically inclined covering lid 6. The width 12 of this duct 3 does not change. The guide wall 5 extends into proximity of the bottom wall 14 of the receiver and the duct 3 is open towards below.
Owing to the described manner of guiding the gas stream, the impurities contained therein are brought very view along the line 2,846,024 Patented Aug. 5, 1958 close to the inner wall surface of the cyclone, so that these impurities, withthe exception of very small particle sizes and minute droplets impinge against the wall. The liqiud particles, once adhering to the wall portion 4 of the duct 3 will form a continuous liquid layer and any disturbing whirls will not be able to suck particles of liquid out of this layer and carry them along again.
Since the narrow duct 3 is open at its lower end 11, the current of gases, after leaving the inlet connection, following its narrowest portion at 7, is free to develop according to its own laws. According to the flowresistances which the current encounters at the guidewalls, the velocity of the current will gradually diminish and the current beams will spread in the manner of a fan, substantially as indicated by the arrows 8.
When leaving the guide duct at 9 the primary gas current shows a pronounced downwardly directed compd nent. This latter assists in moving the separated layer of liquid adhering to the wall 4 downwardly, so that the greater part ofit will leave through the outlet 12. During the further whirling movement of the gases in the receiver 2, this movement is by no means disturbed by the guide wall 5, since this wall, owing to its small clearance from the wall 2 of the receiver deflects the whirls only to a small extent from the true circular course.
As shown in Fig. 3 the guide wall 5, on the side of entrance of the gas stream, is connected in the manner of a pocket with the wall of the receiver 2 below the gas inlet opening 7, so that at the point of connection no flow disturbing whirls can be formed and enter from the rear into duct 3. This pocket-like connection 10 extends substantially along a vertical line. It has further been proved that the ratio of separation is favoured when the lower edge 11 of the guide-wall 5 is arranged in a plane substantially at right angles to the axis of the cyclone.
The plate 13 near the bottom 14 of the receiver serves to impart a diameter as large as possible to the rising whirls and to prevent any transverse disturbing whirls from dragging separated liquid which already reached the bottom 14 upwardly again. In order that the central whirl space immediately below the vent pipe 15 is kept free of whirls as much as possible, a guard 16 is provided below the pipe which forces the diameter of the rising circular gas whirls not to drop below a certain minimum.
1. A cyclone for the separation of impurities from gases and vapours comprising a cylindrical receiver with a top and a bottom forming a whirl chamber, a gas inlet duct adjacent the top of said receiver opening tangentially thereinto, a wall closely spaced from the interior wall of said receiver containuing said duct within said receiver to direct the gas ar vapour stream circumferentially and downwardly of said receiver as a narrow fluid ribbon, said duct within said receiver being closed at its upper edge and open at its lower edge, said duct within said receiver extending downwardly until adjacent the bottom of said receiver, a central gas vent located in the top of said receiver, said receiver having an outlet adjacent the bottom thereof for the discharge of impurities, said duct within said receiver extending through a minor portion of the total circumference of said receiver with a narrow radial width compared to the radius of said receiver, said whirl chamber being formed for the major portion of its height partly by the inner wall of said receiver and partly by the inner wall of said duct whereby the whirling gas and vapour stream circulates along paths deviating only slightly from a 3 true circular path before being discharged through said gaslvent.
2. A cyclone for the separation of impurities from gases and vapours comprising a cylindrical receiver with a top and a bottom forming a whirl chamber, a gas inlet duct adjacent the top of said receiver opening tangentially thereinto, a Wall closely spaced from the interior wall of said receiver continuing said duct within said'receiver to direct the gas or vapour stream circumterentially and downwardly of said receiver as a narrow fluid ribbon, said duct within said receiver being closed at its upper edge by a closure extending diagonally downwardly from said gas inlet duct adjacent the top of said receiver to the exit edge of said wall closely spaced from the interior wall of said receiver and being open at its lower edge, said duct within said receiver extending downwardly until adjacent the bottom of said receiver, a central gas vent located in the top of said receiver, said receiver having an outlet adjacent the bottom thereof for the discharge of impurities, said duct within said receiver extending through a minor portion of the total circumference of said receiver with a narrow radial width compared to the radius of said receiver, said whirl chamber being formed for the major portion of its height partly by the inner wall of said receiver 4 and partly by the inner wall of said duct whereby the whirling gas and vapour stream circulates along paths deviating only slightly from a true circular path before being discharged through said gas vent.
3. A cyclone as set forth in claim 2 wherein said central gas vent comprises a conduit extending into the interior of said receiver and a guard plate is connected to said conduit and spaced therefrom in order to maintain the diameter of the circulating gas whirls above a certain minimum value. 7
4. A cyclone as set forth in claim 2 wherein a plate is mounted upon the bottom of said receiver and spaced therefrom to increase the diameter of the rising whirls of gas.
References Cited in the file of this patent UNITED STATES PATENTS 1,344,146 Peck June 22, 1920 1,402,784 Moore Jan. 10, 1922 1,717,369 Clements June 18, 1929 1,818,742 Paradise Aug. 11, 1931 2,295,101 Dunham Sept. 8, 1942 2,590,754 Cline Mar. 25, 1952